Effect of polymer latexes with cleaned serum on the phase development of hydrating cement pastes

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• 作者：Xiangming Kong^a ; ^{kxm@mail.tsinghua.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Joachim Pakusch^b ; Daniel Jansen^c ; ^{Daniel.Jansen@fau.de" class="auth_mail" title="E-mail the corresponding author} ; Sebastian Emmerling^b ; Juergen Neubauer^c ; Friedlinde Goetz-Neuhoeffer^c
• 关键词：Hydration (A) ; Retardation (A) ; Latex (D) ; Cement (D) ; X-ray diffraction (B)
• 刊名：Cement and Concrete Research
• 出版年：2016
• 出版时间：June 2016
• 年：2016
• 卷：84
• 期：Complete
• 页码：30-40
• 全文大小：2925 K

文摘

The effects of polymer latexes on cement hydration were investigated by the combination of isothermal calorimetry, in-situ XRD and Cryo-SEM. Two model latexes with varied amounts of anionic charges were used for measurements after cleaned by dialysis to remove the serum components. This study confirms that in-situ XRD technique can be successfully adapted to hydrating cementitious systems in the presences of polymer latexes to quantitatively follow evolution of mineral phases involved in cement hydration. Results show that both polymers retard aluminate reaction and depress silicate reaction, by delaying the dissolution of C₃A, anhydrite and gypsum and consequently the formation of ettringite, and reducing the dissolution of C₃S and the formation of C-S-H. The anionic colloidal polymers exhibit more pronounced retardation effect on aluminate reaction than on silicate reaction due to stronger electrostatic interaction between the polymer particles and the positively charged aluminate phases. The more charged latex shows stronger retardation.