Facing natural resource shortage challenge, Taiwan government has been aware of the importance of transformation from linear economy to circular economy. Public Construction Commission (PCC), Environmental Protection... [ view full abstract ]
Facing natural resource shortage challenge, Taiwan government has been aware of the importance of transformation from linear economy to circular economy. Public Construction Commission (PCC), Environmental Protection Administration (EPA), Ministry of Economic Affairs and local governments etc. are collaborated to promote the application of regenerated products on public works. In terms of construction and building materials, take roadworks as an example that bottom ash from incinerator had been chosen as the primary promoted regenerated resources. In Taiwan, bottom ash is produced 0.9 million tons per year. In the beginning, due to the non-sufficient confidence, the application was limited and subsequent to cause the waste disposal problem. Therefore, the mentioned government departments and organizations work on expanding the application ways as follows. Bottom ash is affirmed to be applied for controlled low strength materials (CLSM), graded aggregate subbase, graded aggregate base and low-density regenerated water permeable concrete. In Taiwan, CLSM and graded aggregate base and subbase demand 2.5 million tons and 1 million tons per year, respectively, which expectedly consumes 0.8 to 1 million tons of bottom ash annually. Asphalt concrete (AC), CLSM and graded aggregate base and subbase are chosen as the initial stage of application, because they are regarded as more acceptable for people. Our government believes that public works are able to accommodate more regenerated products by appropriate management. In order to widely, properly and fully apply the regenerated products, the “Construction Specifications” and user manual are revised and announced by the PCC and the producer. Ministry of Transportation and Communication applied 235 m3 of bottom ash on graded aggregate base and subbase of highway maintenance in Taiwan in 2011. Furthermore, Taiwan government encourages additional kinds of regenerated products used for construction and building materials on the premise of safety. Due to the goal of Taiwan government, this research attempts to find out the potential wastes. First, the potential categories of wastes are investigated, including municipal and industrial wastes. According to the EPA announcement of “Reuse Categories”, 21 categories of wastes are screened and deemed as the potential material for construction and building materials. Secondly, this research investigates the existing categories and amounts of wastes which are used by recycling industries from 2013 to 2017. At this stage, the top 5 categories of industrial wastes that are coal fly ash, electrical arc furnace (EAF) oxidizing slag, EAF reductive slag, coal bottom ash and waste glass sequentially, and bottom ash from incinerator are chosen. According to “Measures for Management of Reuse of Industrial Waste” and “Management of Reuse of Bottom Ash from Incinerator”, published by Taiwan government, the legislative applications of the aforementioned regenerated products are cement and its products, AC aggregates, concrete aggregate, CLSM and graded aggregate base and subbase. Thirdly, screening the properties and quality specifications of regenerated products in line with the requirements contained in the “Construction Specifications”. Lastly, in accordance to the applicable potential materials of construction and building, including the existing regenerated products are evaluated, and the related “Construction Specifications” are listed as well. The result of this research is a feasibility study of regenerated products using for construction and building materials. Based on this research, the tests for individual product are recommended and necessary in the future.
