Buildings

24 pages, 10606 KB

Open AccessArticle

Response and Reinforcement Mechanisms of Fiber-Reinforced Concrete Subjected to Dynamic Splitting Tensile Loading After High-Temperatures Exposure

by Jing Dong, Guiming Chen, Xiaojie Chen, Juan Du and Shuai Yang

Buildings 2025, 15(24), 4416; https://doi.org/10.3390/buildings15244416 (registering DOI) - 6 Dec 2025

Abstract

Coupled high temperature and dynamic loading often leads to the complicated degradation of performance in industrial kilns, enclosures, or other concrete structures, which constitutes a serious hazard to the safety of concrete structure. To bridge this research gap, this study investigates not only [...] Read more.

Coupled high temperature and dynamic loading often leads to the complicated degradation of performance in industrial kilns, enclosures, or other concrete structures, which constitutes a serious hazard to the safety of concrete structure. To bridge this research gap, this study investigates not only the mechanical response but also the damage mechanisms of normal concrete (NC), basalt fiber-reinforced concrete (BFRC), and steel fiber-reinforced concrete (SFRC) under the coupled effects of high temperature and dynamic loading. Test specimens were conditioned for ambient conditions, 200 °C, 400 °C, and 600 °C, and underwent quasi-static and dynamic splitting tensile tests using the Split Hopkinson Pressure Bar (SHPB) with strain rates varying between 24 and 91 s⁻¹. Significantly, the high-temperature-induced degradation of all types of concrete is remarkably suppressed by fibers, especially steel fibers. The best thermal degradability resistance was displayed by the SFRC with the highest remaining residual dynamic strength, peak strain, and energy dissipation, especially in the most severe (600 °C, 0.15 MPa) circumstances among these three types of materials. All materials revealed a clear strain rate strengthening effect. An empirical model, integrating the coupling effect of strain rate, temperature, and fiber type in DIF, was also developed, yielding better prediction capability than those already available. This reveals that the comprehensive performance of SFRC can meet structure requests, so it is suitable for applications involving steel fiber in environments characterized by high temperature and high strain rates. Full article

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

31 pages, 4117 KB

Open AccessArticle

Time-Based Fire Resistance Performance of Axially Loaded, Circular, Long CFST Columns: Developing Analytical Design Models Using ANN and GEP Techniques

by Ç. Özge Özelmacı Durmaz, Süleyman İpek, Dia Eddin Nassani and Esra Mete Güneyisi

Buildings 2025, 15(24), 4415; https://doi.org/10.3390/buildings15244415 (registering DOI) - 6 Dec 2025

Abstract

Concrete-filled steel tube (CFST) columns are composite structural elements preferred in various engineering structures due to their superior properties compared to those of traditional structural elements. However, fire resistance analyses are complex due to CFST columns consisting of two components with different thermal [...] Read more.

Concrete-filled steel tube (CFST) columns are composite structural elements preferred in various engineering structures due to their superior properties compared to those of traditional structural elements. However, fire resistance analyses are complex due to CFST columns consisting of two components with different thermal and mechanical properties. Significant challenges arise because current design codes and guidelines do not provide clear guidance for determining the time-dependent fire performance of these composite elements. This study aimed to address the existing design gap by investigating the fire behavior of circular long CFST columns under axial compressive load and developing robust, accurate, and reliable design models to predict their fire performance. To this end, an up-to-date database consisting of 62 data-points obtained from experimental studies involving variable material properties, dimensions, and load ratios was created. Analytical design models were meticulously developed using two advanced soft computing techniques: artificial neural networks (ANNs) and genetic expression programming (GEP). The model inputs were determined as six main independent parameters: steel tube diameter (D), wall thickness (t_s), concrete compressive strength (f_c), steel yield strength (f_sy), the slenderness ratio (L/D), and the load ratio (μ). The performance of the developed models was comprehensively compared with experimental data and existing design models. While existing design formulas could not predict time-based fire performance, the developed models demonstrated superior prediction accuracy. The GEP-based model performed well with an R-squared value of 0.937, while the ANN-based model achieved the highest prediction performance with an R-squared value of 0.972. Furthermore, the ANN model demonstrated its excellent prediction capability with a minimal mean absolute percentage error (MAPE = 4.41). Based on the nRMSE classification, the GEP-based model proved to be in the good performance category with an nRMSE value of 0.15, whereas the ANN model was in the excellent performance category with a value of 0.10. Fitness function (f) and performance index (PI) values were used to assess the models’ accuracy; the ANN (f = 1.13; PI = 0.05) and GEP (f = 1.19; PI = 0.08) models demonstrated statistical reliability by offering values appropriate for the expected targets (f ≈ 1; PI ≈ 0). Consequently, it was concluded that these statistically convincing and reliable design models can be used to consistently and accurately predict the time-dependent fire resistance of axially loaded, circular, long CFST columns when adequate design formulas are not available in existing codes. Full article

