The global increase in construction and demolition wastes, such as concrete debris and concrete formwork, has raised concerns. Consequently, the improper management of these wastes has resulted in a significant waste of natural resources like minerals and construction, increasing the construction costs. In response, countermeasures have been enacted to reduce the amount of waste and increase cost savings. Among these measures, reuse and recycling of construction wastes have been widely implemented as an effective strategy to save costs and reduce the environmental footprint of the construction and building industry.
Lately, the need to reuse concrete formwork has escalated. Generally, concrete formwork is used to support and shape concrete components during construction, after which they become useless and get disposed of upon construction completion. Previous research findings have revealed that the useless concrete formwork can be recycled to improve on-site utilization. Its benefits include contributions to material waste reduction and waste recycling efficiency and cost savings for construction sites. Additionally, since most materials used as concrete formwork are made of wood and bamboo, recycling concrete formwork contributes to resource conservation and prevents deforestation.
Nevertheless, despite the well-planned on-site reuse of formwork, there are a significant amount of formwork panels being wasted before exhaustion of their surplus reuse values due to many factors like completion of construction activities or change in schedules. While this can be avoided by promoting formwork reuse among different constriction sites in the supply chain, it remains an unexplored area. Moreover, on-site formwork reuse among construction sites is generally complex due to additional dynamic reuse processes, which must be solved to facilitate the efficient reuse of concrete formwork in the supply chain.
Herein, researchers from Chongqing Jiaotong University: Dr. Zhongya Mei, Professor Maozeng Xu and Dr. Siyu Luo in collaboration with Dr. Yi Tan from Shenzhen University and Professor Heng Li from The Hong Kong Polytechnic University analyzed the dynamic processes of concrete formwork reuse among constriction sites for minimizing the overall consumption of formwork and construction costs of all sites involved. The authors commenced by first developing a mathematical model to analyze the usage of formwork on a single site. Next, agent-based modeling and simulation and discrete events were used to simulate concrete formwork reuse among constriction sites considering the dynamic changes in the supply chain. The work is published in the journal, Journal of Cleaner Production.
The authors demonstrated the feasibility of the presented model in simulating the dynamic processes of reusing formwork in the entire supply chain comprising four major decision-making agents: construction sites, formwork suppliers, transportation trucks and waste disposal centers. Based on the asymmetric information, the integration of the negotiation protocol in the agents’ behaviors facilitated interactions and efficient decision-making. The agent-based modeling also generated the optimal strategies for reusing formwork among construction sites. The Chongqing case study results showed that the formwork reuse in the supply chain has several benefits than its reuse in a single site and results in 25.38% cost saving, 33.56% quantity reduction, and 73.18% surplus reuse value reduction.
In summary, the study provided a robust and feasible approach for analyzing the dynamic processes of reusing formwork among construction sites to simultaneously reduce the formwork wastes and minimize construction costs. The mathematical and agent-based modeling and simulation models employed provide the basis for facilitating the interaction and efficient decision-making by considering the strategies used to make key decisions at each construction site. In a statement to Advances in Engineering, Professor Maozeng Xu stated that concrete formwork reuse among construction sites would improve the utilization of construction materials, thereby contributing to the sustainable development of the construction sector.
Mei, Z., Xu, M., Luo, S., Tan, Y., & Li, H. (2022). Concrete formwork reuse in a supply chain with dynamic changes using ABMS and discrete events. Journal of Cleaner Production, 332, 130038.