[brainanator]

Yeah, the concrete canoe team was bummed they couldn't use fibers since that was a big part of their work.

I might be able to get some fly ash from local concrete supplier. I don't think they have any superplasticizer.

I've been considering fly ash, but I find all over that it increases long term strength. We're looking at a curing time of only 32 days. (after the first day the concrete will be submerged to add strength) I think just using extra cement would be more beneficial than adding fly ash, based on what I have read so far.

thanks for the inputs so far. I think we will be pouring this Friday. Sadly we cannot test the mixes...