(This article belongs to the Special Issue Advances in Composite Construction in Civil Engineering—2nd Edition)

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38 pages, 2910 KB

Open AccessArticle

Interpretation of the Pile Static Load Test Using Artificial Neural Networks

by Artur Sławomir Góral and Marek Lefik

Buildings 2025, 15(24), 4414; https://doi.org/10.3390/buildings15244414 (registering DOI) - 6 Dec 2025

Abstract

This study presents a novel approach for interpreting static load tests (SLT) of piles using Artificial Neural Networks (ANNs) integrated with the Meyer and Kowalow load-settlement mathematical model. Reliable estimation of pile bearing capacity and settlement behavior is critical for safe and economical [...] Read more.

This study presents a novel approach for interpreting static load tests (SLT) of piles using Artificial Neural Networks (ANNs) integrated with the Meyer and Kowalow load-settlement mathematical model. Reliable estimation of pile bearing capacity and settlement behavior is critical for safe and economical geotechnical design, particularly given the nonlinear and heterogeneous nature of soils. Traditional SLT interpretation methods, such as Chin-Kondner, Decourt, and hyperbolic fitting approaches, provide useful extrapolation of the ultimate capacity but are sensitive to test termination levels and parameter estimation uncertainties. The Meyer and Kowalow function offers a robust mathematical representation of the load-settlement curve, allowing decomposition of the total pile resistance into the shaft and base components. In this work, ANN models were trained to solve both the direct and inverse forms of the Meyer and Kowalow problem, enabling rapid identification of constitutive parameters (initial stiffness, nonlinearity coefficient, and ultimate capacity) from measured SLT data. Numerical experiments demonstrated that networks with a single hidden layer achieved accurate predictions with low RMSE for both training and test sets. The proposed ANN-based framework facilitates improved parameter identification, supports partial-load SLT interpretation, and provides a practical tool for engineers seeking the reliable prediction of pile performance under service loads. Full article

(This article belongs to the Section Building Structures)

36 pages, 26387 KB

Open AccessArticle

Evaluation of Residents’ Satisfaction with Cultural Spaces in Historic Districts Based on ERG Theory—A Case Study of Longweiguan Historic and Cultural District in Dali City, China

by Zitong Tang, Dingqing Zhang, Lu Zhang, Yingtao Qi and Mengying Wang

Buildings 2025, 15(24), 4413; https://doi.org/10.3390/buildings15244413 (registering DOI) - 6 Dec 2025

Abstract

Amid urbanization, historic districts serve as key carriers of urban cultural memory, confronting dual challenges of integrating tradition with modernity and balancing cultural inheritance with spatial renewal. Enhancing residents’ satisfaction with cultural spaces is crucial for improving their quality of life and promoting [...] Read more.

Amid urbanization, historic districts serve as key carriers of urban cultural memory, confronting dual challenges of integrating tradition with modernity and balancing cultural inheritance with spatial renewal. Enhancing residents’ satisfaction with cultural spaces is crucial for improving their quality of life and promoting the sustainable development of urban culture. However, existing research lacks systematic analysis of the intrinsic relationship between residents’ needs and spatial satisfaction, focusing on holistic conservation or spatial design. Using ERG Theory and taking Longweiguan Historic and Cultural District in Dali, China, as the case, this study explores how residents’ needs and cultural space satisfaction interact via theoretical construction and empirical analysis. It establishes a 20-index satisfaction evaluation system, adopting field surveys, in-depth interviews and Structural Equation Modeling (SEM) for quantitative analysis. Findings: (1) Residents reported moderate-to-high overall satisfaction with cultural spaces, where relatedness needs demonstrated the most significant impact on satisfaction, while growth needs scored lowest. (2) Existence needs directly affect satisfaction through basic elements like spatial safety and indirectly strengthen relatedness needs. (3) Cultural industry spaces hinder satisfaction due to disconnected innovation and resident participation. Thus, a “safety–social interaction–innovation” strategy is proposed to support the living conservation and sustainable development of historic districts. Full article

(This article belongs to the Special Issue Renewal Design and Challenge of Urban and Rural Livable Environments in the Age of Population Shrinkage)

22 pages, 4764 KB

Open AccessArticle

Study on the Influence Mechanism of Metro-Induced Vibrations on Adjacent Tunnels and Vibration Isolation Measures

by Qige Ye, Bin Zhang, Xingjia Tang, Yixuan Zheng and Jie Yuan

Buildings 2025, 15(24), 4412; https://doi.org/10.3390/buildings15244412 (registering DOI) - 6 Dec 2025

Abstract

To investigate the effectiveness of vibration mitigation and isolation measures for adjacent tunnels in a metro-induced vibration environment, this study employed a similarity theory-based scaled model test at a ratio of 1:15. The prototype was the Guangzhou 500 kV Suixi-Chuting power transmission tunnel [...] Read more.

