Innovative Treatment of Crack Defects and Skid Resistant Deficiencies in Old Asphalt Pavement Using a Prefabricated Flexible Ultrathin Overlay

Abstract

This study aims to develop a prefabricated flexible ultrathin overlay that can quickly and effectively repair cracks, particularly reticulation cracks, in old asphalt pavements while improving skid resistance. The overlay consists of a combination of an aggregate, a binder, and a geotextile; its unique structure results in a thickness of only about one-third of that of traditional ultrathin overlays. Its tensile strength, skid resistance, flexibility, waterproofing, interlayer bonding, and long-term service performance were evaluated through a series of tests. The results indicated that basalt, styrene butadiene styrene–modified emulsified asphalt, and warp-knitted polyester fiberglass fabric was the best combination. The proposed steady-state equation could reduce the test duration by more than 20%. The best interlayer binder was rubber asphalt with an optimum dosage of 0.9 kg/m2. The effect of temperature on interlayer bonding properties was more significant than that of the loading rate. The overlay maintained good waterproofing, skid and crack resistance, and interlayer bonding properties after a medium-scale accelerated loading test.