Hi everyone,

Building foundation walls with standard 8" hollow blocks and vertical rebar through the cores spaced every 4'. The spaces that have rebar need to be filled with grout. 'Grout' used in this context is new to me - my understanding is that is has very low slump so that it is easy to pour into holes without forming voids. The extra moisture apparently also allows for the high absorption into the block (again, this is my limited understanding).

My question is - how would I mix this on site? Is it simply watered down concrete? What size aggregate? I would assume that this could be specified to a concrete company and delivered as ready-mix but I'd like to avoid the delivery and small-load charges - and will also need to fill as I go in some places rather than doing it all at once when the walls are built. I see quikrete has a 'block-filling grout' mix on their website but I've never seen it in stores.

If anyone has done this on site or has a better understanding of the whole concept I'd appreciate any info you could offer.

Thanks

Hand filling block is very time consuming. Grout has sand, not aggregate per se. I would suggest a concrete company come and pump the block cavities. They could also vibrate the block to eliminate any voids.