Shrinkage in concrete
Shrinkage in concrete
(OP)
I have a concrete slab, which are restrained in both ends.
When designing for cracks in SLS, do I have to consider stresses from shrinkage and stresses from static load separately. Or shall I add the stresses together?
When designing for cracks in SLS, do I have to consider stresses from shrinkage and stresses from static load separately. Or shall I add the stresses together?






RE: Shrinkage in concrete
RE: Shrinkage in concrete
RE: Shrinkage in concrete
RE: Shrinkage in concrete
RE: Shrinkage in concrete
RE: Shrinkage in concrete
RE: Shrinkage in concrete
Do not calculate them separately and add.
You may also need to allow for restraint to temperature change depending on the situation.
RE: Shrinkage in concrete
RE: Shrinkage in concrete
Do you use a temperature differential load for modelling shrinkage effects?
RE: Shrinkage in concrete
So for example if a house has a 4" slab the typical sawcut control joint spacing is 12 feet on center. I'll start the first control joints 6feet from each edge of the building just to be safe. And I'll do the same thing to relieve any internal turned down slabs....
I learned this the hard way building my own house. And honestly any more I don't hesitate to space joints on a 4" slab at 10 feet on center. Adding joints in the right locations makes a huge difference in the performance of you slab. Heck look at your average cracked driveway and they simply spaced the joints too far apart. It is amazing to me that this happens all the time and this is something that anyone can understand using a simple rule of thumb.
Sorry I know this is a bit off topic versus a structural slab. But restraint from turned down slabs is something I'm more aware of now and I thought everyone else should consider it also when locating control joins on their plans. Even a simple driveway if you turn down the edges of each side of the driveway can make things worse. Food for thought.
John Southard, M.S., P.E.
https://www.pdhlibrary.com/