The effect of coarse to fine aggregate ratio on drying shrinkage of roller compacted concrete pavement in different curing conditions

Drying shrinkage is an inevitable phenomenon that leads to cracks and eventually remarkable volume changes in hardened concrete. In this study, the drying shrinkage strain behavior of roller compacted concrete pavements (RCCPs) in two different curing conditions was investigated. The variables of RCCPs were coarse to fine aggregate (C/F) ratios of 0.7, 1, 1.2 and 1.5 in two cement dosages of 12% and 15%. Vebe tests of the fresh RCCP as well as the compressive, splitting tensile and flexural tensile strengths of the hardened RCCPs were also performed. The test results indicate that by increasing cement content from 12% to 15%, the drying shrinkage strain increased in both cured and non-cured conditions. Generally, the drying shrinkage strain was significantly increased when the C/F ratio was lower than 1.0. It is highly recommended that C/F aggregate ratio is used in the range of 1.0 to 1.2 in the mixture of RCCP.