The decisive role of the abrasion stress in concrete corrosion during acid attack – Comparison of resistance of different concrete types

Abstract

Biogenic-produced sulfuric acid (BSA) attack, described as microbially induced concrete corrosion (MICC), reduces lifespan of concrete elements in sewage systems worldwide. Wastewater containing solids (e.g., sand) may cause abrasive stress to the concrete with increased flow intensity and thus accelerate the development of corrosion at the sewage/air interface in the tidal zone. The impact of drying and wetting cycles is also important; therefore, all these factors were included in the testing method. Overall, this paper evaluates the development and extent of corrosion after a pure chemical acid attack combined with a mechanical abrasion in the form of brushing. To simulate the wetting and drying cycles of corrosion, samples were partially immersed in an aggressive solution. The investigation comprised comparing the acid and abrasion resistance of three types of concretes – ordinary Portland cement concrete (OPC), sulfate-resistant concrete (SRC), and white ordinary Portland cement concrete (WOPC). The impact of abrasion on the individual parameters of corrosion, e.g., the amount of leached calcium, acid consumption, and damage depths, were also discussed. The results showed that mechanical abrasion in the form of brushing promotes acid penetration; however, there are differences depending on the type of concrete.