To investigate the effectiveness of vibration mitigation and isolation measures for adjacent tunnels in a metro-induced vibration environment, this study employed a similarity theory-based scaled model test at a ratio of 1:15. The prototype was the Guangzhou 500 kV Suixi-Chuting power transmission tunnel project. The experimental methodology was designed to simulate the vibration impact on adjacent tunnels from metro loading and to evaluate the performance of various countermeasures. The vibration response mechanisms induced by different mitigation materials were analyzed. The results demonstrate the theoretical feasibility of the overall design of the scaled model test, which accurately reproduces the vibration influence on adjacent tunnels from metro loads. Both Expanded Polystyrene (EPS) and rubber particles were found to provide measurable vibration reduction. However, the attenuation achieved by EPS was significantly greater than that of rubber particles, indicating the superior performance of EPS as a vibration isolation material. Furthermore, the isolation mechanisms of both materials were discussed based on observations of their behavioral changes during the vibration isolation process. The findings of this study offer valuable insights and a reference for selecting appropriate vibration mitigation materials in practical engineering applications. Full article

(This article belongs to the Special Issue Advances in Building Foundation Engineering and Underground Structures)

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24 pages, 5142 KB

Open AccessArticle

A Method for Extracting Indoor Structural Landmarks Based on Indoor Fire Protection Plan Images of Buildings

by Yueyong Pang, Heng Xu, Lizhi Miao and Jieying Zheng

Buildings 2025, 15(24), 4411; https://doi.org/10.3390/buildings15244411 (registering DOI) - 6 Dec 2025

Abstract

Indoor landmarks play a crucial role in the process of indoor positioning and route planning for pedestrians or unmanned devices. Indoor structural landmarks, a type of indoor landmarks, can provide rich steering and semantic descriptions for indoor navigation services. However, most traditional indoor [...] Read more.

Indoor landmarks play a crucial role in the process of indoor positioning and route planning for pedestrians or unmanned devices. Indoor structural landmarks, a type of indoor landmarks, can provide rich steering and semantic descriptions for indoor navigation services. However, most traditional indoor landmark extraction methods rely on indoor points of interest and indoor vector map data. These methods face the problem of difficult acquisition of indoor data and overlook the exploration of indoor structural landmarks. Therefore, this paper innovatively proposes a method for extracting indoor structural landmarks based on the commonly available indoor fire protection plan images. First, the HSV model is employed to eliminate noise from the original image, and vector data of indoor components is obtained using the constructed Canny operator. Subsequently, the visibility is calculated based on the grids of indoor space segmentation. Finally, the identification and extraction of indoor structural landmarks are achieved through grid visibility classification, directional clustering analysis, and spatial proximity verification. This approach opens up new ideas for indoor landmark extraction methods. The experimental results show that the method proposed in this paper can effectively extract indoor structural landmarks, the extraction accuracy of indoor structural landmarks reaches over 90%, verifying the feasibility of using indoor fire protection plan data for landmark extraction and expanding the data sources for indoor landmark extraction. Full article

(This article belongs to the Section Building Structures)

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16 pages, 1591 KB

Open AccessArticle

Research on Optimal Down-Sampling Method of Segmental Beam Edge Based on Double Regions

by Jiayan Yang, Zhihao Hu, Menghui Li, Xingli Jia and Junheng Guo

Buildings 2025, 15(24), 4410; https://doi.org/10.3390/buildings15244410 - 5 Dec 2025

Abstract

With the development of three-dimensional laser scanning technology, a large number of point cloud data generated has caused great computational pressure on storage, processing, and visualization. To this end, this paper proposes an edge-optimized voxel grid down-sampling method based on two regions, which [...] Read more.

With the development of three-dimensional laser scanning technology, a large number of point cloud data generated has caused great computational pressure on storage, processing, and visualization. To this end, this paper proposes an edge-optimized voxel grid down-sampling method based on two regions, which aims to reduce the amount of data while preserving key geometric accuracy and details. By defining the two regions of point cloud data, this method proposes a two-region point cloud down-sampling model according to the different point cloud deviation characteristics of the two regions, so as to simplify the point cloud data volume and accurately identify and retain the edge contour feature points. The experimental results show that the proposed method performs well under both low-precision and high-precision conditions. It can maintain the geometric features and surface area of the point cloud while simplifying the point cloud. Compared with other methods, it has outstanding performance in the top surface contour deviation index and surface area change rate. It has a high accuracy retention ability and good simplification effect and is suitable for a variety of application scenarios. Full article

