Prefabricated construction has been a common construction method for American construction for more than a century. The concept of build it fast in the most economical way has not changed since the beginning; however, the new technologies have been developed to suit the modern world prefabricated construction. The new technologies are not only help contractors and owners get their building faster and more economical but they also help reduce construction waste and produce high energy efficiency buildings which result in a long term benefit to projects. On the other hand, prefabrication for residential construction has been used in Thailand for only less than two decades. However, the prefabrication construction in Thailand has grown rapidly from the past five years. Recently, there are many new developers, and contractors who have switched from a traditional construction to prefabrication to keep up the rising in Thai residential market. Moreover, the new minimum wage policy from Thai government has hit Thai construction business very hard. The labor cost has raised more than 40% in some area (Thai Department of labor, 2013) since 2012. Thai developers see prefabrication as a future and ready to invest more in this type of construction. (Krunthep Thurakit, 2013) Currently, there are many construction products from the U.S. which have been using in Thai construction. Thai people are familiar with American product, therefore, U.S. prefabricated products and methods can easily make a quick transition to Thai prefabricated construction. The intention of this research is to find the prefabricated residential construction products or method from the U.S. that can be used for developing the new or similar products that compatible with Thai market. There are a lot of strong potential prefabricated construction products and method in the U.S. which can be very useful in Thailand. Those can be benefit to both American investors and Thai construction. The selected products or method will be review and investigate in the categories such as performance, compatibility, availability, price and ability to adapt to Thai market.

This paper describes a method for the design and fabrication of complex funicular structures from discrete precast concrete elements. It has a critical look over conventional casting methods and proposes a parametric casting mold to produce concrete blocks with custom shapes. The research proposes that through the integration of digital form-finding techniques, computational file-to-fabrication workflows, and innovative sustainable casting techniques, complex funicular structures can be constructed using prefabricated elements in a practical, affordable, and materially efficient manner. / text

No description available.

It is important for an architect to understand the limiting factors that will affect the design of a modular building. The implementation of modular construction as a means of improving production efficiency and worker safety in the construction industry raises into question the design quality of modular buildings, and whether or not the merits of the building process can also be captured from the perspective of the architect. For this reason, the constraints and barriers to design innovation in modular construction are recorded through the lens of an architect. This study uses interviews with modular manufacturers to extract information on the topic of innovation in the industry. Featuring a case study project as the platform for discussion, the opinions of experienced building professionals were sought to identify what is and what isn't possible. Among the primary constraints and barriers to innovation, including manufacturing costs, dimensional requirements based on transportation method, and the inflexibility of CAM software, the results of the study identified a need for architects to become better educated about modular construction in general. Therefore, the information presented is meant to be a teaching tool geared towards architects. / Master of Science

