The Federal Aviation Administration (FAA) currently lacks a model of reflection cracking for the thickness design of hot-mix asphalt (HMA) overlays on existing concrete pavements. The standard FAA thickness design program FAARFIELD does not consider this important distress mode. To develop such a design model, the FAA performed full-scale tests under controlled loading conditions, using an indoor test rig at the National Airport Pavement Test Facility (NAPTF) that mimics the overlay response to temperature cycles. Recently, the FAA also constructed a set of outdoor overlay test pavements subject to simulated aircraft loads and natural weather cycles. In parallel with these full-scale tests, the FAA performed laboratory analyses to characterize the fracture properties of the tested HMA under repeated loads. This paper presents laboratory test results on the samples extracted from Full-Scale test HMA overlays. Specific tests included the Disk-Shaped Compact Tension test in monotonic mode, the Texas Overlay test, as well as nonstandard tests of notched and un-notched samples in the Texas Overlay Tester. DCT tests indicated decrease in fracture energy with temperature drop below freezing. Overlay test results on notched specimens revealed high sensitivities of fatigue strength, fracture energy, and crack propagation rate to ligament length. On un-notched specimens, fracture energy and strain energy were able to capture the effect of displacement variations on the crack growth. Analyses determined the value of critical energy release rate (Jc) of the studied HMA mixture to be in well agreement with the literature-reported fracture resistance limit of asphalt materials.                                                                

DOI: https://doi.org/10.1061/9780784483527.013

Laboratory Evaluation of Fracture Properties of Airfield Pavement Asphalt Mixtures for Reflection Crack Modeling

Welcome to the International Airfield and Highway Pavements Conference of the Transportation & Development Institute (T&DI) of ASCE. This international conference will provide an unrivaled chance to interact and exchange information with worldwide leaders in the fields of highway and airport pavements, as well as airport safety technologies.

This conference will bring together designers, project/construction managers, academics, and contractors from around the world to discuss the state-of-the-art implementation, construction, design, in airfield and highway pavements.