Correlations and preliminary validation of laboratory asphalt binder and HMA reflective cracking resistance to field performance of in-service highway sections

Abstract

Reflective cracking is one of the dominant distress modes occurring when hot-mix asphalt (HMA) overlays are placed over existing cracked flexible and/or jointed rigid pavements. Various tests have been conducted in the literature for measuring, characterizing, and quantifying the cracking resistance potential of HMA mixes in the laboratory. Asphalt-binder is one of the key constituent elements that significantly influences and controls the fracture behavior and cracking performance of hot-mix asphalt (HMA), both in the laboratory and field. In particular, the low-temperature rheological properties of the asphalt-binders are very critical in terms of improving the HMA fracture properties in the laboratory and ultimately mitigating cracking in the field. The Elastic Recovery (ER) and Bending Beam Rheometer (BBR) are the most widely used laboratory test methods for evaluating and quantifying the asphalt-binder behavior at low temperatures, mostly using the ductility (ER), stiffness (S), and m-value parameters. Some cracking test related to mixes have been studied, both of dynamic and monotonic loading modes. However, one key challenge with most of these laboratory tests is correlations and validation with field performance data. Quite often, field data availability is a challenge or otherwise, needs costly long-term performance monitoring. Using the Texas flexible pavements and overlays database, namely the Texas Data Storage System (DSS), as the data source, this study was conducted to correlate and preliminarily validate the asphalt-binder low-temperature properties (measured using the BBR and ER tests) and laboratory monotonic-loading overlay tester (OT) to the field crack (reflective) performance of in-service highway sections.