Analysis of physical and mineralogical properties of aggregate on strength and durability of asphalt concrete

Abstract

Asphalt is made by mixing aggregates, filler and binder materials together according to pre-determined ratios. Out of the total asphalt weight, 94% to 95% consists of aggregate. It is not surprising that the performance of asphalt concrete mixtures is influenced by the properties of their aggregate blends, such as gradation, shape (angularity and elongation), texture (roughness) and mineralogy. In asphalt concrete, numerous studies have related gradation, shape, and texture of the aggregate to durability , workability , shear resistance, tensile strength, stiffness, fatigue response, rutting susceptibility, and optimum binder content of the mixtures. However, a few has described about the influence of mineralogy on characteristics of asphalt. This research has been carried on to make an effort to fill that gap between the aggregate mineralogical properties and the characteristics of asphalt concrete. Under the research, a number of representative aggregate samples were collected from different quarry sites which are currently used in the process of manufacturing asphalt all over the country. The samples were subjected to a series of tests in order to determine both physical and mineralogical properties. Marshall stability and flow values of the asphalt mixtures were determined to assess the properties of asphalt made using the collected aggregates. Finally, using test results, an analysis was conducted followed by the conclusions made using the test results, a set of recommendations were proposed.