The American way of life is becoming increasingly transient in nature. But at the same time there is also the inherent need to have a sense of rootedness, the need for a place to call home, to belong. The current thesis is an architectural exploration of creating a dialogue between this duality. The approach is to explore a composite system, where modular prefabricated architecture is implemented in conjunction with traditional building practices. The idea is to address the transient nature and sense of belonging by combining the prefabricated modular approach with the site-built traditional approach. This study proposes that there are two types of spaces in a house that creates the overall spatial experience of a home. These can be termed as core functional spaces and more fluid or flexible spaces. Core functional spaces are bedroom, kitchen, bathroom, dining, formal living etc. Flexible spaces are more fluid in terms of function, for example – family living, lobby, lounge, connecting/common spaces etc. In the current thesis, core functional units are proposed to be developed as modular units. The reason is, because of their defined functionality they can be designed as basic modules. The modules would be prefabricated in a factory and transported to site. The modules themselves are composed of panelised systems. This allows for a flexibility in different permutation of layouts and enables adaptability of the house with changing family dynamics and other functional needs, thus addressing the transient nature of life. The fluid spaces are proposed to be built on site allowing greater flexibility in terms of dimensions, construction material and design. This type of space addresses the sense of permanence and rootedness as they are designed to be responsive to the site forces and define the unique characteristics of a home based on client’s unique requirements. Overall, the composite approach addresses transience and changing family demographics through the modular, prefabricated, core functional units. Prefabrication is adopted for saving time and expenses of construction. Assembly line techniques, grouping of similar tasks and use of skilled labour help in achieving that. The core functional spaces serve some basic purposes which is common for every house in general. So these spaces can be considered as repeating units and forms, and can be considered for prefabrication. For example, Kitchens, bathrooms or bedrooms can be treated as basic units and thus can be designed as prefab modules. Prefabricated, modular construction is rapidly gaining interest in the building construction industry. Implementation of modular construction improves the efficiency in production and safety in the working environment. This reduces the necessity to transport many skilled workers to the construction site. Prefabrication also helps avoid other adverse conditions like exposure to harsh weather or a hazardous environment, lack of water or power etc. On the other hand, the proposed composite approach addresses permanence through the site-built components. These components are responsive to different sites and different client needs. The fluid spaces are the spaces that do not serve any specific or basic purpose for the designed architectural piece to function as a home, but rather work as a space that binds all the core functions together. The fluid spaces ne the architectural experience of a house and how the core functions are coming together to form an architectural piece that one can call home. For example, common lobby spaces, informal living, corridors etc work as fluid spaces where all the functional spaces are connected. For different households, different family needs, the fluid space can receive the functional modules differently thereby defining the architectural space differently. This type of spaces can be designed using traditional on-site construction which provides the language of permanence and rootedness. Proposed modular units themselves follow a panelised construction, so it is easy to add or remove panels to support the different arrangements of modules around different types of site built elements. Thus the composite system supports the transience by providing adaptability and permanence by responding and being rooted to the site. The overall spatial experience created by the juxtaposition of these two systems and two types of textures is the focus of this thesis. / Master of Architecture / Modern life is increasingly becoming fast and mobile. The idea of building one permanent accommodation for life that does not adapt to changes in family dynamics is increasingly going away. On the contrary, there is an inherent need in human beings to feel rooted to the place they live in. The current thesis aims to address this duality from an architectural perspective. The thesis proposes an architectural system that combines age-old, traditional architectural style with novel construction concepts. In traditional systems, houses were built from scratch, on-site. Which made them rooted to the place and directly influenced by the site. But new, prefabrication concepts propose constructing parts of a house as modules off-site, in a factory, and transporting them to the site. This off-site, module-based process makes a house easily adaptable to changes with changing family dynamics. This thesis proposes that there are two types of spaces in a house that creates the overall spatial experience of a home. These can be termed as core-functional spaces and flexible spaces. Core functional spaces are bedroom, kitchen, bathroom, dining, formal living etc. Flexible spaces are more fluid in terms of functionality, for example – family living, lobby, lounge, connecting/common spaces etc. In the current thesis, core functional units are proposed to be developed as modular, factory-built units. The reason is, because of their distinct functionality, they can be designed as modules. The modules would be prefabricated in a factory and transported to site. This approach enables adaptability of the house with changing family dynamics, thus addressing the transient nature of life. The flexible spaces are proposed to be built on site. This type of space addresses the sense of permanence and rootedness as they are designed to be responsive to the site forces and define the unique characteristics of a home based on client’s unique requirements. The architectural implementation presented here celebrates the coming together of these two types of building processes. Overall, the composite approach addresses transience and changing family demographics through the modular, prefabricated, core functional units. On the other hand, the proposed composite approach addresses permanence through the site-built components. The composite system supports the transience by providing adaptability and permanence by responding and being rooted to the site. The overall spatial experience created by the juxtaposition of these two systems and two types of textures is the focus of this thesis.

