A 2D rapid quantitative method for wetting and drying process in cementitious materials based on X-ray radiography

Abstract

The infiltration of water is a crucial factor in the degradation of the durability of concrete structures. It is important to conduct wetting and drying experiments to validate the water transport performance of construction materials during their service life, with precise measurement of both the process and the outcomes being essential. This study proposes a 2D quantitative detection method based on X-ray Radiography to determine the distribution of moisture content. This technique enhances conventional X-ray Radiography methods by utilizing a higher tube voltage to mitigate the impact of beam-hardening effects, as explained by the monochromatic index introduced here, and employs a coefficient matrix for correcting field non-uniformity and a spatial positioning algorithm to rectify discrepancies among multiple measurements. This method offers several benefits due to its capacity to provide in-time, accurate, non-contact, and cost-efficient quantitative results without any contrast agent while maintaining appropriate spatial resolution. The feasibility of this method is verified through a wetting and drying experiment taking cement paste material as an example. When compared with the gravimetric method, experimental results show that the relative error of moisture content obtained from this method is less than 5.76 %.