Study on Self-healing Properties of Bacteria Based Cement Mortar with Eggshell Powder and Jute Fibre

The work explores the experimental investigation of Bacillus paramycoides bacteria with the concentration of 10⁵ cells/ml in cement mortar cubes. Eggshell powder (ESP) was utilized as a cement replacement in three different percentages of 5, 10 and 15%, and jute fibre was used with a constant dose of 0.5% in volume fractions to evaluate the strength and durability properties of cement mortar. In this work, ESP was used as a nutrient source and jute fibre as a carrier material to intensify the healing efficiency of bacteria concrete. Eight mixtures were prepared and divided into three series: control (no bacteria, ESP and fibre), with and without bacteria including the eggshell shell powder and fibre. For all mixtures, mortar cube specimens were prepared for 7, 14 and 28 days to determine the compressive strength (CS) and healing efficiency. Durability properties such as sorptivity were studied for uncracked and pre-cracked specimens at 28 days under full-wet curing. Based on the test results, notable strength improvement and rate of crack healing were observed for all fibrous mixtures with bacteria and ESP than control mixes. Microstructure study such as Scanning Electron Microscopic (SEM) analysis and X-ray diffraction (XRD) analysis was investigated to evaluate the elements present in different mixtures.