Dear Kolawole Afolabi ... Thanks for answering...

If the reinforcement did not have any defect (cracks).

I think it is possible, but under load level less than the loads and conditions of the buildings in which the steel bars were extracted from.

If the reinforcement didn't have any defect or problems like rust.

Never re-use these rebars for other construction because you know nether the steel grade (mechanical properties) nor the behavior of these reinforcement (fatigue, plastic deformation, ...) during their life and more particularly during the demolition.

The collected rebars must be scrapped to be re-used only by smelting (steel melting shop) to get new steel.

Colleague Jean-Françoise Noville is very correct.

Never reuse rebar for actual structural construction. You might consider using it in a non-structural application such as curb or sidewalk on grade.

Never reuse it. it has gone through large deformations.

Yes we can, l used for many new buildings in Iraq, at the embargo time I.e. before 20th year ago...

You can take sample and check fy and elongation for this reinforcement.

Thanks

Dear Mohannad H. Al-Sherrawi .. thanks for answering..

But did the defect (crack) will be checked by eyes and evaluated by site engineer or what..?

Dear Qasim M. Shakir .. thanks for answering..

So you think that the extracted steel is not that much effective and have not the same strength as it used for the first time.. so you prefer to use under low loading..

Ola Adel Qasim ... thanks for answering...

How can we evaluate that... is it just by direct check .. looking for any defect or rust.. or we need to do some laboratory tested..?

Dear Jean-François Noville ..thanks for answering..

Agree with the item, ... that mechanical properties will change, and an addition, to that, the changed can't be predicted or its almost has unknown behavior ... but.. there are many parts in the structure may need the minimum requirement of reinforcement...so can we increase this ratio by re-using that reinforcement..?

Dear Chettri Nmesh

Dear Soheyl Sazedj ... thanks for answering..

Dear Craig Rethwilm ... thanks for answering..

Dear Salim Kouloughli ... Thanks for answering

Steel reinforcement is infinitely recyclable, More than 65% of all reinforcing bars are recycled, according to The Steel Recycling Institute. However, you can see

https://jeaconf.org/UploadedFiles/Document/e5178948-e9d9-4257-80e2-433e8516498d.pdf

From the research above they can used but after making some mandatory test.

Dear Ayad A. Abdul-Razzak ... Thanks for answering..

So you think that the reinforcement extracted from old building is the same quality and strength as the new one..? You know that structural design based on the strength of steel reinforcement...

Dear Aymen J Alsaad .. thanks for answering.. and for the reference..

Re-used Steel

A concrete reinforcement steel whether mild or high yield should meet specified minimum values given in standards for it to be suitable for reinforcement and these are:

1. Minimum yield stress, fy

2. Maximum tensile strength , ft

3. Minimum elongation at failure, dl

4. Minimum ratio: ft/fy

For cold worked steels a proof stress is specified, usually the stress at 0.02% elongation.

Steel obtained from a demolished building cannot meet the above criteria because of excessive bending of the steel during demolition which may make the steel yield. More over the steel is unlikely to be of uniform quality due to things like corrosion etc.

I think we can use the reinforcement taken from demolition because the old buildings designed using the elastic theory i.e. the reinforcement doesn't reach fy.

So we can check the standard for this reinforcement ( mentioned by Dr Alex ) and decided if we use it or not depends on the results of the Laboratory...

Note: The reinforcement used must be clean.

Thanks

Dear Alex Mrema .. thanks for answering.. really useful information..

Dear Ayad A. Abdul-Razzak .. thanks for answering... thanks for sharing your opinion.. I really appreciate..

شكرا جزيلا دكتور حسام علي

اتمنى لكم الموفقية والنجاح الدائم

تقبلوا بالغ تقديري واحترامي

Right from my view,it is wrong,u can only take it to recycling industry to be recycled

Dear Kolawole Afolabi ... Thanks for answering...

Kindly, you may refer to my article, since we examine the reused steel bars.

Article Applying Reused Steel Bars to New Constructions (A Case Stud...

Good question

Following

NO. We can't.

never ever think of reusing reinforcement

extracted from demolition of a building for the construction of a new building. send such reinforcement for re rolling. after re rolling only you can think to use.