气候作用对沥青混合料性能的影响

Effect of long-term climate on performance of asphalt mixture

气候作用(如雨、日、冰)是沥青路面老化的主要原因之一,这些气候因子对沥青混合料影响可能是长期雨天或晴天的老化过程,也可能是由于温度变化范围大而引起的一系列冻融循环,然而,室内研究主要集中在气候作用的短期效应上。因此,本文针对两种不同的沥青混合料(密级配和开级配),分析长期受潮、多次冻融循环和不同热老化时间下其强度和刚度的变化规律。研究发现:在水分作用下空隙率对沥青混合料的长期性能演变有显著影响,这是一个不同于其他两种气候因子的可逆过程。另一方面,冻融循环对密级配沥青混合料的影响更大,无论空隙率如何,冻融循环都是一个短期过程,而热老化对两种沥青混合料的性能变化最小。

climate effect(such as rain,day and ice)is one of the main reasons for asphalt pavement aging.The effect of these climate factors may be the long-term process of asphalt mixture aging in long-term rain or sunny days,or a series of freeze-thaw cycles caused by wide range of temperature changes.However,the indoor research focuses on the short-term effects of climate action.Therefore,this paper aims to analyze the changes of strength and bearing capacity of asphalt mixture under long-term moisture,multiple freeze-thaw cycles and different heat aging days.In this paper,for two different asphalt mixtures(dense type and open type),it is found that the void ratio has a significant effect on the long-term performance evolution trend of the mixture under the action of moisture,which is a reversible process different from the other two climatic factors.On the other hand,the freeze-thaw cycle has a greater impact on the dense mixture.Regardless of the void ratio,the freeze-thaw cycle is a short-term process,and the thermal aging has the smallest change on the performance of the two asphalt mixtures.