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Development of a Comprehensive Safety Checklist for Tilt-Up Construction

Permanent Link: http://ufdc.ufl.edu/UFE0023879/00001

Material Information

Title: Development of a Comprehensive Safety Checklist for Tilt-Up Construction
Physical Description: 1 online resource (66 p.)
Language: english
Creator: Vickers, Jacob
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2008

Subjects

Subjects / Keywords: checklist, construction, safety, tilt, up, wall
Building Construction -- Dissertations, Academic -- UF
Genre: Building Construction thesis, M.S.B.C.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: It was determined after researching the safety information available to the construction industry regarding tilt-up construction that vital safety concerns were missing from available data. In addition, the available information was commonly improper for use on actual construction jobsites. The aim of this study was to improve the safety information available to the construction industry regarding tilt-up construction. Available tilt-up safety information was improved by creating an all-inclusive, comprehensive safety checklist for tilt-up construction. Additionally, a second tilt-up safety checklist relevant for use in the field was created; highlighting only the safety procedures to be followed during the tilt-up panel erection process.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by Jacob Vickers.
Thesis: Thesis (M.S.B.C.)--University of Florida, 2008.
Local: Adviser: Hinze, Jimmie W.
Local: Co-adviser: Issa, R. Raymond.

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2008
System ID: UFE0023879:00001

Permanent Link: http://ufdc.ufl.edu/UFE0023879/00001

Material Information

Title: Development of a Comprehensive Safety Checklist for Tilt-Up Construction
Physical Description: 1 online resource (66 p.)
Language: english
Creator: Vickers, Jacob
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2008

Subjects

Subjects / Keywords: checklist, construction, safety, tilt, up, wall
Building Construction -- Dissertations, Academic -- UF
Genre: Building Construction thesis, M.S.B.C.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: It was determined after researching the safety information available to the construction industry regarding tilt-up construction that vital safety concerns were missing from available data. In addition, the available information was commonly improper for use on actual construction jobsites. The aim of this study was to improve the safety information available to the construction industry regarding tilt-up construction. Available tilt-up safety information was improved by creating an all-inclusive, comprehensive safety checklist for tilt-up construction. Additionally, a second tilt-up safety checklist relevant for use in the field was created; highlighting only the safety procedures to be followed during the tilt-up panel erection process.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by Jacob Vickers.
Thesis: Thesis (M.S.B.C.)--University of Florida, 2008.
Local: Adviser: Hinze, Jimmie W.
Local: Co-adviser: Issa, R. Raymond.

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2008
System ID: UFE0023879:00001


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1 DEVELOPMENT OF A COMPREHENSIVE SAFETY CHECKLIST FOR TILT-UP CONSTRUCTION By JACOB VICKERS A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLOR IDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN BUILDING CONSTRUCTION UNIVERSITY OF FLORIDA 2008

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2 2008 Jacob Vickers

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3 To my family.

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4 ACKNOWLEDGMENTS I thank m y parents for supporting me throughout my education and instilling in me at a young age the importance of hard work. I would also like to thank Dr. Brad Hobbs for his support, advice, and friendship, and for encourag ing me to write a thesis in lieu of less demanding graduation requirements. Dottie Beaupied proved to be an invaluable administrative asset to this research, and I am very thankful for the help a nd guidance that she provided. Without the insights and knowledge shared by Dr. Jimmie Hinze, this research would have undoubtedly been a much more painstaking process.

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5 TABLE OF CONTENTS page ACKNOWLEDGMENTS ............................................................................................................... 4 LIST OF TABLES ...........................................................................................................................8 ABSTRACT ...................................................................................................................... ...............9 CHAP TER 1 INTRODUCTION .................................................................................................................. 11 Overview ...................................................................................................................... ...........11 Problem Statement ............................................................................................................. .....11 Objective ..................................................................................................................... ............12 2 LITERATURE REVIEW .......................................................................................................13 History ....................................................................................................................................13 Benefits of Tilt-Up Construction ............................................................................................14 Tilt-Up Construction Process .................................................................................................15 Preparing the Tilt-Up Panel Forms .................................................................................. 16 Pouring the Concrete Tilt-Up Panels ............................................................................... 17 Lifting the Panels ............................................................................................................ .18 Tilt-Up Concrete Asso ciation Checklist .................................................................................19 Prior to Construction .......................................................................................................20 Prior to Erection Day .......................................................................................................20 At the Safety Meeting ...................................................................................................... 21 During the Lift ............................................................................................................... ..21 After the Lift ................................................................................................................ ....22 Tilt-Up Concrete Associ ation Safety Article .......................................................................... 22 Manufacturers Safety Recommendations ..............................................................................25 Dayton Superior ...............................................................................................................25 Equipment and crew ................................................................................................. 25 Panel preparation ......................................................................................................26 Day of erection: safety meeting ............................................................................... 26 During the lift precautions ........................................................................................ 27 Plumbing panels precautions ....................................................................................28 Bracing general ........................................................................................................28 Meadow Burke ................................................................................................................ 28 Lifting tilt-up panels .................................................................................................29 Panel erection information ....................................................................................... 29 Bracing tilt-up panels ...............................................................................................30 Occupational Safety and Health Administration .................................................................... 30 Recommendations ........................................................................................................... 30 Regulations ................................................................................................................... ...31

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6 Case Studies ............................................................................................................................32 Crane Safety ............................................................................................................................33 3 METHODOLOGY ................................................................................................................. 34 Previous Research and Da ta on Tilt-Up Safety ......................................................................34 Creation of a Survey for Tilt-Up Construction Safety ............................................................ 34 Distribution of the Survey .................................................................................................... ..35 Compilation of Survey Results and Checklist Development ................................................. 36 4 SURVEY RESULTS ..............................................................................................................37 Company Demographics ........................................................................................................ 37 General Safety Structure ...................................................................................................... ...39 General Tilt-Up Information ...................................................................................................39 Tilt-Up Safety Information .................................................................................................... .40 Accident History ..............................................................................................................40 Work Crew ......................................................................................................................41 Signalperson Duties ......................................................................................................... 42 Crane Release Procedures ............................................................................................... 42 Safety Meetings ...............................................................................................................43 Wind Speed Policies ........................................................................................................43 Contactor Safety Concerns ..............................................................................................44 Views on Other Contractor Accidents .............................................................................44 Important Safety Procedures ........................................................................................... 45 Validation .................................................................................................................... ....46 Summary ....................................................................................................................... ...46 5 CHECKLIST RESULTS ........................................................................................................47 Checklist Structure ..................................................................................................................47 Design of Tilt-Up Panels .................................................................................................47 Site Logistics Considerations ..........................................................................................48 Planning the Tilt-Up Sequence ........................................................................................ 50 Pouring the Panels ........................................................................................................... 50 Crane Set-Up and Operation ...........................................................................................51 Job Conduct .....................................................................................................................52 Rigging the Panels ........................................................................................................... 53 Preparing for Lifting ........................................................................................................54 Lifting the Panels ............................................................................................................ .55 Swinging the Panels ........................................................................................................55 Positioning and Bracing of Panels ...................................................................................56 Releasing the Crane ......................................................................................................... 56 After Crane Release ......................................................................................................... 57 Field Safety Checklist ........................................................................................................ .....58

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7 Lifting the Panels ............................................................................................................ .58 Swinging the Panels ........................................................................................................58 Positioning and Bracing of Panels ...................................................................................59 Releasing the Crane ......................................................................................................... 59 6 CONCLUSION .................................................................................................................... ...60 7 RECOMMENDATIONS ........................................................................................................ 63 LIST OF REFERENCES ...............................................................................................................64 BIOGRAPHICAL SKETCH .........................................................................................................66

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8 LIST OF TABLES Table page 4-1 Average annual income of survey respondents .................................................................38 4-2 Number of tilt-up projects completed by survey participants annually ............................. 39 4-3 Tilt-up construction as a percentage of responding firm s overall business ......................39

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9 Abstract of Thesis Presen ted to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Master of Science in Building Construction DEVELOPMENT OF A COMPREHENSIVE SAFETY CHECKLIST FOR TILT-UP CONSTRUCTION By Jacob Vickers December 2008 Chair: Jimmie Hinze Cochair: R. Raymond Issa Major: Building Construction Tilt-up construction is a type of construction that involves th e construction of concrete wall panels that are formed, poured, and cured on an on-s ite slab and then lifted into place by crane. Although accidents in tilt-up construction are un common, tilt-up construction is an inherently dangerous type of construction due to the sever ity of accidents that can and do occur. It is imperative that construction workers who work on tilt-up projects have a clean understanding of the safety procedures that must be followed in or der to create a safe working environment. This safety information should not only be all incl usive and comprehensive, but should also be presented in a format that would benefit worker safety during the erection process. It was determined after researching the safety information available to the construction industry regarding tilt-up constr uction that vital safety concer ns were missing from available data. In addition, the available informa tion was commonly improper for use on actual construction jobsites. The aim of this study was to improve the safety information available to the construction industry regardi ng tilt-up construction. Available tilt-up safety information was to be improved by creating an all-inclusive, comprehensive safety checklist for tilt-up construction. The checklist would take into account all aspects of the tilt-up process, from initial

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10 design of the project to integr ating the tilt-up panels into th e roof and slab structures. Additionally, a second tilt-up safety checklist re levant for use in the field would be created, highlighting only the safety procedures to be followed during the erection process.

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11 CHAPTER 1 INTRODUCTION Overview The Tilt-Up Concrete As sociation (TCA) repor ts that in 2005, over 753 million square feet of building space was created using tilt-up practices (Sauter 2008). Tilt-up construction is a type of construction that involves the construction of concrete wall panels that are formed, poured, and cured on an on-site slab and then lifted in to place by crane. The process begins by forming and placing the concrete panels on the building slab or on a separate casting bed specifically installed for this purpose. Once the concrete wall panels have sufficiently cured, crane rigging is attached to lifting inserts embedded in the concrete panel. A crane is used to tilt and then lift the panel to its proper location, wher e it is then plumbed and leve led by an erection crew. The concrete wall panels are temporarily braced un til all sections are properly joined to the foundation and roof. At this point the tilt-up panels are fully integrated in to the structure of the building, and the building is st ructurally sound. The hurried lifting, placing, and bracing of multi-ton concrete wall sections creates numerous safety hazards. Although safety precautions are regularly followed during the tilt-up pro cess, injuries and deaths still occur. Problem Statement Although accidents in tilt-up cons truction are uncommon, tilt-up construction is an inherently dangerous type of construction due to the severity of accidents that can and do occur. If a worker is caught in the path of a falling pane l that weighs multiple tons there is little hope of survival. It was found that safety informati on for tilt-up construction is very limited. The information that exists contains sh ortfalls and was deemed inappropria te for use in the field. It is imperative that construction workers who work on tilt-up projects have a clean understanding of the safety procedures that must be followed in or der to create a safe working environment. This

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12 safety information should not only be all incl usive and comprehensive, but should also be presented in a format that would benefit worker safety during the erection process. Accidents in tilt-up construction can be prevented when safety procedures are presented in the proper format and put to practice by all parties involved in tilt -up construction projects. Objective It was determ ined after researching the safety information available to the industry that vital safety concerns were missing from availabl e data. In addition, the available information was commonly improper for use on actual constructi on jobsites. The aim of this study was to improve the safety information available to the construction indus try regarding tilt-up construction. Available tilt-up safety inform ation was to be improved by creating an allinclusive, comprehensive safety checklist for tilt-up construction. The checklist would take into account all aspects of the tilt-up process, from initia l design of the project to integrating the tiltup panels into the roof and slab structures. Additionally, a second tilt-up safety checklist relevant for use in the field would be created, highlighting only the safety procedures to be followed during the erection process.

