Quantification of the residual mortar's distribution and wrapping degree in recycled concrete aggregate based on 3-D reconstruction technology

Abstract

X-ray computed tomography (X-ray CT) and spherical harmonics (SH) reconstruction technology were combined to quantify the content, distribution and wrapping degree of residual mortar in the recycled concrete aggregate (RCA). The RCA was submerged in 30 wt% CsCl solution, and scanned by using X-ray CT to determine its surface profile coordinates. The RCA’ morphology and its original aggregate were reconstructed by using SH reconstruction technology to determine the content, distribution and wrapping degree of residual mortar. The optimal reconstruction parameters were analyzed and the proposed method was compared with the methanol salicylate solution test. The results indicate that the optimal number of reconstructed sample points by SH function was 260 points at each angle. The error between the residual mortar’s content obtained by the proposed method and the methanol salicylate solution test was <5 %. The residual mortar’s content was not always consistent with its distribution and wrapping degree.