Characterisation of air voids in w-fam samples using x-ray ct imaging

Abstract

This study documents the use of high-resolution X-Ray Computed Tomography to characterise air void distribution in Fine Aggregate Mixtures (FAM) prepared using Warm Mix Asphalt (WMA) additives (W-FAM). Specimens were imaged before and after subjecting them to repeated creep and recovery test. The produced images were digitally analysed to measure the air voids size in the samples and changes that occurred due to testing. While the same compaction effort was used to prepare all specimens, mixes prepared using WMA additives had less percentage of air voids than the control mix. In general, the increase in percentage of air voids happened in specimens that had larger air voids prior to loading. In addition, there was more changes in air voids in the original (control) specimens than the W-FAM specimens.