Buildings

17 pages, 6070 KiB

Open AccessArticle

Investigation into the Early Cracking Behavior of High-Geothermal Tunnel Lining Concrete Based on Thermal–Mechanical Coupling Model

by Si Xie, Dan Zhao, Peng Yi, Qian Chen and Wei Liu

Buildings 2025, 15(2), 301; https://doi.org/10.3390/buildings15020301 - 20 Jan 2025

Viewed by 465

Abstract

As a typical extreme environment, a high-geothermal environment poses severe challenges to tunnel construction in western China. In this paper, a thermal–mechanical coupling model was formulated to evaluate the cracking behavior of lining under high-geothermal conditions, considering the early property evolution of concrete. [...] Read more.

As a typical extreme environment, a high-geothermal environment poses severe challenges to tunnel construction in western China. In this paper, a thermal–mechanical coupling model was formulated to evaluate the cracking behavior of lining under high-geothermal conditions, considering the early property evolution of concrete. This was further validated by field monitoring and analyzed by adjusting the relevant parameters. Results indicate that the higher cracking risk occurred on the external surface of the lining sidewall after 24 h of casting. With the increase in surrounding rock temperature, the duration of cracking risk in the lining was extended. When the surrounding rock temperature exceeded 68.7 °C, thermal insulation measures were required for the lining structure. Notably, superior thermal insulation was achieved by applying a sandwich structure of rigid polyurethane materials with a thickness of 20–60 mm. In terms of curing conditions, adopting formwork with a larger heat convection coefficient was conducive to reducing the cracking risk of the tunnel lining, with an appropriate removal time of 48 h. This work provides insights into the thermal–mechanical behavior of lining concrete, thereby mitigating its early cracking in a high-geothermal environment. Full article

(This article belongs to the Special Issue Research on the Construction Mechanical Behavior and Deformation Characteristics of Lining Structure—2nd Edition)

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18 pages, 246 KiB

Open AccessArticle

The Patronization of Pluvial Flood Risk and Adaptation Among Tenant-Owned Housing Associations in Sweden

by Mattias Hjerpe, Erik Glaas and Sofie Storbjörk

Buildings 2025, 15(2), 300; https://doi.org/10.3390/buildings15020300 - 20 Jan 2025

Viewed by 428

Abstract

Pluvial floods are increasingly affecting urban areas worldwide. Despite growing media attention and clear owner responsibility for reducing climate-related risk for buildings in Swedish national adaptation policy, adaptation action remains slow. Understanding how different property owner categories view and act on flood risks [...] Read more.

Pluvial floods are increasingly affecting urban areas worldwide. Despite growing media attention and clear owner responsibility for reducing climate-related risk for buildings in Swedish national adaptation policy, adaptation action remains slow. Understanding how different property owner categories view and act on flood risks is key for developing better incentive structures and support for accelerating adaptation action. While tenant-owned housing is a common form of housing tenure in Sweden, studies are lacking. This study enhances understanding of pluvial flood risk and adaptation views and actions by tenant-owned housing associations in two Swedish cities. It is based on assessments of 69 apartment buildings within eleven tenant-owned associations and semi-structured interviews with their eleven chairpersons. The study indicates that tenant-owned associations grossly underestimate their flood risks and responsibilities for climate adaptation, even though many buildings studied are at significant risk, and most associations have been impacted by floods, some severely and recurrently. The patronization of flood risk and responsibility for adaptation is attributed to several factors: underestimating risks and consequences, devaluing the benefit of one’s own adaptation actions, lacking knowledge about climate adaptation measures for buildings, and (overly) generous insurance terms. The findings confirm low adaptation action among housing associations, even those with recurring floods, which is concerning given the strong reliance on property-owner adaptation in national adaptation policy. Full article

(This article belongs to the Special Issue Enhancing Building Resilience Under Climate Change)

27 pages, 3003 KiB

Open AccessArticle

Research on the Carbon Reduction Potential of the Life Cycle of Building Roofs Retrofit Designs

by Dawei Mu, Wenjin Dai, Yixian Zhang, Yixu Shen, Zhi Luo and Shurui Fan

Buildings 2025, 15(2), 299; https://doi.org/10.3390/buildings15020299 - 20 Jan 2025

Viewed by 483

Abstract

This study examines existing buildings in Haikou in China under tropical island climate conditions. It presents three retrofit design models for greenhouses roofs (GHR), green roofs (GR) and photovoltaic roofs (PVR). The carbon cost of each retrofit roof model is calculated in the [...] Read more.

This study examines existing buildings in Haikou in China under tropical island climate conditions. It presents three retrofit design models for greenhouses roofs (GHR), green roofs (GR) and photovoltaic roofs (PVR). The carbon cost of each retrofit roof model is calculated in the production and transportation phases of building materials, construction, and demolition. The changes in electricity consumption, water consumption, and plant carbon reduction are coupled to calculate the carbon reduction generated by each phase of the use of the retrofitted roofs. The carbon reduction per unit area for GHR, GR and PVR over the life cycle (20 years) is then comprehensively calculated. The life cycle carbon reduction per unit area is 262.57 kg·m⁻² for GHR, 127.41 kg·m⁻² for GR and 2567.12 kg·m⁻² for PVR. Among the three retrofit methods, PVR has the greatest potential for reducing carbon emissions. The study can as a guide for implementing carbon reduction measures in tropical island areas. Domestic research on rooftop greenhouses also focuses on technology, yield, and energy consumption, mostly for northern regions with cold winters, and less research on rooftop greenhouses applied to regions with hot summers and warm winters. But domestic and foreign studies on the potential of rooftop greenhouses to reduce emissions have not yet been combined with plant cultivation of hydroelectric carbon emissions and plant carbon sequestration. Full article

(This article belongs to the Special Issue Indoor Climate and Energy Efficiency in Buildings)

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19 pages, 3610 KiB

Open AccessArticle

Multi-Scale Building Load Forecasting Without Relying on Weather Forecast Data: A Temporal Convolutional Network, Long Short-Term Memory Network, and Self-Attention Mechanism Approach

by Lanqian Yang, Jinmin Guo, Huili Tian, Min Liu, Chang Huang and Yang Cai

Buildings 2025, 15(2), 298; https://doi.org/10.3390/buildings15020298 - 20 Jan 2025

Viewed by 475

Abstract

Accurate load forecasting is of vital importance for improving the energy utilization efficiency and economic profitability of intelligent buildings. However, load forecasting is restricted in the popularization and application of conventional load forecasting techniques due to the great difficulty in obtaining numerical weather [...] Read more.

Accurate load forecasting is of vital importance for improving the energy utilization efficiency and economic profitability of intelligent buildings. However, load forecasting is restricted in the popularization and application of conventional load forecasting techniques due to the great difficulty in obtaining numerical weather prediction data at the hourly level and the requirement to conduct predictions on multiple time scales. Under the condition of lacking meteorological forecast data, this paper proposes to utilize a temporal convolutional network (TCN) to extract the coupled spatial features among multivariate loads. The reconstructed features are then input into the long short-term memory (LSTM) neural network to achieve the extraction of load time features. Subsequently, the self-attention mechanism is employed to strengthen the model’s ability to extract feature information. Finally, load forecasting is carried out through a fully connected network, and a multi-time scale prediction model for building multivariate loads based on TCN–LSTM–self-attention is constructed. Taking a hospital building as an example, this paper predicts the cooling, heating, and electrical loads of the hospital for the next 1 h, 1 day, and 1 week. The experimental results show that on multiple time scales, the TCN–LSTM–self-attention prediction model proposed in this paper is more accurate than the LSTM, CNN-LSTM, and TCN-LSTM models. Especially in the task of predicting cooling, heating, and electrical loads on a 1-week scale, the model proposed in this paper achieves improvements of 16.58%, 6.77%, and 3.87%, respectively, in the RMSE indicator compared with the TCN-LSTM model. Full article

(This article belongs to the Section Building Energy, Physics, Environment, and Systems)

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36 pages, 34796 KiB

Open AccessArticle

Semantic and Syntactic Dimensional Analysis of Rural Wooden Mosque Architecture in Borçka

by Birgül Çakıroğlu, Reyhan Akat, Evren Osman Çakıroğlu and Taner Taşdemir

Buildings 2025, 15(2), 297; https://doi.org/10.3390/buildings15020297 - 20 Jan 2025

Viewed by 593

Abstract

Religion is one of the most important factors in architectural shaping. The concepts or sub-concepts that make up religion have a different language that each designer wants to explain. This language is presented semantically and syntactically through the architect and the user interprets [...] Read more.

