Fracture behavior study of self-healing bacterial concrete

Abstract

Presently, the construction sector expects quicker strength attainment in concrete so that the works can be finished on or before the schedule. This mandate is solved by high early strength cement and the usage of a low water/cement ratio. However, the above process results in a large amount of thermal and drying shrinkage, modulus of elasticity, and lower creep coefficients. Further, with a large amount of cement, concrete shows larger cracking behavior because of amplified thermal shrinkage and drying shrinkage. Therefore, high early strength concrete enhances the risk of cracking compared to moderate strength concrete. To decrease the effect of initial cracks and to repair the generated cracks in the concrete, several methods have been used in the industry. Self-healing bacterial concrete is one such method. Preliminary investigations have shown that using bacterial self-healing concrete helps us in increasing the mechanical properties of concrete along with healing the cracks up to a width of 0.3 mm. In this research, an effort is made to comprehend the effect of bacterial self-healing concrete on the fracture behavior of reinforced concrete beams. To understand this, several parameters such as beam deflection, load-carrying capacity, cracking pattern, energy absorption capacity, ductility factor, and ultimate moment carrying capacity, were checked with M25 grade concrete with fly ash and silica fume. Different parameters confirm that the load-carrying capacity of self-healing concrete increased up to 21% with a change in fracture behavior and deflection with a greater number of cracks and less width. Further ductility of beam increased up to 45%, and with a minimum of increased energy absorption of 100%. This shows that bacterial concrete is a sustainable alternative for the future construction industry as it extends the durability of the structure.