Advancing pavement preservation: Comprehensive analysis and optimization of microsurfacing mixtures with stabilizers, bitumen types, emulsifiers, and fiber impacts

Microsurfacing has emerged as a favored preventative maintenance solution in pavement engineering due to its economic efficiency, high effectiveness, and environmental benefits. This research, despite the complexity arising from the diversity of additives, conducts a comprehensive evaluation of the effects of various additives on microsurfacing performance. This includes stabilizers—whose significant impact has previously been overlooked—different types of bitumen, and fibers. Utilizing two types of bitumen with varying penetration grades, bitumen modified with polyphosphoric acid (PPA), two distinct emulsifiers, Type I (French) and Type II (Iranian), and four stabilizers (gasoil, petrol, petroleum, and engine oil) in three different percentages. Along with two types of fibers, the study examines their impacts on microsurfacing. The performance of the microsurfacing mixture was then assessed using Cohesion test, Wet-Track Abrasion Test (WTAT), Loaded Wheel Test (LWT), Mixing Time Determination Test, and Schulze–Breuer & Rock (SBRT) test. The findings indicate considerable improvements in microsurfacing performance with the recommended formulations. This study underscores the importance of proper additive selection, identifying gasoil stabilizers and Type I emulsifier as superior choices, though no significant difference was observed between emulsifiers Type I and II. The study suggests using Type II emulsifier for economic efficiency. Microscopic evaluations further confirm the critical role of 2 % gasoil in emulsion stability. Statistical results highlight the stabilizer amount as the most crucial parameter affecting microsurfacing performance. These insights emphasize the criticality of precise additive selection in optimizing microsurfacing efficiency and provide effective guidelines for the optimal design of microsurfacing mixtures.