Field and Laboratory Evaluation of a Reflective Crack Interlayer in New Jersey

Abstract

A research effort consisting of both field and laboratory testing was undertaken to evaluate reflective crack relief interlayer (RCRI) mixes as a means of mitigating reflective cracking in composite pavements. Extensive field testing that included falling weight deflectometer (FWD) and weigh-in-motion (WIM) sensors was used to establish applied loads and the resultant movements in the pavement structure. The resultant field movements were used to establish testing parameters for the laboratory study. The purpose of the laboratory program was to evaluate the reflective cracking potential through bending and expansion-contraction-type movements of plant-produced asphalt mixes consisting of different aggregate gradations and asphalt binder types commonly used in New Jersey for portland cement concrete pavement overlays. Results indicate that the combination of FWD and WIM data can provide valuable information for establishing realistic parameters for laboratory validation of asphalt mixes. The laboratory study clearly illustrated the benefit of using RCRI mixes that consist of a fine aggregate gradation and polymer-modified asphalt binders to minimize reflective cracking potential. However, future efforts should include more fatigue-resistant mixes that would overlay the RCRI mixtures, as well as efforts to ensure better construction practices during their placement.