Study of the durability of biocementation treatment applied to a real slope in Portugal

Biocementation treatment was adopted to treat a Portuguese sandy slope to prevent erosion caused by water flow. The calcium carbonate content was measured in small samples collected at the surface of the treated area in monitoring campaigns performed periodically after the treatment, to investigate durability. Complementary laboratorial tests were performed in the laboratory, in which samples of the same soil were prepared mimicking the treatment applied. These samples were subjected to 10 wetting-drying cycles to study durability, being measured the permeability and shear strength before and after the wetting-drying cycles. Although the treatment was heterogeneous in the area, both for the slope and in the laboratory tests, the results indicate that the amount of the biocement in the soil remained after these cycles, not affecting permeability and strength. Durability was observed in these tests, although more time and cycles are necessary to evaluate this parameter.