PVA is a water-soluble synthetic polymer. PVA can be made into fibers, with a typical diameter of 10-50 micron and a typical length of 6-12 mm. The tensile strength is about 1200-1600 MPa. PVA fibers are often used to reinforce concrete to reduce cracking induced by shrinkage and improve tensile and flexural properties.
PVA can also be used in concrete directly. The addition of PVA can increase the cohesion and fluidity. However, since PVA can react with alkali in concrete, the cohesion decreases gradually.