Compressive strength and sulfate resistance properties of concretes containing Class F and Class C fly ashes

This paper presents the results of an experimental investigation carried out to evaluate compressive strength and sulfate resistance properties of concrete mixtures in which Turkish Class C and Class F fly ashes were partially replaced with cement. A total of 39 mixtures with different mix designs were prepared. Compressive strength tests were carried out and the mixtures with similar compressive strength values were used for sulfate resistance tests. The degree of sulfate attack was evaluated using expansion and weight loss tests. Compression test results indicate that the concrete mixture with Class C fly ash showed higher compressive strength than that with Class F fly ash. Moreover, regardless the fly ash type, the addition of fly ash significantly increased the resistance to sulfate attack.