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Title |
Assessment on the Physical and Chemical Properties of Granulated Ground Waste Concrete Powders Compiled from Waste Concrete and Mortar
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Authors |
김도겸(Do-Gyeum Kim) ; 양근혁(Keun-Hyeok Yang) ; 서은아(Eun-A Seo) ; 윤현섭(Hyun-Sub Yoon) |
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DOI |
https://doi.org/10.4334/JKCI.2021.33.4.327 |
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Keywords |
폐콘크리트 미분말; 재활용; 소성; 재수화; 활성도 지수 granulated ground powders; waste concrete; recycle; calcination; re-hydration; activity index |
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Abstract |
This study examined the physical and chemical properties of granulated ground waste concrete powders (GGWCPs) isolated and sorted from waste concrete and mortar as part of fundamental research on the recycling of radioactive-dismantled concrete. As dry treatment processes for compiling GGWCPs, crushing, calcination, and re-hydration were considered. The properties and activity index measured in GGWCPs were compared with conventional values and minimum requirements specified in standard provisions, wherever possible, for cementitious materials, such as ordinary Portland cement (OPC), fly ash (FA), and ground granulated blast furnace slag (GGBS). The class the specific surface area of the re-hydrated GGWCPs could be estimated as 4,000 cm2/g, which satisfied the minimum requirements of 2,800 cm2/g specified in ASTM C150 for OPC. The main chemical compositions of GGWCPs were CaO and SiO2, which is similar to OPC. The GGWCP samples compiled from the calcination and re-hydration treatments exhibited lower mass reduction of cement hydration products (portlandite and calcite) in thermogravimetry-differential analysis than the counterpart samples treated by crushing. The 28-day activity index of GGWCPs treated by calcination possessed reached 80 %, which is comparable to the minimum requirements for second-grade FA and third-grade GGBS.
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