Durability and life prediction of fly ash geopolymer concrete in corrosion environments caused by dry and wet circulation
2022
Sun, Qi | Li, Botao | Wang, Yiting | Wang, Hui
The use of tailings, waste rock, fly ash, and slag to prepare geopolymer concrete can effectively solve the problems of land resources occupied by tailings and waste rock, low utilization rate, and environmental pollution. Using a dry–wet circulation method, fly ash for a different corrosion solution to geopolymer concrete (referred to as TWGPC) was analyzed. Through an appearance change, the corrosion resistance coefficient of the compressive strength, relative dynamic elastic modulus, tensile splitting strength, relative mass, and durability were investigated, using scanning electron microscopy (SEM) analysis of the microstructure, The life of TWGPC was predicted based on the GM(1,1) prediction model of grey system theory. The test results show that with an increase in the number of dry–wet cycles, the surface of the specimen crystallizes, cracks, spalls, and exhibits other phenomena. The compressive strength corrosion coefficient, relative dynamic elastic modulus, crack tensile strength, and relative mass show a trend of increasing first and then decreasing, finally reaching the peak value after 40 cycles. The erosion products generated by the early reaction fill the slurry aggregate pores and improve the strength of TWGPC. In a later stage, a large number of erosion products absorb water and expand; the internal pores of TWGPC are connected, leading to a decrease in strength. Cl⁻ inhibits the corrosion of SO₄²⁻ in concrete and improves the durability of concrete.
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