Sandy Soil Improvement Using MICP-Based Urease Enzymatic Acceleration Method Monitored by Real-Time System

This paper aims at monitoring the improvement of sandy soil properties with biocementation through microbially induced calcite precipitation (MICP) method reaction accelerations by self-developed soybean urease enzymes. In this study, concentration calcium ions (Ca2+ as CaCl2) is varied 50, 100, 250, and 500 mM to determine an optimum shear strength. The enzymes 20% volume (v/v) are used accelerate MICP finish within 7 days. Based on real-time bender element system direct tests, Ca2+ found 250 mM. However, a detrimental effect occurs in case high CaCl2 (500 mM) because solution acidification from Cl− concentration. condition lowers CaCO3 causing reduction process. At equivalent modulus, time MICP-based sand acceleration about 10 times faster than that without. Using spectrophotometer pH meter, ammonification rate biocemented for 3 days relatively higher those without 40 analyses scanning electron microscopy (SEM) X-ray diffraction (XRD) confirm not only occurrence binding particles together but also physical strengths samples enzymatic method. These results introduce option improvement.