Comparative Study of PPC M40 Grade Bacterial Concrete (Bacillus Subtilis) & Conventional Concrete

Abstract

Abstract Concrete’s activity lifespan begins to decrease as soon as cracks begin to form, which are unavoidable regardless of mix design or formulation. Self-healing concrete by microbiologically induced calcium carbonate precipitation is one such method to prevent cracks from causing structural degradation because they gradually allow water and other materials to pass through. Numerous technologies and studies are being developed to address this issue. Concrete of this kind is capable of initiating biological activity autogenously and repairing itself. Experimental testing is done in this study to demonstrate how the Bacillus Subtilis bacteria affect the properties of PPC M40 grade concrete. The experiment consisted of comparing OPC (ordinary Portland cement), PPC (Portland pozzolana cement), and BACTERIA STIMULATED PPC CONCRETE of the same grade (M40). Bacteria (Bacillus subtilis) were used in PPC concrete in volumes of 10 ml, 20 ml, and 30 ml, with concentrations of 10^8 cells per ml, in order to determine the optimal dose for maximum strength. At 7 days, 14 days, and 28 days, samples of concrete were subjected to compressive strength, split tensile strength, and flexural strength tests. The experimental outcomes show that PPC-based bacteria(30ml) actuated substantially shows a limit of 30% increment in compressive strength, 29.88% increment in flexural strength and an 11.9% increment in split tensile strength than conventional concrete. The Scanning Electron Microscope (SEM) technique demonstrated the growth of nanoparticles of filler material that are calcite precipitates, which densifies the concrete and increases its strength. This confirmed the presence of calcite deposition.