Buildings

22 pages, 15998 KB

Open AccessArticle

Seismic Performance of Corroded Precast Concrete Bridge Piers with Grouted Sleeve Connections Retrofitted by Ultra-High-Performance Concrete Shells

by Long Ma, Xiangtong Wu, Hao Tian and Wenting Yuan

Buildings 2026, 16(4), 694; https://doi.org/10.3390/buildings16040694 (registering DOI) - 7 Feb 2026

Abstract

Grouted sleeve connections (GSCs) are widely used in precast concrete (PC) bridge piers due to their convenience in construction and reliable structural performance. Corrosion-induced damage significantly compromises the seismic integrity of PC bridge piers with GSCs, making effective rehabilitation urgent. However, there is [...] Read more.

Grouted sleeve connections (GSCs) are widely used in precast concrete (PC) bridge piers due to their convenience in construction and reliable structural performance. Corrosion-induced damage significantly compromises the seismic integrity of PC bridge piers with GSCs, making effective rehabilitation urgent. However, there is a scarcity of research addressing this specific retrofit need. To bridge this gap, this work systematically investigates the efficacy of ultra-high-performance concrete (UHPC) encasement in retrofitting the quasi-static seismic resilience of corroded GSC piers. Numerical analyses were conducted using OpenSEES, in which the GSCs were equivalently modeled by determining their yield strength and cross-sectional area. Three corrosion ratios of the GSCs (20%, 40%, and 60%) were considered. The effects of UHPC compressive strength (100 MPa, 120 MPa, 150 MPa) and different retrofit heights on the quasi-static seismic performance of the bridge piers were systematically investigated. The results reveal that corrosion of the GSCs markedly compromises the quasi-static seismic behavior of PC bridge piers, notably reducing both the bearing capacity and energy dissipation capacity. Retrofitting with UHPC shells effectively enhances the yield force, peak force, yield stiffness, and energy dissipation capacity of the piers. These improvements become more substantial with higher UHPC strength and greater retrofit height. Overall, the results underscore the significant detrimental effect of sleeve corrosion on quasi-static seismic performance and confirm UHPC retrofitting as a viable and effective mitigation approach. Full article

(This article belongs to the Section Building Structures)

► Show Figures

Figure 1

33 pages, 8324 KB

Open AccessArticle

Numerical and Theoretical Investigation into the Global Stability Behaviour of Glulam Gridshells Stiffened by Prestressed Cables

by Xin Wang, Zhaodong Yin, Jian Ma, Wenping Qin, Yang Yang and Pengcheng Li

Buildings 2026, 16(4), 693; https://doi.org/10.3390/buildings16040693 (registering DOI) - 7 Feb 2026

Abstract

As a low-carbon and lightweight material, glulam is increasingly being used in spatial gridshells. However, these glulam gridshells are prone to instability owing to the material properties of glulam. In this study, to enhance the overall stability behaviour, a prestressed cable system was [...] Read more.

As a low-carbon and lightweight material, glulam is increasingly being used in spatial gridshells. However, these glulam gridshells are prone to instability owing to the material properties of glulam. In this study, to enhance the overall stability behaviour, a prestressed cable system was introduced to the ordinary glulam gridshell to form a novel prestressed cable-braced glulam gridshell. Extensive finite element simulations were conducted to examine the mechanical performance of these novel gridshells. This paper analyses how variations in structural parameters impact the stability performance of the shell. Furthermore, an approximate formula is developed to assess the load carrying capacity. This formula is established by integrating theoretical derivations with numerical simulations. We have thus demonstrated that the stability behaviour of traditional glulam gridshells can be significantly improved by the introduction of prestressed cable systems, and the proposed evaluation formula is accurate enough for the load carrying capacity prediction of prestressed cable-braced glulam gridshell. Full article

(This article belongs to the Special Issue The Latest Research on Building Materials and Structures)

► Show Figures

Figure 1

21 pages, 4069 KB

Open AccessArticle

A Model of a Gravity Dam Reservoir Based on a New Concrete-Simulating Microparticle Mortar

by Zeye Feng, Yanhong Zhang, Xiao Hu, Hongdong Zhu and Guoliang Xing

Buildings 2026, 16(4), 692; https://doi.org/10.3390/buildings16040692 (registering DOI) - 7 Feb 2026

Abstract

To address the challenge that traditional dam model materials are difficult to simultaneously meet the requirements of microstructural similarity, dynamic damage simulation, and environmental friendliness, a novel microparticle mortar simulated concrete was developed. This new material consists of cement, sand, gypsum, mineral oil, [...] Read more.

