Accelerated carbonation in cement paste samples with bacteria samples

Abstract

In reinforced concrete structures damage can occur at different stages of the service life, these can only affect the appearance, but can also compromise the strength and durability of the structure.

Microbial induced calcium carbonate (CaCO3) precipitation is a phenomenon used in the development of self-repairing cementitious materials.

The natural carbonation process produces a decrease in pH, which, if it reaches the armour, can lead to corrosion.

The work aims is to evaluate the interaction between the carbonation process and the evaluation of microbial induced calcium carbonate precipitation. For this purpose, experimental cement mixtures were formulated using UME aqueous medium and bacteria as mixing water. The presence of urea and bacteria within the matrix would allow to obtain CaCO3 and NH3 (ammonia), resulting in a balanced pH.