Buildings, Volume 14, Issue 1 (January 2024) – 304 articles

To facilitate the precise design of earthquake-resistant structures, it is imperative to accurately evaluate the impact of seismic events on these constructions and predict their responses. OpenSeismoMatlab, a robust, free ground motion data processing software, plays a pivotal role in this endeavor. It empowers users to compute a wide array of outcomes using input acceleration time histories, encompassing time histories themselves, as well as linear and nonlinear spectra. These capabilities are instrumental in supporting structural design initiatives. This study provides a comprehensive exposition of the latest version (v 5.05) of OpenSeismoMatlab. It delves into intricate facets of the software, encompassing a detailed exploration of the input and output variables integral to each operational category. Comprehensive calculation flowcharts are presented to elucidate the software’s organizational structure and operational sequences. Furthermore, a meticulous verification assessment is conducted to validate OpenSeismoMatlab’s performance. This verification entails a rigorous examination of specific cases drawn from existing literature, wherein the software’s outcomes are rigorously compared against corresponding results from prior studies. The examination not only underscores the reliability of OpenSeismoMatlab but also emphasizes its ability to generate outcomes that closely align with findings documented in the established body of literature. Concluding the study, the paper outlines potential directions for future research, shedding light on avenues where further development and exploration can enhance the utility and scope of OpenSeismoMatlab in advancing seismic engineering and structural design practices. Full article

Cement has been widely used as a structural material in many underground projects, and these projects often face high- or ultra-high-temperature environments, leading to the deterioration of the mechanical, porosity, and permeability properties of set cement, thereby increasing the risk of instability of underground structures. In response to this, two new temperature-resistant cement slurry systems were designed. Experiments were conducted on the changes in porosity and permeability of set cement after thermal treatment using low-field nuclear magnetic resonance technology (NMR), visual studies of pore and crack development were carried out using the argon-ion polishing field emission scanning electron microscopy (FE-SEM) and computed tomography (CT) methods. The research results show that as the thermal treatment temperature continued to rise, the compressive strength first increased (25 °C–200 °C) and then decreased (200 °C–600 °C). The porosity of the set cement first decreased (25 °C–115 °C) and then increased (115 °C–600 °C), and the penetration first slowly increased (25 °C–400 °C) and then rapidly increased (400 °C–600 °C). Visualization experiments were conducted on micro-cracks and the pore distribution of the set cement under high- and ultra-high-temperatures, which proved the evolution law of these characteristic parameters. The research results have vital reference significance for the protection of the structural stability of cement components when encountering high-temperature environments. Full article

This study explores the potential use of new connections to shape precast building geometries, focusing on connection performance, robotic fabrication, and foldable structural elements. Three connection types, including coupled-bolts, hinges, and steel tubes, were initially proposed and assessed in beam and portal frame geometries. In contrast, the study introduces conceptual ideas; initial experimental and numerical studies were conducted to estimate connection capacities. Robotic fabrication for connecting elements to reused concrete and converting floor elements into beams was detailed, showcasing robotic technology’s performance and potential. These connections were employed in designing new precast element geometries, ranging from simple beams to multi-story buildings. Geometric properties and volume quantities of folded and opened geometries were studied using 37 CAD models. To properly discuss the joint performance reference, monolithic elements with exact dimensions were created for comparison. Despite varied connection capacity ($38\%$ to $100\%$), the steel tube exhibited the most desirable performance, resembling a monolithic element with an exact size. Some proposed foldable geometries showed a significant reduction (up to $7\%$) in element dimensions to facilitate transport and construction. Full article

Against the backdrop of China’s continuous promotion of green and low-carbon transformation and the development of construction industrialization, high-strength composite structural systems have significant development prospects. However, their research and application in the field of construction are insufficient. In response to this issue, the study proposes a new high-performance structural system, namely the composite frame–high-strength steel plate wall core tube resilient structural system, which includes a core tube composed of double steel plate concrete composite shear walls and replaceable energy dissipation coupling beams, as well as composite frames. The highest strength grades of the steel plate and concrete used in the composite walls of the core tube are Q550 and C100, respectively. Using a 200 m building as an example, this study designs and establishes models for this high-performance structure and a conventional reinforced concrete frame–core tube structure. Subsequently, the dynamic elastoplastic time history analysis and seismic resilience assessment of structures are conducted under design basis earthquakes (DBEs), maximum considered earthquakes (MCEs), and extremely rare earthquakes (EREs). Research has shown that, compared to conventional structures, the thickness of shear walls of new high-performance structures can be effectively reduced, which helps decrease the self-weight of the structure and improve the available space in buildings. Additionally, high-performance structures exhibit a better performance in controlling the story drift ratio, lower plastic damage and overall stiffness degradation of the structure, and better seismic performance. The seismic resilience of the high-performance structure has been significantly enhanced, especially in terms of minimizing casualties, thereby better ensuring the safety of people’s lives and property. Full article

