Influence of Polyepoxysuccinic Acid on Solid Phase Products in Portland Cement Pastes
来源期刊：Journal Of Wuhan University Of Technology Materials Science Edition2018年第5期
论文作者：胡晨光 WANG Xiaoyan BAI Ruiying LIU Gang FENG Xiaoxin DING Qingjun
文章页码：1140 - 1149
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 Ca2+ions in pore solution to prevent portlandite formation,and also combines with Ca2+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 Ca2+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 Al3+substituting for Si4+and promotes the transformation from 4-coordination aluminum to 6-coordination aluminum.Furthermore,the-Ca+chelating group from reacting PESA with Ca2+ions combines easily with SO42-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 Ca2+ions to form a new chelate with ladder-shaped double chains structure,which not only reduces the amount of PESA bonding Ca2+ions,but also decreases its solidifying capability for SO42-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.
胡晨光1,2，WANG Xiaoyan3，BAI Ruiying2，LIU Gang2，FENG Xiaoxin2，DING Qingjun4
1. Hubei Key Laboratory of Roadway Bridge and Structure Engineering (WuhanUniversity of Technology)2. College of Materials Science and Engineering, North China University of Science and Technology3. Qing Gong College, North China University of Science and Technology4. School of Materials Science and Engineering, Wuhan University of Technology
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 Ca2+ions in pore solution to prevent portlandite formation,and also combines with Ca2+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 Ca2+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 Al3+substituting for Si4+and promotes the transformation from 4-coordination aluminum to 6-coordination aluminum.Furthermore,the-Ca+chelating group from reacting PESA with Ca2+ions combines easily with SO42-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 Ca2+ions to form a new chelate with ladder-shaped double chains structure,which not only reduces the amount of PESA bonding Ca2+ions,but also decreases its solidifying capability for SO42-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.
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