Microstructural and Cantabro loss studies on self-healing concrete with crushed stone sand, Bacillus subtilis bacteria and calcium lactate

In this paper, effect of Bacillus subtilis and crushed stone sand on Cantabro loss of bacterial concrete was investigated. River sand along with crushed stone sand were partially replaced with fine aggregate in preparation of M40 grade concrete. Bacillus subtilis bacteria solution comprised of calcium lactate was added in dosage of 5, 10 and 15% by weight of cement in all mixes. Strength and abrasion resistance of these mixes were studied at 3, 7, 28, and 90 days of curing. Scanning electronic microscopy and X-Ray Diffraction studies indicate the presence of calcium carbonate in bacterial concrete mixes. Abrasion resistance in terms of Cantabro loss is strongly influenced by flexural strength of concrete for both river sand and crushed stone sand mixes. An empirical equation is proposed relating strength of bacterial concrete and Cantabro loss in the form C L = A ln ( f c ) + B .