消石灰和砂砾改良红黏土对比试验研究  

Research on comparative tests of lime and gravel improved red clay

作　　者：刘攀[1,2] 李守德[1,2] 董薇[1,2] Liu Pan Li Shoude Dong Wei(Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering ,Hohai University ^Nanjing 210098 , China Jiangsu Research Center for Geotechnical Engineering Technology （ Hohai University） , Nanjing 210098 , China)

机构地区：[1]河海大学岩土力学与堤坝工程教育部重点实验室,江苏南京210098 [2]江苏省岩土工程技术工程研究中心(河海大学),江苏南京210098

出　　处：《能源与环保》2017年第5期24-28,共5页CHINA ENERGY AND ENVIRONMENTAL PROTECTION

基　　金：教育部博士点基金项目(20100094110002)

摘　　要：南方地区红黏土直接用作填料时,压实度很难达到要求,需要利用消石灰和砂砾对其进行改良。通过击实试验、液塑限试验和收缩试验,探讨了2种改良土的适用性。研究表明:红黏土中掺入较高含量的消石灰时,虽然收缩系数和缩限增加,但最优含水率升高,液限和塑性指数均有所降低,土体的渗透性降低,土体的收缩开裂现象得到了较好抑制;掺灰比例高于4%时,试验所用红黏土可以达到很好的改良效果;红黏土中掺入砂砾后,最优含水率降低,最大干密度提高,土体的液限、塑限和塑性指数均降低,掺砂对红黏土液限的影响大于对塑限的影响,土体的收缩系数和缩限均得到降低,收缩开裂现象也得到了一定的抑制。试验所用红黏土最优掺砂比为20%,既可以达到改良效果,又具有较好的经济效益。As red clay in south China is used for filling,it is hard to fulfill the demand of compaction,so it is necessary to use the lime and gravel,which can improve the characteristics of the mixture. In this paper,the applicability of two kinds of modified soil was dis-cussed by compaction test,liquid plastic limit test and shrinkage test. The results show that,when incorporating higher level of lime,al-though the shrinkage factor and shrinkage limit increases, the optimum moisture content raises, liquid limit and plasticity index decrea- ses,permeability of the soil reduces,soil shrinkage cracking phenomenon has been well suppressed. When using red clay mixed with ash ratio higher than 4% ,a good effect to improve it can be achieved. When incorporating gravel,the optimum water content decreases,the maximum dry density increases, plastic limit and plasticity index decreases soil liquid limit, and the influence of red clay mixed with sand on the liquid limit is greater than the impact on plastic limit, the shrinkage limit and the contraction coefficient of soil are reduced, soil shrinkage cracking phenomenon has been also well suppressed. The optimum sand mixing ratio of red clay used in this experiment is 20% which can not only achieve the improvement effect but also have good economic benefit.

关 键 词：改性土 红黏土 消石灰 砂砾 路基 

分 类 号：TU441.2[建筑科学—岩土工程]