(This article belongs to the Section Construction Management, and Computers & Digitization)

16 pages, 887 KB

Open AccessArticle

A Comparative Study of Waste Red-Clay Brick Powder (WRCBP) and Fly Ash (FA) as Precursors for Geopolymer Production

by Yifang He, Wei Tang, Chunran Wu, Baojun Zhao and Shicong Kou

Buildings 2025, 15(24), 4409; https://doi.org/10.3390/buildings15244409 - 5 Dec 2025

Abstract

Utilizing waste red-clay brick powder (WRCBP) as a precursor for manufacturing geopolymers is increasingly popular due to its environmental and economic benefits. However, the geopolymerization of this waste remains insufficiently explored. This study evaluates the differences in physical–mechanical properties and microstructural evolution of [...] Read more.

Utilizing waste red-clay brick powder (WRCBP) as a precursor for manufacturing geopolymers is increasingly popular due to its environmental and economic benefits. However, the geopolymerization of this waste remains insufficiently explored. This study evaluates the differences in physical–mechanical properties and microstructural evolution of WRCBP- and fly ash (FA)-based geopolymers to determine the reactivity of WRCBP. Mineral admixtures, including granulated blast furnace slag (GF) and metakaolin (MT), were incorporated with WRCBP to fabricate geopolymer pastes, while FA was used in parallel for comparison. The effects of activator modulus (1.2 and 1.4 for Na₂SiO₃) and curing conditions (65 °C and 90 °C) on the mechanical and microstructural performance of the prepared pastes were investigated through water demand analysis, compressive strength testing, mercury intrusion porosimetry (MIP), and scanning electron microscopy (SEM). The results indicate that WRCBP-based pastes achieved a comparable compressive strength (39.8 MPa) under appropriate alkali-activated and curing conditions relative to FA-based pastes (42.5 MPa). The modulus of the alkaline activator exerted a greater influence on strength development than the raw material composition. For both WRCBP- and FA-based pastes, 65 °C was identified as a more suitable curing temperature. Moreover, compared with FA-based pastes, pastes produced using WRCBP provide enhanced social and economic benefits. Overall, this study confirms that high-performance binders can be engineered by incorporating WRCBP, thereby supporting the development of sustainable low-carbon construction materials. Full article

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

25 pages, 4103 KB

Open AccessArticle

Studying the Jin Dynasty’s Border Defensive Tactics From a “History-Space” Standpoint-Taking the Settlements of Northwest Road and Southwest Road as an Example

by Dan Xie and Yanbo Wang

Buildings 2025, 15(24), 4408; https://doi.org/10.3390/buildings15244408 - 5 Dec 2025

Abstract

Settlements are the fundamental structural components of the Northwest and Southwest Routes, which were important defensive sectors of the Jin Dynasty’s Great Wall defense system. Under the Jurchen rule, these villages function as special conduits for investigating border defense tactics. However, historical document [...] Read more.

Settlements are the fundamental structural components of the Northwest and Southwest Routes, which were important defensive sectors of the Jin Dynasty’s Great Wall defense system. Under the Jurchen rule, these villages function as special conduits for investigating border defense tactics. However, historical document analysis is the main method used in present study on the Northwest and Southwest Roads, and comprehensive quantitative empirical data about the geographical organization of settlements are absent. As a result, research on the unique defense tactics of the Jin Dynasty is still not fully understood. This study establishes a dual “historical-spatial” analytical paradigm by examining settlement remnants from the Northwest and Southwest Roads in modern-day Inner Mongolia. In order to thoroughly examine defensive tactics within their distinct historical and geographical settings, it clarifies the building procedures, spatial distribution, and site selection features of these settlements using a combination of qualitative and quantitative methodologies. The results show: (1) The Southwest Road defense zone was continuously reinforced, whereas the Northwest Road defense zone steadily shrank inward from the standpoint of settlement construction. This illustrates how the Jin Dynasty’s macro-level defensive strategy changed from “military deterrence” to “tactical defense”. (2) In terms of military administration systems, ethnic composition differences and settlement defense functions were the main factors influencing the settlement patterns formed in the Northwest and Southwest Roads. (3) In terms of spatial distribution and site selection features, the Zhaotaosi settlements functioned as the core settlements integrating “command-troop garrison-combat operations,” in contrast to the conventional method of using the highest-level settlement as the rear command center. Full article

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

28 pages, 7778 KB

Open AccessArticle

Investigation of Strength of Polymer-Modified Fiber-Reinforced Concrete Under Water Saturation

by Yerlan Atenov, Isabai Bekbasarov and Nurzhan Shanshabayev

Buildings 2025, 15(24), 4407; https://doi.org/10.3390/buildings15244407 - 5 Dec 2025

Abstract

Ensuring the sufficient strength of concrete structures and buildings exposed to constant humidity is of great importance in hydraulic engineering, as increased humidity reduces the strength of concrete and ultimately destroys it. Although the static strength of concrete has been thoroughly studied, its [...] Read more.

