ABSTRACT
Structural contribution of a shoulder to the performance of concrete pavements is well recognized. However, it is traditionally quantified through reduction of critical stresses in concrete slabs when the load is applied at the traffic lane/shoulder edge. Oversized vehicles, such as farm equipment, tend to wander across the joint and onto the shoulder of the road. Conventional mechanistic models predict that placement of a portion of a wheel load on an aggregate shoulder causes stresses in the concrete slab to significantly reduce. As a result, such loading scenario is not considered in the design procedures. In this study, the effect of wheel wander on stresses in the concrete slab is reconsidered. Two structural models are developed using the finite element program ISLAB2005. Both tied concrete and aggregate shoulders are considered. The performed analysis provides an insight into the effect of vehicle loads that span across the lane/shoulder joint. Recommended considerations for refinement of the current concrete pavement design practices for low volume concrete roads are provided.