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13 CHAPTER 2 LITERATURE REVIEW History Tilt-up construction experienced a major gr owth boom in the 1990s. The basic idea of casting a concrete wall on the ground and then lifting, or tilting, it into place has been around since the Roman Empire and the middle ages (R eed Business Information, Inc. 2007). Credited as being the father of concre te tilt-up construction, Robert H unter Aiken introduced the first form of concrete tilt-up construction to the construction industry in 1893 (Dayton Superior 2007). Although Aikens form of tilt-up constructi on did involve the liftin g and placing of jobcast concrete wall forms, it differed from presentday tilt-up practices. The early tilt-up projects did not have mobile cran es capable of lifting the wall panels into place. To tilt the walls into place, Aiken used block-and-pulley derrick s and horsepower (Johnson 2002). He proudly reported that it took only three days to cast a concrete wall panel on a steel frame and then lift it into place (Johnson 2002). Dramatic improvements were made in industrial and construction machinery to help the military effort in World War II. This produced a mobile crane powerful enough to lift concrete tilt-up wall panels. After the war, this crane became available to contractors in the private cons truction industry. At the same time, American industrial and manufacturing industries experi enced substantial growth, whic h demanded the construction of warehouse-style buildings (Reed Business Information, Inc. 2007). Modern tilt-up construction, still in its infancy, was a perfect match for the large single story buildings that needed to be built quickly and cost-effectively. From the initial demand for tilt-up construction in the 1940s, the practice has continually grown in popularity. In the 1960s, contractors who built warehouses, shopping centers, and office build ings adopted tilt-up construction, but it was not until the 1990s that tilt-up c onstruction experienced its most dramatic growth (Barreneche

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14 1995). In 2005 alone, over 753 million square f eet of building space was created using tilt-up practices (Sauter 2008). The Tilt -Up Concrete Association reports that currently about 15% of all industrial buildings are built using the tilt-up method (Sauter 2008). Tilt-up construction has evolved from Robert Hunter Aikens initial met hod of using a five horsepower motor to lift wall panels into place, to a method that now utilizes mobile cranes capable of lifting 300,000 pound panels that reach 100 feet in hei ght. Safety concerns associated with this growingly popular type of construction have also increased (Johnson 2002). Benefits of Tilt-Up Construction The num erous benefits of tilt-up construction when compared to masonry, wood frame, or pre-cast construction techniques are incr easingly becoming comm on knowledge in the construction industry. Having gained the attention of owners, developers, architects, engineers, and contractors, tilt-up buildings are becoming the preferred construction method for a diverse range of building types. This ha s in turn created the need for in creased attention to safety. The Tilt-Up Concrete Association ha s reported that in 2005 approxim ately 301 million square feet of wall panels were constructed us ing tilt-up techniques (Sauter 2008) Key benefits of tilt-up construction include speed, cost savings, a nd safety, when recommended procedures are followed. Tilt-up construction is typically used when fa st delivery of the building is a necessity. By casting wall panels on site that will be used as structural elements of the building, time is saved. Subcontractors do not have to wait for pre-cast pa nels to be fabricated and delivered to the jobsite before they can begin installing the wall pa nels. Once the concrete panels that were cast on site are properly cured to the ap propriate strength, they can be prepared to be tilted and lifted into place. Aside from roof joists and girders, th ere is often limited need for structural steel in tilt-up buildings. After the wa ll panels are erected and prope rly connected to the roofing

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15 structure, the buildings overall structure is essentially complete, thus saving time by not having to make numerous field connections to structural steel elements. Tilt-up construction might not always be the most cost effective method of construction, e.g. some buildings are too small or complex to economically justify bringing in heavy-duty cranes and pouring temporary ca sting platforms. On many occa sions, using tilt-up construction can save money for the owner and contractor. A pa rticular factor of cost efficiency associated with tilt-up construction is that there is no need fo r a separate exterior finish. Tilt-up panels can be cast to reflect the type of ex terior finish desired by the owner and architect. The project team of a two-story retail building in Charlotte, No rth Carolina, built by Choate Construction Group, saved $140,000 by using tilt-up panels instead of the pre-cast exterior skin that was specified in initial designs (Bracker 2008). Another cost-savings factor associ ated with tilt-up construction is the reduction in construction field personnel. Whereas the installation of structural steel, concrete masonry units, and wood frames require s substantial numbers of field personnel to install large structures within specified schedul e allowances, tilt-up panels can be lifted into place quickly with the use of 4 or 5 workers, including a rigger/signal man, crane operator, and workers to brace the panel. Not only does tilt-up construction save time and money, it also puts less people at risk by limiting th e number of workers involved in the construction process. Although fewer workers are on site and in harms way, the devastating consequences of a tilt-up accident are as heavy as the panels themselves. If a tilt-up panel falls during the lifting process there is very little hop e of survival for anyone who is caught in the falling panels path. Tilt-Up Construction Process A thorough descrip tion of the tilt-up process will be provided. This will help to understand the safety issues that must be addressed. As with any construction activity th at is expected to be safely and efficiently completed on time, the pro cess that utilizes tiltup wall panels should be

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16 thoroughly and completely planned in advance. In August 2002 an article was published in Practice Periodical on Structural Design and Construction entitled Description of Tilt-Up Concrete Wall Construction, written by Josh Ruhnke and Cliff J. Schexnayder. The article gives a step-by-step description of the tilt-up construction process. Details of the case history that pertain to tilt-up safety ar e also described. The construction project selected for the case history was a 40,000 square foot warehouse/ shop/office in Tempe, Arizona (Ruhnke and Schexnayder 2002). Preparing the Tilt-Up Panel Forms Actual tilt-up work begins afte r the building slab has been p oured. In the case study, the concrete contractor, Jack Hatfield Concrete Inco rporated, poured a 5-inch thick con crete building pad to be used as the casting platform. A 1.5-fo ot gap was provided between the outside edge of the slab and the interior edge of the erected exterior location of the tilt-up wall panels. This gap would accommodate a strip footing around the perime ter of the initial sla b. This footing will help to secure the erected tilt-up panels. In al l, 42 tilt-up panels were formed on the slab, which ranged in size from 27 to 31 feet tall and 20 to 30 feet wide. Before c oncrete was poured in the forms to make each individual panel, internal elemen ts of the panels were placed in their proper locations. These internal elements included reinforc ing steel to give the panels lateral and tensile strength, electrical conduits for outlets and other electrical devices, blockouts for doors and windows, lift and brace point inserts for the lifting and setting process, and ledger plates for the roof joists to rest on. Of particular interest for safety concerns were the inserts placed at the brace and lift points. On the project deta iled by Ruhnke and Schexnayder, a B-75 coil manufactured by Meadow Burke was used to att ach the temporary braces from the wall panel to the floor slab. The B-75 coil insert has four chair legs that extend horizontally from the base of a 3/4 inch diameter bolt hole (Ruhnke and Schexna yder 2002). B-75 coil inserts can also be used

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17 to attach strongbacks to thin or weak sections of the panel for a dded support. In addition to the B-75 coil inserts, Super Lift III inserts were adde d to the panels for lifting purposes. A Super Lift III insert leaves a metal loop exposed in the concrete wall panel to which the cranes rigging is attached (Ruhnke and Schexnayder 2002). Lifting insert locations should be placed in the exact locations specified by the ce rtified engineer of record to ensure that the panel is lifted correctly and safely. With the size and weight of the tilt-up panels, it only takes one mistake, such as incorrect insert installation, to cause an unstable and potenti ally dangerous lifting situation (Ruhnke and Schexnayder 2002). If the lif ting inserts are placed incorrectly there is a greater possibility that the cab le, rigging, or insert used to lift the panel will fail. Pouring the Concrete Tilt-Up Panels After the tilt-up wall panels were form ed and all items to be embedded in the concrete were correctly placed, concrete was poured into the wall form s. The supply of ready-mix concrete to the jobsite was constant enough to avoid cold joints in the wall panels. Cold joints would reduce the concretes strength and ultimately cause an unsafe enviro nment, even after the building was completed. The concrete mix design used for the wall panel had a compressive strength of 4,000 psi at 28 days, and a seve n inch slump (Ruhnke and Schexnayder 2002). During concrete placement three workers spread th e concrete, and two workers used vibrators to settle the concrete around all embe ds, reinforcing, and inserts. Whenever inserts, anchors, or other units are embedded it is necessary to ac hieve good consolidation of the concrete around each item. Without good consolidation of the conc rete, the embedment could possibly pull out at well below its expected load, causing a poten tially deadly working condition (Ruhnke and Schexnayder 2002). An important member of the c oncrete placing crew with regards to safety was the spotter. The spotters so le responsibility was to make sure that all embeds, inserts, and

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18 reinforcing steel remained in the proper locations and in acceptable wo rking condition while the concrete was being placed and finished (Ruhnke and Schexnayder 2002). Lifting the Panels After seven days of curing, th e concrete tilt-up panels were ready for erection. Burke braces, m ade by Meadow Burke, were attached to the B-75 coil inserts (Ruhnke and Schexnayder 2002). After braces were attached to the panels in the proper locations they were laid flat on the panels until a panel was prep ared for lifting (Ruhnke and Schexnayder 2002). In order to keep workers as safe as possible, it is imperative to attach braces to the wall panels before the crane lifts them to th eir final positions. Attaching braces to a wall panel while it is in the lifting phase puts the workers in a dangerous position in the event that the rigging were to fail. After the braces were att ached to all panels, the 300-ton mobile lattice boom crane began lifting the panels one at a time (Ruhnke and Sche xnayder 2002). The Burke braces served to temporarily brace the wall panels until all panels were in place and the roof trusses had been properly attached. The roof trusses give the bu ilding its permanent structural integrity. The crane operator and setting crew followed a predetermined lifting sequence that followed a clockwise pattern around the perimeter of the sla b. This helped ensure efficiency and safety (Ruhnke and Schexnayder 2002). Ruhnke and Schexnayde r describe the rigging of a panel to the crane in the following paragraph. The crane lowered a spreader bar, which had a pulley attached to each end. A single wire rope passes over each pulley, and each end of th at rope is connected to one of the two anchors along one edge of the panel. This provides a self-adjusting mechanism, which allows the panel to swing from the horizontal to the vertical position as it is lifted from the floor slab. The shackles are used to attach the wire rope to lift bails, and each lift bail is attached to a ring clutch. The ring clutch be ars on the concrete at the top of the void created by a plastic void former of the Super Lift III insert, and at the same time engages the anchor eye of the Super Lift III embedmen t. The manufacturer of the ring clutches, which are reusable hardware, reco mmends a safety factor of 5 to 1. For the lifting anchors, the recommended safety factor is 4 to 1.

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19 With the proper rigging in place, each panel was th en lifted to its position in the slab trench on the perimeter of the slab. During the erecti on process a ten-worker crew was used, which consisted of a crane operator, an oiler, two workers to carry the ends of the braces, two workers to guide the panel, two workers to connect the braces to the sla b, a worker to release the rigging, and a foreman who gave hand signals to th e crane operator (Ruhnke and Schexnayder 2002). First the panel was lifted, and then it was guide d into place by the crane and a worker on each edge of the panel. Next, each panel was put into its exact level and plumb location so that the braces could be attached to the slab by way of -inch expansion bolts (Ruhnke and Schexnayder 2002). These -inch anchor bolts were placed in pre-drilled holes in the slab. Ruhnke and Schexnayder do not recommend erecting tilt-up pane ls if winds exceed 20 mph, even though the braces used were capable of supporting the pane ls in winds of 60 mph. During the entire process, only the ten erection crew members were allowed with in a distance of 1times the height of the panel, this limited the number of workers subject to harm if a panel fell (Ruhnke and Schexnayder 2002). Before th e bracing was removed, the roof system was installed, and the reinforcing bars extending from the slabs peri meter and the bottom of the tilt-up panels were covered with concrete. This filled in the 1foot gap to complete the slab (Ruhnke and Schexnayder 2002). Tilt-Up Concrete Association Checklist The m ost comprehensive and all-inclusive safe ty checklist for tilt-up construction currently available to the construction i ndustry is produced by the Tilt-Up Concrete Association (TCA), and is entitled Safety Checklist for Concrete Tilt-Up Constructi on. The checklist is divided into five categories, based on the sequence of construction tilt-up panels : Prior to Construction, Prior to Erection Day, At the Safety Meeting, During the Lift, and After the Lift. The contents of

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20 each category are listed herein, taken directly from the Safety Checklist for Concrete Tilt-Up Construction (Tilt-Up Concrete Association). Prior to Construction Select an erection con tractor and/or crew experienced in handling tilt-up panels. Select a crane with a capacity capable of lif ting the heaviest panel plus the weight of the rigging gear. Obtain all crane certification documen tation and certification of insurance Verify design for a proper subbase under floor slab. This will be the casting area as well as a working surface. The slab is onl y as good as the sub base upon which it is placed. Check the floor slab for adequate strength to support the crane, if the crane will be on the floor slab. Obtain a properly designed and detailed tilt-up package signed and stamped by a professional engineer. Obtain a bracing manual with braces designed for the proper wind loads. Obtain approved shop drawings for each pa nel showing all pert inent information. Develop a panel casting and erection sequence. Verify the bondbreaker compatibility with all curing or sealing compounds, paint or sealers that may have been or will be used on the floor slab or panels. (Note: always test the bondbreaker befo re casting any panels.) Inspect the panel formwork for proper pl acing of reinforcing, inserts, embedded items, and dimensional accuracy. Prior to Erection Day Perform a site inspection. Look for a ny underground hazards, overhead wires, rough terrain, or soft subgrade upon which the cran e will travel. Make notations of any corrections that need to be made or any hazardous areas. Rig the crane prior to the date erection is to start. Verify that the crane is in good working condition. Perform final check for all lifting inserts (properly located), strongbacks (properly installed), and concrete stre ngth (attained required streng th), and note all information in the erection manual. Install entrance and exit ramps for the crane to position itself on the floor slab. Do not allow the crane to exert its weight on th e extreme edge of any portion of the slab. Check to make sure all the blockouts are cove red. (Note: if water were to get under the slab, it could weaken the subgrade and the crane may crack the slab.) Itemize the equipment required for a proper a nd safe lift. Ensure that the tools and equipment are well maintained. Identify erection subcontracto rs crew. A minimum crew should consist of the crane operator, rigger foreman, two journeym an riggers, and welders if required. Provide a clean working area with all debris and obstacles removed.

