The Effect of Bio-Deposition on Mechanical Performance of Cement-Based Materials

Applications of concrete are expanding rapidly all over the world, in a way that approximately 7% of the entire CO2 emit into the atmosphere by human pertains to the interventions made to nature in order to produce concrete. Hence, the need for producing types of concrete that are more compatible with sustainable development is felt more than ever. Finding novel methods for making cement-based materials to reduce cement consumption and the resulting pollution are of great importance among researchers. Improving the properties of these materials using microbial calcite sediments is an environment-friendly technique with an acceptable performance. To improve the compressive strength of cement mortar, microbial calcite sediments produced by Bacillus Subtilis and Sporosarcina Ureae bacteria types were used in this study. Recent studies were also investigated in this paper. To examine the effect of the culture environment, two general designs (with and without extra urea) with different concentrations of zero to 106 cells per milliliter were developed. Moreover, to study the effect of the curing method, two processing curing schemes (in distilled water and in a mineral-containing nutrient environment) were considered. The results show the proper effectiveness of this method, in a way that up to 35% increase in the samples’ compressive strength may be observed depending on bacterium type and curing method.