A review on protection of concrete for sewage installations and an accelerated test on protection systems

Biogenic sulfuric acid (BSA) attack against concrete structures has been reported for many years. This particular attack has been causing severe damages to structures with closed environments such as covered sedimentation tanks in sewage treatment plants. It is believed that BSA attack is the major cause of sewage concrete structure degradation. In order to inhibit the attack caused by BSA, numerous protective methods had been attempted. Measures such as epoxy coating, acidic inhibitors, admixtures were explored. Some accelerated tests were established to evaluate such attacks. In this paper, some commonly used testing techniques and methods are reviewed. The test results from an accelerated laboratory test established for this study on various concrete protection systems are presented and an in-situ test plan on coated concrete samples at a sewage treatment plant in Hong Kong is also outlined. © The Hong Kong Institution of Engineers.