Abstract
Triaxial compressive tests were carried out at different confining pressure and water content to understand the deformation mechanism of hardened cement paste. Results showed that stress did not decrease up to 10% strain, and macroscopic damage was not observed when tested under a certain confining pressure. This confining pressure differed depending on moisture content. Stepwise creep tests were conducted, and the slopes of the obtained differential stress-strain rate curves in a double logarithmic chart were around three, indicating that deformation was caused by dislocation creep. A sample saturated with sucrose solution exhibited more brittle behavior after the peak stress as compared to the behavior of the sample saturated with tap water. The results indicated that the deformation of cement paste was probably affected by dislocation, mechanical twinning, and pressure solution. Those mechanisms can affect cement paste and concrete deformation under low confining pressures.