The use of modular construction systems for residential purposes currently represents a very small proportion of all housing construction. The focus of these systems is on niche markets typified as cheap alternatives, homeowner involvement in construction or adaptations to construction constraints (build time availability, site access, etc.). Governments, regulatory bodies and industrial members are progressively moving towards increased environmentally sustainable practice. This progression is evidenced by the development of design and construction rating tools and the introduction of statutes and regulations governing construction and design. This work investigates the improvement of residential construction practice in terms of environmental sustainability outcomes through the use of modular housing systems. Two key aspects of environmental sustainability identified are embodied energy and material waste reduction. A modular system has been investigated because methods and procedures that directly relate to these two areas are well addressed by such systems. In order to validate the potential of modular systems in this environmental regard, three main areas have been addressed. The first is the ability for modular systems to generate the type of floor plans currently offered by Australian high-volume builders. Second, the environmental improvement potential offered by modular systems is addressed. Lastly are the issues of structural performance and the means of the tailoring of prefabricated modular systems to residential construction standards. Through the treatment of these three areas, potential benefits of modular systems are identified, with future work necessary to implement such benefits highlighted. The need for such improvements is noted, and a framework for evaluating future developments in this area of research is presented.

No description available.

Houses are unique personal spaces and individuals want flexibility and personalization in building their dream house. There is a current challenge in the prefabricated housing industry in Sweden where customers have increasing design demands and options that in essence, defeat the purpose of fixed design and prefabrication. This causes strain to both the customer and the company’s design process and sustainability efforts. The purpose of the study is to map the customer demands in customization of prefabricated houses through the innovation process of ideation, realization, and implementation. The overarching strain in customization is due to (1) the complexity of choice in designing a house, and (2) the mismatch between customer demand and manufacturing capability. A design criteria with BIM was brought forward to aid in the customization process in being more objective for decision-making. Through a case project and a design criteria, a prefabricated house model was redesigned with maximized flexibility. The findings in this study is a contribution to the house manufacturers in Sweden as an aid in architectural design and client communication strategies.

