Why are joints required in concrete?
Concrete cracks. That is the nature of the beast. Shrinkage that occurs during the drying stage causes stresses and cracking in the concrete. Joints are placed in the concrete to control the location of the cracks and prevent unsightly random cracking. Typically, joints are placed in concrete every 2.5 to 3 times in feet the depth of the concrete in inches. For instance, a four inch slab should have joints every 10 to 12 feet. Joint depth should be at least a quarter the depth of the slab. A 4″ slab will require 1″ deep joints to be effective.
Related Questions
- The pay item is 10" concrete, but the specs call for 4" inlay and appears to design the joints around a 4" thick slab. Also, will the 10" pavement require dowel bars and tie bars?
- Can a concrete structure be completely free of expansion joints and contraction joints?
- Are control joints necessary with pervious concrete?
