New Test Method for Measuring Reflective Cracking in Hot-Mix Asphalt Overlay Pavements

Abstract

Reflective cracking is a common distress in hot-mix asphalt (HMA) overlay. A test method that can provide comprehensive information about reflective cracking is thus needed. In this study, an apparatus named Joint Motion Simulation System (JMSS) was developed, which consists of two hydraulic servo-systems and a temperature chamber. A newly developed reflective cracking test method (NRCTM) based on JMSS was proposed, which is applicable for airport pavement. This method considers the influences of both traffic and thermal loads under controlled temperature conditions. Laboratory tests were conducted to verify both repeatability and sensitivity of the NRCTM. The tests results revealed a coefficient of variation that was lower than 13%, indicating that the NRCTM exhibited satisfactory repeatability. In addition, the method was sensitive to four factors: test temperature, combination of loads, compaction of specimen, and type of mixture. Moreover, three types of interlayer structures were evaluated with the NRCTM: geotextile, stress-absorbing layers, and atactic polypropylene modified linoleum. The geotextile performed better than the other two interlayer systems. Thus, the NRCTM can be used for measuring the reflective cracking in HMA overlay with acceptable repeatability and sensitivity.