Advancements in Microsurfacing Mix Design: Evaluating the Impact of Stabilizers and Additives on Performance Improvement

The rapid expansion of asphalt pavements worldwide has led to increased concerns regarding their deterioration, which incurs significant financial costs and environmental pollution. To mitigate such issues, the application of preventive maintenance treatments like microsurfacing before irreparable damage occurs is crucial. However, designing effective microsurfacing systems presents challenges, particularly in achieving stable asphalt emulsions. The use of suitable stabilizers can address these challenges. This study aims to fill the existing research gap by evaluating the performance of waste engine oil (WEO), waste cooking oil (WCO), and gas oil as stabilizers at three different concentrations. Additionally, to ensure the compatibility of these materials with other additives and to achieve a comprehensive assessment, three different penetration-grade bitumens, including one polymer-modified with polyphosphoric acid (PPA), were utilized. Furthermore, two distinct emulsifiers and two types of fibers—glass and polypropylene—were incorporated into the study. The performance of the microsurfacing mixtures was evaluated through a series of tests, including the cohesion test, wet-track abrasion test (WTAT), loaded wheel test (LWT), mixing time determination test, and consistency test. The results were subsequently analyzed using statistical methods. The findings revealed that gas oil exhibited the best performance as a stabilizer, followed by WCO and WEO. Moreover, the results indicated that the stabilizer type and concentration, as well as the emulsifier type, are critical parameters influencing the performance of microsurfacing systems.