Search Results (671)

The aim of the study is to develop a qualitative–quantitative assessment method to determine the resilience factor of buildings. The methodological structure is holistic, integrating different levels of indicators by cross-referencing the parameters of the Italian Minimum Environmental Criteria (CAM) technical specifications and the parameters of the building life cycle phases (LCA). The methodology involved the development of two models (CAM/LCA), which were applied to two case studies for validation: a first case study (multifunctional building) with a steel construction system, mainly dry-assembled; and a second case study (laboratory building) with a prefabricated concrete construction system. The results showed that the most resilient building is the multipurpose building, i.e., the one with a steel structure. The results obtained are consistent with scientific research in the field, highlighting the greater sustainability of the steel construction system compared to the reinforced concrete system. The models developed can be used both in the pre-operam and post-operam phases. In the first case, the assignment of dependencies to indicators defines the design guidelines, i.e., it directs professionals to adopt strategies that can have the maximum impact on achieving the initial objective (maximum resilience factor). In the post-operational phase, on the other hand, the models allow the resilience factor to be assessed at its current state, highlighting any particular critical issues and guiding operators toward possible improvement strategies. Full article

This study investigates the influence of adhesive type on the bond performance between CFRP plates and steel interfaces through static tensile double-shear tests. Three types of adhesives (Araldite 420A/B, 2015-1, Sikadur-30CN) were tested under four bond lengths. The results indicate that adhesive strength significantly affects failure characteristics, with distinct material performance differences observed. Bond length influences the stress distribution, enhancing dispersion while potentially altering damage progression. High-performance adhesives exhibit superior shear resistance and fracture energy due to improved viscous properties, whereas moderately plastic adhesives achieve adaptive deformation and durable bonding by enhancing the flow and substrate contact. These findings provide a theoretical basis for material selection in CFRP-strengthened steel structures and offer actionable guidance for structural repair engineering applications. Full article

Prefabricated steel structures have been increasingly adopted in modern construction due to their high efficiency, sustainability, and industrialized production. However, their construction quality and efficiency are often compromised by accumulated geometric deviations during fabrication, transportation, assembly, and welding, while traditional construction control and welding processes remain highly dependent on manual measurements and empirical operations. To address these challenges, this study proposes a digital construction framework for prefabricated steel structures, integrating high-precision three-dimensional (3D) laser scanning, Building Information Modeling (BIM), and intelligent welding technologies. First, high-precision 3D laser scanning is employed to capture the as-built geometric information of prefabricated steel components, generating dense point cloud data for construction-stage deviation detection and quantitative comparison with BIM-based design models. Based on deviation analysis, a digital construction control strategy is established to support real-time feedback, error compensation, and assembly adjustment. An engineering case study involving a complex prefabricated steel structure is conducted to validate the proposed framework. The results demonstrate that the integrated digital construction and intelligent welding approach significantly improves assembly accuracy, weld positioning precision, and construction efficiency, while reducing manual intervention and error accumulation. Overall, this study contributes to the body of knowledge by proposing a unified closed-loop digital construction paradigm that integrates geometric perception, deviation-driven decision-making, and intelligent welding execution, thereby bridging the gap between construction control and robotic fabrication in prefabricated steel structures. Full article

With the vigorous promotion of the modernization of China’s construction industry, the proportion of prefabricated buildings in new construction projects has increased steadily. Grouted sleeve connection is a mainstream joining method for prefabricated components, and the performance of grouting materials is crucial to connection reliability. In this study, a modified polyurethane composite (MPC) was developed as a novel sleeve grouting material, and seven grouted splice specimens with different steel bar strength grades and anchorage lengths were fabricated for uniaxial tensile tests. The mechanical properties of MPC and the connection performance of specimens were systematically investigated, and the effects of steel bar strength grade and anchorage length on ultimate load, average bond strength, and strain characteristics were quantitatively analyzed. The results show that MPC has excellent fluidity, and its mechanical strengths meet the specified requirements. Increasing steel bar strength grade and anchorage length significantly improves ultimate load: at a 6d anchorage length, the ultimate load of the S600 series (HRB600E) is 44.85% higher than that of the S400 series (HRB400E); extending the S400 series’ anchorage length from 4d to 8d increases ultimate load by 50.61%. Average bond strength decreases with increasing anchorage length (S400-MPC-8d is 24.70% lower than S400-MPC-4d) but increases with higher steel bar strength grade (S600-MPC-6d is 32.37% higher than S400-MPC-6d). The sleeve remains elastic during the test, ensuring safety. Prediction formulas for average bond strength under slip failure were established, with good agreement between predicted and experimental results. For both HRB400E and HTRB600E steel bars, considering safety and installation errors, a critical anchorage length of 8d is recommended for engineering design. Full article

