沥青混合料动态拉压特性对比

Comparisons on Dynamic Tension and Compression Characteristics of Asphalt Mixture

建立了再生沥青混合料单轴拉伸动态模量试验方法,设计了与之配套的夹具,对5种混合料进行拉伸和压缩两个方向动态模量试验,对比分析了动态模量、相位角及移位因子动态拉压不对称性。结果表明:压缩动态模量大于拉伸动态模量,拉伸方向相位角和移位因子均大于压缩方向;随着RAP掺量增加,压拉动态模量比增加,再生沥青混合料拉压模量不对称性增强;动态拉压不对称性表现出时温依赖性,压拉模量比和相位角差值随着频率的减小而变大。研究结论可为再生沥青路面结构设计中材料参数取值提供参考和借鉴。

A test method for the dynamic modulus of recycled asphalt mixture in uniaxial tension is established,and a fixture is designed.The dynamic modulus of 5 mixtures are tested in two directions of tension and compression.The dynamic modulus,phase angle and shift factor are compared and analyzed.The results show that:the compressive dynamic modulus is greater than the tensile dynamic modulus,and the phase angle and shift factor in the tensile direction are greater than that in the compressive direction.With the increase of RAP content,the dynamic modulus ratio of compressive tension increases,and the asymmetry of tensile modulus of reclaimed asphalt mixture increases.The dynamic tension asymmetry is time-temperature-dependent,and the tension modulus ratio and phase angle difference increase with decreasing frequency.The research results can provide reference for the material parameter value in the structural design of recycled asphalt pavement.