Soil-gravel in flexible pavement bases: Evaluation of performance in fatigue using the medina

Abstract

The application of alternative materials in replacement of bases and sub-bases composed by materials that are commonly used on road construction can be an excellent alternative, aiming at savings and satisfactory performance to the new highways. It is known that the current design method deprives itself of important aspects related to parameters of the resistant capacity of the materials, therefore it became necessary to develop a new methodology of empirical-mechanistic design, called MeDiNa. One of the factors considered by this new methodology is the resilient behavior of the materials. Thus, in this work, soil samples compacted in intermediate energy by Proctor test method were analyzed and three mixtures of lateritic clay soil and batch gravel were proposed, in percentages of 25, 30 and 35% of soil, to be used in road structural layers, in order to understand which one would represent the best behavior when applied to the low, medium and high volume of traffic, in addition to an economic viability analyze. The results demonstrate good resilient behavior of the samples, with emphasis on mixture 2 (intermediate mixture), which had correlation coefficients in order of 0.9. The application of this mixture was simulated as the base layer of an existing pavement structure (reference pavement) and its fatigue behavior was analyzed, resulting in a superior performance, with lower percentage of cracked area over its useful life, and a cost reduction up to 60%.