Comparative performance of different bacteria immobilized in natural fibers for self-healing in concrete

By Momina Rauf, W. Khaliq, R. A. Khushnood, I. Ahmed. 2020

179 citations recorded by the source corpus.

Abstract Carrier compounds besides the type of bacteria for microbial induced calcite precipitation are equally important in self-healing concrete. This study investigates the potential utilization of natural fibers namely, coir, flax, and jute fibers to carry bacterial spores for self-healing in concrete. The comparison is drawn for introducing calcite precipitation bacteria namely Bacillus subtilis KCTC-3135T, Bacillus cohnii NCCP-666, and Bacillus sphaericus NCCP-313 in concrete along with calcium lactate pentahydrate and urea as organic nutrients. The findings from visual, microstructural, and mechanical properties of self-healing concrete suggest that natural fibers were capable of substantial immobilization potential for bacterial spores. Flax fibers provided better protection to bacteria with improved crack-healing and regain in compressive strength, whereas coir fibers resulted in higher compressive strength. It is also observed that B. sphaericus NCCP-313 precipitated more calcium carbonate as a healing product with uniform healing in the entire length of cracks in concrete. Consequently, approximately 75–85% and 60–65% healing rates were attained by fiber immobilized bacteria in 7 days and 28 days pre-cracked specimens, respectively.

Subfields: Civil and Structural Engineering, Environmental Engineering

View Paper: https://www.semanticscholar.org/paper/62af0781686e1280dbec3e31e5bd0e98139ad15c