Study On Performance Evaluation And Maintenance Mechanism Of Asphalt Pavement Silicone Maintenance Materials

Preventive maintenance of asphalt pavement is of increasing interest to highway agency and engineers, and many preventive maintenance materials based on emulsion asphalt are used all over the world, but other kinds of maintenance materials is limited. The objective of this paper is to investigate the effect of silicone maintenance materials on properties of asphalt and asphalt mixture and its maintenance mechanism.Firstly, contact angle test was conducted to evaluate the waterproof mechanism of silicone maintenance materials, and then the simple penetrate test, penetrability coefficient test and freezing-thawing test were used to evaluate the waterproof ability of silicone maintenance materials on asphalt mixture. The results show that contact angle between silicone maintenance materials and water is higher than 90°, which indicate silicone maintenance materials have excellent waterproof ability. In addition, the results also indicate the silicone maintenance materials can permeate into the void of asphalt mixture to prevent water form it.Furthermore, UV radiation aging test on asphalt and heat oxidative aging test on asphalt mixture were performed to evaluate the aging resistance of silicone maintenance materials. The results show that applying silicone maintenance materials decrease rutting parameter of UV radiation aged asphalt. What is more, the results also show that silicone maintenance materials can improve the low-temperature cracking resistance and fatigue resistance of aged asphalt mixture. Lastly, the effect of silicone maintenance materials on skidding resistance and polishing resistance of asphalt mixture were studied by means of British pendulum test, sand patch test as well as accelerated loading test. The results the silicone maintenance materials may decrease the skidding resistance of asphalt mixture to some degree, its still can meeting the requirements of China's specification. Moreover, the rubber powder and slag powder can be used to improve the skidding resistance of silicone maintenance materials seal on asphalt mixture. Accelerate loading tests show that silicone maintenance materials can still act as maintenance materials even when the surface of asphalt mixture is polishedThe result of this study mentioned above indicate that silicone maintenance materials exhibit excellent maintenance performance on asphalt mixture, which can support the applications of silicone maintenance materials in the future.