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!-- lncreasing Efficiency with Prefabrication in the Construction Industry ( Mixed Material ) --
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mods:abstract lang en Efficient practices in the construction of buildings and structures are sought after by all in the capital facilities delivery industry, including but not limited to owners, engineers, architects and contractors alike. As the construction industry seeks to move towards greener and more sustainable practices, along with it comes the desire for positive impacts on cost, project schedule, and waste reduction among other factors. This report provides an overview of the innovative method of prefabrication in construction, a technique that is underutilized in the construction industry despite its potential uses of increasing industry efficiency. As time and project schedule begin to emerge as the dominating factor, prefabrication is able to provide the most time-efficient solution. The concept of modularization has been present in the form of residential applications for centuries, and is now beginning to be explored for commercial application. As design presently moves towards strictly digital applications through Building Information Modeling (BIM) technologies, commercial modularization through use of off-site prefabrication is becoming a more viable option. Prefabrication through modularization provides many benefits to all major parties involved in the building process by providing a more controlled and safe environment, organized quality control processes, a more sustainable procedure through elimination of waste, and a flexible project schedule that should be considered when deciding the best method of construction in the commercial setting.
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mods:note Undergraduate Honors Thesis -Construction Management
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Increasing Efficiency with Prefabrication in the Construction Industry Objective To research and preview the use of modularization in commercial construction in the past, as well as its practicality in the future. Abstract Efficient practices in the construction of buildings and structures are sought after by all in the capital facilities delivery industry, including but not limited to owners, engineers, architects and contractors alike. As the construction industry seeks to move towards greener and m ore sustainable practices, along with it comes the desire for positive impacts on cost, project sche dule, and waste reduction among other factors. This report provides an overview of the innovative method of prefabrication in construction, a technique that is underutilized in the construction industry despite its potential uses of increasing industry efficiency. As time and project schedule begin to emerge as the dominating factor, prefabrication is able to provide the most time efficient solution. The conc ept of modularization has been present in the form of residential applications for centuries, and is now beginning to be explored for commercial application. As design presently moves towards strictly digital applications through Building Information Model ing (BIM) technologies, commercial modularization through use of off site prefabrication is becoming a more viable option. Prefabrication through modularization provides many benefits to all major parties involved in the building process by providing a mo re controlled and safe environment, organized quality control processes, a more sustainable procedure through elimination of waste, and a flexible project schedule that should be considered when deciding the best method of construction in the commercial se tting.
Introduction around for millennia and will continue to be the industry that shapes the tangible environment made up of buildings and infrastructure. It has however, been one of the sl owest industries to become more productive in the sense of economical and time factors 1 , even as material, equipment and software technology continue to evolve at a growing rate . As a result of the inability of the industry to conform to these new technolo gies at the rate they are being produced, productivity and operational efficiency in the field of commercial construction has fallen victim to factors present when erecting structures on site 2 . This can put a project at the mercy of code requirements and w eather inconsistencies, as well as noise complaints and site access issues to name a few . These subjects among other things can almost be eliminated by the use of another age old industry that is being severely underutilized for the benefits it provides, e ven though it is being applied more commonly in the industry now than it was years. Prefabrication through the use of manufacturing in an off site capacity has been considered as a method of construction that is not only recommended , but critical for enhan ced productivity and provides several other benefits 3 . Prefabrication helps to simplify construction processes within a controlled factory environment by using manufacturing techniques such as the assembly line improved by the use of building information modeling (BIM) , which creates precise templates for construction that ultimately reduces waste during production . These benefits all work to reduce overall construction costs, abbreviate building timelines, and improve working conditions that decrease risk of injury 4 . It is also important to note that while there may be some substantial benefits to producing building components 1 the AEC Industries in the United States for On Site and Off Journal of Construction Engineering and Management , 134(7), 517 526. 2 nalysis of the Growth Dynamics and Structure of the Modular Building Proceedings, Construction Research Congress , ASCE, Atlanta, GA., 1977 1986. 3 Li, Z., Shen, G. Q. P., Ji, C., and Hong, J. (2014). Based Analysis of Drivers and Constraints in the Use of Off Proceedings, International Conference on Construction and Real Estate Management, ASCE, Kunming, China, 26 36. 4 Site Construction Journal of Architectural Engineering , 19(1), 51 57.
