Optimizing precipitation method of microbial carbonate precipitation on model recycled aggregate

Abstract

This paper improves the properties of recycled aggregate (RA) with the optimum precipitation methods by employing Sporosarcina pasteurii bacteria to induce microbial carbonate precipitation (MCP). To study the modification effect on different specimen surfaces, concrete cube specimens were prepared as model RAs. To optimize precipitation method, two influencing factors on precipitation, namely the calcium-source addition method and rotation treatment, were considered. An optimum precipitation method was proposed: RAs were dried, and submerged with precipitation culture media containing bacteria first; then the bacteria-saturated RAs were submerged into another precipitation culture media without bacteria, where the calcium-source solution was added in batches.