form removal for pile caps 1

[tw]

Contractor and testing lab having a disagreement on this, I don't remember every being asked about it.

Looking for guidance on two issues:

Form removal for pile caps - ACI 318 basically says do no harm and doesn't give specific time. There is a lot of discussion in ACI 301 about the issue but mostly for concrete that isn't a pile cap. Contractors generally do 24 to 48 hours around here (deep South). This contractor has been doing 24.

After form removal, contractor wants to backfill around the perimeter as soon as possible so as to not have an open hole for rain, etc. Testing guy says 3 to 7 days but he can't cite where that comes from. I don't see how the earth added back to side of pile cap could do anything negative. You aren't going to deflect or damage a massive pile cap. Lots of pile caps are earth-formed anyway so curing shouldn't be a reason either.

 

[DST148]

@tw> #1: Ref ACI One-Day Seminar - Troubleshooting Concrete Forming & Shoring: Basic form stripping times - Based on cumulative days or hours during which the surrounding air is above 50F:
Walls - 12 hours
Columns - 12 hours
Beam and girder sides - 12 hr
Unless explicitly stated in the contract documents, removal of forms for the vertical elements like walls and columns after 12 to 24 hours is quite common.
#2- Backfilling - Unless stated in contract documents, backfilling around pilecaps and footings after twenty four hours should not be a problem. Generally dimensional tolerances and formed surface defects is not a major issue for buried members like pile-caps and footings.

 

[hokie66]

The testing fellow needs to get a life. How did he get involved in this, anyway? The contractor in this case knows what he is doing, and if there is a dispute, it should be the EOR making the decision, not the concrete tester.

 

[dik]

I generally let the contractor loosen them the next day and wait 3 days for removal...

Dik

 

[dik]

I shold have added that with the cold temperatures we experience in the winter months that, with heat, the pilecaps may not gain sufficient strength for several months.

Dik