CTAB对不同蒙脱石含量粘土的工程特性影响研究

Influence of CTAB on engineering properties of clay with different montmorillonite contents

为研究表面活性剂CTAB对粘土的工程特性的影响,通过室内渗透、剪切、压缩与开裂试验,考察了表面活性剂对不同蒙脱石含量下粘土的渗透系数、抗剪力学参数、压缩系数的影响规律,基于裂隙率、节点个数、土块个数等指标,揭示了表面活性剂作用下粘土的开裂特性。试验结果表明:添加表面活性剂后粘土的渗透系数和抗剪强度均增大,压缩系数降低,其中蒙脱石含量为29.6%的粘土添加表面活性剂后渗透系数在10^(-8)cm/s级别;表面活性剂能降低粘土的开裂程度,当其溶液的浓度低于且最接近临界胶束浓度时,开裂抑制效果最为明显。试验结果为表面活性剂改性粘土做卫生填埋场覆盖层提供了技术参数。

In order to study the effect of surfactants ( CTAB ) on the engineering properties of clay , the influences of CTAB on the permeability coefficient, shear mechanical parameters and compression coefficient of the clay under different montmorillonite contents are investigated by using the laboratory osmosis test, shearing test, compression test and cracking test. Based on the fracture rate, node number and clod number, the cracking characteristics of the clay under the action of CTAB are revealed. The test results show that the permeability coefficient and the shear strength of the clay increase and the compression coefficient decrease after adding surfactants. The permeability coefficient of clay with 29. 6% montmorillonite content is about 10 8 cm/s. Meanwhile, CTAB can reduce the cracking degree of clay. When the concentration of the CTAB solution is lower and closest to the critical micelle concentration , the cracking inhibition effect is the most obvious. The test results provide technical parameters for the surfactant-modified clay to be used as the sanitary landfill cover.