Dynamic Characterization of Sand Stabilized with Cement and RHA and Reinforced with Polypropylene Fiber

Abstract

This paper introduces rice husk ash (RHA) as an acceptable replacement for cement in the chemical stabilization of sand, with economic and environmental benefits. Unconfined compression strength (UCS), bender element (BE), and cyclic triaxial (CT) tests were conducted on various samples containing different contents of cement, RHA, and polypropylene fibers. The test results were then used to develop new relationships for the dynamic characterization of stabilized sand in terms of damping, shear modulus, and degradation index. The accuracy of the proposed predictive models was subsequently validated using two independent CT tests carried out on arbitrary samples containing stabilizers in the applicable range of the study. Also, the effects of the relevant parameters on the degradation index were investigated using a three-dimensional graphical parametric study. Sensitivity analysis was conducted to show which parameters had the greatest and least effects on the dynamic properties of stabilized and reinforced samples. To investigate the mechanisms behind the reactions, microstructural investigations were used. An application of the proposed relationships in the dynamic design of pile-supported foundations is presented.