Experimental Study on the Aeolian Sand Solidification via MICP Technique

Abstract

This study solidifies the aeolian sand by microbial-induced carbonate precipitation (MICP) technique. The effects of cementation solution with different concentrations, particle size, and grouting batches are examined via the bender element, unconfined compressive test, and scanning electron microscope (SEM). The bender element results show that the wave speed of loose aeolian sand is 200 m/s; however, after solidification of the aeolian sand, the speed of P-wave is about 450-600 m/s and S-wave is about 350-500 m/s. Additionally, the unconfined compressive strength (UCS) results indicate that when the concentration of cementation solution is 0.75 mol/L, the UCS of biosolidified sand sample is the highest. Then, compared with the aeolian sand with original grade, the particles ranging from 0.1 to 0.4 mm have a better cementation effect. Moreover, the UCS of biosolidified sand samples increases along with the grouting batch. From the SEM images, it can be seen that when the grouting batch reaches to five times, the particles are almost completely covered by CaCO3 crystals compared with the three batches and four batches.