This thesis deals with prefabricated composite bridges in general, and prefabricated concrete deck elements with dry joints in particular.As outlined in Paper I and Chapter 2 prefabrication has several advantages over in situ construction, and has hence been discussed for decades in the construction business. Further, the house building sector has taken large steps towards a more industrialized approach, in which prefabrication, lean thinking and Building Information Modelling (BIM) are all important components. Numerous studies have also examined the applicability of such an approach in the bridge sector, and several types of prefabrication techniques have been tested. Nevertheless, in many countries the bridge sector seems to lag far behind in the general shift towards more industrialized construction processes. One of the reasons for the relatively slow progress may be the fact that bridges are often unique objects with unique specifications and constraints. This hinders the standardisation that is often regarded as a key to industrialised construction.Chapter 2-3 and Paper I, presents evidence from a literature review together with information gathered from a Workshop, attended by bridge designers and researcher in Europe and the US, that prefabricated deck elements are still quite rarely used in bridge construction. Deck elements with dry transverse joints are even rarer. Few examples have been reported. In addition, the degree of prefabrication and the rate of progress towards more industrialised construction processes seem to vary substantially from one country to another.However, as described in Chapter 3 and Paper II, a prefabricated concrete deck element system with dry joints has been developed in Sweden for constructing composite bridges. The transverse joints are completely dry, and all forces are transferred by contact pressure between concrete surfaces. This implies that no tensional forces can be transferred over the transverse joints. Shear forces are transferred by overlapping concrete shear keys, designed as a series of male-female connections. The research presented in this thesis is focused on the structural behaviour of this deck element system. In order to investigate this, laboratory tests have been performed as well as field monitoring.Results of large-scale laboratory tests, presented in Chapter 4 and Paper V, show that a bridge of this type is less stiff than a similar bridge with an insitu cast deck slab. The concrete elements’ contributions to stiffness are negligible in sections with hogging moments, but make some contribution to global stiffness in sections with sagging moments. At moderate load levels, the interacting concrete area is much smaller than in a similar in-situ cast section. This is believed to be due to the combined effects of small gaps in the joints and continuous in-situ cast concrete in the injection channels.After the channels have been injected, existing gaps will be more or less permanent, since the in-situ cast concrete must be compressed up to a certain limit before the rest of the joint will be closed. Destructive testing showed that the differences in stiffness and stresses between a deck of this type and an in-situ cast bridge deck are much smaller in the ultimate limit state. In this case it could even be reasonable to design a cross-section according to Eurocodes, neglecting effects of the joints.As shown in Chapter 5 and Paper III, the overlapping shear keys are a critical detailing in this deck system. Therefore, they were tested in the laboratory to determine how they fail and evaluate their load capacity. The tests revealed two failure modes. The first is a rather ductile failure, activating the shear reinforcement. This was the expected failure mode for shear keys of this design. The second failure mode observed was a quite brittle failure in the concrete covering layer. It has only been observed in small-scale tests, and might be related to the test set-up. Nevertheless, overlapping of the rebars in the male-female shear key connection is strongly recommended to assure the robustness of shear transfer if failure occurs in the concrete covering layer.To complement the laboratory tests, a single span bridge was monitored in the field (Chapter 6 and Paper IV). The bridge was built in 2000, using the prefabricated deck system that this thesis is focusing on, and was tested in both 2001 and 2011. The tests, and subsequent Finite Element analyses, showed that under moderate loading the interacting concrete area is smaller than for a similar in-situ cast bridge. No significant long-term effects were observed, except that under eccentric loading the distribution of the deflection between the girders decreased slightly during the 10 years between tests. This indicates that the joint gaps may have narrowed and at least partly closed during this time.Chapter 7 summarises the research and presents recommendations for dealing with general issues related to the design and construction of a bridge of this type. The design methods are generally the same as for a conventional composite bridge with an in-situ cast deck slab. However, the Eurocodes require some modification for the design of prefabricated deck elements with dry joints, particularly regarding global analysis and the resistance of cross-sections. Finally, conclusions, a general discussion and suggestions for further research are presented in Chapter 8. / Denna avhandling behandlar ämnet prefabricerade samverkansbroar