To address the challenge that traditional dam model materials are difficult to simultaneously meet the requirements of microstructural similarity, dynamic damage simulation, and environmental friendliness, a novel microparticle mortar simulated concrete was developed. This new material consists of cement, sand, gypsum, mineral oil, water, and baryte sand. Through systematic material mechanical tests, the effects of each component on the material’s strength, density, and elastic modulus were revealed, and the optimal mix ratio was determined. This enabled precise control of low elastic modulus and had a high density, while the material is environmentally friendly, non-toxic, and compatible with direct contact with natural water. Its mechanical properties are highly similar to those of the prototype concrete. Based on a 1:70 geometric scale, a shaking table model test of the concrete gravity dam-reservoir system was conducted. The dynamic response and damage evolution under empty and full reservoir conditions were compared and analyzed. The study shows that this material can accurately simulate the stress-strain relationship and failure mode of prototype concrete. Under the full reservoir condition, the dam’s fundamental frequency showed only a 2.72% deviation from the numerical simulation, and as the seismic excitation amplitude increased, the changes in the fundamental frequency effectively reflected the accumulation of damage. Under the design seismic motion, the measured accelerations and stress responses for both empty and full reservoir conditions were in good agreement with numerical calculations. Under overload conditions, the acceleration amplification factor at the dam crest decreased with damage accumulation, and the dam neck was identified as the seismic weak zone. As the peak ground acceleration (PGA) increased from 0.15 g to 0.70 g, the fundamental frequency changes effectively reflected the damage accumulation process in the dam, while the hydrodynamic pressure at the dam heel showed a linear increase (457% increase). The experimentally measured hydrodynamic pressure distribution was between the rigid dam and elastic dam hydrodynamic pressures, reflecting the real fluid-structure interaction effect. This study provides a reliable material solution and data support for dam seismic physical model testing. Full article

(This article belongs to the Special Issue Seismic Performance and Durability of Engineering Structures)

► Show Figures

Figure 1

22 pages, 3412 KB

Open AccessReview

Review of Health Monitoring and Intelligent Fault Diagnosis for High-Strength Bolts: Failure Mechanisms, Multi-Modal Sensing, and Data-Driven Approaches

by Yingjie Wang, Guanghui Chu, Zhifang Sun, Fei Yang, Jun Yang, Xiaoli Sun, Yi Zhao and Shuai Teng

Buildings 2026, 16(4), 691; https://doi.org/10.3390/buildings16040691 (registering DOI) - 7 Feb 2026

Abstract

High-strength bolted connections are fundamental load-bearing components in critical engineering infrastructures such as wind turbines, bridges, and heavy machinery. Under complex service environments involving dynamic loading, vibration, corrosion, and temperature variations, bolts are prone to interacting failure mechanisms, including fatigue fracture, corrosion-assisted cracking, [...] Read more.

High-strength bolted connections are fundamental load-bearing components in critical engineering infrastructures such as wind turbines, bridges, and heavy machinery. Under complex service environments involving dynamic loading, vibration, corrosion, and temperature variations, bolts are prone to interacting failure mechanisms, including fatigue fracture, corrosion-assisted cracking, hydrogen embrittlement, and progressive preload loss, which pose significant challenges for reliable condition monitoring and early fault diagnosis. This review provides a structured synthesis of recent advances in bolt health monitoring and intelligent fault diagnosis. A unified framework is established to link multi-physics failure mechanisms with multi-modal sensing technologies and data-driven diagnostic methods. Key sensing approaches—such as piezoelectric impedance techniques, ultrasonic phased array inspection, and computer vision-based monitoring—are critically reviewed in terms of their physical principles, diagnostic capabilities, and limitations. Furthermore, the transition from traditional model-based and signal-processing-driven methods to machine learning- and deep learning-based approaches is examined, with emphasis on multi-modal data fusion, real-time monitoring, and lifecycle-oriented health management enabled by IoT and digital twin technologies. Finally, key challenges and future research directions toward robust and scalable intelligent bolt health management systems are outlined. This review’s primary contribution lies in establishing a novel, integrated framework that links failure physics to sensing and diagnosis, thereby providing a structured roadmap for transitioning from isolated component monitoring to lifecycle-oriented, intelligent health management systems for critical bolted connections. Full article

(This article belongs to the Special Issue Advances in Building Structure Analysis and Health Monitoring)

► Show Figures

Figure 1

21 pages, 1024 KB

Open AccessArticle

A Conceptual AI-Based Framework for Clash Triage in Building Information Modeling (BIM): Towards Automated Prioritization in Complex Construction Projects

by Andrzej Szymon Borkowski and Alicja Kubrat

Buildings 2026, 16(4), 690; https://doi.org/10.3390/buildings16040690 (registering DOI) - 7 Feb 2026

Abstract

Effective clash management is critical to the success of complex construction projects, yet BIM coordinators face severe information overload when modern detection tools generate thousands or even millions of collision reports, making interdisciplinary coordination increasingly difficult. This article presents a conceptual framework for [...] Read more.