Ensuring the sufficient strength of concrete structures and buildings exposed to constant humidity is of great importance in hydraulic engineering, as increased humidity reduces the strength of concrete and ultimately destroys it. Although the static strength of concrete has been thoroughly studied, its impact strength, including that in a wet state, remains unexplored. This is especially relevant for modified concretes, for which there are no experimental data on the effect of moisture on their strength characteristics. This article presents the results of an experimental quantitative assessment of the static and impact strength of polymer–cement fiber-reinforced concrete under water saturation conditions. The aim of this study was to determine the influence of polymer components and fiber reinforcement on changes in concrete strength under increased and prolonged exposure to moisture. A comparative assessment of the static and impact strength of concrete samples in dry and water-saturated conditions was conducted. It was found that the addition of polymeric materials reduces water absorption and increases the impact strength of concrete. Their combined use with fibers ensures the preservation of strength properties in conditions of high concrete humidity. The results can be used in the development of moisture-resistant concrete compositions for hydraulic structures and other facilities operating in aquatic environments. Full article

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

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28 pages, 3694 KB

Open AccessArticle

Improving Energy Efficiency in Hotels Through Evolutionary Digital Twin Technology: A Conceptual Framework and Empirical Evidence

by Rosana W. M. Wong and Becky P. Y. Loo

Buildings 2025, 15(24), 4406; https://doi.org/10.3390/buildings15244406 - 5 Dec 2025

Abstract

This study investigates the use of digital twin technology, machine learning (ML), and artificial intelligence (AI) to improve energy efficiency. It focuses on the heating, ventilation and air conditioning (HVAC) systems in hotel buildings which rely on central air-conditioning 24/7 throughout the year [...] Read more.

This study investigates the use of digital twin technology, machine learning (ML), and artificial intelligence (AI) to improve energy efficiency. It focuses on the heating, ventilation and air conditioning (HVAC) systems in hotel buildings which rely on central air-conditioning 24/7 throughout the year for ensuring thermal comfort and air ventilation. We develop a three-phase digital twin framework illustrating the progression from monitoring to autonomous control. Using data from real-world deployment in a Hong Kong hotel since 2013, we evaluated the evolution of digital twin applications from the Fixed Mode, to the Energy Optimisation Solution (EOS) Mode, finally to an AI-driven autonomous system. Leveraging 17,520 hourly data points from 1416 Internet of Things sensors, we relate digital twin features to environmental benefits based on energy consumption and Energy Efficiency Ratio (EER). For energy consumption, the AI Mode achieves the lowest daily energy consumption, averaging 841.94 kWh, which was 21.91% lower than Fixed mode and 50.42% lower than EOS mode. Under real-world conditions, the AI-driven autonomous digital twin improved EER by 6.2% over EOS and 2.9% over the Fixed Mode, confirming its superior thermal efficiency. The results demonstrate the benefits of combining digital twins with AI to enable intelligent, scalable, and energy-efficient buildings. Full article

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

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26 pages, 2228 KB

Open AccessArticle

Housing-Performance Atlas of Baltimore Row Homes: Archetype-Based Multi-Hazard Baseline of Energy, Heat, Survivability, and Durability

by Alex G. Nwosu, Bello Mahmud Zailani and James G. Hunter

Buildings 2025, 15(24), 4405; https://doi.org/10.3390/buildings15244405 - 5 Dec 2025

Abstract

Baltimore’s historic row-home neighborhoods face escalating risks to energy, heat, and durability under intensifying climate stress. This study develops a Housing-Performance Atlas that quantifies multi-hazard performance for eight representative archetypes using DesignBuilder/EnergyPlus Version 7.3.1.003, under Baltimore TMY3 boundary conditions. Performance is evaluated across [...] Read more.

Baltimore’s historic row-home neighborhoods face escalating risks to energy, heat, and durability under intensifying climate stress. This study develops a Housing-Performance Atlas that quantifies multi-hazard performance for eight representative archetypes using DesignBuilder/EnergyPlus Version 7.3.1.003, under Baltimore TMY3 boundary conditions. Performance is evaluated across the following four adaptation domains: energy use intensity, passive survivability during 72 h outage events, roof overheating exposure (>150 °F exceedance hours), and material service life derived from ISO 15686 and synthesized into Lean and Full Deficit Indices for comparative resilience ranking. Results show that EUI ranged from 46.7 to 67.6 kBtu ft⁻²·yr⁻¹, survivability from 0 to 23 h, and roof temperatures exceeded 150 °F for 150–210 h, shortening roof service life by up to 10 years. Composite Lean and Full Deficit Indices ranged 7.8–92.4, ranking Model 5 (end-unit, flat roof, two-story with basement) as the most resilient configuration and Model 8 (end-unit, pitched roof, three-story above-grade) as the least resilient due to compounded overheating and energy losses. Heat-related domains accounted for nearly 70% of overall resilience deficits, confirming thermal safety and roof reflectivity as retrofit priorities. The Housing-Performance Atlas establishes a reproducible diagnostic framework linking simulation, service life, and resilience metrics to guide cost-effective, climate-responsive retrofits in Baltimore’s aging urban housing stock. Full article

