为了保证水泥土挤密桩在冬季施工过程中桩体水泥土不被冻胀破坏,在低温环境下进行了水泥土挤密桩水泥土强度试验,试验在符合要求的土料中按不同水泥用量(6％,8％,10％)同时掺入不同细度要求的2％生石灰粉和不同比例(0.15％,0.25％)的元明粉分别配制土样,在-10℃低温环境条件下1～3 h后成型,在6～8℃和10 ～13C环境下养护,养护完成后逐一进行强度试验.试验结果表明,8％水泥用量,掺入400目或200目2％生石灰粉和0.15％,0.25％元明粉均可以满足1.3 MPa设计强度要求；从降低成本角度,推荐采用单掺0.20％ ～0.25％元明粉配制的水泥土,可以满足设计和规范规定的强度要求,且施工操作更简便.%For the purpose of avoiding frost-heave damage of the cement soil of cement soil compaction piles during construction in winter, strength tests on their cement soil under low-temperature environment are carried out. The samples are prepared by use of the satisfactory soil materials, among which, the cement at a percentage of 6% , 8% , 10% is mixed with 2% quicklime powder with different finenesses and sodium sulphate with different proportions of 0. 15% and 0. 25% . The soil samples are molded under - 10℃ for 1-3 hours and then cured under 6-8℃ and 10-13℃ , respectively. The strength tests are performed after they are cured. The results show that the design strength requirement of 1.3 MPa can be satisfied by mixing the cement at a percentage of 8% with the 2% quicklime powder with 400- or 200-mesh and the sodium sulphate with proportions of 0. 15% and 0. 25% . From the viewpoint of cost analysis, the cement soil prepared only by use of the sodium sulfate with proportions of 0. 20% -0. 25% can meet the design and specification strength requirements, and its construction process is much simpler.
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