Search Results (68)

Prefabricated Ultra-High-Performance Concrete (UHPC) and cast-in-place Normal Concrete (NC) composite members are increasingly used in bridge engineering because they combine high performance with cost-effectiveness. The bond at the UHPC-NC interface is critical as it directly impacts the composite structure’s safety. This study employed 3D laser scanning acquired the UHPC substrate geometry, utilized fractal dimension analysis to quantify the interface roughness, and adopted the slant shear test to evaluate the effects of retarder application mass and hydration delay duration on roughness and bond strength. The research results indicate that the failure modes of UHPC-NC specimens can be categorized into interface shear failure and NC splitting tensile failure. With the extension of hydration delay duration, both the interface roughness and bond strength show a decreasing trend. The influence of retarder dosage on interface roughness and bond strength exhibits a threshold effect. This study also confirms the effectiveness of fractal dimension as a quantitative tool for characterizing the macroscopic roughness features of the bonding interface. The findings of this paper provide a solid theoretical basis and quantitative support for optimizing key process parameters such as retarder dosage and precisely controlling hydration delay duration, offering significant engineering guidance for enhancing the interface bonding performance of UHPC-NC composite structures. Full article

Conventional cast-in-place counterfort retaining walls, while widely used to support the fill body in geotechnical engineering cases, suffer from extended construction cycles and environmental impacts that constrain their usage more widely. In this study, in order to overcome these limitations, the performance of two types of innovative prefabricated counterfort retaining wall system—a monolithic design and a modular design—was investigated through physical modeling. The results reveal that failure mechanisms are fundamentally governed by the distribution of stress at the connection interfaces. The monolithic system, with fewer connections, concentrates stress and is more vulnerable to cracking at the primary joints. In contrast, the modular system disperses loads across numerous connections, reducing localized stress. Critically, this analysis identified a construction-dependent failure mode: incomplete contact between the foundation and the base slab induces severe bending moments that can lead to catastrophic failure. Furthermore, this study shows that complex stress states due to backfill failure can induce detrimental tensile forces on the wall structure. To address this, a composite soil material–wall structure system incorporating geogrid reinforcement was developed. This system significantly enhances the backfill’s bearing capacity and mitigates adverse loading. Based on the comprehensive analysis of settlement and structural performance, the optimal configuration involves concentrating geogrid layers in the upper third of section of the backfill, with sparser distribution below. Full article

To address the engineering issues of difficult quality control, complex construction processes, and long construction periods in cast-in-place protective walls for manually excavated piles, a prefabricated protective wall structure is proposed. This study aims to investigate its mechanical properties and key influencing parameters through experiments. Six groups of prefabricated wall segment specimens with different wall thicknesses (50 mm, 65 mm) and concrete strengths (C50 concrete, reactive powder concrete RPC) were designed, and two-point bending tests were conducted to systematically analyze their failure characteristics, crack development patterns, and strain distribution laws. The test results show that the peak vertical bending displacements at mid-span of the specimens are 11–18 mm (1.83–2.71% of the radius). The 65-mm-thick specimens exhibit 3–10% higher flexural strength than the 50-mm-thick ones, and reactive powder concrete (RPC) specimens of the same thickness show an 8.3% increase in strength compared to C50 concrete specimens. When the load reaches 80% of the ultimate load, abrupt changes in concrete strain occur at the mid-span and loading points, while the strain at the fixed end is only 15–20% of the mid-span strain. The prefabricated protective wall demonstrates superior deformation resistance, with vertical displacements (3–5% of the radius) significantly lower than those of cast-in-place walls. This research clarifies the influence of wall thickness and concrete strength on the mechanical properties of prefabricated protective walls, providing key mechanical parameters to support their engineering applications. Full article

Standardized information on the processes and requirements for information exchanges is critical to ensure accurate cost estimations. However, traditional methods based on 2D information lack the standardization and information required for efficient and reliable early commercial evaluation. This study aims to evaluate the effectiveness and efficiency of the information exchange model (EM-01) proposed for the commercial evaluation of industrialized timber projects. This study adopted two illustrative cases of projects to make a comparative analysis between the traditional method that prefabrication companies use and the EM-01. The evaluation focused on effectiveness, efficiency, level of certainty, and the user’s perception. The results indicate that both methods enable project evaluation. However, the EM-01 offers better efficiency by reducing work time, reduces uncertainty by minimizing assumptions, and improves the user’s perception of the reliability of the commercial evaluation. The EM-01 provides more standardized information and specific structural design data supporting the early commercial evaluation. This study supports the idea that incorporating standardized information into the processes and requirements for information exchanges enhances the accuracy and reliability of early commercial evaluation in industrialized timber projects. Full article

