Search Results (14,058)

The sustainability of bridge infrastructure is becoming increasingly important due to rising environmental, economic, and social demands. However, most current assessment models remain fragmented, often overlooking the social pillar, underutilizing risk integration across the lifecycle, and failing to fully leverage digital tools such as Building Information Modeling (BIM) and Life Cycle Sustainability Assessment (LCSA), resulting in incomplete sustainability evaluations. This study addresses these limitations by introducing a practical and adaptable model that integrates BIM, LCSA, and expert-driven risk prioritization. Five Hungarian bridge projects were modeled using Tekla Structures and analyzed in OpenLCA to quantify environmental, economic, and social performance. A custom Sustainability Level Change (SLC) algorithm was developed to compare baseline scenarios (equal weighting) with risk-informed alternatives, simulating the impact of targeted improvements. The results demonstrated that prioritizing high-risk sustainability indicators leads to measurable lifecycle gains, typically achieving SLC improvements between +2% and +6%. In critical cases, targeted enhancement scenarios, applying 5% and 10% improvements to top-ranked, high-risk indicators, pushed gains up to +12%. Even underperforming bridges exhibited performance enhancements when targeted actions were applied. The proposed framework is robust, standards-aligned, and methodologically adaptable to various bridge types and lifecycle phases through its data-driven architecture. It empowers infrastructure stakeholders to make more informed, risk-aware, and data-driven sustainability decisions, advancing best practices in bridge planning and evaluation. Compared to earlier tools that overlook risk dynamics and offer limited lifecycle coverage, this framework provides a more comprehensive, actionable, and multi-dimensional approach. Full article

The dramatic increase in global construction and demolition waste (CDW) is a considerable environmental challenge, but recycled building materials face serious marketing bottlenecks. Although existing studies have focused on the technological path and policy regulation of CDW management, they have not yet considered the impact of sales effort level under the dual-channel sales model. Considering the coexistence of price competition and bidirectional free-riding behavior, this paper constructs a Stackelberg game model, which includes a construction waste remanufacturer with both online and offline sales channels and a building materials retailer, to reveal the pricing decision-making mechanism under bidirectional free-riding behavior. The results of the study show that (1) in the decentralized decision-making model, offline free-riding has a negative effect on the online channel, and when the effort cost coefficient is high, it increases the retail price of recycled cement in the offline channel; at the same time, under high cross-price sensitivity, both the manufacturer and the retailer are negatively affected by online free-riding behaviors; (2) in contrast to decentralized decision-making, centralized decision-making motivates the supply chain as a whole to significantly increase sales effort investment and develop a better pricing strategy under the condition of satisfying the threshold cross-price sensitivity, which ultimately improves the overall efficiency of the supply chain. The findings provide an important theoretical basis and management insights for the coordination of dual-channel supply chains, the governance of free-riding behavior, and the promotion of recycled building materials in the recycling economy. Full article

The accurate detection of embedded parts and truss rebars in prefabricated concrete composite slabs before casting is essential in ensuring structural safety and reliability. However, traditional inspection methods are time-consuming and lack real-time monitoring capabilities, limiting their suitability for modern prefabrication workflows. To address these challenges, this study proposes MBAV, a lightweight object detection model for the quality inspection of prefabricated concrete composite slabs. A dedicated dataset was built to compensate for the absence of public data and to provide sufficient training samples. The proposed model integrates positional encoding into a lightweight architecture to enhance its ability to capture multiscale features in complex environments. Ablation and comparative experiments on the self-constructed dataset show that MBAV achieves an mAP₅₀ of 91% with a model size of only 5.7 MB—8% smaller than comparable models. These results demonstrate that MBAV is accurate and efficient, with its lightweight design showing strong potential for real-time quality inspection in prefabricated concrete production. Full article

The behavior response of an existing shield tunnel to under-cross tunneling is fundamentally governed by the tunnel–soil interaction. In this study, the existing tunnel is simplified as a single-variable Timoshenko beam to address the shear locking issue of the conventional Timoshenko beam. An elastic continuum solution, which can be degenerated into the Winkler–Timoshenko model, is established by considering the tunnel–soil interaction to evaluate the existing tunnel’s response to underlying tunneling. Meanwhile, greenfield settlement is described using a modified Gaussian function to fit practical engineering cases. The joint opening and segmental dislocation are also quantified. The applicability of the proposed method is validated by two reported engineering cases, where measured greenfield settlements are used to verify the modified Peck formula. Key parameters, including the ground loss rate, intersection angle, tunnel–soil stiffness factor, and vertical clearance, are discussed. The results show that the proposed method can provide references for predicting the potential diseases of existing tunnels affected by new tunnel excavation. Full article

