Study on the Deterioration of Concrete and Internal Evaluated Strength Distribution Exposed to Sulfuric Acid Environments
By Naoki Aoyagi, Yusuke Yoshida, Ichiro Iwaki and Takashi Mimura
Concrete Research and Technology
Vol.15, No.1, Jan 2004 (Issue 34)
- Synopsis:
- Recently, the early deterioration of concrete structures caused by sulfuric acid was found in sewerage system. In this study, mortar specimens were exposed to sulfuric acid. The influence of W/C, sulfuric acid concentration and air content on the deterioration process was investigated. Internal evaluated strength was also measured using the Needle penetration method. The experimental results revealed that in the case of high sulfuric acid concentration deterioration was evident by large amount of surface erosion. In the case of low concentration deterioration was mainly due to the penetration of acid into the mortar. The use of Air Entraining Agent was found to inhibit the deterioration process. It was found that the internal evaluated strength distribution depended on the W/C and concentration of sulfuric acid. The reduction in evaluated strength occurred even beyond the neutralization depth of mortar.
- Keywords:
- sulfuric acid attack, erosion depth, neutralization depth, a needle penetration method