Religion is one of the most important factors in architectural shaping. The concepts or sub-concepts that make up religion have a different language that each designer wants to explain. This language is presented semantically and syntactically through the architect and the user interprets this fiction mostly with its syntactic dimension. The findings of this study provide valuable insights into modern mosque design by establishing a connection between belief systems and architectural expressions. Moreover, the study contributes to heritage preservation efforts by proposing a framework that links historical values to contemporary practices. In this study, it is aimed to analyze the effects of the belief concepts in the Islamic religion by analyzing the semantic and syntactic dimensions in rural wooden mosque architecture. Starting from the assumption that abstract values have a language in shaping, the principle of semiotics was utilized to reach concrete results. How the concepts and principles are determined in the semantic and syntactic dimensions of semiotics are explained. In the examination of the semantic dimension, 5 concepts from the concepts of belief in the Islamic religion, namely wahdaniyet, survival, knowledge, powerand hereafter, were discussed. The syntactic dimension was analyzed under basic design principles. The semantic and syntactic dimensions of the sample wooden mosques were analyzed, interpretedand analyzed through architectural drawings, interiorand exterior visuals. These analyses provide practical strategies for translating abstract religious principles into tangible design elements, enhancing their applicability in both educational and professional contexts. As a result, the concepts that emerged in the analyzed examples and the indicators of the sub-concepts belonging to these concepts were presented. It is suggested that the determined analysis model can contribute to design education in design departments and provide convenience to designers and researchers. The model also serves as a tool for creating mosque designs that respect cultural identity while addressing contemporary needs. This research is important in terms of being a reference for the concrete expression of the concepts that we cannot see in architectural formations but we can feel that they exist. Full article

(This article belongs to the Special Issue Design, Construction and Maintenance of Underground Structures)

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19 pages, 9163 KiB

Open AccessArticle

Investigating Fire Collapse Early Warning Systems for Portal Frames

by Ming Xie, Fangbo Xu, Zhangdong Wang, Li’e Yin, Xiangdong Wu, Mengqi Xu and Xiang Li

Buildings 2025, 15(2), 296; https://doi.org/10.3390/buildings15020296 - 20 Jan 2025

Viewed by 380

Abstract

In recent years, firefighter accidents and people injured by the collapse of steel structures during a fire have occurred frequently, which has attracted the attention of the National Emergency Management Department and the Fire and Rescue Bureau. It is urgent to carry out [...] Read more.

In recent years, firefighter accidents and people injured by the collapse of steel structures during a fire have occurred frequently, which has attracted the attention of the National Emergency Management Department and the Fire and Rescue Bureau. It is urgent to carry out research on early warning systems for building collapse during a fire. Existing early warning methods mainly use characteristic parameters such as temperature, vibration, and structural deformation. Due to the complexity of an actual fire, it is difficult to accurately predict the critical temperature of fire−induced instability in columns and the failure mode after the instability, and there are deviations in the collapse warnings. In this study, changes in ultrasonic transverse and longitudinal wave velocities at high temperatures are used to monitor the stiffness degradation of columns in fire in real time and improve the accuracy of early warning systems. In this study, four common collapse modes of portal frames are obtained by using the results of parametric numerical analysis. According to key displacements and the displacement rates of simple key measuring points, the elastic modulus threshold of a three−level early warning for portal frame collapse with different collapse modes is obtained. Combined with an ultrasonic experiment, the theoretical relationships between the transverse and longitudinal wave velocities and the elastic modulus of steel at high temperatures are verified, and the relationship between the transverse and longitudinal wave velocities and the overall damage of the portal frame is further constructed; then, a new early warning method for portal frame stability during a fire is proposed. Based on the change in wave velocity, a three-level early warning index for predicting portal frame stability during a fire is determined. When the collapse mode of a portal frame is an overall inward collapse, transverse and longitudinal wave velocities are reduced to 2635 m/s and 5308 m/s, respectively. At a second-level warning, they are reduced to 2035 m/s and 4176 m/s, respectively. At 1504 m/s and 3030 m/s, respectively, third-level warnings are issued. This research shows that the real−time monitoring of wave velocities provides an effective way for early warning systems to identify structural collapse. The proposed early warning method can be used as a quick and efficient early warning system for the collapse of portal frames during a fire, and its accuracy and applicability are verified by experiments. Full article

(This article belongs to the Section Building Structures)

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27 pages, 15338 KiB

Open AccessArticle

Post-Occupation Evaluation of Industrial Heritage Transformation into a Mixed-Mode Park Within the Context of Urban Renewal: A Case Study of Hebei, China

by Xiaowei Chen, Yijing Chen and Yuchen Liu

Buildings 2025, 15(2), 295; https://doi.org/10.3390/buildings15020295 - 20 Jan 2025

Viewed by 806

Abstract

In recent years, the in-depth implementation of China’s “shifting from secondary industries to tertiary industries” policy, coupled with the accelerating pace of urban renewal, has positioned the transformation and reuse of industrial heritage as a pivotal approach to enhancing urban spatial quality and [...] Read more.

In recent years, the in-depth implementation of China’s “shifting from secondary industries to tertiary industries” policy, coupled with the accelerating pace of urban renewal, has positioned the transformation and reuse of industrial heritage as a pivotal approach to enhancing urban spatial quality and fostering cultural continuity. This paper focuses on three mixed-mode industrial heritage transformation parks in Hebei Province: Dahua, Miansan, and Shimeiji. Based on existing research and practical circumstances, an evaluation system encompassing six dimensions and 18 indicators is established. On this basis, a questionnaire survey was conducted, including two parts: a satisfaction questionnaire and a Kano model questionnaire. According to the obtained data, the use of the park after completion was evaluated and the existing problems of the mixed-mode industrial heritage renovation park were summarized comprehensively. The research finds out the shortcomings of the commonalities and differences of mixed-mode industrial heritage parks, finally putting forward optimization suggestions for the problems, in order to provide theoretical reference and practical guidance for the renovation projects of the same type of industrial heritage in the urban renewal stage. Full article

(This article belongs to the Special Issue New Era of Urban Regeneration: Theories and Approaches from Diverse Aspects)

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17 pages, 6244 KiB

Open AccessArticle

Modeling and Seismic Performance Analysis of Grid Shear Walls

by Weijing Zhang, Caiwang Li and Xiao Chu

Buildings 2025, 15(2), 294; https://doi.org/10.3390/buildings15020294 - 20 Jan 2025

Viewed by 455

Abstract

Prefabricated insulation grid shear walls are a new type of wall which integrates structure, insulation and formwork. A grid-like reinforced concrete shear wall with vertical and transverse limbs is formed by casting concrete into the reserved vertical and transverse hollow cavities in the [...] Read more.

