Effect of Water to Cement Ratio on Autogenous Shrinkage of Pavement Cement Concrete and Its Mechanism Analysis

Abstract

The autogenous shrinkage of pavement concrete with different water to cement ratios are measured in an experimental setup, and these samples’ gradation and pore structure characteristics are analyzed by a mercury intrusion method and an optical microscope with the Image Pro-Plus software package. The autogenous shrinkage model of pavement concrete with 0.38–0.44 water to cement ratio is established. The results of the shrinkage mechanism analysis show that pores with a diameter less than 100 nm play a vital role in autogenous shrinkage, varying the water supply volume only changes the number of capillary pores, and varying the cement volume changes the capillary number, the total porosity of the mixture, the average pore diameter, and the pore space factors.