Effective clash management is critical to the success of complex construction projects, yet BIM coordinators face severe information overload when modern detection tools generate thousands or even millions of collision reports, making interdisciplinary coordination increasingly difficult. This article presents a conceptual framework for using AI for collision triage in a Building Information Modeling (BIM) environment. Previous approaches have focused mainly on collision detection itself and simple, rule-based prioritization, rarely exploiting the potential of Artificial Intelligence (AI) methods for post-processing of results, which constitutes the main innovation of this work. The proposed framework describes a modular system in which collision detection results and data from BIM models, schedules (4D), and cost estimates (5D) are processed by a set of AI components, offering adaptive, data-driven decision support unlike static rule-based methods. These include: a classifier that filters out irrelevant collisions (noise), algorithms that group recurring collisions into single design problems, a model that assesses the significance of collisions by determining a composite ‘AI Triage Score’ indicator, and a module that assigns responsibility to the appropriate trades and process participants. The framework leverages supervised machine learning methods (gradient boosting algorithms, selected for their effectiveness with tabular data) for noise filtering, density-based clustering (HDBSCAN, chosen for its ability to detect clusters of varying densities without predefined cluster count) for clash aggregation, and multi-criteria scoring models for priority assessment. The article also discusses a potential way to integrate the framework into the existing BIM workflow and possible scenarios for its validation based on case studies and expert evaluation. The proposed conceptual framework represents a step towards moving from manual, intuitive collision triage to a data- and AI-based approach, which can contribute to increased coordination efficiency, reduced risk of errors, and better use of design resources. As a conceptual study, the framework provides a foundation for future empirical validation and its limitations include dependency on historical training data availability and the need for calibration to project-specific contexts. Full article

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

30 pages, 6285 KB

Open AccessArticle

Prediction of the Extreme Dynamic Amplification Factor Based on Bayesian Peaks-Over-Threshold–Generalized Pareto Distribution Method and Random Traffic–Bridge Interaction

by Wasyhun Afework Kechine, Bin Wang, Cuipeng Xia and Yongle Li

Buildings 2026, 16(4), 689; https://doi.org/10.3390/buildings16040689 (registering DOI) - 7 Feb 2026

Abstract

The accurate prediction of extreme dynamic amplification factor (DAF) values is significantly important to ensure a long-term safety assessment of bridges under stochastic vehicular loading. However, predicting extreme DAFs is challenging due to traffic randomness, road roughness variability, and nonlinear vehicle–bridge interaction (VBI) [...] Read more.

The accurate prediction of extreme dynamic amplification factor (DAF) values is significantly important to ensure a long-term safety assessment of bridges under stochastic vehicular loading. However, predicting extreme DAFs is challenging due to traffic randomness, road roughness variability, and nonlinear vehicle–bridge interaction (VBI) effects. This study presents an integrated framework for extreme DAF prediction for simply supported bridges by combining stochastic traffic–bridge interaction simulations with Bayesian updating and a Peaks-Over-Threshold–Generalized Pareto Distribution (POT–GPD) model. A coupled VBI model is developed, incorporating cellular automaton-based traffic flow, multi-axle nonlinear vehicle dynamics, finite-element bridge modeling, and stochastic road roughness profiles. A new DAF definition based on dynamic displacement difference is proposed to better represent dynamic effects. DAF samples obtained from VBI simulations under different road roughness levels are analyzed using the POT method, with GPD parameters estimated through maximum likelihood and Bayesian inference. Extreme DAFs corresponding to different return periods are then determined. The results indicate that extreme DAF values increase with worsening road roughness and longer return periods and that the Bayesian POT–GPD approach effectively captures tail behavior while providing reliable uncertainty quantification for extreme DAF prediction. Full article

(This article belongs to the Section Building Structures)

19 pages, 2019 KB

Open AccessArticle

Shear Correction Factor for Porous Eco-Materials: Mechanical Characterization of a Heterogeneous Medium

by Julia Graczyk, Tomasz Gajewski and Tomasz Garbowski

Buildings 2026, 16(4), 688; https://doi.org/10.3390/buildings16040688 (registering DOI) - 7 Feb 2026

Abstract

Classical formulas for the shear correction factor k_s, typically derived for homogeneous continua, are unsuitable for porous media exhibiting local density gradients, irregular pore morphologies, and spatially varying stiffness. This paper presents a generalized analytical–numerical methodology for evaluating the shear correction [...] Read more.

Classical formulas for the shear correction factor k_s, typically derived for homogeneous continua, are unsuitable for porous media exhibiting local density gradients, irregular pore morphologies, and spatially varying stiffness. This paper presents a generalized analytical–numerical methodology for evaluating the shear correction factor in a wide class of porous eco-materials. The approach is based on the strain energy equivalence principle and uses a continuous stiffness model that reflects density-dependent elastic properties. A voxel-based microstructural representation is employed to validate the analytical predictions and to quantify the influence of heterogeneity on the shear stress distribution. Perlite is used as a representative case study, demonstrating how classical homogeneous formulas may produce errors exceeding 40%, while the proposed method provides significantly improved agreement with numerical benchmarks. The framework is applicable to a broad range of porous materials and offers a consistent basis for predicting transverse shear stiffness in lightweight fillers, thermal barriers, and fire-protective building components where shear deformation is critical. Full article

27 pages, 4548 KB

Open AccessReview

Indoor Odor Pollution: An Interdisciplinary Review from Sources to Control and an Intelligent Building Environment Management Framework

by Ning Liu, Zhanwu Ning, Yiting Jia, Yifan Ren, Weijie Liu, Yanni Zhang, Peng Zhao, Peng Sun, Jingjing Zhang and Jinhua Liu

Buildings 2026, 16(4), 687; https://doi.org/10.3390/buildings16040687 (registering DOI) - 7 Feb 2026

Abstract

Indoor environmental quality directly affects public health and quality of life, among which odor pollution is one of the primary drivers of indoor environmental complaints. Traditional research and management approaches, which rely predominantly on mass concentrations of individual chemical compounds, are fundamentally inadequate [...] Read more.

