服役温度范围内沥青混合料长期老化室内模拟与性能评价

Laboratory Simulation and Performance Evaluation of Long-Term Aging of Asphalt Mixtures at Service Temperatures

为解决现有室内老化模拟方法与实际沥青路面老化梯度和服役温度存在差异的问题,设计了一种基于纯氧加速老化的新型室内长期老化方法,以模拟服役温度范围内沥青混合料的老化行为。通过傅里叶变换红外光谱和动态剪切流变仪研究了沥青混合料老化性能随时间和空间的演变规律。研究结果表明,新方法能有效模拟服役温度范围内压实沥青混合料的老化行为,老化程度接近标准长期老化试验水平。随老化时间和温度的增加,沥青混合料AC‒13和SMA‒13老化程度加重,其中SMA‒13的老化程度仅为AC‒13的1/5。同时,两种混合料的高温性能随之改善,而疲劳寿命下降。随着老化深度的增加,两种混合料的老化指数和高温性能逐渐降低,而疲劳寿命显著增加。在不同老化条件下,SMA‒13表现出更优异的抗老化和抗疲劳性能,尤其在低应变水平下。方差分析表明,老化时间对亚砜基和高温性能的影响显著,但对羰基和疲劳寿命无显著影响;老化温度对老化指数、高温性能和疲劳寿命均无显著影响,而老化深度仅对0.1 kPa下不可恢复蠕变柔量有显著影响,对其余指标无显著影响。

To address the discrepancies between existing laboratory aging simulation methods and the actual aging gradient and service temperature of asphalt pavements,this paper proposed a novel indoor long-term aging method based on the pure oxygen accelerated aging,aiming to simulate the aging behavior of asphalt mixtures at service temperatures.The investigation of the aging properties of asphalt mixtures with time and space was conducted using Fourier transform infrared spectroscopy(FTIR)and dynamic shear rheometer(DSR).The results show that the novel aging method proposed can effectively simulate the aging behavior of compacted asphalt mixtures within the service temperature range,achieving an aging degree close to that of standard longterm aging tests.With the increase of aging time and temperature,the aging degree of AC-13 and SMA-13 mixtures both increases,and the aging degree of SMA-13 mixtures is only 1/5 of that of AC-13 mixtures.Concurrently,the high temperature performance of the two mixtures increases,while the fatigue life decreases.With the increase of aging depth,the aging index and hightemperature performance of AC-13 and SMA-13 mixtures gradually decrease,whereas the fatigue life significantly increases.Under different aging conditions,SMA-13 mixtures show a superior aging resistance and fatigue resistance than AC-13 mixtures,particularly at low strain levels.ANOVA indicates that the aging time significantly impacts the sulfoxide index and high-temperature performance,but has no significant effect on the carbonyl index,high-temperature performance,and fatigue life.The aging depth only significantly impacts nonrecoverable creep compliance at 0.1 kPa,with no significant effects on the other evaluation indexes.