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21 Locate proper shim points on the footing to prevent overloading the footing prior to grouting under the panels. (Note: The engi neer of record can help you with these locations.) Hold a safety meeting before any lifting starts! Ensure that each member of the crew understands their position and the responsibility that goes with it. Establish a controlled access z one during erection of panels. At the Safety Meeting Review the TCA Workers Safety Checklist and have all crew m embers sign and check the list after the safety meeting. Instruct personnel never to place themselves: o Under a panel while it is being tilted, o On the blind side of the panel whil e the crane is traveling with it, o Between the crane and the panel, or o Between the panel being lifted and an adjacent panel. Instruct personnel to never o Allow horseplay or unnecessary talking o Reach their hands under a panel to adjust a shim or a bearing pad. Instruct personnel to o Remain alert at all times, looking out for fellow workers & other heavy equipment. o Wear proper and required attire at al l times (i.e. hardhats, shoes etc.). Address all fall protection requirements. Distinguish the rigging foreman with a colo red vest. Ensure the rigging foreman and crane operator understand all hand signa ls they will use to communicate. Instruct the other personne l that the only person who s hould signal the crane operator is the rigging foreman. Clearly define the function and responsibility of each person of the lifting crew. Demonstrate the use of the lifting hardwa re, bracing hardware, and proper use of tools and equipment to be used. Flag the cranes swing radius and provide crane operator with we ights of individual panels and instruct ope rator on lifting sequence. During the Lift Maintain a clean workin g area with all debris and obstacles removed. Do not lift panels when wind conditions would produce unsafe conditions during a lift. Keep any personnel not involved with the pane l lifting procedure clear of the lifting area. Maintain fully-extended outriggers and use cr ibbing to spread the outrigger loading. If outriggers cannot be fully extended, then the crane cap acities must be reduced. Inspect all rigging gear prior to loading the inserts for proper alignment and free of snags.

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22 Verify the rigging configuration matches that are shown in the erection manual. Check to be sure that braces will not be trapped by the ri gging once the panel is in its final position. Be alert for panels that may be stuck to the casting surface. Loads to the lifting inserts may be twice that designed fo r causing possible insert withdrawal. Carefully release the panel using pry bars and wedges. Be alert to all obstacles in the path of th e crane and the crew, es pecially if you must walk a panel. Take extra precautions when lifting panels with special shapes or special rigging. Do not use any damaged or bent braces, lifting hardware or bolts. Make certain that any str ong backs shown on the erection details are included on the panels. After the Lift Be alert when plum bing panels to their fina l upright position. Be sure that the panel being plumbed does not strike anot her previously erected panel. Plumb panels as close as possible prior to attaching braces to the floor slab. Never release the crane load if the bracing does not appear adequate. If the bracing design calls fo r a support system of knee, la teral, end or cross bracing, it should be checked for complete installa tion prior to releasing the crane load. If the lateral and end braci ng cannot be installed with the panel load still on the crane, the completion of this bracing must not be further than one panel behind the lifting schedule. All bracing should be installed on all erec ted panels at the end of the work day. At the beginning and end of the work day, ch eck all brace inserts to ensure that they are tight and have not worked loose throughout the night or day. If at all possible, grout u nder all erected panels prior to the end of the work day. Do not remove any braces until all the stru ctural connections are completed and the lateral resistive system is in place and comp leted. The structural engineer of record can help you determine if it is safe to remove any or all of the panel braces. Be careful when backfilling the pour strip so that you do not exert excessive pressure on the tilt-up panel. Tilt-Up Concrete Association Safety Article In addition to the Safety Checklist for Concre te Tilt-Up Construction, by the TCA, an article wr itten by Jim Baty of the TCA entitled Tilt-Up Safety Inherent When Planned, was published in 2008 in the organizations newspaper, Tilt-Up TODAY volume 15, number 4. The article by Baty notes that the TCA has partnered with the American Concre te Institute (ACI) to create a Tilt-Up Certification Program, which trains construction professionals as Certified

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23 Tilt-Up Technicians (Baty 2008). At the time of the article, 1,079 tilt-up professionals had been certified, and of these, 205 had received the stat us of Certified Tilt-Up Supervisor (Baty 2008). To become a Certified Tilt-Up Supervisor one must pass the program exam and submit evidence of at least five years work experience related to tilt-up construction (Baty 2008). Baty claims that one of the most attractive characteristics of tilt-up construction is its inherent safety qualities, evidenced by the facts that the reinforced concrete wall panels are constructed entirely in a horizontal position on the ground and then lifted only once to a vertical position and set into place with a continuous operation (Baty 2008). He al so noted that the number of workers is limited during the erection process, and after the panels are erected they are braced for safety until permanently integrated in to the building stru cture (Baty 2008). According to Baty, the first action that must ta ke place to ensure safety is proper planning. It is important for prime contractors to choose er ection contractors and crew s that have relevant experience in tilt-up construction, not only for safe ty, but also for efficiency. Once the panels are ready to be erected, Baty sugge sts that site and crane inspection are key to success and safety. The TCAs checklist includes identifying all overhead and ground level hazards, including soft subgrade. Also, be sure that the pre-determined crane path is clear of all obstructions, and both the crane operator and the crew know the planned route and any hazards that might exist. The crane operator should thoroughly inspect the cranes cables, tracks, tires, engine, and hydraulics. The contractor must ensure that the crane is powerful enough to safely lift the panels at all angles prompted by each individual jobsite. It is common practice to use a crane with the capacity to lift a panel that is 2 to 3 times the heaviest one on site to allow for variation in boom angle and distance (Baty 2008). Before attaching rigging to a panel, lifting inserts should be checked for proper location, cables should be checked for exce ssive wear, and the lift ing (spreader) beam

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24 should be checked for warpage and fatigue (B aty 2008). A safety meeting should take place before any action occurs, and during the entire preparation process crew members should carry a safety card or checklist as a reminder for safety a nd a record of proper safety instruction. Crew members must be reminded to wear proper atti re, and to not position themselves between the crane and the panel, between the panel being lifted and an adjacent panel, or on the blind side of the panel (Baty 2008). Only after all rigging, clutches, crane outriggers and cribbing, and cables have been checked may lifting proceed. If it is n ecessary to use pry bars or wedges to release the panel from the slab, make sure that they are used in line with lifting inserts, since more reinforcing is positioned there (B aty 2008). As a panel is being lifted, the foreman/rigger/signal person must look up to ensure that there are no twisted cables in the rigging, which could cause unwanted stress, thereby compromising the safety of the entire system. During the entire lifting and setting operation, only those workers who are members of the tilt-up erection crew should be allowed within a distance equal to 1times th e height of the panel (Baty 2008). Once the panel has been maneuvered into its proper position, and shimmed accordingly, braces should be checked for damage before using expansion bolts to connect them to the floor slab. Equipment now exists that allows the rigg ing to be disconnected from the tilt-up panel without requiring a worker to climb to the top of the panel to do s o, which eliminates the po ssibility of fall hazards (Dayton Superior 2007). Baty concludes the arti cle by again stating that accidents in tilt-up construction are a rarity, but that the few safety issues that do happen occur when panels are moving or when they are assumed to be pr operly braced or connected (Baty 2008). This remark is a reminder that all bracing and conn ections should be thoroughly checked everyday until the panels are permanently integr ated into the buildings structure.

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25 Manufacturers Safety Recommendations Product han dbooks and catalogs from tilt-up ma nufacturers can be a wealthy source of information on tilt-up safety. Not only do they list the rated stress allowances for inserts, lifting hardware, and braces, but they also regularly gi ve recommendations regarding general tilt-up safety procedures that should be followed. Public ations of tilt-up manuf acturers present safety recommendations that are generally only seen by specialty tilt-up contractors. Dayton Superior Dayton Superiors 2007 Tilt-U p Construction Product Handbook gives a generous amount of infor mation regarding tilt-up safety and effici ency. The instructions for panel erection are divided into six sections: Equi pment and Crew, Panel Prepara tion, Day of Erection Safety Meeting, During the Lift Precautions, Plumbing Panels Precautions, and Bracing General (Dayton Superior 2007). Equipment and crew Dayton Superior s first command is to itemize the rigging and equipment that will be needed for a proper and safe lift (Dayton Superior 2007). This is important to ensure that all necessary items are in place and accounted for. It is imperative to comply with all rigging configurations and cable lengths given in the instruction manual. Otherwise, the equipment may become over stressed, and possibly fail. Furthe rmore, it is the responsibility of the tilt-up erection contractor to choose the correct diamet er and strength lifting cable (Dayton Superior 2007). In anticipation of the even t that lifting hardware is inspect ed and found to be defective, Dayton Superior recommends that at least two extra lifting hardware units should be on the jobsite. Before erection begins, the jobsite shou ld be cleaned, and free of obstacles and hazards. The minimum erection crew recommended by Dayton S uperior consists of the crane operator, oiler (driver), rigger foreman, and two journe yman riggers (Dayton Superior 2007). As

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26 required, carpenters and laborers s hould be available to handle the braces. Additional laborers are required when panels are stacked. When stacking panels, often due to extreme space limitations, the panels are cast on e on top of another up to eight levels high. The key to successful and safe lifting is a p roperly staffed and well coordina ted crew that includes a crane operator who is able to cont rol the hoist, swing, and boom hoist motions of the crane simultaneously (Dayton Superior 2007). Panel preparation The first action recomm ended by Dayton Superi or to prepare the tilt-up panels is to remove all standing water from around the panel a nd in panel openings. If any standing water is present, it will prevent air from entering under th e panel, which creates a suction load that can be strong enough to cause the lifting inserts to be come overloaded and fail creating a potentially disastrous situation (Dayton Supe rior 2007). After all water is removed from the slab and around the panels, ensure that all inserts are in the prope r locations identified in the erection instructions. For time efficiency, make sure that all lifting hardware fits properly into the lifting inserts before rigging begins (Dayton Superior 2007). If strongbacks are requi red for a panel, install them properly for additional support. Before lifting may begin, the pa nels must obtain the specified compressive strength at the time of the lift, not the ultimate strength (Dayton Superior 2007). Finally, it should be verified that all braces attached to the panels are of the correct type and free of defects. Day of erection: safety meeting On the erection day, Dayton Superior recomm e nds that a safety meeting is held, which should be attended by a representative of the e quipment supplier. All personnel in the tilt-up crew should be told to never place themselves under the panel while it is being tilted or on the blind side of the panel when the crane is trav eling with it (Dayton Superior 2007). The crew