Prefabricated insulation grid shear walls are a new type of wall which integrates structure, insulation and formwork. A grid-like reinforced concrete shear wall with vertical and transverse limbs is formed by casting concrete into the reserved vertical and transverse hollow cavities in the prefabrication of cement polystyrene granular concrete wall formworks. In this paper, based on an earthquake engineering simulation open system (OpenSees), a new modeling approach for grid shear walls is proposed, and nonlinear analysis of two grid walls with different grid sizes under cyclic load is carried out. The accuracy and effectiveness of the grid shear wall model are verified by comparison of the predicted hysteretic response and experimental results. On this basis, the seismic performance of grid shear walls with different parameters (axial load ratio, vertical reinforcement ratio, transverse reinforcement ratio and transverse limb height) is analyzed. The results show that both axial load ratio and vertical reinforcement ratio can significantly improve the load capacity of grid shear walls. However, with an increase in the axial load ratio, the ductility of the grid shear walls decreases. The influence of transverse reinforcement ratio and transverse limb height on the load capacity of shear wall with large shear span ratio is relatively small, mainly because the failure mode of shear wall with large shear span ratio is bending failure. Based on parameter influence analysis, design suggestions for reinforcement ratio in vertical and horizontal limbs and the height of the transverse limb of grid shear walls are put forward. The research in this paper provides a reference for the application of grid shear walls in engineering. Full article

(This article belongs to the Special Issue Research on the Seismic Performance of Reinforced Concrete Structures)

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21 pages, 2397 KiB

Open AccessArticle

Exploration of Resident Satisfaction and Willingness in the Renovation of a Typical Old Neighborhood

by Wenjun Peng, Yanyan Huang, Changquan Li and Yilin Wang

Buildings 2025, 15(2), 293; https://doi.org/10.3390/buildings15020293 - 20 Jan 2025

Viewed by 662

Abstract

The reconstruction of old communities makes an outstanding contribution to, and holds practical significance for, livelihoods and ecological civilization in the urban renewal context. Clarifying the renovation intentions of residents is conducive to the effective implementation of reconstruction projects. This paper takes a [...] Read more.

The reconstruction of old communities makes an outstanding contribution to, and holds practical significance for, livelihoods and ecological civilization in the urban renewal context. Clarifying the renovation intentions of residents is conducive to the effective implementation of reconstruction projects. This paper takes a typical old neighborhood in Wuhan as an example to survey residents’ living satisfaction and renovation intention. Multiple linear regression analysis, factor analysis, and correlation analysis were used to quantitatively screen, judge, and process sample data. The results show that residents’ living satisfaction and willingness to renovate were different under the dimensions of resident age and property rights, respectively. Most residents were dissatisfied with the living state of the neighborhood. Residents over 61 years old or those who held real estate certificates had a strong willingness to renovate and tended to accept a unified management manner after the renovation of the old neighborhood. Moreover, resident satisfaction with the internal road traffic, infrastructure, and building state significantly affected the residents’ overall satisfaction with the living environment in the old neighborhood, which should be given more attention to improve the residents’ willingness to support the renovation items. Furthermore, it was found that resident satisfaction with building conditions, infrastructure, internal road traffic, and public environment significantly impacted their agreement with the renovation in the old neighborhood. This investigation could provide a basis and guidance for the reconstruction and design of old communities. Full article

(This article belongs to the Section Architectural Design, Urban Science, and Real Estate)

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26 pages, 31486 KiB

Open AccessArticle

Assessing and Enhancing Green Quantity in the Open Spaces of High-Density Cities: A Comparative Study of the Macau Peninsula and Monaco

by Jitai Li, Fan Lin, Yile Chen and Shuai Yang

Buildings 2025, 15(2), 292; https://doi.org/10.3390/buildings15020292 - 20 Jan 2025

Viewed by 453

Abstract

Green open space in high-density cities has positive significance in terms of improving the quality of the living environment and solving problems such as “urban diseases”. Taking the high-density urban districts of the Macau Peninsula and Monaco as examples, this study divides the [...] Read more.

Green open space in high-density cities has positive significance in terms of improving the quality of the living environment and solving problems such as “urban diseases”. Taking the high-density urban districts of the Macau Peninsula and Monaco as examples, this study divides the planning index of open space green quantity into two dimensions: the blue-green spaces occupancy rate (BGOR) within urban land areas and the blue-green spaces visibility rate (BGVR) of the main streetscape. Using satellite remote-sensing maps, GIS databases, and street-view images, this study evaluates the current green quantity in both regions and compares them to identify best practices. This study aims to assess and enhance the green quantity found in the open spaces of high-density cities, using the Macau Peninsula and Monaco as case studies. The primary research questions are as follows: (1) How can the green quantity in open spaces be effectively measured in high-density urban environments? (2) What planning strategies can be implemented to increase the green quantity and improve the urban living environment in such areas? Therefore, this study proposes planning strategies such as three-dimensional greening, converting grey spaces to green spaces, and implementing policies to encourage public participation in greening efforts. These strategies aim to enhance the green quantity in open spaces, thereby improving the urban living environment in high-density cities like Macau and providing a reference for similar urban areas in the world. Full article

(This article belongs to the Special Issue Research towards the Green and Sustainable Buildings and Cities)

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31 pages, 20925 KiB

Open AccessArticle

Seismic Performance and Flexural Capacity Analysis of Embedded Steel Plate Composite Shear Wall Structure with Fiber-Reinforced Concrete in the Plastic Hinge Zone

by Junlong Li, Guoqiang He and Jianbo Tian

Buildings 2025, 15(2), 291; https://doi.org/10.3390/buildings15020291 - 20 Jan 2025

Viewed by 487

Abstract

Due to its high axial bearing capacity and good ductility, the embedded steel plate composite shear wall structure has become one of the most widely used lateral force-resisting structural members in building construction. However, bending failure is prone to occur during strong earthquakes, [...] Read more.

Due to its high axial bearing capacity and good ductility, the embedded steel plate composite shear wall structure has become one of the most widely used lateral force-resisting structural members in building construction. However, bending failure is prone to occur during strong earthquakes, and the single energy dissipation mechanism of the plastic hinge zone at the bottom leads to the concentration of local wall damage. To improve the embedded steel plate composite shear wall structure, the plastic hinge zone of the composite shear wall is replaced by fiber-reinforced concrete (FRC) and analyzed by ABAQUS finite element simulation analysis. Firstly, the structural model of the embedded steel plate composite shear wall structure with FRC in the plastic hinge zone is established and the accuracy of the model is verified. Secondly, the effects of steel ratio, longitudinal reinforcement ratio, and FRC strength on the bearing capacity of composite shear walls are analyzed by numerical simulation. Finally, a method for calculating the embedded steel plate composite shear wall structure with FRC in the plastic hinge zone is proposed. It is shown that the displacement and load curves and failure modes of the model are basically consistent with the experimental results, and the model has high accuracy. The axial compression ratio and FRC strength have a great influence on the bearing capacity of composite shear walls. The calculation formula of the normal section bending capacity of the embedded steel plate composite shear wall structure with FRC in the plastic hinge zone is proposed. The calculated values of the bending capacity are in good agreement with the simulated values, which can provide a reference for its engineering application. Full article

(This article belongs to the Section Building Structures)

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19 pages, 3115 KiB

Open AccessArticle

OnlineLino—A Website on Architect Raul Lino’s Built Heritage at Médio Tejo, in Portugal

by Anabela Moreira, Inês Serrano, Paulo Santos, Regina Delfino, Pedro Matos, Ana Gracio and Ana Xavier

Buildings 2025, 15(2), 290; https://doi.org/10.3390/buildings15020290 - 20 Jan 2025

Viewed by 459

Abstract

The cultural context and values of twentieth-century architecture and construction confirm the need to preserve them for future generations, given the multiple challenges to overcome. Raul Lino da Silva (1879–1974) is a celebrated Portuguese architect who worked throughout the twentieth century and whose [...] Read more.