Urban rooftop photovoltaic systems represent a substantial yet still underutilized renewable energy resource, particularly in high-density residential environments. Accurate large-scale assessment of rooftop solar potential, however, remains challenging due to the complex geometry of urban morphology and the limited availability of high-resolution geospatial data. This study presents a large-scale methodological framework for estimating the theoretical photovoltaic potential of urban rooftop spaces using Unmanned Aerial System (UAS)-based digital photogrammetry and GIS-based spatial analysis. The approach integrates centimeter-resolution Digital Surface Models (DSMs) and orthophotos derived from fixed-wing UAS surveys with detailed rooftop vectorization and solar radiation modeling implemented in a GIS environment. The methodology accounts for rooftop geometry, surface orientation, slope, shading effects, and rooftop-mounted obstacles. The methodology consists of data collection of high-resolution RGB imagery suitable for detailed three-dimensional reconstruction. The images are captured with a UAS equipped with a S.O.D.A. 3D photogrammetric camera, creating a dense, georeferenced three-dimensional point cloud based on UAS imagery. Based on the point cloud, a high-resolution Digital Surface Model (DSM) was produced. Rooftop boundaries and rooftop-mounted structures were digitized on the basis of an orthophoto created from UAS imagery. The analysis workflow consists of solar modeling using ArcGIS Pro, including calculating the solar radiation. The next methodological step is to filter low radiation rooftops, steep slopes, and northern-oriented rooftops. Finally, we calculate the potential electricity production. The framework was applied to high-density residential districts in Sofia, Bulgaria, dominated by prefabricated panel buildings with predominantly flat rooftops. Drone applications in such studies are typically restricted to modeling individual roofs, which severely limits their scalability for district-wide evaluations. To overcome this, the study employs a specialized fixed-wing UAS uniquely certified for legal operations over densely populated urban environments. This platform rapidly maps large territories, ensuring consistent lighting and shading conditions that significantly enhance the accuracy of subsequent rooftop digitization. Furthermore, the resulting centimeter-level precision enables the exact vectorization of micro-rooftop obstacles. Capturing these intricate details is a critical innovation that effectively prevents the overestimation of solar energy potential commonly observed in conventional large-scale models. Solar radiation was modeled at the pixel level for a full annual cycle and filtered using photovoltaic suitability criteria, including minimum annual radiation thresholds, slope, and aspect constraints. Theoretical electricity production was subsequently estimated using zonal statistics and system performance parameters representative of contemporary photovoltaic installations. The results indicate a total theoretical annual electricity potential of approximately 76.7 GWh for the analyzed rooftop spaces, with an average production of about 34 MWh per rooftop and pronounced spatial variability driven by rooftop geometry and exposure conditions. The findings demonstrate the significant renewable energy potential embedded in existing urban rooftop infrastructure and highlight the applicability of UAS-based photogrammetry for high-resolution, large-area solar potential assessments. The proposed framework provides actionable information for urban energy planning, municipal solar cadaster development, and the strategic integration of photovoltaic systems into dense urban environments, particularly in regions lacking open-access high-resolution geospatial datasets. Full article

