THE RELATIONSHIP BETWEEN DYNAMIC WHEEL LOADS AND ROAD WEAR

This report describes a series of three accelerated pavement tests undertaken, between 1993 and 1998, at the Canterbury Accelerated Pavement Testing Indoor Facility (CAPTIF) in Christchurch, New Zealand, to determine the relationship between dynamic wheel loads and pavement wear, particularly for the thin-surfaced unbound granular pavement structures widely used in New Zealand. Conclusions are that the wheel path subjected to higher dynamic loading showed a significantly greater variation in wear than the wheel path with lower dynamic loads. Reducing the structural variability in the pavement structure and reducing dynamic loading will result in a more uniform distribution of wear and will lower the maintenance requirements. Both pavements withstood considerably more load applications than predicted by most design models, though the Austroads pavement design guide provides the most accurate predictions of pavement life. If the design models accurately reflect the performance of in-service pavements, construction variability, aging and environmental influences are suggested as significant contributors to pavement wear. (a)