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Digital twin (DT) technology, integrated with building information modeling (BIM), enables real-time feedback and predictive analytics in construction. This study presents a BIM-enabled DT framework to optimize in situ production and yard-stock management of precast concrete (PC) components with a focus on minimizing CO2 emissions. Using Oracle Crystal Ball, scenario-based simulations revealed up to an 8.9% reduction in environmental impact. Distinct from prior research that largely emphasized cost or off-site strategies, this study uniquely addresses on-site sustainability by embedding carbon metrics into the decision-making process. The framework was validated through a large-scale logistics warehouse project that showcased its practical utility. This research contributes a replicable method for enhancing sustainability in precast construction through digital technologies.

The integration of Building Information Modeling (BIM) and Digital Twin (DT) technologies offers new opportunities for enhancing reinforcement design and on-site constructability. This study addresses a current gap in DT applications by introducing an intelligent framework that simultaneously automates rebar layout generation and reduces rebar cutting waste (RCW), two challenges often overlooked during the construction execution phase. The system employs heuristic algorithms to generate constructability-aware rebar configurations and leverages Industry Foundation Classes (IFC) schema-based data models for interoperability. The framework is implemented using Autodesk Revit and Dynamo for rebar modeling and layout generation, Microsoft Project for schedule integration, and Autodesk Navisworks for clash detection. Real-time scheduling synchronization is achieved through IFC schema-based BIM models linked to construction timelines, while embedded clash detection and constructability feedback loops allow for iterative refinement and improved installation feasibility. A case study on a high-rise commercial building demonstrates substantial material savings, improved constructability, and reduced layout time, validating the practical advantages of BIM–DT integration for RC construction.

If PC components are produced on site under the same conditions, the quality can be secured at least equal to that of factory production. In-situ production can reduce environmental loads by 14.58% or more than factory production, and if the number of PC components produced in-situ is increased, the cost can be reduced by up to 39.4% compared to factory production. Most of the existing studies focus on optimizing the layout of logistics centers, and relatively little attention is paid to the layout of PC parts for in-situ production. PC component yard layout planning for in-situ production can effectively reduce carbon dioxide emissions and improve construction efficiency. Therefore, the purpose of this study is to develop an environmental impact minimization model for in-situ production of PC components. As a result of applying the developed model, the optimization of the improved dung beetle optimization algorithm was verified to be efficient by improving the neighboring correlation by 22.79% and reducing carbon dioxide emissions by 18.33% compared to the dung beetle optimization algorithm. The proposed environmental impact minimization model can support the construction, reconstruction, and functional upgrade of logistics centers, contributing to low carbon dioxide in the logistics industry.

Reducing the construction time for large logistics buildings can result in reduced construction management costs and economic gains from early operation. A large logistics building with a heavy load and long spans was constructed as a precast concrete (PC) structure, which required the use of a sizable crane to lift heavy PC members. A basic analytical approach was employed to resolve potential errors in the planning of PC member erection and to build a systematic erection plan. Calculation techniques for the trajectory distance that use the crane location were applied to select an erection plan that minimizes crane work. A crane trajectory distance calculation algorithm for sustainable PC member erection in large logistics buildings with heavy loads and long spans has been developed. The developed model aids in creating simulation and optimization models to ensure the minimal usage of cranes in the future and in determining the cost, construction time, CO2 emissions, and energy use for each erection plan.

In South Korea, industrial accidents continue to increase in frequency, with construction accidents accounting for more than a third of all industrial accidents. Specifically, by preventing fall accidents, the death rate from accidents can be reduced by 50%. Fall protection is required to prevent fall accidents, and investigating the reinforcement of the worker’s safety harness and hook fastening becomes imperative. This requires automation of computer vision confirmation of the safety harness and hook fastening. As the accident risk can be reduced by an effective safety culture in the system, it is necessary to monitor safety on site through a construction safety automation system. Therefore, the objective of this study is to develop a computer vision process for safety harness and hook for preventing fall accidents in South Korea’s construction industry. This study focuses on system scaffolds that are widely used at construction sites. The application of this methodology to sample sites and field cases established its applicability. The proposed computer vision application methodology will serve as the foundation for visualization research in the construction industry, and image recognition will help reduce the safety accident rate. Accidents caused by failure to use a safety harness and hook can be reduced in South Korea as well as globally. Additionally, this methodology is applicable to roof construction, tower crane installation and dismantling work, as well as steel tower installation and dismantling.

