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Padmanabhan G SEFI Member
Joined: 27 Jul 2010 Posts: 10
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Posted: Wed Sep 01, 2010 5:18 am Post subject: Use of 500 grade Re bars |
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Dear Sirs,
I have a problem.. I have designed a two sotried building with FE 415 bars and constructed the ground floor using FE415. Now if I want to construct the upper story with FE 500 grade steel, is it is advisable to use FE 500 for upper storey. What precautions I have to take for use of FE 500 grade steel for upper storey construction. Please suggests your views on this.
Thanking you
Padmanabhan.G |
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sharad SEFI Member
Joined: 30 Jul 2010 Posts: 4
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Posted: Wed Sep 01, 2010 10:48 am Post subject: Re: Use of 500 grade Re bars |
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Dear Padmanabhan,
You can very well proceed with your plan of using Fe500 for the upper floors.
But, don't forget to redesign the rest of the structure for Fe500 steel to extract maximum benefits (obvious!!).
Also, pay special attention in detailing the 'transition zones' in columns from the roof of GF onwards, in terms of lapping and stirrups.
Best of Luck!
-Sharad
Padmanabhan G wrote: | Dear Sirs,
I have a problem.. I have designed a two sotried building with FE 415 bars and constructed the ground floor using FE415. Now if I want to construct the upper story with FE 500 grade steel, is it is advisable to use FE 500 for upper storey. What precautions I have to take for use of FE 500 grade steel for upper storey construction. Please suggests your views on this.
Thanking you
Padmanabhan.G |
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umeshrao ...
Joined: 23 Aug 2010 Posts: 573 Location: Bangalore, India
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Posted: Wed Sep 01, 2010 2:30 pm Post subject: Re: Use of 500 grade Re bars |
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Padmanabhan G wrote: | Dear Sirs,
I have a problem.. I have designed a two sotried building with FE 415 bars and constructed the ground floor using FE415. Now if I want to construct the upper story with FE 500 grade steel, is it is advisable to use FE 500 for upper storey. What precautions I have to take for use of FE 500 grade steel for upper storey construction. Please suggests your views on this.
Thanking you
Padmanabhan.G |
Dear Mr. Padmanabhan,
Mixing of two different grade of steel in the same element is wrong. Since elongations are different. Fe415 has @15% elongation and Fe500 has @12% elongation.In fact it as quite a common practice in late 60's [when Fe 415 was introduced and prevalent grade of steel was Fe250] to provide stirrups in mild steel and longitudinal bars in 'CTD'. It means that tension steel provided ,let's say, at bottom of beam can not be a mix of different grade of steel, however in the same beam top steel provided at the support can be of different grade of steel than that was provided for bottom. This is true for singly reinforced sections.
Extending this concept you may choose to in the two way slab to provide two directions steel of different grades if you wish and desire.Like in the one way spanning slab main reinforcement may be Fe500 and distribution may be Fe415 or Fe250.
There is no bar and I am of the opinion there cannot be,since we design at that section of the element.
You may not be able to use it two different grade of steel when design a beam for moment along with torsion, since you convert torsion to equivalent moment.You may choose the same grade in the element.
Regards Umesh Rao |
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Padmanabhan G SEFI Member
Joined: 27 Jul 2010 Posts: 10
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Posted: Mon Sep 06, 2010 11:07 am Post subject: Use of 500 grade Re bars |
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Dear Sir,
My question of using FE 500 was for the entire second storey of the building and not for some of the structural members. However you have highlighted the problem of using FE 500 in combinaiton with FE 415 in different structural members.
Regards
Padmanabhan.G |
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badamsundararao ...
Joined: 24 Dec 2009 Posts: 218 Location: KAKINADA ANDHRA PRADESH
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Posted: Wed Sep 08, 2010 5:01 pm Post subject: Fe 500 grade steel |
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Dear friend,
My suggestion to your problem is, as there is common point for ground floor and upper floors is only Columns, you design columns for this particular floor ,as if you are using Fe 415 grade steel and you can safely design all other members as with Fe 500 grade steel. This can be a safe of doing.
badam sundara rao. |
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bkkk ...
Joined: 25 Mar 2009 Posts: 203 Location: Tamil Nadu
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Posted: Tue Sep 21, 2010 11:19 am Post subject: Use of Fe 500 Steel |
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Sir,
you have not mentioned whether your structure needs ductile detailing or not. IS has recommended the use of FE415 in place of FE 500 on account of Ductility.Please check this
Er.Balaji Venkateswaran |
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jagadeshkannan General Sponsor
Joined: 01 Aug 2008 Posts: 71 Location: coimbatore
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Aneesh_Surjith SEFI Member
Joined: 05 Jul 2018 Posts: 12
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Posted: Fri Jul 20, 2018 9:42 am Post subject: Why do you feel you need Fe500 |
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You obviously designed a two story building and started construction, now why would you need to change from one grade of TMT to another. I am not criticizing your action, rather curious on why you would switch halfway through eventhough Fe415 is the most recommended for homes and similar structures. |
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