Gypsum-based materials are widely used in construction but suffer from poor water resistance and durability, limiting their application in moisture-prone environments. While fiber-reinforced modified gypsum (FRMG) improves mechanical performance, the lack of systematic research on waterproofing strategies and their influence on both durability and strength remains a key challenge. This study investigated three waterproofing methods: surface coating with paraffin emulsion, internal incorporation of paraffin emulsion, and internal incorporation of vinyl acetate ethylene (VAE) emulsion. The workability, water absorption, mechanical properties, contact angle, and microstructure of the FRMG matrix were analyzed. The results showed that surface coating provided only short-term waterproofing. Internal incorporation of paraffin emulsion reduced water absorption but weakened mechanical performance. In contrast, VAE emulsion formed continuous polymer films that filled pores, significantly reducing water absorption while improving flexural and compressive strength, with optimal performance observed at a 6% dosage. In addition, increasing emulsion content enhanced hydrophobicity. These results indicate that VAE-based internal modification is an effective approach to improving the durability and performance of gypsum-based materials, providing guidance for their application in interior wall systems and prefabricated building components. Full article

In response to escalating global environmental challenges, mitigating carbon emissions in the construction sector has emerged as a critical strategy for addressing climate change. As reported by the United Nations Environment Programme (UNEP) and the International Energy Agency (IEA), the construction industry remains a major contributor to global greenhouse gas emissions. This study investigates the influencing factors and optimization pathways for embodied carbon emissions during the materialization phase of prefabricated buildings. Through longitudinal field research at a large-scale precast component factory in western China, key carbon emission factors were identified using Min–Max normalization and Principal-Components Analysis (PCA). A cloud entropy–based evaluation model was further developed to quantify the emission weights of 32 factors. The results reveal the existence of ‘leveraging effects’ among emission factors, wherein certain low-weight factors exert disproportionate influence on systemic carbon reduction because of their cascading impacts on other variables. Prioritizing factors with greater leveraging potential is imperative for the formulation of effective emission reduction policies. This study leverages NK model simulations (10,000 iterations), to predict the reduction potential of each factor and identifies four indicators with the most significant leveraging effects. Strategic recommendations are proposed that emphasize a synergistic approach that integrates direct emission control and indirect cascading optimization. These findings provide actionable insights for achieving systemic carbon reduction in prefabricated building systems. Full article

The operation and maintenance (O&M) management of prefabricated buildings often struggles with fragmented knowledge and low reusability, relying predominantly on expert experience. While large language models (LLMs) offer a potential solution, their inherent hallucination issues significantly hinder practical application. To address these issues, this study proposes a knowledge base-augmented OM-GPT for prefabricated buildings O&M, built on a hybrid architecture that combines domain-specific fine-tuning with graph-based retrieval-augmented generation (GraphRAG). Specifically, it first fine-tuned the LLM Qwen2.5 using specialized O&M data to enhance its understanding of O&M tasks. It then constructed a multi-relational knowledge graph within a GraphRAG framework to effectively mitigate model hallucinations. Experimental results demonstrate that the Fine-Tuned Model achieved excellent Recall-Oriented Understudy for Gisting Evaluation (ROUGE) scores, validating the success of domain adaptation. In a five-dimensional evaluation, knowledge base-augmented OM-GPT significantly outperformed both GPT-4 and DeepSeek. Furthermore, two-way ANOVA tests confirmed the model’s advantages generalize across all five evaluation dimensions. Full article

