不同吸水环境下碱渣固化淤泥毛细吸水和强度性质  

Capillary Water Absorption and Strength of Soft Soil Solidified with Soda Residue Under Different Water Environments

作　　者：何俊 罗时茹 龙思昊 朱元军 HE Jun;LUO Shiru;LONG Sihao;ZHU Yuanjun(School of Civil Engineering,Architectural and Environment,Hubei University of Technology,Wuhan 430068,China)

机构地区：[1]湖北工业大学土木建筑与环境学院,武汉430068

出　　处：《材料导报》2024年第9期143-148,共6页Materials Reports

基　　金：国家自然科学基金(41772332)。

摘　　要：地下水位以上的固化淤泥中存在毛细吸水现象,可能会对固化淤泥的耐久性产生不利影响。以碱渣、矿渣和电石渣对淤泥进行固化处理,开展不同吸水环境下固化淤泥的毛细吸水、无侧限抗压强度、X射线衍射和核磁共振试验,研究毛细传输系数和强度的变化规律及其微观机理。研究表明,固化淤泥毛细管系数与吸水系数之比为2.3~3.2;固化淤泥的吸水系数和毛细管系数随碱渣掺量的增加先减后增,在碱渣掺量为25%(质量分数,下同)时最小,对应毛细孔体积也最小;随着水中含盐量增加,更多的钙矾石生成并发生氯化钠的迁移和聚集,毛细孔体积增多,孔径增大,毛细吸水能力增强,导致固化淤泥的毛细吸水系数和毛细管系数增大,无侧限抗压强度降低。在海水环境下毛细吸水使碱渣固化淤泥强度损失比水泥固化淤泥更严重。以碱渣等工业固体废弃物作为淤泥固化剂时,需考虑毛细吸水对固化淤泥耐久性的不利影响。Capillary water absorption occurs in solidified soft soil above the groundwater level,which may have an adverse impact on durability of solidified soil.The soft soil was solidified with soda residue(SR),ground granulated blast furnace slag and carbide slag.The capillary water absorption,unconfined compressive strength(UCS),X-ray diffraction and nuclear magnetic resonance tests of solidified soil under different water absorption environments were carried out to study the variation of capillary transport coefficient and strength and its microscopic mechanism.The results show that the ratio of capillary coefficient(κ)to capillary sorptivity(s)are in the range of 2.3 to 3.2.The s andκof solidified soil decrease at first and then increase with the increase of SR content,and the minimum s andκvalues and capillary pore volume occur at 25%SR content.With the increase of salt concentration,more ettringite is generated and sodium chloride migrates and aggregates.Accordingly,the volume of capillary pores and the capillary absorption capacity of solidified soil increase,which contributes to the increase of s andκvalues and the decrease of UCS.The decrease in UCS at seawater environment for SR solidified soil is greater than that for cement solidified soil.It is necessary to pay attention to the adverse effect of capillary absorption on durability of soil solidified with industrial solid wastes such as SR.

关 键 词：碱渣固化淤泥 毛细吸水 吸水环境 毛细水传输系数 无侧限抗压强度 

分 类 号：TU443[建筑科学—岩土工程]