Rebar, a blended, shortened term for reinforcing bar or reinforcement bar, is common steel bar, featuring ridges for frictional adhesion to concrete. Usually formed from carbon steel, rebar steel is an important component of concrete-based and masonry structures.

Though concrete is very strong in compression, it has virtually no strength in tension. To rectify this imbalance, rebar steel is embedded into the concrete to reinforce it, enabling the capability of carrying tensile loads.
 

In order for rebar steel to be impervious to rusting, numerous types have been developed for areas regularly exposed to salt water, asn marine applications, or bridges built in areas where salt is applied to roadways to melt the ice in the winter. Rust takes up greater volume than rebar steel, causing severe internal pressure on the surrounding concrete, leading to cracking, splintering, and over time, possible threat of structural failure. The range of rebar steel available to the construction industry for use in high-corrosion areas and applications includes: Fusion bonded epoxy-coated Stainless steel Fiber-reinforced polymer There are other materials aside from rebar steel, which could provide sufficient tensile strength to reinforce concrete, but steel and concrete have a special relationship in that they contract and expand very similarly to temperature variations, minimizing the stress

the concrete structure has to endure. If the expansion properties of reinforcement bars fashioned from an exotic material other than rebar steel were to react significantly from environmental influence, the potential consequences to the masonry structure they were supporting could be catastrophic.