<title>Near-field microwave reflection property analysis of concrete using open-ended rectangular waveguides at S- and X-band</title>

Abstract

Near-field nondestructive reflection property characterization of concrete based materials using open-ended rectangular waveguide probes is presented. The statistical distribution of multiple reflection property measurements are used as a tool to determine the water-to-cement (w/c) ratio as well as the coarse aggregate volumetric distributions in several concrete mixtures. These results may be used to determine the compressive strength of concrete. In this effort, concrete specimens with 0.50 w/c ratio were used. For these specimens sand-to-cement (s/c) ratio of 1.0 was used along with coarse aggregate-to-cement (ca/c) ratios of 1.0, 1.5, and 2.0, respectively. The microwave reflection coefficient of these specimens were measured at x-band (10 GHz) and S-band (3 GHz) using an HP8510 vector network analyzer. The results of these measurements, from the point of view of their probability distribution functions are presented, in addition to discussions regarding their implementation for nondestructive characterization of concrete based materials.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.