Influence of particle size selection methods on asphalt mixtures produced with lateritic aggregates

Abstract The aggregates of asphalt mixtures provide resistance to most of the load applied to the pavement, so it is important to evaluate the physical and mechanical properties of the aggregates. In some regions of Brazil, the availability of traditional aggregates (granitic) is becoming scarce due to the rapid increase in infrastructure projects and the longer distance of deposit to the paving works. To address the above issues, we tried to find substitutes for granitic aggregates in asphalt mixtures. Laterite is a tropical or sub-tropical weathering product, abundant material in the North and Northeast of Brazil. The study aimed to evaluate the performance of asphalt mixtures produced with lateritic and granitic aggregates and verify the influence of National Department of Transport Infrastructure (DNIT), Bailey, and French particle size selection methods in the mixtures, through mechanical tests. The Dominant Aggregates Range (DAR) technique was used to evaluate the behavior of the mixtures in terms of permanent deformation. The asphalt mixtures were analyzed through dynamic modulus, flow number, fatigue test, resilience modulus, and Modified Lottman test. The analysis of the mixtures by the DAR method showed results that did not corroborate the results of the mechanical tests. However, all the analyzed mixtures showed good performance regarding permanent deformation, especially the mixtures with lateritic aggregates. The asphalt mixtures produced with lateritic aggregates present better mechanical performance, enabling their use mainly in countries with a tropical climate and low rainfall, such as the northeast region of Brazil. The French method showed equivalent mechanical performance and even superior to the DNIT method, commonly used in Brazil.