The cultural context and values of twentieth-century architecture and construction confirm the need to preserve them for future generations, given the multiple challenges to overcome. Raul Lino da Silva (1879–1974) is a celebrated Portuguese architect who worked throughout the twentieth century and whose architectural legacy is scattered from the north to the south of the country. The aim of this paper is to present the development of the website OnlineLino, which is related to the architectural and construction heritage of Raul Lino in the Médio Tejo region, an inland Portuguese territory with low demographic density. This work is focused on integrating documentary information dispersed across different digital funds, by aggregating it on a website that will be made available for public access in the future. To this end, data were collected from different funds, and the information was aggregated and systematised so that it could be included in the digital database developed, the OnlineLino website. The work was carried out by a multidisciplinary team in an academic setting, involving the areas of architecture, civil engineering, computer engineering and design. We hope that this website will contribute to the dissemination of Raul Lino’s architectural legacy, especially for buildings that are less studied and known. Full article

(This article belongs to the Special Issue Selected Papers from the REHABEND 2024 Congress)

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18 pages, 1977 KiB

Open AccessArticle

Exploring Critical Factors Influencing the Resilience of the Prefabricated Construction Supply Chain

by Tianyang Liu, Li Ma and Hongwei Fu

Buildings 2025, 15(2), 289; https://doi.org/10.3390/buildings15020289 - 19 Jan 2025

Viewed by 636

Abstract

In this volatile, uncertain, complex, and ambiguous (VUCA) era, resilient and sustainable construction methods, such as prefabricated construction, are essential for addressing the planet’s sustainability challenges. However, disruptions in the prefabricated construction supply chain (PCSC) frequently arise, seriously impeding the performance of prefabricated [...] Read more.

In this volatile, uncertain, complex, and ambiguous (VUCA) era, resilient and sustainable construction methods, such as prefabricated construction, are essential for addressing the planet’s sustainability challenges. However, disruptions in the prefabricated construction supply chain (PCSC) frequently arise, seriously impeding the performance of prefabricated building projects. Therefore, this study aims to identify the factors influencing the prefabricated construction supply chain (RPCSC) and analyze their intrinsic interconnections. Initially, an exhaustive literature review was conducted to identify the primary factors affecting the RPCSC. Subsequently, the Delphi technique was applied to validate and refine the list of factors, resulting in the identification of 11 key concepts. Finally, the impact of these concepts on the RPCSC, along with their interactions, was assessed using the fuzzy cognitive map (FCM) approach. The results indicate that these factors can be ranked by their degree of effect on the RPCSC: information exchange/sharing, research and development, the performance of prefabricated components, decision alignment, the construction of prefabricated buildings, relationship quality among members, professional management personnel/labor quality, supply–demand consistency, cost/profit sharing, policies and regulations, and transport risk. Furthermore, this study elucidates both the individual and synergistic effects of these factors on the RPCSC by constructing a pathway map. Full article

(This article belongs to the Special Issue Promoting Green, Sustainable, and Resilient Urban Construction)

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36 pages, 15000 KiB

Open AccessArticle

Modeling Soil Behavior with Machine Learning: Static and Cyclic Properties of High Plasticity Clays Treated with Lime and Fly Ash

by Gebrail Bekdaş, Yaren Aydın, Sinan Melih Nigdeli, İnci Süt Ünver, Wook-Won Kim and Zong Woo Geem

Buildings 2025, 15(2), 288; https://doi.org/10.3390/buildings15020288 - 19 Jan 2025

Viewed by 734

Abstract

Soils may not always be suitable to fulfill their intended function. Soil improvement can be achieved by mechanical or chemical methods, especially in transportation facilities. L and FA additives are frequently used as chemical improvement additives. In this study, two natural clay samples [...] Read more.

Soils may not always be suitable to fulfill their intended function. Soil improvement can be achieved by mechanical or chemical methods, especially in transportation facilities. L and FA additives are frequently used as chemical improvement additives. In this study, two natural clay samples with extreme and very high plasticity were improved by using L and FA admixtures, and their properties under static and repeated loads were investigated by ML methods. Two soil samples from two different sites were analyzed. In this study, eight datasets were used. There are 14 inputs, including specific gravity (Gs), void ratio (eo), sieve analysis (+No.4, −No.200), clay size, LL, plastic limit (PL), plasticity index (PI), linear shrinkage (Ls), shrinkage limit (SL), cure day, agent, clay type, and agent percentage. The outputs are index and swelling properties (compressive, percent), compressive strengths, modulus of elasticity, and compressibility properties in soaked and non-soaked conditions. Prediction is attempted with different ML (ML) techniques. ML techniques used for regression (such as Decision Tree Regression (DTR) and K-nearest neighbors (KNN)). SHapley Additive Explanations (SHAP), the impact of inputs on outputs were observed, and it was generally found that PL and LL had the highest impact on outputs. Different performance metrics are used for evaluation. The results showed that these ML techniques can predict the static and cyclic properties of extremely high plasticity clays with high performance (R² > 0.99). These results highlight the general applicability of the used ML models on different datasets containing soil properties. Full article

(This article belongs to the Section Building Materials, and Repair & Renovation)

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15 pages, 5581 KiB

Open AccessArticle

Finite Element Analysis of the Excavation Stability of Deep and Large Ventilation Shafts of Zimuyan Tunnel Using the Raise Boring Machine Method in a Karst Area

by Guofeng Wang, Fayi Deng, Kaifu Ren, Yougqiao Fang and Haiyan Xu

Buildings 2025, 15(2), 287; https://doi.org/10.3390/buildings15020287 - 19 Jan 2025

Viewed by 637

Abstract

The excavation of deep and large vertical shafts in karst areas can easily lead to sudden changes in the stress field of the surrounding rock and even cause disasters such as cave collapses. To investigate the influence of karst areas on the stability [...] Read more.

The excavation of deep and large vertical shafts in karst areas can easily lead to sudden changes in the stress field of the surrounding rock and even cause disasters such as cave collapses. To investigate the influence of karst areas on the stability of deep and large vertical shaft excavation using the raise boring machine (RBM) method, based on the ventilation vertical shaft project of Zimuyan Tunnel, the influence of karst caves on the displacement and stress fields of the surrounding rock during the construction stage of the vertical shaft was analyzed using the finite element simulation method. Furthermore, the influence of the cave dimensions and the distance between the cave and the shaft on the stability of the surrounding rock was evaluated. The results indicate that the karst cave caused an increase in the radial displacement of the surrounding rock, and the radial displacements and stress in the surrounding rock increased linearly with depth. However, the radial displacement of the surrounding rock in the range of 20D to 21D (D is the well diameter) above the bottom of the well, and the radial stress of the surrounding rock in the range of 7D above and below the depth of the cave, are significantly affected by the cave. When the cavern size increased from 0 to 2.0D, the maximum radial displacement of the surrounding rock in each construction stage increased by 10.7, 16.6, 2.3, and 2.2 times, respectively. Moreover, when the distance between the cavern and the well was increased from 0.5D to 2.0D, the maximum radial displacements of the surrounding rock corresponding to each construction stage were reduced by 51.5%, 61.6%, 40.7%, and 18.4%, respectively. These findings can provide valuable references for the design, construction, and monitoring of deep and large vertical shafts in karst areas. Full article

(This article belongs to the Special Issue Research on the Construction Mechanical Behavior and Deformation Characteristics of Lining Structure—2nd Edition)

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17 pages, 5167 KiB

Open AccessArticle

Optimization of Cast-Steel Tubular Circular-Hollow-Section Connections Based on Depth-First Search Algorithm

by Kaien Jiang, Ziming Yang, Ju Chen, Guoer Lv and Huafeng Yu

Buildings 2025, 15(2), 286; https://doi.org/10.3390/buildings15020286 - 19 Jan 2025

Viewed by 683

Abstract

This study introduces a novel design for a cast-steel joint in the shape of a T, aimed at resolving concerns regarding stress concentration at points where geometric intersections occur and enhancing the quality of welding in T-shaped welded joints. The proposed integrated design [...] Read more.