Indoor environmental quality directly affects public health and quality of life, among which odor pollution is one of the primary drivers of indoor environmental complaints. Traditional research and management approaches, which rely predominantly on mass concentrations of individual chemical compounds, are fundamentally inadequate for addressing the inherent sensory complexity, dynamic evolution, and subjective perception of indoor odors. Through a systematic literature review, this paper for the first time establishes an integrated research framework for indoor odor pollution across the whole-life-cycle management of the built environment, structured around “source–evolution–evaluation–control”. This framework systematically analyzes emission characteristics of building-related pollution sources, revealing the profound impact of indoor dynamic chemical and biological transformation processes on odor properties. Sensory analysis, instrumental measurements, and intelligent sensing approaches are critically compared in terms of their underlying principles and application boundaries. From an engineering perspective, the effectiveness and limitations of source prevention, ventilation dilution, and terminal purification strategies are comprehensively evaluated. The analysis demonstrates that effective indoor odor management must transcend passive and fragmented mitigation practices, and that its future development depends on the deep integration of environmental chemistry, sensory science, materials science, and artificial intelligence. Finally, this review proposes that by constructing regulation systems based on real-time sensing, digital twins, and intelligent decision-making, indoor odor management can fundamentally shift from reactive complaint-driven responses to proactive health-oriented protection. This paradigm transformation provides a systematic theoretical foundation and a technological roadmap for achieving healthy, comfortable, and sustainable building environments. Full article

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

► Show Figures

Figure 1

26 pages, 13142 KB

Open AccessArticle

Experimental and Numerical Investigations of Blast Resistance of Fiber-Reinforced Concrete Slabs

by Pradeep Tharanga Kumara Rathnayaka, Jin-Su Son, Jae-Won Kwak, Sun-Jae Yoo and Jin-Young Lee

Buildings 2026, 16(4), 686; https://doi.org/10.3390/buildings16040686 (registering DOI) - 7 Feb 2026

Abstract

Despite extensive research on blast-resistant concrete structures, a clear scientific deficiency remains in the quantitative understanding of how fiber-reinforced concrete slabs behave under blast loading, particularly when experimental and numerical investigations are not conducted together under identical loading conditions. Existing studies often focus [...] Read more.

Despite extensive research on blast-resistant concrete structures, a clear scientific deficiency remains in the quantitative understanding of how fiber-reinforced concrete slabs behave under blast loading, particularly when experimental and numerical investigations are not conducted together under identical loading conditions. Existing studies often focus on either conventional reinforced concrete or isolated material systems, providing limited validation of comparative blast performance across different fiber-reinforced concretes. This study addresses this gap by investigating the blast resistance performance of four types of reinforced concrete slabs: normal concrete (NC), ultra-high-performance fiber-reinforced concrete (UHPFRC), organic fiber-reinforced high-performance concrete (O-HPC), and basalt FRP-sheet-strengthened slurry-infiltrated fiber concrete (F-SIFCON), using full-scale blast experiments and validated numerical simulations conducted with ANSYS Explicit Dynamics. Blast tests were performed to obtain time histories of reflected pressure, displacement, acceleration, reaction force, and internal energy. The influence of different fiber systems and FRP strengthening on dynamic response and failure mechanisms was systematically analyzed. The numerical models showed good agreement with experimental measurements, confirming their reliability. The results indicate that the normal concrete slab exhibited brittle failure and poor blast resistance, whereas the F-SIFCON slab demonstrated the best overall performance. Compared with the normal concrete slab, the F-SIFCON slab achieved approximately a 47% reduction in maximum displacement, a 56% increase in peak reaction force, and the highest internal energy absorption of 236 kJ. The UHPFRC and O-HPC slabs also showed improved blast resistance, although with different post-peak response characteristics. These findings demonstrate that hybrid fiber reinforcement combined with FRP strengthening can significantly enhance the blast resistance of concrete slabs and that coupled experimental–numerical approaches provide a robust framework for evaluating structural performance under extreme dynamic loading. Full article

(This article belongs to the Special Issue Study on the Durability of Construction Materials and Structures)

► Show Figures

Figure 1

36 pages, 4984 KB

Open AccessArticle

Evaluation of Building Design Variants in Early Phases on the Basis of Adaptive Detailing Strategies

by Daniel Napps, Johannes Staudt, Ueli Saluz, Xia Chen, Daniel Steiner, Chujun Zong, Fatma Deghim, Werner Lang, Philip Geyer, Martina Schnellenbach-Held, Frank Petzold, André Borrmann and Markus König

Buildings 2026, 16(4), 685; https://doi.org/10.3390/buildings16040685 (registering DOI) - 7 Feb 2026

Abstract

Design decisions made in the early phases of the design process have a significant impact on the eventual performance of the completed building. Currently, computer-assisted methods offer limited support during the crucial stages of creating, assessing and refining design variants. This paper presents [...] Read more.

