Application of Non-Destructive Testing for Measurement of Strength Development of Biocemented Sand

Soil biocementation is the new technology using biological process to initiate the crystal forms of carbonates to bind the soil particles resulting in soil mechanical improvement. This research examines the feasibility of microorganisms capable of hydrolyzing ammonia with production of carbonate collected from natural soil. The biocement was prepared by a mixture of calcium salt, urea, and microbial suspension collected from natural water samples. The urease activity was measured by the concentration of NH4+ in solution. The physico-chemical properties including the effects of Ca2+ concentrations, soil pH and crystal forming shapes were studied. The strength development of biocemented soil samples was measured by non-destructive test using shear wave velocity method. Formation of calcite layer on sand surface could be useful for the stabilization of the sand or earth structures.