Search Results (619)

The British colonial contact with Nigeria was dotted with diverse paradoxes. In the realm of architecture, it was a period punctuated with the importation of prefabricated buildings into many slave and palm oil trading towns, such as Old Calabar in southern Nigeria. Unfortunately, today, many of these prefabricated colonial architectural heritages have gone into extinction, except for a few which are also on the verge of collapse. One of the remaining few on the verge of collapse is the Egbo Egbo Bassey House built between 1883 and 1886 and declared a National Monument of Nigeria in 1959. Currently, there is no literature on the historical and architectural data of this building, besides those scattered over several files in archival records. Therefore, this paper aims at the holistic documentation of the National Monument. Two categories of data were considered in the documentation processes—namely the building historical data and geometrical data. Historical data were collected through archival research and interviews, while the geometrical data were collected through close-range photogrammetry and manual measurements. The result of this paper contributes to the current geographical dearth of literature on British prefabricated architectural heritage, which punctuated a very important period in the architectural history of the world. Full article

In the newly developed hybrid prefabricated RC-steel structure (SS) foundation pit bracing system, the main braces are the main load-carrying components, which are assembled from standardized prefabricated reinforced concrete beam segments (referred to as beam segments). To facilitate assembly, beam segments are equipped with beam sleeves and beam-end connection holes. The holes at the end of the beam can cause stress concentration problems, while the beam sleeve has a reinforcing effect on the end of the beam segment. To investigate the influence of beam-end holes and beam sleeves on the compressive mechanical properties of beam segments, a numerical simulation study was conducted. Taking the beam segment (specification: 4500 mm × 700 mm × 800 mm) used in a certain foundation pit support project as the research object (i.e., specimen), Abacus software was first used to build parameterized models of beam segments with holes and beam sleeves using the concrete damaged plasticity model (CDP) and the steel double-line strengthening model. Then the influence of three factors, namely end face friction coefficient, beam-end holes diameter, and beam sleeve thickness, on the axial compression performance of the beam segment specimens was studied. The results indicated that the axial compressive capacity of specimens without a beam sleeve decreased with increasing hole diameter; the axial compressive bearing capacities of specimens with hole diameters of 35 mm, 40 mm, and 45 mm were 13,300 kN, 12,500 kN, and 12,300 kN, respectively, which are 11.3%, 16.7%, and 18% lower than the compressive bearing capacity of specimens without holes (15,000 kN). When both a beam sleeve and holes were present, the holes had a negligible influence on the compressive capacity, while the beam sleeve played a decisive role. The compressive bearing capacity increased with greater beam sleeve thickness; the peak bearing capacities of the specimens with beam sleeves 5 mm, 10 mm, and 15 mm thick were 16,200 kN, 16,500 kN, and 17,600 kN, respectively. As the end face friction coefficient decreased from 0.6 to 0.1, the location of maximum compressive damage shifted toward the end face of the beam segment, and the area of maximum concrete damage gradually migrated toward the hole locations. The study demonstrates that the confinement effect of the beam sleeve can compensate for the weakening effect caused by the holes and confirms that the designs of holes in beam segment ends and in the beam sleeve can meet safety requirements. Full article

In order to surmount the characteristics of high steel consumption and cost in prefabricated buildings, as a novel structural component, reinforced concrete vierendeel sandwich plates (RC-VSP) could be effectively employed. However, RC-VSP is restricted by complex construction procedures and rigorous quality control demands. Reliable reinforcement connections are the keys to their prefabrication. This study employed the methods of 1:1 full-scale comparative tests and numerical analysis through finite- element modeling. It compared the mechanical behaviors of the continuous reinforcement control group and the upset sleeve assembly group under four-point cyclic bending conditions. It analyzed how sleeves’ distribution influences structural stress states and crack propagation processes. The results show a superior ductility and damage resistance, on the basis of the components’ attenuation amplitude of the secant stiffness remains around 50% after the loading test with a deflection of 1/100, and the equivalent damping ratio is greater than 13%. Furthermore, the high similarity of the strain responses demonstrated the connection achieves prefabricated structures’ “equivalent performance to cast-in-place ones”. Additionally, the sleeve joints have slightly better stiffness, minor stress concentration at sleeve ends. This study offers robust experimental and theoretical support for the integrated prefabricated application of RC-VSP and further facilitates the development of building structures toward higher efficiency and lower carbon emissions. Full article

