Zhao Jia, Zhao Weigang, Xie Kaize, Yang Yong
School of Civil Engineering, Shijiazhuang Tiedao University, Shijiazhuang 050043, China.
School of Safety Engineering and Emergency Management, Shijiazhuang Tiedao University, Shijiazhuang 050043, China.
Materials (Basel). 2023 Sep 8;16(18):6131. doi: 10.3390/ma16186131.
In order to improve the accuracy and universality of the nonlinear viscoelastic-plastic mechanical behavior characterization method of asphalt mixture, a new criterion for the division of the creep process of materials was established based on the strain yield characteristics, and the coexistence mechanism of Viscoelastic-Viscoplastic strain was proposed in the subsequent yield phase; then, a viscoelastic element was constructed in the form of a parallel connection of two fractional viscoelastic elements based on fractional calculus theory, and its mathematical equations were derived; with novel viscoelastic elements, a constitutive model characterizing the whole creep process of asphalt mixtures was developed and its analytical expression was derived. The laboratory short-term creep test of Cement and Asphalt Mortar (CA mortar) and the simulation test data of asphalt mixtures from the references were used to verify the constitutive model. The results show that the creep constitutive model of asphalt mixture established in this paper has excellent fitting accuracy for different phases of the creep process of asphalt mixture under different stress levels, where the minimum fitting correlation values R for CA mortar, asphalt mixture (applied to pavement engineering), and asphalt sand are 0.9976, 0.981, and 0.979, respectively. Therefore, this model can be used to provide a theoretical reference for the study of the characterization of the mechanical behavior of asphalt materials.
为提高沥青混合料非线性粘弹塑性力学行为表征方法的准确性和通用性，基于应变屈服特性建立了材料蠕变过程划分的新准则，并提出了后续屈服阶段粘弹性 - 粘塑性应变的共存机制；然后，基于分数阶微积分理论，以两个分数阶粘弹性元件并联的形式构建了一个粘弹性元件，并推导了其数学方程；利用新型粘弹性元件，建立了表征沥青混合料整个蠕变过程的本构模型并推导了其解析表达式。采用水泥乳化沥青砂浆（CA砂浆）的室内短期蠕变试验以及参考文献中沥青混合料的模拟试验数据对本构模型进行验证。结果表明，本文建立的沥青混合料蠕变本构模型对不同应力水平下沥青混合料蠕变过程的不同阶段具有优异的拟合精度，其中CA砂浆、（应用于路面工程的）沥青混合料以及沥青砂的最小拟合相关系数R分别为0.9976、0.981和0.979。因此，该模型可为沥青材料力学行为表征的研究提供理论参考。