In the construction domain, there is a growing emphasis on sustainability, resource efficiency, and energy optimisation. Light-gauge steel panels (LGSPs) stand out for their inherent advantages including lightweight construction and energy efficiency. However, the effective management of thermal efficiency, particularly addressing thermal bridges, is crucial. This paper conducts a detailed numerical investigation into the thermal performance of LGSPs, examining varied insulation ratios. Thermal finite element (FE) models were initially developed using the THERM software and validated against code predictions and results available in the literature. A comprehensive parametric study explored different insulation ratios, insulation materials, and wall thicknesses, discovering their impact on thermal transmittance (U-value). Key findings revealed that U-value correlated with insulation material conductivity, with E-PLA insulation exhibiting the lowest values, and increasing wall thickness resulted in decreased U-values. It was found that a strategic use of insulation yielded a U-value reduction of over 65%. New simplified design approaches were developed, featuring insulation ratios linked to accurate U-value predictions for LGSP configurations. The new design approaches were found to provide more accurate and consistent U-value predictions. Moreover, optimum insulation ratios for new builds and existing building extensions were found to be around 0.9 and 0.7 for 275 mm and 325 mm thick walls, respectively. These proposed energy-efficient solutions, facilitated through advanced design, are well-aligned with net-zero construction objectives. Full article

Data centers are energy-intensive facilities, with over 95% of their total cooling load attributed to the heat generated by information technology equipment (ITE). Various energy-saving techniques have been employed to enhance data center efficiency and to reduce power usage effectiveness (PUE). Among these, economizers using outdoor air for cooling are the most effective for addressing year-round cooling demands. Despite the simplicity of the load composition, analyzing data center cooling systems involves dynamic considerations, such as weather conditions, system conditions, and economizer control. A PUE interpretation tool was specifically developed for use in data centers, aimed at addressing the simplicity of data center loads and the complexity of system analysis. The tool was verified through a comparison with results from DesignBuilder implementing the EnergyPlus algorithm. Using the developed tool, a comparative analysis of economizer strategies based on the PUE distribution was conducted, with the aim of reducing the PUE of data centers across various climatic zones. The inclusion of evaporative cooling (EC) further improved cooling efficiency, leading to reductions in PUE by approximately 0.02 to 0.05 in dry zones. Additionally, wet zones exhibited PUE reductions, ranging from approximately 0.03 to 0.07, with the implementation of indirect air-side economizer (IASE). Sensitivity and uncertainty analysis were further conducted. The computer room air handler (CRAH) supply temperature and CRAH temperature difference were the most influential factors affecting the annual PUE. For the direct air-side economizer (DASE) and DASE + EC systems, higher PUE uncertainty was observed in zones 1B, 3B, 4B, and 5B, showing ranges of 1.17–1.39 and 1.15–1.17, respectively. In the case of the IASE and IASE + EC systems, higher PUE uncertainty was noted in zones 0A, 0B, 1A, 1B, and 2A, with ranges of 1.22–1.43 and 1.17–1.43, respectively. The distinctive innovation of the tool developed in this study is characterized by its integration of specific features unique to data centers. It streamlines the computation of cooling loads, thus minimizing the burden of input, and delivers energy consumption data for data center cooling systems with a level of precision comparable to that of commercial dynamic energy analysis tools. It provides data center engineers with a valuable resource to identify optimal alternatives and system design conditions for data centers. This empowers them to make informed decisions based on energy efficiency enhancements, thereby strengthening their ability to improve energy efficiency. Full article

The bullring of Ronda, one of the oldest in Spain, declared in 1993 as an Asset of Cultural Interest, occupies a paramount place among the buildings of its type thanks to its outstanding beauty. Its configuration as an open-air enclosure with a circular floor plan, as an evocation of the ancient Roman amphitheaters, and its interior with galleries on two levels that house the audience play a fundamental role in the acoustic energy decay and diffusion of the space. The link between architecture and acoustics of the Ronda bullring has been carried out by using on-site measurements and simulation techniques. To this end, an acoustic model is created, which is adjusted by taking the set of 3D impulse responses recorded on-site. The presence of the public and the various sound sources that exist during the bullfight itself are analyzed in the simulations, whereby the conditions of occupation and vacancy are compared, as are the variations due to the location of the sources. Finally, speech intelligibility conditions are simulated with a human directivity source. The precision of the virtual acoustic model enables the sound architecture of this singular space to be ascertained and preserved, thereby incorporating sound as an associated intangible heritage. Full article

