Effect of flow rate on spatio-temporal deterioration of concrete under flowing sulfate attack

Abstract

Flowing effect on concrete deterioration caused by sulfate attack at varying flow rates was studied. It was found that an increased flow rate can expedite the weakening of the concrete's elastic modulus in the short term, thus causing an earlier onset of this weakening. However, the long-term deterioration of the elastic modulus remains unaffected by the flow rate due to the limited amount of products responsible for concrete deterioration. Notably, the deterioration depth or rate of the elastic modulus increases with higher flow rates due to the scouring effect of sulfate flow. To quantify this acceleration effect, an acceleration coefficient was defined, representing the impact of flow rate on the weakening process of concrete. It is approximately 1.20 for every 0.5 m/s increase in flow rate within the tested range. This coefficient provides a useful metric to assess the durability of concrete to sulfate attack under varying flow conditions.