huangyhg

concrete strength of drilled pier/pedestal
how long should a contractor wait after pouring a drilled pier/pedestal with embedded anchor bolts before placing the steel beam-column on it? the gravity loads are pretty minimal, but the moments under a wind load are pretty high.
basically, i suspect that my situation is similar to what the billboard erectors would experience. can anybody shed some light on how long concrete should cure prior to subjecting the foundation to any loads?
thanks.
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hopefully you have taken concrete specimens and can do strength testing at intervals until you have the necessary strength.
if you are only erecting steel framework, you will not likely have loads that approach the design loads for at least the initial 28 days after concrete placement, so you should achieve f'c by then.
check the mix design and strength gain curves that can be provided by the concrete supplier. these should give you an idea of the compressive strength vs. time.
i would say maybe 3 days for building columns, about a week for signs and billboards, but i have seen big signs erected the next day. scary.

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