Bio Cementation Process in the Concrete using Bacillus Subtilis: A Statistical Modeling Study

The present study shows the bio-cementation efficacy of Bacillus subtilis incorporating three major parameters namely bacterial concentration, curing time, and nutritional proportion. Batch studies incorporating one variable at a time (OVAT) and central composite design (CCD) along with the response surface methodology (RSM) were undertaken to establish the possible relationship of selected parameters with the mechanical properties (compressive strength, flexural strength and split tensile strength) of cement mortar and bacterial concrete. The investigations performed on the basis of OVAT approach indicated that the extreme level of bacterial concentration, curing time, and nutritional proportion produced the highest improvement in mechanical properties of bacterial concrete producing compressive strength, flexural strength and split tensile strength of 79.5 MPa, 6.22 MPa, and 5.01 MPa respectively. Inline to OVAT approach, analysis of variance (ANOVA) also depicted that the individual as well as some of the possible two factor interactive model terms appeared as significant model terms with p-value was less than 0.05. The response predictive efficacy of the model was ascertained with a high R2 value (0.99) and high adequate precision.