考虑沥青混合料空隙率的蠕变特性及改进Burgers模型

为了更为精确的分析不同空隙类型沥青混合料的抗变形性能的影响，在经典的Burgers模型上进行改进，添加了一个非线性元件，得到改进的Burgers模型，将模型的宏观参数转化为离散元PFC的微观参数，植入PFC程序，用于分析不同空隙特征沥青混合料的抗变形性能。结果表明：改进Burgers模型能较好地表征空隙率较大的沥青混合料的蠕变特性，且空隙率较大的沥青混合料在加载过程中相比与空隙率较小的沥青混合料的非线性蠕变变形更为明显，同时，改进Burgers模型可较好地预测在不同温度条件下不同空隙类型的沥青混合料的蠕变变形。用于研究大空隙特征沥青混合料OGFC-13时，当空隙率增大2%时，沥青混合料蠕变变形最大可增大1/2,当空隙率增大10%时，沥青混合料蠕变变形可增大近6倍。

Creep characteristics considering porosity of asphalt mixture and Modified Burgers model

In order to more accurately analyze the influence of the anti-deformation performance of asphalt mixtures with different pore characteristics, the classic Burgers model is modified in this paper, a nonlinear element is added, and the modified Burgers model is obtained. The macroscopic parameters of the model are converted into the microscopic parameters of discrete element PFC, and the PFC program is implanted to analyze the deformation resistance of asphalt mixtures with different pore characteristics.The results show that the modified Burgers model can better characterize the creep characteristics of asphalt mixtures with larger porosity, and the nonlinear creep deformation of asphalt mixtures with larger porosity is more obvious during loading.At the same time, the improved Burgers model can better predict the creep deformation of asphalt mixtures with different pore types under different temperature conditions.When the asphalt mixture OGFC-13 is used to study the characteristics of large pores, when the porosity increases by 2%, the creep deformation of the asphalt mixture can increase by 1/2 at most. When the porosity increases by 10%, the creep deformation of the asphalt mixture can increase nearly 6 times..