The incorporation of agricultural waste into construction materials represents a promising pathway toward achieving carbon neutrality in the building sector. This study investigates the flexural performance of a novel prefabricated external wall panel composed of corn straw concrete (CSC), an eco-friendly composite material that utilizes waste corn straws. While prior studies have explored rice straw and hemp fiber concrete, they primarily focused on the mechanical properties of these materials rather than the design of prefabricated panels. This study fills the gap by optimizing reinforcement ratio and window opening layout for CSC panels, and validating their structural viability for prefabricated enclosures. An optimal mix proportion was identified, which meets the mechanical requirements for non-load-bearing applications. Four prototype panel specimens were subjected to out-of-plane monotonic loading, considering variables including reinforcement ratio (0.18% vs. 0.24%) and the presence of a window opening (25% area ratio). Results indicated that increasing the reinforcement ratio significantly enhanced the ultimate load capacity by up to 33.3% (from 45 kN to 60 kN)—an enhancement effect that was 12–15% higher than that of reported rice straw concrete. In contrast, the introduction of an opening reduced the ultimate load capacity by 11.1–16.7%. A detailed nonlinear finite element model (FEM) was developed and validated against experimental results. The validation results indicated deflection error of 7.7–12.8% (mean: 9.33%; SD: 2.05), ultimate load error of 7.7–11.1% (mean: 9.48%; SD: 1.32), and a correlation coefficient (R²) of 0.96 between simulated and experimental values. Furthermore, analytical methods for predicting the cracking moment (with an average error of 5.97%) and ultimate flexural capacity, based on yield line theory (with an average error of 8.43%), were proposed and verified. This study demonstrates the structural viability of CSC panels and provides a sustainable solution for waste reduction in prefabricated building enclosures, contributing to greener construction practices. Full article

Precast concrete sandwich panels (PCSPs) have been widely adopted for constructing exterior walls in prefabricated residential buildings, but they face threats from impact loads such as natural disasters, terrorist attacks, and runaway vehicles. Their impact performance directly affects the overall safety and durability of the structure. However, research on the impact performance of such exterior walls remains limited. In this study, LS-DYNA R11 software is employed to establish a numerical model of PCSPs. The proposed numerical simulation method is validated by comparing the results with existing experimental data. On the basis of this numerical method and adopting an actual prefabricated residential building project as the background, the damage behavior of three distinct types of PCSPs in a bedroom is numerically investigated under varying impact location and energy conditions. The results demonstrate that the interior wythe of the PCSPs studied in this work exhibit excellent stability under external impact loading, with the most of damage absorbed by the exterior wythe, which provides effective protection to the interior wythe. Compared with windowed PCSPs subjected to impact, loads at the same energy level exhibit concrete spalling and a more pronounced dynamic response. Additionally, the windowed surface of L-shaped PCSPs is more susceptible to generating significant dynamic responses, with the non-windowed side exhibiting at least 13.2% lower maximum displacement under impact compared to the windowed side. Full article

Achieving a decarbonized built environment in Canada requires proven, resilient, and scalable building envelope assemblies. In 2022, building operations accounted for 18% of Canada’s greenhouse gas (GHG) emissions, with space heating responsible for nearly two-thirds of this total. Alongside operational carbon reductions, embodied carbon emissions—stemming from the production and transport of building materials—must be prioritized during the design phase. Without intervention, construction materials could consume up to half of the remaining global 1.5 °C carbon budget by 2050. This paper highlights NRCan’s prototype, low-carbon, prefabricated panels filled with chopped straw and cellulose insulation under the Prefabricated Exterior Energy Retrofit (PEER) research project. The research advances confidence in performance and durability of biogenic materials by conducting controlled experiments, guarded hot box testing, and hygrothermal modelling. These panels present a promising pathway to drastically lower embodied carbon in the built environment. The validated hygrothermal model, accurate to between 3% and 7, enables assessment of hygrothermal performance across Canadian climates, retrofit scenarios and future climate conditions. This work supports the evidence for low-carbon or bio-based materials as a solution for Canada’s built environment. Full article

The construction of prefabricated timber buildings is a topic of growing interest, although research has primarily focused on technological aspects, while the users’ perspective remains underexplored. Accordingly, this paper aims to map the existing literature on prefabricated wooden buildings from a user-centered perspective, considering the whole-building scale. A systematic literature search of publications between 2010 and 2025 was conducted following PRISMA guidelines, identifying relevant studies. A bibliometric analysis was then performed to map key research themes, which were further examined through a scoping review. Four main themes emerged, i.e., indoor comfort, indoor air quality, sustainability and energy efficiency, and building architectural design. The findings highlight numerous aspects that should be considered in prefabricated timber buildings design, including thermal, vibrational and acoustic comfort, air pollutant and ventilation control, user behavior in relation to energy use, and spatial design based on users’ needs. However, the limited number of existing studies makes comprehensive evaluation difficult. Furthermore, the results emphasize the need for multidisciplinary approaches to adequately integrate user experience into the design of these buildings. Full article

