Analysis of the effect of unbound granular base characteristics on the performance of flexible pavements

Abstract

The influence of aggregate properties on the mechanical behaviour of granular materials is widely recognized in the literature, but default values are considered most of the time for pavement design. This limits their consideration to accepting materials that show values in defined ranges of indicative properties. It is expected that materials with similar particle size distributions but different characteristics will perform differently. This work evaluated the influence of considering the characteristics of the aggregate base and its effect on stiffness and damage. Two approaches were used to modify the adjustment coefficients in stress-dependent resilient modulus models to consider the characteristics of the granular materials. The results showed that thin pavements were particularly sensitive to these characteristics, with pavement capacity expected to be higher than in default models when considering crushed aggregates. In contrast, the capacity may be as low as 40% of the conventional estimate for partially crushed aggregates.