As urbanization accelerates, deep excavation projects have become increasingly vital in the construction of high-rise buildings and underground facilities. However, the potential risks to the surrounding environment and the inherent complexities involved necessitate thorough research to ensure the safety of those engineering projects with deep foundation pit excavation and to minimize their impact on adjacent structures. This study introduces a multi-stage and multi-parameter numerical simulation method to scrutinize the construction process of deep foundation pits. This approach not only investigates the influence of excavation activities on nearby buildings and roads but also enhances the fidelity of simulation models by establishing a three-dimensional finite element model integrated with on-site investigated geological information. Therefore, the proposed method can provide a more holistic and accurate analysis of the overall impacts of the pit excavation process. To examine the feasibility and effectiveness of the proposed method, this study adopts the multi-stage and multi-parameter influence analysis approach for a real practical engineering case to explore the impact of excavation on the foundation pit support structure, nearby buildings, and surrounding roads. The foundation pit support’s maximum displacement was 8.64 mm, well under the 25 mm standard limit. Anchor rod forces were about 10% below the standard limit. Building and road settlements were also minimal, at 10.33 mm and 16.44 mm, respectively, far below their respective limits of 200 mm and 300 mm. This study not only validates the feasibility of design and construction stability of deep foundation pits but also contributes theoretical and practical insights, serving as a valuable reference for future engineering projects of a similar scope. Full article

In the EU, the building sector is responsible for 40% of the global energy consumption for final uses and 36% of the carbon dioxide (CO₂) emissions. Heat pumps allow for the replacement of conventional systems based on fossil fuels with the perspective of combining PV and solar thermal collectors. In order to rationalize the use of the solar source, this paper examined the self-consumption electricity share, the CO₂ equivalent emissions, and the domestic hot water demand covered by renewable sources which were determined in two opposite climatic conditions. These involved both electric and thermal storage systems and considered two different control strategies. The first is commonly used for the management of air-conditioning systems, the second was specifically conceived to maximize the exploitation of the solar source. Results showed that the latter significantly reduced grid dependence in both locations, determining the direct satisfaction of 76% of the thermal and electric loads through the PV self-consumption, determined by 18 kWp of installed PV and a battery capacity of 24 kWh. In terms of equivalent CO₂ emissions, when the two control strategies were compared, a remarkable reduction in emissions was registered for the latter, with percentages ranging between 8% and 36% as a function of PV surface and battery capacity. The analysis of domestic hot water supplies revealed disparities between the two localities: the colder first, relied more on heat pumps for water heating, while the warmer second, benefitted from the large availability of solar radiation. Full article

This study addressed the complex problems of selecting a constitutive model to objectively characterize asphalt mixtures and accurately determine their viscoelastic properties, which are influenced by numerous variables. Inaccuracies in model or parameter determination can result in significant discrepancies between the calculated and measured results of the pavement’s structural dynamic response. To address this, the research utilized the physical engineering principles of asphalt pavement structure to perform dynamic modulus tests on three types of high-content rubberized asphalt mixtures (HCRAM) within the surface layer. The research aimed to investigate the influencing factors of the dynamic modulus and establish a comprehensive master curve. This study also critically evaluated the capabilities of three viscoelastic models—the three-parameter solid model, the classical Maxwell model, and the classical Kelvin model—in depicting the dynamic modulus of HCRAM. The findings indicated a negative correlation between the dynamic modulus of the asphalt mixture and temperature, while a positive association exists between the loading frequency and temperature, with the impact of the loading frequency diminishing as the temperature increases. Notably, the three-parameter solid model was identified as the most accurate in describing the viscoelastic properties of the HCRAM. Furthermore, the dynamic response calculations revealed that most indexes in the surface layer’s dynamic response are highest when evaluated using the three-parameter viscoelastic model, underscoring its potential to enhance the pavement performance’s predictive accuracy. This research provides valuable insights into optimizing the material performance and guiding the pavement design and maintenance strategies. Full article

In order to alleviate the increasing serious urban waterlogging problem, the rainstorm resistance of a new self-compacting recycled pervious concrete (NSRPC) under the coupling of freeze–thaw (F-T) and fatigue is studied. The once-in-a-century rainfall was simulated, and the rainstorm resistance of NSRPC was evaluated mainly through the ponding depth and drainage time. In addition, the mechanical properties (compressive strength and flexural strength), mass loss rate and relative dynamic elastic modulus of NSRPC during F-T and fatigue coupling were measured. The microstructure of NSRPC was observed by scanning electron microscopy, and its deterioration mechanism was analyzed. The results show that the fatigue load aggravates the F-T damage of NSRPC in the later stage. With the increase in the number of fatigue cycles, the loss rate of compressive strength and flexural strength of NSRPC increases continuously, and the permeability coefficient decreases first and then increases. With the increase in the number of freeze–thaw and fatigue cycles, the mass loss rate increases gradually, and the relative dynamic elastic modulus decreases gradually. After the coupling of fatigue and F-T cycles, the minimum mass loss of NSRPC is only 2.14%, and the relative dynamic elastic modulus can reach 86.2%. The increase in the number of fatigue cycles promotes the generation and expansion of micro-cracks and provides more channels for water to invade the matrix. Under the action of rainstorm in the 100-year return period, the maximum ponding depth of NSRPC with steel fiber content is 84 mm, and the drainage time is 7.1 min, which meets the needs of secondary highway. This study will provide theoretical basis for improving the service life and drainage capacity of urban drainage pavement in cold areas. Full article

