Search Results (18)

Beam-to-column connections govern both seismic performance and post-earthquake repairability of steel moment-resisting frames. Yet direct, apples-to-apples comparisons among welded, bolted, and repair-oriented replaceable-fuse moment connections are still scarce, which hinders rational selection for resilient construction. This study conducts a unified finite-element comparison of three representative joint archetypes—W-RBS, Bolted, and Prefab-web-fuse—under monotonic and cyclic loading. Consistent moment-rotation definitions are adopted, and normalized indices are introduced to compare hysteresis shape, degradation, and energy dissipation across joint concepts with different strength scales. Component-wise plastic dissipation is also extracted to quantify damage localization and assess main-frame protection and replaceability. Results reveal clear trade-offs: W-RBS provides the highest strength and dissipation but degrades most in stiffness; the bolted joint shows pinching due to interface compliance; and the web-fuse concept concentrates inelastic demand in a replaceable segment, supporting repairability-oriented design. The proposed framework offers mechanism-based guidance for selecting steel moment connections toward resilient and repairable frames. Full article

Facing a significant decrease in economic working processes, Off-Site Construction (OSC) methods have been frequently adopted in response to challenges such as declining productivity and labor shortages in the construction industry. Currently, in most OSC applications, the assembly phase is traditionally managed based on the personal experience and judgment of the site managers. This approach can lead to inaccuracies or omissions, particularly when dealing with a large amount of information on large, complex construction sites. Additionally, there are limitations in exploring more efficient and productive alternatives for rapidly adapting to changing on-site conditions. Given that the assembly phase significantly affects the OSC productivity, a systematic management approach is crucial for expanding OSC methods. Some initial studies used computer algorithms to determine the optimal assembly sequences. However, these studies often focused on geometrical characteristics, such as component weight or spatial occupancy, neglecting crucial factors in actual site planning, such as the work radius and component installation status. Moreover, these studies tended to prioritize the generation of initial assembly sequences rather than providing alternatives for adapting to evolving on-site conditions. In response to these limitations, this study presents a systematic framework utilizing a Building Information Modeling (BIM)–Genetic Algorithm (GA) approach to generate Precast Concrete (PC) component installation sequences. The developed system employs Genetic Algorithms to objectively explore diverse assembly plans, emphasizing the flexibility of accommodating evolving on-site conditions. Real on-site scenarios were simulated using this framework to explore multiple assembly plan alternatives and validate their applicability. Comprehensive interviews were conducted to validate the research and confirm the system’s potential contributions, especially at just-in-time-focused PC sites. Acknowledging a broader range of variables such as equipment and manpower, this study anticipates fostering more systematic on-site management within the context of a digitized construction environment. The proposed algorithm contributes to improving both productivity and sustainability of the construction industry by optimizing the management process of the off-site construction projects. Full article

Prefabricated building holds promise for quality, efficiency, and sustainability when compared to traditional techniques. However, realizing prefabricated building work hinges on strengthening supply chain resilience. This research assesses interdependent risks undermining prefab network continuity during disruption. Questionnaire data from industry experts informed a structural equation model quantifying pathways between component production, construction, information, and other uncertainties. Findings confirm that project delays can be traced to manufacturing and on-site risks, with information gaps broadly propagating impacts. Meanwhile, organizational risks have an insignificant influence, suggesting partnership networks readily reconfigure around operational contingencies. Robust information infrastructures and coordination, therefore, offer crucial leverage. Accordingly, a multidimensional resilience enhancement strategy is formulated, prioritizing supply chain transparency, digital integration, inventory buffering, contingencies planning, and transportation flexibility. Our mixed-methods approach advances the construction literature by demonstrating the applicability of structural equation modeling for diagnostic resilience analytics. Industry leaders also gain actionable, evidence-based guidance on strategic investments to stabilize project flows. This dual theoretical and practical contribution underscores the versatility of tailored statistical assessments in furthering construction innovation objectives within complex, uncertain environments. Full article

