Biocementation for Sand Using an Eggshell as Calcium Source

A method to generate biocementation in sand using the microbially induced carbonate precipitation (MICP) process and calcium source produced from eggshell is presented in this paper. Instead of using calcium chloride or other calcium salts, soluble calcium was produced by mixing eggshell with vinegar and used for the MICP process. The compressive strength and permeability of sand treated using this method were measured using unconfined compression and permeability tests. A comparative study between sand samples treated using calcium produced from eggshell and those using calcium chloride with the same concentration of calcium was carried out. The study shows that the effect of the MICP process using calcium produced from eggshell is just as good as that using calcium chloride. The optimum ratio of eggshell and vinegar for the MICP process was established. (C) 2016 American Society of Civil Engineers.