RC Beam deflection - a few questions

RC Beam deflection - a few questions

Anonymous
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RC Beam deflection - a few questions

Anonymous
Not applicable

I have a few questions concerning the deflection calculation of RC BEAMS to Eurocode 2.

1. Is it possible to set the exact time in which a dead load is added to the deflection calculation? For example I want to add the dead-load of floor layers after 84 days, after 120 days the dead-load of partition walls.

2. Is there a way to control the value of the RH parameter over time? I want to divide the calculation process into two stages:
a. construction stage up to 365 days in which RH=80%
b. from 365 days up to 50 years in which RH=50%.

Setting the correct value of the relative humidity and its change over time is necessary to properly calculate the value of the creep coefficient and as a consequence the deflections. I need two values of the creep coefficient, for each stage a different value.

 

I only found one window in which I can set a value for RH:

 

story.png

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

I understand that the value that I insert in the window above means that the program assumes a humidity of 60% in the construction stage, as well as after its completion up to 50 years?

 



3. One thing I want to confirm:


Often we have to limit the allowable deflections due to the installation of a glass facade. We need to know the deflections that occurs after its installation - including its self-weight and the quasi-permanent live loads.
 If I set it as a non-structural dead load case, then I understand the deflection in which I'm interested in will be displayed as the dwt(qp) deflection?

 

deflect.PNG

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Artur.Kosakowski
Autodesk Support
Autodesk Support
Accepted solution

Hi @Anonymous



1. Is it possible to set the exact time in which a dead load is added to the deflection calculation? For example I want to add the dead-load of floor layers after 84 days, after 120 days the dead-load of partition walls.

 

In the RC Beam design module there are 3 defined points in time:

 

concrete age3.png

 

- Concrete age - time for which calculations are performed

- Concrete age (first loading moment) - the moment when self weight and dead loads are applied 

- Concrete age after erecting a structure - time when QPR combination is applied

 

therefore it is not possible to define the moments to apply loads in the way you asked for.



2. Is there a way to control the value of the RH parameter over time? I want to divide the calculation process into two stages:
a. construction stage up to 365 days in which RH=80%
b. from 365 days up to 50 years in which RH=50%.

 

There is no such possibility.

 

3. One thing I want to confirm:


Often we have to limit the allowable deflections due to the installation of a glass facade. We need to know the deflections that occurs after its installation - including its self-weight and the quasi-permanent live loads.
 If I set it as a non-structural dead load case, then I understand the deflection in which I'm interested in will be displayed as the dwt(qp) deflection?

 

 

Correct.

 

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.



Artur Kosakowski
Message 3 of 4

Anonymous
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Thank You Mr. Artur Smiley Happy

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Message 4 of 4

hhyppolito
Participant
Participant

Hello guys,

 

I'm trying to find this tab to set the long term properties for a concrete structure. Can you help me?

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