考虑气候变化影响的沥青路面长期服役耐久性评估

Long-term durability performance assessment of asphalt pavement with the consideration of climate change impact

随着我国长寿命沥青路面技术的不断发展,由于沥青材料自身显著的黏弹特性,气候变化对沥青路面长期使用性能的影响逐步得到关注。文章围绕未来气温变化对沥青路面长期服役性能开展评估研究,首先通过2020年至2099年气候模型的气温预测数据分析我国不同地区的气温变化趋势,进而揭示不同碳排放强度情景(RCP4.5和RCP8.5)下路面设计温度参数变化规律,最后对我国典型地域不同结构类型沥青路面长期服役性能(永久变形与疲劳开裂)进行风险评估。经研究表明,气候变化背景下沥青路面温度设计参数的演化受未来碳排放情景与地域差异的双重影响,且温度调整系数的增长受地域影响较大但增长率的地域差异较小,基准等效温度的增长则受地域影响较小但不同地区的增长率差异相对明显;在不同碳排放强度情景下,考虑气候变化影响后沥青路面的疲劳寿命均不断减小、永久变形不断增加,且RCP8.5情景下气候变化的影响更为显著;不同城市之间气候变化对路面服役性能的影响存在一定程度差异,但总体趋势较为一致,青藏高寒高海拔地区对于气候变化具有更高的敏感性,需关注气候变化带来的永久变形损坏增长风险。因此,未来我国在继续研究优化低碳绿色路面新技术的同时,也需同步研究增强气候变化背景下沥青路面全寿命周期的高品质服役韧性。

With recent developments of the perpetual asphalt pavement technology, the climate change impact on the long-term pavement performance has been gradually concerned and addressed due to the viscoelastic(temperature-dependent) feature of asphalt materials.This paper foucuses on the assessment of the climate change effects on the asphalt pavement performance and durability.Firstly, the future air temperature trend from 2020 to 2099 across the country is analyzed based on the climate predictive models.Then, the evolution of the temperature coefficients in asphalt pavement design are investigated under various Representative Concentration Pathways(RCP) levels(RCP4.5 and RCP8.5).Finally, a risk assessment of the long-term pavement performance(permanent deformation and fatigue cracking) is performed for typical pavement structure types in various regions.The analysis results show that the temperature coefficients in asphalt pavement design under climate change is affected by both future carbon emission scenario and regional difference.The growth of the temperature adjustment coefficients vary greatly in different regions with relative low growth rate.The increase in reference equivalent temperature is less affected by the regions but exhibits obvious region-dependent growth rate.Under two different RCP scenarios, both the rutting and fatigue resistance are gradually reduced after taking into account of the climate change impact and the situation under RCP8.5 scenario is more challenging for pavement durability.Generally, the climate change impact on asphalt pavement performance among various regional cities display a consistent trend with slight discrepancy, in which the high altitude and severely cold area in Qinghai-Tibet plateau shows higher sensitivity to climate change especially for the permanent deformation potential.Therefore, with the developments of the low-carbon sustainable pavement technologies, it is also necessary to simultaneously enhance the life-cycle high performance resilience of asphalt pavements under climate change.