No, no fiber can do that. Concrete can be made "waterproof" by paying close attention to mix design, especially maintaining a water to cement ratio below 0.40. But cracks play a large part in allowing water to penetrate the concrete. Polyvinyl alcohol fiber provide excellent control of all types of cracking, including plastic shrinkage, drying shrinkage, autogenous and map cracking, differential curing cracking, settlement and structural cracking.