Mechanical performance of strain-hardening cementitious composites (SHCC) with bacterial addition

Incorporation of bacteria can realize self-healing and enhance strength of concrete, which has been drawn extensive attention in past decades. The studies focused on the properties of fiber reinforced concrete with bacterial addition are still very limited. In this paper, mechanical performance of strain hardening cementitious composites (SHCC) with directly adding vegetative bacterial cells was investigated. The experimental results revealed that the compressive, first cracking, and tensile strength of SHCCs was increased due to the addition of bacteria, while the tensile strain capacity tended to decline. At micro-scale level, the matrix containing bacteria has relative higher fracture toughness to that of reference mix. Interestingly, the bacteria notably lowered chemical bond between PVA fiber and its surrounding hydrates; on the other hand, the frictional bond was enhanced. The findings in this study can provide a reference for modifying the surface of hydrophilic fibers.