Development of proposals for an Australian full scale accelerated loading pavement test facility

This paper describes the current proposals for the provision of a full scale accelerated loading pavement test facility for the Australian Road Research Board. The proposals developed from research into material characteristics, including laboratory testing and experimental road sections, studies of commercial vehicle types and loadings, the development and use of a reduced scale rolling wheel linear test track and a full scale repetitive loading simulator. A study of the economics of road vehicle limits, including the impacts of heavy vehicles and findings on the dynamic load performance of truck suspensions also support the need for the facility. Experiences with the performance of new major heavily trafficked pavements underly the need for an enhanced programme of pavement research defined to investigate layer and load equivalencies, especially with regard to the limits of performance of unbound materials; and the prediction of effects of axle loads greater than current legal maxima. The ideal research programme should test full scale pavements constructed by normal plant to provide for material and construction factors; use full scale loads on moving wheels at normal speeds and frequencies; allow for testing at accelerated rates and under higher loads to provide results within a reasonable time allowing for future potential increases in vehicle mass; be complemented by closely linked laboratory studies and field observations of trial sections in the road system. After consideration of methods involving analysis of the behaviour of existing pavements, controlled trafficking of trial sections and dynamic load simulation, it was agreed that there was a need for a full scale rolling wheel test track. The outline specifications for load, speed and configuration, and an initial test programme are given. The benefits of the research are increased knowledge of, and confidence in, design procedures, life, maintenance and reconstruction predictions, new materials and new pavement configurations (a).