Influence of fiber type and content on freeze-thaw resistance of fiber reinforced lime stabilized clay

In this paper, a comparison of influences of freeze-thaw action on lime stabilized basalt and polypropylene fiber reinforced clay was investigated. Specimens including 12 mm basalt and polypropylene fiber at 0, 0.5 and 1% contents by weight were compacted under standard Proctor effort at their optimum moisture contents. Some of the fiber-clay mixtures were stabilized with 3% of lime, the rest of specimens were free of lime, for comparison. All specimens were cured for 28 days in a moist room (relative humidity is 95 ± 2%) at an average temperature of 20 °C. After curing, specimens were subjected to 0, 1, 3, 7 and 10 cycles of freeze-thaw tests following ASTM procedure. A series of unconfined compression and ultrasonic pulse velocity tests were performed. Test results showed that increased application of freeze-thaw cycles caused a decrease in unconfined compressive strength and ultrasonic pulse velocity of all specimens. A linear correlation was observed between unconfined compressive strength and ultrasonic pulse velocity values. Besides, loss of mass in specimens after being exposed to freeze-thaw action was evident. Considering freeze-thaw resistance, it was understood that polypropylene fiber is more effective in comparison with basalt fiber against freeze-thaw action.