The future of panel housing estates is influenced by a number of factors. Although panel housing estates have seen their share of commentary and analysis from both supporters and de-tractors, there has been no comprehensive effort to explore the field of panel housing estates in terms of building thermal regeneration measures. This article focuses on the links between thermo-technical regeneration measures in panel housing estates, and the application of External Thermal Insulation Composite Systems (ETICS) and their impact on the urban environment of panel housing estates. The paper contains three main sections in which we (1) synthesize the literature, sources, building physics context, and assumptions for the occurrence of biodeterization in the facades of prefab residential housing located in housing estates; (2) compare the case studies and their results from the 2010–2021 field reconnaissance, in situ diagnostics, and laboratory analyses; and (3) identify/illustrate common features, the extent to which the quality of prefab residential housing located in housing estates with ETICS exterior surfaces is influenced by the environmental context, whereby we understand the whole process of the environmental assessment framework as an interrelated complexity of the interacting links between the environment, urban planning, architecture and construction sectors, supporting a holistic approach to the issue at hand. The results show that regeneration work, on the one hand, improves the urbanized environment and the energy potential of a housing estate; on the other hand, we encounter new manifestations of defects and disorders in the form of biodegradation of facades that we did not expect. Full article

This article provides a comprehensive understanding of small house practices, including the perspective of Finnish architectural experts, by conducting semi-structured in-depth interviews and proposing an individually designed house case study with a particular focus on cost and quality. Key findings based on main themes including the role and qualifications of the architect, architect’s involvement, architect’s fee, reasons to hire an architect, implementation, quality, and cost, highlighted that: (1) architect can assist small house projects in many ways, such as accurately identifying the client’s needs, choosing the most suitable layout, and applications for building permits; (2) allocating sufficient time for planning an average of six months is critical for the thoughts of both the architect and the client to mature in peace; (3) the share of architectural design in the total cost of the project is around 3–5%; (4) it is estimated that the total amount of small houses designed by an architect is between 10–20%; (5) an architect’s typical client is reported to be those who dream of a long-term home and are concerned with aesthetics as well as functional quality; (6) the client is always satisfied with the quality of the house designed by the architect; (7) while an individually designed home may seem more costly than a prefab home, an architect-designed home can be affordable as long as the budget is known from the start of the project. It is believed that this paper will encourage the participation of architects in small house projects that will be expanded and established in the Finnish residential construction industry. Full article

The construction industry has experienced phenomenal growth because of technological advancements in the past couple of decades. Prefabrication constitutes a sizeable share of this industry and is being adopted all over the world. The method of casting construction elements in a controlled environment and assembling them on-site has revolutionised the industry. Research on various aspects of the technology is ongoing around the world, and an impressive number of articles have been published. However, the prefab technology, materials used, and terminology have varied across locations, which may have hindered the method’s wider acceptability. By evaluating technical articles published between 1991 and 2022, this report analyses the present body of knowledge regarding prefab technology, its evolution, sustainability, and stakeholder views. This technology effectively contributes around 40% in time saving, 27% in cost reduction, 30% in reduced carbon emissions, and 84% in on-site wastage reduction. It also increases quality, gives a dependable alternative for meeting mass construction targets, is energy efficient, and provides environmentally conscious options. This paper contributes to the body of knowledge by providing a snapshot of the prefab industry spanning three decades, detailing a wide range of factors affecting the industry. Full article

Modern Methods of Construction with Offsite Manufacturing is an advancement from prefabricated technologies that existed for decades in the construction industry, and is a platform to integrate various disciplines into providing a more holistic solution. Due to the rapid speed of construction, reduced requirement of labour and minimised work on site, offsite manufacturing and prefabricated building systems are becoming more popular, and perhaps a necessity for the future of the global construction industry. The approach to the design and construction of prefab building systems demands a thorough understanding of their unique characteristics. Full article

