149 research outputs found
From Mass Prefab to Mass Customization. Modern Methods of Constructions from Experimentation to Manufacturing
No full textThis book provides an overview of the latest innovations in prefabrication. It analyzes how digital, material, and process innovations are transforming the mass prefabrication of homes, schools, and offices into mass customization. It provides an understanding of available manufacturing processes, including distributed ownership of manufacturing, platform approaches, and robotics. It discusses how the integration of cutting-edge advanced construction techniques, coupled with robotic manufacturing and assembly from the earliest stages of building system design, has the potential to unlock new formal and technical paradigms.
Investigating the impact of prefab in the context of climate emergency, the book analyzes the capacity and shortfall in delivering net zero emissions. It discusses the opportunities that Modern Methods of Construction provide to enable the transition towards circular constructions, from reuse to retrofitting. Including the users' experience, it demonstrates the importance of developing methodologies for capturing users' occupancy evaluation, as a means for understanding real performances, benchmarking indicators, and tuning systems to target the long-term well-being of the occupants.
Referring to a plethora of emblematic cases, this work demonstrates the importance of investing in research and development to optimize construction systems, reduce material use, facilitate lean construction, advance mechanical and environmental performances, and move toward circular systems to close the loop.
This book is aimed at practitioners, architects, technologists, researchers, and students in architectural engineering
Architectural Engineering: Engineering approaches for the Design for Manufacturing and Assembly for the Housing sector
No full textInvestigation of the effect of modular construction details on the lateral behaviour of cold-formed steel framed shear walls
No full textThis paper investigates the effect of modular construction details on laterally-loaded cold-formed steel (CFS) framed shear walls sheathed with wood-and cement-based panels by means of finite-element (FE) analyses. Shell FE-based models have been developed in ABAQUS with the aim of accurately capturing the behaviour, strength and stiffness as well as the corresponding failure modes of CFS framed shear walls subjected to monotonic lateral load (i.e., wind). User-defined element subroutines were adopted for precise modelling of sheathing-to-CFS screws shear behaviour. The proposed modelling protocol is validated using experimental test results, where an acceptable concordance (4% difference) has been achieved. Subsequently, the effect of modular construction details, which go beyond the scope of the current lateral design provisions (AISI S400), on the lateral behaviour of CFS framed shear walls is assessed. In particular, this paper investigates the impact of: (i) floor and ceiling ledger beams on the interior face of the shear wall, (ii) sheathing boards having different sizes from the overall shear wall and thus the presence of both vertical and horizontal seams, (iii) cement particle boards at the bottom stripe of the shear wall and (iv) different screw spacing in the top and bottom stripes from the middle part of the shear wall. The key parameters, which have most affected the lateral behaviour, were identified, and based on that, rules have been established for optimizing the screws pattern and sheathings layout efficacy in the above -described lateral load resisting system. The obtained results shed light on the capability of the developed modelling protocol to be used as a virtual test bench, particularly in offsite mass production and manufacture (DfMA), for the development of a new CFS framed wall system for lateral stability of lightweight modular houses
Life-cycle assessment of cold formed steel buildings: Main influential materials and parameters
No full textReducing the carbon footprint of the built environment is a duty to achieve the target of the 2030 Urban agenda. The built environment is, indeed, responsible for about 42% of of the EU total energy consumption and about 35% of the greenhouse gases emissions. One of challenges in reducing the impact of building on the environment is in quantifying them, with a good degree of accuracy. To this end, over the last decades, life cycle methodologies and met-rics have been developed for the assessment of green-house gases impacts of material, products, and components, that can be applied by academics and professionals. However, the quality of the assessment relies on the quality of data related to the amount of materials used for the stud-ied building or component, and the corresponding adopted embodied carbon coefficients. This paper aims to shed light on this two key aspects investigating the cradle – to – gate life cycle impacts of a cold formed steel building, for which high accuracy is provided in terms of amount of materials and for some of the embodied carbon coefficients. The results will provide a useful benchmark for the wider academic community in terms of environmental impacts of cold formed steel structures, which is still a under-investigated field, and shed lights on the uncertain-ties generated by the selection of embodied carbon coefficients
Can we reuse plasterboards?