(This article belongs to the Special Issue Innovative Approaches to Climate-Responsive Building Design: Advancing Resilience and Sustainability in the Built Environment)

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29 pages, 26801 KB

Open AccessArticle

Renewal Design of Architectural Facade Features in the Shantou Xiaogongyuan Historic District Based on Deep Learning

by Wanying Yan, Tukun Wang and Cuina Zhang

Buildings 2025, 15(24), 4404; https://doi.org/10.3390/buildings15244404 - 5 Dec 2025

Abstract

The Shantou Xiaogongyuan Historic District is a significant cultural symbol of the “Century-Old Commercial Port,” embodying the historical memory of the Chaoshan diaspora culture and modern trade. However, amid rapid urbanization, the area faces challenges such as the degradation of architectural façade styles, [...] Read more.

The Shantou Xiaogongyuan Historic District is a significant cultural symbol of the “Century-Old Commercial Port,” embodying the historical memory of the Chaoshan diaspora culture and modern trade. However, amid rapid urbanization, the area faces challenges such as the degradation of architectural façade styles, the erosion of historical features, and inefficiencies in traditional restoration methods, often resulting in renovated façades that exhibit “form resemblance but spirit divergence.” To address these issues, this study proposes a method integrating computer vision and generative design for historical building façade renewal. Focusing on the arcade buildings in the Xiaogongyuan District, an intelligent façade generation system was developed based on the pix2pix model, a type of Conditional Generative Adversarial Network (CGAN). A dataset of 200 annotated images was constructed from 200 field-collected façade samples, including Functional Semantic Labeling (FSL) diagrams and Building Elevation (BE) diagrams. After 800 training epochs, the model achieved stable convergence, with the generated schemes achieving compliance rates of 80% in style consistency, 60% in structural integrity, and 70% in authenticity. Additionally, a WeChat mini-program was developed, capable of generating façade drawings in an average of 3 s, significantly improving design efficiency. The generated elevations are highly compatible and can be directly imported into third-party modeling software for quick 3D visualization. In a practical application at the intersection of Shangping Road and Zhiping Road, the system generated design alternatives that balanced historical authenticity and modern functionality within hours, far surpassing the weeks required by traditional methods. This research establishes a reusable technical framework that quantifies traditional craftsmanship through artificial intelligence, offering a viable pathway for the cultural revitalization of the Xiaogongyuan District and a replicable systematic approach for AI-assisted renewal of historic urban areas. Full article

(This article belongs to the Special Issue Practice and Application of Artificial Intelligence in Built Environment)

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24 pages, 6004 KB

Open AccessArticle

Influence of Backfill Soil on the Uplift Bearing Capacity of Prefabricated Foundations for Temporary Transition Towers

by Qingyu Meng, Hanyu Ning, Keqin Yan, Shufeng Long and Mengxin Kang

Buildings 2025, 15(24), 4403; https://doi.org/10.3390/buildings15244403 - 5 Dec 2025

Abstract

In response to the non-reusable nature and prolonged construction period of traditional foundations for temporary and transitional towers, this paper designs a fully reusable all-metal prefabricated foundation for 35 kV–110 kV transmission lines. The uplift bearing capacity of the fully metallic prefabricated foundation [...] Read more.

In response to the non-reusable nature and prolonged construction period of traditional foundations for temporary and transitional towers, this paper designs a fully reusable all-metal prefabricated foundation for 35 kV–110 kV transmission lines. The uplift bearing capacity of the fully metallic prefabricated foundation was investigated through a series of eight reduced-scale model tests (scale 1:3). Weathered sand and silty clay were selected as backfill materials, with relative density and foundation embedment depth as test variables. The load–displacement curves were plotted, and the ultimate uplift capacity was determined based on the load corresponding to the onset of a sharp transition in these curves. The test results demonstrated that the ultimate uplift capacity of foundations with weathered sand backfill was significantly superior to that of counterparts with silty clay under comparable conditions. Specifically, at an embedment depth of 1.2 m and high relative density, the ultimate load of the weathered sand backfill was 33.3% higher than that of the silty clay backfill. The ultimate uplift capacity increased markedly with higher relative density. When the degree of compaction increased from 0.7 to 0.9, the ultimate capacity of the weathered sand backfill increased by 100.0%, substantially exceeding the 30.4% increase observed for the silty clay backfill. Furthermore, the ultimate capacity exhibited greater sensitivity to the embedment depth in weathered sand. As the embedment depth increased from 0.5 m to 1.2 m, the ultimate capacity of the weathered sand backfill increased by 191%, far surpassing the 114% increase for the silty clay backfill. This study provides experimental evidence and theoretical references for the design and construction of assembled foundations for temporary tower structures. The conclusions of this study are based on model test conditions and require further verification through prototype tests and numerical simulation. Full article

