Effect of Silica Fume with Hydrated Lime on Compressive Strength and Carbonation Rate of C25 Concrete

Document Type : Original Article


1 Assistant Professor, Department of Civil Engineering, Shams Gonbad University

2 M. Sc. Of Structural Engineering, Department of Civil Engineering, Faculty of Engineering, Gonbad Kavous, Iran


In this study 11 different combinations of micro fly ash and calcium oxide were replaced instead of cement. Fly ash with 5%, 10%, 15% and 20% of cement and calcium oxide with 5%, 10%, 15% and 20% of cement and then a combination with fixed 15% fly ash and 5%, 10% and 15% of calcium oxide are replaced instead of cement. Then 108 sample of cubic concrete have been prepared and samples at the ages of 7, 28 and 56 days were applied compression strength and ultra sound tests and results were recorded and compared. According to the results, the samples had the best results at 56 days. The reason for the good results at 56 days was the entry of pozzolan into the system and its reaction with calcium hydroxide resulting from the hydration reaction.


[1]-Berry, E. E., and Malhotra, V. M., 1980, Fly Ash for Use in Concrete –A Critical Review, Journal of American Concrete Institute, March-April, 59-73.
[2]-Erdogan, T. Y., 1996, High-Lime Fly Ash Concretes, Proceedings, Cairo First International Conference on Concrete Structures, Vol.1, Jan 1996, 4-1 to 4-9
[3]- Lam, L., Wong, Y. L. and Poon, C. S., 1998, Effects of Fly Ash and Silica Fume on Compressive and Fracture Behavior of Concrete, Journal of Cement and Concrete Research, 28, 271-283.
[4]- Tarun, R., Bruce, W., 1990, High Early Strength Fly Ash Concrete for Precast, PCI Journal, 35, 6, 72 to 78
[5]- Han, S. H., Kim, J. K., and Park, Y. D., 2003, Prediction of compressive strength of fly ash concrete by new apparent activation energy function, Cement and Concrete Research, 33, 965-971.
[6]-Yoon, Y. S., Won, J. P., Woo, S. K. and Song, Y. C., 2002, Enhanced Durability Performance of Fly Ash Concrete for Concrete-Faced Rockfill Dam Application, Cement and Concrete Research, 32, 23-30.
[7]-Alasali, M. M., and Malhotra, V. M., 2000, Concrete Solution for Sustainable Development, International Materials Journal, 97(1), 41-48.
[8]-Malhotra, V. M., 2002, High performance, high-volume fly ash concrete, Concrete International, 24(7), 30-34.
[9]- Baharavar, S., Simsek, O., 2013, Reinforcement of C25 concrete with metal fibers and fly ash and study of some concrete properties and its effect on the amount of carbonation of concrete, International Conference on Civil Engineering, Architecture and Sustainable Urban Development, Iran.