To study how varying the parameters of expansion joints and bearing supports (E-B parameters) affects the dynamic response of a coupled vehicle–bridge system for curved girder bridges, a dynamic response analysis method for the coupled vehicle–joint (bearing)–bridge system, which takes into account centrifugal forces, was proposed and verified. Subsequently, taking a continuous curved box girder bridge as the prototype, the influence of the E-B parameters on the vehicle-induced dynamic response of the curved girder bridge was explored. The results showed that the dynamic amplification factor (DAF) of the middle beam of the expansion joint (DAF-EJ) and the main girder of the curved bridge (DAF-MG) were both significantly influenced by the E-B parameters. When there were height differences between the middle beam and side beam in the EJ, the DAF-EJ obviously varied, and the DAF-MG increased. When the EJ was damaged, the impact effect of the vehicle on the bearing support increased. The DAF-EJ and DAF-MG both increased with the decrease of the vertical support stiffness of the bearing support. The DAF-EJ was greatly affected by the single-support void at the near-slit end of the lane. The DAF-MGs at the beam end, the 1/4 point and 1/2 point of the first span, and the 1/2 point of the second span, were significantly affected by the single-support void near the measuring point. Compared with the single-support void, the DAF-EJ and DAF-MG more significantly increased under the double-support void. Variation in the height difference of the EJ had a more significant effect on the DAF-EJ and DAF-MG at the beam end, while a vertical stiffness reduction in the bearing support had a more significant effect on the DAF-MG. Full article

Fatigue failure in asphalt pavements, caused by continuous loading, primarily occurs at the interface between the asphalt binder and the aggregate (adhesive failure) or within the asphalt binder itself (cohesive failure). This study conducted variable stress fatigue tests on asphalt binders to investigate the fatigue damage evolution mechanism that aligns most closely with actual road conditions. By altering test conditions such as stress amplitude and loading frequency, the study summarized the patterns of change in the fatigue performance parameters of binder samples and analyzed their fatigue life. The research methods employed are of significant value for refining the existing asphalt fatigue evaluation systems. Indicators such as dissipated energy ratio, cumulative dissipated energy ratio, rate of change in dissipated energy, and the G-R constant n × G_n* were used as criteria for fatigue failure. The fatigue life of samples under different stress levels was calculated, and the applicability of each dissipated energy fatigue indicator was evaluated. The evaluation indicators, like dissipated energy ratio and cumulative dissipated energy ratio, failed under large stress outside the non-linear viscoelastic range, whereas the rate of change in dissipated energy and the G-R constant n × G_n* accurately determined the fatigue life of samples in fatigue tests at all stress levels, covering a broader range of applicable stresses. In variable stress fatigue tests, the rate of change in dissipated energy and the G-R constant were used as indicators for determining fatigue failure. Under a small-to-large loading mode, the second stage of the sample’s fatigue life was too short, causing the G-R constant curve to not reach its peak, and hence it could not accurately determine the sample’s fatigue life. Under a large-to-small loading mode, there are sufficient loading cycles before fatigue failure occurs, allowing the G-R constant curve to reach its peak, demonstrating that the G-R constant remains applicable in this loading mode. Under both small-to-large and large-to-small loading modes, the fatigue failure point of the samples could be determined based on the rate of change in dissipated energy curve. It is recommended to use the rate of change in dissipated energy as the failure criterion for samples in variable stress fatigue tests on asphalt binders. Full article

