best mix for DIY void filling

I have been reading about flowable fill and self consolidating concrete-all looks great,but you have to buy from ready mix.Grout non shrinking from home depot is $12 a bag.I need wet pourable material I can pour from a pail to fill voids animals made under drive,under pole barn and shed.I can get quikcrete 5000 for much less.I know if I mix too much water it will weaken concrete,thats why the grout may be best no matter cost.I only have two areas where strength matters and that the level tunnel under concrete drive,and the pole barn.The pole barn holes slopes sharply down.Any cement contractors out there,or someone who has done this before? I rally want to know if I can mix any cement product to flow easily from a pail,or will that be too weak of support under drive.The tunnel is approx 1 ft diameter and 20 ft long.Thank you for your suggestions!

 

What you are doing won't matter in the realm of "weakening" the concrete. You aren't building on it, just filling holes. Now, with that said, making it "pourable" will require some sort of damming effect to keep it from backflowing in the yard. Could you not use it as concrete and make it a little loose and throw it in the areas with a mason's trowel? IF your drive is in jeopardy, then it may be best to call in a pro to pump it hydraulically to restore the footing effect the ground was giving it in the first place. Others will have more viewpoints so hang in there.

 

When I said weaken the concrete, I meant weaken the support under it.I know I can buy $12 a bag quikcrete non shrink construction grout and it will pour from the pail.I would use another quikcrete product that costs much less and just mix it wet so that its pourable.I dont want to do that if it weakens the mix under say 4000psi.Thats what I want to ensure.Thank you for your help!

 

Sorry to the bearer of bad news, but pouring grout from a pail will never fully travel and consolidate to the end of a 20' tunnel--you'd be lucky to get it 5' or 6' in. Pay a mud-jacking outfit to place their material all the way in, removing sections of hose at the pump end (and reconnecting) as they pull them out. Even hand-pumps designed to move grout won't push it that far (at least the few types I've used).