多尺度条件下高弹高黏改性沥青耐老化及存储稳定性诊断评价

Diagnostic of aging resistance and storage stability of high performance modified asphalts under multi-scale conditions

为探究高性能添加剂对传统改性沥青抗老化行为的增强机制及其存储稳定性的影响特征,在掌握高弹高黏改性沥青基本物理性能参数的基础上,通过傅里叶红外光谱仪、动态剪切流变仪、荧光显微镜等多尺度测试手段,分析了不同老化状态下高弹高黏改性沥青的宏观流变力学行为及其微结构组成与形貌特征.结果表明:改性剂能够对传统改性沥青的基本物理性能有显著改善,残留针入度、软化点增量和残留延度等指标能够较好地评价沥青的耐老化性;傅里叶红外光谱中没有新出现的特征峰,表明沥青改性过程中以物理共混为主,羰基官能团指数、亚砜基官能团指数和聚合物指数能有效反映不同改性沥青的老化程度;通过动态剪切流变频率扫描试验获取的相位角、车辙老化指数及复数模量主曲线能够有效评价不同老化程度下沥青的流变力学行为;不同添加剂在传统改性沥青内部的分散、相容与交联状态存在差异,显著影响其内部的3维空间网状结构,进而导致其呈现不同的存储稳定性;以热塑性橡胶为主要成分的添加剂增强了传统改性沥青的耐老化能力及存储稳定性能.研究成果可为高性能添加剂的甄选及先进沥青基材料的生成与调控提供理论依据与技术保障.

It was aimed to explore the enhancement mechanism and the influence characteristics of the high-performance additives for the anti-aging behaviors and the storage stability of the traditional modified asphalts,the fundamental physical parameters,the macroscopic rheological mechanical behaviors.The microstructure compositions and the morphology characteristics of modified asphalts with characteristics of high-elasticity and high-viscosity were analyzed under different aging conditions through the multi-scale test methods such as the Fourier transform infrared spectroscopy,dynamic shear rheology and fluorescence microscopy.The results showed that the additives could significantly improve the fundamental physical properties of traditional modified asphalts,and the indexes including residual penetration,softening point increment and residual elongation could appropriately evaluate the aging resistance of asphalts.No new characteristic peak generated in the FTIR spectrum proved that the physical blending dominates the asphalt modification process,and the carbonyl functional group index,sulfoxide functional group index and polymer index could effectively reflect the aging degree of various modified asphalts.The phase angle,the rutting aging index and the complex modulus principal curves obtained through the dynamic shear rheological frequency scanning test could effectively estimate the rheological behaviors of asphalts under different aging degrees.The distinction features such as dispersion,compatibility and cross-linking indicated that various additives in traditional modified asphalts could significantly affect the three-dimensional spatial network structure of traditional modified asphalts,and further resulted in the different storage stability.The additives mainly composed by the thermoplastic rubber could enhance the aging resistance and the storage stability of traditional modified asphalts.The research results provided theoretical basis and technical support for the selection of high-performance additives and the generation and control of advanced asphalt base materials.