有机质对水泥改良红黏土的力学特性影响及微观机理分析

Effect of Organic Matters on Mechanical Properties of Cement Treated Red Clay and its Micro-mechanism

红黏土中有机质含量是影响水泥土力学特性的重要因素。通过开展不同有机质含量下水泥改良红黏土的强度试验,探究了水泥红黏土中有机质对其变形及力学特性的影响效应;此外,结合SEM与XRD微观测试试验,探析了水泥改良红黏土中有机质的内在影响机理。结果显示,在一定含量范围内试样的粘聚力随有机质含量的增加有所提升,而试样的无侧限抗压强度与内摩擦角均持续减小直至接近影响临界值;在微观层面上,有机质通过抑制试样中水化产物的生成以及诱导其结构形态的转变,进而影响水泥红黏土的宏观力学特性。

The organic content in the red clay is an important factor affecting the engineering performance of cement treated soils.By testing the mechanical strength of the treated red clay with different organic content,the effect of organic matter on the deformation and strength properties of the treated red clay was evaluated.The mechanism of organic matter in the cementtreated red clay was analyzed by the Scanning Electronic Microscope(SEM)and X-Ray Diffraction tests.The results show that,within the organic content studied,the tested sample cohesion increases with the organic content,while the unconfined compressive strength and internal friction angle of the sample continue to decrease until close to the critical value of organic content.At the microscopic level,the organic content affects the mechanical properties of the cement treated red clay by inhibiting the formation of hydration products and inducing the transformation of its structure and morphology.