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27 should never horseplay; talking should only be al lowed if absolutely necessary. The safety meeting should be conducted by the rigger foreman, who should remind all crew members to remain alert, and that safety is everyones re sponsibility and that ha rd hats are required (Dayton Superior 2007). The ri gger foreman should be experienced in the tilt-up process, and know with certainty the hand signals used to communicate with th e crane operator. Although the rigger foreman should exude confidence and superi ority over the crew, he should also guard against overconfidence and carelessness. Dayton Superior also recomm ends that the rigger foreman should create a checklist to be signed by all crew member s at the end of the meeting. All members of the crew should know their assi gnments, and should be in a team of other workers with similar responsibilities. In addi tion to the clean up efforts recommended before the lift begins, it is advised that the rigger foreman should employ a laborer with the responsibility of cleaning the floor slab where the pa nel was cast as soon as it is lifted from the slab. This clean up effort includes removing all forming nails fr om the slab (Dayton Superior 2007). Dayton Superior is very clear on the fact that their rigging details are to be followed exactly. Spreader bar widths and cable angles are integral parts of the erection stress anal ysis (Dayton Superior 2007). All cable lengths and rigg ing scenarios given by Dayton Supe rior should not be adjusted unless a call is made to the technical department and an alternate method of rigging is approved (Dayton Superior 2007). If the integrity of the rigging is compromised, the entire erection crew faces unsafe working conditions. During the lift precautions When a panel is properly prepared to be lif ted, wind conditions should be m onitored. If wind conditions are strong enough to inhibit the crews ab ility to control the panel during the lift, the erection process should be postponed. Before th e slack is completely taken out of the cables, make sure that all rigging is properly ali gned (Dayton Superior 2007). The rigger foreman

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28 should be aware that cables may twist while bein g tightened, and could as a result rotate the hardware and cause side loading to occur. If this condition oc curs the lift should be stopped, and the hardware should be real igned (Dayton Superior 2007). Plumbing panels precautions Dayton Superior recom mends the following acti ons when plumbing tilt-up panels. When plumbing a panel, make sure that the panel being plumbed does not st rike a panel that has already been erected to avoid the possibility of knocking a panel ove r. Get the panel as plumb as possible while the panel is still at tached to the crane, but before bracing is connected to the slab (Dayton Superior 2007). If the panel is not plumbed prior to cr ane release when the bracing design calls for a sub support system of knee, lateral, and end or cross bracing, the bracing will have to be loosened to accura tely plumb the panel (Dayton Superior 2007). This creates a dangerous situation (Dayton Superior 2007). Bracing general It is advised by Dayton Superior to n ot release the crane from the panel if the panel bracing does not appear adequate. Although not all bracing can always be attached before releasing the crane, it is recommended that knee bracing is installed, at a minimum, before the crane is released. As a general rule, once the crane has m oved to the next panel, lateral bracing should be installed. This assumes that the crane inhib ited the installation of lateral bracing (Dayton Superior 2007). Before the work day is co mplete, all panels should be properly braced. Meadow Burke Meadow Burke, a m anufacturer of concrete tilt-up accessories, gives information and recommendations for the tilt-up process in the Meadow Burke Tilt-Up Manual. Within the manual are three major sections which give insigh t into the factors that determine a safe tilt-up

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29 construction project. The three sections are Li fting Tilt-Up Panels, Pa nel Erection Information, and Bracing Tilt-Up Panels. Lifting tilt-up panels Meadow Burke begins the recomm endations fo r panel lifting by addressing the importance of proper lifting insert positioning and rigging. During the lifting process, stresses in the concrete panel can be up to four times as much as structural stresses that the panel will encounter (Meadow Burke 2007). Engineers working for Meadow Burke have determined that the minimum compressive strength that should occur in concrete tilt -up panels before erection is 2,500 psi. It is recommended that a Test B eam Break (ATM C 78) and concrete cylinder compression tests be conducted prior to lifti ng panels (Meadow Burke 2007). For insert locations Meadow Burke recommends the services of their professional engineers, who have created sophisticated software th at locates the correct insert locations, taking into account all flexural and shear stress levels. Panel erection information Meadow Burkes Tilt-Up Manual g ives multiple illustrations accompanied by explanations of different rigging techniques. One rule that is applied to all rigging si tuations is that the cranes cable and boom must remain perpendicular to the panel during the beginning of the lift. Further, it must remain perpendicular to the cas ting slab with its line of action bisecting the sling angle throughout the lift (Meadow Burke 2007). This rule is to avoid high booming, when the crane boom is positioned too far towards the top of the panel, and low booming, when the crane boom is positioned too far toward the bottom end of the panel (Meadow Burke 2007). In each of these situations stresses are concentrated on one end of the panel, and if sufficient enough, could cause cracking of the panel and a dangerous situation.

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30 Bracing tilt-up panels Meadow Burke gives the following guideli nes for bracing, wh ich when followed will significantly reduce the likelihood of accidents resu lting from brace failure. The guidelines have been abbreviated directly from Meadow Burke s Tilt-Up Manual below. For the full narrative see Meadow Burkes Tilt-Up Manual. Braces are designed to be placed in a plane at 90 degrees to the face of the panel. Skewing a brace will reduce the load carryi ng capacity of the brace. The maximum horizontal skew of the braces is limited to 5 degrees. Due to the increased suction created on the backside of a panel with openings; do not increase the brace spacing for panels with openings, unless a complete wind analysis to determine the effects of the wind pa ssing through the openings is performed. Locate brace inserts 1 foot or more from all concrete edges and floor slab joints. Locate brace inserts to provide clearance between the lifting hardware and braces. Locate brace inserts symmetrically about th e panels centerline whenever possible. Locate the first brace insert from each end of the panel at a distance no greater than 25% the panels width or 10 feet, whichever is less. Locate brace inserts to create an equal wind load to each brace where possible. Brace inserts should not be placed lower than 60% of the panels height and not less than 5% of the panels height above the pa nels geometric centroid or mass center of gravity, whichever is greater. Occupational Safety and Health Administration The Occupational Safety and Health Adm i nistration (OSHA) realizes that tilt-up construction is potentially dangerous, and after investigating tilt-up accidents has created recommendations that should be followed by a ll contractors engaged in tilt-up construction activities. Recommendations An OSHA bulletin published in 2003 titled Tilt-Up Panel Construction Hazard, gives recommended safety procedures derived from a til t-up accident in North Carolina that left three workers dead. An investigation by the Nort h Carolina Department of Labor Division of Occupational Safety and Health determined that the victims took a lunch br eak in the shade of a

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31 20-ton concrete tilt-up panel, wh ich did not have proper support or bracing. All three workers were killed when the panel fell on them. Further, the investig ation revealed that 14 of the projects tilt-up panels were improperly brace d, or temporary bracing had been removed from them before the panels had been integrated into the structure of the building (OSHA 2003). The erection contractor failed to adhe re to project documents, which sp ecified that roof joists should be properly welded to all tilt-up panels, grout should be installed under all tilt-up panels, and pour back strips should be poured before the rem oval of temporary bracing. It was also noted in the OSHA bulletin that supervisors and employees lacked adequate knowledge about measures necessary to address hazards associated with t ilt-up construction (OSHA 2003). As a result of the accident and investigation, OSHA gave the following recommendations for tilt-up construction, taken directly from OSHAs 2003 safety bulletin on tilt-up construction: Employers shall initiate and maintain such programs as may be necessary to provide for frequent and regular inspections of the job site, materials, and equipment by designated competent persons. 1926.20(b)(1) through (2); Em ployers shall instruct each employee in the recognition and avoidance of unsafe conditions and the regulations applicable to his work environment to control or eliminate any hazard or other exposure to illness or injury. 1926.21(b)(2). For exam ple employers should instruct supervis ors and workers not to remove temporary braces until roof structure and/or columns are in place to stabilize the building; Employers shall comply with all of the requirements for precast concrete construction. 1926.704; Em ployers should ensure that tilt-up panels are properly braced to resist wind and lateral forces; Employers shall use only certified welders wh en welding steel joists to embeds and inserts on tilt-up wall panels. Regulations In addition to the recomm endations given by OSHA related to tilt-up construction, all tiltup operations are required to follow the regul ations of standard 1926.704, Requirements for Precast Concrete, as included in the Safety a nd Health Regulations for Construction, CFR 1926. The regulations of OSHA standard 1926.704 are given verbatim below.

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32 1926.704(a): Precast concrete wall units, structural framing, and tilt-up wall panels shall be adequately suppor ted to prevent overturning a nd to prevent collapse until permanent connections are completed. 1926.704(b): Lifting inserts which are embedde d or otherwise attached to tilt-up precast concrete members shall be capabl e of supporting at least two times the maximum intended load applied or transmitted to them. 1926.704(d): Lifting hardware shall be capable of supporting at least five times the maximum intended load applied transmitted to the lifting hardware. 1926.704(e): No employee shall be permitted und er precast concrete members being lifted or tilted into position except those em ployees required for the erection of those members. Case Studies In 2003 Concrete Construction published an article written by Hanley-W ood, Inc. titled Lessons for Life (Safety Report), which describes a tilt-up accident in 1 999 that left a concrete worker dead after being crushed by a falling tilt-up panel (Hanley-Wood, Inc. 2003). The accident occurred during the erection of the final three panels of a one-story warehouse. Two 12-foot nylon web slings rigged in a basket hitch were used to lift the remaining two panels simultaneously as the previous panel was being braced. As the two panels were suspended by the crane, one of the panels shifted in the sling, causing the edge of the panel to slice entirely through one sling, and partially through the othe r (Hanley-Wood, Inc. 2003). The victim was crushed by the first panel after it had been struck by the falling pa nels and knocked loose from its bracing. An OSHA spreadsheet of compiled construction industry fatalities gives the details of multiple tilt-up accidents, which are summarized as follows: A worker was removing strongbacks on a tilt-up pa nel when he fell to his death from the ladder. A worker was fatally crushed by a 92,000 pound panel. The erection crew was having difficulty plumbing a panel that was supported by a Manitowoc Lattice Boom Crane, and immediately prior to the accident was attempting to properly shim the panel. As the panel was being lowered it hit an adjacent panel and knocked it loose from its bracing. The victim was crushed by the falling panel.

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33 A worker was crushed by a 60ton tilt-up panel on a windy day. A carpenter leadman was on top of a tilt-up pa nel, making sure it was plumb. As he was stepping onto a ledger wall he slipped and fe ll over 34 feet, sustaining fatal injuries. Crane Safety In 2008, Concrete Construction Magazine pub lished an article titled W orking around Cranes, written by Kate Hamilton, that gave va luable safety information related to jobsites where cranes will be used to lift heavy items. The article notes that it is important to select the right crane for the job, and to always be aware of jobsite conditions. Accidents and unsafe conditions occur when cranes are improperly insp ected, set up incorrectly, or when the simple laws of physics are violated (Hamilton 2008). Overloading a crane can cause the crane to tip over, as was the case in a 1999 incident that invo lved the death of one worker after a crawlermounted crane fell over while transporting a 1-cu bic yard bucket of concrete (Hamilton 2008). Sometimes the geography of some jobsites may not allow a crane to fully extend its outriggers; a heightened state of caution should exist when such is the case, a nd the load capacity of the crane should be lowered accordingly. It is also important to note that the carryi ng capacity of a crane is reduced as the boom is lowered (Hamilton 2008). A crane safety procedure that is easily overlooked is to make sure that the forces ex erted by the crane do not exceed the soils loadbearing capacity (Hamilton 2008). It is vital to the safety and success of every tilt-up construction project that these cran e safety precautions are followed.

