Properties and environmental impacts on repeated recycled aggregate concrete
WANG Zhen-shuang1, SU Hao-lin2
1. School of Investment & Construction Management, Dongbei University of Finance and Economics, Dalian 116023, China;
2. School of Naval Architecture, Shanghai Jiaotong University, Shanghai 200240, China
According to the cradle-to-gate life cycle evaluation method and taking into account the environmental impact distribution of concrete recycling, this research studies on properties and environmental impacts of repeated recycled aggregate concrete, and the optimum number of repeated regeneration of concrete is optimized on efficiency function method. The results concluded that, the slump, strength and electric flux decreased with cycles of repeated regeneration of concrete increasing, the 28d compressive strength 33.3MPa after 3repeated cycles, which arrived the design strength requirements. Compared with ordinary concrete, the slump decreased by 38.9% and electric flux increased by 85.7%, respectively; The ecological efficiency of concrete material increases with the repeated cycles increasing, the values of GWP, CED, and CMR of concrete materials are reduced with the increase of the repeated cycles increasing, The reduction variation from high to low is:CMR > GWP > CED; Taking into account the slump, the compressive strength, the electrical flux, the GWP, the CED, and the CMR in four concrete mix scenarios, the total efficiency coefficient of concrete from high to low is:the first generation recycled concrete > the second generation recycled concrete > the third generation recycled concrete > ordinary concrete.
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