Study on synthesizing MgAl-LDH in the concrete crack zone to enhance microbial mineralization capacity

Abstract

The microbial self-healing technology for ocean concrete cracks encountered two challenges: microbial growth was difficult, and eroding ions posed a threat to concrete durability. In this study, microbial survival and mineralization performance were enhanced by generating MgAl-Layered Double Hydroxide (MgAl-LDH) in a simulated solution. Additionally, the formation of MgAl-LDH was found to effectively immobilize eroding ions, thereby improving the durability of concrete. The synthesis of MgAl-LDH was achieved by the addition of magnesium and aluminum sources in the experiment. The results demonstrated that the unique interlayer structure of MgAl-LDH could adsorb SO42− and Cl−, reducing the concentration of eroding ions in the solution. Simultaneously, a significant amount of OH− was consumed during the formation of MgAl-LDH, leading to a reduction in the pH. In the lower pH environment, there was a significant increase in both the survival quantity of microorganisms and the quantity of mineralization products. The research provided a new idea into microbial self-healing of marine concrete cracks.