Evaluation of Mechanical Parameters of Bacterial Concrete

Abstract

Received: 25 July 2019 Accepted: 1 October 2019 Conventional concrete is prone to cracking under tensile load, despite its good compressive strength. Recently, biological agents have been applied to heal the cracks in concrete, making concrete structures more serviceable. This paper mainly attempts to evaluate the mechanical properties of bacteria-based self-healing concrete. Two bacteria were selected as the bioagents in concrete, namely, Bacillus subtilis and Bacillus halodurans. The concentration of the bioagents were set to 10~10 cell/mL in water. Then, the two bacteria were applied to cracked concrete to cure the cracks. After curing for several days, the bacteria-based self-healing concrete was subjected to compressive and flexural tests to estimate its mechanical parameters. The results show that the self-healing concretes cured for 14d and 28d had a 7% and 18% higher compressive strength than conventional concrete, respectively; the self-healing concretes cured for 14d and 28d had a 11% and 28% higher flexural strength than the conventional concrete, respectively. Thus, the bioagents could effectively heal the surface cracks on concrete, and make the concrete imperviable.