This study introduces a novel design for a cast-steel joint in the shape of a T, aimed at resolving concerns regarding stress concentration at points where geometric intersections occur and enhancing the quality of welding in T-shaped welded joints. The proposed integrated design framework greatly facilitated the successful construction of a three-dimensional joint between a brace and a chord at a T-shaped node. The geometric parameters of curves in the connector were optimized using a depth-first search algorithm, resulting in control points for the optimized curve. Computer-aided design software was then employed to obtain the refined connector. The design framework has the ability to produce designs with smooth and uninterrupted boundaries, making them highly compatible with traditional casting methods and effectively tackling the manufacturing challenges related to topology optimization. The numerical simulation results demonstrate that, in comparison to traditionally welded T-joints of the same size, the stress concentration factor of the optimized joints exhibits a significant reduction, accompanied by a notable disparity in stress distribution. Moreover, the impact of the thickness of the brace and the axial compression ratio on the stress concentration factor of the optimized joints was relatively insignificant. The stress concentration factor of the cast-steel joint was reduced by more than 84%, leading to a significant enhancement in fatigue performance. Full article

(This article belongs to the Section Building Structures)

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19 pages, 5374 KiB

Open AccessArticle

Research on Flexural Performance of Basalt Fiber-Reinforced Steel–Expanded Polystyrene Foam Concrete Composite Wall Panels

by Fang Liu, Long Zhao, Longxin Yuan, Gang Wu, Ran Zheng and Yusong Mu

Buildings 2025, 15(2), 285; https://doi.org/10.3390/buildings15020285 - 19 Jan 2025

Viewed by 513

Abstract

This paper presents a novel design of prefabricated steel–EPS foam concrete composite wall panels, which can solve issues such as long curing times, decreased impermeability and durability, easy corrosion of steel reinforcement, and difficult construction under the cold climate conditions in Northeast China. [...] Read more.

This paper presents a novel design of prefabricated steel–EPS foam concrete composite wall panels, which can solve issues such as long curing times, decreased impermeability and durability, easy corrosion of steel reinforcement, and difficult construction under the cold climate conditions in Northeast China. A parametric analysis of the composite wallboard was carried out using the finite-element analysis software ABAQUS 6.12. In-depth exploration was conducted on the contributions of parameters such as the density of foam concrete, the strength of cold-formed thin-walled C-section steel, and the cross-sectional height of cold-formed thin-walled C-section steel compared to the overall flexural bearing capacity of the composite wallboard as well as the impacts of these parameters on the failure modes. The mechanical properties of the composite wallboard were verified through four-point bending tests. The bearing capacity of this composite wallboard can reach up to 100.58 kN at most, and its flexural bearing capacity can reach 30.44 kN·m. Meanwhile, its ductility coefficient of 2.9 is also within the optimal range. The research results confirm the superior mechanical properties of the designed composite wallboard, providing beneficial references for the research on similar composite material structures. Full article

(This article belongs to the Section Building Structures)

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28 pages, 16692 KiB

Open AccessArticle

Automatic Generation of Precast Concrete Component Fabrication Drawings Based on BIM and Multi-Agent Reinforcement Learning

by Chao Zhang, Xuhong Zhou, Chengran Xu, Zhou Wu, Jiepeng Liu and Hongtuo Qi

Buildings 2025, 15(2), 284; https://doi.org/10.3390/buildings15020284 - 19 Jan 2025

Viewed by 659

Abstract

Fabrication drawings are essential for design evaluation, lean manufacturing, and quality detection of precast concrete (PC) components. Due to the complicated shape of PC components, the fabrication drawing needs to be customized to determine manufacturing dimensions and relevant assembly connections. However, the traditional [...] Read more.

Fabrication drawings are essential for design evaluation, lean manufacturing, and quality detection of precast concrete (PC) components. Due to the complicated shape of PC components, the fabrication drawing needs to be customized to determine manufacturing dimensions and relevant assembly connections. However, the traditional manual drawing method is time-consuming, labor-intensive, and error-prone. This paper presents a BIM-based framework to automatically generate the readable drawing of PC components using building information modeling (BIM) and multi-agent reinforcement learning (MARL). Firstly, an automated generation method is developed to transform BIM model to view block. Secondly, a graph-based representation method is used to create the relationship between blocks, and a reward mechanism is established according to the drawing readability criterion. Subsequently, the block layout is modeled as a layout optimization problem, and the internal spacing and position of functional category blocks are regarded as agents. Finally, the agents collaborate and interact with the environment to find the optimal layout with the guidance of a reward mechanism. Two different algorithms are utilized to validate the efficiency of the proposed method (MADQN). The proposed framework is applied to PC stairs and a double-sided shear wall to demonstrate its practicability. Full article

(This article belongs to the Section Building Structures)

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28 pages, 6216 KiB

Open AccessArticle

Monitoring Environmental and Structural Parameters in Historical Masonry Buildings Using IoT LoRaWAN-Based Wireless Sensors

by Noëlla Dolińska, Gabriela Wojciechowska and Łukasz Bednarz

Buildings 2025, 15(2), 282; https://doi.org/10.3390/buildings15020282 - 19 Jan 2025

Viewed by 787

Abstract

This study investigates the impact of environmental conditions on the structural integrity and energy dynamics of historical masonry buildings using an IoT (Internet of Things) LoRaWAN-based (Long Range Wide Area Network) wireless sensor system. Over a six-month period, sensors were used to monitor [...] Read more.

This study investigates the impact of environmental conditions on the structural integrity and energy dynamics of historical masonry buildings using an IoT (Internet of Things) LoRaWAN-based (Long Range Wide Area Network) wireless sensor system. Over a six-month period, sensors were used to monitor wall temperature, wall humidity, air temperature, air humidity, crack width, and crack displacement. The data revealed significant correlations between environmental parameters and structural changes. Higher temperatures were associated with increased crack width, while elevated humidity levels correlated with greater crack displacement, showing the potential weakening of the masonry structure. Seasonal variations highlighted the cyclical nature of these changes, emphasizing the need for seasonal maintenance. Additionally, the findings suggest that managing temperature and humidity levels can optimize the building’s energy efficiency by reducing the need for additional heating or cooling. The use of LoRaWAN sensors provided real-time, remote monitoring capabilities, offering a cost-effective and scalable solution for preserving historical buildings. This study underscores the importance of continuous environmental and structural monitoring for the preservation of heritage sites. It also highlights the potential for integrating proactive maintenance strategies and energy optimization, ensuring long-term sustainability. By leveraging this IoT-based approach, this research contributes to the broader field of heritage conservation, offering a universal framework that can be applied to historical buildings worldwide, enhancing both their structural integrity and energy performance. Full article

(This article belongs to the Section Building Energy, Physics, Environment, and Systems)

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34 pages, 10269 KiB

Open AccessArticle

Numerical Study of the Effect of Out-of-Plane Distance in the Lateral Direction at the Mid-Span of a Steel Beam on the Sectional Moment Capacity

by Ahmed Mohamed Sayed, Nageh M. Ali, Mishal H. Aljarbou, Abdullah Alzlfawi, Salman Aldhobaib, Hani Alanazi and Abdulmalik H. Altuwayjiri

Buildings 2025, 15(2), 283; https://doi.org/10.3390/buildings15020283 - 18 Jan 2025

Viewed by 642

Abstract

Steel I-beams may be subject to deviation from their normal path towards the lateral direction due to obstacles along their axis line. This deviation in the lateral direction, i.e., the out-of-plane distance, affects the behavior of the steel beams and may reduce their [...] Read more.

