Development Of Self-Healing Concrete With The Addition Of Bagasse Ash As Partial Replacement Of Cement

Abstract

Concrete is one of the most widely used building materials in the world. However, over time cracks may appear due to various reasons, on the concrete structure. This can lead to serious problems even permanent structural failure. Thus, it needs quick and continuous repairing. However, repairing is costly and time-consuming. For this reason, we have developed a self healing mechanism in concrete to extend the service life of the structure. This study describes the production of self-healing mortars, that can repair its crack. The specimen was produced using bacteria (Bacillus subtilus) with two different bacterial concentrations (10-7 , 10-9 cells/ml), calcium lactate, Portland cement, fine aggregate & water. In the presence of moisture, the bacterial spores become active and start to feed the nutrient (calcium lactate) and precipitate calcium carbonate, and filling the crack. In our research, cracks below 0.6 mm were completely closed or healed by self-healing mechanisms. Furthermore, we tried to lower the costs of self-healing mortars by synthesizing calcium lactate from waste eggshells and lactic acid. Additionally, we studied the controlled burned bagasse ash forthe replacement of Portland cement to enhance the strength of mortars and to reduce the costs of cement. The result indicated that the controlled burning bagasse ash increased the strength of mortars at early ages (up to 28 days) up to 10% replacement level. Bagasse ash was replaced in the ratio of 0, 5, 10, 15,20, and 25% by weight. We also tested the effect of cement type (OPC and PPC) on the Bagasse ash blended mortars and the result shows that BA-OPC achieves higher strength up to 10% replacement level relative to reference mortar’s sample. However, none of the PPC-BA mortars have shown any improvement in strength. Further, we evaluate the influence of Bacteria (bacillus subtilus) on Bagasse ash blended mortar and showed that the inclusion of bacteria improves the compressive strength of mortar samples. Samples were characterized by their properties using SEM, TGA, XRD, and FTIR analysis, and the performance of mortars was evaluated by mechanical and durability tests