Design decisions made in the early phases of the design process have a significant impact on the eventual performance of the completed building. Currently, computer-assisted methods offer limited support during the crucial stages of creating, assessing and refining design variants. This paper presents an integrated framework combining computer-aided design processes and performance-based evaluation methods to support a non-linear, iterative design process. The framework integrates spatial metrics (e.g., layout and design similarity), structural metrics (e.g., feasible systems and material quantities) and environmental–energy metrics (e.g., heating demand) to provide transparent, quantitative and qualitative feedback for early-stage decision-making. Applying the framework allowed for the incorporation of structural, environmental and spatial assessments early in the process. The design assistance framework is graphically represented using business process model and notation (BPMN), which facilitates communication between process design and implementation. A real-world, mixed-use building scenario illustrates how the individual methods interact to streamline the decision-making process for architects. The framework guides the entire process, from design decisions to structural and performance-specific features, offering inspirational support for architects and practical assistance for structural engineers, sustainability experts and other professionals involved in early-stage building design. Full article

► Show Figures

Figure 1

34 pages, 5032 KB

Open AccessArticle

Strength Prediction of Concavely Curved Soffit RC Beams Strengthened with CFRP

by Khattab Al-Ghrery, Robin Kalfat, Riadh Al-Mahaidi and Nazar Oukaili

Buildings 2026, 16(3), 684; https://doi.org/10.3390/buildings16030684 (registering DOI) - 6 Feb 2026

Abstract

The utilisation of carbon fibre–reinforced polymers (CFRPs) has emerged as a promising method for enhancing the flexural performance of reinforced-concrete (RC) bridges. While extensive research has been conducted on CFRP systems implemented on flat soffit RC beams, further work is required to assess [...] Read more.

The utilisation of carbon fibre–reinforced polymers (CFRPs) has emerged as a promising method for enhancing the flexural performance of reinforced-concrete (RC) bridges. While extensive research has been conducted on CFRP systems implemented on flat soffit RC beams, further work is required to assess their effectiveness when applied to concavely curved soffit RC members. This paper uses finite element simulations to extend an experimental database on RC beams with curved soffits ranging from 5, 10, 15 and 20 mm/m strengthened using externally bonded FRP. Parametric studies into four different concrete strengths ranging from 25, 35, 48, 57 MPa and additional degrees of soffit curvature up to 50 mm/m were used to generate a total of 88 data points. Further, gene expression programming (GEP) was used to develop an empirical model correlating a capacity reduction factor applied to the maximum FRP strain required to produce intermediate-span crack-induced (IC) debonding for concavely curved soffit RC beams externally strengthened with CFRP. The results of the GEP model demonstrated that the model can be employed as an efficient tool for the prediction of the reduction in the flexural capacity of concavely curved soffit RC beams strengthened externally with NSM CFRP. Full article

(This article belongs to the Section Building Structures)

► Show Figures

Figure 1

21 pages, 3301 KB

Open AccessArticle

AI-Driven Seismic Fragility Assessment of RC Buildings: A Localized Comparison of RVS Methods in Bingol

by Sadık Varolgüneş and Abdulhalim Karaşin

Buildings 2026, 16(3), 683; https://doi.org/10.3390/buildings16030683 - 6 Feb 2026

Abstract

Rapid assessment of existing reinforced concrete (RC) buildings is essential for effective seismic risk mitigation, particularly in highly active regions such as Bingol, Turkiye. This study evaluates the local performance of three Rapid Visual Screening (RVS) methods—RBTY-2019, FEMA-P154, and IITK-GSDMA—using verified post-earthquake damage [...] Read more.

Rapid assessment of existing reinforced concrete (RC) buildings is essential for effective seismic risk mitigation, particularly in highly active regions such as Bingol, Turkiye. This study evaluates the local performance of three Rapid Visual Screening (RVS) methods—RBTY-2019, FEMA-P154, and IITK-GSDMA—using verified post-earthquake damage data from the 2003 Bingol Earthquake (SERU-2003). To overcome the limitations of traditional RVS approaches, an Artificial Neural Network (ANN) model was developed and trained with the same dataset to predict building damage levels based on structural deficiency parameters. The ANN achieved a regression coefficient above 0.90 and 100% consistency in test predictions, demonstrating superior accuracy and adaptability to local construction characteristics. A Local Scaling Function (LSF) was also proposed to translate RBTY-2019 performance scores into empirical damage states, achieving 100% consistency with observed data. The findings highlight the reliability of locally trained AI models and the importance of adapting national screening regulations to regional seismic experiences. This integrated ANN–RVS framework provides a practical, data-driven tool for local authorities to prioritize urban building stock and strengthen disaster risk management strategies. Full article

