Investigation of Permeability of Dredging Sand Mixing Cement and Bentonite

The hydraulic conductivity of soilcrete specimens created from dredging sand mixing with cement and bentonite expects to be relatively low to apply as impermeable cores for embankments, dams, containment walls, and so on. Hydraulic conductivity of dredging sand samples taken in Dong Thap province mixed with a cement content of 300 kg/m³, various bentonite contents of 25, 50, 75, and 100 kg/m³, respectively, was conducted in the laboratory. The permeability tests followed the ASTM D5856 and D5084 standards for more than 3 months. The results indicate that: (1) The hydraulic conductivity of the dredging sand mixed with cement was lower 1000 times than that of the unmixed sand; (2) the hydraulic conductivity of the sand mixed with cement and bentonite was lower than that of the sand mixed with cement and slightly increases with increasing in bentonite contents; (3) the hydraulic conductivity of soilcrete decreases with increasing in curing times; (4) the hydraulic conductivity of soilcrete was identical with hydraulic gradients; (5) the hydraulic conductivity of soilcrete varied from 4.86 × 10^–9 m/s to 1 × 10^–10 m/s.