考虑水-温循环的SBS改性沥青复数剪切模量预估模型

为探寻季节性冻土区多次水-温循环后沥青胶结料特征官能团变化与复数剪切模量之间的关系，联合FTIR和动态剪切流变（DSR）试验，对经0、3、6、9、12、15和18次水-温循环后的苯乙烯-丁二烯-苯乙烯嵌段共聚物（SBS）改性沥青进行测试，探明了多次水-温循环下SBS改性沥青复数剪切模量和特征官能团的变化规律；采用灰色关联熵分析理论数学模型，明确了复数剪切模量与特征官能团含量变化的关联程度；基于麦夸特法和通用全局优化算法对不同温度和频率下DSR测试的SBS改性沥青复数剪切模量G*及FTIR测试官能团变化指数进行多元统计回归分析，提出了SBS改性沥青复数剪切模量的预估模型。结果表明:多次水-温循环使沥青发生了水-温老化，但SBS改性剂对沥青水-温老化具有抑制作用；随着水-温循环次数的增加，沥青FTIR图谱中亚砜基与羰基呈现出明显的增大趋势；SBS改性沥青特征官能团变化对复数剪切模量影响程度由大到小的排序为脂肪族化物 > 非对称脂肪族化物 > 芳香族化合物 > SBS含量（苯乙烯+丁二烯） > 亚砜基 > 羰基；多次水-温循环后SBS改性沥青复数剪切模量随着特征官能团含量变化呈现出多元线性关系。 

Prediction model of complex shear modulus of SBS modified asphalt binder considering water-temperature cycles

In order to explore the relationship between the change of characteristic functional groups and the complex shear modulus of asphalt binder after repeated water-temperature cycles in seasonal frozen area, the SBS modified asphalts binders after 0, 3, 6, 9, 12, 15 and 18 times water-temperature cycles were tested by combing FTIR with dynamic shear rheological (DSR) testing techniques. The disciplinarian of complex shear modulus and the characteristic function groups of styrene-butadiene-styrene (SBS) modified asphalt binder under multiple water-temperature cycles were ascertained. Correlation between the complex shear modulus and the content of the characteristic functional groups was clarified based on the mathematical model of gray relational entropy analysis. Multivariate statistical regression analysis of the complex shear modulus G^* of the SBS modified asphalt binder and the change functional group index by FTIR test under different temperatures and frequencies were conducted based on the Levenberg-Marquardt method and the generalized global optimization algorithm, and the prediction model of complex shear modulus of SBS modified asphalt binder was proposed. The results show that the asphalt binder has been aged after multiple water-temperature cycles, but SBS modifier has inhibitory effect on asphalt aging. The sulfoxide and carbonyl groups in the FTIR spectra of asphalt binder show an obviously increasing tendency with the increases of water-temperature cycles. The aliphatic is the highest of the six for SBS modified asphalt characteristic functional groups changes on the complex shear modulus impact, with the asymmetric aliphatic, aromatic compounds, styrene plus butadiene, sulfoxide and carbonyl following. The complex shear modulus of the SBS modified asphalt binder after multiple water-temperature cycles shows a multiple linear relationship with the change of characteristic functional groups.