摘要
橡胶沥青的微观悬浮结构使得施工黏度高,进而造成耗能、污染和性能变异等工程应用难题,胶粉的微纳分散有助于形成微观胶体结构,可以有效解决这一瓶颈,因而有必要探索施工黏度的多尺度依赖性。通过分析不同降解胶粉所制备橡胶沥青的组成、聚集态和分子链等多尺度微观结构,研究了胶粉的降解程度、掺量和改性剂类型对降解胶粉改性沥青黏度的影响,以及黏度对剪切速率和温度的敏感特性。结果表明,胶粉的预先降解提高了其在沥青中的分散程度,增加了基体中溶胶含量,减小了凝胶颗粒的含量和尺寸,使黏度随胶粉降解程度的提高而下降。加工黏度随降解胶粉含量的增加而增加,当降解橡胶含量为35%时,凝胶颗粒接触成网,降解胶粉改性沥青的黏度急剧上升。降解胶粉改性沥青具有明显的流变学剪切敏感特性,温度敏感性相对减弱。深度降解胶粉/SBS复合改性沥青兼具较高的切敏性和温敏性。工程应用中可采用升温和提高剪切速率(振动频率)结合的方式来提高橡胶沥青的施工和易性。
The suspension system of rubberized asphalt causes high processing viscosity,leading to energy consumption,pollution and variation in engineering application.The pre-degradation of crumb rubber promoting the formation of colloid structure can significantly reduce the viscosity of rubberized asphalt.However,the viscosity as function of size of crumb rubber is still unclear.In this study,the effects of degradation degree,dosage of rubber and modifier type on the viscosity of degraded rubber modified asphalt,and the sensitivity of viscosity to shear rate and temperature were studied by analyzing the multi-structure of rubberized asphalts including its composition,morphology and molecular chain.Results show that the preprocessing(degradation)of rubber improves its dispersion in asphalt,increases the content of sol in the matrix,and decreases the content and size of gel particles,leading to the decreased viscosity with the increase of the degradation degree of rubber.Moreover,the viscosity of rubberized asphalt increases with the increase of the content of rubber.As the content is 35%,the gel particles contact with each other and form a net,the viscosity sharply rises.The degraded rubber modified asphalt has obvious rheological shear sensitivity and relatively weakened temperature sensitivity.In addition,the deeply degraded rubber/SBS hybrid modified asphalt has high shear sensitivity and temperature sensitivity.Accordingly,the processibility of rubberized asphalt could be improved by the combination of heating and increasing shear rate(vibration frequency)in engineering applications.
作者
于晓晓
王珊珊
俞炜
王仕峰
Xiaoxiao Yu;Shanshan Wang;Wei Yu;Shifeng Wang(School of Chemistry and Chemical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;Shanghai Road and Bridge Group Co.LTD,Shanghai 200433,China)
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
2024年第3期1-11,共11页
Polymer Materials Science & Engineering
基金
科技部重点研发计划(2021YFE0105200)。
关键词
橡胶沥青
降解胶粉
加工性能
黏度
流变
rubberized asphalt
degraded rubber
processibility
viscosity
rheology