The Sixth Assessment Report of the IPCC highlights that global surface temperatures have risen by 1.1 °C above pre-industrial levels, with a marked increase in the frequency and intensity of extreme heat events in hot–humid regions. Buildings in these areas urgently require passive design strategies to enhance climate adaptability. Employing Zhupu Ancient Village in Chaoshan region in China as an example, this study analyzes and evaluates the wind-driven ventilation archetype and buoyancy-driven ventilation archetype of the village through integrated meteorological data analysis (ECMWF) and computational fluid dynamics (CFD) simulations. The results indicate that the traditional climate-adaptive archetype facilitates wind speeds exceeding 0.5 m/s in over 80% of outdoor areas, achieving unobstructed airflow and a discernible stack ventilation effect. Through archetype translation, the visitor center design incorporates open alleyway systems and water-evaporative cooling strategies, demonstrating that over 80% of outdoor areas attain wind speeds of 0.5 m/s during summer, thereby achieving enhanced ventilation performance. The research provides a climate-response-archetype translation-performance validation framework and practical case studies for climate-adaptive design of public buildings in hot–humid regions. Full article

Tropical regions experience intense and highly variable solar radiation, often resulting in excessive indoor illuminance, uneven daylight distribution, and visual discomfort in high-rise residential buildings. This study investigates the daylighting performance of various external horizontal slat configurations as a shading strategy for east- and south-facing rooms in a typical high-rise apartment under both intermediate sky with sun and overcast sky conditions. Using IESVE simulations, ten shading device (SD) configurations (SD 1–SD 10) were evaluated for their impact on daylight illuminance and distribution uniformity. Results show that high-rise apartment room with a commonly used overhang provided poor daylighting quality, with excessive illuminance and low distribution uniformity. SD 10 and SD 9 achieved the best performance at 09:00 and 12:00, respectively, for east-facing rooms across design days, while SD 10 was optimal for south-facing rooms on both 21 March and 22 December. Under overcast sky conditions, SD 9 demonstrated superior performance. This study proposes a novel adaptive external shading device featuring adjustable horizontal slats that can be reconfigured throughout the day to respond to changing solar positions and sky conditions. This approach overcomes the limitations of fixed shading systems by adapting to dynamic tropical sky conditions, offering a practical solution for enhancing daylight quality in tropical high-rise apartments. The findings provide design guidance for the development of energy-efficient shading, climate-responsive shading systems tailored to tropical environments. Full article

This study identifies and refines the dimensions of cultural inheritance and innovative practices in industrial heritage-themed districts and develops a corresponding questionnaire scale. Based on the ABC model of attitudes, a conceptual model is constructed to examine the impact of cultural inheritance and innovation on tourist behavior, which is then empirically tested using Structural Equation Modeling (SEM). The findings reveal that the influence and mechanism of cultural inheritance and innovative practices on tourist behavior follow a continuous process in the sequence of cognition–affect–behavior tendency. All four dimensions of cultural inheritance and innovation exert a significant positive effect on tourist loyalty. Moreover, the affective component serves as a mediating factor within the chain reaction. This study constructs a new theoretical framework to explore how cultural inheritance and innovation jointly influence the formation of tourist loyalty and the underlying mechanisms, enriching the theoretical system of industrial heritage tourism and cultural management. It also provides practical theoretical support for district planning, design, and management. Full article

This study investigates the impact of incorporating construction and demolition waste (CDW) aggregates and Alfa natural fibers on the performance characteristics of asphalt mixtures, with a focus on mixing temperature. Several formulations were developed and evaluated through multiphysics property measurements, including density, ultrasonic pulse velocity, rutting resistance, thermal conductivity, and spectral reflectance. The results indicate that Alfa fibers enhance thermal resistance and spectral reflectance. Notably, incorporating 1% Alfa fiber and 20% CDW while reducing the mixing temperature to 150 °C significantly improves rutting resistance. These combined effects result in an optimized formulation that is more resistant to thermal stress during service, thereby enhancing its performance at elevated temperatures. These findings highlight the potential of integrating CDW and natural fibers into asphalt mixtures to develop environmentally friendly and thermally resilient materials, particularly for warming climate regions. Full article

