Construction of Water Pond Using Bioslurry-Induced Biocementation
Yang Yang, Jian Chu, Hanlong Liu, Liang Cheng
Abstract
This paper presents a methodology to construct a water pond in sand using bioslurry layer via the microbially induced carbonate precipitation (MICP) process. Bioslurry is calcium carbonate crystals containing high-urease active bacteria cells, allowing further microbially induced calcium carbonate precipitation when introducing cementation solutions (urea and calcium ions). With the effect of a top sand layer, the daily seepage rate of the water pond was dramatically reduced to 3 mm/day through four rounds of treatments with 1.6 M of cementation solution. In this way, a bioslurry-based waterproofing layer was formed for the construction of a water pond. Due to the bonding strength gained from calcium carbonate crystal precipitation, the flexural strength of bioslurry layer was in the range of 3.6–4.2 MPa. This is sufficient to support the hydrostatic pressure and avoid bending for water pond. With the low seepage rate and high flexural strength, the proposed bioslurry layer is a promising method for the construction of a fishpond in sand; other potential applications include stabilization of sand dunes and concrete healing.