IJSRSET1702 | Published 16 March 2019 | January-February-2019 [ 5 (6) : 424-428 ] National Conference on 'Advances in Engineering, Technology and Applied Sciences' - NCAETAS-2019 © 2019 IJSRSET | Volume 5 | Issue 6 | Print ISSN : 2395-1990 | Online ISSN : 2394-4099 424 An Investigation on Bacterial Concrete Shreya Gadhave, Pritam Dandekar, Harshal Pawankar, Atul Kurzekar Civil Engineering Department, Yashwantrao Chavan College of Engineering, Nagpur, Maharashtra, India ABSTRACT Cracking in concrete is the main concern throughout the structures because it causes loss of strength with time. Hence a special type of environmental free solution is to be made for maintenance purpose. Therefore a bacterial concrete is prepared. However, the drawback of this material is that it easily cracks due to its low tensile strength, & due to temperature expansion, contraction, whereas the creep & shrinkage also produce cracks. While bigger cracks deteriorate structural integrity, also hair-line cracks may result in durability problem. In this study we will discuss about the self-healing process of concrete is process by which the cracks obtained in the body of concrete get repaired by itself or it required some external help to complete self healing activity. The bacterial species called Bacillus subtilis for increasing the strength of concrete and decreasing the porosity at 28 Days. Though these species are eco-friendly and does not cause any harm to human and use for improving the resistance of concrete when exposed to alkaline, sulfate and freeze-thaw environments. This paper mainly comprises of activation of bacteria and focuses on strength of bacteria concrete with normal concrete and also filling of cracks. Keywords: Bacterial Concrete, Bacillus Subtilis, Self Healing, Compressive Strength. I. INTRODUCTION Cracks often occur in concrete because of low compressive strength and flexural strength after application of load on a structure. Water or aggressive material may seek in the concrete through cracks. Inspecting and then repairing these cracks are time consuming and costly. So we have come up with a new concept of crack healing concrete by releasing healing agents inside the concrete when cracks appear. Ghosh et.al. investigated seven different bacterial concentration of shewanella species(10-10^7cells/ml) and obtained optimal bacterial concentration to be 10^5cells/ml with corresponding 25% increase in compressive strength. In these research paper, We have discussed an environmental friendly self-healing concrete technique. In previous research carried out, Bacillus sphauricus bacteria were used to precipitate calcium carbonate. In this, the bacterial cell get coated with a layer of calcium carbonate the aim of our research work is to use CaCO3 precipitated by the Bacillus subtilis to heal the crack in concrete. Cracks often occur in concrete because of the low tensile strength of this material. Rapid crack healing is necessary since it is easier for aggressive substances to ingress into concrete through cracks than through the concrete matrix. It is known that it is costly to inspect, monitored repair cracks. Moreover, some of the repair methods currently used is not so sustainable [Neville 1996]. Therefore, it would be desirable if concrete cracks could be healed autonomously by releasing healing agents inside the matrix when cracks appear. In this