Performance test and evaluation index recommendation of fog seal on airport asphalt pavement

Fog seal technology has the advantages of convenient construction and rapid opening traffic, and it has a broad application prospect in the maintenance of airport asphalt pavement. However, the current evaluation indices of fog seal materials are not relevant enough to reflect their performance strengths and weaknesses comprehensively and systematically. Moreover, there is a lack of research on the non-emulsification class of fog seal materials. This research aims to compare and contrast various types of fog seal materials for airport asphalt pavement and provide suggestions for optimizing the fog seal materials and construction technology to achieve better results. This research tested the material, construction, and road performance of three fog seal materials: A, B, and C. Materials A and B are emulsified asphalt as matrix additive fog sealer, while material C is a special material fog sealer. The content of evaporation residue, surface curing performance, and rejuvenation performance test were optimized. The adhesion performance test was redesigned. Furthermore, the research performed a horizontal comparison of the material properties, construction performance, and road performance of the three kinds of fog seal materials. The key test methods and evaluation indices of fog seal were recommended by using statistical methods and discrimination analysis. The results showed that the emulsified asphalt as matrix additive fog sealer had a high content of evaporation residue and poor adhesion performance under low-temperature conditions, with a spalling ratio of over 75%. However, they had better adhesion performance with the aggregate under high-temperature conditions. The special material fog sealer had a low content of evaporation residue and excellent adhesion performance under low-temperature conditions, with a spalling ratio of nearly 0%. It also had the shortest surface curing time among the three materials. The special material fog seal has better comprehensive performance and better application prospects. According to the results of discrimination analysis, evaporation residue content, residue on sieve, and water dilution stability were recommended as evaluation indices of material performance. Adhesion of the material surface at the construction site and changes in material quality at 20 °C in the laboratory were recommended as evaluation indices of the surface curing performance. Adhesion (impact method) -10 °C and adhesion (boiling method) amount of sticky sand were recommended as evaluation indices of road performance. This research aims to provide guidance for the optimization of fog seal material and construction technology of airport asphalt pavement.