Deterioration law and mechanism of autoclaved aerated concrete under sulfate attack

Abstract

Autoclaved aerated concrete (AAC) is a lightweight porous material, which is widely used as wall material. However, the performance of AAC under sulfate attack is still unclear. Therefore, this experiment investigated the performance changes of AAC with different bulk densities in sodium sulfate solution. Meanwhile, the influence of B05 grade AAC under erosion by sodium sulfate, magnesium sulfate and ammonium sulfate solutions was studied separately, and the degradation degree of its performance in different concentrations of sodium sulfate solution was analyzed. Mass change, relative dynamic modulus of elasticity (E rd) and compressive strength, mineral phase and micromorphologies were investigated. The results revealed that E rd decreased more obviously with a higher bulk density class, but the variety of the compressive strength was inversed. Moreover, the performances of AAC samples degraded more significantly while they were exposed to sodium sulfate solution. With an increase in sulfate solution concentration, the performance of AAC deteriorated more seriously.