水泥复合偏高岭土稳定粉砂土力学特性试验研究

Experimental Study on Mechanical Properties of Cement Composite Metakaolin Stabilized Silty Sand Soil

使用低成本高硅铝矿物掺合料可在提升水泥土工程性能的同时降低水泥用量。通过开展系列抗压强度试验研究了水泥偏高岭土掺比、水/水泥偏高岭土比、凝胶总掺量和养护龄期对水泥复合偏高岭土稳定粉砂土抗压强度的影响规律,归纳了水泥复合偏高岭土稳定粉砂土的强度经验公式。结果表明:将水泥和偏高岭土按质量比5∶1混合用于粉砂土稳定时可获得最佳强度提升,节约1/6水泥消耗,且该掺比关系不因凝胶总掺量变化而改变;水泥复合偏高岭土稳定粉砂土抗压强度随水/水泥偏高岭土比增加近似线性降低,随凝胶总掺量增加线性提升,随龄期发展而提高,其28天强度增加趋势仍未趋缓;总结归纳了四个关于强度影响因素的经验预测公式。该研究成果可为水泥偏高岭土用于复合稳定工程软弱土提供理论参考。

The use of low-cost high silicon aluminum mineral admixtures can improve the engineering performance of cementitious soil while reducing the amount of cement used.Through a series of compressive strength tests,the influence of cement metakaolin ratio,water/cement metakaolin ratio,total gel content and curing age on the compressive strength of cement composite metakaolin stabilized silt was studied,and the empirical strength formula of cement composite metakaolin stabilized silt was summarized.The results show that when cement and metakaolin are mixed at a mass ratio of 5:1 to stabilize silty soil,the best strength increase can be achieved and 1/6 of cement consumption can be saved,and the mixing ratio relationship does not change with the change of total gel content.The compressive strength of cement composite metakaolin stabilized silty sand decreases approximately linearly with the increase of water/cement metakaolin ratio,increases linearly with the increase of total gel content,and increases with the development of age.The 28 day strength increase trend has not yet slowed down.Four empirical prediction formulas for strength influencing factors have been summarized.The research results can provide theoretical reference for the use of cementitious metakaolin in composite stable engineering soft soil.