Use of Bionanocementation as a Technique in Increasing Resistance of Sandy Soil

With the increase in population and infrastructure, the search for areas for occupation has increased significantly. Therefore, there is also an increase in the environmental impacts associated with the bad use of the soil, thus making these soils need an improvement for their use. Soil improvement techniques used involve the addition of mechanical energy and/or synthetic materials. However, the bionanocementation technique has the purpose of improving the mechanical properties in a sustainable way. Biocementation is the formation of calcium carbonate that binds the soil particles by microorganisms metabolism. It only occurs when the microorganisms have a source of calcium and urea and the potential for biocementation. The objective of this work was evaluate the increase in mechanical strength, through the technique of bionanocementation, in sandy soil with different concentrations of calcium (20, 30 and 40 g/L). Calcium substrate was supplied at nano and micro scale. Four different treatments were performed in the experiment: SN−B; SN+B; CN−B and CN+B. Biochemical test of urease production, CO2 evolution test, compression strength test and MEV and EDS were performed. During the study, we observed that the product at nano scale was already in CaCO3, making the treatments with nutrient medium CN did not obtain good results. The CPs with nutrient medium SN stood out in the trials, as well as the treatments that had no bioaumentation. In addition, the results with higher concentration (40 g/L) stood out.