Influence of HCl corrosion on the mechanical properties of concrete

Corrosion damage in three types of concrete (C25, C45, and C55), resulting from HCl with various contents, was investigated by comparing the mechanical properties of different types of concrete and their corrosion damage. The test samples that were cured for 360 days were exposed in an aggressive environment (with 5%, 10%, 15%, and 20% HCl content, respectively) for 24 h. The mass loss, the dynamic modulus loss, the flexural strength, and the compressive strength were measured using a series of the etched samples. The results indicate that the mechanical properties of concrete were degraded with the increasing HCl content of the corrosion medium. The etched samples of both the high- (C55) and normal-strength concretes (C25) exhibited the similar degradation of compressive strength. On the other hand, due to its greater sensitivity to defects when bending load is applied, bending strength showed greater decline in the high- than in the normal-strength concrete, which has greater loss of mass and elastic modulus.