Examining the durability of construction aggregate: Geological versus mechanical properties

Abstract

Physical testing of bedrock materials used for road building and related construction applications is standard engineering practice. Micro Deval and Los Angeles Abrasion are two of the most common tests used to determine the durability of coarse aggregate materials. These tests are time consuming and expensive. The mineralogical and textural properties of a rock are the main geological factors that influence its mechanical durability and its structural integrity and therefore its reliability as construction material. Despite this rather obvious connection, the link between geological properties and standard aggregate engineering tests for road surfacing materials has not been examined in detail. This study examines the relationship between the measured mechanical properties of a proposed aggregate material, its textural characteristics and its mineralogical composition. The two standard engineering tests, Micro Deval and Los Angeles Abrasion show only a very weak correlation despite the similarities in the equipment design. No correlation was found between any of the geological properties and the mechanical properties. The results of this study indicate that neither standard test can be considered reliable and that much more study is required in order to define a reasonable test of rock