关键词: 道路工程, 道路混凝土, 抗冻性, 微观结构, 微观机理

Abstract: The frost resistance of road concrete is one of the most important factors in the durability of cement pavement.In order to understand the essence of road concrete frost resistance changes in the law，the freezing regularity of road concrete under different water-cement ratios and gas contents have been explored using the quick freeze method， and the stomatal structure and pore structure of road concrete have been analyzed using a Scanning Electron Microscope- Image Pro-plus (SEM-IPP) that were invented by the research group and Mercury Injection Porosimetry (MIP)，with the results of both macro and micro tests having been analyzed.The results show：the average pore diameter and stomatal spacing decreased by 30% and 22% respectively when the water-cement ratio decreased by 0.04，meanwhile，the frost resistance of road concrete increased by 15%; the average pore diameter and stomatal spacing decreased by 44% and 51% respectively, the frost resistance of road concrete increased by 35% when increased air entraining content 1/10 000.The increase in percentage of the <50 nm holes and the decrease of the average pore diameter and stomatal spacing resulting from the decreasing water-cement ratio or increasing air entraining content improved the internal structure of the pores and pore structures and reduced fractures，large holes，and hole connectivity，thus making the internal microstructure dense，which is beneficial to the improvement of frost resistance of road concrete.

Key words: highway engineering, road concrete, frost resistance performance, micro structure, micro-mechanism