沥青混合料永久变形累积损伤特性研究

Research on Cumulative Damage Characteristics of Permanent Deformation of Asphalt Mixture

为了研究沥青混合料永久变形累积损伤特性,选取AC—13沥青混合料进行三轴重复荷载永久变形试验,以修正Burgers模型为基础,将三单元范德普模型与外置黏壶串联构建沥青混合料黏弹性力学模型;以Weibull函数分布描述沥青混合料黏弹性损伤过程,并将损伤变量引入黏弹性力学模型的非线性串联粘壶中,建立了沥青混合料的黏弹性损伤本构模型,拟合相关系数在0.99以上。研究结果表明,不同温度阶段,沥青混合料重复荷载永久变形规律不同,建议从全温度条件综合考虑;温度和应力是影响沥青混合料永久变形损伤程度的关键因素,温度越高,应力越大,其损伤变量越大;黏弹性蠕变损伤力学模型能较好的描述沥青混合料三阶段的永久变形特性,在考虑荷载作用时间和全温域拟合效果方面具有明显优势,为进一步研究沥青路面永久变形预估提供支撑。

In order to study Cumulative damage characteristics of Permanent deformation of asphalt mixture, AC-13 asphalt mixture is selected for triaxial repeated load permanent deformation test, based on modified Burgers model, Viscoelastic material mechanics model of asphalt mixture was constructed by three unit model Depp model and external clay pot, which are connected in series; viscoelastic damage of asphalt mixture with Weibull distribution is described and the damage variable is introduced into nonlinear series clay pot of the nonlinear viscoelastic model, the viscoelasticity of the asphalt mixture damage constitutive model is established, and the correlation coefficient is above 0.99. The results show that the different temperature stages, the repeated load permanent deformation of asphalt mixture is different, comprehensive consideration of temperature conditions is recommended; temperature and stress is affecting asphalt mixture permanent deformation damage degree of key factors, the higher the temperature is, the greater the stress is,the greater the damage varies ; Viscoelastic creep damage mechanics model can better describe permanent deformation characteristics of asphalt mixture in the three phase, obvious advantages in considering load effect time and full temperature field fitting effect, for further study permanent deformation prediction of asphalt pavement to provide support.