(This article belongs to the Special Issue Artificial Intelligence (AI) for Construction Risk Management)

35 pages, 6221 KB

Open AccessArticle

A Hybrid CNN–PINN–NSGA-II Framework for Physics-Consistent Surrogate Modeling of Reinforced Concrete Beams Incorporating Waste Fired Clay

by Yasin Onuralp Özkılıç, Memduh Karalar, Muhannad Riyadh Alasiri, Özer Zeybek and Sadik Alper Yildizel

Buildings 2026, 16(3), 682; https://doi.org/10.3390/buildings16030682 (registering DOI) - 6 Feb 2026

Abstract

This paper presents a physics-consistent hybrid surrogate framework for simulating the mechanical behavior of reinforced concrete beams that utilize waste fired clay (WFC) as a partial substitute for cement. The main contribution is the integration of empirically observed deformation behavior with physics-informed learning [...] Read more.

This paper presents a physics-consistent hybrid surrogate framework for simulating the mechanical behavior of reinforced concrete beams that utilize waste fired clay (WFC) as a partial substitute for cement. The main contribution is the integration of empirically observed deformation behavior with physics-informed learning to produce an interpretable, mechanically valid surrogate model. Full-field surface deformation fields were measured using Digital Image Correlation (DIC) under monotonic loading and processed through a convolutional neural network (CNN) to extract deformation- and crack-sensitive features. These features were integrated with experimentally measured stress–strain data within a Physics-Informed Neural Network (PINN) in which equilibrium and conditional constitutive monotonicity constraints were enforced through the loss function. A Non-Dominated Sorting Genetic Algorithm II (NSGA-II) was utilized as a downstream parametric exploration tool to examine trade-offs among maximum load capacity, material cost, and embodied CO₂ inside a constrained mixture-design space. Model interpretability was assessed by SHapley Additive exPlanations (SHAP), indicating that deformation-driven kinematic factors predominantly influence stress prediction, whereas WFC content and reinforcement parameters have a secondary, mixture-level impact. The resulting framework achieves enhanced predictive accuracy (R² = 0.969) relative to its individual components and operates as an offline, physics-calibrated surrogate rather than a real-time digital twin, providing a reliable and interpretable basis for structural assessment and sustainability-oriented design evaluation of WFC-modified reinforced concrete beams. Full article

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

► Show Figures

Figure 1

18 pages, 7010 KB

Open AccessArticle

Development and Experimental Study of a Novel Diaphragm Wall Joint with Retractable Shear Studs

by Yue Zhang, Changjiang Wang and Xiewen Hu

Buildings 2026, 16(3), 681; https://doi.org/10.3390/buildings16030681 - 6 Feb 2026

Abstract

Diaphragm walls are widely used for deep foundation pit support and permanent underground structures. The joints between adjacent panels are critical weak points, significantly influencing the overall deformation and stress distribution of the structure. To address the insufficient shear and tensile capacity of [...] Read more.

Diaphragm walls are widely used for deep foundation pit support and permanent underground structures. The joints between adjacent panels are critical weak points, significantly influencing the overall deformation and stress distribution of the structure. To address the insufficient shear and tensile capacity of existing diaphragm wall joints, this study proposes a novel rigid joint incorporating retractable shear studs. The joint features a straightforward and constructible design, primarily comprising retractable shear studs, H-section steel, and shear stud pop-out limit plates. By withdrawing the limit plates inserted into the H-section steel, the retractable shear studs mounted on the web automatically extend along their axis, penetrating into the adjacent reinforcement cage to form an intrusive lap joint. This mechanism effectively enhances the integrity and load-bearing capacity at the joint. To validate its mechanical performance, large-scale specimens featuring this new joint were fabricated and subjected to shear and tensile tests. The experimental results demonstrate that, compared to traditional H-section steel joints, the peak shear and tensile strengths of the proposed joint are increased by approximately 10 times and 16 times, respectively. These findings fully verify the excellent mechanical performance of the novel diaphragm wall joint structure. Full article

(This article belongs to the Special Issue Design, Construction and Maintenance of Underground Structures—2nd Edition)

► Show Figures

Figure 1

24 pages, 5677 KB

Open AccessArticle

Impact of Elevated Curing Temperatures on the Expansion Mechanism and Microstructure of Fly-Ash-Blended Cementitious Materials Incorporating HCSA

by Kai Wang, Wenjing Zhao, Jiawen Qu, Linan Gu, Jinlong Wang, Xunmei Liang, Fangzhou Ren and Jingjing Feng

Buildings 2026, 16(3), 680; https://doi.org/10.3390/buildings16030680 - 6 Feb 2026

Abstract

Calcium sulfoaluminate–calcium oxide expansive agents (HCSA) are commonly used in mass concrete to compensate for thermal shrinkage. However, the ettringite (AFt) formed by HCSA hydration decomposes when temperatures exceed 70 °C. This study examines the synergistic effects of curing temperature (20 °C to [...] Read more.