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34 CHAPTER 3 MEHODOLOGY After researching tilt-up construction safety in the literature, it was found that there is very lim ited information regarding safety procedures th at is appropriate for us e on actual construction jobsites. To develop a comprehensive jobsit e safety checklist for tilt-up construction, the researcher relied on a number of resources. The first resource wa s to glean relevant information from the published literature. Previous Research and Data on Tilt-Up Safety Previous res earch results a nd data on tilt-up safety tec hniques contributed to the determination that a comprehensive checklist for tilt-up safety, in a format that was useful on construction jobsites, was not yet available. A great wealth of info rmation involving tilt-up safety considerations, as well as general tiltup processes and practices, was obtained from the Tilt-Up Concrete Association (TCA). The TCA newsletter, Tilt-Up TODAY was accessed on their website, and the TCAs tilt-up safety ch ecklist was provided by Ed Sauter, executive director of the TCA. The TCA safety checklist constitutes a useful contribution to outlining safe work procedures with tilt-up c onstruction. Upon closer examinati on it was felt that this checklist would be a valuable resource for the research, but that additional safety co ncerns needed to be addressed and a reorganization of the informati on would be necessary. Additional information was found in articles published in co nstruction industry journals, such as Concrete Construction Construction Today, and Construction News Creation of a Survey for T ilt-Up Construction Safety Since it was felt that the literature did not re flect the full range of tilt-up practices, it was decided that additional information on current tilt-up practices was needed. It was decided to conduct a qualitative survey to obtain this info rmation. In order to understand the safety

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35 practices and safety needs of prime contractors and subcontr actors involved with tilt-up construction, a survey consisting of questions related to tilt-up sa fety procedures was developed. Survey questions were based on the followi ng topic areas: tilt-up crew size and the responsibilities of crew member s, crane safety, tilt-up safety meetings, the causes of tilt-up accidents, and a companys general safety cultu re. Questions about the demographics of respondents were also included in the survey. Questions were form ulated after reviewing articles on tilt-up construction with the inte nt of using the survey as a m eans of identifying current tilt-up safety practices and to also solic it safety suggestions directly from contractors. The survey was revised multiple times until the researcher and his committee chair agreed that the survey was appropriate for the acquisition of the desired information. Next the survey was sent to two different contractors for review. One contract or thought that the surv ey was adequate as submitted, while the other made some minor suggested changes. The suggestions were implemented into the survey as the researcher and committee chair felt appropriate. Distribution of the Survey After the survey was finalized, a survey population distribution lis t was created. The population of those surveyed consisted of 214 ge neral and specialty cont ractors involved with tilt-up construction throughout the United States. Contact infor mation for 94 contractors was acquired from the member direct ory of the TCA and 120 contractor s were identified through the directory of contractors who ha d attended the career fair host ed by the M.E. Rinker Sr., School of Building Construction at the University of Florida. The surveys were distributed to the contractors via an email attachment. The messa ge in the email explained the research being conducted, and directed those willing to participsa te to go to a webpage where the survey could be accessed and completed. Within three days 12 people had responded. A follow-up email was sent 3 days after the initial distribution of the survey. Survey recipients who did not respond

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36 to the first survey were asked to please res pond. Those who had responded were thanked for their assistance. Nine people responded to the second email message. Nine days after the first email message was sent a third and last email was sent to the potential re spondents. Four firms responded to the third and final request, resulting in a tota l of 25 respondents. Compilation of Survey Results and Checklist Development The survey responses were qualitatively exam in ed with particular focus on the responses to questions related to the primary tilt-up constr uction safety concerns and the perceived causes of accidents in the tilt-up construction industry. The information from the qualitative survey responses and the information colle cted through the literature revi ew were the primary resources utilized to develop a comprehensive checklist of tilt-up safety practices. Informal conversations were also conducted with two prime contractors to gather additional insights about tilt-up construction. The researcher was referred to the first contractor contact after the committee chair spoke with the contact at a social event s ponsored by the contacts company. The second contractor contacted the research er after the survey had been cl osed and the survey results had been analyzed. The researcher called the cont ractors contact to receive information about different strategies related to cran e positioning and panel casting locations. The comprehensive checklist was developed by first modifying the TCA checklist based on current information about tilt -up construction. The survey results were helpful in making refinements to the checklist. The comprehensiv e checklist was extensive and covered many of aspects of tilt-up construction, beginning with the design. A co mpact version of the checklist was also developed for use in the field. It co ntains only information relevant to safe field operations.

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37 CHAPTER 4 SURVEY RESULTS Company Demographics In all, 25 firm s responded to the survey on ti lt-up construction practices. While most of the surveys were completed in their entirety, a few respondents failed to answer some of the questions. The questions in the survey and th e corresponding number of valid responses are shown below. 1. Is your company a prime contractor, or a trade contractor (subcontractor )? (25 valid responses) 2. What is the approximate a nnual volume of construction wo rk performed by your company? (25 valid responses) 3. Does your company employ a full-time safety dire ctor, whose sole respons ibility is to monitor and address the firms safety concerns? (25 valid responses) 4. Does your company have a written safety policy? (25 valid responses) 5. Approximately how many projects are constr ucted each year by your company, which include the installation of tilt-up pa nels? (24 valid responses) 6. As an estimated percentage, how much of your companys busine ss relates to tilt-up construction? (24 valid responses) 7. Does your companys safety policy include provisi ons that are specific to tilt-up construction? (25 valid responses) 8. Of the company projects involving tilt-up constr uction, what is the range in size (in square feet) of these projects ? (24 valid responses) 9. What is the typical intended us e of the tilt-up projects that your company constructs? (check all that apply) (22 valid responses) 10. What is the typical size of crew that is utilized when setting tilt-up panels? (24 valid responses) 11. When setting tilt-up panels, does the signal person also assist with rigging or other tasks? (23 valid responses) 12. What is the standard procedure in your company when setting a tilt-up panel for when the crane is released? (23 valid responses) 13. Are any safety meetings/discussions held prior to the start of setting tilt-up panels? (24 valid responses) 14. Does your company have a policy regarding wind speeds when tilt-up panels will not be set? (20 valid responses) 15. How many accidents has your company (or subcontra ctors) experienced with regard to tilt-up construction? (24 valid responses) 16. What is your biggest safety concern when setting tilt-up panels ? (23 valid responses) 17. What do you feel is the major reason that other contractors have acciden ts when setting tiltup panels? (23 valid responses) 18. If an all inclusive tilt-up construction safety checklist was created in a format available to workers in the field, do you feel that it would be useful to reduce the number of accidents and deaths in tilt-up construction? (check all that apply) (22 valid responses)

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38 19. What do you feel are the most im portant tilt-up safety precauti ons and procedures that must be followed by all construction workers on tilt-up projects? (2 3 valid responses) 20. Does your company have any safety procedures/p ractices related to ti lt-up construction that you could share? (23 valid responses) Of the 25 survey respondents, 16 were prime contractors and nine we re subcontractors. The smallest firm that responded had an average annual income of nine million dollars, and the largest firm had an average annua l income of three billion dolla rs. The median annual income was $ 100 million, with ten respondents (Table 4-1) reporting annua l incomes in the range of $50 to 150 million. Table 4-1. Average annual income of survey respondents Respondent Average annual income $ 1 9,000,000 2 12,000,000 3 25,000,000 4 30,000,000 5 35,000,000 6 36,000,000 7 50,000,000 8 55,000,000 9 67,000,000 10 70,000,000 11 70,000,000 12 80,000,000 13 100,000,000 14 100,000,000 15 120,000,000 16 150,000,000 17 175,000,000 18 225,000,000 19 250,000,000 20 400,000,000 21 750,000,000 22 750,000,000 23 800,000,000 24 1,500,000,000 25 3,000,000,000

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39 General Safety Structure All (100%) of the responding firm s reported having a written sa fety policy. Eighteen firms confirmed that their safety policies included provis ions specific to tilt-u p construction. Of the 25 survey respondents, 16 firms (64%) employe d a full-time safety director whose sole responsibility was to monitor and ad dress the firms safety concerns. General Tilt-Up Information The num ber of tilt-up projects completed by each respondent ranged from zero to 80 projects per year. Table 4-2 shows the number of tilt-up projec ts completed annually by the survey respondents. One respondent reported an average of zero tiltup projects annually, this response was considered invalid. Table 4-2. Number of tilt-up projects completed by survey participants annually Average annual number of tilt-up projects Number of firms 0-9 8 10-20 7 21-40 3 Over 40 7 Tilt-up construction accounted fr om zero percent to 100 percent of the survey respondents estimated business volume. Table 4-3 illustrates the distributi on of responding firms economic reliance on tilt-up construction. One company reported that tilt-up cons truction accounted for zero percent of its estimated business volume. This response was considered invalid. Table 4-3. Tilt-up construction as a percen tage of responding firms overall business Percentage of business Number of firms 0-25% 9 26-50% 5 51-75% 5 76-100% 5

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40 Individual tilt-up constructi on projects completed by respondents ranged in area from 5,000 square feet to 1,750,000 square feet. The ty pes of tilt-up buildings built by the respondents are listed below, in no particular order: Warehouses (19 responses) Offices (20 responses) Light industrial buildin gs (14 responses) Schools / educational buildings (7 responses) Parking structures (2 responses) Dealerships (2 responses) Retail buildings (5 responses) Specialty buildings (1 response) Public facilities (1 response) Manufacturing facili ties (2 responses) Religious facilities (3 responses) Dormitories (1 response) Food and beverage processing (1 response) Prisons (1 response) Medical (1 response). Tilt-Up Safety Information The survey responses provided m any insights ab out the safety concer ns and practices of contractors involved with tilt-up construction. By receiving firsthand knowledge of the safety concerns and safety practices of tilt-up cont ractors, practical suggestions can emphasize the major components to be included in a tilt-up safety checklist. Accident History Respondents were asked how m any minor and major accidents their firm (or subcontractors) had experienced in regard to tilt-up construction. Of the twenty four respondents to this question, the summary of mi nor accidents included the following: Two in the last 5 years: lifting clutch fell on hand, and Burke bar slipped while moving panel and worker was struck on side and bruised Unsure, but a small amount Unsure Crane turn-table weld broke and the pa nel dropped, but there were no injuries

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41 Approximately 4 (muscle st rains, cut fingers, etc.) Four One to 2 per year One (2 replies) Zero (15 replies). When asked about the number of major acci dents their firm (or subcontractors) had experienced in regard to tilt-up construction, 23 respondents provided a reply. The responses regarding the number of major tilt-up accidents were as follows: Zero (18 replies) One (3 replies) Unsure (1 reply) One every three to five years (1 reply). Work Crew Participants in the survey were asked about the work crew used when setting tilt-up panels. One respondent gave an invalid re sponse to this question. Of th e rem aining 24 respondents, the number of crane operators typically used was as follows: One crane operator (16 replies) One crane operator and one de signated flagman (1 reply) One crane operator and one mechanic (1 reply) One to two crane operators (1 reply) Two crane operators (5 replies). For the number of additional crew members typi cally used when setting tilt-up panels the following responses were given: Three additional crew members (1 reply) Four additional crew members (3 replies) Five additional crew members (1 reply) Five to six additional crew members (2 replies) Five to seven additional cr ew members (2 replies) Five to eight additional crew members (1 reply) Six additional crew members (8 replies) Ten additional crew members (5 replies) Fifteen to 20 additional crew members (1 reply).

