Nano-indentation experiment for determining mechanical properties of typical cement phases at nano/micro-scale

Abstract

Nano-indentation experiments are carried out on two cement pastes in order to get mechanical properties of cement pastes. For the comparison of initial cement paste, metakaolin as a valuable admixture for concrete/cement applications is added, considered to increase the reactivity of pozzolans. Statistical analysis on a number of indent points can be traced back to a medium modulus of elasticity. The averaged elastic moduli of typical phases in cement pastes are thus determined. Young's moduli of CH phases is about 44.7GPa by nano-indentation experiment, which are close to the previous simulation values and other references. Besides, Young's moduli of Calcite and clinker averaged by nano-indentation experiment are 86.695GPa and 102.230GPa, which are separately in relative good agreement with simulation values of 84.549GPa by Jia and 85.41-145.56GPa (porosity: 10%) by Arar. A systematic approach is developed to validate and to assess the elastic parameters associated with each phase. The P-h curves of the simulation and experiment are compared to conclude on the feasibility of the methodology.