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Colbyt Colbyt is offline
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Default Size of concrete mixer and water to add?

"scorpionleather" wrote in message
I'm a newbie to pouring larger quantities of concrete/mortar/cement. I
have a batch I'll need to mix of 3 100 lb bags white portland cement and 5
100 lb bags of tiny pebbles. What is the smallest size mixer I can rent
that will do this batch all at once? The local rental has 6 cu ft and 9
cu ft tow-behind mixers. How much water should I add initially? I am
afraid of accidentally adding too much water or if I'm too cautious and
add it too slowly maybe it would take away a bit from my troweling working
time. How long to leave it spinning round the mixer?

Considering you need sand also I doubt you will get it in one mix.

Without looking it I can't recall the recipe but something like 400-600
pounds of sand (or more) is needed for that much Portland.

BTW Portland is 94 lb bags.

Got up and got the book off the shelf.

A 5 cubic foot batch is:
105 pounds of cement
51 pounds of water
231 pounds of damp sand
315 pounds of stone

Water weights about 8 pounds per gallon. Start with less and temper it with
more if you need to.

So as you can see, you may want to revise your recipe a little.

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