within the confines of a shop setting, there are also some elements that may affect the capacity at which a project uses prefabrica tion. These factors include the necessity for precise plans due to difficulties in altering the design of a prefabricated building, the shippin g schedules and delivery loads , and the location of the building geographically 5 . Methods of Off Site Productio n Prefabrication Prefabrication is defined by the Merriam Webster dictionary as the fabrication of parts in a shop 6 . This is the broadest term for preassembling con struction components that come together as a whole in the factory off site , and are then shipped to the site. Prefabricated elements are also referred to as preassembled parts, and are usually on the smaller side 7 so shipping and delivery is manageable, ho wever there are instances where larger pieces are factory built. Precast Concrete 8 , and precast concrete is just that; concrete that is placed, reinforced, cured and finished in the factory before being shipped to the site to be put into place. Concrete prepared in this way offers a greater level of fire resistance and sound attenuation 9 , while also having the opportunity to have a decorative finish perfected off site. Precast concrete also c an be formed while foundation systems are being installed, so the installation process of 5 Site Journal of Architectural Engineering , 19(1), 51 57. 6 Merriam Merriam Webster , Merriam Webster, (Feb. 19, 2016). 7 57. 8 Merriam Merriam Webster , Merriam Webster, (Feb. 19, 2016). 9 PCA , Portland Cement Association (PCA), < http://www.cement.org/cement conc rete basics/products/precast concrete > (Feb. 13, 2016).
entire wall and elevated slab structures can be mass produced simplified by crane erection. The site placed concrete slows the construction process due to formwork as sembly and curing times before more concrete components can be placed, with the possibility of delays due to weather conditions and traffic impeding concrete trucks. Modularization Modularization is the act of building complete volumetric units the size o f r ooms that are fully fitted with finishes, furnishings, and mechanical, electrical and plumbing connections 10 . The use of this form of off site construction is most commonly used for hotel and apartment construction, as pre built rooms provide convenient building blocks for the formation of the structure. Modules in a multi story building are all pre designed to interlock together through an engineered system and created to surround a stabil ized core system made up of steel and/or concrete elements. Depending on the design, these module pods have the opportunity to be identical in nature or have variations that have a set place in the multi story structure, i.e. corner supported modules that have different structural elements as well as architectural design elemen ts 11 . W hen installed on site , the conformation of the individual modules is designed to be a permanent structure placed on a foundation system 12 , but with the potential to be disassemb led, i.e. if damage is sustained to the building for any reason. Building modularly shares a number of benefits that the other forms of prefabrication do, but one that is unique to the method is doubly insulated floors, walls, and ceiling systems. Since ea ch room is its own unit, 10 Lawson, R. M., Ogden, R. G., and Bergin, R. (2011). Rise Journal of Architectural Engineering , 18(2), 148 154. 11 lar Construction in High 154 12 Site Journal of Architectural Engineering , 19(1), 51 57.