This study investigates the long-term flexural performance of prestressed concrete double tees under sustained loading. Six full-scale specimens were subjected to a comprehensive experimental program, including a 320-day storage period following prestress release, a short-term flexural test, and a 990-day sustained loading phase. Mid-span deflections were measured using a string-line method, while the effective prestress in tendons was continuously monitored with fiber Bragg grating (FBG) sensors. Results showed a pronounced increase in camber during the storage phase, with long-term camber reaching approximately three times the initial value. Under short-term loading, the slabs exhibited a clear bilinear moment–deflection behavior. During sustained loading, most of the long-term deflection developed in the early stages, and an inverse relationship between load level and deflection growth was observed. Additionally, data from 20 short-term tests were compiled, and a bilinear stiffness model was proposed to estimate flexural stiffness in the cracked state. These findings contribute to a deeper understanding of long-term deformation in prestressed concrete double tees and provide reference data for serviceability evaluation and design refinement. Full article

In the paper, using the three-statement financial modelling methodology as applied to a representative development project, we aim to analyse, ex ante, the industry-level impact of transition to mandatory escrow schemes in residential and mixed-use construction in Tashkent city (due to be implemented in Uzbekistan from 2026). Modelling single-milestone escrow plans against the current steep-discount advance-based system of off-plans as a baseline, the model accounts for salient institutional features of the Tashkent city development market, including land auctioning, full-cycle Value-added tax (VAT) accounting, and Tax loss carryforward provisions. It also incorporates a framework for demand-driven residual valuations for the development land element. Our findings indicate practically unchanged cashflow profitability of developers on the market in question. Around 30% p.a. in nominal Free-cashflow-to-equity based IRRs expressed in the national currency, provided that the transition to the greater use of leverage in funding unfolds as expected. The disappearance of steep off-plan discounts while the transition to escrows unfolds will be countervailed by the reliance on costly loans from escrow banks. Absent the greater use of leverage, the IRR (FCFE) profitability of the developers is expected to decline by some 5%. For the apartment buyers, this is effectively equivalent to increasing property transaction prices on the primary market in line with their headline asking amounts. Thus-generated economic surplus will be partially captured by the developers and partially passed through to escrow banks, increasing their gross profits by up to $50M, p.a. due to their new role in financing Tashkent city residential developments that are still largely equity-driven. Apart from this effect, we find only a moderate financial leverage influence on developers’ profitability due to the high-interest-rate environment prevailing in Uzbekistan. We also find a demand-driven pressure on land auction prices suggested by increasingly back-loaded alterations in project cashflow profiles. This study also purports to make a material contribution to the evolving body of literature on financial modelling of apartment and mixed-use property developments by offering a flexible three-statement modelling framework with innovative endogenised equity management features. Full article

This study addresses the challenge of optimizing envelope retrofit strategies for aged residential buildings across China’s five distinct climate zones. A simulation-based frame work is proposed, applying a standardized Taguchi L27 experimental design to ensure direct comparability across climates. Analysis of variance (ANOVA) and effect size (partial eta squared, η²) are used to identify and quantitatively rank the sensitivity of each retrofit parameter, while interaction analysis reveals the independence or synergy between measures. Technical results are linked with discounted payback period (DPP) analysis to evaluate economic feasibility. The findings show that insulation thickness is most influential in cold climates (η² > 0.95), whereas glazing system upgrades are dominant in warmer regions (η² > 0.97), with parameter interactions generally insignificant. The resulting climate-responsive retrofit priority matrix offers practical guidance for region-specific design and investment decisions. This scalable and replicable method enables policymakers and practitioners to tailor low-carbon, cost-effective retrofit solutions to diverse building and climate contexts, bridging the gap between technical performance and financial viability. Full article

Understanding concrete creep aging is essential for ensuring structural safety and long-term durability, while the lack of robust numerical models limits the ability to thoroughly investigate and accurately predict time-dependent deformation and cracking behaviors. This study proposes a numerical framework integrating a discrete model and the microprestress solidification (MPS) theory to describe the aging creep and quasi-static performance of concrete at early-age and beyond. Hydration kinetics were formulated into constitutive equations to consider the time-dependent evolution of elastic modulus, strength, and fracture properties. Derived from the MPS theory, a unified creep model is developed within the equivalent rheological framework based on strain additivity. This formulation accounts for both visco-elastic and purely viscous creep phases while coupling environmental humidity effects with aging through the hydration degree. The proposed model is validated against experimental datasets encompassing diverse curing conditions, loading histories, and environmental exposures. The simulation results demonstrate that extended curing age enhances concrete strength (compression and fracture), while increased curing temperature has minimal impact due to the competing effects of microstructural refinement and thermal microcracking; both drying-induced transient creep and thermally induced microcracking contribute to increased creep deformation, driven by changes in microprestress resulting from variations in the chemical potential of nanopore water. The proposed numerical model can provide an effective tool to design and predict the long-term performance of concrete under various environmental conditions. Full article