i allmänhet och prefabricerade betongelementfarbanor med torra fogar i synnerhetPrefabricering är ett ämne som har diskuterats i byggbranschen under de senaste decennierna. Husbyggnadsindustrin har gjort stora framsteg i riktning mot ett mer industriellt tänkande, i vilket prefabricering, Lean och BIM är viktiga pusselbitar. Även i brobranschen har mängder med forskningsprojekt utförts runt om i världen och flertalet olika prefabricering lösningar har testats genom åren. Trots detta så förefaller det så att brobranschen ligger lång efter i utvecklingen mot en mer industrialiserad byggprocess. Den långsamma utvecklingen kan till viss del förklaras av att varje bro ofta är ett unikt objekt med unika förutsättningar. Detta utgör ett hinder mot standardisering vilket ofta är beskrivet som nyckeln till industrialiserat byggande.En litteratur studie kompletterad med en Workshop, för insamling av information och erfarenheter från brokonstruktörer och forskare i Europa och USA, visar att prefabricerade farbaneelement fortfarande är ganska ovanliga på den globala byggmarknaden. Farbaneelement med torra fogar förefaller vara extremt ovanliga, enbart ett fåtal exempel har påträffats i litteraturstudien. Prefabriceringsnivån och utvecklingstakten mot ett mer industriellt byggande varierar mycket från ett land till ett annat. (Paper I och Kapitel 2-3)För samverkansbroar har ett prefabricerat farbanesystem med torra fogar mellan betongelementen utvecklats i Sverige. De tvärgående fogarna är helt torra och all kraft överförs genom kontakttryck mellan olika betongytor. Detta medför att inga dragkrafter alls kan överföras genom fogen. Tvärkrafterna överförs genom överlappande betongklackar som är utformade som en serie av hane-hona kopplingar. Forskningen som presenteras i denna avhandling är fokuserad på konstruktionens strukturella beteende. Detta beteende har undersökts via labbtester såväl som genom fältförsök. (Paper II och Kapitel 3)Storskaliga labbtester visar att en bro av denna typ är mindre styv än en liknande bro med en plastgjuten farbaneplatta. I områden med negativt böjmoment är betongelementens bidrag till styvheten försumbart. I områden med positivt böjmoment bidrar betongelementen till den globala styvheten. Vid måttlig belastning är dock den medverkande betongarean avsevärt mindre än i en motsvarande platsgjuten konstruktion. Detta orsakas förmodligen av de små glipor som finns i fogarna, i kombination med det faktum att de injekterade kanalerna är kontinuerliga över elementskarvarna. Detta medför att de initiala fogöppningarna mer eller mindre blir permanenta då kanalen injekteras, eftersom den injekterade betongen i kanalen måste tryckas samman till en viss gräns innan den resterande delen av fogen stängs. Förstörande provning visar dock att skillnaderna i spänningar och styvhet är avsevärt mindre i brottgränstillståndet. Det är därför rentav rimligt att utföra tvärsnittskontroller, i brottgränstillstånd, i enlighet med de regler som anges i Eurokoderna och därmed försumma de effekter som fogarna ger upphov till. (Paper V och Kapitel 4)De överlappande betongklackarna är en väsentlig detalj i det aktuella prefabriceringssystemet. Dessa klackar har därför testats i ett laboratorium för att för utreda hur de går i brott samt vilken last kapacitet som de har. Testerna resulterade i två olika typer av brott. Den första typen av brott aktiverade skjuvarmeringen, vilket resulterade i ett tämligen duktilt brott. Denna var även det förväntande brottscenariot och tämligen i linje med de dimensionerings metoder som föreslås för denna typ av betongklackar. Den andra typen av brott som observerades var ett tämligen sprött brott i betongens täckskikt. Denna typ av brott har enbart observerats i dessa labbtester och är möjligen relaterad till utformningen av testriggen. Det rekommenderas dock starkt att utforma armeringen i klackarna så att armeringsjärnen i hona-hane överföringen överlappar varandra. Detta för att säkerhetsställa en residualhållfasthet för skjuvöverföringen även efter ett eventuellt brott i betongens täckskikt i klackarna. (Paper III och Kapitel 5)Som ett komplement till labbtesterna har fältförsök utförs på en enspannsbro. Den aktuella bron byggdes år 2000 med den prefabriceringsteknik som denna avhandling behandlar och har instrumenterats såväl år 2001 som 2011. Även dessa tester och de efterföljande FE-analyserna visar att den medverkande betongarean, under måttlig belastning, är klart mindre än den medverkande arean för en platsgjuten betongfarbana. Inga väsentliga långtidseffekter har kunnat observeras. Enbart nedböjningsfördelningen mellan balkarna, vid excentrisk last, har minskat en del efter 10 år. Denna skillnad kan indikera att fog öppningarna var större år 2011, dessa kan åtminstone delvis ha stängts under den tid som förlöpt mellan testen. (Paper IV och Kapitel 6)Huvuddelen av denna avhandling avslutas med ett kapitel som summerar den utförda forskningen genom att presentera råd och förslag på hur det går att hantera generella konstruktions- och produktions-frågor för en bro av denna typ. Dimensioneringsmetoderna är i regel de samma som för en konventionell samverkansbro med platsgjuten farbana. För denna typ av prefabricerade farbaneelement finns det dock vissa områden där dimensioneringsreglerna i Eurokoderna bör modifieras eller rentav ändras. Systemanalys och tvärsnittskontroll är två av de dimensioneringssteg där reglerna i Eurokoderna bör modifieras en del. (Kapitel 7)

No description available.