A B S T R A C T
A composite pavement is a pavement system in which a hot-mix asphalt concrete layer is placed over a rigid (concrete) base layer and it is widely used in road construction and rehabilitation applications. The concrete layer provides high structural load-bearing capacity, while the asphalt layer ensures the required functional performance. The interfacial bonding between the concrete and asphalt layers plays a critical role in the overall performance of composite pavements. Due to the significant difference in elastic moduli, deformation compatibility between the concrete and asphalt layers is limited; therefore, the interlayer bond is more susceptible to shear damage under the combined effects of traffic loading and environmental conditions. Inadequate interlayer bonding results in increased stresses and deflections within the composite pavement structure, leading to premature surface distresses. These distresses are particularly pronounced at intersections as a result of braking and acceleration forces. Consequently, ensuring a strong bond between the concrete and asphalt layers is essential for achieving satisfactory performance in composite asphalt pavements.
In this study, an inclined rigid laboratory test setup was developed to simulate both static and dynamic vehicle loads. The objective was to evaluate the stresses induced by braking loads as vehicles approach intersections and to investigate the mechanical behaviour of composite pavement layers. Furthermore, the performance of different interlayer types was compared with each other and with findings reported in previous studies in order to identify the most effective interlayer configuration. Composite test specimens were prepared using C25-grade cylindrical concrete samples with no interlayer and with a smooth interlayer, as well as specimens incorporating an MC-30 emulsion with a roughened interface and an epoxy interlayer. The results indicated that the highest bond strength and overall performance were achieved on surfaces treated with emulsion-coated rough aggregates and epoxy-applied interfaces.