Biogenic Sulfuric Acid Attack and Case Studies


Biogenic sulfuric acid attack (BSA) is probably the most common and most severe biodegradation mechanism affecting concrete. BSA deterioration is generally manifested as exfoliated surface loss with aggregate exposed, discoloration, and progressively altered zones with varying composition and texture in the existing concrete.

In this article, concrete experts Hugh Hou, Kimberly Steiner, John Fraczek, and Jim Mahaney discuss two case studies: a relatively new waste digester; and a decades-old sewer tunnel structure. The focus of the discussions is on distinct compositional and textural characteristics and variations from the exposed surface to sound concrete in these BSA-affected structures.

This article was originally published in Concrete International, the official publication of the American Concrete Institute.