基于MSCR试验的改性沥青高温性能评价

High Temperature Performance Evaluation of Modified Asphalts Based on Multiple Stress Creep Recovery Test

摘要:

应用多应力蠕变恢复（MSCR）试验，对SBS改性沥青、胶粉改性沥青和高强沥青在不同温度下的不可恢复蠕变柔量Jnr与应力敏感性指标Jnrdiff进行了分析，依据AASHTO MP1910标准对3种改性沥青进行了交通分级，并采用改性沥青混合料三轴动态蠕变试验进行了验证.结果表明：在非线性范围内应力和温度对改性沥青抗永久变形能力的影响具有等效性；随着温度的升高，改性沥青流变性能的线性范围逐渐变窄，应力敏感性更为显著；胶粉改性沥青在低应力区间的高温性能优秀，但是其线性范围很小，当应力或温度提高时胶粉改性沥青的流变性能迅速进入非线性范围，高温性能急剧衰减；不同应力和温度下改性沥青高温性能的排序发生改变，基于AASHTO MP1910标准的交通分级能够反映改性沥青的这一特性.

Abstract:

Styrene butadiene styrene copolymer(SBS) modified asphalt, rubber modified asphalt and high strength asphalt were characterized using multiple stress creep recovery(MSCR) test at different temperatures. Non recoverable creep compliance(Jnr) and stress sensitivity index(Jnr diff) were analyzed. According to AASHTO MP19 10 specification, traffic grading of the three modified asphalts was conducted. Triaxial dynamic creep test of modified asphalt mixtures was used to verify it. The results show that the effects of stress and temperature on the resistance to permanent deformation of the modified asphalt in the nonlinear region are equivalent. As the temperature increases, the liner range of the modified asphalt gradually narrows, and its stress sensitivity is more significant. The rubber modified asphalt has excellent high temperature performance in the low stress range, but its linear range is very small. When the stress or temperature increases, the rubber modified asphalt rapidly reaches the non linear region, and its high temperature performance quickly degrades. The ordering of the resistance to permanent deformation from modified asphalts under different stresses and temperatures is diverse, and the traffic grade based on AASHTO MP19 10 specification can reflect this characteristics of the modified asphalt.