掺加RAP的骨架密实型级配碎石性能

    Performance of Coarse Graded Unbound Granular Materials Containing RAP

    • 摘要: 为了解决沥青路面回收料(reclaimed asphalt pavement,RAP)在级配碎石中应用的问题,研究了RAP对骨架密实型级配碎石性能的影响.在室温(22℃)条件下,采用UTM-100对纯碎石及掺加RAP的骨架密实型级配碎石进行了动态模量、抗剪强度和永久变形对比试验.依据试验结果,分析了RAP对级配碎石性能的影响.研究表明,掺加RAP后,骨架密实型级配碎石动态回弹模量显著增大,平均增幅9.3%,模量增幅受围压和偏压围压比不同程度的影响,其中偏压围压比的影响较围压更为显著.抗剪强度有所减小,且应力软化阶段应力下降速率较慢.在发生剪切破坏时,与不掺加RAP的级配碎石具有相似的剪胀特征.轴向永久变形随RAP的加入显著增大,表明抵抗永久变形能力有所下降.

       

      Abstract: In order to solve the problem of the application of reclaimed asphalt pavement (RAP) in unbound granular materials, an investigation into the effect of RAP on the performance of coarse graded unbound granular materials was conducted. A series of laboratory tests used UTM-100 including the repeated load triaxial test, the quick shear test and the permanent deformation test were performed on coarse graded UGMs containing RAP as well as UGMs of neat virgin aggregates at room temperature(22 ℃).The effect of RAP on the performance of unbound granular materials was analyzed in accordance with the experimental results.The test results show that after adding RAP, the dynamic resilient modulus of coarse graded unbound granular materials increase obviously, and the average growing rate is 9.3%. The growing rate is affected by confining pressure and the ratio of bias to confining pressure. And the ratio of bias to confining pressure has more significant influence. The shear strength decrease and the decreasing rapid is slower in stress softening stage. When shear failure occurs, coarse graded unbound granular materials have similar dilatancy effect. Axial permanent deformation increases distinctly, which shows material's resistance to permanent deformation declined.

       

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