(This article belongs to the Special Issue Disaster Prevention and Resilient Structures in Engineering Construction)

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18 pages, 9518 KB

Open AccessArticle

Toward Zero-Carbon Concrete: Alkali Activation of Ladle Furnace Slag Using Cement Kiln Dust

by Aleksandar Nikolov, Nicolai B. Jordanov, Iliyan Djobov and Alexandar Karamanov

Buildings 2025, 15(24), 4402; https://doi.org/10.3390/buildings15244402 - 5 Dec 2025

Abstract

This study investigates the potential of producing zero-clinker, alkali-activated binders and concrete entirely from industrial by-products—ladle furnace slag (LFS), coal ash (CA), and cement kiln dust (CKD). The incorporation of CKD enhanced the workability and compressive strength properties of the alkali-activated mixtures, with [...] Read more.

This study investigates the potential of producing zero-clinker, alkali-activated binders and concrete entirely from industrial by-products—ladle furnace slag (LFS), coal ash (CA), and cement kiln dust (CKD). The incorporation of CKD enhanced the workability and compressive strength properties of the alkali-activated mixtures, with the highest mechanical properties at 20% CKD addition. XRD, FTIR, and SEM analyses confirmed the formation of hydrocalumite, indicating improved hydration and microstructural densification. Mortar and concrete produced using the eco-cement reached 28-day strengths of 34.5 MPa and 32.6 MPa, corresponding to concrete class C20/25. These findings demonstrate the feasibility of manufacturing 100% waste-based construction materials suitable for sustainable, non-reinforced applications. Full article

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

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14 pages, 4696 KB

Open AccessArticle

Regulatory Gap Versus Performance Reality: Thermal Assessment of a Social Housing Module in the Peruvian Andes

by Emilio Palomino-Olivera, Miriam Ancco-Peralta, Víctor Salas Velásquez, Enrique Mejia-Solis and Edwin Gudiel Rodriguez

Buildings 2025, 15(24), 4401; https://doi.org/10.3390/buildings15244401 - 5 Dec 2025

Abstract

In high-altitude regions of the Global South, social housing programs are essential for mitigating vulnerability to low temperatures, but their standardized designs often fail to meet thermal performance codes. This study evaluates a “Sumaq Wasi” adobe housing module in the Peruvian Andes (Kunturkanki, [...] Read more.

In high-altitude regions of the Global South, social housing programs are essential for mitigating vulnerability to low temperatures, but their standardized designs often fail to meet thermal performance codes. This study evaluates a “Sumaq Wasi” adobe housing module in the Peruvian Andes (Kunturkanki, 4237 m a.s.l.) during the 2023 frost season. We comparatively applied the 2014 and 2022 draft versions of the Peruvian standard EM.110 to assess the building envelope’s thermal transmittance and condensation risk, benchmarking monitored indoor temperatures against adaptive comfort models. The results revealed widespread non-compliance with thermal transmittance limits, especially for the roof and floor, although condensation risk was low. While indoor temperatures failed to meet conventional standards, they aligned with regionally adapted comfort ranges. We conclude that the standardized module design is insufficient for local climatic demands and argue that social housing policies must evolve, balancing regulatory stringency with context-aware bioclimatic design to be effective. Full article

(This article belongs to the Topic Energy Systems in Buildings and Occupant Comfort)

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7 pages, 170 KB

Open AccessEditorial

Development of Underground Space for Engineering Applications

by Chun Zhu, Renjie Nie, Jun Lu, Zhen Wang and Fei Wu

Buildings 2025, 15(24), 4400; https://doi.org/10.3390/buildings15244400 - 5 Dec 2025

Abstract

Faced with multiple challenges, such as scarce land resources, traffic congestion, and natural disasters, underground space has become a critical pathway for high-density cities to achieve sustainable development and enhance resilience [...] Full article

(This article belongs to the Topic Development of Underground Space for Engineering Application)

21 pages, 5074 KB

Open AccessArticle

Experimental Investigation of Metamaterial-Inspired Periodic Foundation Systems with Embedded Piezoelectric Layers for Seismic Vibration Attenuation

by Mehmet Furkan Oz, Atila Kumbasaroglu, Hakan Yalciner, Nurettin Korozlu, Yunus Babacan, Fulya Esra Cimilli Çatır and Done Sayarcan

Buildings 2025, 15(24), 4399; https://doi.org/10.3390/buildings15244399 - 5 Dec 2025

Abstract

Seismic metamaterial-inspired periodic foundations have emerged as promising vibration-mitigation concepts capable of attenuating seismic wave propagation within specific frequency bands. This study presents an experimental investigation on the dynamic response of periodic foundation configurations, with and without embedded piezoelectric layers, to evaluate their [...] Read more.

