Reinforcing Steel Bars
D.C.Demetriades Ltd is one of the leading importers of reinforcing steel bars and electrowelded mesh in our country. We have supplied with steel some of the most important projects in Cyprus. We can deliver on time, with our fleet of trucks, equipped with special hydraulic mechanisms for unloading purposes.
Steel has an expansion coefficient nearly equal to that of modern concrete. If this weren't so, it would be useless for reinforcing concrete. Although rebar has ridges that bind it mechanically to the concrete with friction, it can still be pulled out of the concrete under high stresses, an occurrence that often precedes a larger-scale collapse of the structure. To prevent such a failure, rebar is either deeply embedded into adjacent structural members, or bent and hooked at the ends to lock it around the concrete and other rebar. This first approach increases the friction locking the bar into place while the second makes use of the high compressive strength of concrete.
Common rebar is made of unfinished steel, making it susceptible to rusting. As rust takes up greater volume than the iron or steel from which it was formed, it causes severe internal pressure on the surrounding concrete, leading to cracking, spalling, and ultimately, structural failure. This is a particular problem where the concrete is exposed to salt water, as in bridges built in areas where salt is applied to roadways in winter, or in marine applications. Epoxy-coated rebar or stainless steel rebar may be employed in these situations at greater initial expense, but significantly lower expense over the service life of the project. Fiber-reinforced polymer rebar is now also being used in high-corrosion environments.
Welding
Most grades of steel used in rebar are suitable for welding, which can be used to bind several pieces of rebar together. However, welding can reduce the fatigue life of the rebar, and as a result rebar cages are normally tied together with wire. Grade A706 is suitable for welding without damaging the properties of the steel.
Rebar sizes and grades
Grades
Historically in Europe, rebar comprised mild steel material with yield strength of approximately 250 N/mm². Modern rebar comprises high-yield steel, with a yield strength more typically 500 N/mm². Rebar can be supplied with various grades of ductility, with the more ductile steel capable of absorbing considerably greater energy when deformed - this can be of use in design against earthquakes for example
Weight of mild and deformed reinforcing steel bars per linear meter
Diameter | Kg/Lm (Linear Meter) |
6mm | 0.222 |