To explore the performance evolution mechanism of SBS-modified bitumen (SMB) during construction and service, the chemical structure, molecular weight and properties of styrene–butadiene–styrene triblock copolymer (SBS) and SMB under multiple aging levels were assessed via Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC) and a dynamic shear rheometer (DSR). The results indicate that the polybutadiene segments in SBS are susceptible to oxidative degradation, and the molecular weight of SBS decreases rapidly during the aging process. The complex modulus and temperature sensitivity of SMB show relatively small changes during the early aging stage, which is mainly attributed to the impact of SBS oxidative degradation. While its temperature sensitivity decreases sharply after double PAV aging, it means the influence of asphalt aging on its performance is dominant. And there is a significant difference in the effect of aging on the creep recovery behavior of SMB under high and low shear stresses. The percentage recovery (R) of SMB decreases and then increases under low shear stress as aging progresses. While the value R of SMB increases gradually under high shear stress with the extension of aging. Meanwhile, the viscoelastic properties of SMB have gradually transformed to those of aged matrix asphalt after serious aging, which is also confirmed by the gradual destruction and degradation of the SBS cross-linked network in the binder from a fluorescence micrograph. This research will help to understand the performance failure mechanism of SMB during service, providing a theoretical reference for the selection of maintenance and renovation opportunities during the service process of SBS-modified asphalt pavement, as well as the avenue to achieve high-performance recycling. Full article

The production of steel rebar is an energy-intensive process that generates CO₂ emissions. In construction, waste is generated by cutting stock-length rebar to the required lengths. The reduction rate achieved in most previous studies was limited due to adherence to lap splice positions mandated by building codes and the use of stock-length rebar. A previous study demonstrated a significant reduction in rebar usage and cutting waste, approaching zero, upon optimizing the lap splice position, reducing the number of splices, and utilizing special-length rebar. However, the reference length used to determine the special-length rebar was not clearly optimized. This study proposes a special length priority optimization model to minimize wall rebar usage and waste by reducing the number of splices while simultaneously ensuring an optimal reference length. The proposed model was validated using a case study wall with a standard hook anchorage at the top of the wall reinforcement. The optimization model reduced rebar cutting waste to 0.18% and decreased rebar usage from the original design by 16.16%. Full article

In order to study the long-term bearing capacity of concrete pile composite foundation in the Salt Lake area, based on the Tehran Isfahan high-speed railway project in Iran, the full (semi) immersion drying test and rapid freeze-thaw test was carried out, and the specimens were scanned by electron microscope. Numerical calculations were used to study the effects of different pile strengths and design parameters on the long-term bearing capacity of the composite foundation. The main conclusions were as follows: The concrete specimens in the adsorption zone deteriorated earlier and faster. In the rapid freeze-thaw tests, the strength attenuation of high-strength (C40, C50) specimens was smaller than that of low-strength specimens (C20). Within 20 years after construction, the additional settlement of low-strength (C20) piles was 12.21 mm, while high-strength concrete was less affected by deterioration. With pile spacing ranging from 1.8 m to 4.5 m, the maximum increase in additional settlement under the C20 condition was about 20 mm. The pile-soil stress ratio under the three conditions increased by 2.42, 6.59, and 8.63. As the pile length and diameter increased, the peak stress of the pile body moved towards the pile end, and the changes in the pile-soil stress ratio under the three conditions were similar. Full article

Building operational energy alone accounts for 28% of global carbon emissions. A sustainable building operation promises enormous savings, especially under the increasing concern of climate change and the rising trends of the digitalization and electrification of buildings. Intelligent control strategies play a crucial role in building systems and electrical energy grids to reach the EU goal of carbon neutrality in 2050 and to manage the rising availability of regenerative energy. This study aims to prove that one can create energy and emission savings with simple weather and emission predictive control (WEPC). Furthermore, this should prove that the simplicity of this approach is key for the applicability of this concept in the built world. A thermodynamic simulation (TRNSYS) evaluates the performance of different variants. The parametrical study varies building construction, location, weather, and emission data and gives an outlook for 2050. The study showcases five different climate locations and reveals heating and cooling energy savings of up to 50 kWh/(m²a) and emission savings between 5 and 25% for various building types without harming thermal comfort. This endorses the initial statement to simplify building energy concepts. Furthermore, it proposes preventing energy designers from overoptimizing buildings with technology as the solution to a climate-responsible energy concept. Full article

The construction of reinforced concrete (RC) structures inevitably consumes an excessive number of rebars, leading to significant cutting waste and carbon emissions. Extensive research has been conducted to minimize this issue and its consequences; however, these methods consistently consume a substantial number of rebars. This includes a previous study that utilizes the lap splice position optimization and special-length rebar concept without considering the lapping zone regulation. Moreover, conventional lap splices pose inherent drawbacks that could jeopardize the structural integrity of RC members. In contrast, mechanical couplers eliminate the need for rebar lapping, effectively reducing rebar consumption. This research aims to evaluate the impact of an integrated mechanical coupler and special-length-priority minimization algorithm on the reduction in rebar consumption and cutting waste in RC columns, achieving near-zero cutting waste. To validate the effectiveness of the proposed algorithm, it was applied to the column rebars of an RC building. The results revealed a significant reduction in the ordered rebar consumption by 18.25%, accompanied by substantial reductions in the cutting waste (8.93%), carbon emissions (12.99%), and total costs (9.94%) compared with a previous study. The outcomes provide the industry with insights into further reducing rebar consumption and its related consequences. Applying the proposed algorithm to various construction projects will further amplify the corresponding benefits. Full article