This study investigates the progressive compressive behavior of modular interior frames with rotary-type module-to-module inter-modular (M2M) connections under sequential column failure. A novel two-stage testing protocol was applied, compressing the left upper column to failure, followed by the right, to simulate realistic loading progression in prefabricated column-supported volumetric modular steel structures. Detailed refined finite-element models (FEMs) were developed and validated against experimental results, accurately capturing local and global responses with an average prediction error of 2–10% for strength and stiffness. An extensive parametric study involving varying frame configurations evaluated the influence of frame member geometric properties, connection details, and column/beam gap interaction on progressive collapse behavior. The results demonstrated that upper columns govern failure through elastic–plastic buckling near M2M joints while other members/connections remain elastic/unyielded. Increasing column cross section and thickness significantly enhanced strength and stiffness, while longer columns and prior damage reduced capacity, particularly during right-column loading. Conventional steel design codes overestimated column strength, with mean P_u,FEM/P_u,code ratios below unity and high scatter (Coefficient of variation ~0.25–0.27), highlighting the inadequacy of isolated member-based design equations for modular assemblies. The findings emphasize the need for frame-based stability approaches that account for M2M joint semi-rigidity, sway sensitivity, and sequential failure effects to ensure the reliable design of modular steel frames under progressive compressive loads. Full article

Corrugated steel plate shear walls (CSPSWs) exhibit excellent energy dissipation capacity and lateral resistance performance due to their unique “accordion structure”, making them a highly promising seismic component in prefabricated buildings. The assembled CSPSWs utilize bolted connections on both sides, which align with the energy-saving and emission-reduction trends of prefabricated construction. Compared to traditional welded connections, this method reduces the impact on frame columns during seismic deformation and allows for easier post-damage replacement. Through experimental and finite element analysis, this study systematically investigates the lateral mechanical behavior of assembled CSPSWs and compares them with flat steel plate shear walls (FSPSWs), revealing the stress mechanisms and failure modes of corrugated structures. Additionally, parametric analysis quantifies the influence of plate thickness, width/height ratio, and wave height on structural performance. Experimental results demonstrate that CSPSWs significantly outperform FSPSWs in out-of-plane displacement resistance and energy dissipation efficiency. Parametric analysis indicates that increasing plate thickness and width/height ratio enhances energy dissipation, while increasing wave height negatively affects energy dissipation capacity. This research provides theoretical support for the optimal design and engineering application of assembled corrugated steel plate shear walls. Full article

Connection systems are a critical component of buildings constructed with engineered wood products (EWPs), influencing structural integrity, durability, and construction efficiency. This systematic review categorises connection types into mechanical, adhesive, and interlocking systems and evaluates their structural performance, adaptability in prefabrication, applicable design standards, and modelling approaches. The review synthesises recent trends in EWP connection research, highlighting key developments in digital fabrication, reversible joints, and sustainable construction. Findings emphasise the need for standardisation, performance validation, and hybrid systems to support the wider adoption of prefabricated timber structures in environmentally responsible building practices. Full article

The construction industry, which is responsible for nearly 40% of global carbon emissions, is facing increasing pressure to adopt sustainable practices. Traditional construction methods often escalate resource depletion and waste generation, highlighting the need to prioritize sustainability. Life cycle assessment (LCA) is a significant tool for evaluating the environmental impacts of materials across different life cycle stages, yet its application is hindered by data complexities and uncertainties, particularly during the early design phases. Building Information Modeling (BIM) offers a transformative solution by centralizing and automating multidisciplinary data, thus streamlining LCA processes. This study addresses those existing gaps by proposing a structured methodology that integrates BIM with LCA to enhance their applicability during early design. The model leverages BIM’s capabilities to automate data extraction and enable real-time impact assessments by providing precise environmental evaluations of different construction methods. Focusing on modular prefabrication, 3D concrete printing, and conventional construction, this model comparatively evaluates environmental performance across different life cycle phases, highlighting distinct strengths and improvement areas. The Whole Building LCA reveals clear environmental differences, emphasizing modular construction’s substantial opportunities for enhancement to reduce critical impacts such as climate change and fossil depletion. This model supports decision-making, promotes circular economy principles, and aids the construction industry’s transition toward more sustainable practices. Full article