Under the India “Housing for all” scheme, 20 million urban houses have to be constructed by 2022, which requires the rate of construction to be around 8000 houses/day. Previous results by the team show that present design methods for affordable buildings and structures in India need improvement. The challenges are the disposal of solid waste generated from agro-industrial activities and the energy peak demand in extremely hot and cold seasons. The development of bio-based urban infrastructure which can adapt to the climatic conditions has been proposed. Inclusion of sustainable materials such as agro-industrial by-products and insulation materials has resulted in effective environmental sustainability and climate change adaptability. Precast components are highlighted as a suitable solution for this purpose as well as to fulfil the need of mass housing. India has a lesser record in implementing this prefab technology when compared to a global view. For the first time, a novel and sustainable prefab housing solution is tested for scale-up using industrial waste of co-fired blended ash (CBA) and the results are presented here. A model house of real scale measuring 3 × 3 × 3 m³ was considered as a base case and is compared with 17 other combinations of model house with varying alignment of prefab panels. Comparison was made with commercially available fly ash brick and CBA brick with a conventional roof slab. A simulation study was conducted regarding cost and energy analysis for all the 18 cases. Various brick and panel compositions with CBA for housing were tried and the superior composition was selected. Similarly, 18 model houses of real scale were simulated, with different combinations of walls made of bricks or panels and different building orientations, to check the impact on energy peak cooling and cost. Results show that peak cooling load can be reduced by six times with bio-based prefab panels. Prefab construction can be considered for mass housing ranging above 100 housing units, each consisting of an area of 25 m². Full article

A balanced combination of heat flows creates suitable conditions for thermal comfort—a factor contributing to the quality of the internal environment of buildings. The presented analysis of selected thermal-technical parameters is up-to-date and suitable for verifying the parameters of building constructions. The research also applied a methodology for examining the acoustic parameters of structural parts of buildings in laboratory conditions. In this research, selected variant solutions of perimeter walls based on prefab cross laminated timber were investigated in terms of acoustic and thermal-technical properties. The variants structures were investigated in laboratory but also in model conditions. The results of the analyses show significant differences between the theoretical or declared parameters and the values measured in laboratory conditions. The deviations of experimental measurements from the calculated or declared parameters were not as significant for variant B as they were for variant A. These findings show that for these analyzed sandwich structures based on wood, it is not always possible to reliably declare calculated values of thermal-technical and acoustic parameters. It is necessary to thoroughly examine such design variants, which would contribute to the knowledge in this field of research of construction systems based on wood. Full article

In South Korea, radiant floor heating has been used from old housing to the recently constructed residential buildings, which is called “Ondol”. The Ondol system is generally a water-based system and it uses hot water as a heat medium provided by boilers fueled by natural gas. With great effort to reduce greenhouse gas emissions, electric Ondol panels have been increasingly applied to the recent residential buildings for floor heating. While the prefab electric Ondol panels were developed with the demand for dry construction method, the information about the prefab electric Ondol system is not sufficient. For the present study, the thermal performance of the prefab electric Ondol panels was investigated through field measurement. In addition, the heating energy and economic performance of the electric panel were compared with the conventional Ondol system. As a result, a significant surface temperature difference was observed. Moreover, the heating cost for the prefab electric Ondol system was more expensive than the conventional system, even though a heat loss was observed by the operation of the conventional system. Full article

This paper focuses on sustainable transportation of prefab products from factories to construction sites by ship. Since the transportation cost for all the prefab products of a construction site is mainly dependent on the number of cargo holds used on ships, a loading plan for prefab products that minimizes the number of holds required is highly desirable. This paper is therefore devoted to the development of an optimal loading plan that decides which prefab products are loaded into each cargo hold and how to pack these prefab products into the holds so that as few holds as possible are used. We formulate the problem as a large-scale integer optimization model whose objective function is to minimize the total number of cargo holds used and whose constraints represent the cargo hold capacity limits. We develop a heuristic to solve the problem and obtain a high-quality solution. We have tested the model and algorithm on a case study that includes 20 prefab products. We find that different cargo holds carry prefab products that have quite different densities. Moreover, the orientations of many prefab products are different from their default orientations. The results demonstrate the applicability of the proposed model and algorithm. Full article

