When a lot of steel received at site, First check the Manufacturer test certificate for its actual properties.
With each lot of steel, the manufacturer should send a test certificate of the same lot for the test done at their laboratory. Check for grade of steel mentioned in the certificate and is as per the order or not.
Steel bars may have rusting on them, do check closely to know either it is acceptable or not.
Steel received should be free from any contamination like, mud, dust, oil and any other foreign material etc.
Bars should not have splits and any other deformation on it.
Causes of Rusting:
Primary steel which is made from pure iron ore are likely to get rusted quicker compared to secondary steel.
Bars may get rusted due to contact with water or air and atmospheric condition.
Brownish bars showing little rusting due to weathering are good for use. A small amount of rust is good for bonding of steel and concrete. If excessive scaling observed on the surface of bar, it should not be accepted.
At site you can bend it on bar bending machine using appropriate size mandrel. After bending the bar check the surface of the bar opposite to the bend side (which got tension, elongated due to bending) for cracks and rupture visible to a person with normal or corrected vision.
If there is no sign of rupture and cracks, rebar meets the requirement of the bend test.
Further to this a rebend test also can be done at the site, if required.
For Rebend Test
First bend the bar to including angle of 135 degree.
Keep it in boiling water at 100 degree for 30 minutes.
Then cool it down for some time.
After cooling bent it back to including angle of 157.5 degree
The rebar should not show any rupture or cracks