Three kinds of fibers with different rate of moisture regain were selected to study the effect of hydrophilism of fibers on the durability of fiber reinforced concrete during freeze-thaw with the rapid freeze-thaw cycle experiment.Microstructure of fiber-cement matrix were observed using SEM before and after freeze-thaw.The results showed that compared with the hydrophobic fibers,since the latter can be tightly bonded with cement matrix together hydrophilic fibers can effectively inhibit the initial micro-defects of concrete and prevent the growth of micro-defects in the freeze-thaw cycles.Therefore,hydrophobic fiber concrete may even accelerate the growth of damage during freeze-thaw cycles,due to the interfacial performance between fibers and concrete is weak.With the increase of freeze-thaw cycles,the impact on frost resistance of concrete by the hydrophilic of fibers became more and more obvious.