Calcium sulfoaluminate–calcium oxide expansive agents (HCSA) are commonly used in mass concrete to compensate for thermal shrinkage. However, the ettringite (AFt) formed by HCSA hydration decomposes when temperatures exceed 70 °C. This study examines the synergistic effects of curing temperature (20 °C to 80 °C), fly ash (FA) content (0%, 40%), and water–binder ratio (w/b, 0.3, 0.4, 0.5) on the expansion behaviour and microstructure of HCSA–cement systems. A critical temperature threshold was identified at 60 °C. Below this limit, elevated temperatures accelerate hydration and enhance expansion, with the restrained expansion ratio peaking at 9.2 × 10⁻⁴ mm/mm under 60 °C curing. Beyond 60 °C, expansion capacity significantly diminishes due to the thermal decomposition of AFt into monosulfoaluminate (AFm), as confirmed by XRD and SEM analysis. Calculations of expansive stress reveal a critical mismatch at temperatures ≥ 40 °C, where the expansive stress exceeds the early-age tensile strength, causing microstructural damage. Furthermore, subsequent cooling to standard curing conditions triggers the reformation of AFt from AFm, leading to Delayed Ettringite Formation (DEF), which poses potential risks for late-stage cracking. AFt morphology shifted from needle-like (2–5 μm) to prismatic (5–8 μm). The incorporation of FA suppressed early-stage expansion but improved expansion stability. above 40 °C, although excessive temperatures (>70 °C) led to pore coarsening and reduced mechanical strength. These findings provide a theoretical basis for optimizing the curing regimes of HCSA-admixed mass concrete to ensure structural integrity. Full article

(This article belongs to the Special Issue Research on Sustainable and High-Performance Cement-Based Materials)

32 pages, 1944 KB

Open AccessArticle

Demand-Side Energy Burden Inequality Between New and Old Urban Apartments from a Long-Term Perspective: Evidence from China’s Diverse Climate Zones

by Ziang Li, Haojie Li, Ying Bao and Jianfa Qiu

Buildings 2026, 16(3), 679; https://doi.org/10.3390/buildings16030679 - 6 Feb 2026

Abstract

Against the backdrop of rapid urbanization and climate change, energy burden inequity arises between existing and new residential buildings due to generational differences in building envelopes. This study develops a demand-side energy burden equity assessment framework based on energy simulations of typical existing [...] Read more.

Against the backdrop of rapid urbanization and climate change, energy burden inequity arises between existing and new residential buildings due to generational differences in building envelopes. This study develops a demand-side energy burden equity assessment framework based on energy simulations of typical existing and new apartments in representative cities across China’s five major climate zones. The framework integrates multi-climate conditions, long-term evolution under different Shared Socioeconomic Pathways, and adaptable retrofit implications. Results indicate that demand-side energy burden inequity is widespread but structurally heterogeneous across climate zones, with the largest disparity observed in heating-dominated regions (up to 95.69 kWh/m² in Harbin). Under future warming, three scaling pathways emerge: convergence in heating-dominated regions (up to −27%), divergence in cooling-dominated and mixed regions (up to +382%), and offsetting effects driven by heating–cooling structural shifts in cold regions (up to −5%). Retrofit analysis shows that combined envelope upgrades achieve substantial inequity reduction (88–152%), though with diminishing marginal returns, while single targeted measures already yield high benefits in cooling-dominated and mild regions (74% and 83%, respectively). The findings provide differentiated and forward-looking evidence to support equity-oriented interventions in urban residential retrofitting and policy design. Full article

(This article belongs to the Special Issue Evaluation and Design of Smart-Built Environments Based on Advanced Performance Simulation: From Building to Regional Scales)

20 pages, 7802 KB

Open AccessArticle

Thermal Environment and Adaptive Comfort in Traditional Lifen Dwellings During Summer: Field Measurements and Occupant Surveys in Wuhan, China

by Kangli Ren, Meng Yao, Yu He, Shuen Yao, Chiming Tang and Chi Zhang

Buildings 2026, 16(3), 678; https://doi.org/10.3390/buildings16030678 - 6 Feb 2026

Abstract

Under extreme summer heat and humidity, the indoor thermal environment and occupants’ thermal adaptability in Lifen dwellings, a high-density residential typology in Wuhan, China, remain insufficiently documented. This study compares summer indoor thermal conditions and thermal comfort between traditional and newly built Lifen [...] Read more.

