Biogenic acid resistance of calcium sulfoaluminate cement: Revelations from a field study

Biogenic acid attack of concrete is prevalent in sewers, posing a serious durability concern and financial burden. There are very limited number of field studies on durability of concrete under biogenic acid attack. Field study poses challenges with respect to the variation in climatic conditions and limited accessibility in sewers. Such a biogenic acid attack study in Indian conditions has not been performed. In this study, the biogenic acid resistance of Portland cement (PC) and calcium sulfoaluminate (CSA) cement-based binders under an in-situ sewer expo-sure is reported. The results show that the CSA-based binder used in this study outperformed PC in the biogenic acid resistance. The superior performance of CSA-based binder could be attributed to its acid neutralisation capacity offered by the aluminum hydroxide phase and bactericidal properties. For the first time, the bacteriostatic effect of CSA cement was demonstrated by analyzing the field exposed specimens.

Automated summary

Biogenic acid attack on concrete in sewers is a serious durability concern and field studies on this topic are limited. This study reports on the biogenic acid resistance of Portland cement (PC) and calcium sulfoaluminate (CSA) cement-based binders under in-situ sewer exposure. The results show that the CSA-based binder outperformed PC in terms of biogenic acid resistance, possibly due to the aluminum hydroxide phase for acid neutralization and bactericidal properties. The bacteriostatic effect of CSA cement was demonstrated for the first time through analysis of field exposed specimens.