膨润土改性水泥土力学特性试验研究

Experimental Study on Mechanical Properties of Cement Soil Modified by Bentonite

为对沿江地铁基坑进行防渗加固处理,利用膨润土与水泥对该工程区砂土进行改性。对不同掺量情况下的改性水泥土试块进行室内力学实验,得出随膨润土与水泥掺量变化改性水泥土强度参数与变形参数的变化规律。试验结果表明,膨润土的掺入会减弱水泥的水化反应,导致水泥土抗压强度、弹性模量降低;同时,膨润土的掺入也引起膨润土改性水泥土的抗剪强度参数降低。针对改性水泥土的力学性能变化,探讨了水泥土力学性能变化的原因,为优化膨润土改性水泥土材料的工程性质提供了可靠的实验依据。

In order to carry out anti-seepage reinforcement treatment on the foundation pit of Yanjiang subway,the sand in the project area was modified by bentonite and cement.The indoor mechanical experiments of modified cement soil test blocks under different dosages were carried out,and the variation law of strength parameters and deformation parameters of cement-soil modified with bentonite and cement content was obtained.The test results show that the incorporation of bentonite will weaken the hydration reaction of cement,resulting in the decrease of compressive strength and elastic modulus of cement soil.At the same time,the incorporation of bentonite also causes the shear strength parameters of bentonite modified cement soil to decrease.Aiming at the change of mechanical properties of modified cement soil,the reasons for the change of mechanical properties of cement soil were discussed,which provided a reliable experimental basis for optimizing the engineering properties of bentonite modified cement soil materials.