Question about expansion joints in slabs or large foundations

[MrFurleyEIT]

I have got a question about expansion joints in large slabs or foundations. Are expansion joints specified for such foundations? What is the maximum distance to place an expansion joint? If possible, please provide a reference. I am working on a large reinforced mat foundation, about 500 feet long by 300 feet wide. It is about 22 inches thick. Thank you.

 

[Lion06]

I am very curious to hear other's opinions on this, but I would think you should be more concerned about control joints than expansion joints.

 

[civilperson]

What temperature change do you imagine will impact this mat foundation? If the delta temperature is less than fifty degrees, and no restraint is built in by connecting to adjacent structures then no expansion joint should be necessary. However, I would design construction joints at quarter points and place alternate strips in differing placements to minimize shrinkage. Use vertical construction joints fashioned out of steel mesh with the reinforcement continuous through the joint.