Study on mechanical properties of the interfacial transition zone in carbon nanofiber-reinforced cement mortar based on the PeakForce tapping mode of atomic force microscope

Abstract

In this study, the PeakForce quantitative Nanoscale Mechanical Characterization (PF-QNM) mode was used to explore the micro-zone mechanical properties of the interfacial transition zone (ITZ) in carbon nanofiber (CNF)-reinforced cement mortar. It was found that adding CNFs increased the Young’s modulus of neat cement paste and cement mortar specimens by 15.5% and 36.7%, respectively. The morphology of the interface in a mortar specimen under the PF-QNM mode showed the close embedding of fine aggregates in set cement, which may facilitate force transmission and energy dissipation. The filling and bridging effects of CNFs may increase the Young’s modulus of set cement. The flexural strengths and Young’s modulus of specimens were measured by macro-mechanical tests; the results of which were found to be consistent with the results of micro-zone mechanical property tests. The convenience and accuracy of the test results of the PF-QNM mode were found to be promising.