Recent advances and insights in nanoindentation technique in the characterization of cement-based materials

The mechanical properties, deformation performance, and failure modes of cement-based materials (CBMs) largely depend on their compositions and structural characteristics at the micro/nano scales. The nanoindentation technique, as a cutting-edge testing technology, can provide the nanomechanical properties and deformation characteristics of various phases in CBMs as well as the interfacial transition zone (ITZ) characteristics. It could greatly promote the understanding of the microstructure and properties of CBMs and also serve as the basic information for the numerical simulation of CBMs from micro/nano scales. This paper systematically introduces the basic principles of nanoindentation, preparation methods of CBM test samples, selection criteria of test regimes, and processing methods of test data. Meanwhile, the research status and related achievements of nanoindentation in CBMs science and research are reviewed, including nanomechanical properties of various phases of CBMs, creep behavior, the characteristics of ITZ, and the application in numerical simulation.