Pore and Solid Characterizations of Interfacial Transition Zone of Mortar Using Microcomputed Tomography Images

The interfacial transition zone (ITZ) in concrete is known as the weakest link of the material, and significantly affects the properties of concrete. This study aims to investigate the actual microstructure of the ITZ using microcomputed tomography (micro-CT) in three dimensions (3D). For this purpose, high-resolution synchrotron micro-CT images of materials are used to visualize and examine the 3D ITZ of cement-based specimens. A set of mortar specimens with different water-cement (w/c) ratios as well as different aggregate types and sizes were prepared and compared to investigate the effect of each condition on the characteristics of the ITZ. The microstructural characteristics of the pores and the solid structures of the ITZ are characterized based on the information of grayscale images. The obtained results show the effective investigation on the pore and solid characteristics of the ITZ microstructure by using 3D nondestructive micro-CT; this approach is useful for further detailed investigation of the ITZ.

Automated summary

The study utilized three-dimensional micro-CT to investigate the interfacial transition zone (ITZ) in concrete, revealing that the pore and solid characteristics of ITZ can effectively be examined using this method.