Taking the high and large space of the University of Science and Technology Beijing Gymnasium as this research object, this paper analyzes the influence of different window positions, window-to-wall ratio (WWR), solar heat gain coefficient (SHGC), heat transfer coefficient (K), and visible light transmittance (VT) on the total indoor energy consumption in winter and summer and obtains the relationship between the daylight factor and VT formed when the window is opened per unit area. Through energy consumption simulation, the variation law and calculation formula for indoor total energy consumption are obtained. The results show that the SHGC and K of the exterior window have a significant influence on the total energy consumption. By using the energy consumption simulation of different types of exterior windows, it is concluded that the SHGC of the south-facing window is negatively correlated with the variation of air conditioning energy consumption per unit area Δe_1,w, while the others are positively correlated. Moreover, the SHGC and K of the skylight have the most significant influence on the Δe_1,w. The total energy consumption decreases and then increases with the increase in the window area, and there is a lowest point, so the right side of the lowest point is less than or equal to 105% of the lowest total energy consumption as a reasonable window area zone. Finally, a progressive optimization method for weighing daylighting and energy consumption in university gymnasiums in Beijing is proposed. Full article

The construction industry, despite its anticipated significant growth, has struggled with low productivity over the past two decades. Design for manufacturing and assembly (DfMA), a methodology with a history of success in other industries, presents a promising solution to enhancing efficiency in construction. This article reviews the current state of DfMA in the construction industry, identifies the most recent research themes in the field of DfMA, and provides recommendations for future DfMA research based on the existing research gaps. The paper employs a mixed-method approach, combining quantitative bibliometric analysis and qualitative thematic analysis. Using Scopus as the literature database, the study identified 43 relevant articles published between 2013 and 2023. The bibliometric analysis reveals a growing interest in DfMA research, with an upward trend in publications over the years. The thematic analysis categorizes DfMA research topics into six main themes: Innovation and Technology Trends, Sustainability and Environmental Impact, Regulatory and Policy Considerations, Collaborative Approach, Applications, Benefits, and Challenges, and Project Lifecycle. Each theme is explored in-depth, providing insights into the transformative impact of technology, environmental considerations in DfMA, regulatory challenges, collaborative strategies, varied applications, and the project lifecycle phases influenced by DfMA. The article concludes by presenting identified research gaps and offering recommendations for future DfMA research. It emphasizes the need for a holistic approach, continued collaboration, and a focus on unexplored aspects of regulatory frameworks and the entire project lifecycle. This study sets a new benchmark in DfMA research by employing a novel mixed-method approach and providing unprecedented insights into the multifaceted role of DfMA in advancing construction industry practices. It serves as a valuable resource for researchers, practitioners, and stakeholders in the construction industry by offering a comprehensive understanding of DfMA’s current state and guiding future research endeavors. Full article

The thermal comfort evaluation of the urban environment arouses widespread concern among scholars, and research in this field is mostly based on thermal comfort evaluation indexes such as PMV, PET, SET, UTCI, etc. These thermal comfort index evaluation models are complex in the calculation process and poor in operability, which makes it difficult for people who lack a relevant knowledge background to understand, calculate, and apply them. The purpose of this study is to provide a simple, efficient, and easy-to-operate outdoor thermal comfort evaluation model for severe cold areas in China using a machine learning method. In this study, the physical environment parameters are obtained by field measurement, and individual information is obtained by a field questionnaire survey. The applicability of four machine learning models in outdoor thermal comfort evaluation is studied. A total of 320 questionnaires are collected. The results show that the correlation coefficients between predicted values and voting values of the extreme gradient lifting model, gradient lifting model, random forest model, and neural network model are 0.9313, 0.7148, 0.9115, and 0.5325, respectively. Further analysis of the extreme gradient model with the highest correlation coefficient shows that individual factors (such as residence time, distance between hometown and residence, clothing, age, height, and weight) and environmental factors (such as air humidity (RH), wind speed (v), air temperature (Ta), and black bulb temperature (Tg)) have different influences on thermal comfort evaluation. In summary, using a machine learning method to evaluate outdoor thermal comfort is simpler, more direct, and more efficient, and it can make up for the lack of consideration of complex individual factors in the evaluation method of thermal comfort index. The results have reference value and application value for the research of outdoor thermal comfort evaluation in severe cold areas of China. Full article

