Concete Expansion Joints

[Fatalxception]

I always think about control and construction joints in concrete slabs and walls but not expansion joints. When are you supposed to put in expansion joints?

 

[Ginger]

Whenever the size of the structure is such that expansion stresses (say due to heat gain in the sun) cannot be carried by the structural elements. For example, in highway construction, the heated road surface would buckle if the facility for movement in the form of expansion joints was not there. generally in structures greater than 40m long a movement or expansion joint is often specified.

 

[JAE]

We've usually stretched out the length between building expansion joints to 300 to 400 feet (90m to 120m). If you have a copy of the AISC Steel manual, they have a chart that indicates rough expansion joint recommendations for buildings - It is in Part 1 of the manual on page 1-13 (LRFD Second Edition).

 

[qmorr]

What are the materials they inject in to the sawcut expansion
joints they cut into concrete roads ?

 

[Lutfi]

They inject sealers in the saw cut joints. I require them on all of my plans, when saw cut joints are required. I recommend using material that is non-sulfide based.

Joints should be prepared properly and as follows: Thoroughly clean dry joints using compressed air. This will remove dirt, dust, and other foreign matter. The air compressor shall have:

1. Minimum rated capacity of 100 psi
2. Sufficient hose for continuous cleaning operations

Here is a quick link to joint sealing:

http://training.ce.washington.edu/WSDOT/Modules/07_construction/07-10_body.htm#joint_sealing

Regards,



Lutfi

http://www.cdeco.com