Replacing Rebars with higher Grade Rebars

Project:www.sefindia.org
Component:Code
Category:support request
Priority:critical
Assigned:devendrabjoshi
Status:active
Description

Design has been carried out using Fe500 Grade Rebars.

It is found while testing Rebars received at site, that they have property of Fe600, even though it was ordered as Fe500. Rebar diameter is as per Design. In such situation it is common to accept as Rebars have better strength parameters. Chemical Composition satisfies requirement of Fe500 and fe600.

Structural Engineer has problem at hand of Approving the Rebars at site. Structural Engineer need to consider following two points:

1. It is possible that some of Flexural Members may become Over reinforced category, which were Under reinforced. In such case, Non-Ductile or Brittle Case is created. Obviously this is not acceptable for Members Resisting Seismic Forces.
2. Seismic Response of Structure will also be higher as Structure will remain Elastic up to higher stresses. This can make Design unsafe since they are based on Fe500. Foundation Design is of highest concern, for Bearing Pressure and Structural Strength.

Updates

#1 submitted by phubdorjiwang on Sat, 08/21/2010 - 05:45

I don't see any problem in using tmt bar of higher grade provided it meets minimum elongation requirement of grade Fe 500. Any additinal strength will be plus point.