Sulfate Resistance of Concrete Pavers

Abstract

The sulfate resistance of concrete pavers was determined using a method based on ASTM C 1012. Specimens were submerged in a 5% sodium sulfate solution for a period of one year. Length change and loss in mass were determined. Effect of mixture proportions on sulfate resistance, and relationships between expansion, mixture proportions, and concrete bulk properties are presented and analyzed. In addition, the expansion of the test specimens is compared to proposed acceptance limits found in the literature. Test results showed that the concrete pavers had excellent sulfate resistance, even above that expected when using moderate sulfate-resisting ASTM C 150 type II cement. Sulfate resistance was found to be directly related to the aggregate-cement ratio of the mixture and bulk properties of the concrete. The continued expansion measured throughout the experiment and the absence of any visual signs of softening appear to indicate that the principal factor in the sulfate attack was the in-situ formation of ettringite.