添加剂CCCW作用下硫铝酸盐水泥固化土耐MgSO_4侵蚀性能及早期强度模型

The Properties and Early Strength Model of SAC Solidified Soil Under MgSO_4 Erosion with CCCW

针对目前水泥固化土耐硫酸镁侵蚀性能研究多基于硅酸盐水泥的现状,以硫铝酸盐水泥固化土为对象,采用外蚀(成型后浸泡)和内蚀(制作时内掺)2种方式制作了试件,探讨了硫铝酸盐水泥固化土在硫酸镁溶液侵蚀下的早期强度发展规律。通过等量替换的方式,研究了水泥基渗透结晶型防水材料(CCCW)占用土质量4%时,其对硫铝酸盐水泥固化土耐硫酸镁侵蚀性能的影响。基于水泥固化土稳固系数理论,分别提出了硫酸镁溶液在2种侵蚀方式下的硫铝酸盐水泥固化土早期强度JM和NM模型,并对模型进行了检验。结果表明:硫铝酸盐水泥固化土在硫酸镁溶液侵蚀下,早期强度呈先上升后下降的趋势,浸泡1~3 d时强度增大较快,在7 d时达到最大,14 d时有较大下降;侵蚀方式对硫铝酸盐水泥固化土早期强度有较大影响,内蚀方式下强度一直呈上升趋势,且较外蚀方式高1~2 MPa;等量替换方式下,CCCW会降低硫铝酸盐水泥固化土强度,但提高了其耐硫酸镁侵蚀性能,MgSO_4溶液质量浓度为1.5~18.0 g/L时,2种侵蚀方式下14 d强度一直呈上升趋势;基于水泥固化土稳固系数的硫铝酸盐水泥固化土早期强度JM和NM模型具有一定的可行性,14 d时间内强度预测值与实测值误差最高分别为7.31%和5.07%。

Most of present studies on the properties about MgSO4erosion resistant of solidified soil were based on ordinary portland cement.Sulfur aluminate cement solidified soil was put as research object.By means of soaking MgSO4solutions and making specimen with MgSO4polluted water,the experiments were carried out to discuss the early strength performance of SAC solidified soil under MgSO4erosion.By the way of equal weight replace,the properties of SAC solidified soil under MgSO4erosion was discussed with4%(mass friction)cementitious capillary crystalline waterproofing materials(CCCW).According to the stability coefficient of cement solidified soil,the early strength JM and NM model were established under each erosion condition and inspected by the way of fitting.The results show that the unconfined compressive strength(UCS)grows to the highest at7d curing time with a rapid growth in1~3days,while decreases fast in14days.The early strength of SAC solidified soil with4%(mass friction)CCCWconstantly grows in14days under two erosion conditions when the mass concentration of solution is between1.5g/L and18.0g/L.The error between predicted and test strength under early strength JM and NM model are7.31%and5.07%,respectively.The conclusions are that the early strength of SAC solidifiedsoil would increase first and then decrease and it is influenced deeply by erosion ways.By the way of equal weight replace,the early strength of SAC solidified soil decreases with CCCW while the resistant ability under MgSO4erosion is improved.The predicted strength is nearly closed to actual strength and it could be inferred that the JM and NM models are feasible.