AN ESTIMATION OF AGGREGATE LAYOUT IN A CONCRETE CYLINDRICAL SPECIMEN FROM X-RAY TOMOGRAPHY IMAGES

Abstract

In this study, the aggregate's and void's location, size and shape is determined as a constructive information of concrete from X-ray tomography. To extract aggregate and void data from the image, thresholding approach is generally adopted. However, in aggregate's process, since the power of X-ray is dropping during the penetration, the CT number should be compensated by a function related to the distance from the edge. For the noise reduction, a modified median filter is applied. In order to investgate the applicability of this process, the size of every aggregate and void is computed from 13 slice and 2D images. About aggregates, a virtual sieve analysis is conducted. Comparing with the real test, the virtual test tends to estimate the size to be smaller than the real test. About voids, a virtual air content test is conducted. Comparing with the real test, the virtual test tends to estimate the content to be smaller than the real test.