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Deflection of RCC Beam Due To Early Striking Of Form-Work

08/28/2011 6:04 AM

Dear all,

The RCC beam member of span about 10m and size of 0.6m x 1.4m deep beam form-work dismantling was done after the period of 6 days of concrete (M30 ) pouring.

If there is any possibilities of deflection of beam due to early striking of form work?

Definitely there will be a deflection, then how we will check the deflection, stability and stiffness of the beam?

Thanks in advance for your valuable reply.

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N.Vigneshkumar
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#1

Re: Deflection of RCC beam due to early striking of form-work

08/28/2011 6:35 AM

Hire a competent civil engineer to check your test pours that should have been made with each batch of concrete.

It's a little late to be concerned, now that the beam has been poured.

What else did you not consider prior to beginning the pour?

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#3
In reply to #1

Re: Deflection of RCC beam due to early striking of form-work

08/28/2011 7:10 AM

Dear Sir,

Now the point is not about the quality of concrete and the method of casting.

The concrete pouring done before 6 days after all the checking.

Due to the earlier dismantling of form work, the micro cracks may developed. Its not possible to view these cracks in normal vision.

So what are the methods are available to check the deflection and stiffness for beam?

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#2

Re: Deflection of RCC beam due to early striking of form-work

08/28/2011 6:37 AM

I'm not sure I understand. I think you are asking if there would be damage caused by the early form removal. Look for cracks in the concrete. Better still, hire an experienced structural engineer.

"Definitely there will be a deflection, then how we will check the deflection, stability and stiffness of the beam?"

Do you normally check these things after construction? What are your usual points of reference?

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#4
In reply to #2

Re: Deflection of RCC beam due to early striking of form-work

08/28/2011 7:31 AM

Dear Sir,

We are checking the general things like sagging ,honey combs and surface cracks if anythings by observation.. But we follow the IS codal provision for stripping time of form work.

In these case the early dismantling of form-work happened by mistake of supervision.

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#5

Re: Deflection of RCC Beam Due To Early Striking Of Form-Work

08/28/2011 6:19 PM

Load it with test weights and measure if it deflects excessively?

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#8
In reply to #5

Re: Deflection of RCC Beam Due To Early Striking Of Form-Work

08/29/2011 7:37 AM

Any NDT ( Non destructive Test) method is available to test the stiffness and stability of beam?

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#6

Re: Deflection of RCC Beam Due To Early Striking Of Form-Work

08/29/2011 2:55 AM

Hi Jai,

I suppose you must have hired Civil/Structral Engineer. What he has to say?. What are his observations?. Is beam properly designed?. During casting was it properly supported?.

Was the cement of good quality?.

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#9
In reply to #6

Re: Deflection of RCC Beam Due To Early Striking Of Form-Work

08/29/2011 9:10 AM

Everything is fine except the earlier de shuttering if form work.

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#11
In reply to #9

Re: Deflection of RCC Beam Due To Early Striking Of Form-Work

08/30/2011 6:44 AM

Then your Civil Engineer is right person to suggest the solution. I can only say that you should recast the Beam or provide new column in the center of the beam.

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#7

Re: Deflection of RCC Beam Due To Early Striking Of Form-Work

08/29/2011 5:32 AM

The formwork was removed prematurely? If so, are you asking if someone here will recommend a method for justifying to the authorities in charge of building code enforcement for granting an exception? Seems likely that your only course of action is to get engineer, contractor, owner and building official in same room, and lay it out.

To answer your question, yes, there is a very good possibility of beam deflection, and reduced strength, due to early form striking.

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#10

Re: Deflection of RCC Beam Due To Early Striking Of Form-Work

08/29/2011 9:10 AM

If you are wanting the form to support the beam while pouring concrete, wrong way to design a pour to start. Forms are to "form" a mold of sorts and hold liquid materials to shape only. Support of structures are the form the footers and such take after cure. Not sure what you are doing here, but like others you need to contact professional engineer to come on site.

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