Seawater based MICP cements two/one-phase cemented sand blocks

Abstract

The Sporosarcina pasteurii strains can grow and multiply in seawater medium and have certain urease activity. The two-phase and one-phase cementation methods can be used for the construction of ocean islands and reefs far away from the mainland in seawater seawater based MICP (Microbial-Induced Carbonate Precipitation). The compressive strength, carbonates content and porosity of sand blocks cemented by seawater based MICP with two-phase and one-phase methods are measured and compared. The results show that the strength and carbonates content of sand blocks with two-phase biocementation are greater than that of one-phase. The SEM images show that the principle of seawater based MICP cementing loose sand blocks is that carbonates particles grow between the sand particles, and them act as a bridge to bind the loose sand particles into a whole. The seawater based UPB of different pH can induce calcium carbonate deposition at different time. The seawater based UPB of different pH can be selected according to the actual project to reinforce the island reef sand foundation and prepare building materials under one-phase biocementation.