Assessment of Crushing Potential of Coarse Aggregates for Asphalt Concrete Mixtures

Abstract

This paper aims to evaluate the effectiveness of a mechanical test that can assess the quality of mineral aggregates commonly used to produce asphalt concrete, in relation to crushing potential, in a more consistent and repeatable manner. Several aggregate types including limestone, dolomite, sandstone, granite, and gravel were sampled from different locations around Texas. The aggregate samples were subjected to various mechanical aggregate tests, primarily the aggregate crushing value (ACV) (BS 812-110:1990) test. A new index, the aggregate crushing potential (ACP), is proposed for the ACV test to improve its characterization potential. The main output parameters from aggregate tests such as the Los Angeles abrasion, magnesium sulfate soundness, acid-insoluble residue, and micro-deval abrasion, which are routinely performed to discriminate the properties of coarse aggregates, were collected. In addition, the dynamic friction test was conducted to measure the friction properties of several of the aggregate sources. Analyses were carried out between the ACV test results and the measured aggregate parameters. The proposed ACP index was identified as a suitable indicator of the durability of coarse aggregates. From this study, the ACV test partnered with the ACP index showed potential to delineate the quality of aggregates, in relation to crushing resistance, more practically and consistently, and eventually may supplant more tedious aggregate test methods.