Freeze–thaw resistance and chloride-ion penetration of cement-stabilized clay exposed to sulfate attack

• Effects of sulfate attack and freeze-thaw action on cement stabilised clay were investigated.
• Ordinary portland cement (PC) and sulfate resisting cement (SR) were used.
• Strength and chloride ion penetration of specimens were determined.
• Freeze-thaw resistance and sulfate resistance of specimens were improved by cement usage.
• SR bearing mixtures showed better performance than mixtures containing PC.

It is well known that existence of sulfate in groundwater has adverse effects on strength and permeability of cement stabilized clay. On the other hand, freeze/thaw action also causes a reduction in strength and a subsequent increase in permeability of cement stabilized clay. However, a study concerning the coupled effects of these two phenomena is not encountered in the literature. Therefore, in this study, effects of sulfate attack and freeze–thaw action on strength and penetrability properties of cement stabilized kaolin were investigated within an experimental framework. The results revealed that the use of sulfate resistant cement is more feasible than the use of ordinary Portland cement, when cement stabilized clay is exposed to subsequent effects of freeze–thaw action and sulfate attack. Evidence from test results also proved that, irrespective of cement type, freeze–thaw resistance of cement stabilized clay specimens exposed to sulfate attack was lower than those of sulfate-free specimens. The results including the effects of cement inclusion level, sulfate salt type, curing period, and number of freeze–thaw cycles were presented in detail. Finally, empirical relationships among unconfined compressive strength, freeze–thaw cycles, cement content and curing period were established.