A feasibility study on the quality inspection method of asphalt pavement using x-ray CT

The pavement guideline in Japan has designated relative compaction, gradation, and bitumen content as inspection items. This study proposes the CT-value as a new quality evaluation index to examine these items. We conducted an X-ray scanning test using five specimens of a dense-graded asphalt mixture with different bitumen content. The image data processing device computed the CT-values. We then calculated three threshold values divided into the void, binder, fine aggregate, and coarse aggregate, the slice average CT-value of the specimen, and four segments based on the CT-value data. We identified the trend of the threshold values, and the average slice and segment CT-values of the asphalt mixtures with different bitumen content. In addition, we examined the relation between these inspection items and the CT-value.