As the pavements are in exposure to severe meteorological conditions and experience freezing and thawing in some periods of year, which causes the most damage to the pavement in winter and spring, concrete pavements are expected to have adequate durability against inclement weather condition, in addition to strength parameters. Because of some problems of usual concrete overlays like low energy absorption, since 2004, fiber reinforced concrete overlays have been used successfully in road construction projects. In this study we aim to investigate the durability of fiber-reinforced concrete with modified polypropylene fibers against freeze and thaw cycles. To do this, the control sample was made with 400 kg/m3 cement and the w/c ratio was 0.38. Three mixtures with 3.5, 4.5 and 6 kg/m3 of fiber were also made. Then fast freeze and thaw test in water was conducted on the samples according to ASTM C666.
Three samples of each mixture were made and tested by 300 successive freeze and thaw cycles in Road, Housing and Development Research Center and parameters like percent of relative dynamic module, length variation and weight variation were measured. The results show that adding modified polypropylene fiber, decreases the durability of concrete against freeze and thaw.