Pavement Analysis and Design for Hydrated Cement Treated Crushed Rock Base (HCTCRB) Pavements

Abstract

Hydrated Cement Treated Crushed Rock Base (HCTCRB) is a cement modified basecourse material which the mixture of a standard crushed rock base and cement is disturbed after hydration. The unique production process for HCTCRB is different from that of a common cement-treated base to prevent cementitious bonding in order to maintain the unbound material characteristics with an improvement in material engineering properties. This paper presents the mechanistic-empirical pavement analysis and design for flexible pavements containing HCTCRB basecourse. The resilient modulus presenting the stress dependency behaviour of HCTCRB derived from the repeated load triaxial tests were used as one of the input for the analysis and design. Pavement analyses in this study covered various states of materials i.e., linearity or non-linearity, and isotropy or anisotropy of pavement materials. A three - dimensional finite element analysis of pavement structure was also carried out. The conventional pavement analysis in Australia by Circly software, using the anisotropic and quasi-non-linearity technique, is still deemed reliable in comparison with the various approaches examined in this study. However, there remains a concern regarding the reliability of the single input value of the resilient modulus derived from the resilient modulus tests. The average resilient modulus from the test results appeared to be too high for an effective analysis to be undertaken. Based on the stress-dependent analyses conducted and concerned with the thickness range of the basecourse layer, a typical value for the resilient modulus of HCTCRB was determined.