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42 It is important to know the number of workers ty pically involved in tilt-up operations. It is possible that each project will have a different crew size, depending on the dynamics of a tilt-up project. To ensure safety in tilt-up construction everyone must have a specific duty, and workers involved in the erection process should have experience and knowledge in the proper tilt-up procedures. Signalperson Duties Of the 23 survey particip ants who an swered question 11 regarding signalperson responsibilities, 65.2% said that the signalperson al so assisted with riggin g or other tasks. The remaining 34.8% noted that signaling was the only task assigned to the signalperson. The signalperson is the only line of communication to the crane operator, and is often also the rigging foreman, as the survey results sugges t. The clear designati on of responsibilities is imperative to maintaining safety in tilt-up construction. Crane Release Procedures Survey question 12 asked, What is the standa rd procedure in your company when setting a tilt-up panel for when the crane is released ? Respondents could choose from one of the following three answers: The crane is released when at least 2 braces have been installed (3 replies) The crane is released when all brace s have been installed (10 replies) The crane is released when the signa l person deems it safe (10 replies). In addition to choosing one of the above responses, seven respondents also chose the option of other. Additional answers, give n by survey participants, were as follows: Signalperson is responsible for all clear once all braces are secured All braces are installed and th e signal person deems it safe His (signalpersons) judgment is based on the companys polic ies and procedures Signalman is generally the erection foreman. After all braces are anchored to the slab or deadmen, the foreman signals the crane operator to ease off the load Signalperson normally signals the release of the crane when all braces are installed

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43 Erection foreman checks all connections before release The competent person on site has deemed the panel is secured and safe to release the crane. Releasing a panels rigging appa ratus from the crane is a pr ocedure that could lead to unnecessary accidents if proper preca utions are not taken. Through the survey results it can be seen that a majority of the tilt-up contractors re quire all bracing to be in stalled and/or permission from the signal person before a panel can be rele ased from the crane. Many contractors require both of the above actions, plus the checking of all bracing connec tions before a panel can be released from the crane. Safety Meetings When asked about safety m eetings before the tilt-up process begins, 95.8% of the respondents said that a safety meeting was held prior to the setting of pa nels on every project, and 4.2% said that a safety meeting was held on most projects. No resp ondents (0%) said that safety meetings were never held. It is impe rative for all involved in the tilt-up process to understand the planned procedures, safety practices, and individual worker responsibilities that will be put into place during the erection process. Wind Speed Policies Question 14 of the survey inquired about th e responding companies policies regarding erecting tilt-up panels in wi ndy conditions. Two respondents said that their com pany had no policy on wind speeds and tilt-up construction. Eight een said that the cr ane operator makes the decision of when the winds are t oo excessive to erect tilt-up panels However, of the respondents who answered the question, eight gave additional information as follows: Depends on the size and type and openings in the panel. A field decision is made when winds reach 20 mph Erection is shut down when the first of either occurs: cran e operator determination or winds greater than 19 mph

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44 Fifteen mph All crane operators are certifie d prior to working on job sites Fifteen to 20 mph Thirty five mph (2 replies) It is not just the operator; a group decision is made if the winds are above 15 to 20 mph. As case studies of tilt-up accidents can attest to, the risks presented by high winds should not be taken lightly when lifting tilt-up panels. It is imperative for contractors to have policies outlining when tilt-up operations will be suspe nded due to high winds. Workers must follow these policies in the field for their own safety, and the safety of their crew members. Contactor Safety Concerns Respondents gave valuable insights into the m ost serious safety concerns of actual tilt-up contractors. Respondents were as ked to give their biggest safe ty concern when setting tilt-up panels. Many respondents gave more than one sa fety concern. The responses given have been grouped together in terms of similarity. Each classification of safety concerns given by respondents, and the number of firms who menti oned each classification as a major concern is listed below. Struck by moving/falling panel, caught in /between type acci dents (6 replies) Failing to keep work zone (fall and pinc h zones) clear of unnecessary workers (5 replies) General safety of everyone involved (4 replies Horseplay/failure to stay al ert/complacency (3 replies) Crane failure (3 replies) Improper rigging (3 replies) Erection care/initial pick up of panel/failure of lifting devices (3 replies) High winds from tropical storms (1 reply). Views on Other Contractor Accidents Respondents were asked why they feel ot her contractors have experienced tilt-up acciden ts. The responses given have been groupe d together in terms of similarity. Each

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45 classification of accident causes, and the number of firms who mentioned each classification as a major reason for tilt-up accidents is listed below. Careless behavior/not paying attention (7 replies) Poor/inadequate trai ning (4 replies) Rushing/sacrificing safety for speed (4 replies) Inexperience (4 replies) Lack/absence of safety procedures (3 replies) Wrong rigging/miscalculating loads (3 replies) Lack of planning (2 replies) Improper crane selection (1 reply) Removing braces prematurely (1 reply) Cowboy mentality (1 reply) Not following/ignoring erecti on procedures (1 reply Failure to designate a no access zone for workers not directly involved in the erection process (1 reply) Erecting panels in the dark (1 reply). Important Safety Procedures Survey participants were also asked what safe ty procedures and practices they felt were the most im portant to be followed by all construc tion workers on tilt-up projects. The responses given have been grouped together in terms of simi larity. Each classificat ion of important safety procedures and the number of firms who mentioned each cla ssification is listed below. Keep all unauthorized/unnecessary personnel out of the erection and danger area (10 replies) Ensure workers have adequate knowledge/experience (4 replies) Employ a certified/well trained crane ope rator crane safety. (3 replies) Always remain alert (3 replies) Proper planning, precautions begin be fore construction (2 replies) Follow all safety procedures (2 replies) Be aware of bracing requ irements (2 replies) Proper rigging/check rigging (2 replies) Be aware of tilt-up work zone requirements (1 reply) Always have an exit plan (1 reply) Practice good housekeeping (1 reply) Practice proper lifting techniques (1 reply) Follow safety checklist for engineering (1 reply) Follow OSHA requirements (1 reply).

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46 Validation Survey participants were asked if the creation of an all inclusive ti lt-up construction safety checklist in a format available to workers in th e field would be useful to reduce the number of accidents and deaths in tilt-up c onstruction. Of the 22 contractor s who answered the question, all (100%) of the respondents said that the information would be usef ul to the construction industry, and 59.1% of respondents requested a copy of whatever was developed. Summary The survey responses have been an invaluab le tool for the creation of a com prehensive checklist for tilt-up construction. Through the survey, contractors gave their biggest safety concerns regarding tilt-up construc tion. Next, they stated the cause s of their safety concerns. A final survey question allowed the respondents to suggest safety procedures that they feel are imperative to address the causes of their tilt-up safety concerns. According to the survey results, the most wi despread concerns with tilt-up construction safety among tilt-up contractors are falling panels resulting in struck by or caught in/between accidents and failing to keep unauthorized and unnecessary workers out of the falling panel danger zone. Contractors who responded to the surv ey felt that the top caus es of tilt-up accidents are insufficient or improper training, inexperien ced work crews, hurrying or rushing during the tilt-up process, and careless behavior. To e liminate the causes and concerns with tilt-up construction safety, the majority of the survey pa rticipants agreed that all unauthorized personnel should be kept out of the danger area, all work ers should have adequate knowledge and training, all workers should remain alert at all times, and the crane oper ator should be certified and well trained.

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47 CHAPTER 5 CHECKLIST RESULTS Checklist Structure The checklist produced by the Tilt-U p Concre te Association, title d Safety Checklist for Concrete Tilt-Up Construction, constituted a us eful contribution to outlining safe work procedures for tilt-up construc tion. Upon closer examination, it was felt that the TCA checklist would be a valuable resource for the research, but that additional safety co ncerns needed to be included and that a reorganizati on of the information would be more appropriate. Information from other literature sources was also examined. These sources provided useful information, but in general were focused on only specific aspects of the tilt-up operating procedures and safety concerns. Thus, the content for the new checkli st was derived from the literature, the TCA safety checklist, the surv ey responses, and informal conversati ons with contractors involved in tilt-up construction. After this information had b een examined it was determined that the best way to organize the comprehensive safety check list was by chronological classifications. The comprehensive safety checklist was divided in to the following headings: Design of Tilt-Up Panels, Site Logistics Consider ations, Planning the Tilt-Up Seque nce, Pouring the Panels, Crane Set-Up and Operation, Job Conduct, Rigging the Panels, Preparing for Lifting, Lifting the Panels, Swinging the Panels, Positioning and Bracing the Panels, Releasing the Crane, and After Crane Release. Design of Tilt-Up Panels It is im perative on all tilt-up projects that each panel that is cast has been designed or approved by a professional engineer experienced in tilt-up cons truction. If the panels are designed by the tilt-up contractor, the shop drawin gs must still be reviewed and approved by the

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48 engineer of record. The safety checklist steps to follow during the design of tilt-up panels are as follows: Shop drawings should show the location of all rebar, inserts, embeds, openings, blockouts, conduits, and strongback s (if required by engineer). Ensure that all shop drawings are approved by a professional engine er experienced in concrete tilt-up panel construction. Ensure that the engineer has identified prope r lifting insert locations to avoid insert failure/pullout due to edge loadi ng, shear loading, or overloading Remember, stresses on lifting inserts shift dur ing the lifting process. Always follow the engineers plan for insert locations. Verify that the bracing manual includes br aces to withstand the proper wind loads and is approved by engineer Site Logistics Considerations Before a tilt-up project begins, the project drawings m ust be thoroughly examined, and a site visit must take place. Efficiency and safety on tilt-up projects begins with a precise understanding of the site elements at the project. Site logistics considerations include panel casting location(s), crane location( s) and pathways, and identifyi ng all hazards present on site such as overhead power lines, underground utilities, trees, trenches, soft sub grades, and uneven terrain. The literature was reviewed and informal conversations were conducted with tilt-up contractors. This provided the in formation that different project sites will demand different panel casting locations and crane locations. Panels can either be cast on the building slab, or on temporary casting slabs (also called casting beds) created solely fo r casting panels. Casting slabs may be integrated into the build ing slab or they may be remove d after all panels have been installed. The location of the crane is largely de termined by the shape of the building floor plan, the size of the floor plan, and the location where panels are cast. If the slab can support the crane, the crane can be positioned in the middle of the slab where it may reach all panels with minimal repositioning.

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49 If the slab is not capab le of supporting the crane, a section may be left out of the slab for the crane to maneuver. After the crane has finish ed its duties and is rem oved from the site, the void section of the slab wh ere the crane was located can be filled with concrete. Another way to locate the crane inside the buildings floor plan is to pour the slab after all tilt-up panels have been erected. In this situat ion panels are cast on te mporary casting slabs and then positioned on a strip footing at the perime ter of the building. Braces are attached to sacrificial footings (also called dead legs) instead of the building slab. Afte r all panels have been erected, the roof structure is tied in and the braces can be rem oved. The building slab is poured over the top of the sacrificial f ootings after bracing has been re moved. This option allows the building slab to be poured under a roof and a more controllable environment. A final way to position the crane is outside of the building perimeter. Positioning the crane outside of the building perimeter requires more movement of the crane. It also requires a considerable amount of fr ee space around the perimeter of the build ing. If this approach is taken, a clear, hazard-free path for the crane must be constructed, and all soils along the path must have adequate load-bearing capacities. Safety checkli st items to follow when considering the site logistics of a tilt-up project include the following: Become familiar with bu ilding layout and design. Visit the project site. Identify all possible hazards on site and de termine a way to eliminate the hazards. Hazards may include overhead power lines underground utilities, trees, trenches, soft sub grades, uneven terrain, low-lyi ng areas where rainwater can pond, etc. Determine where panels will be cast. o If panels are cast on the building slab ensure that the slab is strong enough to support a crane capable of lifting twice the weight of the heaviest panel. o If the panels are cast on the building slab cover all blockouts to prevent water from getting under the sl ab and weakening the subbase. o If panels are cast on a separate casting bed ensure that they are positioned to allow for minimal crane movement. o Verify that the slab can sustain the load of panels being cast. This is especially true when panels are stacked.

