Analysis of Rigid Pavement Built with Multi-layer Concrete Slabs Resting on Pasternak Foundation

Abstract

Rigid pavement construction is emerging due to its long term performance and less maintenance cost. Its rigidity and high modulus of elasticity tend to distribute load over a wide area of foundation, resulting in very low deflections under traffic and environmental loading. Thus a major portion of the structure capacity is imparted by slab itself. Multi-layer slab is the composition of several superposed concrete layers of different quality. An idea is that lower quality material can be sandwiched in the neutral axis zone. This paper deals a structural analysis of the three layered structure resting on the Pasternak foundation subjected to traffic loading. The three layered structure is replaced by an equivalent single layered structure. An assumption was taken that the deflection at the surface of the upper layer may be considered to be equal with the deflection at the bottom of the lower layer. The mechanical characteristics of the equivalent structure depend on the mechanical characteristics of the different layers and the various adhesion conditions at the interfaces. Adhesion condition are full slip at each of the interface, full friction at the first interface as well second interface, full friction at both interfaces and partial friction at all interfaces. Analytical solutions are arrived and structural responses are investigated. It has been found that the structural responses for full friction case showed significant results. This study is made towards enhancing current design method and economic construction.