Understanding the complex interaction between sustainability drivers (SDs) and the sustainable development goals (SDGs) within construction practices is essential to accelerating the global construction industry’s transition towards sustainable development. The current study aims to establish a universal measurable indicator system that establishes relationships between SDs that are relevant to prefabricated construction (PFC) and specific SDGs. The developed indicators measure how effectively PFC aligns with and contributes to achieving the targeted SDGs. A case study in Sri Lanka is used to identify and validate the usefulness of key SDs in advancing PFC in developing economies. The research methodology comprised a literature search, a pilot study, a questionnaire survey targeting PFC stakeholders, statistical analysis, an SDG mapping process, and a case study-based demonstration. The statistical analysis highlighted a reduced overall project time, the efficient consumption of materials, and overall project cost savings as the most significant SDs. The factor analysis grouped these SDs into four categories, explaining 71.48% of the cumulative variance. A fuzzy evaluation confirmed the critical role of all driver categories in the effective diffusion of prefabrication. The developed indicator system establishes a structured connection between SDs, SDGs, impacts, stakeholders, and indicator types. The case study analysis highlighted the potential of precast construction and the use of modular design in disassembly approaches to improve sustainability outcomes, which would directly support SDG targets such as resource efficiency (SDG 8.4) and health and pollution management goals (SDG 3.9). The outcomes provide valuable insights for construction industry stakeholders in developing economies committed to improving construction efficiencies. The proposed indicator system also contributes to the global construction sector’s efforts toward achieving the goals of the 2030 Agenda for Sustainable Development. Full article

To address the limitations of traditional concrete barriers in practical applications, this study proposes a novel semi-assembled concrete barrier utilizing ultra high performance concrete (UHPC) as the barrier shell material. The thin shell of the barrier is prefabricated using UHPC and filled with normal concrete (NC) to form a protective structure. Finite element software is employed to simulate collisions between three models and the barrier, and the barrier safety is preliminarily assessed according to the Standard for Safety Performance Evaluation of Highway Barriers. A full-scale vehicle collision test validated the model, and an analysis was conducted. The results demonstrate that the established model exhibits a high accuracy. The peak value of the 25 ms collision force in this simulation can be used as the basis for static load design. None of the three vehicles exhibited overriding or riding phenomena nor did they deviate from their guide frames, and following collisions with three different vehicles, no overall damage was observed on the semi-assembled barrier. Occupant impact velocity (OIV) remained below 12 m/s, while occupant ride-down acceleration (ORA) stayed under 200 m/s². The barrier meets SB protection-level requirements; thus, the findings can offer theoretical support for promoting the widespread adoption of this new type of barrier. Full article

This research explores the development of a modular prefabricated concrete housing prototype, focusing on sustainability and flexibility. Supported by industry collaboration, it examines three key hypotheses: (1) a rigid geometric modular layout optimizing standardized panels while allowing spatial customization and adaptability, (2) a mixed construction system combining panels with pillars and beams for greater design flexibility, and (3) prefabricated concrete panels with integrated thermal insulation to enhance comfort. An analytical framework was developed based on modularity, flexibility, and sustainability, informed by an extensive literature review and applied to contemporary collective housing case studies. Insights from this analysis guided the development of a housing prototype that integrates modularity, adaptable construction, and sustainable principles. The proposed design follows the principles of design for assembly and disassembly (DFA/DFD), increasingly relevant in modern construction. The findings suggest that combining concrete solutions with thermal insulation, structured around a regular geometric grid, enables diverse housing typologies while ensuring cost efficiency through prefabrication. This approach challenges the monotony of conventional housing, offering visually engaging and functionally adaptable alternatives. It promotes architecture that balances efficiency, sustainability, and aesthetic value while addressing modern housing needs. Full article

This study analyses the many different parameters of the in-plane flexibility problem regarding the lateral behaviour of light timber-framed (LTF) wall elements with different types of sheathing material (FPB, OSB, or even reinforced concrete), as well as the thickness of the timber frame elements (internal or external wall elements). The analysis simultaneously considers bending, shear, and timber-to-framing connection flexibility, while assuming stiff-supported wall elements as prescribed by Eurocode 5. Particular emphasis is placed on the sliding deformation between sheathing boards and the timber frame, which can significantly reduce the overall stiffness of LTF wall elements. The influence of fastener spacing (s) on sliding deformation and overall stiffness is comprehensively analysed, as well as the different bending and shear behaviours of the various sheathing materials. The results show that reducing the fastener spacing can significantly improve the stiffness of OSB wall elements, while it is less critical for FPB elements used in mid-rise timber buildings. A comparison of external and internal wall elements revealed a minimal difference in racking stiffness (3.3%) for OSB and FPB specimens, highlighting their comparable performance. The inclusion of RC sheathing on one side of the LTF elements showed significant potential to improve torsional behaviour and in-plane racking stiffness, making it a viable solution for strengthening prefabricated multi-storey timber buildings. These findings provide valuable guidance for optimizing the design of LTF walls, ensuring improved structural performance and extended application possibilities in modern timber construction. Full article

