Optimization of process parameters by Taguchi method for maximizing strength and durability of bio concrete

The tremendous growth in the construction industry has led to a shortage of natural water and aggregates for concrete. It is an acute problem faced by the construction industry in recent years. To overcome this problem, attention is focused on finding alternatives to provide an amicable solution to this problem. Using industrial waste as coarse aggregate and treated wastewater for mixing is a great opportunity. In the present research, the microbiologically induced calcium carbonate precipitation technique is adopted by using steel slag as coarse aggregate, different types of wastewaters for mixing, and isolated bacteria to develop bio-concrete with maximum strength and durability. Optimum conditions of the parameters are determined using the Taguchi approach L9 (3(3)) orthogonal array layout. Analysis of means indicates that optimum conditions for maximum compressive strength and durability of bio-concrete are reported as 50% steel slag aggregate replacement with natural aggregate, 75 ml bacterial solution with treated wastewater through construction wetland. Analysis of variance indicates that steel slag aggregate has made the greatest impact on the compressive strength and durability of bio-concrete followed by mixing water and bacterial solution. Furthermore, SEM and XRD results show the compact microstructure of concrete due to the microbiological precipitation of calcium carbonate by bacteria.