Maximum distance between expasnion joints i open aur above grade parking structure
Maximum distance between expasnion joints i open aur above grade parking structure
(OP)
What is the maximum distance between expansion joints (or from an expansion joint to the end of the structure) that structural engineers are using these days, for above grade open-air single story parking structures of cast-in-place reinforced concrete? The joint seal must accommodate both thermal and concrete shrinkage movements. "Pour strips" that are placed some time after the adjacent concrete can help the shrinkage issue, but only to a limited extent, since at 28 days only about 30% of the long term shrinkage will have occurred, and anyway contractors do not want to leave pour strips open more than 7 days. Pour strips of course do not help at all with thermal movements.






RE: Maximum distance between expasnion joints i open aur above grade parking structure
They can be left "open" for in-plane movements whilst still supporting vertical loads. They are "locked" based upon construction durations/schedules.
RE: Maximum distance between expasnion joints i open aur above grade parking structure
That's PT which would have had a greater shrinkage component than RC. The concrete was specified with a 600 microstrain and I forgot what the shrinkage test came back as but I think it would have been around there.
The joints are properly covered and shouldn't fill with debris so the shrinkage would offset any thermal expansions. The slabs were placed with a 10mm inital gap and they have grown to around 60mm now.