Quantifying the potential of recycling demolition waste generated from urban renewal: A case study in Shenzhen, China

Abstract

Large-scale demolition waste was generated during urban renewal. How to accurately quantify the potential of recycling large amounts of demolition waste has been widely considered a prerequisite for effective waste management, as it contributes to numbers and scales of recycling enterprises being managed and planned in advance. However, there is limited research, if any, focusing on this niche area. This study aims to quantify the potential of recycling demolition waste amidst urban renewal by considering actual market situations and different waste types. Firstly, the whole recycling process of demolition waste was scrutinized by using the free-flow mapping technique. Models for quantifying recycling potential of non-inert and inert demolition waste were then established, respectively, based on economic value and the principle of mass conservation. Finally, a case study was conducted to verify the models by putting them into the context of Shenzhen, a young and vibrating city in China but subject to massive urban renewal pressure. Results show that the recycling process of demolition waste is mainly divided into offsite and onsite recycling, both including five stages, viz., waste generation, on-site treatment, transportation, recycling, and product regeneration. In addition, different types of demolition waste have their respective recycling potential. The recycling potential of non-inert demolition waste is RMB 19,315.85 million yuan. In contrast, the recycling potential of inert demolition waste depends on types of recyclable products, with 18.41 million tons of recyclable bricks, 7.02 million tons of mortar, 28.36 million tons of aggregate, and 4.16 million tons of lightweight wallboard. Findings of this study improve the accuracy of the existing quantification methods. The research provides useful reference for the recycling industry to adjust production scale and arrange production sites to fully harness the waste recycling potential.