The use of microbially induced calcium carbonate precipitation to improve the strength of soils

Microbially induced calcite precipitation (MICP) is a process in which bacteria metabolise urea and calcium chloride to form a natural cement layer of calcium carbonate that binds soil particles together. The method has already been used in a large number of studies on a laboratory scale and also in the field to tackle a wide range of ge-otechnical problems. However, the great potential of this technique is countered by a large number of variables that can have a significant influence on the development of calcite precipitation. This article deals with the basic procedure of MICP and its implementation in the laboratory. In an experimental program, samples premixed with bacterial solution were subsequently cemented using different treatment steps. The specimens were then investigated in terms of their unconfined compressive strength. The results show the sensitivity of the method for different boundary conditions during sample preparation, but also the great potential of using MICP as a climate-friendly alternative for conventional techniques to improve soil strength.