酸碱固化剂共存条件下固化黏土力学行为特征分析

Analysis on Mechanical Behavior Characteristics of Stabilized Clay Under the Coexistence Condition of Acidic and Alkalic Additives

为探究酸碱固化剂共存条件对于固化黏土力学性能的影响规律,在分析基质黏土基本物性参数及酸碱固化剂固化机理的基础上,设计不同配合比固化土混合料,通过系列室内试验,开展了酸碱固化剂固化土混合料力学行为特征研究。结果表明:基质红黏土为低液限黏土,液态离子土壤固化剂具有强酸性,最佳掺入量为干土质量的0.014%;离子土壤固化剂独特的分子结构能够减小双电层结合水膜厚度,矿物颗粒密实度增强;离子土壤固化剂掺入后,各配合比混合料的7 d无侧限抗压强度均有不同程度的提升;除高石灰掺入量的固化土混合料外,压实度对离子土壤固化剂固化效果的发挥影响较大,需达到96%及以上;随着龄期增加,酸碱固化剂固化土的抗压强度、劈裂强度以及冻融性能持续提升,但由于酸碱中和反应以及离子土壤固化剂的油性膜效应,抑制了后期石灰水泥碳酸化、火山灰及水化反应进程,酸碱固化土强度演变特征存在固化叠加效应的优势体现期。

In order to study the influence of the coexistence condition of acidic and alkalic stabilizer on the mechanical performance of stabilized clay,on the basis of analyzing basic physical parameters of matrix clay and the stabilization mechanism of ionic and alkalic soil stabilizer,a research on the mechanical behavior characteristics of stabilized clay mixture which is stabilized by ionic and alkalic soil stabilizer is performed for the stabilized clay with different mix proportions by a series of laboratory tests. The result shows that（ 1） the matrix red clay is low liquid limit clay and the liquid ionic soil stabilizer has a strong acidity whose optimal content is 0. 014% mass ratio of the dry soil;（ 2） due to the unique molecular structure of ionic soil stabilizer,the thickness of the double electric combined water film becomes thin at the compaction molding process,which makes the clay particle structure compactness increased;（ 3） the 7 d unconfined compressive strengths of the different mixtures are improved to different degrees when the ionic soil stabilizer is jointed;（ 4） except for the high lime soil mixture,if the compaction degree of soil has a pronounced effect on stabilization performance of the ionic soil stabilizer,the least compaction degree should be more than 96%;（ 5） the compressive strength,the indirect tensile strength and the freeze-thaw performance of the acidic and alkali stabilized soils present a gradual increasing trend with the increasing of curing time,however,due tothe fact that the neutralization reaction and the oil membrane effect of ionic soil stabilizer inhibit the process of lime and cement＇s carbonation,volcanic ash and hydration reaction,the evolution characteristics of the strength of the stabilized clay exists an advantage emboding period of stabilization superposition effect.