This paper investigates the effect of clay content on the shear strength of clay–sand mixtures. Bentonite and Jumunjin sand were mixed to prepare clay–sand mixtures with varying clay contents of 5, 10, 15, 20, 25 and 30%. The shear strength of clay–sand mixture was measured using direct shear tests and angle of repose tests in dry condition. The angle of repose of the clay–sand mixture was measured to be greater than that of pure sand for the studied range of clay contents. Likewise, the internal friction angle of the clay–sand mixture was measured to be higher than that of pure sand, reaching a peak at the clay content of 10%. Theoretically, the behavior of the clay–sand mixtures was to be governed by large size particles at clay contents smaller than 23.5%, which agrees well with the visual inspection on the mixtures. At clay content of 25.1% or greater, where the contribution of large particle was theoretically assumed to be none, the results from the angle of repose tests were significantly scattered, indicating that the clay started playing a key role in the behavior of mixtures.

中文翻译：

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黏土含量对黏土混合物抗剪强度的影响

本文研究了粘土含量对粘土-砂混合物的剪切强度的影响。混合膨润土和Jumunjin砂以制备粘土含量为5、10、15、20、25和30％的粘土-砂混合物。使用直接剪切试验和休止角试验在干燥条件下测量粘土-砂混合物的剪切强度。在研究的粘土含量范围内，测得的粘土-砂混合物的休止角大于纯砂的休止角。同样，测得的粘土-砂混合物的内摩擦角高于纯砂的内摩擦角，在粘土含量为10％时达到峰值。从理论上讲，粘土-砂混合物的行为应由粘土含量小于23.5％的大尺寸颗粒控制，这与混合物的目视检查非常吻合。粘土含量为25时。