This paper uses a heterogeneous micromechanical model to evaluate the resistance to thermal cracking in bituminous composites containing granular particulates. Thermal cracking is mainly caused by temperature fluctuations leading to accumulated stress that exceeds the strength of the materials. The presence of various granular particulates significantly affects a material's strength and capacity to release stress. Here, we use a two-dimensional heterogeneous numerical finite element model to evaluate and predict the thermal cracking characteristics of bitumen containing granular particulates such as crumb rubber and taconite. To develop the model, randomly distributed polygons using the Delaunay triangulation method were used to represent taconite and crumb rubber inside a bitumen matrix. The elastic properties of taconite and crumb rubber were assigned to the particulates, and the viscoelastic properties of the bitumen were modeled using a Prony series by implementing a simple fractional viscoelastic model. The study results showed that the flexural creep stiffness and creep rate calculated by the model were in good agreement with the measurements of experiments: the maximum errors were 6.15% for bitumen containing crumb rubber and 13.72% for bitumen containing taconite. Considering that flexural creep stiffness and creep rate are commonly used as indicators of thermal cracking resistance, the newly developed heterogeneous micromechanical model can be used to evaluate the thermal cracking resistance of bituminous matrices containing granular particulates. The model was further used to study the effects of temperature, elasticity, and concentration of particulates on the cracking resistance of the bituminous matrix. For instance, it was found that introducing 16% particulates with an elasticity of 1.02 MPa (representing crumb rubber) to bitumen improves its critical cracking temperature from −25 °C to −29.3 °C. This model provides insights to help the design of bituminous composites with desired cracking resistance properties by incorporating the proper particulates.

本文使用异质微力学模型来评估含粒状颗粒的沥青复合材料的抗热裂性。热裂纹主要是由温度波动引起的，该温度波动导致累积的应力超过材料的强度。各种颗粒状颗粒的存在会显着影响材料的强度和释放应力的能力。在这里，我们使用二维非均质数值有限元模型来评估和预测沥青中含有粒状颗粒（如粒状橡胶和ta石）的热裂解特性。为了开发该模型，使用Delaunay三角剖分方法随机分布的多边形代表了沥青基体内的石和碎橡胶。将滑石粉和橡胶碎屑的弹性特性分配给颗粒，并通过实施简单的分数粘弹性模型，使用Prony系列对沥青的粘弹性特性进行建模。研究结果表明，该模型计算得到的挠曲蠕变刚度和蠕变速率与实验测量值吻合良好：含沥青胶粒的最大误差为6.15％，含con石胶质的沥青的最大误差为13.72％。考虑到弯曲蠕变刚度和蠕变速率通常用作抗热裂性的指标，因此新开发的异质微力学模型可用于评估包含颗粒状颗粒的沥青基质的抗热裂性。该模型还用于研究温度，弹性，和颗粒浓度对沥青基质抗裂性的影响。例如，发现在沥青中引入弹性为1.02 MPa的16％颗粒（代表碎橡胶）可将其临界开裂温度从-25°C提升至-29.3°C。该模型提供了一些见识，可通过掺入适当的颗粒来帮助设计具有所需抗裂性能的沥青复合材料。