土工格室加筋沥青混凝土单轴压缩过程细观特性研究

Study on the Microscopic Characteristics of Geocell-reinforced Asphalt Concrete During Uniaxial Compression

为探究压缩过程中土工格室加筋对沥青混凝土细观特性的影响,文中进行土工格室加筋与未加筋沥青混凝土的室内单轴压缩试验,得到室温(20℃)下应力-应变关系曲线。考虑粗骨料和土工格室的形态特征与沥青砂的黏弹特性,利用PFC3D软件构建加筋与未加筋沥青混凝土的细观数值模型,并通过室内试验中的应力-应变关系曲线标定模型参数,最后进行虚拟单轴压缩试验以评价土工格室加筋对沥青混合料压缩过程的影响。结果表明,压缩过程中土工格室加筋对粗骨料间接触力的影响并不显著,却会使沥青砂浆间的接触压力与接触拉力在低区间的分布降低,在高区间的分布上升,约束沥青混凝土的侧向位移。

In order to investigate the effect of geocell reinforcement on the fine-scale characteristics of asphalt concrete during compression,indoor uniaxial compression tests of geocell-reinforced and unreinforced asphalt concrete were carried out to obtain the stress-strain relationship curves at room temperature of 20℃.Considering the morphological characteristics of coarse aggregate and geocell and the viscoelastic properties of asphalt sand,PFC3D software was used to construct a fine-scale numerical model of reinforced and unreinforced asphalt concrete,and the model parameters were calibrated by the stress-strain relationship curves from the indoor tests,and finally a virtual uniaxial compression test was conducted to evaluate the effect of geocell reinforcement on the compression process of asphalt mixtures.The results of the study show that the effect of geocell reinforcement on the indirect contact force between coarse aggregates during the compression process is not significant,but it will cause the distribution of contact pressure and contact tension between asphalt mortar to decrease in the low range and increase in the high range,restraining the lateral displacement of asphalt concrete.