Steel I-beams may be subject to deviation from their normal path towards the lateral direction due to obstacles along their axis line. This deviation in the lateral direction, i.e., the out-of-plane distance, affects the behavior of the steel beams and may reduce their ultimate capacity. To obtain this effect, finite element modeling (FEM) was used to model these beams with and without an out-of-plane distance at the mid-span beam length with several different variables. These variables were the out-of-plane distance, cross-section dimensions, beam length, and steel yield stress. The reliability of using FEM simulation was confirmed by comparing the experimental test results of 25 available steel beams in previous studies. The results indicate the high accuracy of the simulation of this beam in terms of ultimate capacity, structural behavior, and deformation patterns. After verifying the results, 116 broad-flange I-beam (BFIB) steel beams with different out-of-plane distances were modeled. The results showed that using an out-of-plane distance equal to the flange width of the BFIB-300 cross-section caused a 60% decrease in the ultimate capacity. The reduction ratios in the ultimate moment capacity in out-of-plane steel beams were directly proportional to the out-of-plane distance, cross-sectional dimensions, and steel yield stress, while the beam length had no effect. Failure in beams containing an out-of-plane distance occurs as a result of a global buckling in the upper flange, which contains tensile stresses at the outer edge and compressive stresses at the inner edge, with stress concentration occurring at the point of contact of the out-of-plane part with the main beam. The prediction results of the design codes were compared with the results of experimental tests and the FEM analysis of the beams with and without out-of-plane distances. For all the beams with out-of-plane distances, all the design codes were unable to predict this ultimate capacity. Full article

(This article belongs to the Special Issue Advanced Studies on Steel Structures)

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21 pages, 4914 KiB

Open AccessArticle

Physical Properties, Chemical Structure, and Microstructure of Thermoplastic Polyurethane Recycled Material-Modified Asphalt

by Peng Yang, Peiliang Cong, Hongjie Hao and Pengfei Xiong

Buildings 2025, 15(2), 281; https://doi.org/10.3390/buildings15020281 - 18 Jan 2025

Viewed by 640

Abstract

Firstly, thermoplastic polyurethane recycled material (TPRM) particles were used to prepare modified asphalt. Then, the modified asphalt’s physical properties were investigated. The results show that the TPRM particles improved its high-temperature performance, low-temperature crack resistance, and shear behavior due to its increased cohesion [...] Read more.

Firstly, thermoplastic polyurethane recycled material (TPRM) particles were used to prepare modified asphalt. Then, the modified asphalt’s physical properties were investigated. The results show that the TPRM particles improved its high-temperature performance, low-temperature crack resistance, and shear behavior due to its increased cohesion and low-temperature fracture energy levels. Thermal susceptibility was affected by the degree of swelling and dissolution of the TPRM particles, the composition of the asphalt, and the interface effect between the asphalt molecules and both the regular and slender–irregular TPRM particles. The TPRM particles swelled and dissolved after absorbing the light components of asphalt. Changes in the shearing temperature and time made the TPRM particles swell and dissolve more than changes in the activation temperature and time. An increase in the shearing/activation temperature and time increased the hydrogen bond content in the modified asphalt due to the rearrangement of the polyurethane’s molecular structure and the hydrogen bonds formed by the asphaltene and polyurethane molecules. Slender–irregular TPRM and “sea–island” and hilly and gulley structures were found in the modified asphalt matrix. Full article

(This article belongs to the Special Issue The Application of New Nano/Micron Bio-Originated Supplementary Materials in Construction)

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29 pages, 5032 KiB

Open AccessReview

Professional Barriers in Energy Efficiency Retrofits—A Solution Based on Information Flow Modeling

by Xilong Liao, Chun Wang, Baiyi Li, Baizhan Li and Chenqiu Du

Buildings 2025, 15(2), 280; https://doi.org/10.3390/buildings15020280 - 18 Jan 2025

Viewed by 712

Abstract

The challenge of high energy consumption and carbon emissions within China’s construction industry has become increasingly urgent, as over 40% of buildings are still non-energy efficient. The multifaceted nature of systems involved in building retrofits results in a complex project, with barriers in [...] Read more.

The challenge of high energy consumption and carbon emissions within China’s construction industry has become increasingly urgent, as over 40% of buildings are still non-energy efficient. The multifaceted nature of systems involved in building retrofits results in a complex project, with barriers in both retrofit design and construction becoming increasingly evident. This research comprehensively assesses the common barriers in building retrofits and investigates the potential for integrating energy-efficient retrofits with information flow modeling from an interdisciplinary perspective. In order to pinpoint the main barriers hindering building retrofits, this study employs the bibliometric software VOSviewer. The analysis uncovers that the primary obstacles to energy-saving renovations are categorized into technical, economic, environmental, and other barriers. These barriers are characterized by a high degree of specialization, the inadequate integration of information, and limited collaboration among stakeholders. Subsequently, a qualitative literature review was conducted following the PRISMA methodology, which screened 40 key sources. The following conclusions were drawn: (1) The design of energy-saving renovation processes is impeded by the limited professional perspectives within the construction industry, which restricts the practical applicability; (2) Decision making for energy-saving renovations encounters notable professional barriers and suffers from inadequate information integration; (3) There is a lack of clarity regarding information needs during the implementation phase, and no effective platform exists for information coordination; (4) Risk analyses in complex energy-saving renovations largely depend on expert interviews, lacking robust scientific tools. These findings highlight that knowledge gaps and information asymmetry are the central challenges. To tackle these issues, this paper suggests the implementation of an information flow model that integrates the IDEF0 and DSM for building energy-saving retrofit projects. The IDEF0 model can clearly describe the interaction relationship of all expert information through functional decomposition, while the DSM can show the dependency relationship and information flow path among specialties through the matrix structure. This model is anticipated to enhance professional information integration and collaboration. It is proposed that improved information integration and collaboration under this framework will significantly promote the advancement of professional generative AI. Full article

(This article belongs to the Section Building Energy, Physics, Environment, and Systems)

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16 pages, 2215 KiB

Open AccessArticle

Advanced Damage Monitoring in Beam Structures Using Grey Wolf Optimizer and Additional Masses

by Abdallah Salama, Alaa El-Sisi, Atef Eraky and Shimaa Emad

Buildings 2025, 15(2), 279; https://doi.org/10.3390/buildings15020279 - 18 Jan 2025

Viewed by 556

Abstract

Dynamic characteristics are of significant interest to researchers in the field of damage detection. Among these, natural frequencies stand out due to their high accuracy and resistance to noise. However, relying solely on natural frequencies is often insufficient for determining the depth and [...] Read more.

