Evaluation of Crack Development Through a Bituminous Interface Reinforced With Geosynthetic Materials by Using a Novel Approach

Abstract

Using interlayers made of geosynthetic materials has proved its effectiveness with respect to postponing the appearance of reflective cracking on the surface. In this regard, in a reinforced bituminous interface, the crack first propagates from its origin upward until it reaches the interlayer. When the interlayer has higher stiffness than its surrounding bituminous material, the crack path diverts horizontally along the interlayer plane until the whole energy of the crack dissipates. Nevertheless, this mechanical improvement needs to be further studied to quantify the reinforcement effects of geosynthetic materials in mechanistic-based design of reinforced sections. This study aimed to develop a laboratory test method that not only is able to illuminate the crack resistance effect of geosynthetics but is also able to differentiate the load–displacement curves among different types of reinforced bituminous interfaces. The results led to the advent of a new test device called the crack widening device in which reproducibility and statistical variability of the outcomes were all within the acceptable range. On this ground, using paving fabric showed superior performance among others with respect to energy dissipation capability and retarding the loss in the stiffness modulus during the crack propagation stage compared with the corresponding unreinforced cases. On the other hand, using the reinforcement grids led to a higher initial stiffness of the reinforced structure, especially when embedded between coarse hot mixtures.