when they are stacked adjacent to other units, it forms a dual barrier between rooms providing an extra sound barrier , better fire resistance and better temperature control from the two layers of insulation 13 . Industry Productivity and Efficiency Aggregate productivity gains in the construction industry have been studied for decades, and 14 , there is a statistic that claims the reason for it 15 . Other studies suggest that productivity has risen due to wage reductions and deskilling of the subcontractor trades 16 . However, p roductivity increases as a result of those factors do not propose a solution to continually aid in the increase of industry efficiency, and for as long as there is physical labor involved with the creation of structures, human error will exist and ultimately be responsible for setbacks. The practice that seems to provide t he most promise and opportunities to provide gains in productivity is the use of prefabrication through manufacturing off site 17 . Prefabrication in the shop setting has the potential to provide a level of quality control that cannot be attained by working o n site, especially with the technologies that have been and continue to be developed. Precision, speed and volume are the three key areas that prefabrication aids the necessity for productivity; once a template is designed and engineered to the desired fin al product, it can be entered into an automated system where components are cut to size and either assembled by the use of robotics or skilled laborers, quickly and systematically. While prefabrication is being used for a select number of construction acti vities currently, it has been 13 Lawson, R. M., Ogden, R. G., and Bergin, R. (2011). Rise Journal of Architectural Engineering , 18(2), 148 154. 14 in the AEC Industries in the United States for On Site and Off Journal of Construction Engineering and Management , 134(7), 517 526. 15 Growth Dynamics and Structure of the Modular Building Construction Indus Proceedings, Construction Research Congress , ASCE, Atlanta, GA., 1977 1986. 16 Eastman , the United States for On Site and Off 517 526 17 Li, Z., Shen, G. Q. P., Ji, C., and Hong, J. (201 4). Based Analysis of Drivers and Constraints in the Use of Off Proceedings, International Conference on Construction and Real Estate Management, ASCE, Kunming, China, 26 36.
found that segregating certain building activities into on site and off site responsibilities has eliminated the ability to arrange for more construction to be completed off site and more assembly co mpleted on site 18 . Reliance on Technology and Building Information Modeling (BIM) Along with the desire to move the industry to become more productive in its ability to produce final products at a faster pace, there comes a need for a vehicle to provide accurate plans and specifications not only to create a clash proof system regarding measurements and materials , but also because of the difficulties that exist in altering the design of a prefabricated building . Three dimensional (3 D) models produced by building information modeling (BIM) can provide these capabilities in a way that two dimensional (2 D) drawings cannot. BIM models have the ability to create a reliable, pictorial composition that architects, engineers, contractors and manufacturers can use to visualize the final prod uct in its completed state 19 when used at its full capaci ty . Generating a BIM model also gives the creator the opportunity to detect errors within the building systems, as well as coordination between trade responsibilities. Once a BIM model is complete with the approval of an architect and several engineers, i t can be used as the final template to prefabricate most elements of a future building by increasing component yield and quality, reduc ing the time of construction, decreasing waste and environmental impact on site, and creating a safer, controlled working environment for laborers 20 21 . Various stages of prefabrication can benefit from BIM application, as regardless of whether the 18 Eastman oductivity in the AEC Industries in the United States for On Site and Off Journal of Construction Engineering and Management , 134(7), 517 526. 19 Building Information Modeling (BIM) in Modul ar Proceedings, Construction Research Congress , ASCE, Banff, Alberta, Canada, 1136 1145. 20 Site Journal of Architectural Engineering , 18(2), 107 113. 21 Lu, 1136 1145
prefabricated elements are small preassembled components or entire module pods, the ultimate advantage that a model provides is a more efficient and cost effective way to eliminate time from the construction schedule 22 . With the use of this BIM technology that is continuously updated to include additional functions and provide new ways to be technically precise with data , m odular bu ilding has now become a viable option for high rise residential construction, with t he largest modularization challenge being the fabrication of mechanical, electrical and plumbing (MEP) systems 23 . Precise measurement and placement is required to be effecti ve in manufacturing operational modules, and producing a 3 D model for the purpose of MEP coordination seems to be an effective method to avoiding coordination issues when assembly of the module pods is required on site. Sustainable Applications and Waste Reduction It has become a driving force in the construction industry to use sustainable practices in design and construction when making considerations for a renovation or a new structure that is to change the landscape. When considering the finished desi gn and the construction methods to be used for a project, commercial buildings owned by corporations are being pushed by corporate social responsibility to strive for a greener structure 24 . With these sustainability requirements becoming more prevalent in b uilding, certifications such as Leadership in Energy and Environmental Design (LEED) 25 are commonly used to evaluate the performance abilities and sustainability and newly built or renovated structures based on certain green building criteria. As a means of constructing a multi story building that has the 22 Site Journal of Architectural Engineering , 18(2), 107 113. 