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50 Planning the Tilt-Up Sequence For tilt-up construction projects to run sm oothly and efficientl y, a detailed tilt-up sequence plan must be created. The plan should take into consideration the casting of all panels in positions where they can be lifted with smooth motions and easy access. The lifting process should follow a predetermined order that complime nts the cranes position, so it does not have to move often. A common method is to follow a cloc kwise rotation when setting tilt-up panels. A plan should be drawn out, which shows the layou t of all panels, how th e crane will reach each panel, and the order in which the panels will be erected. Everyone involved in the tilt-up process should be familiar with the tilt-up sequence before any lifting begins. The following points are the checklist items for Pla nning the Tilt-Up Sequence. Notify all subcontractors of the planned pane l erection dates in the project schedule. The tilt-up erection crew should be the onl y subcontractor allowed on site when panels are being erected. Before the project begins, acquire si gned notices from all subcontractors acknowledging that only the er ection subcontractor is allo wed on site when panels are being erected. Provide a plan drawing that shows: o all tilt-up panels in their casting locations. o how each panel will be reached by the crane(s). o the order in which the panels will be lifted. When creating the tilt-up sequence, follo w a logical order that can be easily remembered by those involved in the tilt-up process. Hold a meeting to familiarize all worker s with the tilt-up sequence before any rigging or lifting begins. Pouring the Panels The saf ety of the tilt-up process is largely dependent on the initial construction of the concrete tilt-up panels. Tilt-up panels must be poured in compliance with the engineers approved shop drawings. Weak or improperly poured panels are more likely to fail during the erection process than properly poured panels. Afte r all blockouts and inse rts are installed, they

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51 must be monitored to ensure that they are not accidentally moved while the concrete is being poured. When pouring concrete tilt-up panels, consider the following sa fety checklist steps: Verify that the subbase under the casti ng platform is compacted and level. Test the bond breaker to ensure that it functions properly be fore pouring panels. Make sure the concrete is properly cons olidated around all inserts and reinforcing. When screeding or finishing the panel, ma ke sure that inserts are not bumped or accidentally moved. Cover all blockouts to prevent water from getting under the panel. Crane Set-Up and Operation A crane is the workhorse of the tilt-up process. It is im perative that the crane chosen for a tilt-up project is capable of lifting the heaviest pane l on the project, plus a ll rigging used to attach the panel to the crane. A good rule is to choose a crane capable of lifting twice the weight of the heaviest panel. This selection must take into consideration the load imparted by the panel when it is swung laterally over the outriggers. This will help ensure th e safety of all tilt-up erection crew members. Cranes should always be set up on a slab or section of the ground that has a load bearing capacity capable of supporting the crane and all loads that it may carry. If possible, the crane should be located in a position where it will be ab le to reach all tilt-up panels without having to overextend the boom of the crane. If it is impossi ble for the crane to reach all panels from one location, the crane should be moved the minimum am ount of times to allow it to reach all panels. Locate the crane away from all overhead obstacles, especially power lines. When the location of the crane is determined and the crane is positio ned, all outriggers should be fully extended. The outriggers should bear on large pa d areas to spread the load on th e ground. If the crane is located on the slab, dunnage should be placed under all loca tions where the crane is in contact with the slab. The crane operator must be certified and ex perienced in tilt-up constr uction. All pre tilt-up safety meetings should be attended by the crane operator. The crane operator and the erection

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52 crews signal person must understand the hand sign als that will be used to communicate while lifting and setting tilt-up panels. While some si gnals may be communicated via two-way radios, hand signals may be required in some instances. Safety considerations related to crane setup included in the tilt-up safety checklist are as follows: Choose a crane capable of lif ting twice the weight of th e heaviest concrete tilt-up panel plus the weight of all rigging gear. Considerations should also be given to boom travel distances. Never allow the crane operator to carry a panel while the crane is mobile. Verify all crane and insurance cert ification is valid and up to date. Hire a third party inspector to inspect a ny crane that was assembled on-site. This typically includes tower cranes and lattice boom cranes among othe r types of cranes. Conduct third party compaction tests on all surfaces where the crane may be located to verify that the load bearing capacities of the surfaces are ca pable of supporting the crane (includes slab and/or ground). Locate the crane in a position that is clear of all overhead obstacles and power lines, uneven or rough terrain, and soft subgrade. Choose crane locations where the maximum amount of panels will be able to be lifted with the minimal amount of crane moves. Never overextend the boom. Fully extend all outriggers and place pads under all outri ggers to properly distribute the load transferred by the crane to the ground or slab surface. If the crane is located on th e slab, the slab must be pr operly designed to support the load of the crane and the panels and rigging that the crane will lift. Do not allow a crane to be positioned on any part of a sl ab that is not designed to support it. If the crane is located on the slab, use dunnage on all locations where the crane and slab are in contact to dist ribute the pressure exerted onto the slab. Use the same practice when positioning the crane on the ground. If the crane is to be located on the sla b, do not allow the cran es weight to be transferred to the edges of the slab. Provide an exit and entrance ramp to the slab for the crane. Employ a certified crane operator with consider able experience with concrete tilt-up panels. Verify that the crane operator and signal person know the same hand signals that will be used to communicate during th e lifting and setting of panels. Job Conduct According to tilt-up contractors who responded to the survey, one of the m ajor causes of tilt-up accidents is misconduct by workers. Misconduct includes horseplay, unnecessary talking, wandering in the danger zone, carelessness, becomi ng too comfortable with the lifting process,

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53 and the failure to stay on guard at all times. Only workers ex perienced in tilt-up construction, who have demonstrated a track r ecord of awareness and attention to safety should be allowed to be a part of the erection crew. The following safety checklist items re late to job conduct. Always exhibit a professional and atten tive conduct while setting the panels. Everyone involved in the tilt-up process should: o Only talk if absolutely necessary. o Stay out of the danger zone, an area e qual to twice the he ight of the panel being lifted, unless dire ctly involved with the task currently being conducted. o Remain focused on the designated responsibilities. o Constantly stay aware of all possible dangers. o Never become lackadaisical or complacent. o Remain on guard at all times. Wear proper attire at all times including a hardhat, boots, gloves, long pants, and full sleeve shirts. Rigging the Panels A secure co nnection between the crane and th e concrete tilt-up pa nel being lifted is imperative to the safety of the tilt-up crew. If the rigging fails, or cau ses the panel to break, every crew members life is in danger. Rigging systems should be approved by the engineer of record, along with the lo cation of the lifting inserts. To lim it the amount of time workers are in danger of an unsecured panel, braces should also be attached to the panel when the rigging is attached. An experienced rigger foreman should be the only individual allowed to rig the panel to the crane. When rigging panels for lifting, consider the following: Before rigging begins, verify that all lifti ng inserts and bracing inserts are in the proper locations as identified by the engineer of record. Insert locations should be verified by a competent person not involved with the initial placi ng of inserts when the panel was poured. Allow only an experienced rigger foreman to attach the cranes rigging to the tilt-up panel. Follow the rigging details exactly as specified by the engineer of record. If inserts appear too close to a pane l edge, consult with the engineer before rigging. Check the condition of the spreader bar. If it appears warped or worn, replace it. Check the condition of all rigging hardware. Ma ke sure that the hardware is new. If it is reusable, make sure that it is in like new condition.

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54 Never use shorter cables than those specified by the engineer of record. This will redistribute the load and may ove rload inserts and crack panels. Never weld a lifting insert; this may cause the insert to fail. Attach bracing according to the manufactur ers bracing manual and the engineers specifications. If strongbacks are required per the engineer verify that they are installed as specified. Any vertical secti on of concrete that is less than 2-0 wide will usually require a strongback. Preparing for Lifting Before lifting can begin, proper preparations m ust be made. The following procedures should be followed before lifting concrete tilt-up panels. Conduct a mandatory safety meeting to be attended by all workers involved in the panel erection process. Distribute the comprehensive checklist to all workers and have them sign it at the conclusion of the safety meeting. A minimum erection crew should incl ude: one crane operator, one rigger foreman/signalperson, two workers to guide the panel, and two workers to carry the ends of the bracing and attach them to the slab. Verify the crane is in proper wo rking order before lifting begins. Give the crane operator a copy of all panel weights and a copy of the panel erection sequence. Double check that all rigging is c onnected as specified by the erection manual/engineer specifications prior to allowing any lifting to begin. Ensure that all lifting hardware is conn ected properly. If using a bolt type connection, verify that the male insert is inserted to the proper bearing distance as specified by the insert manufacturer/engineer. Verify that the rigging will not trap the brac ing when the panel is lifted to its vertical location. If the bracing is trapped by th e rigging the bracing will not be able to extend away from the panel for installation. Verify that the concrete has attained the proper strength prior to lifting. Remove all obstacles and tripping hazards fr om the area where the lift occurs. This includes tools, electrical cords, gang boxes, etc. Broom sweep the area where the lift will occur. Remove all standing water (under and ar ound the panel) to eliminate unwanted suction loads. Demonstrate to workers the proper instal lation and use of lifting hardware, bracing, and all tools and equipment that will be used during the lift. Check the condition of all tools that will be used during the erection process. Instruct workers to ne ver reach under a panel. Flag the cranes swing radius, and limit access within this area to only the panel erection crew members necessary for the current operation.

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55 Lifting the Panels The greatest stres ses are put on a panels lifting inserts when the panel is being lifted off of the ground to a vertical position. It is imperative that only the crew members involved with the lift are allowed in the danger zone, and those cr ew members must remain on their guard at all times. The following safety procedures should be followed when lifting a c oncrete tilt-up panel. Workers should never position themselves: o Under a panel o On the blind side of a panel from the crane o Between the crane and a panel o Between two panels o Out of the crane operators view Only allow workers directly involved with the task currently be ing conducted to be in the danger zone, an area equal to tw ice the height of th e panel being lifted. Outfit the signal person in a brightly colored vest or shirt. Verify that the crane operator and signal person understand the hand signals that will be used to communicate during th e lifting and setting of panels. Watch for panels that are stuck to th e casting slab, thereby causing dangerous stresses. Do not use too much force when using pry bars at the extreme edges of a panel to release it from the slab. This may cau se the panel to crack and become weak. Do not lift panels if winds exceed 20 mph. If a panel has special shapes, rigging, or blockouts, take extra precautions when lifting. As the crane lifts the panel the rigger foreman/signal pers on should look up to ensure that all cables are straight and do not get caught on inserts or other hardware. If a cable begins to twist or gets caught, its strength decreases. The panel must then be lowered so that the problem may be resolved. Hold the end of the braces to preven t damage to the slab or the braces. Remain aware at all times of how the panel is moving. Swinging the Panels After the panel is lifted to a vertical position, the crane will sw ing it to the position where it will be s et. Some panels will only need to be swung a short distance, but safety hazards still exist. Some of the same safety precautions recommended for lifting the panel should also be adhered to for swinging the panel.

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56 Workers should never position themselves: o Under a panel o On the blind side of a panel from the crane o Between the crane and a panel o Between two panels o Out of the crane operators view All workers involved in swinging the panel s hould be weary of any trip hazards that were not removed prior to rigging the panel. Never position any part of ones body between the panel being lifted and the ground, or the panel being lifted and an adjacent panel. Hold the end of the braces to preven t damage to the slab or the braces. Positioning and Bracing of Panels Once the tilt-up panel has been swung to the general area where it will be perm anently positioned, the crane will lower the panel to the st rip footing and it will be plumbed and braced. Safety hazards still exist while the panel is be ing positioned, and the following safety procedures should be followed. Workers should never position themselves: o Under a panel o On the blind side of a panel from the crane o Between the crane and a panel o Between two panels o Out of the crane operators view Plumb and level the panel while the crane is still attached. If bracing for a particular panel cannot be installed with the crane still attached to the panel, always finish the bracing of that panel before the next panel is lifted. Use the minimum number of worker s possible to plumb the panel. Always move slowly, delibe rately, and cautiously when a panel is being moved in the vicinity of a previously erected panel. Make sure that the panel be ing lifted does not strike an adjacent panel that has already been braced. Always have an exit plan in case a panel collapses. Panels should be as plumb as possible befo re attaching bracing to the slab. This limits the likelihood that braces will need to be loosened later to finish plumbing the panel after the crane has been released. Releasing the Crane All persons involved with the tilt-up process should exercise special caution when the crane is released. The following saf ety procedur es should be followed when releasing the crane:

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57 Always use proper fall protection precautio ns if workers must reach an elevated position to release the crane. Check all bracing connections before releasing the crane. Check the condition of the braci ng before releasing the crane. Do not release the crane if the br acing appears weak or inadequate. Place shims in the proper locations under the panel as identified by the engineer before grout is installed. Verify that the panel is plumb prior to releasing the crane. This is especially important if the panel is going to support an adjacent spandrel or lintel panel. Verify that the panel is plumb prior to releasing the crane if the bracing design requires a subsupport system of knee, lateral, end, or cross bracing. Only the workers actually releasing the crane from the panel, after bracing has been attached, should be nearer to the panel th an a distance of twic e the height of the panel. When releasing the crane, do so slowl y. Watch for unusual movements in the bracing or the panel. After Crane Release Safety precautions should be followed well af ter the crane is releas ed. Even after all panels have been erected and pr operly braced, safety hazards still exist. Practice the following safety procedures to ensure a safe tilt-up project after tiltup panels have been erected and braced. Make sure ALL bracing has been properly atta ched to all panels before the end of the work day. Check all bracing at least three times per day (at the beginning of the day, in the middle of the day, and at the end of the day). In addition, check all bracing in the event that there is a wind shift. Grout under all panels before the end of the work day. Always remain cautious around te mporarily braced tilt-up panels. Stay out of the danger zone if winds exceed the stated bracing wind load capacity. When pouring the pour back strip, do not exert excessive pressure on the braced panels. Do not remove any bracing until the panels have been properly integrated into the roof structure and the pour back strip has been installed. This work should be expedited to minimize the time that the pa nels are supported solely by the braces. Check with the engineer before removing bracing.

