Influence of Polyepoxysuccinic Acid on Solid Phase Products in Portland Cement Pastes  

作　　者：IIU Chengmu WANG Xiaoyan BAI Ruiying LIU Gang FENG Xiaoxin DING Qingjun 胡晨光;WANG Xiaoyan;BAI Ruiying;LIU Gang;FENG Xiaoxin;DING Qingjun(Hubei Key Laboratory of Roadway Bridge and Structure Engineering（WuhanUniversity of Technology）,Wuhan 430070,China;Col-lege of Materials Science and Engineering,North China University of Science and Technology,Tangshan 063210,China;Qing Gong Col-lege,North China University of Science and Technology,Tangshan 063000,China;School of Materials Science and Engineering,Wuhan University of Technology,Wuhan 430070,China)

机构地区：[1]Hubei Key Laboratory of Roadway Bridge and Structure Engineering(Wuhan University of Technology),Wuhan 430070,China [2]College of Materials Science and Engineering,North China University of Science and Technology,Tangshan 063210,China [3]Qing Gong College,North China University of Science and Technology,Tangshan 063000,China [4]School of Materials Science and Engineering,Wuhan University of Technology,Wuhan 430070,China

出　　处：《Journal of Wuhan University of Technology(Materials Science)》2018年第5期1140-1149,共10页武汉理工大学学报（材料科学英文版）

基　　金：Funded by the Major State Basic Research Development Program of China(973 Program)(No.2015CB655101);Hubei Key Laboratory of Roadway Bridge and Structure Engineering(Wuhan University of Technology)(No.DQZDJJ201504);State Key Laboratory of High Performance Civil Engineering Materials(No.2015CEM006);Natural Science Foundation of Hebei Province(No.E2016209283);Science and Technology Program of Hebei Province(No.16273706D)

摘　　要：The influence of polyepoxysuccinic acid（PESA）on the solid phase products in hydrated Portland cement pastes was investigated by isothermal calorimetry,X-ray diffraction（XRD）,^29Si and ^27Al nuclear magnetic resonance（NMR）.The results indicated that PESA bonds Ca^2＋ions in pore solution to prevent portlandite formation,and also combines with Ca^2＋ions on the surface of silicate minerals to prolong the control time of phase boundary reaction process,leading to the retardation of silicate mineral hydration.Meanwhile,the interlayer Ca^2＋ions in Jennite-like structure bridging PESA and C-S-H gels prevent silicate tetrahedron and aluminum tetrahedron from occupying the sites of bridging silicate tetrahedron,which causes the main existence of dimer in C-S-H structure,deceases the degree of Al^3＋substituting for Si^4＋and promotes the transformation from 4-coordination aluminum to 6-coordination aluminum.Furthermore,the-Ca^＋chelating group from reacting PESA with Ca^2＋ions combines easily with SO4^2-ions,resulting in transformation from ettringite,AFm to TAH（Third aluminum hydrate）.However,with the higher addition of PESA,it will bridge the excess PESA by Ca^2＋ions to form a new chelate with ladder-shaped double chains structure,which not only reduces the amount of PESA bonding Ca^2＋ions,but also decreases its solidifying capability for SO4^2-ions,leading to the transformation from TAH to AFm or ettringite.Meanwhile,at later hydration,the inhibition effect of PESA on cement hydration is weakened,and the transformation degree from TAH to AFm is higher than that to AFt with the addition of PESA.The influence of polyepoxysuccinic acid（PESA）on the solid phase products in hydrated Portland cement pastes was investigated by isothermal calorimetry,X-ray diffraction（XRD）,^29Si and ^27Al nuclear magnetic resonance（NMR）.The results indicated that PESA bonds Ca^2＋ions in pore solution to prevent portlandite formation,and also combines with Ca^2＋ions on the surface of silicate minerals to prolong the control time of phase boundary reaction process,leading to the retardation of silicate mineral hydration.Meanwhile,the interlayer Ca^2＋ions in Jennite-like structure bridging PESA and C-S-H gels prevent silicate tetrahedron and aluminum tetrahedron from occupying the sites of bridging silicate tetrahedron,which causes the main existence of dimer in C-S-H structure,deceases the degree of Al^3＋substituting for Si^4＋and promotes the transformation from 4-coordination aluminum to 6-coordination aluminum.Furthermore,the-Ca^＋chelating group from reacting PESA with Ca^2＋ions combines easily with SO4^2-ions,resulting in transformation from ettringite,AFm to TAH（Third aluminum hydrate）.However,with the higher addition of PESA,it will bridge the excess PESA by Ca^2＋ions to form a new chelate with ladder-shaped double chains structure,which not only reduces the amount of PESA bonding Ca^2＋ions,but also decreases its solidifying capability for SO4^2-ions,leading to the transformation from TAH to AFm or ettringite.Meanwhile,at later hydration,the inhibition effect of PESA on cement hydration is weakened,and the transformation degree from TAH to AFm is higher than that to AFt with the addition of PESA.

关 键 词：PESA cement pastes solid phase products formation Al3＋ coordination 

分 类 号：TU528[建筑科学—建筑技术科学]