Steel Reinforcement Test To BS4449 2

[albert1]

Hi

Normally in the steel reinforcement test, we check for yield stress, ultimate tensile stress and elongation. i have come across a case where the rebar had achieved the yield stress and ultimate tensile stress but with very low elongation ? what is the reason ? another question is what is the relationship between yield stress and ultimate tensile stress ?

Thanks

 

[johncuthbert]

Where yield and ultimate stress occur with low elongation, the material tested must be of, higher than normal, brittleness the only problem you will encounter is when the material fails it will be more sudden. The only relationship is in the ductility/brittlness of the material.

 

[gthelen]

albert1,

You must also check the location of the break after the tensile test. If it breaks near the grip, it will more than lokely fail the elongation. If it breaks in the middle area of the sample look for discontinuities in the steel, a lamintation, roll mark and other items, any discontinuity will cause low elongation but good yield and tensile.

Most rebar has some bad surface and are hard to test, base the elongation on several samples not just the one.

gthelen

 

[Justman]

There is another fact that is stated in BS standard the ratio (ie ys/ts) & the bend test for the bar
I cannot remember the figure but you can check with the standard