MXene Nanosheets Magic: Unveiling the Dual Effect of Strength and Ductility Enhancement in Strain Hardening Cementitious Composites

The aim of this study was to modify strain hardening cementitious composite (SHCC) using MXene nanosheets to further enhance its strength and ductility. The results showed that the addition of 0.03 wt% MXene nanosheets increased the compressive strength and tensile strain of SHCC by 18.04% and 88.18%, respectively. The mechanism of MXene nanosheets in improving the mechanical properties of SHCC was revealed by single fiber pullout test, micromechanical analysis, microstructure analysis and finite element analysis. Firstly, MXene nanosheets fill the pores inside the matrix, reduce the porosity of the matrix, disperse the stress, and inhibit the crack propagation, thus improving the compressive properties of SHCC. Secondly, when MXene nanosheets adhered to the fiber surface, they modified the interfacial properties between the fiber and the matrix, preventing fiber pullout and consequently improving the tensile ductility of SHCC.