玄武岩纤维沥青混合料开裂性能预测

Prediction of Crack Resistance of Basalt Fiber Reinforced SMA-13 Asphalt Mixture

为了对玄武岩纤维沥青混合料开裂性能进行预测研究,选用从不同老化程度的沥青玛蹄脂碎石混合料(SMA-13)中抽提的沥青样品的红外光谱参数,对混合料开裂性能参数进行预测分析。首先,选择美国州公路及运输协会(AASHTO)沥青混合料室内模拟老化手段,制备未老化、短期老化和长期老化SMA-13沥青混合料样品,并对其进行理想开裂测试(IDEAL-CT)。分析总结了沥青混合料裂缝形成及扩展阶段的关键参数,即开裂形成功(W_(initial))和开裂扩展指标(CT_(index))。然后,采用抽提试验对不同老化阶段的混合料样品中的沥青材料进行提取,并对其进行红外光谱分析。最后,采用灰色关联分析方法,选取了与W_(initial)和CT_(index)关联度最大的几种红外光谱参数,建立预测模型。试验结果表明:随着老化程度的加深,沥青混合料开裂性能逐渐降低。在未老化、短期老化、长期老化阶段,与未掺玄武岩纤维的混合料指标相比,玄武岩纤维沥青混合料的W_(initial)指标分别高9.4%、13.0%和16.6%。相对应的CT_(index)指标分别高69.8%、95.2%和116.2%。沥青材料的红外光谱参数可以用来对混合料的开裂性能进行预测。

In order to predict the cracking resistance of the basalt fiber modified asphalt mixture,this paper selectd the Fourier transform infrared(FTIR)spectrum parameters of the asphalt sample extracted from the stone matrix asphalt mixtures(SMA-13)with different aging degrees,and then conducted the prediction analysis of the cracking performance parameters of the mixture.Firstly,unaged,short-term aged and long-term aged SMA-13 asphalt mixture samples were prepared according to the procedures of American association of state highway and transportation officials(AASHTO)asphalt mixture indoor simulation aging method,and the ideal cracking test(IDEAL-CT)were conducted.The key parameters in the crack formation and propagation process were analyzed and concluded,which is the crack formation work(W_(initial))and the crack propagation index(CT_(index)).The asphalt materials in the asphalt mixtures with different aging degrees were extracted by using the asphalt extraction experiment,and then the FTIR spectrum analysis was conducted.In the end,grey correlation analysis was utilized to select several infrared spectrum parameters with the greatest correlation with W_(initial)and CT_(index)to establish the prediction model.The test results show that with the increase of the aging degree,the crack cracking performance of the asphalt mixture are gradually decreased.In the unaged,short term aged and long term aged phase,the W_(initial)index of the basalt fiber modified asphalt mixture are increased by 9.4%,13.0%,16.6%compared with the asphalt mixture without basalt fiber.The corresponding value of the CT_(index)are increased by 69.8%,95.2%,116.2%respectively.The FTIR spectrum parameters of the asphalt material can be adopted to predict the crack resistance indexes of the mixture.