The chemo-rheological properties of crumb rubber modified bitumen are always unstable due to the mutable and uncontrollable swelling-degradation degree of crumb rubber in bitumen matrix. The study aimed at exploring the continuous swelling and degradation behaviors of crumb rubber modified bitumen (CRMB) considering the influence of rubber size through monitoring the dynamic viscosity changes of CRMB binders. Moreover, the synergistic effects of swelling-degradation degree and rubber size on the chemical and rheological properties of CRMB were investigated. The results revealed that the rubber size significantly influenced the swelling and degradation behaviors of CRMB. The reduction of rubber size shortened the equilibrium swelling and degradation time, while increased the related viscosity dramatically. Moreover, during the degradation process, the decrease of rubber size could accelerate the continuous swelling rate, increase the maximum viscosity and reduce the continuous swelling time of CRMB. Meanwhile, the high swelling degree and large rubber size were beneficial to enhance the high temperature properties, while the CRMB binder with high degradation degree showed the better low-temperature property, workability and wider Newtonian flow region. Furthermore, the degradation degree promoted the formation of free hydroxide groups, aldehydes, carboxylic acids and esters, while the swelling process increased the average molecular weight of whole liquid phase in CRMB binder. The outputs from this fundamental study are beneficial to provide the guidance to preparation conditions optimization of CRMB binders with different viscous property standards.

由于胶粒在沥青基体中的溶胀降解程度多变且不可控，因此胶粒改性沥青的化学流变性能始终不稳定。该研究旨在通过监测 CRMB 粘合剂的动态粘度变化，探索考虑橡胶尺寸影响的碎胶改性沥青 (CRMB) 的连续溶胀和降解行为。此外，还研究了溶胀降解程度和橡胶尺寸对 CRMB 化学和流变性能的协同作用。结果表明，橡胶尺寸显着影响CRMB的溶胀和降解行为。橡胶粒径的减小缩短了平衡溶胀和降解时间，同时显着增加了相关粘度。此外，在降解过程中，橡胶粒径的减小可以加快CRMB的连续溶胀速度，增加最大粘度，减少连续溶胀时间。同时，高溶胀度和大的橡胶粒径有利于提高高温性能，而降解度高的CRMB粘合剂则表现出更好的低温性能、可加工性和更宽的牛顿流动区。此外，降解程度促进了游离羟基、醛、羧酸和酯的形成，而溶胀过程增加了 CRMB 粘合剂中整个液相的平均分子量。这项基础研究的成果有利于为不同粘度标准的 CRMB 粘合剂的制备条件优化提供指导。