Rigid Pavement

A rigid pavement is a pavement whose wearing course is a Portland-cement-concrete slab (with or without dowel/tie bars) that carries traffic loads primarily through its own flexural (beam) rigidity, distributing the load over a wide area of the supporting layer so the pressure on the subgrade is low. Unlike flexible pavements, the concrete slab — not the subgrade — provides most of the structural capacity, so the dominant design parameter is the concrete's flexural strength, with the subgrade/sub-base represented by the effective modulus of subgrade reaction (k).

In India rigid pavements (jointed plain concrete pavement, and increasingly continuously reinforced/whitetopping) are designed per IRC 58 using Westergaard-type slab stress analysis and cumulative fatigue damage from axle-load spectra, considering the critical combination of wheel-load stress and warping/temperature-differential (curling) stress at the edge/corner. Joint design (contraction, expansion, construction and longitudinal joints, with dowels and tie bars) controls cracking from shrinkage and thermal movement and is as important as slab thickness; rigid pavements cost more initially but offer long life and low maintenance with good durability under heavy/channelised traffic.