Laboratory tests on enhancing strength of cement stabilized organicsoil with addition of phosphor gypsum and calcium almninate cement  

磷石膏-高铝水泥双掺增强水泥固化有机质土强度室内试验研究（英文）

作　　者：Zhang Dingwen Liu Ziming Sun Xun Cao Zhiguo 

机构地区：[1]School of Transportation, Southeast University, Nanjing 210096, China [2]Sihong County Transportation Board, Sihong 223900, China

出　　处：《Journal of Southeast University(English Edition)》2017年第3期301-308,共8页东南大学学报（英文版）

基　　金：The National Natural Science Foundation of Chin(No.51578148);the Project of China Communications Construction(No.2015-ZJKJ-26);the Fundamental Research Funds for the Centra Universities,the Scientific Innovation Research of College Graduates in Jiangsu Province(No.SJLX15_0062)

摘　　要：In order to improve the engineering properties oforganic soil, a new stabilization agent is developed by theaddition of phosphor gypsum and calcium aluminate cement.The artificial organic soil is applied in the study and a series oflaboratory tests were carried out to explore new stabilizationagents and determine the optimal dosage. Unconfinedcompressive strength （UCS） and the pH value of soil poresolution were measured. The influence of organic content,agent composition and curing time on the UCS of sampleswere also researched. The test results show that the UCS ofstabilized organic soils by a new agent achieves approximately800 and 1 200 kPa at 28 and 90 d curing time, respectively.The pH test results show that a high alkaline environment is anecessary and not a sufficient condition for high strength. Thestrength of stabilized soil is related to the hydration product ofstabilization agent. The mechanism of strength formation wasalso explored by X-ray diffraction （XRD）, mercury intrusionporosimetry （MIP） and scanning electron microscope （SEM）tests. A large amount of ettringite is produced to fill the largepores of organic soils, which contribute to the high UCS valueof stabilized organic soils. The new agent can solidify theorganic soil successfully as well as provide a new approach totreat the organic soil.In order to improve the engineering properties of organic soil, a newstabilization agent is developed by the addition of phosphor gypsum and calcium aluminate cement.The artificial organic soil is applied in the study and a series of laboratory tests were carried out to explore newstabilization agents and determine the optimal dosage. Unconfined compressive strength( UCS) and the pH value of soil pore solution were measured. The influence of organic content,agent composition and curing time on the UCS of samples were also researched. The test results showthat the UCS of stabilized organic soils by a newagent achieves approximately800 and 1 200 kP a at 28 and 90 d curing time, respectively.The pH test results showthat a high alkaline environment is a necessary and not a sufficient condition for high strength. The strength of stabilized soil is related to the hydration product of stabilization agent. The mechanism of strength formation was also explored by X-ray diffraction( XRD), mercury intrusion porosimetry( MIP) and scanning electron microscope( SEM)tests. A large amount of ettringite is produced to fill the large pores of organic soils, which contribute to the high UCS value of stabilized organic soils. The newagent can solidify the organic soil successfully as well as provide a newapproach to treat the organic soil.

关 键 词：organic soil stabilization STRENGTH ETTRINGITE 

分 类 号：N0[自然科学总论—科学技术哲学]