Microstructural characteristics and nano-modification of interfacial transition zone in concrete: A review

Abstract

The interfacial transition zone (ITZ) has long been considered as a zone of weakness in concrete. Many scholars have carried out relatively scattered tentative explorations to improve the performance of ITZ. The application of nanomaterials to enhance ITZ in concrete is a promising research. In order to further study the basic principles and practical applications of this field, it is urgent to systematically sort out the existing results. In this study, the nano-modification of ITZ in concrete is systematically reviewed and summarized. First, this study reviews the microscopic characterization of ITZ, including hydration products, porosity, and microhardness. Then, the influence of nanomaterials on ITZ is reviewed from the view of the above three aspects. Finally, the method and mechanism of the ITZ modified by nanomaterials were preliminarily clarified, which provided theoretical and empirical data support for the team's next experimental work. A large number of research results show that nanomaterials improve the mechanical properties and microstructure of the ITZ, thus enhancing the mechanical properties and durability of concrete. The results of this article will provide source materials for the development of this field, a broader research basis for peer research, and a basis for further development of green engineering materials.