This paper presents a mesoscale model to investigate the rubber particle effect on the mechanical properties of crumb rubber concrete (CRC). Taking Young’s modulus as an example, the short-term and long-term compressive behaviour of CRC with varying rubber percentages, shapes, and sizes were simulated. As the first step of the simulation, the Walraven equation was used to convert the 3D distribution of coarse aggregate and rubber particles in an actual specimen to a 2D distribution in a plane state. Then four differently shaped coarse aggregates and rubber particles including circular, elliptical, circle-derived polygonal, and ellipse-derived polygonal aggregate were generated. Based on an overlap judgement algorithm, Python programs were compiled to create a three-phase mortar-coarse aggregate-rubber CRC model and a two-phase concrete-rubber CRC model. All results from both models with varying particle shapes are within the range of experimental values. When the rubber content of CRC samples was 18%, the maximum deviation between the two-phase model and the three-phase CRC model was only 1.4%. Numerical results verified that incorporating rubber particles in concrete reduced material rigidity. The rubber percentage was the main influencing factor on the reduction rate of Young’s modulus of CRC, while the influence from varying crumb rubber particle shapes and sizes was ignorable. For practical applications, a prediction formula for Young’s modulus of CRC was provided. The proposed mesoscale model was also applied to the creep behaviour analysis of CRC, showing that the addition of crumb rubber particles had little effect on the creep coefficient of rubber concrete. The numerical results agreed well with the experimental study.

本文提出了一个中尺度模型来研究橡胶颗粒对橡胶粉混凝土 (CRC) 力学性能的影响。以杨氏模量为例，模拟了不同橡胶百分比、形状和尺寸的 CRC 的短期和长期压缩行为。作为模拟的第一步，使用 Walraven 方程将实际试件中粗骨料和橡胶颗粒的 3D 分布转换为平面状态的 2D 分布。然后生成四种不同形状的粗骨料和橡胶颗粒，包括圆形、椭圆形、圆形衍生的多边形和椭圆形衍生的多边形骨料。基于重叠判断算法，编译Python程序以创建三相砂浆-粗骨料-橡胶CRC模型和两相混凝土-橡胶CRC模型。具有不同颗粒形状的两种模型的所有结果都在实验值范围内。当CRC样品的橡胶含量为18%时，两相模型与三相CRC模型的最大偏差仅为1.4%。数值结果证实，在混凝土中掺入橡胶颗粒会降低材料刚度。橡胶百分比是影响CRC杨氏模量降低率的主要因素，而不同碎胶颗粒形状和尺寸的影响可以忽略不计。对于实际应用，提供了CRC杨氏模量的预测公式。所提出的中尺度模型也适用于 CRC 的蠕变行为分析，表明添加碎胶颗粒对橡胶混凝土的蠕变系数影响不大。数值结果与实验研究吻合良好。