This study develops a comprehensive evaluation framework for urban street alfresco spaces by integrating the Analytic Hierarchy Process (AHP) and Entropy Weight Method. Daxue Road in Shanghai is selected as a representative case to analyze key factors influencing urban street alfresco spaces, which refer to commercially utilized outdoor extensions of building facades along streets, typically in the form of semi-open, publicly accessible areas used for dining, vending, seating, or temporary retail activities. These spaces are typically operated by adjacent businesses or regulated by local policies, and they integrate pedestrian circulation, commercial vibrancy, and spatial adaptability. They serve as critical urban interfaces that foster street-level vibrancy, social interaction, and public life. The evaluation system covers five dimensions: Cognizability, Accessibility, Participation, Emotional Design, and Spatial Diversity. The methodological innovation lies in integrating subjective weights derived from AHP with objective weights obtained through entropy calculations, which enhances the scientific rigor and neutrality of the evaluation. The results show that traffic safety (weight = 0.0644) and locational attributes of streets (weight = 0.0574) are the most influential factors affecting user perception. Compared to previous studies that often prioritize visual aesthetics or commercial density, this study underscores the significance of traffic-related factors, indicating a shift in user preferences in high-density urban environments. The findings provide practical guidance for urban design and policy to improve the quality, safety, and vitality of street-level public spaces in high-density cities. This research contributes to the theoretical foundation for sustainable and human-oriented street regeneration. Full article

This study aims to critically assesses the application and limitations of Universal Design (UD) and Inclusive Design (ID) in Bangkok’s public parks and proposes a context-sensitive framework to enhance urban inclusivity. While UD has contributed significantly to improving physical accessibility—through standardized features such as ramps, tactile paving, and clear circulation paths—it often fails to address emotional comfort, cultural representation, and participatory engagement. In contrast, ID emphasizes co-creation, contextual adaptability, and symbolic inclusion, offering a more holistic and equity-driven approach. Using a five-dimensional comparative framework—philosophy, function, spatial logic, user engagement, and evaluation—this research analyzes three major public parks: Benjakitti Forest Park, Chatuchak (Railway) Park, and Chulalongkorn Centenary Park. Each site was evaluated through narrative critique, dimension scoring, and radar diagram visualizations. The findings reveal that while all three parks exhibit strong UD characteristics, they lack alignment with ID principles, particularly in the areas of community engagement and emotional resonance. These typologies highlight a broader trend in Thai public space planning, wherein accessibility is interpreted narrowly as compliance rather than inclusion. The study concludes by proposing policy and design recommendations for embedding ID into future park development, positioning ID not only as a design approach but as a paradigm for spatial justice, belonging, and cultural sustainability. Full article

High outdoor PM_2.5 levels in Chinese cities pose significant challenges to maintaining healthy indoor air quality in residential buildings, where mechanical ventilation systems are increasingly adopted for pollution control. In this paper, to control the indoor PM_2.5 concentration, a mass balance equation for the non-uniform mixing model has been established to calculate the filter efficiency. This study aims to optimize PM_2.5 pollution control in residential buildings through mechanical ventilation systems by evaluating the synergistic effects of filter efficiency and ventilation air flow rates under high outdoor PM_2.5 conditions. Field measurements and numerical calculations were conducted to monitor indoor and outdoor PM_2.5 concentrations. Results showed that, When outdoor PM_2.5 concentrations remain below 100 μg/m³, an air exchange rate of 3 h⁻¹ effectively maintains indoor PM_2.5 levels below 35 μg/m³ for M6-F8 air filters. Experimental data demonstrate that when a fresh air system equipped with H10 filters operates at an outdoor PM_2.5 concentration of 150 μg/m³, the corresponding optimal ventilation rate is 0.45 h⁻¹. Increasing the mechanical ventilation rate to 1 h⁻¹ enables the system to effectively handle higher outdoor concentrations up to 176 μg/m³. Under severe pollution scenarios with outdoor PM_2.5 concentrations reaching 250 μg/m³, the air exchange rate should be further increased to 1.65 h⁻¹ to maintain indoor PM_2.5 concentrations within acceptable limits. This study provides practical insights for improving residential indoor air quality under high outdoor PM_2.5 conditions in Chinese cities. Full article