Modeling Construction and Demolition Waste Recycling Program in Bangkok: Benefit and Cost Analysis

In Bangkok, many infrastructures have been built to satisfy the needs of the rapidly developing economy, leading to much higher construction and demolition (C&D) waste than ever before. A recycling program is, therefore, needed to properly manage the waste and to avoid landfill shortages and future environmental problems. This research examines the feasibility of a construction and demolition waste recycling program in Bangkok, Thailand, using a system dynamics (SD) modeling technique. The model consists of two main elements, namely the total benefits and total costs. The simulation results show that it takes 14years for the recycling program to be worth the investment. However, with the minimum acceptable internal rate of return (IRR) of 12% for most government projects, the recycling program must be continued until the end of Year 17 to be considered feasible. The results also show that saving in landfill charges and green image are the two key benefits in the recycling program. This could be seen from the high impact of the recycling rate and green image rate parameters on the construction and demolition waste recycling program. The developed dynamic model provides a better understanding of the construction and demolition waste situation in Bangkok, and plans for an effective waste management in the long term.