Concrete Paving
Concrete Paving
(OP)
Have a generic question on the basic design of concrete pavement. I have seen large concrete slabs designed with just call outs for the boundary of the slab, and then I have seen slabs designed showing 20'x20' construction joints. I dont think they would ever pour a 200'x200' slab and every applicaton would have construction joints. Anyone have any imput into what the proper way to show this would be or the application of construcion joints in concrete pavement construction.
The application I am talking about in this case is an industrial yard.
Thanks
The application I am talking about in this case is an industrial yard.
Thanks





RE: Concrete Paving
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"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill
RE: Concrete Paving
RE: Concrete Paving
RE: Concrete Paving
We typically specify two types of joints, one is a sawed joint and the other an expansion joint. The sawed joints are both longitudinal and transverse directions on the slab, and we generally require a spacing no greater than 15-feet. A saw joint is is 1/8 to 1/4 inch thick, to a depth of D/4 of slab thickness.
An expansion joint is where two separate slabs of concrete meet, and are separated by a 1-inch redwood expansion board, with the top 1/2 inch filled with a joint sealant. We prefer a cold application silicon over a hot poured seal. The two slabs are connected by a smooth #6 dowel at 12" on center. They have a 6-8inch overlap with the slab reinforcement. The maximum spacing between expansion we use is 45-feet.
Nothing wrong with requiring the contractor to submit a joint spacing plan for your review either.
RE: Concrete Paving
Dik
RE: Concrete Paving
RE: Concrete Paving
Your use of wood strips brings back some history... one of my first SOG's I used plywood joints... and reasoned that the concrete would shrink away and you would be able to easily pull the plywood strips out after all the shrinkage had taken place... if the buildings are in existance still... the plywood strips are likely still there!
Dik
RE: Concrete Paving
RE: Concrete Paving
Dik
RE: Concrete Paving
RE: Concrete Paving
Richard A. Cornelius, P.E.
WWW.amlinereast.com
RE: Concrete Paving
types of joints
http://www.pavementinteractive.org/article/joints/
RE: Concrete Paving
RE: Concrete Paving
RE: Concrete Paving
Only the same when the construction sequence produces (by accident or possibly purposeful) the same spacing. Don't count on it and the terminology MUST be clarified.
"What is the downside of going bigger, say 25' between construction joints?" Depends upon the reinforcement. Usually UGLY cracking.
RE: Concrete Paving
ACI 330r recommends contraction joint spacing at 25 to 30 times the pavement thickness, up to a maximum of 15 feet. In my office we usually provide a paving plan for parking lots that includes contraction and expansion joints with dimensions. Expansion joints are placed at a maximum spacing of 60 feet, with contraction joints evenly spaced between them. We don't usually show construction joints, since starting and stopping of the concrete pour is usually governed by field conditions or schedule.
RE: Concrete Paving
RE: Concrete Paving
RE: Concrete Paving