What Is GFRC?
Glass fiber-reinforced concrete consists of high-strength, alkali-resistant glass fiber embedded in a concrete matrix. In this form, both fibers and matrix retain their physical and chemical identities, while offering a synergistic combination of properties that cannot be achieved with either of the components acting alone. In general, fibers are the principal load-carrying members, while the surrounding matrix keeps them in the desired locations and orientation, acting as a load transfer medium between the fibers and protecting them from environmental damage. The fibers provide reinforcement for the matrix and other useful functions in fiber-reinforced composite materials. Glass fibers can be incorporated into a matrix either in continuous or discontinuous (chopped) lengths.
Durability was poor with the original type of glass fibers since the alkalinity of cement reacts with its silica. In the 1970s alkali-resistant glass fibers were commercialized. Alkali resistance is achieved by adding zirconia to the glass. The higher the zirconia content the better the resistance to alkali attack. The best fibers have zirconia contents of 19% or higher.