Research On Water Damage Performance Of Asphalt Pavement Under Freezing Rain And Ice-snow The Extreme Climate

In 2008, 20 provinces of southern China had suffered the extreme climate disaster such as snow, ice, freezing rain and so on. The road engineering had been influenced by the extreme climate, which degraded the pavement performance and service functions, caused the destruction of the road infrastructures. In China, more than ninety-five percent of the trunk road and highway are the asphalt pavement structure type. The cycle-function results in the frost heaving of asphalt pavement and the accelerated aging of asphalt by snow, ice, deicing chemical, ect. Through water seepage is freezing and thawing repeatedly, the asphalt pavement will appear the water damage phenomenon such as loose ground and road pit. Owing to the influence of this water damage is multi-level and multi-angle, which requires to introduce new approaches to analyze the water destruction effects of ice-salt for asphalt mixture.This thesis will obtain from the material and gradation structure, the studied emphasis is to choose the admixture 1% of the slaked lime of the AC-13, the CAM of R&D of Texas of the USA and the AC-13C, which is the common structure in China. This thesis includes the following three aspects:First, the deicing chemical is mainly chlorine salt, which has the destructive effect to the asphalt pavement and the environment. In order to analyze the destructive effect of water damage of asphalt pavement by cryosel in the extreme climate condition, the chloride ion diffusion model is established in view of the second Fick’s diffusion law of the transport phenomena discipline.Secondly, according to the characteristic of asphalt pavement to resist low temperature and strong rainfall, Optimized design the gradation of asphalt mixture, With a view to achieve the purpose to get mixture characteristic of compacting, small-rate air, and Anti- High Temperature permanent deformation, determined the best optimal asphalt content of different asphalt mixture by testing the volume index of marshal test piece. Simultaneously three types of asphalt mixture satisfy the requirements of "Technical Specifications for Construction of Highway Asphalt Pavements"Finally, according to climatic conditions of freezing rain and ice-snow, it is the performance testing of asphalt pavement, mainly include the water stability test, the low temperature anti-crack test, the wheel tracking test, the antiskid characteristic test and so on. The comparison results indicate that the AC-13 with slaked lime has good water stability and excellent performance of other aspects; Although CAM is slightly inferior in high temperature performance and antiskid characteristic, the CAM-13 has the good waterproof ability, the good anti-water damage ability and low temperature anti-cracking ability. This new type of asphalt mixture needs more entity project examination, which has broader applicative and disseminative value.