|
concrete slab-on-grade control joint reinforcement
i have always detailed my control joints for a slab-on-grade with the reinforcement running continuous through the joint. i show a (1/4)*slab thickness cut and the steel mesh or other reinforcement running continuous. does anyone terminate there reinforcement at the joint? why?
check out our whitepaper library.
i don't detail it. i just put a note on the plan. i would put it continuous, if it is not, i wouldn't worry about it. it is only slab on grade after all.
for run of the mill thin slabs, i have usually specified that alternate wires are cut at sawn joints. just go through with bolt cutters and nip out a 4' section of every other wire. and if they saw the joint at the same place, i think it goes some way toward making the crack occur where it is intended.
i detail saw joints to have 1/3 of the reinforcing (rebar not wire mesh) continuous thru the joint. the other bars stop 3" each side of the joint. the purpose of the joint is to create a weakened vertical plane in the slab to cause the slab to crack at that location. if the bars are continuous thru the joint, there is no weakened plane because the rebar holds everything together. it doesn't really matter as far as the servicability of the slab. but having cracks occur in a joint looks better aesthetically than cracks at random locations in the slab. having 1/3 of the bars continuous thru the saw joint allows the slab to crack in the joint, but helps prevent the slab from settling differentially on each side of the joint. i've used this successfully many times over the years. |
|