In recent years, the disruption of the prefabricated building supply chain has led to increased construction period delays and cost overruns, limiting the development and popularization of prefabricated buildings in China. Therefore, this study established a vulnerability evaluation index system for the prefabricated building supply chain using the driving force–pressure–state–impact–response (DPSIR) framework. We employed the intuitionistic fuzzy analytic hierarchy process (IFAHP), the projection pursuit (PP) model, and variable weight theory to determine the indicator weights. The IFAHP was utilized to reduce the subjectivity in weight assignment and to obtain the degree of membership, non-membership, and hesitation of experts in evaluating the importance of indicators. The PP model was used to determine objective weights based on the structure of the evaluation data, and variable weight theory was applied to integrate subjective and objective weights according to management needs. We utilized Set Pair Analysis (SPA) to establish a vulnerability evaluation model for the building supply chain, treating evaluation data and evaluation levels as a set pair. By analyzing the degree of identity, difference, and opposition of the set pair, we assessed and predicted the vulnerability of the building supply chain. Taking the Taohua Shantytown project in Nanchang as a case study, the results showed that the primary index with the greatest influence on the vulnerability of the prefabricated building supply chain was the driving force, with a weight of 0.2692, followed by the secondary indices of market demand and policy support, with weights of 0.0753 and 0.0719, respectively. The project’s average vulnerability rating was moderate (Level III), and it showed an improvement trend. During the project’s implementation, the total cost overrun of the prefabricated building supply chain was controlled within 5% of the budget, the construction period delay did not exceed 7% of the plan, and the rate of production safety accidents was below the industry average. The results demonstrated that the vulnerability assessment method for the prefabricated building supply chain based on SPA comprehensively and objectively reflected the vulnerability of the supply chain. It is suggested to improve the transparency and flexibility of the supply chain, strengthen daily management within the supply chain, and enhance collaboration with supply chain partners to reduce vulnerability. Full article

The concept of circular economy (CE) has emerged as an effective strategy for addressing resource depletion, waste generation, and environmental challenges, offering a promising path towards a more sustainable future. In the building sector, adopting CE principles can significantly mitigate environmental impacts, minimize lifecycle costs, and promote sustainability throughout a building’s lifecycle. Using a mixed-method approach via a pre-interview questionnaire and semi-structured interviews with 10 sustainability experts, this study analyses the significance of 15 CE strategies in building construction projects, assessing their importance and ranking their potential for adoption. Furthermore, this study evaluates the feasibility of applying CE principles to different building types, including storage, industrial, commercial, residential, business, and healthcare facilities. The role of lifecycle stages including initiation and planning, design, procurement, construction, operation and maintenance, and end of life is examined to identify phases with the highest potential for successfully embracing CE principles. The role of stakeholders in driving change is also analyzed. The outcomes of this study reveal that the most feasible strategies include the use of renewable energy, design for durability and longevity, prefabrication, and offsite construction. The study findings indicate that storage, industrial, and business (office) buildings are the most feasible for CE application, while the initiation and planning and design stages are identified as critical phases for embracing CE adoption. Owners and designers emerge as the stakeholders with the greatest influence on CE implementation. The results of this study provide a comprehensive overview of the feasibility of CE adoption in the building sector. These findings offer valuable insights that can inform the development of targeted strategies to support the effective adoption of CE principles. Full article

Single-sided formwork supporting systems (SFSSs) play a crucial role in the urban construction of retaining walls using cast-in-place concrete. By supporting the formwork from one side, an SFSS can minimize its spatial footprint, enabling its closer placement to boundary lines without compromising structural integrity. However, existing SFSS designs struggle to achieve a balance between mechanical performance and lightweight construction. To address these limitations, an innovative instrumented SFSS was proposed. It is composed of a panel structure made of a panel, vertical braces, and cross braces and a supporting structure comprising an L-shaped frame, steel tubes, and anchor bolts. These components are conducive to modular manufacturing, lightweight installation, and convenient connections. To facilitate the optimal design of this instrumented SFSS, a physics-constrained generative adversarial network (PC-GAN) approach was proposed. This approach incorporates three objective functions: minimizing material usage, adhering to deformation criteria, and ensuring structural safety. An example application is presented to demonstrate the superiority of the instrumented SFSS and validate the proposed PC-GAN approach. The instrumented SFSS enables individual components to be easily and rapidly prefabricated, assembled, and disassembled, requiring only two workers for installation or removal without the need for additional hoisting equipment. The optimized instrumented SFSS, designed using the PC-GAN approach, achieves comparable deformation performance (from 2.49 mm to 2.48 mm in maxima) and slightly improved component stress levels (from 97 MPa to 115 MPa in maxima) while reducing the total weight by 20.85%, through optimizing panel thickness, the dimensions and spacings of vertical and lateral braces, and the spacings of steel tubes. This optimized design of the instrumented SFSS using PC-GAN shows better performance than the current scheme, combining significant weight reduction with enhanced mechanical efficiency. Full article