Effect of Thin Asphalt Surfacing in Reducing Thickness of Concrete Pavement by using Finite Element Method

One of the limitations to implementing roller compacted concrete (RCC) pavement in Iran is lack of proper surface texture for high-speed traffic. One method to overcome this issue is to apply a thin asphalt surfacing on RRC pavement. This wearing course is unable to contribute significantly to the increase in stiffness of the structural system; however, if the composite slab system is treated as a beam in bending, the effect of asphalt surfacing could be calculated directly by assessing its effect on the neutral axis. The shift in the neutral axis is translated to a reduction in the concrete stress for a given bending moment as compared to the no-surfacing condition that, consequently, could reduce the concrete slab thickness. In this paper, the finite element method has been used to evaluate the reduction in the thickness of the concrete. In doing so, thin asphalt wearing course with conventional thickness (4 and 5 cm) on RCC pavement of 20 to 25 cm thickness was modeled by using the computer code "ABAQUS". Analysis of vertical stress and tensile strain of concrete substrate showed that reduction in the concrete thickness depends on thicknesses of the concrete pavement and thin bituminous wearing course. Average thickness reduction was calculated as approximately 10% to 15% of the concrete thickness.