Effect of Bacillus subtilis on mechanical and self-healing properties in mortar with different crack widths and curing conditions

Abstract

This research aimed to investigate the effectiveness of Bacillus subtilis (B. subtilis) in self-healing cracks in concrete and enhancing concrete strength through microbial induced calcium carbonate precipitation (MICP). The study evaluated the ability of the mortar to cover cracks within 28 days, taking into account the width of the crack, and observed the recovery of strength after self-healing. The use of microencapsulated endospores of B. subtilis was also examined for its impact on the strength of concrete. The compressive, splitting tensile, and flexural strengths of normal mortar were compared to those of biological mortar, and it was found that biological mortar had a higher strength capacity. Microstructure analysis using SEM and EDS showed that bacterial growth increased calcium production, contributing to the improved mechanical properties of the bio-mortar.

Effects of bacterial consortium enhanced recycled coarse aggregates on self‐healing concrete immobilized with Bacillus megaterium MTCC 1684 and Bacillus subtilis NCIM 2193

“…The researchers have been interested in a technique called microbially induced calcite precipitation (MICP) to heal concrete cracks because it involves a particular bacterial metabolic process to produce calcium carbonate precipitation. [10][11][12][13][14][15][16][17][18] According to previous research, different MICP processes depend mostly on microbial respiration and urea's enzymatic hydrolysis which causes denitrification and precipitation by the anaerobic bacteria. Some researchers have also applied enzymatic precipitation of carbonates and bio-inspired heavy immobilization for supplementing the elemental sources to the microbes for calcite precipitation.…”

Production of Self-Healing Mortar Using Bacterial Spores Encapsulated With Jute Fibre

“…Owing to the bridging behaviour in concrete and mortar, the fibres significantly restrict crack widths [8]. This attribute of fibres is crucial, especially for producing self-healing bacterial concrete, because bacteria offer a more effective and faster treatment of crack widths [9,10]. The working mechanism of the selfhealing bacterial concrete with jute fibre is shown in Figure 1.…”