Feasibility assessment of newly isolated calcifying bacterial strains in self-healing concrete

Abstract

In the present study, rarely explored spore former (Bacillus safensis & Bacillus pumilus) and non-spore former
\n(Arthrobacter luteolus, Chryseomicrobium imtechense & Corynebacterium efficiens) alkaliphilic calcifying microbes
\nwere evaluated for their prolonged survival in cementitious environment. Extensive experimental program was
\ndesigned to examine mechanical, self-healing, microstructural modifications and durability of self-healing concrete
\n(SHC). Results of the experimental program endorsed the survival of all bacterial strains in the harsh
\nconcrete environment along-with improved mechanical response of matrix. Moreover, investigated strains were
\ncapable of precipitating copious amount of calcite having maximum of 0.8 mm average crack healing with 86 %
\nstrength recovery. Densification of microstructure was evident from the microstructural evaluation and pore
\nrefinement. SHC portrayed a significant resistance of 50 % and 20 % against Cl- penetration and sulphate attack.
\nConclusively, these strains have potential to impart sustainability in concrete structures by extending the
\nstructural life, subsiding repairs cost and conserving the natural resources.