23 Korman, T. and Lu, Improvements of Mechanical, Electrical, and Plumbing Systems for Modular Construction Using Building Proceedings, Architectural Engineering Conference , ASCE, Oakland, CA., 448 455. 24 Social Responsibility: An Innovation To A Strategic Business Success Babasaheb Gawde Institute of Management Studies , 1 5. 25 United States Green Building Council , U.S.G.B.C., (Mar. 1, 2016)
potential to create less waste, recycle what waste remains, produce less emissions and attain energy savings , reduce noise pollution, and improve safety on site, prefabrication has the ability to provide al l of these benefits 26 . When construction is done in the factory setting, material is used only when necessary and if there is any leftover, it can be readily recycled for another component or project 27 . Emissions are reduced since the amount of deliveries to and from the site are controlled by the amount of product that comes from the factory, and noise pollution is reduced because construction time is reduced when components come to the site preassembled. Safety is greatly increased in the factory setting, as laborers are working at a stationary site implementing predictable activities that do not give the opportunity for site intensive construction accidents 28 due to factory quality control standards. When prefabrication is increased to entire modules in mod ularization, these benefits provide even greater value to a project, with recorded waste reductions of 70% by efficient production practices, improvements in quality by reduced call backs, and less injuries on site by proven safer module construction sites 29 . Shipping and Delivery Scheduling Another facet of the prefabrication process that needs to be considered when deciding on a degree of prefabricated products in a project are shipping logistics and delivery schedules when transporting prefabricated item s from the factory to the site 30 . While cost and construction schedule time are greatly reduced in the prefabrication process in the factory, shipping the components is where accurate scheduling becomes essential for on time delivery to the site. When prefa bricated components 26 Lawson, R. M., Ogden, R. G., and Bergin, R. (2011). Rise Journal of Architectural Engineering , 18(2), 148 154. 27 Boy Site Journal of Architectural Engineering , 19(1), 51 57. 28 154 29 Site Construction o 51 57 30 Naqvi, D., Wey, E., Morgan, J., Miller, M., and Nguyen, T. Proceedings, Structures Congress , ASCE, Boston, MA. 1771 1781.
are being used, a lead time is given by the factory to the contractor and updates are given to have it delivered to the site at a time agreed upon by the factory and the contractor. In the case of modules being produced for a commercial modular building, an accurate schedule with the building times for each module, the amount of modules being produced per day, the amount of modules that can be shipped per day, and the amount of modules that can be installed per day all need to be conside red in the assembly schedule on site to precisely estimate the schedule for the erection process 31 . There are other considerations to be made directly related to the transportation of the prefabricated components or the modules, including but not limited to their physical size, weight, material composition, and center of gravity, as well as where the prefabrication factory is in relation to the site itself and the weather condit ions at the time of travel 32 . These factors can affect the method of how the compo nents or modules are shipped, whether it be by truck on the road or by barge on the water. These shipping methods can in turn be affected by how close in proximity the factory is to the building site, making it within the best interest of the parties invol ved to have the prefabricated materials as close to the site as possible to improve the schedule a nd cost implications. Location Considerations for Installed Prefabricated Units While the methods for constructing a multi story building with some level of prefabrication provides benefits that do outweigh techniques that involve only on site construction, in some cases geo graphica l location may affect whether or not using prefabricated systems are the best choice for a building , or whether more engineering needs to be factored into the design . Particularly with modularization, areas where seismic activity is more common gives reason to engineer the foundation, 31 Alvanchi, A., Azimi, R., Lee, S., AbouRi zk, S., and Zubick, Site Construction Planning Using Discrete Journal of Architectural Engineering , 18(2), 114 122. 32 Naqvi, D., Wey, E., Morgan, J., Miller, M., and Nguyen, T. Proceedings, Structures Congress , ASCE, Boston, MA. 1771 1781.
