During placement, the crew requests 15 gallons of additional water. The producer confirms that the batch has already received its full permitted design water, with zero allowance remaining. What response follows from this condition?
- AAccept it; water added at the site is a normal adjustment and the strength of the mix is set at the plant, not on the job
- BAccept it; the mix will still reach the specified strength provided the crew vibrates the concrete thoroughly after placement
- Reject the addition; the strength depends on the water-cement ratio, so water beyond the design allowance must not be added
- DReject the entire load; once any water is added at the site the concrete is no longer the mix the plans specify
Where to look it up
https://www.nrmca.org/association-resources/research-and-engineering/frequently-asked-questions-on-concrete-materials/
Why C is correct
Reject the requested addition because it exceeds the confirmed design allowance. The issue is not simply that water would be added onsite. NRMCA allows qualifying adjustments when required slump has not been reached and design water is not exceeded; additions must be documented. This finding does not by itself require rejecting the entire load or predict its measured strength.