应力状态对沥青混合料黏弹性质的影响

Effect of Stress State on Viscoelastic Properties of Asphalt Mixtures

利用不同条件下SMA13和Superpave20两种沥青混合料三轴复数模量试验结果,根据黏弹性理论关系式,确定了不同围压和温度条件下沥青混合料蠕变柔量的Prony系列表达式,并对其影响因素进行了分析.结果表明:随着围压的增加,沥青混合料的蠕变柔量减小,且这一效果在围压较小时更为明显;沥青混合料短期蠕变柔量随温度增加而增加,尤其当温度较低时,这一增加的幅度较大;当围压较低时,沥青混合料长期蠕变柔量随温度升高有较明显的增加,而围压较高时该增加趋势则不明显;随着围压和温度的增加,沥青混合料蠕变柔量更快地接近于其极限值.

Triaxial complex modulus test results of two asphalt mixtures, SMA13 and Superpave20, ob- tained at various conditions were converted to creep compliances according to viscoelastic theoretical rela-tionships. Influencing factors of creep compliance were investigated. The results show that creep compliance of asphalt mixtures decreases as confining pressure increases, and decrease of creep compliance is more evident at low temperatures. Short-term creep compliance increases with temperature and the magnitude of increase is larger at lower temperatures. Long-term creep compliance increases with temperature at low confining pressure, and the effect of temperature on long-term creep compliance become insignificant at high confining pressure. Creep compliance approaches the asymptote more quickly as confining pressure and temperature increase.