ABSTRACT
In cooperation with the United States Transportation Research Board and the Ontario Ministry of Transportation, researchers at Carleton University in Ottawa, Canada have developed the In-Situ Shear Stiffness Test (InSiSST™) – a new field test facility for measuring shear properties of compacted asphalt concrete layers. This paper has two primary objectives. Firstly, the InSiSST™ facility itself is introduced, including the test procedure used for assessing pavement layer shear properties. Secondly, results gathered with InSiSST™ while testing in Petawawa, Ontario during the summer of 2000 are also presented. The Petawawa site is of particular interest to North American road authorities as it is part of the SPS-9A (Superpave evaluation) experiment of the United States Long Term Pavement Performance project. Results obtained with this investigation indicated that mix shear stiffness values obtained from InSiSST™ testing are highly correlated with measured rutting at the test site and better characterize the pavement performance than laboratory test parameters such as resilient modulus. With continued refinement and testing, it is hoped that InSiSST™ will become a valuable test facility for the design and quality control of hot mix asphalt concrete pavements.
