Composites are engineered materials consisting of two or more constituent materials that work together to provide enhanced mechanical and chemical properties. Fibre-reinforced polymers (FRP) typically comprise reinforcing fibres embedded in a polymer matrix. Common reinforcements include glass fibre, carbon fibre or combinations of both.

Building elements, particularly bridges, often have to be restored or even replaced due to corrosion damage to steel reinforcement, which leads to the destruction of the concrete structure. This is especially true for components that are exposed to de-icing salts. With the expansion of GRP reinforcements, (Glass fiber Reinforced Polymers), which are more economical than Carbon fiber, GRP reinforcement eliminates the risk of reinforcement corrosion associated with conventional steel reinforcement. It drastically reduces the number of repairs needed. GRP reinforcements are mainly applied to concrete and polymer concrete building parts

In recent decades, steel reinforcement has been replaced with other materials in connection with the renovation of old concrete structures, which has led to a sharp increase in the use of fiberglass and carbon fiber reinforcements, among other things.

The simplest composite is the laminate. A laminate consists of fibers impregnated with a matrix. The properties of laminate are determined, among other things, by the properties of the constituent materials. The fibers make up the reinforcement, and the matrix is the binder that holds the reinforcement in place.

The binders used are so-called thermosetting resins that contain sufficient catalysts, UV stabilizers and pigments. Through this mixture, a connection is made to ensure the mechanical and chemical properties required.

polyester, vinyl ester and epoxy resins are among the most common resins in composite materials and are resistant to oil, acids, brines, gasoline, alcohols, organic solvents, in general with a wide service temperature range.  With Vinyl Ester as a matrix for GRP Profiles, an even higher chemical resistance is achieved.