Hostname: page-component-586b7cd67f-rcrh6 Total loading time: 0 Render date: 2024-11-25T17:28:53.805Z Has data issue: false hasContentIssue false
  • English
  • Français

Low Cement/High Fly Ash Concretes: Their Properties and Response to Chemical Admixtures

Published online by Cambridge University Press:  21 February 2011

V. H. Dodson
V. H. Dodson*
Affiliation:
Construction Products Division, W. R. Grace & Co., 62 Whittemore Avenue, Cambridge, MA 02140
Get access

Abstract

In practice, the amount of fly ash added to portland cement concrete varies depending upon the desired end properties of the concrete. Generally, when a given portland cement concrete is redesigned to include fly ash, between 10 and 50% of the cement is replaced by a volume of fly ash equal to that of the cement. Sometimes as much as twice the volume of the cement replaced, although 45.4 kg (100 lbs) of cement will only produce enough calcium hydroxide during its reaction with water to react with about 9 kg (20 lbs) of a typical fly ash. The combination of large amounts of certain fly ashes with small amounts of portland cement in concrete has been found to produce surprisingly high compressive strengths, which cannot be accounted for by the conventional “pozzolanic reaction”. Ratios of cement to fly ash as high as 1:15 by weight can produce compressive strengths of 20.7 MPa (3,000 psi) at I day and over 41.4 MPa (6,000 psi) at 28 days. Methods of identifying these “hyperactive” fly ashes along with some of the startling results, with and without chemical admixtures are described.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 113: Symposium Q – Fly Ash and Coal Conversion By-Products IV , 1987 , 199
Copyright
Copyright © Materials Research Society 1988

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Hubert, C.E., U. S. Patent No. 4 240 952, 23 December 1980.Google Scholar
2. Brewer, W.E., in Fourth International Ash Utilization Symposium, March 24, 1976, St. Louis, MO. pp. 422–431.Google Scholar
3. Zosel, S., Construction Bulletin, April, 1981, pp. 20–21.Google Scholar
4. Engineering News Record, October, 1980, pp. 16–17.Google Scholar
5. National Technical Information Service, Report No. 10, Miscellaneous Paper No. 6–123, August, 1962.Google Scholar
6. Hague, M.N., Langan, B.W., Ward, M.A., ACI Journal, Jan-Feb, 1984, pp. 54–60.Google Scholar
7. Naik, T.R. and Ramme, B.W., Cem. Concr.Res. 17, 283–294 (1987).Google Scholar
8. Dodson, V.H., Roberts, L.R., U.S. Patent No. 4 210 457, 1 July 1980.Google Scholar
9. ASTM C150–85a. Standard Specification for Portland Cement, American Society for Testing and Materials, Vol. 04.01, pp. 153–159 (1986).Google Scholar
10. ASTM C618–85, Standard Specification for Fly Ash and Raw or Calcined Natural Pozzolan for Use as a Mineral Admixture in Portland Cement Concrete, American Society for Testing and Materials, Vol. 04.02, pp. 385–388 (1986).Google Scholar
11. ASTM C204–84, Standard Test Method for Fineness of Portland Cement by Air Permeability Apparatus, American Society for Testing and Materials, Vol. 04.01, pp. 208–215 (1986).Google Scholar
12. ASTM C33–86, Standard Specification for Concrete Aggregate, American Society for Testing and Materials, Vol. 04.02, pp. 11–20 (1986).Google Scholar
13. ASTM C403–85, Standard Test Method for Time of Setting of Concrete Mixtures by Penetration Resistance, American Society for Testing and Materials, Vol. 04.02, pp. 323–333 (1986).Google Scholar
14. ASTM C494–86, Standard Specifications for Chemical Admixtures for Concrete, American Society for Testing and Materials, Vol. 04.02, pp. 323–333 (1986).Google Scholar
15. Dodson, V.H. in Effects of Fly Ash Incorporation in Cement and Concrete, edited by Diamond, S. (Mater. Res. Soc. Proc. N, Boston, MA, 1981) pp.18 4–193.Google Scholar
16. Dunstan, E.R. Jr., Cement. Concrete and Aggregates. ASTM Vol.2(6),1980, pp. 20–30.Google Scholar
17. ASTM C 114–83, Standard Methods for Chemical Analysis of Hydraulic Cement, American Society for Testing and Materials, Vol. 04.01, pp. 99–38, 1983.Google Scholar
18. Henisch, H.K., Crystal Growth in Gels, Pennsylvania State University Press, 1970.Google Scholar
19. ASTM Cl 86-86, Standard Test Method for Heat of Hydration of Hydraulic Cement, American Society for Testing and Materials, Vol. 04.01, pp. 185–191, 1986.Google Scholar