Under extreme summer heat and humidity, the indoor thermal environment and occupants’ thermal adaptability in Lifen dwellings, a high-density residential typology in Wuhan, China, remain insufficiently documented. This study compares summer indoor thermal conditions and thermal comfort between traditional and newly built Lifen dwellings using combined field measurements and questionnaire surveys. Continuous monitoring was conducted in four representative dwellings from 16 to 21 July 2024, together with 192 valid questionnaires collected across the two Lifen communities. Results indicate clear differences in indoor thermal characteristics between the two dwelling types; old Lifen dwellings exhibited stronger perceived heat and more pronounced spatial thermal non-uniformity. Kitchens were identified as the most unfavorable spaces in dwellings. Regression analysis of thermal sensation reveals that residents in old dwellings had a higher neutral temperature than those in new dwellings (27.6 °C versus 26.0 °C) and demonstrated stronger overall thermal adaptability, with a relatively wider comfort range (0.8 °C). Combined evidence from field measurements and subjective voting suggests that long exposure, behavioral adjustment, and ventilation-driven cooling collectively enhance heat tolerance in old Lifen dwellings. These findings provide empirical support for thermal environment optimization and renovation strategies in naturally ventilated historic residential areas. Full article

(This article belongs to the Special Issue Healthy and Affordable Zero-Emission Buildings: A Challenge for the Near Future)

► Show Figures

Figure 1

21 pages, 4711 KB

Open AccessArticle

An Integrated Framework for Pavement Crack Segmentation and Severity Estimation

by Osama Alsharayah, Dmitry Manasreh and Munir D. Nazzal

Buildings 2026, 16(3), 677; https://doi.org/10.3390/buildings16030677 - 6 Feb 2026

Abstract

Pavement maintenance programs rely on timely and accurate crack assessment to preserve roadway quality and reduce long-term rehabilitation costs. Manual inspection remains the prevailing practice, yet it is slow, subjective, and exposes crews to safety risks. Automating crack detection under real-world roadway conditions [...] Read more.

Pavement maintenance programs rely on timely and accurate crack assessment to preserve roadway quality and reduce long-term rehabilitation costs. Manual inspection remains the prevailing practice, yet it is slow, subjective, and exposes crews to safety risks. Automating crack detection under real-world roadway conditions remains challenging due to inconsistent lighting, shadows, stains, and surface textures that obscure distress features. This study examines the applicability of an integrated, vehicle-mounted framework for automated pavement crack segmentation and width-based severity estimation under practical roadway operating conditions. Data were collected from a moving vehicle using a custom camera–GPS system operating under diverse conditions, capturing the variability encountered in practical surveys. The proposed approach employs a state-of-the-art segmentation model and a calibrated width estimation tool that converts pixel-level crack measurements into physical units using a position-dependent regression model. The key contribution of this work is a unified segmentation and severity evaluation pipeline supported by a novel pixel-to-inch calibration surface and validated using images acquired during normal driving operations and manual field crack measurements. By combining advanced computer vision techniques with practical field-oriented data collection, the proposed system provides a deployable solution for roadway crack assessment, enabling safer, faster, and more scalable network-level pavement monitoring. Full article

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

► Show Figures

Figure 1

17 pages, 2549 KB

Open AccessArticle

Validity of Design Standards in Shear Strength of CFRP Concrete Member Without Shear Reinforcement

by So Yeong Choi, Il Sun Kim and Eun Ik Yang

Buildings 2026, 16(3), 676; https://doi.org/10.3390/buildings16030676 - 6 Feb 2026

Abstract

The shear design of concrete members reinforced with Carbon Fiber Reinforced Polymer (CFRP) bars remains a key hurdle for engineers. This study experimentally investigates the shear behavior of normal-strength concrete members reinforced with CFRP bars without shear reinforcement subjected to monotonic loading. Specifically, [...] Read more.

The shear design of concrete members reinforced with Carbon Fiber Reinforced Polymer (CFRP) bars remains a key hurdle for engineers. This study experimentally investigates the shear behavior of normal-strength concrete members reinforced with CFRP bars without shear reinforcement subjected to monotonic loading. Specifically, this research investigates the effect of anchorage length on shear-dominated behavior, aiming to provide a novel assessment of the interaction between shear and anchorage design—two aspects that have traditionally been treated in isolation in existing studies. The experimental results revealed that all test members, regardless of reinforcement type or anchorage length, exhibited a shear strength ranging from 1.1 to 5.63 times the code-predicted values, confirming the conservatism of current design standards. This pronounced difference in the shear strength of reinforced members is attributed to (1) the unexpectedly significant contribution of dowel action because of the high tensile strength and over-reinforcement ratio, and (2) the inherent conservatism in current code equations for shear capacity. Unlike prior studies that noted conservative shear prediction, this research demonstrated that anchorage length requirements, which are typically linked to flexural design, can be significantly relaxed in shear-dominated members with safety secured. This research highlights the need to refine shear prediction models for CFRP members by incorporating parameters that account for the reinforcement ratio and the unique contribution of dowel action. Furthermore, a revision of anchorage length design standards is justified to develop a more rational and economical design for shear-dominated members. Full article

(This article belongs to the Special Issue Research on Sustainable Materials in Building and Construction)

► Show Figures

Figure 1

Journal Description

Buildings

Latest Articles

Journal Menu

Journal Browser

Highly Accessed Articles

Latest Books

E-Mail Alert

News

Topics

Conferences

Special Issues

Topical Collections

Further Information

Guidelines

MDPI Initiatives

Follow MDPI