Penetrability, Corrosion Potential, and Electrical Resistivity of Bacterial Concrete

Abstract

Concrete is one of the most widely used materials in building structures; hence, improving its durability is important. Corrosive agents affecting concrete durability find their way into concrete through surface cracks and pores. However, concrete can be made resistant to such destructive agents if calcite sediments are allowed to form in the concrete by certain types of bacteria. This study investigated the effects of certain bacterial agents on the electrical resistance, chloride penetrability, and steel corrosion of concrete specimens. The water absorption and compressive strength of the specimens were evaluated. For this purpose, concrete specimens were made using two different bacteria (S. pasteurii and B. subtilis) and two different mixture proportions. The specimens were cured for 28 or 91 consecutive days in two types of media (a solution of urea–calcium chloride and a solution of urea–calcium lactate). Results showed that the water absorption and chloride penetrability of the specimens decreased but their compressive strength and electrical resistance increased when bacteria, especially S. pasteurii, was used in the concrete. Moreover, the reinforcement provided enhanced resistance against corrosion in concrete specimens containing S. pasteurii and subsequently cured in the urea–calcium lactate medium.