Alkaline stability of cellulose ethers and impact of their degradation products on cement hydration

• Published in: Cement and concrete research Vol. 36; no. 7; pp. 1252 - 1256
• Main Authors: Pourchez, J., Govin, A., Grosseau, P., Guyonnet, R., Guilhot, B., Ruot, B.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Ltd 01.07.2006; Elsevier Science; Elsevier
• Subjects: Alkaline degradation; Applied sciences; Building failures (cracks, physical changes, etc.); Buildings. Public works; Calcium binding capacity; Cellulose ethers; Cement concrete constituents; Cements; Chemical and Process Engineering; Complex; Delay; Durability. Pathology. Repairing. Maintenance; Engineering Sciences; Exact sciences and technology; Hydration; Materials; Properties of anhydrous and hydrated cement, test methods; Alkaline degradation; Calcium binding capacity; Delay; Cellulose ethers; Complex; Stability; Hydration; Experimental study; Material weathering; Degradation; Binding capacity; Cement; Cellulose ether; calcium binding capacity; alkaline degradation; delay; cellulose ethers; complex
• ISSN: 0008-8846; 1873-3948
• DOI: 10.1016/j.cemconres.2006.03.028

Cellulose ethers are polymers frequently introduced into mortar formulations. This study allows to assess the potential role of cellulose ethers degradation on the alteration of the cement hydration kinetics. A retardation mechanism based on the calcium binding capacity of chelates is often proposed to describe the effects of some polysaccharides (e.g. sugars) on cement hydration. The alkaline stability of cellulose ethers has been poorly studied and may represent one way to understand the hydration delay induced by such admixtures. Identification and quantification of the hydroxy carboxylic acids generated during alkaline degradation were performed. The results indicate that cellulose ethers are very stable in alkaline media. We also show that the ability of cellulose ethers to complex calcium ions is negligible. Finally, degradation of cellulose ethers and its impact on the cement hydration kinetics does not seem to be significant.