Monitoring macro voids in mortar by X-ray computed tomography

In this study, X-ray computed tomography (CT) was shown to be a capable technique to quantify the evolution of macro voids and to monitor the strength development of mortar specimens. Two-dimensional image analysis was utilized to extract quantitative information from the X-ray CT data. In particular, monitoring and quantifying macro voids were of interest; thus nondestructive X-ray measurements were conducted on the same mortar specimen at different days. X-ray attenuations were then transformed into CT numbers, which was actually a map of linear attenuation coefficients in terms of Hounsfield Units; this map can be presented as a two-dimensional image. Analyses performed on these images revealed that the porosity of the mortar specimen reduced from 3.94% at the beginning to 3.06% at the end of the monitoring period.