Expansion Joint Variance

[Thane]

Where can I find some general guidelines or a table that gives the different sizes of an expansion joint at different ambient temperatures in an open air concrete structure? I suspect that it will vary with slab thickness, size of structure between joints, type of concrete construction, etc. However, I am just looking for something I can use as a rule of thumb.

For example, the building plans specify a nominal 3" wide expansion joint in a concrete structure such as a parking garage. What size should the joint be at 40 degrees F? What size should it be at 95 degrees F?

Thank you in advance for your help.

 

[JAE]

thane,
It is simply a function of temperature differential and distance between joints - Look up the coefficient of thermal expansion for concrete - take the anticipated temperature differential and calculate the amount of movement.

Its something like 0.000656 x distance x temp diff
(the .000656 number may be wrong - please look it up - I'm away from my office right now).

Now consider that this is the amount that concrete will SHRINK. It may be moving inward/outward across a series of columns or other supports and these may inflict different stiffnesses and the net result of movement at each end may be different.

 

[ajose]

Thane,

I'm agree with JAE, but also have to be taken the structural analysis and the seismic forces. The seismic event has no fixed time and could happen at midday on summer.

The design have to be found adding the max displacements.

Your problem could be solved by products for bridges. This for the loads the structure is handling.

One place could be:

http://www.dsbrown.com/

Allways has the backup of searching on the net with the criteria.

Ajose

 

[JAE]

Yes, ajose has a good point - seismic and wind (most usually seismic) is also a factor in the joint width.