Compatibility of Concrete and Steel
The combination of steel and concrete can produce high strength and durable structures. concrete and steel work in harmony to resist loads imposed in structures. concrete and steel compensate for the weakness of each other. this can be found in the following:
- concrete tensile strength is very less. on the other hand, steel possesses high tensile strength. steel will compensate for the weakness of concrete by resisting tensile stresses.
- The bonding between steel and concrete is very good. steel rough surface and closely spaced ribs on the bar surface. this will result in a strong bond between reinforcing bars and concrete and the possibility of slippage will be minimal. as a result of the strong bond between concrete and reinforcing bars. reinforcing members will work together as a single unit. steel bars must be embedded in concrete sufficiently to produce a bonding more than yielding of steel.
- Exposed steel will get rusted quickly. the rust will reduce the steel cross-section and it will reduce the tensile strength of steel. here comes the concrete role. concrete will confine steel and protect it from the weather.
- heating of steel will reduce its strength. concrete will produce good protection against fire. enclosing steel bars in concrete produce sufficient protection against fire.
- the coefficient of thermal expansion of steel and concrete are very close. therefore the change in size resulted from temperature change will be similar. the coefficient of thermal expansion of steel is 0.0000114. the coefficient of thermal expansion of concrete is 0.000010 (°C)