Analysis of cementitious matrices self-healing with bacillus bacteria

Abstract

Bacterial solutions have been studied to promote self-healing of cementitious matrices, however, the concentration of this solutions varied between studies. Consequently, the objective of this study was to evaluate the self-healing potential of different concentrations of Bacillus subtilis AP91 encapsulated in expanded perlite (EP). Visual examination and capillary absorption of water was measured over time. Test samples were also subjected to strength resistance tests. The physiochemical properties of EP and his distribution on the matrix was evaluated. There was no observable trend in the effect of solution concentration on the width of crack healed. However, concentration affected the quantity and length of the fissures healed. Capillary absorption decreased as fissures were healed while no significant changes were measured in strength resistance regardless of the concentration. Results indicated that EP provided suitable encapsulation to the bacterial solution and there is an adequate distribution of the capsules in the cementitious matrix.

Evaluation of concrete self-healing by encapsulated sodium metasilicate in perlite and expanded clay

“…Consequently, in this study, if a crack appeared along a region of smaller particles, there was a chance that the substitute aggregate did not fracture and sodium metasilicate was not exposed to humidity. Those results of cicatrization occurrence being affected by the crack area, the surface characteristics, and the healing product availability were also pointed out by Pacheco et al [34] and Muller et al [47]. Overall, EP substitution achieved between 57.58% and 100% healing of the crack while EC substitution achieved between 12.63% and 90% healing.…”