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58 Field Safety Checklist A m ulti-page safety checklist for tilt-up construction would be too cumbersome to use effectively in the field. In fact, some aspects of the checklist would be deemed irrelevant by field workers. To add field relevancy to the compre hensive safety checklist, a compact version was created for use in the field. The compact checklis t contains only information pertaining to field operations beginning with lifting th e panels. The information c ontained in the field safety checklist is listed below. Lifting the Panels Workers should never position them selves: o Under a panel o On the blind side of a panel from the crane o Between the crane and a panel o Between two panels o Out of the crane operators view Only allow workers directly involved with the task currently be ing conducted to be in the danger zone, an area equal to tw ice the height of th e panel being lifted. Outfit the signal person in a brightly colored vest or shirt. Verify that the crane operator and signal person understand the hand signals that will be used to communicate during th e lifting and setting of panels. Watch for panels that are stuck to th e casting slab, thereby causing dangerous stresses. Do not use too much force when using pry bars at the extreme edges of a panel to release it from the slab. This may cau se the panel to crack and become weak. Do not lift panels if winds exceed 20 mph. If a panel has special shapes, rigging, or blockouts, take extr a precautions when lifting. As the crane lifts the panel the rigger foreman/signal pers on should look up to ensure that all cables are straight and do not get caught on inserts or other hardware. If a cable begins to twist or gets caught, its st rength decreases. The panel must then be lowered so that the problem may be resolved. Hold the end of the braces to preven t damage to the slab or the braces. Remain aware at all times of how the panel is moving. Swinging the Panels Workers should never position them selves: o Under a panel o On the blind side of a panel from the crane

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59 o Between the crane and a panel o Between two panels o Out of the crane operators view All workers involved in swinging the panel s hould be weary of any trip hazards that were not removed prior to rigging the panel. Never position any part of ones body between the panel being lifted and the ground, or the panel being lifted and an adjacent panel. Hold the end of the braces to preven t damage to the slab or the braces. Positioning and Bracing of Panels Workers should never position them selves: o Under a panel o On the blind side of a panel from the crane o Between the crane and a panel o Between two panels o Out of the crane operators view Plumb and level the panel while the crane is still attached. If bracing for a particular panel cannot be installed with the crane still attached to the panel, always finish the bracing of that panel before the next panel is lifted. Use the minimum number of worker s possible to plumb the panel. Make sure that the panel be ing lifted does not strike an adjacent panel that has already been braced. Always have an exit plan in case a panel collapses. Panels should be as plumb as possible befo re attaching bracing to the slab. This limits the likelihood that braces will need to be loosened later to finish plumbing the panel after the crane has been released. Releasing the Crane Always use proper fall protection precautio n s if workers must reach an elevated position to release the crane. Check all bracing connections before releasing the crane. Check the condition of the braci ng before releasing the crane. Do not release the crane if the br acing appears weak or inadequate. Place shims in the proper locations under the panel as identified by the engineer before grout is installed. Verify that the panel is plumb prior to releasing the crane. This is especially important if the panel is going to support an adjacent spandrel or lintel panel. Verify that the panel is plumb prior to releasing the crane if the bracing design requires a subsupport system of knee, lateral, end, or cross bracing. Only the workers actually releasing the crane from the panel, after bracing has been attached, should be nearer to the panel th an a distance of twic e the height of the panel. When releasing the crane, do so slowl y. Watch for unusual movements in the bracing or the panel.

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60 CHAPTER 6 CONCLUSION Af ter analyzing the literature on tilt-up safet y, the results of the survey, and the comments from informal conversations with tilt-up contractors, it is obvious that safety plays a leading role in the tilt-up process. The consequences of a ti lt-up accident are often catastrophic. As a result, the efforts expended on tilt-up safety by everyon e involved in tilt-up construction should be substantial. As in all types of construction, e ach tilt-up project is uni que. A similar building may already have been built, but each individual project has site characteristics that determine the logistics of the tilt-up process that are unique to each project. Although project size, site conditions, crane location(s), pane l casting location(s), and the bu ilding design may change from project to project, the same safety concerns and procedures should be appl ied to every project. Similar dangers will present themselves on ever y tilt-up project. This is because multi-ton concrete panels are invariably being lifted in to the air by a crane and then temporarily braced until the roof structure and pour back strip are installed. If the co rrect safety procedures are not followed throughout every step of the tilt-up pro cess, the chances of an accident occurring increase. Fortunately, in term s of safety, the tilt-up process can be consistently followed on every project. This researcher believes that the safety check lists created as a result of this research successfully provides additional insight into tilt-up safety procedures and at-risk behaviors that were absent from the previously-developed Ti lt-Up Concrete Association checklist and the existing literature on tilt-up safet y. At-risk behaviors in tilt-up construction are those behaviors and actions that appear to put workers in danger. Allowing the signa l person to have duties besides rigging a panel to the cr ane before lifting begins and signa ling to the crane operator after lifting starts, puts workers in an advanced state of danger. After the crane is properly rigged, the

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61 signal persons sole duty should be signaling to the crane operator. Releasing the crane before all braces are installed is another at-risk behavi or in tilt-up construc tion, and should never be permitted. Setting tilt-up panels when winds exceed 20 miles per hour is an at-risk behavior. Although concrete panels weigh multiple tons, a relatively light wind will cause a panel to sway when it is being lifted by the crane. This crea tes a dangerous at-risk c ondition. When the panel is being maneuvered by the crane, there is an at-ri sk behavior if a worker is positioned out of view of the crane operator. The contents of the comprehensive safety checklist and the field safety checklist address the precautions that should be taken to avoid at-risk behaviors. If the recommendations for tilt-up safety provided as a result of this re search are used on every tilt-up project, construction workers will become and remain more aware of the dangers involved in tiltup construction. The increased awareness to tilt-up dangers and knowle dge of preventative safety procedures should help prevent the oc currence of injuries and deaths in tilt-up construction. The results of the survey revealed that there is a definite need for a field-friendly tilt-up safety checklist. Survey participants were aske d if the creation of an inclusive, comprehensive tilt-up construction safety checklist (in a format ava ilable to workers in the field) would be useful to reduce the number of accidents and deaths in t ilt-up construction. Of those who answered the question, all (100%) of respondents sa id that the information would be useful to the construction industry, and 59.1% of the respondent s requested a copy of this in formation. The all inclusive safety checklist created by this research includ es safety information that extends beyond the actual tilt-up process th at occurs in the field. The lengt h of the inclusive, comprehensive checklist is incompatible with conditions and time constraints that exist in the field. The field safety checklist, condensed from the comprehensiv e checklist that was developed as a result of

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62 this research, contains only safe ty recommendations that are to be followed for the period of time from the lifting of a panel to the release of th e crane. Field workers need a format of the checklist that is brief enough to be read during the tiltup process, yet still contains all pertinent safety information. It is believed that the field safe ty checklist created as a result of this research contains the information that is imperative for fi eld workers to review. Although the field safety checklist is lengthier than this researcher desired, compacting the checklist even further would result in the removal of vital safety information. If this researcher were to conduct the same study again without restrictions of time or money he would follow the same general procedures to reach the objective of the study. An additional step would be to visit and observe the erection procedures of different tilt-up contractors. When visiting these tilt-up projects, informal discu ssions would be held to address safety issues that they had experienced in their careers. It woul d be beneficial to conduct more personal conversations with contractors than wa s experienced during this study. While visiting tilt-up jobsites observations would be made to de termine if the contractors followed their own safety procedures, and the safety pr ocedures recomme nded by this study.

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63 CHAPTER 7 RECOMMENDATIONS To the construction industry it is recomm ended to review the comprehensive safety checklist and field safety checklist, become famili ar with their contents, and seriously consider how they can be incorporated into use. Th e comprehensive checklist should be posted in contractor jobsite trailers reviewed at safety meetings, and di stributed to the ar chitect, engineer, and all subcontractors on site before the tiltup panels are permanently integrated into the building. The field safety checklis t should be distributed to thos e field workers on site involved in the lifting of panels, setting panels, and releasing the crane. To future researchers it is recommended that research be conducted to determine how the information resulting from this research can best be presented to field workers. Recommendations for possible form ats include a laminated checklist with erasable marker, an adhesive backed checklist to atta ch to panels, a graphical representation of the checklist, and a pocket-sized checklist. Accommoda tions should also be made for non-English speaking workers when considering the format of the field safety checklist. To academic institutions with construction programs, it is recommended that the process of safely erecting tilt-up panels be incorporated as a teaching module in both a construction techniques class and a constructi on safety class. Tilt-up constr uction is increasing in popularity, and it is important for all st udents studying construction to have, at a minimum, a basic understanding of the steps involved in a tilt-up project, and the sa fety precautions that must be followed. For the teaching module on tilt-up safet y, the safety checklist should be taught and distributed to all students to lear n and use on their future jobsites

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64 LIST OF REFERENCES Barreneche, R. A. (1995). Tilt-up concrete on the rise. (on-site conc rete construction). Architecture 84(9), 161-167. Baty, J. (2007). Safety and the growing til t-up industry: advice for pros and novices. Concrete Construction 52(1), 44-46. Baty, J. (2008). Tilt-up safety inherent when planned. Tilt-Up Today 15(4), 36, 38-39, 41. Baty, J. (2008). Tilt-up: shaky ground. Concrete Construction 53 (7), 74-75. Bracker, R. (2008). Tilt-up trends up: use of this m ethod in the southeast continues to expand. Southeast Construction 8(7), 37. Collins, F. T. (1963). Design of tilt-up buildings, 2nd Ed., Know-How Publications, Berkeley, California. Dayton Superior (2007). Tilt-up construction product handbook, Dayton, Ohio. Hamilton, K. (2008). Working around cranes. Concrete Construction 53(7), 90. Hanley-Wood, Inc. (2003). Lessons for life (safety report). Concrete Construction 48(3), 34. Johnson, M. (2002). Tilt-up pioneer: Robert Ai ken developed tilt-up co nstruction nearly 100 years ago. Concrete Construction 47(8), 37-38. Kelly, D. L. (1990). Rigging for tilt-up: how to use the crane safely and efficiently. Concrete Construction 35(7), 863-866. MacKinnon, J. (2008). Shall we tilt? Concrete Construction 53(1), 69-70, 72, 74. Meadow Burke (2007). Meadow burke tilt-up manual Tampa, Florida. OSHA (2003). Tilt-up pa nel construction hazard. Safety and health in formation bulletins SHIB 10-15-03. Portland Cement Association (1973). Tilt-up concrete buildings: a value decision, Skokie, Illinois. Reed Business Information (2007). A tilt-up construction primer. Midwest Contractor 107(18), 10. Reed Business Information (2006). Tilt-up concre te association reports record sales in 2005. Construction News 73(12), 22. Ruhnke, J.,and Schexnayder, C. J. (2002). Descr iption of tilt-up concrete wall construction. Practice Periodical on Structural Design and Construction 7(3), 103-110.

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65 Sauter, E. (2008). Raising the stakes: tilt-up co ncrete construction gains market share based on ease of use and ability to sa ve owners time and money. Construction Today. 6(1), 10-11. Tilt-Up Concrete Association. Safety checklist for c oncrete tilt-up construction Mount Vernon, Iowa. Wood, D. (2007). New university and town makes for unique project for contractor team; one mans vision for a new university and town near immokalee, fla., leads to unique construction opportunities. Southeast Construction 7(6), 56.

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66 BIOGRAPHICAL SKETCH Jacob Vickers was born and raised in Orla ndo, Florida, where he graduated from the Center for International Studies at Dr. Phillips High School in 2003. Upon high school graduation he attended the University of Central Florida for his first two semesters of college before transferring to the University of Fl orida. In December 2006, Jacob was awarded a Bachelor of Arts degree in hist ory from the University of Florida. He officially began graduate studies at the University of Floridas M.E. Rinker Sr., School of Building Construction in January 2007, and is expected to graduate with a Master of Science in Building Construction degree in December 2008. After graduation, Ja cob plans to live in Florida under the employment of a construction management firm.