Observation of recycled aggregate structure using X-ray CT

The use of low quality recycled aggregates in concrete reduces performance and increases variation. Therefore, it is important to examine the performance and safety of concrete using low quality recycled aggregates from a variety of perspectives. This study applied X-ray CT and image analysis to examine the structure of recycled aggregates in order to explore how X-ray CT may be applied to recycled aggregate concrete. It was found that recycled aggregates from different sources showed widely varying X-ray CT absorption values, which makes it difficult to carry out further analyses unless there are clear differences in the material phases. However, it is possible to estimate the amount of residual mortar through segmentation between the solid and void phases.