Durability of manufactured sand concrete in atmospheric acidification environment

Abstract

In order to explore the possibility of replacing river sand with manufactured sand in concrete structures under atmospheric acidification environment, accelerated carbonation test and dry-wet circling test of sulfate attack was conducted in the laboratory. The surface damage, mass change, cube compressive strength and carbonization depth of manufactured sand concrete and river sand concrete were compared, and the products were analyzed by scanning electron microscopy. The results show that the surface of concrete is seriously damaged after sulfate attack, while the damage caused by carbonization is slight. In the accelerated carbonation test, the compressive strength of manufactured sand concrete increases faster than that of river sand concrete in the early stage, but the strength is opposite in the later stage. The compressive strength of both types of concrete decreases gradually under sulfate attack, but the strength of manufactured sand decreases more gently. Due to the stone powder in manufactured sand has a positive effect on the pore filling of concrete, it is beneficial to the use of manufactured sand concrete in atmospheric acidification environment.