Experimental Investigation and Numerical Modeling of Short-Term Mechanical and Creep Properties of Cement Mortar

This study conducts several laboratory tests (triaxial compression, cycle loading, and cycle loading creep tests) to explore the degradation mechanism of mechanical properties of cement mortar. The results revealed that cement mortar exhibits brittleness characteristics under low confining pressure, whereas under high confining pressure, ductility deformation occurs. The failure strength of cement mortar under the triaxial cyclic loading creep test is 85.99% of the one in the triaxial compression test and 88.52% in the triaxial cyclic loading test. With the increasing confining pressure, cement mortar samples show tensile failure, local shear failure, and diffusion compaction ductile failure. Based on the experimental results, a constitutive model is proposed to describe the brittle-ductile transition, fatigue effect, and stress corrosion behavior of cement mortar. The model parameters can be determined directly or indirectly. Finally, the numerical simulation and experimental data are compared to confirm that the model could accurately represent the mechanical behavior of cement mortar.