Dynamic characteristics are of significant interest to researchers in the field of damage detection. Among these, natural frequencies stand out due to their high accuracy and resistance to noise. However, relying solely on natural frequencies is often insufficient for determining the depth and location of damage. To address this limitation, additional masses can be strategically placed at different locations on structural elements, altering the natural frequencies. Each mass placement creates a distinct dynamic scenario with a unique frequency profile, enabling a more comprehensive analysis. In this study, additional masses were introduced at specific elements of the beam structure within the numerical model which were then strategically placed at various locations along the beam. The resulting shifts in natural frequencies served as inputs to the Grey Wolf Optimizer (GWO), which identified elements with stiffness reductions indicative of damage. A custom MATLAB code was developed to perform finite element analysis on the numerical model. The results were validated against previously published experimental data, demonstrating the method’s reliability with a 5% difference. A parametric study involving both simple and continuous span beams was performed. The procedure effectively detected damage severities of 10%, 25%, and 50%, with corresponding errors of 4.3%, 0.44%, and 0.02%, respectively. Full article

(This article belongs to the Special Issue Recent Developments in Structural Health Monitoring)

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17 pages, 5853 KiB

Open AccessArticle

A Study of Composite Salt Erosion Resistance of Nano-Modified Cement Mortar in Early Ages

by Jia Guo, Tao Zheng, Fei Mou, Yang Qin, Zhi Wang, Shiyi Zhang and Hui Li

Buildings 2025, 15(2), 278; https://doi.org/10.3390/buildings15020278 - 18 Jan 2025

Viewed by 710

Abstract

Corrosion of traditional cement mortar is a critical issue in karst areas. Composite salt, i.e., sulfate–chloride salt, represents a typical corrosion agent due to the abundance of Cl⁻ and SO₄²⁻ ions in such geological environments. In this study, we used [...] Read more.

Corrosion of traditional cement mortar is a critical issue in karst areas. Composite salt, i.e., sulfate–chloride salt, represents a typical corrosion agent due to the abundance of Cl⁻ and SO₄²⁻ ions in such geological environments. In this study, we used nano-metakaolin to enhance the physical and mechanical properties of cement mortar in the early aging stages, simulating groundwater corrosion by a compound salt solution in the karst region. The appearance and the change in the flexural/compressive strength of cement mortar upon the nano-metakaolin addition in the early aging stages under dry and wet cycling conditions were analyzed and combined with the results of scanning electron microscopy, thermogravimetric analysis, and other methods, revealing the underpinning mechanism behind the function changes of nano-metakaolin-modified cement mortar. The results show that nano-metakaolin effectively promotes cement hydration in the early aging stages. The flexural/compressive strength after 7 days of aging with 1% of added nano-metakaolin increased by 10.38% and 4.41%, respectively, compared to ordinary cement mortar. Furthermore, adding 1–5% of nano-metakaolin under dry and wet cycling and the coupling effect of chloride and sulfate erosion effectively reduce the damage of harmful ions on the cement mortar, leading to evident corrosion inhibition. The generation of hydration products increased after adding the Ghanaian metakaolin, filling the microcracks and micropores, and increasing the overall microstructural compactness. Full article

(This article belongs to the Special Issue Advances in Civil Engineering Materials: Design, Characterization, Corrosion and Durability)

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24 pages, 34306 KiB

Open AccessArticle

Satisfaction with Nighttime Outdoor Activity Environment Among Elderly Residents in Old Gated Communities

by Fang Wen, Liang Peng, Bo Zhang, Yan Zhang and Yuyang Zhang

Buildings 2025, 15(2), 277; https://doi.org/10.3390/buildings15020277 - 18 Jan 2025

Viewed by 548

Abstract

China, like many other countries around the world, faces a rapidly aging population. “Aging in place” is the most popular choice for older people in China, with more than 90% of urban older people living in the same residential areas they did in [...] Read more.

China, like many other countries around the world, faces a rapidly aging population. “Aging in place” is the most popular choice for older people in China, with more than 90% of urban older people living in the same residential areas they did in middle age. Nighttime outdoor activity (NOA) is popular among the elderly and has a positive impact on both their physical and mental health. However, the conditions of nighttime activity places in old gated communities often do not meet the activity needs of the elderly, and there are problems such as low lighting and poor accessibility. This study focuses on typical old gated communities in a large city and analyzes data on three dimensions of independent variables: the lighting of activity places, the built environment of old gated communities, and the attributes of the elderly residents themselves. Taking “satisfaction with the environment for NOAs”, “the biggest environmental problem with NOAs”, and “locations that need improved lighting” as dependent variables, we used machine learning to calculate the contributions of various influencing factors on the dependent variables. It was found that the most important factors that influence satisfaction with the NOA environments are lighting levels, with the built environment or elderly residents’ attributes being less important. The most important factor that influences older people’s judgment of “locations that need improved lighting” is the perception of safety related to lighting in NOAs, followed by the perception of uniform lighting and green areas in their gated community. This study provides a reference for the renovation of age-friendly community environments as well as the overall enhancement of the nighttime activity environments in old gated communities. Full article

(This article belongs to the Section Architectural Design, Urban Science, and Real Estate)

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30 pages, 6888 KiB

Open AccessArticle

Continuity Amid Commercial Buildings in Yeonnam-dong, Seoul

by Jae-Young Lee

Buildings 2025, 15(2), 276; https://doi.org/10.3390/buildings15020276 - 18 Jan 2025

Viewed by 278

Abstract

This study tracks changes in commercial buildings in Yeonnam-dong that have undergone commercial transformation, examining these shifts within the context of urban organization and their relationships with economic and socio-cultural flows. It also analyzes the architectural elements that reflect the placeness characteristics of [...] Read more.

This study tracks changes in commercial buildings in Yeonnam-dong that have undergone commercial transformation, examining these shifts within the context of urban organization and their relationships with economic and socio-cultural flows. It also analyzes the architectural elements that reflect the placeness characteristics of an area. On-site surveys were conducted to assess the continuity and discontinuity in the characteristics of 62 renovated and 40 newly constructed buildings. Additionally, shifts in social perceptions regarding physical changes were explored through an analysis of commercial districts and interviews with visitors, store owners, and architects. Yeonnam-dong has a distinct physical environment, as well as economic, social, and cultural characteristics that distinguish it from mainstream areas, such as large apartment complexes and typical commercial zones. The area, with its winding alleyways from the pre-modern period and low-rise housing—marginalized from large-scale development—evoked nostalgia and created a distinctive sense of authenticity or placeness, which was further enhanced by the presence of exotic restaurants, cafés, ateliers, and creative activities of early gentrifiers. However, rapid commercialization has led to the displacement of these early gentrifiers, an influx of new investments and construction, and shifts in commercial flows. Consequently, the area’s authenticity has become diluted, and visitors’ perceptions of it have changed. Despite this, architectural elements observed in renovated buildings are preserved and incorporated into newly constructed ones. Features such as semi-basements, exterior straight stairs, and brick façades continue to reflect the locality. Detached and multi-household homes from the 1960s to the 1990s have evolved into a new hybrid commercial–residential form designed for commercial purposes. This is a response to small plot sizes in Korean residential areas and reflects the current economic and cultural demands of commercial gentrification. The urban and architectural characteristics of this area are not only a unique physical environment but also hold socio-cultural significance as ordinary heritage. Therefore, this study proposes institutional measures to preserve urban and architectural continuity while controlling the ongoing commercialization. Full article

(This article belongs to the Section Architectural Design, Urban Science, and Real Estate)

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16 pages, 3862 KiB

Open AccessArticle

A Navier–Stokes-Informed Neural Network for Simulating the Flow Behavior of Flowable Cement Paste in 3D Concrete Printing

by Tianjie Zhang, Donglei Wang and Yang Lu

Buildings 2025, 15(2), 275; https://doi.org/10.3390/buildings15020275 - 18 Jan 2025

Viewed by 465

Abstract

In this work, we propose a Navier–Stokes-Informed Neural Network (NSINN) as a surrogate approach to predict the localized flow behavior of cementitious materials for advancing 3D additive construction technology to gain fundamental insights into multiscale mechanisms of cement paste rheology. NS equations are [...] Read more.

