Assessing the spatial variability of the concrete by the rebound hammer test and compression test of drilled cores

The spatial variability of the mechanical properties of concrete is an important characteristic, which plays an important role in the stochastic analysis of the concrete structures, especially in the reliability analysis. Two categories of experiments named non-destructive testing (NDT) and destructive testing (DT) are used for the laboratory concrete beams. Rebound hammer techniques as NDT and compression tests of the core samples drilled from the concrete beams as destructive testing (DT) are utilized to assess the spatial variability of the mechanical properties of concrete, respectively. The strength values of concrete at different locations of concrete beams are estimated by the rebound measured data. The complete stress-strain curves of the cylindrical core specimens at ten test areas of concrete beams are obtained from the compression tests. The corresponding statistical results, including the mean values, the standard deviations (SDs), the coefficients of variation (CVs), the correlation lengths, and the probability density functions of the mechanical properties of concrete are obtained according to the statistical methods. (C) 2018 Elsevier Ltd. All rights reserved.