Investigation of Bacterial Activity on Compressive Strength of Cement Mortar in Different Curing Media

Recently, bacterial concrete is gaining popularity due to the advantages such as self healing property, increased durability, enhanced strength etc. When living organisms are introduced into cementitious materials, many factors are expected to influence their activity. A conducive environment such as temperature, nutrients, pH etc. is necessary for the survival and intended activity of bacteria in concrete. Among all the influential factors, nutrients for the survival of bacteria in cement mortar is considered in this study. In order to supply nutrients for the bacterial growth, three different curing media such as normal water, Luria Bertania broth (controlled nutrients) and wastewater (uncontrolled nutrients) are chosen. Compressive strength are determined at various stages of curing to study the influence of bacterial activity in cement mortar. Further, X ray diffraction and thermo gravimetric analysis are carried out to understand the transformation in hydration phases with the incorporation of bacteria. From the strength study conducted, cubes cured in waste water showed more strength which indicates that the bacterial activity is more in waste water.