Published Paper Details:

Self-healing concrete has established its effectiveness in repairing cracks, ultimately leading to improved durability. Additionally, there is a need to ensure that other crucial mechanical properties, particularly the strength of the intact (uncracked) material, remain uncompromised. When microorganisms are used, calcium carbonate precipitates in concrete. This precipitation will occur naturally as a consequence of biological activity and will be pollution-free. Despite CaCO3 precipitation being the primary component of the bacterial reaction product responsible for healing cracks and enhancing concrete strength, leveraging the effect of bacteria on concrete's mechanical properties could be subjective. This project reviews the impact of bacteria on mechanical properties, with a focus on the control (intact) strength of concrete and mortar under various conditions, with cementitious material replacement. In this project Bactaheal-PR is used as the bacteria in the concrete which helps in healing of the cracks in the concrete. In addition to the bacteria the cement is partially replaced with the fly ash which gives strength to the concrete. First the concrete is mixed without bacteria with the partial replacement of the cement with fly ash at various percentages of 6%, 8%, 10%, 12%, 30% and 40% and after curing takes place for 7, 28 days, the specimens are tested for compressive strength. Then the bacteria is added to the concrete of 0.25%, 0.5% with the partial replacement of cement with fly ash for the percentages of 12%, 30%, 40% and again the compressive strength test is carried out.The results show that comparing to the normal concrete the highest compressive strength is attained at 12% partial replacement of cement with fly ash without addition of bacteria. The optimum compressive strength is achieved at 12% partial replacement of cement with fly ash and with addition of 0.5% Bactaheal-PR bacteria. While comparing the concrete without bacteria the compressive strength is higher for the concrete with the addition of the bacteria. Comparing to the strength of the uncracked cubes the highest strength is attained by the crack healed cubes.