huangyhg

pile cap reinforcing
i have been consulted to review the following situation. here is what i have. a square pile cap 8'-6" x 8'-6". the piles are on a 4'-6" square pattern with 2' from pile to edge and 18" round concrete piles extending 4" into the cap. the pile cap is 3' thick with reinforcing 2" clear above the top of the piles. apparently, the bar detailer did not pick up on the 180 degree hooks for the reinforcing which is 9-#8 ea. way. these caps were poured with this "straight" reinforcing. i have a set of plans and am just beginning to chase down the loads that are involved. w14 steel columns bear directly (grout) on top of the cap. i am at a loss as to how this slipped through the cracks, and the several sets of eyes that should have caught this. is there any remedy other than tearing these out and replacing? i should add that 6-#8 and 1-#9 extend from the piles to near the top of the cap.
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you may not need the hooks. from the information you gave, it seems as though you have enough development length for a straight bar.
i think you may have a problem.
9#8 seems high for an 18" conc pile. i've often used a single 20m (like a #6) for 18" and 15m for 16" unless there is flexure involved. if the load is axial compression only, the concrete bearing at the pile/cap interface should be adequate to transfer the load.
dik
all buildings have to resist lateral load. if a pile foundation is used, each pile in the pile caps that resist the lateral load will have moment in them, due to that lateral load.
the pile cap had 9-#8 each way, at what location? i am visualizing reinforcement in two mats top and bottom, but that is not exactly what you said.
at any rate, the only fix i can think of is to convince yourself you don't need the 180 degree bends. if signicant bending or tension is being transferred from the column, it might be hard to convice yourself of that. compression only? that might be easier to swallow. maybe not all will have to be replaced?
lkjh345 is correct.
sorry... cap rebar not pile rebar...
if the ends of the #8 bars are within two inches clear of the side walls, then chipping in 4-5" will expose enough bars to weld a cross bar for a mechanical development of the existing bars. cast back a repair cover and leave the majority of the pile cap intact.
thanks for the prompt replies and advice.
civilperson: the plans (who looks at those anyway?) call for 2.5" clear. i am leaning toward a solution such as this.
what's the moment at the face of the column, and is there enough development to that point? it seems that there is plenty to develop the bars. i usually put 90 degree hooks for added safety, but for the most part i've seen straight bars working just fine.

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