core and modules to withstand extreme earth disruption . Modules are typically constructed with stee l frames around a concrete core 33 , thus giving it a rigidity that cannot move as easily as other materials in the case of a great earth movement where the building must sway with the vibrations rather than fight them . In these areas, modules must be given a more malleable design regarding the structure so as to avoid this potentially fatal error, or else risk the building and its inhabitants. There are other ways to reinforce the modular building from a seismic event, but if ductility is not modified in the original design , 34 . Case Study Hilton Palacio del Rio Hotel in San Antonio, Texas d by the H. B. Zachry Company in 1968, just considerable amount of tourism, large companies, and important people to the area, and it was recognized that th attendance. The city council needed the fastest way to remedy the situation while still keeping to building and moral codes, and as chairman of the fair, H enry Bartell Zachry ( commonly known as H. B. Zachry) himself stepped up to the challenge 35 . The construction company ran a feasibility study and found that no traditional method of construction could have a hotel built in the nine months before the fair, so he suggested an inno vative construction method for its time. He proposed that his company could provide an entire 500 room hotel constructed of monolithic modular rooms that would be 33 Lawson, R. M., Ogden, R. G., and Bergin, R. (2011). Modular Construction in High Rise Journal of Architectural Engineering , 18(2), 148 154. 34 Naqvi, D., Wey, E., Sapaha, A., and Swamy, N. (2014). Proceedings, Structures Congress , ASCE, Boston, MA., 1752 1758. 35 21 Story Modular Hotel Raised The Roof for Texas Modular Building Institute , < h ttp://www.modular.org/htmlPage.aspx?HtmlPageId=40 0> (Feb. 18, 2016).
prefabri cated off site and assembled on the 54 foot by 350 foot site. Because of its proximit y to the piers had to be traditionally constructed first before the module placement process could begin. The first four floors of the building were also fashioned by usual on site construction methods to help provide a strong foundation. From there, slip form construction was used for the concrete and steel cores that house d elevator shafts and stairways at a height of 21 stories, and also serve d as t he central structures that connected the 16 stories made up of 496 modules to the core as a whole 36 . These modules were assembled i nto the multi story structure lifted by a crane, with modules staggered not only for a modern aesthetic appearance but also to add privacy to the balconies on each on the units. The final phase was topping off the building with conventional construction techniques by installing a metal roof deck that sealed the tops of the module units and built up the final floor that housed a b allroom and dining room areas. The modules were designed to be complete hotel rooms, and were put together by assembly line methods in a factory eight miles from the site. They were formed from light weight structural concrete and before being delivered t o the site, each module was fully outfitted with MEP connections ready for linking on site, finishes, and even furnishings. Finishes were of old Spanish design and there were five distinct styles assigned for each of the modules by Hilton standards. All fu rnishings, including lamps with bulbs, color televisions, and fully made beds, were bolted down in the rooms so as not to move during the lift and placement of the module. The units were 33 feet and 30 feet long, 13 feet wide, and 9 feet 6 inches high 37 . Ea ch module weighed up to 35 tons once complete, and the weight of all 16 hotel room floors needed to be supported by the strong foundation put into place at the outset of the 36 21 Story Modular Modular Building Institute , < h ttp://www.modular.org/htmlPage.aspx?HtmlPageId=40 0> (Feb. 18, 2016). 37 Modular Building Institute , 21 Story Modular Hotel
project. Once completed, each module was numbered with the hotel room number it wa s to receive in the hotel so as not to confuse those who were lifting and assembling the modules on site. These modules were manufactured and delivered in the order they were needed to the site, taking a total of 71 days to completely cast and furnish them all. The average placement of modules ended up at 17 modules per day once the operation became second nature to the crane operator and the assembly crew. The greatest number of modules placed in one day was 35 units, placing the equivalent of over one hot el floor at 31 modules. These room modules were finally placed and connected with onl y 100 days left until the HemisF air opening day on April 6, 1968 and H. B. Zachry Company scrambled to complete the top floor and all the