A study on the effect of pH conditions on the properties of self-healing mortar cubes

This paper discusses the effect of pH on the various properties of the self-healing mortars (SHM). The bacteria induced structures have the ability to heal cracks generated on its surfaces by precipitating minerals inside the pores which bio mimics the natural healing processes occurring in nature, thus being an environment friendly technology that contributes in maintaining the structural durability. The microbiologically induced precipitation accelerates at different rates at different conditions. Hence an attempt has been made to analyse the changes in the properties in mortar cubes induced with 10⁵ cells/ml concentration of Bacillus megaterium solution and subjecting them to different curing media at different pH conditions. The healing efficiency of the cracks induced in the mortar cubes are evaluated visually for successive days. Through X-ray Diffraction analysis the white powder covering crack surface is confirmed to be calcite. The percentage reduction in the compressive strength of the samples after healing was found to be only 3% after 28 days of curing. The findings of the paper suggest promising application of self-healing mortar cubes at different geographical locations by varying the amount of bacterial solution.