Forensic laboratory tests to evaluate long-term performance of reclaimed asphalt pavements: Connecticut case study

This paper presents the most significant findings from the forensic evaluation of the long-term cracking performance of asphalt mix designs on the six Long-term Pavement Performance Special Pavement Study (LTPP SPS)-9A sections on Route 2 in Connecticut. The experiment targeted the comparison of permeability, stiffness, and low-temperature behaviour of Marshall and Superpave mixes with various performance grades of binders and reclaimed asphalt pavement content. The laboratory tests included measuring hydraulic conductivity by a Flexible Wall Permeameter, dynamic complex modulus by the Asphalt Mixture Performance Tester (AMPT), creep compliance and tensile strength by Indirect Tension Test, and fracture properties by Semi-Circular Beam (SCB) test. The evaluation of field performance included analysis of deflection basins and back-calculated elastic moduli from Falling Weight Deflectometer data as well as visual evaluation of surface distresses, such as cracking and weathering.