Work was conducted under a larger experimental program investigating the effects of processing additions on the performance of portland cements in concrete mixtures. One of the findings of this work is that there appears to be a trend that increasing tricalcium aluminate and the alkali content of the cement clinker increases the risk of freeze–thaw damage when tests are done in the laboratory. This trend was observed in mixtures with adequate air void systems and similar compressive strengths. It is possible that this effect is due to the increased osmotic pressures set up by increasing alkali contents in the pore solutions.