Various studies have been conducted to construct free-form buildings, but it still takes a lot of labor, cost, and time to assure the accuracy of designed shapes. In particular, molds for the production of free-form concrete panels (FCPs) are putting enormous burdens on productivity and cost. To produce FCPs economically, a computerized numeric control (CNC) machine that produces phase change material (PCM) molds for persistent use was developed in this study. The technology using CNC machine can produce precisely free-form molds and panels in a short time compared to the manual method. However, in order to commercialize this technology, it is necessary to verify the shape error of the FCPs. Therefore, the purpose of this paper is an experimental study for securing FCP quality produced by a CNC machine. The results of this study will be used to mass-produce uniform quality of FCPs without depending on the skill and workmanship of the labor.

Lap splices are the most commonly used method worldwide because they do not require specific equipment or skilled workers. However, lap splices incur high construction costs because of the long splice lengths required for large-diameter rebars in megastructures, as well as issues pertaining to material supply, labor costs, constructability, and project duration. Additionally, approximately 15% more rebar is required because of the overlap. Energy saving for a sustainable built environment is possible if the disadvantage of lap splices, which generate high CO2 emissions due to the excessive use of rebar, are resolved. Hence, mechanical rebar couplers (MRCs) have been developed. However, despite their advantages, they have not been widely applied in construction sites owing to concerns regarding safety, quality, and constructability. This is because data on MRC, including maintenance, and environmental impact, are not organized, making it difficult to select a coupler suitable for the environment during the construction stage. Therefore, a data-driven approach for selecting MRCs based on the reinforcing bar shape and structural characteristics is proposed in this study. The T-epoxy filled sleeve coupler was found to be the best in terms of seismic performance, durability, corrosion resistance, and long-term performance. In addition, using a data-driven MRC selection algorithm using the T-threaded coupler for one rebar over two floors resulted in 56% more efficient labor productivity, 15% shorter assembly time, 17% lower costs, and 26% lower CO2 emission. Using a developed algorithm, the appropriate MRC can easily and rapidly be selected for frequent design changes.

3D-designs of free-form buildings are developed using a computer due to difficulty of shape implementation. When producing free-form concrete panel (FCP) using materials such as GFRC (glass fiber reinforced concrete), engineers or manufacturers should precisely calculate the offset value or geometry of each member at the junction point of three or more FCPs before it is constructed. However, it is difficult to calculate offset geometry easily and quickly, and no research has been conducted on this topic. Therefore, the objective of this paper is to develop a solution of subordinate vertices for quality connections of external free-form concrete panels. The developed mathematical solutions practically support the production of FCPs with precise installation to ensure aesthetic quality of the building. This paper academically contributes to the automatic creation of joint details of FCPs implemented by BIM.

CO2 emissions account for 80% of greenhouse gases, which lead to the largest contributions to climate change. As the problem of CO2 emission becomes more and more prominent, research on sustainable technologies to reduce CO2 emission among environmental loads is continuously being conducted. In-situ production of precast concrete members has advantages over in-plant production in reducing costs, securing equal or enhanced quality under equal conditions, and reducing CO2 emission. When applying in-situ production to real projects, it is vital to calculate the optimal quantity. This paper presents a dynamic optimization model for estimating in-situ production quantity of precast concrete members subjected to environmental loads. After defining various factors and deriving the objective function, an optimization model is developed using system dynamics. As a result of optimizing the quantity by applying it to the case project, it was confirmed that the optimal case can save 7557 t-CO2 in CO2 emissions and 6,966,000 USD in cost, which resulted in 14.58% and 10.53% for environmental loads and cost, respectively. The model developed here can be used to calculate the quantity of in-situ production quickly and easily in consideration of dynamically changing field conditions.

Electrical contractors encounter problems such as limited construction sites, schedule interference, and inefficient communication with other contractors when they typically subcontract with general contractors. Electrical projects require effective and systematic project management strategies to overcome these problems and achieve the desired goal. In an electrical construction project, individual tasks are interconnected at different stages, including pre-construction planning (PCP) and project execution (PE). Therefore, analyzing the effect of task strings on the project success in terms of schedule and cost performance is necessary. The main objective of this study is to perform a static analysis to compare successful and failed projects with a focus on the cost and schedule performances, using the PCP and PE task strings in electrical construction projects. To achieve this, a continuous PCP-PE task strings implementation score was calculated for each PE group in terms of cost and schedule, and successful and failed projects on unweighted and weighted values were compared and analyzed by performing an independent sample t-test. Consequently, it was confirmed that the use of most task strings had a positive effect on the cost success at a confidence level of 95%, and that only the subcontractor management group had a positive effect on the schedule success. Hence, it was derived that the usage of task strings for these groups is recommended for cost success in electrical construction, and continuous PCP-PE task strings do not have a positive effect on schedule success; therefore, it is recommended to use the PCP-PE task strings only for specific groups for schedule success in electrical construction. Demonstrating the relationship between the PCP and PE tasks, the findings of this study are expected to help electrical contractors achieve a better performance using effective project management strategies.