Factors affecting raveling resistance of cold-mixed ultra-thin chip seal

Abstract

Raveling, as one of the key distresses of the chip seal, affects the performance of the chip seal. A new cold-mixed ultra-thin (CMUT) chip seal consisting of modified emulsion, single particle size aggregate, and cement was designed. The wet track abrasion test (WTAT) was used to study the effects of curing conditions, submersion durations, amounts of aggregate, emulsion, and cement on both the early raveling and wet raveling resistance of the CMUT chip seal. In addition, the binder bond strength (BBS) test was also used to evaluate the moisture-induced damage with the prolonging of submersion durations. Additionally, the one-way analysis of variance was used to analyze the sensitivity of different factors. The results indicate that both temperature and curing time could significantly affect the raveling resistance of the CMUT chip seal. It is confirmed that submersion duration has significant influences on aggregate losses and pull-off strengths. With the prolonging of submersion duration, the moisture damage was severe but tending stable. Therefore, the raveling potential of specimens after being submerged for 6d was used to evaluate the wet raveling potential. According to the sensitivity analysis, it is confirmed that the emulsion dosage is the most significant factor affecting both the early and wet raveling resistance. Cement dosage is recognized to have dramatic effects on wet raveling resistance, while the effects are negligible when it comes to early raveling resistance. Furthermore, the amount of aggregate can hardly influence the raveling resistance of the CMUT chip seal.