Deep soil mixing method for the bio-cement by means of bender element test

Abstract

This article presented the effect of mixing patterns for the bio-cement in two different soils (Kaolin clay and Bangkok sand). Bio-cementation process initiated the crystal forms of calcium carbonate (CaCO3) to bind the soil particles. Soil samples were mixed with the solution containing 250 mM of CO (NH2)2, 250 mM of Ca2+ (by CaCl2) and 20% (v/v) of urease. In simulated deep mixing of Kaolin clay, the research found that blades used in solution mixing affected the strength development of Kaolin clay after bio-cementation. The Vs of 210 m s−1 was found in comb blade mixer. In simulated deep mixing of Bangkok sand, the research found that solution injecting method affected the Vs of Bangkok sand. The period drop and the period injecting methods provided better Vs results than the one time pouring and the continuous injecting methods.