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Advances in Materials Science and Engineering
Volume 2014, Article ID 970298, 12 pages
http://dx.doi.org/10.1155/2014/970298
Research Article

Influence of Styrene-Acrylic Ester Dispersion on the Early Hydration of Cement

Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education, School of Materials Science and Engineering, Tongji University, 4800 Cao’an Road, Shanghai 201804, China

Received 20 May 2014; Accepted 16 July 2014; Published 11 August 2014

Academic Editor: Jaehwan Kim

Copyright © 2014 Ru Wang and Xiaoxin Shi. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Early hydration of cement in the presence of styrene-acrylic ester (SAE) dispersion was investigated, and the hydration heat, hydration degree, and hydrates were analyzed using isothermal calorimeter, XRD, and ESEM. The results show that SAE dispersion prolongs the induction period, postpones and shortens the accelerating period, and inhibits the decelerating and stable periods of cement hydration. The hydration heat and hydration degree of cement in the presence of SAE dispersion are less than those of the control. SAE dispersion inhibits the formation of C4AH13 and thus AFt, and more SAE dispersion brings stronger influence, but it enhances the stability of AFt. AFt generation during the early hydration period is controlled gradually by the reaction of C4AH13 generation with increasing SAE dispersion, but this is controlled by the reaction of C4AH13 consumption for the control paste. Besides, SAE dispersion retards and inhibits the formation of CH and C-S-H and also changes their morphology.