No full textGypsum turns plaster when it is dehydrated, and it returns to gypsum when it is hydrated. Because of this, gypsum is 100 % recyclable in theory. However, in reality, only 4% (in mass) of the plasterboard is from recycled plasterboard. This is because of the substances, other than fresh gypsum from quarries, to make plasterboard, and the current demolition methods that cause material contamination. The current practice of manufacturing, construc-tion, and deconstruction of plasterboard necessitates significant resource extraction and carbon emissions, and the situation is unlikely to change in the foreseeable future. Reusing, instead of recycling, construction material is effective in reducing resource extraction and carbon emis-sions, however, it has not been investigated at all for plasterboard. Thus, this paper explores the potential and feasibility of reusing plasterboard used for exterior infill walls, which is made of plasterboards and an increasingly used façade construction method in the UK
Using bolted connections for the construction, de-construction and reuse of lightweight exterior infill walls: Experimental study
No full textBolted connections ofer advantages in terms of disassembly and reusability, potentially replacing conventional connections like screws, welds, or chemical bonds. This research investigates the behaviour of bolted connections between lightweight exterior infll walls and beams of primary structural members that are conventionally connected using screws. Although previous studies have investigated bolted connections in diferent structural members, understanding of the behaviours of these specific connections remains limited. The connections between infll walls and steel beams primarily experience shear loads under serviceability conditions. Therefore, an experimental study was conducted to gain insight into their shear behaviour. The obtained experimental results were analysed using existing predictive equations from design standards that
are used across European, North American and Oceanian countries, to identify the most suitable equations for designing such connections
Numerical investigation into the performance of cold-formed steel framed shear walls with openings under in-plane lateral loads
No full textRecently, there has been a resurgence in the adoption of lightweight cold-formed steel (CFS) profiles as structural elements in low- to mid-rise modular construction. Typically, openings for doors and windows are ever-present in the front and rear elevations where shear walls find their optimal position to ensure lateral stability in CFS modular structures. These architectural design features translate into reduced areas for lateral load resistance throughout the structure. This paper discusses the performance of CFS framed shear walls with openings under lateral loads through experimental tests and numerical simulations. Overall, three shear wall typologies were designed for force transfer around opening (FTAO) and tested under monotonic lateral loads (nine tests in total). An advanced finite element analysis (FEA) modelling protocol was elaborated to simulate the lateral behaviour of the tested walls as well as to interpret the physical tests. Evaluation of the numerical and experimental test results validated the FEA modelling protocol that demonstrated to be reliable in predicting the strength and stiffness as well as failure modes of CFS framed shear walls with openings subjected to lateral loads. The effects of sheathing-to-CFS screw spacing, the size and number of openings as well as the geometry of sheathing panels on the lateral behaviour of CFS framed shear walls were scrutinized. Subsequently, load-path mappings from the developed modelling protocol enabled the analysis of the flow of the in-plane lateral loads from the sheathing-to-CFS screw level into the wall system level where insight into a more efficient lateral design of CFS framed shear walls with openings have been highlighted. The obtained results shed light on the conservative nature of the AISI S400-15 design provisions for Type II shear walls and that of the perforated design methods available in the literature
Seismic analysis of sheathing-braced cold-formed steel structures
No full textThe seismic behavior of sheathed cold-formed steel (SCFS) structures is characterized by the lateral response of shear walls. Basically, if cold-formed steel (CFS) structures are designed according to the "sheathing-design" methodology, then the seismic behavior of shear walls is strongly influenced by the sheathing-to-frame connections response, characterized by a remarkable nonlinear response and a strong pinching of hysteresis loops. In this paper the results of an extensive parametric non linear dynamic analysis, carried out on one story buildings by means of incremental dynamic analysis (IDA), using an ad hoc model of the hysteresis response of SCFS shear walls, are presented. An extended number of wall configurations has been considered investigating several parameters such as sheathing panel typology, wall geometry, external screw spacing, seismic weight and soil type. Based on IDA results, three behavior factors have been defined, which take into account overstrength, ductility and both overstrength and ductility, respectively. Finally, a design nomograph for the seismic design of single-storey SCFS frame structures developed on the basis of non-linear dynamic analysis results is presented. This last aims to complete a proposal of a design methodology, already presented by the author in the last years
Future scenarios for housing (re)settlements in Ecuador
No full textPost-earthquake (re)settlements are too often the results of political decisions, driven by the urgency of housing survivors in emergency. There is very limited evidence of strategic decisions made for the long-term wellbeing of the displaced communities. This has certainly been the case, for the post-earthquake reconstructions developed in the aftermath of the 2016 Muisne earthquake in Ecuador. Previous research has indeed demonstrated, through qualitative empirical research, the failure of the developed resettlements from both a technical and a social perspective. This paper aims to re-think the way to conceive (re)settlements with the aim to co-produce with local experts and inhabitants possible future scenarios. A first pilot case, that adopts design solutions at the urban and housing unit level, which are strongly connected to the local geographic and cultural context, is discussed. This paper presents and discusses the design evolution of the proposed pilot case, posing the attention to the urban development and the housing design, articulated imagining the (re)settlement as a new neighbourhood of the city, with a combination of private and public spaces, that will grow and be fully integrated to the consolidated city as population grow
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