finishes regarding the core shaft s that bond the modules to the building. The Hilton Palacio del Rio was completed on schedule before the rest of the structures for the construct a (most ly) prefabricated building by use of the modularization technique successfully. Summary and Conclusions The research and case study above demonstrate how prefabrication may affect the course of a project in any number of positive ways. Prefabrication in an off site setting provides a way for construction to be productive and efficient in a way that conventio nal, on site methods do not. Our society continues to develop more advanced technology that allows the opportunity for great adaptability for new building techniques through BIM. These developments are also pushing corporate social responsibility on corpor ations and other large conglomerates regarding sustainability and waste reduction techniques when building. These incentives to using prefabrication are paired with more beneficial products, including reduced project costs, abbreviated construction schedul es, safer working conditions, and less time crea ting disturbances on site among others. However, shipping and delivery logistics must be well thought out and predetermined before a project can begin, in addition to design
considerations regarding geographical location when choosing where prefabricated material can be erected or else risk imposing large cost implications to a project. B enefits of prefabricated construction were demonstrated in the case study of the Hilton Palacio del Rio hotel constructed in constructed in less than a year by correct usage of the modularization technique. As this building was constructed in the 1960s, the computer technology such as BIM was not yet inven ted, but painstaking time went into the design, engineering, construction, and planning of the modules individually and the hotel as a whole. Waste was reduced by work being completed by assembly line methods, and the site was only eight miles away from wh ere the modules were being constructed, allowing for ease of transport. Additionally, San Antonio, Texas was not knowledgably near any geographical fault lines that could allow for seismic activity, so additional design considerations and reinforcement did not need to be made for extreme earth movements. The Hilton Palacio del Rio was famously, and more importantly safely, constructed in a total of 202 working days, accomplishing what seemed like an impossibly fast schedule for constructing a 21 story build ing.
Bibliography Site Construction Planning Using Journal of Architectural Engineering , 18(2), 114 122. Azimi, R., Lee, S., and Abourizk, S. M. (2 Control: Case Study of Off Journal of Computing in Civil Engineering , 26(6), 681 690. Boyd, N., Khalfam, M., and Maqsood Journal of Architectural Engineering , 19(1), 51 57. Solutions for Design and Construction of a Su Proceedings, Structures Congress , ASCE, Chicago, IL., 953 964. Site and Off Journal of Constructio n Engineering and Management , 134(7), 517 526. Strategic Business Success Babasaheb Gawde Institute of Management Studies , 1 5. Proceedings, Architectural Engineering Conference , ASCE, Oakland, CA., 448 455. Lawso Rise Journal of Architectural Engineering , 18(2), 148 154. Based Analysis of Drivers and Constraints in the Use of Off Proceedings, International Conference on Construction and Real Estate Management, ASCE, Kunming, China, 26 36. eering Journal of Management in Engineering , 27(4), 229 235. Proceedings, Construction Research Congress , ASCE, Banff, Alberta, Canada, 1136 1145. Merriam Merriam Webster , Merriam Webster, (Feb. 19, 2016). Merriam Merriam Webster , Merriam Webster, (Feb. 19, 2016).
21 Story Modular Hotel Raised The Roof for Texas World Fair in Modular Building Institute , < h ttp://www.modular.org/htmlPage.aspx?HtmlPa geId=400> (Feb. 18, 2016). Proceedings, Structures Congress , ASCE, Boston, MA. 1771 1781. Naqvi, D., Wey, E., Sapaha, A., and Swamy Proceedings, Structures Congress , ASCE, Boston, MA., 1752 1758. Journal of Architectural Engineering , 18(2), 107 113. Portland C PCA , Portland Cement Association (PCA), < http://www.cement.org/cement concrete basics/products/precast concrete > (Feb. 13, 2016). Said, H., Ali, A., and Alshehri Proceedings, Construction Research Congress , ASCE, Atlanta, GA., 1977 1986. Proceeding s, Third National Congress on Civil Engineering History and Heritage , ASCE, Houston, TX., 440 460. Site Jou rnal of Architectural Engineering , 19(4), 279 287. United States Green Building Council , U.S.G.B.C., (Mar. 1, 2016) Yu, H., Al Hussein, M., Al Jibouri, S., and Telyas A. (2 Journal of Management in Engineering , 29(1), 103 111. Dependency Str Proceedings, International Conference on Computing in Civil and Building Engineering , ASCE, Orlando, FL., 1457 1464.