This study is part of an environmental experimental program on the use of scrap automobile tires for geotechnical applications. Different types of laboratory tests were conducted to determine the elastic, plastic, and creep parameters of tire derived aggregate (TDA)-sand granulated mixtures. However, this paper emphasizes the plasticity parameters via the development of a critical state model based on the results of triaxial tests. This was attained by considering loose sand specimens, at a predetermined TDA volumetric content, subject to three different confining pressures under a constant axial displacement rate. The calculated deviatoric stress versus axial strain curves, obtained via the modified Cam Clay model, captured the non-linear elastoplastic response obtained in the tests. Results indicated that the level of the shear strength is highly dependent on critical state friction angle which in turn depends on the TDA content. For the loose TDA-sand mixtures used in the present study, the effect of the TDA content demonstrates a reinforcement of the sand matrix. However this reinforcement diminishes as the TDA content increases.

这项研究是将废弃汽车轮胎用于岩土工程的环境实验计划的一部分。进行了不同类型的实验室测试，以确定轮胎衍生骨料 (TDA)-砂粒混合物的弹性、塑性和蠕变参数。然而，本文通过基于三轴试验结果开发临界状态模型来强调塑性参数。这是通过考虑在预定 TDA 体积含量下，在恒定轴向位移速率下承受三种不同围压的松散砂试样来实现的。通过修改的 Cam Clay 模型获得的计算偏应力与轴向应变曲线捕获了在测试中获得的非线性弹塑性响应。结果表明，剪切强度的水平高度依赖于临界状态摩擦角，而临界状态摩擦角又取决于 TDA 含量。对于本研究中使用的松散 TDA 砂混合物，TDA 含量的影响证明了砂基质的增强。然而，这种强化会随着 TDA 含量的增加而减弱。