This study investigates the hydration, microstructure, autogenous shrinkage, electrical resistivity, and mechanical properties of Portland cement pastes modified with PEG-PPG triblock copolymers with varied molecular weights. The early age properties including setting time and hydration heat were examined using the Vicat test and isothermal calorimetry. The hydration products and pore size distribution were analyzed using thermogravimetric analysis (TGA) and nitrogen adsorption, respectively. Mechanical properties and electrical resistivity were evaluated using the compressive strength test and electrochemical impedance spectroscopy (EIS). It was shown that the addition of the copolymers reduced the surface tension of the cement paste pore solution due to the presence of a hydrophobic block (PPG) in the molecular structure of the copolymers. The setting time and hydration heat were relatively similar in the control paste as well as the pastes modified with the copolymers. The results showed that copolymers were able to reduce the autogenous shrinkage in the paste due primarily to a reduction in pore solution surface tension. TGA showed a slight increase in the hydration degree of the paste modified with the copolymers. The compressive strength was reduced in the pastes modified with the copolymers that showed an increased volume of air voids. The addition of copolymers did not affect the electrical resistivity of the pastes except in the case where there was a large volume of air voids, which acted as electrical insulators. Full article

In this investigation, a U-shaped connection (U-C) was introduced for a prefabricated steel plate shear wall with beam-only connections. This design replaces a portion of shear bolts with tension bolts to enhance bolt efficiency and reduce the overall bolt count, and it is suitable for a prefabricated high-rise steel structure. Four 1/3 scale specimens were designed, and an array of performance aspects including failure modes, hysteretic behavior, skeleton curves, energy dissipation capacity, stiffness degradation, and key performance indicators were systematically investigated through a combination of quasi-static tests and finite element analyses. The results showed that the combination arrangement of tensile and shear bolts in U-C effectively reduced the usage of bolts used and reduced installation costs; under low cycle reciprocating loads, the ultimate bearing capacity and energy dissipation capacity of a beam-only-connected prefabricated steel plate shear wall with U-shaped connection (BPSW-U) had slightly decreased compared with the prefabricated steel plate shear wall with discontinuous cover-plate connection (DCPC). Nevertheless, the BPSW-U excelled in preserving the integrity of the frame beams, channeling structural plastic deformations primarily into the infilled steel plate. This design feature ensures that post-earthquake functionality recovery can be achieved by simply replacing the infilled steel plate. Full article

Building construction accounts for a significant proportion of global greenhouse gas emissions, raw material extraction, and waste production. Applying circular economy (CE) principles in the building construction industry would considerably reduce these values. However, uptake by the industry is relatively slow, which is largely attributed to sectoral barriers, including limitations in knowledge and experience. This review paper aims to assess and contribute to diminishing these obstacles by offering a comprehensive review of circular material usage principles and strategies within the construction sector. Opportunities and facilitators of change are also presented, including innovations and emerging technologies in recycling, digitization, robotic systems, novel materials, and processing. Finally, four case studies demonstrate the application of circular theory via a novel block system, recycled aggregate, modular kitchen reuse, and an energy efficiency retrofit. The conclusions show that future efforts should prioritize the development of strong regulatory frameworks, awareness initiatives, and international cooperation. In this regard, the integration of technological advancements, such as AI, robotics, and blockchain, is essential for optimizing waste management efficiency. Furthermore, education on circular practices plays a critical role. Through global collaboration, standardizing circular construction approaches can promote a more sustainable and resilient building construction industry. Full article

The design of the enclosure layout is crucial in establishing a comfortable wind environment in Chinese classic landscape gardens. The Ruins Park of the Old Summer Palace exemplifies the mountain construction techniques used in classical Chinese flat gardens, with a diverse and illustrative spatial layout of the hills. In this study, we focused on the earthen hill space of the Old Palace in the Summer Palace Ruins Park. We compared and analyzed the effects of different enclosure layouts of earthen hill spaces on the summer monsoon wind environment. This was achieved via on-site measurements and simulations using computational fluid dynamics (CFD). The results show the following: (1) The direction index of the enclosure layout of the earthen hill space affects wind speed, comfort, and ventilation. Increasing the index reduces speed and comfort but improves ventilation. (2) Increasing the density index of the enclosure layout of the earthen hill space leads to a decrease in wind speed and wind comfort and improved ventilation. (3) Conversely, increasing the area index of the enclosure layout of the earthen hill space results in an increase in wind speed, which can result in better wind comfort but can also lead to poor ventilation. Overall, the results suggest that careful consideration should be given to the enclosure layout of landscape gardens to ensure optimal wind conditions within the space. Full article