Energy-efficient buildings, sustainable buildings, smart buildings, nearly zero-energy buildings, passive and active buildings are construction concepts widely recognised as setting the latest trends. The purpose of their design is to create an optimal thermal microclimate by means of heat flows that are either formed within it or enter into it. This research paper presents an analysis of the measurements of the density of heat flows, their spread in building constructions, all of which is examined in laboratory conditions and confronted with calculation models. The hypothesis of this research is to confirm or refute whether the computational models match the laboratory simulations in terms of thermal-technical parameters. The research uses a methodology designed for examining building constructions under virtually stable conditions. Two variants of external sandwich walls based on prefab cross laminated timber panels (variant A) and structural insulated panel (variant B) were proposed as the subject of the study. Both variants were subjected to research in laboratory conditions and computational simulations. For the sake of comparison, the calculation simulations that manufacturers of wood construction systems typically declare were also performed. The results of the analyses show significant differences between the theoretical or declared parameters and the values measured in laboratory conditions (7.5–32.6%). The deviations of the experimental measurements from the calculated or declared parameters were not as significant for variant A as they were for variant B. These findings show that for these analysed sandwich structures based on wood, it is not always possible to reliably declare calculated values of thermal-technical parameters. The publication is also a contribution to the current needs in the field of heating technology in terms of sustainability and the quality of internal environments. Full article

In this article, the issue of constructing slabs from unified small elements, which are connected together into a stable structure by topological interlocking, is considered. The state-of-the-art methods in this topic are presented, as well as the results of the author’s original research. The author has expanded the well-known concept of shaping square slabs from square prefabs by the aggregation of triangular and hexagonal slabs from prefabs in the shape of equilateral triangles, regular hexagons, and rhombuses. Each of the slabs can be modelled with upper and bottom surfaces, either both relief, both smooth, or one relief and the other smooth. The slabs can be modelled in different ways, and each one results in intriguing floor and ceiling patterns. All of the slabs can co-operate with grillages made of steel beams, which can be constructed before filling with the prefabricated slab, which is a novel idea. Reversing the assembly order, as compared to that used in the literature, is made possible thanks to division of these elements into parts, to form a keystone which is inserted into the slab as a final step. Full article

Prefabrication (PC) projects have many advantages, such as cost and energy savings and waste reduction. However, some problems still exist that hamper the development of prefabrication projects. To improve PC project performance and advance innovation in construction, this study introduces an innovative method that incorporates Radio Frequency Identification (RFID) and Long Range (LoRa) technologies, sensor networks, the BIM model and cloud computing to automatically collect, analyze and display real-time information about PC components. It can locate PC components on a construction site and monitor their structural performance during the installation process. RFID technology and strain sensors were used to collect the required data on a construction site. All the data was transmitted to a server using LoRa technology. Then, the cloud-based Building Information Modelling (BIM) model of the project was developed to store and vividly present project information and real-time onsite data. Moreover, the cloud-based BIM model enables project team members to access the project information from anywhere by using mobile devices. The proposed system was tested on a real PC project to validate its effectiveness. The results indicate that the sensor network can provide reliable data via LoRa technology, and a PC component can be accurately located on site. Also, the monitoring data of structural performance for the PC component during the installation process is acceptable. The proposed method using innovative technologies can improve PC project performance and help industry professionals by providing sufficient required information. Full article

Volumetric prefabricated building construction is growing in most developed countries; for example, in Sweden the market share of prefabricated building systems in the housing industry was more than 80%. However, in Australia only approximately 3–4% of new building constructions are prefabricated buildings in a year. A major hindrance to the growth of prefab construction in Australia is that systems are developed under commercial and confidential conditions. There are limited publicly-available research and case studies for certifiers, regulators, engineers and academia to provide independent information on the performance, advantages and disadvantages of prefabricated building systems. Independent designers and structural engineers are relying on the strength of the structural and non-structural element, as well as the connections of the prefabricated building systems. This strength is estimated from the “commercial-in-confidence” test of individual components by manufactures, and it might result in undesired outcomes in design. This paper provides an overview of available literature on structural performance, benefits, constraints and challenges of prefabricated building systems. This paper also highlights the research needed on the prefabricated building systems such as full-scale tests, numerical modelling, hybrid simulations, case studies and social and economic assessments. Being supported by sound academic research will increase the market demand for prefabricated building systems in Australia as well as in other countries. Full article