Influence of polymer on cement hydration in SBR-modified cement pastes
- Key Laboratory of Advanced Civil Engineering Materials, Ministry of Education, School of Materials Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092 (China) and Institute of Cement-Based Materials, School of Materials Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092 (China)
- Key Laboratory of Advanced Civil Engineering Materials, Ministry of Education, School of Materials Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092 (China)
The influence of styrene-butadiene rubber (SBR) latex on cement hydrates Ca(OH){sub 2}, ettringite, C{sub 4}AH{sub 13} and C-S-H gel and the degree of cement hydration is studied by means of several measure methods. The results of DSC and XRD show that the Ca(OH){sub 2} content in wet-cured SBR-modified cement pastes increases with polymer-cement ratio (P/C) and reaches a maximum when P/C is 5%, 10% and 10% for the pastes hydrated for 3 d, 7 d and 28 d, respectively. With wet cure, appropriate addition of SBR promotes the hydration of cement, while the effect of SBR on the content of Ca(OH){sub 2} and the degree of cement hydration is not remarkable in mixed-cured SBR-modified cement pastes. XRD results illustrate that SBR accelerates the reaction of calcium aluminate with gypsum, and thus enhances the formation and stability of the ettringite and inhibits the formation of C{sub 4}AH{sub 13}. The structure of aluminum-oxide and silicon-oxide polyhedron is characterized by {sup 27}Al and {sup 29}Si solid state NMR spectrum method, which shows that tetrahedron and octahedron are the main forms of aluminum-oxide polyhedrons in SBR-modified cement pastes. There are only [SiO{sub 4}]{sup 4-} tetrahedron monomer and dimer in the modified pastes hydrated for 3 d, but there appears three-tetrahedron polymer in the modified pastes hydrated for 28 d. The effect of low SBR dosage on the structure of aluminum-oxide and silicon-oxide polyhedron is slight. However, the combination of Al{sup 3+} with [SiO{sub 4}]{sup 4-} is restrained when P/C is above 15%, and the structure of Al{sup 3+} is changed obviously. Meantime, the polymerization of the [SiO{sub 4}]{sup 4-} tetrahedron in C-S-H gel is controlled.
- OSTI ID:
- 20871575
- Journal Information:
- Cement and Concrete Research, Vol. 36, Issue 9; Other Information: DOI: 10.1016/j.cemconres.2006.05.020; PII: S0008-8846(06)00152-9; Copyright (c) 2006 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0008-8846
- Country of Publication:
- United States
- Language:
- English
Similar Records
Effect of hydration temperature on the solubility behavior of Ca-, S-, Al-, and Si-bearing solid phases in Portland cement pastes
Compatibility of hydrogarnet, Ca{sub 3}Al{sub 2}(SiO{sub 4}){sub x}(OH){sub 4(3−x)}, with sulfate and carbonate-bearing cement phases: 5–85 °C