Rice-husk ash paste and concrete: Some aspects of hydration and the microstructure of the interfacial zone between the aggregate and paste
- CANMET, Ottawa, Ontario (Canada). Natural Resources Canada
This paper presents an experimental study on the effects of the incorporation of rice-husk ash (RHA) in cement paste and concrete on the hydration and the microstructure of the interfacial zone between the aggregate and paste. The influence on the compressive strength of concrete is discussed, and the results are compared with those obtained with the control portland cement concrete and concrete incorporating silica fume. As for ordinary portland cement paste, it was found that calcium hydroxide and calcium silicate hydrates [C-S-H] were the major hydration and reaction products for the HA paste. Because of the pozzolanic reaction, the paste incorporating RHA had lower Ca(OH){sub 2} content than the control portland cement paste. The incorporation of the RHA in concrete reduced its porosity and the Ca(OH){sub 2} amount in the interfacial zone; the width of the interfacial zone between the aggregate and the cement paste was also reduced compared with the control portland cement composite. However, the porosity in the interfacial zone of the rice-husk ash composite was higher than that of the silica fume composite. The incorporation of the RHA in the cement paste did not increase its compressive strength compared with that of the control. The higher compressive strength of the RHA concrete compared with that of the control is due probably to the reduced porosity, reduced Ca(OH){sub 2}, and reduced width of the interfacial zone between the paste and the aggregate.
- OSTI ID:
- 276765
- Journal Information:
- Cement and Concrete Research, Vol. 26, Issue 6; Other Information: PBD: Jun 1996
- Country of Publication:
- United States
- Language:
- English
Similar Records
Performance of rice husk ash produced using a new technology as a mineral admixture in concrete
Characteristics of a thermally activated alumino-silicate pozzolanic material and its use in concrete