Second Distress Mechanism of Repaired Potholes and Performance Evaluation of Repair Techniques from Multiple Perspectives

Abstract

Potholes are typical scattered distresses on asphalt pavements, severely impairing traffic safety and pedestrian safety due to delayed repair time and secondary distress. Aiming to extend the service life of repaired potholes, this study develops a pothole repair technique characterized by repair materials with superior performance and adhesive materials with high bonding strength. Firstly, the mechanical analysis for repaired potholes was conducted via finite element simulation, and thereafter, corresponding technical measures were derived to prevent the recurrence of distress in repaired potholes. Secondly, according to the material composition of solvent-based cold-mix asphalt (SCMA) and emulsified-based cold-mix asphalt (ECMA), pavement performance testing methods were proposed to test and evaluate their forming strength, high-temperature stability, low-temperature crack resistance, and water stability. On this basis, interlayer shear tests, pull-out tests, and field pothole repair cases with varying repair materials and adhesive materials were conducted, and the interfacial bonding strengths with the old pavement were then compared to optimize the pothole re-pair technique. The results showed that (1) increasing the repair material modulus and interfacial friction coefficient reduces the pressure strain (σy) and pressure stress (εy), thereby decreasing the risk of secondary dis-tress; (2) ECMA exhibits superior pavement performance, with strength and rutting resistance 49.7%–64.6% higher than SCMA; (3) the combination of ECMA and WER-EA achieves the highest interfacial pull-out and shear strengths, with their values 76.7%–78.2% higher than SCMA+WER-EA); and (4) after 1 year of opening to traffic, potholes repaired with ECMA+WER-EA show minimal thickness loss of 0.2 cm and no aggregate peeling at the edges, thus being recommended as the optimal solution for repairing potholes. This study clarifies the secondary distress mechanism of repaired potholes and provides an optimal repair scheme (ECMA+WER-EA) for engineering applications.