ACI reference / vibration of concrete after initial set

[boffintech]

ACI 301 5.3.6.5 Protection—.....Immediately after placement,
protect concrete from premature drying, excessively hot or
cold temperatures, and mechanical injury.

Mechanical injury....is there a more specific ACI reference that states not to run a 10 ton vibrating padded drum compactor within 5' of fresh concrete in column forms?

 

[cancmm]

Check paper entitled "Effects of Induced Vibrations on Early Age Concrete" by Dunham/Rush/Hanson, ASCE, 2007. Might have what you're looking for.

 

[msucog]

ACI 308 1.1.3 and 1.1.4
ACI 301 1.8.2

You could always insist the contractor pay for coring and/or ndt testing to confirm they're not damaging the concrete. However, let them know that you will choose the firm that performs the sampling/testing (the contractor pays). If the contractor refuses to listen to reason, that's when it's time to get highly technical on every aspect of the construction until the construction quality and procedures improve sufficiently to satisfy the EOR. I'd also suggest parking the testing firm onsite fulltime and give them instruction to be very proactive/inquisitive in to what the contractor is working on around the site then fully document, sample and test it. Perhaps that will help the contractor regain their sense of reason.

And where is my copy of "Common Sense for Contractors" when I need it? haha (I spent my first decade as a contractor and will atest that they can do some amazingly dumb things...whether intentional or not)