Experimental Study of Mechanical Properties of PVA-ECC under Freeze-Thaw Cycles

Abstract In order to study the mechanical properties of engineered cementitious composites reinforced with various types of polyvinyl alcohol fibers and different fiber volume fractions subjected to freeze-thaw cycles, the rapid freeze-thaw method was used to test the mass loss ratios, relative longitudinal dynamic elastic modulus, compressive strength, and flexural strength. Two different fiber types (JP and CP) and two different fiber volume contents (1.0 and 2.0 %) were used in the test specimens. The results showed that specimens incurred more damage with the increase of freeze-thaw cycles; however, their performance was improved by fiber type and dosage. The mass loss rate of specimens with 2 % volume content of fiber was lower than that of specimens with 1 % volume content of fiber. Furthermore, the mass loss rate was also influenced by the type of fiber used. The relative longitudinal dynamic elastic modulus of specimens with 2 % fibers was higher than that of specimens with 1 % fibers, while the relative longitudinal dynamic elastic modulus of JP fibers was higher than that of CP fibers. In addition, the compressive and flexural strengths decreased with the increase of freeze-thaw cycles, but specimens with fiber exhibited better compressive and flexural strengths than specimens without fibers. Based on the SL 211-2006 code for the design of hydraulic structures against ice and freezing action, specimens with JP fibers were adequate for use in severely cold regions, while specimens with CP fiber can be used in cold regions, and specimens without fiber could only be used in warm regions.