Effect of water soluble PVA on the microstructure characteristics of C-S-H formed in Na₂SiO₃-Ca(NO₃)₂ solution system

Abstract

The structure characteristics of hydrated calcium silicate synthesized by solution reaction method with the existing of water soluble polymer polyvinyl alcohol (PVA) are investigated. Using Na₂SO₃ and Ca(NO₃)₂ as the main raw materials, in the condition of 2%(in weight) addition of PVA and the water to solid ratio of 20, hydrated calcium silicate samples (Ca/Si=1.0 and 1.5) were prepared with 60 °C water bath. IR, BET, XRD and SEM methods were used to study the microstructure of the hydration products. The results showed that the addition of water soluble PVA did not alter obviously the amorphous structure characteristic of hydrated calcium silicate, but it had effects on the polymerization status of Si-O chain and the pore structure. The effects are somewhat obvious in the samples with the Ca/Si of 1.0.

Keywords

C-S-H / polyvinyl alcohol / microstructure

References

[1] Chandra S., Flodin P. Interactions of Polymers and Organic Admixtures on Portland Cement Hydration[J]. Cem. Concr. Res., 1987, 17(6): 875-890.

[2] Larbi J. A., Bijen J. M. J. M. Interaction of Polymers with Portland Cement During Hydration: A Study of the Chemistry of the Pore Solution of Polymer-Modified Cement Systems[J]. Cem. Concr. Res., 1990, 20(1): 139-147.

[3] Ohama Y. Handbook of Polymer-Modified Concrete and Mortars, Properties and Process Technology[M], 1995 Park Ridge Noyes Publications

[4] Jenni A., Holzer L., Zurbriggen R., . Influence of Polymers on Microstructure and Adhesive Strength of Cementitious Tile Adhesive Mortars[J]. Cem. Concr. Res., 2005, 35(1): 35-50.

[5] Z Chen, M Tan. Progress of Polymer Concrete Composite[C]. Proceedings of the First East Asia Symposium Polymers in Concrete, Korea, 1994

[6] Knapen E., Van Gemert D. Cement Hydr a t ion and Microstructure Formation in the Presence of Water-Soluble Polymers[J]. Cem. Concr. Res., 2009, 39(1): 6-13.

[7] Beaudoin J. J., Dramé H., Raki L., . Formation and Characterization of Calcium Silicatehydrate-Hexadecyltrimethylam-Monium Nano Structure[J]. J. Mater. Res., 2008, 23(10): 2 804-2 815.

[8] Hu S. G. Studies on the Promotion Strength Mechanisms of the Role of Interfacial Bonding in Polymer Cement Based Composite Materials[D], 1992 Wuhan Wuhan University of Technology

[9] Minet J., Abramson S., Bresson B., . Organic Calcium Silicate Hydrate Hybrids: A New Approach to Cement Based Nanocomposites[J]. J. Mater. Chem., 2006, 16(14): 1 379-1 383.

[10] Matsuyama H., Young J. F. Intercalation of Polymers in Calcium Silicate Hydrate:A New Synthetic Approach to Biocomposites[J]. Chem. Mater., 1999, 11(1): 16-19.