Seismic metamaterial-inspired periodic foundations have emerged as promising vibration-mitigation concepts capable of attenuating seismic wave propagation within specific frequency bands. This study presents an experimental investigation on the dynamic response of periodic foundation configurations, with and without embedded piezoelectric layers, to evaluate their vibration-attenuation characteristics. The experimental program employed a shake table driven by a 0.75 kW servo motor and included excitation step counts of 3000, 4000, and 5000. Accelerometers mounted on the specimen surfaces recorded vibration data at 80 ms intervals. Three foundation configurations were tested: (i) a conventional reinforced concrete block, (ii) a one-dimensional periodic foundation composed of alternating concrete and rubber layers, and (iii) a periodic foundation incorporating piezoelectric modules. Time-domain and frequency-domain analyses showed that the periodic foundations achieved notable reductions in both peak and RMS accelerations, especially near resonance frequencies. The configuration, including piezoelectric layers, exhibited similar attenuation performance while also generating measurable instantaneous voltage outputs under vibration. However, these voltage peaks—reaching a maximum of 1.64 V—represent only a laboratory-scale, proof-of-concept demonstration of electromechanical coupling rather than a practical or continuous form of energy harvesting, given the inherently sporadic nature of seismic excitation. Overall, the results confirm that the tested system is not a full metamaterial in the classical sense but rather a metamaterial-inspired periodic arrangement capable of inducing band-gap-based vibration attenuation. The inclusion of piezoelectric elements provides auxiliary sensing and micro-energy-generation capabilities, offering a preliminary foundation for future multifunctional seismic-protection concepts. Full article

(This article belongs to the Special Issue Innovative Materials and Technologies for Sustainable Structural Engineering)

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22 pages, 4620 KB

Open AccessArticle

Evaluation of Tensile Strength, Elastic Modulus, Density, and Fiber Content of Glass Fiber-Reinforced Polymer Rebars During and After Exposure to High Temperatures

by Rafael Trevisan, Fernanda Pacheco, Roberto Christ, Hinoel Zamis Ehrenbring, Giovanna Menegussi Portela and Bernardo Tutikian

Buildings 2025, 15(24), 4398; https://doi.org/10.3390/buildings15244398 - 5 Dec 2025

Abstract

This study investigated the changes in the physical and mechanical properties of glass fiber-reinforced polymer (GFRP) rebars during and after exposure to elevated temperatures. The specimens were tested at 23 °C (ambient), 150 °C, 200 °C, 250 °C, 300 °C, and 350 °C [...] Read more.

This study investigated the changes in the physical and mechanical properties of glass fiber-reinforced polymer (GFRP) rebars during and after exposure to elevated temperatures. The specimens were tested at 23 °C (ambient), 150 °C, 200 °C, 250 °C, 300 °C, and 350 °C in an electric kiln coupled to a universal testing machine, without exposure to flames. The mechanical properties evaluated were the tensile strength and modulus of elasticity. After exposure, the surface damage was examined using scanning electron microscopy (SEM), and resin loss was quantified through fiber content tests. At ambient temperature, the average tensile strength and modulus of elasticity of the rebars were 956.4 MPa and 44.7 GPa, respectively. Damage observed during heating was more severe than that observed after heating and subsequent cooling. At 350 °C, up to 37% of the tensile strength was lost during heating, whereas the maximum reduction in modulus of elasticity was 8.3%, indicating that the fibers themselves were not significantly compromised by heat. After exposure and cooling, the maximum reduction in tensile strength was less than 1% (after exposure to 150 °C), while the modulus of elasticity exhibited a 7.9% decrease (after exposure to 200 °C). The glass transition temperature was measured at 101.7 °C. SEM analysis revealed signs of resin degradation caused by heat, including superficial damage, microcracks, reduced resin cover over the fibers, and ruptured fibers. Fiber content tests after exposure demonstrated a direct correlation between reduced fiber content and the decline in mechanical properties. The behavior of GFRP rebars after heating and cooling can provide important insights for assessing structural safety in post-fire buildings, since natural cooling led to partial resin recovery and improvements in mechanical performance. Full article

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

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