Resistance of plain and blended cement mortars exposed to severe sulfate attacks

To emphasize the effect of physical sulfate attack on pozzolanic additions, the resistance of plain and blended cement mortars was investigated using 10% Na2SO4 and MgSO4 solutions under four exposure regimes which included the standard conventional exposure and field-like exposures that created the physical sulfate attack. Although the performance of blended cement mortars was observed to be better under a conventional exposure regime, the damage in blended cement mortars was more severe under the exposure regimes that promoted the physical sulfate attack in a Na2SO4 environment. However, the physical attack by MgSO4 was not apparent. Overall, MgSO4 was found to be more damaging than Na2SO4 from the aspect of chemical attack; however Na2SO4 was more harmful than MgSO4 as far as the physical attack is considered.