Adaptive reuse has emerged to become a tool for implementing the understanding of sustainability in the domain of architectural conservation, as it encourages the continued usage of old buildings as means of reducing environmental impact, as well as preserving socio-cultural capital while generating economic income. However, in its practice, the decisions regarding granting meanings, interpretation, and preserving memories within adaptation processes are dominated by expert-driven approaches that inadequately incorporate stakeholder values or intangible heritage dimensions. To this end, this study aims to contribute to the current debate by adopting a participatory co-evaluation framework that integrates both authenticity perspectives and sustainability dimensions using Multi-Criteria Decision Analysis (MCDA) for evaluating adaptive reuse alternatives for an abandoned prefabricated wooden heritage building. Stakeholder priorities were drawn through a workshop and transformed into normalized weights using the Simos technique. Four design alternative typologies—namely, Continuity, Cultivation, Differential, and Optimization—were assessed and compared against 20 performance indicators across heritage, social, ecological, and economic criteria using the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). Indicator-level analyses and sensitivity tests (±10% and ±20% weight variations) were applied to confirm the robustness of rankings. The results from the best-performing alternative demonstrated the trade-offs between heritage authenticity and sustainability objectives, as well as demonstrating how combining participatory methods with quantitative evaluation can support evidence-based decision-making for adaptive reuse. The applied integrated framework helps bridge the gap between heritage theory and practice by combining authenticity, participation, and sustainability in one analytical approach, supporting evidence-based decisions for adaptive reuse. Full article

Prefabricated reinforced concrete shear wall structures have attracted significant attention due to their advantages in industrialized construction and sustainability. However, the structural performance of prefabricated shear wall systems still requires further investigation to ensure reliable seismic behavior under earthquake loading. In this study, a fully prefabricated shear wall system incorporating keyway interlocking joints and concentrated reinforcement connections is proposed, and its nonlinear seismic behavior is systematically investigated through finite element modeling, parametric analysis, nonlinear time history analysis, and incremental dynamic analysis. The finite element models were validated against available experimental results and reproduced the hysteretic response, stiffness degradation, and load-carrying capacity with good agreement. The relative errors in peak load were within 5%, indicating the reliability of the adopted modeling approach. Parametric analyses indicate that axial compression ratio, concrete strength, and wall thickness significantly affect structural performance, while prefabricated walls exhibit slightly lower stiffness and strength than cast-in-place walls, with mean reduction factors of 0.88 and 0.91. An eight-story prefabricated shear wall building subjected to multiple scaled ground motions exhibits stable flexure-dominated deformation without joint sliding or soft-story mechanisms. Peak roof displacements reached 19.71 mm and 32.85 mm in the X and Y directions, with maximum interstory drift ratios of 1/892 and 1/724. These values are significantly smaller than the commonly adopted collapse drift limit of 1/120 specified in seismic design guidelines, indicating a relatively large deformation safety margin under the ground motions considered. Probabilistic seismic demand models were established based on both PGA and Sa(T₁, 5%) intensity measures, showing strong correlations with the maximum interstory drift ratio. Fragility analysis demonstrates a high probability of remaining in intact or slight damage states under frequent and design-level earthquakes and a low collapse probability under rare earthquakes. These findings provide valuable insights for the design of next-generation prefabricated shear wall systems with mechanical interlocking joints and concentrated reinforcement connections. Full article

The steel frame-shear wall composite system has excellent lateral resistance performance in prefabricated steel structure buildings. However, the traditional steel plate concrete shear wall is prone to early buckling of the steel plate and concentrated interface damage under cyclic loading, which limits its energy dissipation capacity. This study presents a steel plate-enhanced reinforced concrete shear wall (SPRCSW) with an internal corrugated steel plate and double-layer steel mesh working together and conducts a selection study based on finite element analysis. Under the same design conditions, the peak bearing capacity in the positive and reverse directions of the SPRCSW is increased by approximately 55.4% and 46.9%, respectively, compared to the ordinary reinforced concrete shear wall, with a ductility coefficient reaching 6.08. The stiffness decline is mild, and the hysteretic curve is complete. Then, this paper forms an SR-SPRCSW composite structural system by combining the new shear wall with a steel frame using semi-rigid joints. Through the comparison of the finite element analysis and low-cycle reverse loading test results of the SR-SPRCSW structure, it is verified that the overall structural system shows good agreement in hysteretic response, skeleton curve characteristics, and failure mode under both research methods, with the peak shear bearing capacity error of less than 1% and the overall bearing capacity deviation controlled within 8%. On this basis, the key parameters of the semi-rigid joints in the SR-SPRCSW structure are analyzed. The results show that the strengthening of the “top and bottom + double web” angle steel joint can raise the peak bearing capacity of the SR-SPRCSW structure by approximately 26.1% and the yield displacement by approximately 29.5%; increasing the strength grade and diameter of high-strength bolts can heighten the initial stiffness and bearing capacity of the overall structure, but ductility slightly decreases; the thickness of the angle steel has a significant impact on the stiffness and deformation capacity of the structure, and a recommended range of values with better comprehensive performance is provided. The findings offer valuable insights for designing seismic-resistant semi-rigid steel frames with steel plate reinforced concrete shear walls and optimizing their parameters. Full article

