This project aims to obtain the environmental quality and the characteristics of recycled aggregates with different dissolution approaches, and to evaluate the potentially improvement the process of recycled aggregates production. Based on the results, the environmental quality standard and management strategies under the aspects of life cycle is proposed. The project executed from June 5, 2018 to December 31, 2018. The major goal of this projects include: (1)Evaluate the feasibility of applying advanced resources treatment technology and upgrading the production process; (2) Determine the examination approaches of environmental quality items and related standards for incineration recycled aggregates; (3) Revise and review the current management strategies of recycled aggregates. The major results are summarized as follows: 1.Recycled aggregates products samples from 18 incineration plants are collected, and executed the physical and chemical properties testing, as well as the environmental quality testing. The physical and chemical properties testing of recycled aggregates included the specific gravity, water absorption, soundness, and resistance to degradation of coarse aggregate by abrasion and impact in the Los Angeles machine. Environmental quality testing of recycled aggregates included heavy meatal toxicity characteristic leaching procedure(TCLP), JIS K0058-1 leaching test and JIS K0058-2 test method for acid extractable contents of chemicals, up-flow percolation test(3 sets, 21 samples), dioxins toxicity (7 samples), pH, extraction chlorine ion concentration(L/S=10), and heavy metal analysis (9 samples). In addition, the recycled aggregates made as the CLSM products from Taoyuan City, Wuri and Xizhou incineration plants are processed toxicity characteristic leaching procedure, respectively. 2.Evaluate the current resource treatment procedures and propose revised recommendations refer to the advanced technologies from foreign countries, and to estimate the cost, environment and application benefits of upgrading the current treatment procedures. According to the analysis results of recycled aggregates from domestic institutions this year, the heavy metal content and the pH value of recycled aggregates play the important role in quality improvement. In order to improve the recycled aggregates quality, it is recommended to enhance the pretreatment procedure of sorting, stabilization, aging and water washing units. Adding a water washing unit can increase the iron/non-ferrous metal selection efficiency, and improve the quality. If adding an advanced sorting and washing units in current institution, the treatment cost increase approximately by 800 to 1,060 NT dollars per tons of recycled aggregates. 3.Assess the management logic and detection approaches of incineration recycled aggregates in Netherlands and Japan, and complete the proposed testing procedures, analysis items, frequency and standards for recycled aggregates management. According to the Japan slag resources products testing method, JIS K0058-1 leaching test and JIS K0058-2 test method for acid extractable contents of chemicals, we proposed that “Recycled Chemical Substances Environmental Dissolution Procedure” and “The Acid Extractable Procedure for the Chemicals Substances of Recycled Products ”in Taiwan. We recommend the control standard for “Recycled chemical substances environmental dissolution procedure” follows the regulation of “Groundwater pollution control standards.” 4.In order to promote a variety of usage and enhance management of recycled aggregates products, it is recommended to revise the application and management strategies with two quality standards in accordance with the current recycled aggregates delivery standards, and the usage classification of recycled aggregates. Based on the delivery standards and usage classification, the recycled aggregates products can be classified into three categories, including Type-I aggregates products, Type-II aggregates products, and Type-III specifics aggregates products, type of which is used for cement raw materials and sanitary landfills.

Incineration bottom ash, Recycle aggregate, Leaching Test