Because non-metallic fibers may resist chemical attack, they could potentially replace steel as a reinforcing material. Fiber/epoxy composites also demonstrate some advantages over steel in prestressing applications. Most notably, prestressing losses with fiberglass or graphite fibers are less than for steel. More general use of prestressing (with any material) could help eliminate cracking in concrete bridge decks.
Lack of critical knowledge prevents widespread application of composite technology in structures. Not enough is known about the materials behavior under load. Unlike steel, which can withstand large plastic deformation when overstressed, fibers break suddenly; larger safety factors may therefore be required to ensure structural integrity. Design guidelines are not yet available, and recommended construction practices have not been determined. Without this information, engineers are unable to use composite technology for highway structures.