低损耗因子复合改性沥青疲劳和自愈特性

Fatigue and Self-healing Performances of Composite Modified Asphalts with Low Loss Factor

摘要:

为探究损耗因子（tan δ）对SBS改性沥青疲劳寿命的调控作用，借助塑料润滑剂乙撑硬脂酸酰胺，制备了4种改性沥青，采用红外光谱仪、原子力显微镜和差示扫描量热仪测试了其微观特性，通过动态剪切流变仪分析了其损耗因子及连续、间歇疲劳参数的变化.结果表明：经羟基化处理的乙撑硬脂酸酰胺（HPT）含胺基和羟基，使沥青中轻组分极易填充至SBS相，其复合改性沥青低温柔韧性无劣化，70 ℃ tan δ显著降低，疲劳寿命大幅增加，自愈特性增强；未经端基处理的乙撑硬脂酸酰胺（HPT-E）仅含胺基，可增强沥青间分子相互作用，其复合改性沥青70 ℃ tan δ略小于2，疲劳和自愈特性均得到改善；经脱胺处理的乙撑硬脂酸酰胺（HPT-R）仅含羰基，对聚合物相网络密度略有提升，其复合改性沥青低温柔韧性增强，70 ℃ tan δ小幅降低，疲劳特性与SBS改性沥青相近，自愈特性增强.

Abstract:

To investigate the regulation of loss factor（tan δ） on fatigue life of SBS modified asphalts， four types of modified asphalts were prepared with the ethylene stearic acid amide as a plastic lubricant. The microscopic characteristics of modified asphalts were analyzed by the infrared spectrometer， atomic force microscope， and differential scanning calorimeter. The parameters during continuous and intermittent fatigue processes and the loss factor（tan δ） were measured by the dynamic shear rheometer. The results show that due to the hydroxyl and amino group， the hydroxylated ethylene stearic acid amide（HPT） promotes the lighter components in asphalt binder more easily fill to the SBS phase. The low-temperature flexibility of SBS+HPT composite modified asphalt is not deteriorated， its 70 ℃ tan δ is significantly reduced， its fatigue life is greatly increased， and its self-healing performance is enhanced. The ethylene stearic acid amide without end group treatment（HPT-E）， which only contains the amino group， can enhance the interaction between asphalt molecules. The tan δ of SBS+HPT-E composite modified asphalt at 70 ℃ is slightly less than 2， and its fatigue and self-healing performance are also improved. The ethylene stearic acid amide treated by ammonia removal（HPT-R） only contains carbonyl， which slightly increases the network density of polymer phase. The low-temperature flexibility of SBS+HPT-R composite modified asphalt is improved while the 70 ℃ tan δ is slightly decreased. The fatigue life of SBS+HPT-R composite modified asphalt is similar to that of the SBS modified asphalt， the self-healing performance is enhanced.