AC-13级配钢渣沥青混合料粘弹塑本构模型研究

为了研究钢渣沥青混合料非线性粘弹塑性变形特性,提出Schapery模型与改进Swchartz模型组合的积分型粘弹塑本构模型。采用钢渣替换AC-13级配中粒径2.36 mm以上的石灰石粗骨料,制作得到钢渣沥青混合料试件。设计并开展一系列的单轴压缩蠕变实验,通过应力递增蠕变回复实验,获得不同应力条件下材料的弹性、粘弹性应变和粘塑性应变,进而拟合确定本构模型参数。利用0.4 MPa、1.0 MPa下的蠕变回复实验验证模型有效性。结果表明,模型不仅能准确刻画钢渣沥青混合料蠕变过程中的弹性、粘弹性与粘塑性变形,还可用于预测不同应力水平下钢渣沥青混合料蠕变变形规律。

Research on Visco-Elastoplastic Constitutive Model for AC-13 Graded Asphalt Mixture with Steel Slag

Based on the coupling of Schapery viscoelastic model and modified Swchartz viscoplastic model, an integral constitutive model was proposed to study the characterization of nonlinear visco-elastoplastic deformation of asphalt mixture with steel slag. The specimens of AC-13 gradation were fabricated, while the limestone coarse aggregate sizes larger than 2.36 mm were replaced by steel slag. A series of uniaxial compressive creep tests were designed and conducted. The elastic, viscoelastic and viscoplastic strains under different stresses were decomposed from multiple-stress repeated creep-recovery test. And then the parameters in the model were fitted and determined. The capability of the constitutive models was verified by the creep recovery tests under 0.4 MPa and 1.0 MPa. The result shows that the proposed model not only accurately describes the deformation of elastic, viscoelastic and viscoplastic behavior of steel slag asphalt mixture during the creep recovery behaviour, but also be able to predict the creep recovery deformation rule of asphalt mixture with steel slag with different stress levels.