A feasibility analysis of waste concrete powder recycling market establishment: Hong Kong case

The construction industry has been focused on sustainability, particularly with regards to reducing CO2 emissions and recycling construction and demolition (C&D) waste. This study focuses on the alternative technology adaptation of carbonized pavement compact production by using waste concrete powder (WCP) which can be a substitute material to concrete and also able to absorb CO2. While material scientists embraced and developed this technological application, the financial perspective for adopting this technology has yet to be properly addressed. This paper conducts a feasibility assessment, which includes technical, environmental, social, and financial factors, from different stakeholders' perspectives (government, construction contractors, and material manufacturers) to launch the production of carbonized pavement compact by utilizing WCP. The benefit-cost analysis underlies the Evolutionary Game Model functions' formulation, which emphasizes not only the obvious financial benefits from WCP or its carbonized compacts sale but the benefits from the absorption of CO2 during the compacts production and avoiding WCP disposal at a landfill. The results based on a Hong Kong case (typical multistorey apartment building) identify promising scenarios where a minimum of 2300t of WCP is required for stakeholder interest in recycling, and a WCP wholesale price of 150HKD/t is suitable for the C&D contractor to participate in the recycling market. The study also estimates a cost-effective selling price of finished carbonized WCP compacts, which is competitive with similar products on the market. Important insights are drawn to initiate the WCP market and consequently increase the sustainability of the C&D recycling market.