Durability and life prediction of fly ash geopolymer concrete in corrosion environments caused by dry and wet circulation

Abstract

The use of tailings, waste rock, y 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, y ash for a different corrosion solution to geopolymer concrete (referred to as TWGPC) was analysed. Through an appearance change, the corrosion resistance coe cient 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 coe cient, relative dynamic elastic modulus, crack tensile strength and relative mass show a trend of increasing rst and then decreasing, nally reaching the peak value after 40 cycles. The erosion products generated by the early reaction ll 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. Clinhibits the corrosion of SO 4 2in concrete and improves the durability of concrete.

Dry–Wet Cyclic Sulfate Attack Mechanism of High-Volume Fly Ash Self-Compacting Concrete

“…Particularly in acidic groundwater and high-clay soil environments, sulfates are contained in most cases, and the concrete itself may also contain sulfate. Therefore, under the above conditions, concrete will be eroded, causing concrete expansion, cracking, spalling, and other phenomena, causing the loss of strength and viscosity, leading to the destruction of the internal mechanism, which ultimately affects the durability of concrete [10].…”