Quality quartz sand is globally utilized in construction due to its availability and economic factors, especially in the production of composite cements. Despite its positive properties, quartz sand also has several disadvantages. The dilation of quartz sand can be technologically significant for certain high-temperature applications. This dilation has a non-continuous character with sharp volume change caused by the phase transformation from β to α SiO₂ at temperatures around 573 °C. The extent of dilation depends on various factors such as compaction, grain size, the quantity of sand, as well as the shape and character of the grain and chemical purity, particularly the SiO₂ content. In this study, six types of quartz sand from different locations in Central Europe were examined, and the influence of chemical composition and grain shape was correlated with the final dilation of these samples. Evaluation methods included X-ray fluorescence spectroscopy (XRFS), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), differential thermal analysis (DTA), and linear thermal expansion analysis. It was found that angular grains, despite their chemical purity, may exhibit minimal dilation. Conversely, the least suitable combination in terms of dilation appears to be a high SiO₂ content and high roundness of grains with a smooth surface. Full article

Contracting parties in construction projects confront significant challenges due to changes. This is an inherent industry characteristic. Managing changes properly with the help of a taxonomy encompassing many of the causes of changes can have a longitudinal and positive effect on project performance, knowledge management, and stakeholder management. However, studies to date have failed to propose an in-depth taxonomy for change causes in construction projects. Therefore, a taxonomy for change causes that can be applied to different construction projects has been developed. First, a systematic literature review and desk study sessions were conducted to identify the initial list of the taxonomy components. Six case studies were then analyzed to reveal the change causes of these cases. Based on the extracted change causes from the literature review and case studies, a taxonomy was developed by conducting focus group discussions with six experts. In the next step, the applicability and validity of the refined taxonomy were evaluated through face-to-face interviews. As a result, a taxonomy with a three-level hierarchy was proposed. This taxonomy is divided into three levels with 13 main categories, 50 subcategories, and 52 change causes. The proposed taxonomy is expected to contribute to practice by reducing the frequency of changes through proactive management of potential changes and standardizing knowledge management practices for managing change. Full article

A hanok is a traditional Korean house built with wood as the main structural material. It is constructed using cross- and unidirectional joint techniques without the use of steel. A hanok is composed of vertical and horizontal members, with columns being the most important vertical members and Daedeulbo being the most important horizontal member. As a cultural heritage structure, a hanok is often deformed due to damage to the wood over the years. In particular, the building beginning to lean is a typical example. Depending on the extent of damage, hanoks are repaired through partial or complete dismantling, but the same phenomenon recurs in many hanoks even after repair. In this study, 69 hanoks with well-documented records were selected to build a building column arrangement DB, column movement DB, and building attribute DB. The constructed DB was optimized in two dimensions by utilizing the features of each element with the UMAP algorithm and then clustered using the DBSCAN algorithm. Using this method, the movement of one column was analyzed individually, and the movement of two, three, and four columns was analyzed in groups, considering the characteristics of a hanok. As a result, similar patterns of column movement were found in hanoks with similar shapes. It was also possible to identify vulnerable locations according to the direction of column movement, and it was found that the deterioration of the joining strength of horizontal members affects the movement of columns. Full article

The main objective is to propose a calculation method for assessing the benefits of individual domestic prosumers in self-consumption and economic savings when managing their own energy resources. The paper applies the demand-side management concept in the residential sector from the individual domestic perspective so that customers can understand the value of their own sustainable energy resources, conducting self-generation and demand management. The novelty lies in allowing the prosumer to manage their own energy resources to their benefit at a reasonable cost, instead of participating in automated large residential demand-side-management programmes that respond to the means of the grid system operator or other energy service companies, such as aggregators. A methodology for calculating the self-consumption rate and the economic benefit for the consumer is proposed, including three different cases: consumer demand is higher than self-generation, and consumer demand is equal to self-generation, and consumer demand is lower than self-generation. The methodology is validated with actual data from a household in Valencia (Spain) during a complete year, obtaining an average reduction in the annual electricity bill of 70% and a demand coverage with the self-renewable system reaching values of 80% throughout the year. The significance of this methodology goes beyond the economic revenue of the individual consumer; it also aims to guide consumers towards efficient practices in the use of their available energy resources and raise awareness on their energy behaviour. Full article

The use of modular steel construction (MSC) achieves a minimum of on-site work and the potential for removability and reuse. In order to realize the overall disassembly of module buildings and the rapid off-site reconstruction after disassembly, special requirements are put forward for the joints of MSCs. The existing joints of MSCs have some problems, such as the difficulty in the erection of the joints for middle column connection and their inability to be reused. In order to solve these key technical problems, an improved version of the demountable self-locking joint is proposed based on the previous plug-in self-locking joint. For this new type of joint, a full-scale test consisting of four specimens was carried out. The results of functional tests verify that the joint has good demountability. The seismic behavior of the joint under seismic load was investigated by cyclic loading tests. Then, finite element (FE) models were developed and validated through the test results. The results of finite element parameter analysis show that joint boxes are very important to the initial stiffness of this kind of joint, but the thickness of the joint box and the diameter of the stud have little influence on the seismic behavior of the joint. Full article