Volume 6, Issue 9 (October 2009)
Using X-Ray Absorption to Assess Moisture Movement in Cement-Based Materials
This paper discusses the use of x-ray absorption as a technique for measuring fluid transport in cementitious systems. First, the paper describes how a material’s x-ray attenuation spectrum can be combined with composite modeling concepts to determine the extent of moisture movement (wetting or drying) that can be measured in cementitious systems. Second, the paper discusses the influence of beam power (voltage and current) and camera integration time on the variation in the measured x-ray intensity. Third, the paper discusses two devices for measuring the transmitted x-ray intensity (camera and detector) to describe differences in their measurements and resolution. Finally, a demonstration is provided to show how x-ray absorption can be used to detect moisture ingress and determine the transport properties of the material under evaluation.