- Author
-
Rossington, D. R.
|
Struble, L. J.
- Title
- Adsorption of High-Range Water-Reducing Agents on Selected Portland Cement Phases and Related Materials.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
New York State College of Ceramics, Alfred, NY
- Report
-
NISTIR 89-4172
September 1989
27 p.
- Distribution
- Available from National Technical Information Service
- Keywords
-
portland cements; plasticizers; water reducing agents; adsorption; concretes; silicate cements; chemical reactions; silica materials; slumping; hydration; chemical analysis
- Abstract
- The quantities of high-range water-reducing agents (superplasticizer) absorbed from their aqueous solutions by portland cement, tricalcium silicate, silica fume, wollastonite, and calcium silicate hydrate gel were determined using an ultraviolet spectrophotometer. The two superplasticizers (sulfonated melamine formaldehyde and sulfonated naphthalene formaldehyde) produced generally similar results. Wollastonite, a calcium silicate that does not react with water, produced no measurable adsorption of superplasticizer. The adsorption of superplasticizer by tricalcium silicate was similar to the adsorption by portland cement. From these results, it appears that superplasticizer is not absorbed by anhydrous silica or anhydrous calcium silicate, but rather by calcium silicate hydrate gel. Additional studies are recommended for improving the understanding of the absorption of superplasticizer by portland cement.