Is sheer thenardite attack impotent compared with cyclic conversion of thenardite-mirabilite mechanism in laboratory simulation tests?

► Sodium sulfate damage was partly contributed by thenardite in the standard tests. ► Thenardite alone could induce damage without any conversion to mirabilite. ► Cyclic conversion of thenardite-mirabilite was more destructive than sheer thenardite. ► Test duration played a role in evaluating the damage potency of thenardite.