In this work, we propose a Navier–Stokes-Informed Neural Network (NSINN) as a surrogate approach to predict the localized flow behavior of cementitious materials for advancing 3D additive construction technology to gain fundamental insights into multiscale mechanisms of cement paste rheology. NS equations are embedded into the NSINN to interpret the flow pattern in the 3D printing barrel. The results show that the presented NSINN has a higher accuracy compared to a traditional artificial neural network (ANN) as the Mean Square Errors (MSEs) of the u, v, and p predicted by NSINN are

1.25 \times 10^{- 4}

,

1.85 \times 10^{- 5}

, and

3.91 \times 10^{- 3}

, respectively. Compared to the ANN, the MSE of the predictions are

5.88 \times 10^{- 2}

,

4.17 \times 10^{- 3}

, and

1.72 \times 10^{- 2}

, respectively. Moreover, the mean prediction time used in the NSINN, the ANN, and Computational Fluid Dynamics (CFD) are 0.039 s, 0.014 s, and 3.37 s, respectively. That means the method is more computationally efficient at performing simulations compared to CFD which is mesh-based. The NSINN is also utilized in studying the relationship between geometry and extrudability. The ratio (R = 0.25, 0.5, and 0.75) between the diameter of the outlet and that of the domain is studied. It shows that a larger ratio (R = 0.75) can lead to better extrudability of the 3D concrete printing (3DCP). Full article

(This article belongs to the Special Issue Advances in Cementitious Materials)

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14 pages, 4777 KiB

Open AccessArticle

Experimental Investigation on Toughness of SFRC and Bond Behavior with Reinforcing Bars

by Hongmei Zhang, Zizhao Tang, Jinguang Li, Zheming Hu and Qian Feng

Buildings 2025, 15(2), 274; https://doi.org/10.3390/buildings15020274 - 18 Jan 2025

Viewed by 439

Abstract

Steel-fiber reinforced concrete (SFRC) has the advantages of high strength, durability, and crack prevention ability. Studies on the compressive strength, tensile strength and flexural behavior of SFRC have been carried out by many researchers. In this paper, the toughness of SFRC along with [...] Read more.

Steel-fiber reinforced concrete (SFRC) has the advantages of high strength, durability, and crack prevention ability. Studies on the compressive strength, tensile strength and flexural behavior of SFRC have been carried out by many researchers. In this paper, the toughness of SFRC along with the bond behavior between SFRC and reinforcement were investigated. Hooked-end and straight steel fibers were chosen in the toughness tests of SFRC. The test results show that the SFRC mixtures with hooked-end steel fibers exhibit higher toughness. In addition, hooked-end steel fibers were chosen to be mixed in the SFRC to demonstrate the bond behavior between SFRC and reinforcing bars. Different embedment lengths were considered in the tests to show the influence of the anchorage area on the bond–slip responses in the pull-out tests. The failure modes for different specimens were exhibited. The results show that the embedment length more than 5 times the bar diameter causes tensile failure of the reinforcement, while the embedment length of 3 times the bar diameter causes pull-out failure of the reinforcement. Full article

(This article belongs to the Special Issue Mechanical Properties of Advanced Metal Structures in Civil Infrastructure)

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15 pages, 1393 KiB

Open AccessArticle

Turning Agricultural Biomass Ash into a Valuable Resource in the Construction Industry—Exploring the Potential of Industrial Symbiosis

by Olivera Bedov, Ana Andabaka and Suzana Draganić

Buildings 2025, 15(2), 273; https://doi.org/10.3390/buildings15020273 - 18 Jan 2025

Viewed by 527

Abstract

This paper presents a circular business model (CBM) designed to promote the valorization of agricultural biomass ash for producing an alternative binder in construction, aiming to reduce CO₂ emissions and landfill waste. The circular economy framework emphasizes regeneration and restoration to minimize resource [...] Read more.

This paper presents a circular business model (CBM) designed to promote the valorization of agricultural biomass ash for producing an alternative binder in construction, aiming to reduce CO₂ emissions and landfill waste. The circular economy framework emphasizes regeneration and restoration to minimize resource and energy use, waste generation, pollution, and other environmental impacts. Aligned with these principles of sustainability, the construction industry, energy sector and food processing industry can establish a shared interest through industrial symbiosis. In the proposed CBM, waste from one industry becomes an input for another. The model leverages industrial symbiosis by using sunflower husk ash (SHA) as an alternative hydroxide activator for alkali-activated materials. A case study of companies in the Republic of Serbia that produce SHA as waste forms the basis for this model, featuring promising results of experimental testing of three alkali-activated mortars produced by activating ground-granulated blast furnace slag (GGBFS) with different SHA contents (15, 25 and 35 wt% GGBFS), instead of commercially available hydroxide activators. The potential of SHA as an alternative activator was assessed by testing flow diameter and compressive strength at 7 and 28 days of curing. The highest 28-day compressive strength was attained for the addition of 25% SHA (28.44 MPa). The promising results provided a valid basis for CBM development. The proposed CBM is stream-based, resulting from merging and upgrading two existing industrial symbioses. This study highlights the benefits of the CBM while addressing the challenges and barriers to its implementation, offering insights into the possible integration of agricultural biomass ash into sustainable construction practices. Full article

(This article belongs to the Special Issue Advances in the Implementation of Circular Economy in Buildings)

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19 pages, 3415 KiB

Open AccessArticle

Recycling Waste Soils for Stability Enhancement in Bored Pile Construction

by Feng Li, Lei Zhang, Zhengzhen Wang, Qiqi Liu, Tiantao Su and Jinke Wang

Buildings 2025, 15(2), 272; https://doi.org/10.3390/buildings15020272 - 18 Jan 2025

Viewed by 379

Abstract

Instability in the hole wall of bored pile may cause serious environmental problems. Therefore, using the small hole expansion theory and elastic–plastic theory, we studied the instability mechanism of the hole wall of bored pile, determined the stress expansion solution of the soil [...] Read more.

Instability in the hole wall of bored pile may cause serious environmental problems. Therefore, using the small hole expansion theory and elastic–plastic theory, we studied the instability mechanism of the hole wall of bored pile, determined the stress expansion solution of the soil layer after the excavation of pile holes in the semi-infinite elastic soil layer, and established a mechanical model. Then, the stability of the hole wall of bored pile in the cohesive soil layer and sandy soil layer was analyzed, and a formula for calculating pile hole wall stability was obtained. Finally, the stability of the hole wall of bored pile under the action of mud slurry was calculated, and the stress on the pile hole wall was analyzed when local instability and overall instability occurred, respectively. The results show that in a sandy soil layer, the safety factor of the hole wall of bored pile has no connection with the depth of the pile hole but is related to the density of mud slurry in the pile hole. In unstable soil layers, the pile hole wall was prone to instability, and the stability of the hole wall could be improved by appropriately increasing the gravity of mud slurry. With the increase in pile diameter, the lateral displacement and deformation of the hole wall increase, and the displacement of the soil layer increases when the hole wall is unstable, increasing the possibility of forming variable cross-section piles correspondingly. Full article

(This article belongs to the Special Issue Recycling of Waste in Material Science and Building Engineering)

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