IDENTIFICATION OF MECHANICAL PROPERTIES IN SAND IMPROVED BY CALCIUM CARBONATE PRECIPITATED

Abstract

  A series of drained triaxial tests was performed to clarify the effects of calcium carbonate precipitation on mechanical properties of sand. SEM-EDX was also utilized to examine the quality and quantity of the precipitated, revealing that calcium carbonate is the only mineral precipitated onto grain surfaces. Well-controlled triaxial test results show us that calcium carbonate precipitated within grain aggregate clearly augments Young's modulus and shear strength, and those magnitudes increase with the amount of the precipitated. This augmentation is attributed to increase of surface roughness (i.e., friction), and of positive dilatancy. The test results also demonstrate that intergrain adhesion mediated by the precipitation exerts influence significantly on the elastic deformation, but little on the strength.