Evaluation of the effective parameters on shear resistance of interface in a geocomposite-reinforced pavement

Abstract

Application of geosynthetics is known as an important way to reduce and delay emergence of reflective cracks. However, reliance on these materials can have some disadvantages, including reduction of shear resistance in the interface between two HMA layers, along with emergence of some defects in areas on which vehicles brake, accelerate or turn. A large number of parameters affect the interlayer shear resistance. In this research activity, a double-shear device has been developed and evaluated in order to measure shear resistance between layers in the interface zone. The device is equipped by a system for application and control of normal compressive and tensile loading. In this research, using the L16 (2 × 2–4 × 4) orthogonal array, the factors that are most influential on the shear resistance of the interlayer zone reinforced by geocomposite are evaluated. Temperature, with effectiveness 2.4 times greater than that of the other parameters, the effect of which is relatively uniform, is found to be the most relevant parameter, followed by the tack-coat application rate. The findings indicate that the shear loading rate and geocomposite grid size have the next most significant contribution to the maximum shear resistance, both with and without application of normal load.