Analysing the impacts of key factors on the price of recycled concrete: A system dynamics model

Abstract

Effectively managing and utilizing the construction and demolition (C&D) waste is crucial for achieving sustainability goals. Recycling C&D waste into useable materials, such as recycled aggregate, for concrete production, offers both environmental and economic efficiency. Although recycled concrete is considered a viable alternative to virgin concrete, this product is not widely accepted in the construction industry. Insufficient price competitiveness is an essential obstacle. Therefore, investigating the factors influencing the price of recycled concrete is important for controlling it to an acceptable level. This study aims to develop a system dynamics model to evaluate dynamic effects of the key factors on the price of 30 MPa recycled concrete from short-term and long-term perspectives. Chongqing, China is selected as a case study. From the short-term perspective, the price of 30 MPa recycled concrete can be reduced to 84.11 % of that of virgin concrete. The most influential scenario for reducing the price of 30 MPa recycled concrete is incorporating 40 % ground granulated blast furnace slag (GGBFS) as a cement replacement in recycled concrete with a 100 % replacement rate of virgin coarse aggregate with recycled aggregate. From the long-term perspective, provision of subsidies for producing recycled concrete with a 25 % replacement rate can be effective in improving the supply. For the consumption, the mandatory use of recycled products from C&D waste and reducing tax for recycling activities are among the top five influential scenarios. This study fills a gap in the literature and provides industry practitioners with valuable insights into developing informed pricing.