Expansion joints

[Refaatfaraj]

Hello all

Could someone provide me any technical reference which showing the maximum length of concrete structure that can considered without expansion joints?

Thanks inadvance.

Refaat

 

[hokie66]

Have you done a search of the site? There have been many threads about expansion joints.

 

[Refaatfaraj]

Hi @ hokie66

Yes, of course. But I am looking for a technical reference. As far as remember there is a reference from (PCA) (Portland cement association) for instance.
or you may have another references .

Recently, I am experiencing this issue with my project. I want to take decision regarding to the possibility of considering the expansion joint or not . The structure is about 62 m length and the width is about 45 m .

Any help will be appreciated

Refaat

 

[klaus.]

I am not a concrete designer but I would say....it depends on the structure
I am sure you can do 100 m or more without expansion joints... if the structure can take the movements


best regards
Klaus

 

[patswfc]

Refaatfaraj,

Rule of thumb that i know is to try and provide joints at 50m crs in concrete structures (UK practice)

Ciria Report 91 (old document on early thermal cracking of concrete, now replaced by Ciria C660) suggests expansion joints at up to 70m crs.

It will depend on the shape of the structure and the local climate. The lower the temperature range that the structure is exposed to, the lower the amount of expansion. Also if your dealing with a concrete framed building with air con, etc. then the temperature range in the concrete frame will be lower than climatic temperature range. If however you have an exposed structure, e.g. an exposed tank, than this will be subject to a higher temperature range.

For the dims of your structure it should be possible to design without an expansion joint (dont know the geometry, climate, etc.). If your have software capable of applying temperature loads to the structure you should be able to quickly see if there are any areas that are developing excessive stresses and if so then an expansion joint may be required.

 

[wannabeSE]

In the US,most articles on expansion joints cites Technical Report 65,

https://www.nap.edu/catalog/9801/expansion-joints-in-buildings-technical-report-no-65

 

[JAE]

AISC has this section which includes concrete buildings:

Check out Eng-Tips Forum's Policies here:
faq731-376

 

[Refaatfaraj]

Hi all

Thank you so much. I really appreciate your help

Since the structure behavior will be horizontal movement due to the temperature.

Shall I apply in the structural model the temperature loads on the horizontal structure elements (slabs & beams) only or should be applied even on the structure vertical elements (walls & columns)?

Refaat

 

[SlideRuleEra]

Shall I apply in the structural model the temperature loads on the horizontal structure elements (slabs & beams) only or should be applied even on the structure vertical elements (walls & columns)?

Thermal expansion works exactly like enlarging a photograph. If the temperature of the entire structure goes up, the structure get longer, wider, and higher (that is, it expands in all three dimensions).

Many get confused by the following situation:
If the structure has an opening, say for a window, with temperature rise what happens to the size of the opening?
It gets bigger... just like it would in a photo enlargement. Often, people "overthink" this and assume the opening will get smaller as the structure gets larger.

http://www.SlideRuleEra.net

http://www.VacuumTubeEra.net

 

[Refaatfaraj]

Hi SlideRuleEra

Thank you for your clarifications .

If I understand you correctly you meant to apply the temperature loads on all structural elements ( both horizontal & vertical ) .

Refaat

 

[klaus.]

well it depends on the situation
Your Model has to reflect the real situation as good as possible also the loads
this is always the responsibility of the engineer doing the work



best regards
Klaus

 

[dik]

If the building plan had changes in geometry, then your expansion joints should accommodate these changes.

Dik

 

[SlideRuleEra]

Refaat - I agree with Klaus. For thermal expansion, the model should consider temperature variations over the entire structure. In many cases, just looking at the horizontal conditions and neglecting vertical expansion is reasonable. My comment is to point out that assuming vertical expansion is never a consideration is just not accurate.

http://www.SlideRuleEra.net

http://www.VacuumTubeEra.net

 

[dik]

If the structure is temperature controlled, then the delta should be for the operating environment... with consideration for when the structure was erected.

Dik

 

[Refaatfaraj]

Hi all

Many thanks for your concern,

I am thinking to see if the total structure displacement in both cases ( entire structure , horizontal only ) are very closed that means the applying thermal loads over the horizontal structure elements will be enough for structural analysis .


Great forum. Best resource by far!

Refaat

 

[dik]

Does this help?

Dik

 

[Refaatfaraj]

Dear Dik

Yes , of course . Thank you so much

Appreciated help
Refaat