为了准确描述纤维沥青混凝土的粘弹性变形性能,在分析其蠕变全过程变形特征和常用粘弹性模型的基础上,提出了纤维沥青混凝土五单元八参数粘弹性力学模型。通过不同纤维体积率和长径比的纤维沥青混凝土小梁弯曲蠕变试验,求解模型参数,研究纤维体积率和长径比对模型参数及沥青混凝土粘弹性能的影响,建立了五单元八参数模型表征的考虑纤维含量特征参数影响的纤维沥青混凝土粘弹性本构方程,并进行了粘弹性分析。研究结果表明:五单元八参数模型能表征纤维沥青混凝土蠕变全过程的粘弹性变形特征,与蠕变试验结果具有较好的相关性;纤维含量特征参数能综合反映纤维体积率和长径比对沥青混凝土粘弹性能的影响,在所研究的试验范围内,纤维沥青混凝土最佳纤维体积率为0.348%,长径比为324,纤维含量特征参数为1.128。
In order to accurately describe the viscoelastic deformation behavior of fiber reinforced asphalt concrete, the viscoelastic mechanical model with five units and eight parameters for fiber reinforced asphalt concrete was put forward, based on the analysis of its whole process creep deformation behavior and common viscoelastic models. Through the creep tests on asphalt concrete beams with polyester fibers of different volume ratios and aspect ratios, the parameters in the model were solved, and the influence of fiber volume ratio and fiber aspect ratio on parameters of the model and viscoelastic performance of asphalt concrete were studied. Finally, the viscoelastic constitutive equation of asphalt concrete with the influence of fiber content characteristic parameters considered was established for viscoelastic analysis. The results show that the new model has a good relationship with the results of creep experiment, and can better characterize the fiber reinforced asphalt concrete's viscoelastic deformation characteristics of the whole creep process. The fiber content characteristic parameters can comprehensively reflect the influence of the fiber volume ratio and fiber aspect ratio on the viscoelastic behavior of asphalt concrete, and within the scope of the test in this article, the optimum fiber volume ratio in asphalt concrete is 0. 348%, the optimum fiber aspect ratio is 324 and the optimum fiber contentcharacteristic parameter is 1. 128.