Study of the Gap Parameters of Cement Mortar Specimens Based on X-ray Tomography

Concrete is one of the most widely used structural materials next to steel. This justifies a detailed study of the material structure to understand the influence of the production parameters on the properties of the concrete. The pore structure of concretes has a major influence on their practical use, as it impacts their resistance to environmental degradation (e.g., frost resistance). In the present study, I have investigated concrete and cement mortar specimens with different water-cement ratios using micro-CT (or micro X-ray tomography) to determine the pore structure and the pore gap parameters of the specimens. It can be concluded that with an increasing water-cement ratio the overall porosity of the samples and the number of large pores (1 mm3) show a decreasing trend, in contrast, the gap parameter shows an enhancing trend. It can also be concluded that any pore-forming additives cause significant changes in the structure.