Mix Submittal Question?

[Labratt1]

I am the quality control manager for a producer and I have a question. More specs are asking for trial batch data lately and it seems to me to be redundant since the mixes I usually submit are standard mixes that have 30+ independent lab test results. Yet I have had engineers deny the mix till I can run a trial bath even though we run trial batches on all our mixes once a year in the winter. They say the trial batch has to be more recent. I was wondering what the purpose of running a trial batch for each and every project served? If anyone can answer this I would be most appreciative.

 

[Ron]

Labratt1...If you are working under the International Building Code and its referenced document ACI 318, then trial batches are only required if you do not have statistical validation information. If you are running the same mix design and you have moving average statistical data, that is acceptable under ACI 318.