The built environment in the EU accounts for 40% of the total energy consumption and 36% of the total greenhouse gas emissions. To address the inefficiency of existing buildings, renovation could reduce their total energy consumption by 5–6% and lower carbon dioxide emissions by approximately 5%. A retrofit solution for existing buildings involves the use of lightweight prefabricated systems, some of which include integrated HVAC components that are able to enhance their functionality. Indeed, such prefabricated facade elements with integrated HVAC systems can represent a minimally invasive method for reducing the energy consumption of an existing building. To assess the potential of this approach, a full-scale mock-up of a prefabricated timber facade with integrated HVAC system was tested at the Facade System Interactions Lab (FSIL) of Eurac Research, Bolzano. The experimental data were used to develop a calibrated and validated 3D finite element model in COMSOL Multiphysics. The validated model was used to evaluate the facade’s thermal performance under standard heating conditions through a proposed equivalent thermal transmittance indicator (U_eq). Results show that the active facade achieves 0.07 W m⁻² K⁻¹, compared to 0.21 W m⁻² K⁻¹ for the passive facade with identical materials but without active components. Full article

We present a modular building block strategy for synthesizing phosphonated polyaromatic systems as an alternative to the conventional late-stage phosphonation of prefabricated aromatic scaffolds, which often requires harsh conditions and has limited tolerance for functional groups. A monophosphonated biphenyl building block was obtained via nickel-catalyzed phosphonation of dibromobiphenyl at 170 °C for three hours. This synthesis is more economical and milder than typical high-temperature palladium systems. In parallel, a borated pyrene derivative was prepared by Suzuki–Miyaura borylation. The final palladium-catalyzed Suzuki cross-coupling reaction produced the target compound, octaethyl(pyrene-tetrakis(biphenyl))tetrakis(phosphonate), Et₈-PyTPPE. Single-crystal X-ray diffraction reveals a centrosymmetric molecule that crystallizes in the triclinic space group P–1, with the inversion center located at the central C–C bond of the pyrene core. The pyrene unit is essentially planar, while the biphenylphosphonate arms are highly twisted relative to the core and to each other. The crystal packing is dominated by weak intermolecular interactions, and no significant π–π stacking is observed. Hirshfeld surface analysis shows that H···H (60.5%) and C···H (22.5%) contacts predominate, while O···H interactions (14.4%) with phosphoryl oxygen atoms represent the most relevant directed contacts. From photophysical investigations, Et₈-PyTPPE exhibits blue fluorescence (λ_em. = 452 nm) in solution and aggregation-induced red-shifted emission with nanosecond lifetimes in the solid state, confirming purely fluorescent behavior. Full article

Turkey, located on one of the world’s most active fault lines, frequently experiences major earthquakes. The 2023 Kahramanmaraş earthquakes (Mw 7.6 and 7.7) caused significant destruction and housing shortages. Post-disaster shelters are often provided using containers, which require flat and solid ground. This typically involves pouring concrete foundations, but high demand for materials and labor hinders rapid installation. This study investigates screw piles as an alternative foundation system for container settlements. Screw piles can eliminate the need for concrete, offering a faster, cost-effective, and environmentally friendly solution. Finite element analyses using Abaqus were conducted to assess the structural behavior of container foundations with screw piles under real earthquake records. Additionally, a decision-making analysis based on the Analytic Hierarchy Process compares screw piles and concrete foundations in terms of cost, time, sustainability, and safety. Results show that screw piles reduce structural responses and are a more feasible post-disaster foundation solution. Full article