Experimental methods for the evaluation of aggregate resistance to polishing, abrasion, and breakage

This paper presents the development of new methods for measuring aggregate resistance to polishing, and degradation. These are important properties that influence pavement skid resistance and resistance to distresses under traffic loading. The aggregate imaging system is used to measure aggregate surface texture after different polishing time intervals in the micro-Deval test. Mathematical functions are then used to describe the initial texture, rate of polishing, and final texture. Aggregate abrasion is quantified by the percent difference in surface angularity before and after the micro-Deval test, while aggregate breakage is described by the weight loss in this test. The efficacy of the new methods is demonstrated through the analysis of aggregates from different sources that exhibit a wide range of properties. In addition, the new methods are verified by comparing the measured aggregate properties to the degradation of these aggregates in hot mix asphalt mixtures due to compaction forces.