Europe, including Poland, is undergoing an energy transition. The use of renewable energy sources (RES) in the national energy sector is increasing significantly, and previously unused areas are increasingly developed for photovoltaic power plants. A specific type of housing common in Eastern European countries opens an additional opportunity for photovoltaic installations without occupying usable ground area. This article aims to analyze the potential for utilizing balconies and loggias in large-panel buildings, which are characteristic of major cities in Poland. Approximately 30% of the population resides in such housing. This presents significant potential for direct use of renewable energy by apartment residents. The article also explores the legal framework for such installations, both as individual investments by apartment owners and as collective initiatives managed by building administrators. The authors analyzed the potential performance of photovoltaic installations under varying azimuths and tilt angles, considering solar irradiation potential. The analyses also encompassed different photovoltaic module technologies, covering a spectrum of photovoltaic technologies, from commonly used monocrystalline panels to advanced transparent BIPV (Building-Integrated Photovoltaics) solutions. Furthermore, the study quantified the energy potential of such installations and compared the results with existing photovoltaic capacities and electricity demand in Poland. Full article

Against the backdrop of policy-driven transformation in construction industrialization, the EPC general contracting model has emerged as a core pathway for the large-scale development of prefabricated buildings. However, the EPC mode integrates the links of design, procurement, production, and transportation, construction, resulting in a complex coupling correlation among the risk factors of prefabricated construction schedule, which is easy to induce the risk contagion effect and increase the difficulty of risk control of project schedule delay. To address this, this study constructs a hybrid model integrating the “Fuzzy Interpretive Structural Model (FISM)-Coupling Degree Model-Bayesian Network (BN)” to systematically analyze risk contagion mechanisms. Taking an EPC prefabricated building project as an example, FISM is used to reveal the hierarchical structure of risk factors, while the coupling degree model quantifies interaction strengths and maps them into the BN to optimize conditional probability parameters. Through comprehensive hazard analysis, seven key causal risk factors and two critical risk propagation paths are identified. Targeted control measures are designed for the key risk factors, and BN-based simulation is applied to locate critical risk nodes and implement break-chain interventions for the risk paths, resulting in a 23% reduction in the probability of schedule delay. Engineering applications demonstrate that this model can effectively achieve the dynamic identification and blocking of risk paths, providing valuable reference for similar projects and offering informed support for managers in formulating scientific response strategies. Full article

With the development of prefabricated buildings, the challenge of integrating fireproofing and anti-corrosion in steel structures has become increasingly prominent. Based on epoxy resin, we developed a multifunctional coating with high-flame retardant efficiency and corrosion resistance, which can be employed in the key parts of modular integrated construction (MiC), thereby enhancing the safety of the prefabricated buildings. Experimental data showed that the fire resistance limitation reached 124 min, the salt spray resistance 2540 h, and the adhesion grade 1. The limiting oxygen index (LOI) of the cured coating was 45%, corresponding to the V-0 classification in the vertical burning test from Underwriters Laboratories Inc. (Northbrook, IL, USA) (UL 94). Compared with the latest studies, the integrated formulation exhibits simultaneous gains in fire and corrosion protection, offering a promising single-layer solution for MiC. Full article

Prefabricated building projects represent industrialized and intelligent construction through factory production, standardized design, and mechanized assembly. This study presents a multi-agent simulation approach to model the prefabricated construction process, allowing for the concurrent optimization of the prefabricated component (PC) splitting design and the construction organization plan through iterative simulation. (1) Employing a questionnaire survey, it identifies critical factors affecting schedule and cost from a design–construction coordination perspective. (2) Based on these findings, an agent-based model was developed incorporating PC installation, crane operations, and storage yard spatial constraints, along with interaction rules governing these agents. (3) Data interoperability was achieved among Revit, NetLogo3D and Navisworks. This integrated environment offers project managers digital management of design and construction plans, simulation support, and visualization tools. Simulation results confirm that a hybrid resource allocation strategy utilizing both tower cranes and mobile cranes enhances resource leveling, accelerates schedule performance, and improves cost efficiency. Full article

The demand for energy-efficient construction in agriculture calls for a reassessment of materials used in livestock buildings. This study evaluated the use of timber as an alternative to traditional materials, with a focus on embodied energy (EE) and carbon footprint (CFP) Eight EU countries (Germany, Poland, Spain, Italy, Denmark, France, Sweden, and Finland), were analyzed considering both forest resources and livestock populations. The forest area varied from more than 310,000 km² in Sweden to just 6464 km² in Denmark. Meanwhile, livestock populations varied significantly, with Germany reporting over 8.2 million LSU (livestock unit, 500 kg) in cattle alone. The number of livestock buildings was estimated assuming 100 LSU per building, allowing for a comparison between timber and conventional designs. Timber-based cowsheds were found to lower embodied carbon by up to 10,433 kg CO₂e per barn compared with 17,450 kg CO₂e for conventional structures. Embodied energy for a single wooden cowshed was around 151 GJ versus more than 246 GJ for a traditional counterpart. Scaled up to the national level, this represents a 35–40% reduction in total embodied energy. In addition to environmental outcomes, the analysis considered economic, technical, and regulatory aspects influencing adoption. The results suggest that substituting conventional materials with timber can contribute to emission reductions in agricultural construction, while further research is needed on fire safety, prefabrication, and policy harmonizations. Full article

