廢棄混凝土再生利用成本效益分析之研究

BENEFIT/COST ANALYSIS FOR RECYCLING BUILDING CONCRETE WASTE

為釐清再生利用產品成本過高的傳統印象，並擴大廢棄混凝土之再生利用市場，本研究選定6項再生利用項目：道路基底層級配料、國家公園碎石步道、高壓混凝土地磚、植草磚、圍牆磚及消波塊（預拌混凝土）作為成本分析之對象，針對台灣北部地區土石方資源堆置處理場、營建廢棄物分類處理場、砂石場、混凝土製品廠等15家廠商，透過訪談調查方式，蒐集各種再生利用用途之各項成本結構資料，並探討廢棄混凝土再生利用所產生之效益。研究結果顯示，廢棄混凝土再生利用可達減少天然資源消耗及節省政府支出之效益，另道路基底層級配料、國家公園碎石步道、消波塊用預拌混凝土之再生材成本低於天然材成本，可列為優先推動之再生利用項目。

This study conducts a local analysis, from the perspective of public society, on the benefit and cost for recycling concrete wastes in Taiwan. Six recycling purposes and/or products are identified from previous studies and are investigated for cost breakdown and analysis. Twelve related players in the recycling process are interviewed with corresponding questionnaire. It is estimated that by recycling concrete wastes in Taiwan, 2.1 millions m3 of natural sand and stones can be conserved every year; NT$520 millions can be saved on landfills as well as on cleaning up the illegal dumping; and each municipal government can save more than several millions of NT dollars on reducing the manpower for monitoring and ticketing the illegal dumping of construction and demolition wastes. As for the cost concrete wastes, the analysis results show that to use recycled concrete for road base, for aggregate gravels of the walking path in parks, and for aggregates in batched concrete, can actually generate cost advantage over the natural products. As for the rest of recycling purposes and/or products investigated in this study, results shows a higher product or usage cost.