Production of Self-healing Concrete using Gum Arabic for Immobilizing of Bacterial Spores on Sand

Abstract

This paper studies the feasibility of producing self-healing concrete by immobilization of bacteria on the sand. In this study, the Gum Arabic (Acacia Senegal) was used to immobilize bacterial spores and its nutrient (Calcium lactate) on sand surface as a novel technique. Due to its availability and environment-friendly character, Bacillus subtilis bacteria have been selected and prepared. To achieve the aim of this study, three concrete mixes were made with 10%, 5%, and 2.5% of gum-capsulated sand with bacteria. The ability of self-healing of cracks was monitored using stereomicroscope and digital image camera. The experiments have shown that the proposed technique is efficient in healing of cracks without impairing the prisms' strength for mixes with 2.5% and 5% of gum-capsulated sand with bacteria. The results give a proof-of-concept to use Gum Arabic as an adhesion to immoblize the bacteria and its nutrient on sand to produce self-healing concrete.