Deep retrofits are one of the few pathways to decarbonize the existing building stock while simultaneously improving climate resilience. These retrofits improve insulation, airtightness, and mechanical equipment efficiency. NRCan’s Prefabricated Exterior Energy Retrofit (PEER) project developed prefabricated building envelope retrofit solutions to enable net-zero performance. The PEER process was demonstrated on two different pilot projects completed between 2017 and 2023. In 2024, in partnership with industry partners, NRCan developed new low-carbon retrofit panel designs and completed a pilot project to evaluate their performance and better understand resiliency and occupant comfort post-retrofit. The Low-Carbon Climate-Resilient (LCCR) Living Lab pilot retrofit was completed in 2024 in Ottawa, Canada, using low-carbon PEER panels. This paper outlines the design and construction for the pilot, including panel designs, the retrofitting process, and post-retrofit building and envelope commissioning. The retrofitting process included the design and installation of new prefabricated exterior retrofitted panels for the walls and the roof. These panels were insulated with cellulose, wood fibre, hemp, and chopped straw. During construction, blower door testing and infrared imaging were conducted to identify air leakage paths and thermal bridges in the enclosure. The retrofit envelope thermal resistance is RSI 7.0 walls, RSI 10.5 roof, and an RSI 3.5 floor with 0.80 W/m²·K U-factor high-gain windows. The measured normalized leakage area @10Pa was 0.074 cm²/m². The net carbon stored during retrofitting was over 1480 kg CO₂. Monitoring equipment was placed within the LCCR to enable the validation of hygrothermal models for heat, air, and moisture transport, and energy, comfort, and climate resilience models. Full article

As a common engineering building material, concrete material is widely used in buildings, bridges, and protective structures. Concrete load-bearing columns are one of the main load-bearing components in buildings. In order to analyze the change rule of strength of plain concrete column under small size impact damage, the impact concrete test of 11 mm prefabricated tungsten alloy spherical fragment at different speeds was carried out, and the damage parameters of concrete were obtained. The numerical simulation was carried out with the concrete material model under the experimental strength. Based on the obtained material parameters, five initial variables of load (10–30 MPa), column side length (0.1–0.3 m), fragment velocity (500–1500 m/s), impact angle (0–45°), and position height (200–400 mm) were numerically simulated. Based on the action law of each variable on the concrete column, a comprehensive numerical calculation of orthogonal optimization with five variables and five levels was carried out. The calculation results show that the structural strength of concrete is mainly affected by the side length of the column, and the initial velocity of the fragment determines the size of the loss mass. The greater the load on the concrete column, the greater the height of the position, and the more easily the column collapses; when the side length of the concrete column reaches more than 250 mm, the fragment has little effect on the overall strength of the concrete column. Through the results obtained in this paper, it can be further extended to the evaluation of damage of building components under different loads, so as to obtain whether the bearing level of damaged concrete components can meet the requirements. Full article

EPS module buildings are prefabricated, low-rise systems with high thermal insulation that are widely used in rural self-built houses in northern China, yet their indoor thermal environments often suffer from instability. This study experimentally verified the effectiveness of microcapsule phase change mortar (PCM plaster) in improving winter indoor temperatures of EPS module houses. In addition, based on simulation data from 350 design combinations across five representative cold-climate cities and four envelope design variables, the study provides quantitative design guidance for EPS module walls and PCM plaster in rural houses, offering a practical approach to improve indoor thermal stability that has not been previously reported. The main findings are as follows: (1) The thermal transmittance of EPS module walls is the dominant factor influencing indoor thermal performance. For climate adaptability, Type II walls are recommended for severely cold regions, while Type I walls are suitable for cold regions. The application of PCM plaster is not recommended in solar-rich cold regions such as Lhasa due to limited effectiveness. (2) Optimal PCM plaster parameters exist, with the phase change temperature recommended to be 2–4 °C higher than the average indoor operative temperature during the heating period. Specifically, 18 °C is optimal for Type I walls in Yinchuan, Beijing, and Dalian, while 15 °C is more appropriate for Type II walls in Shenyang and Harbin. The corresponding optimal thicknesses are 20 mm for Harbin, Shenyang, and Dalian; 30 mm for Yinchuan; and 40 mm for Beijing, achieving a balance between indoor temperature improvement and construction cost. (3) Operative temperature and discomfort hours are introduced to assess indoor thermal stability, especially in buildings with interior PCM plaster. Full article