Effects of hydroxyethyl methyl cellulose ether on the hydration and compressive strength of calcium aluminate cement
- 12 Downloads
Aluminate containing phases such as tricalcium aluminate (C3A) and dodecacalcium heptaaluminate (C12A7) play a key role in the reaction between Portland cement and cellulose ether. In order to simplify such impact from calcium aluminate, calcium aluminate cement (CAC) was applied as a carrier. Effects of hydroxyethyl methyl cellulose ether (HEMC) on the hydration of CAC were characterized by means of isothermal calorimetry, X-ray diffraction analysis, thermal analysis and scanning electron microscopy, respectively. Meanwhile, the setting times, water retention, air content and compressive strengths of HEMC modified CAC pastes or mortars were also determined. Results indicate that HEMC prominently delays the hydration of CAC within 1 day, and the higher dosage of HEMC, the longer setting times. HEMC exerts no obvious impact on the formation amount of CAH10, only leads to a smaller crystal size. From aspect of physical and mechanical properties, the addition of HEMC improves the water retention of fresh CAC mortars, and only with addition of 0.1% HEMC, the water retention of fresh CAC mortars almost approaches 100%. Additionally, the addition of HEMC also significantly promotes the air content of fresh CAC mortars, leading to an obvious decrease in the compressive strengths.
KeywordsHEMC Calcium aluminate cement Hydration evolution Compressive strength
This work was supported by the National Key Technology R&D Programs of China (2016YFB0303503), the National Natural Science Fund of China (51608382), State Key Laboratory of Solid Waste Reuse for Building Materials (SWR-2017-003) and Fundamental Research Funds for the Central Universities.
- 5.Ma BG, Ou ZH, Jian SW, Xu RL. Influence of HEMC on the formation process of hydration products in cement pastes at early ages. J Build Mater. 2011;14(6):798–802. https://doi.org/10.3969/j.issn.1007-9629.2011.06.015.CrossRefGoogle Scholar
- 11.Ciobanu C, Iluc S, Lazau I, Pacurariu C. Some physico-mechanical properties of dry mortars containing cellulose ethers. Rev Rom Mater. 2011;41(1):30–41.Google Scholar
- 20.Coarna M, Georgescu M, Puri A, Diaconu D. ESCA, MIP and mechanical characterization of some Portland cement—methyl-cellulose composites. Key Eng Mater. 2004;264–268:2153–6. https://doi.org/10.4028/www.scientific.net/KEM.264-268.2153.CrossRefGoogle Scholar
- 23.Müller I. Influence of cellulose ethers on the kinetics of early Portland cement hydration [Dissertation]. Karlsruhe: University of Karlsruhe; 2006.Google Scholar
- 24.Knapen E. Microstructure formation in cement mortars modified with water-soluble polymers [Dissertation]. Leuven: Catholic University of Leuven; 2007.Google Scholar
- 29.Yuan RZ. Cementitious material science. Wuhan: Wuhan University of Technology Press; 1996.Google Scholar