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Posted by DanG on September 22, 2007, 8:51 am
I think "they" will not have enough concrete to fill the forms. I
hate making bagged concrete pours, but occasionally they are a
necessary evil in the business. I make an accurate take off on
required volume and figure 80 pound bags at 1/2 CF. 40 and 60
pound bags are easier to carry and make the cost per bag look
good, but weight is weight. 60 plus 60 just won't make 150.
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______________________________
Keep the whole world singing . . . .
DanG (remove the sevens)
dgriff237@7cox.net
>> > On Sep 21, 7:24 am, teletub...@hotmail.com wrote:
>> >
>> >> How many 60lb bags of pre-mixed concrete will I need to make
>> >> a
>> >> 4 foot
>> >> by 4 foot sidewalk square at 4 inches thick? (16 sq.feet) I
>> >> only
>> >> found one web based calculator and it said I need almost 40
>> >> bags. That
>> >> cant be right. Heck, the bags are close to 4 inches thick
>> >> and
>> >> they
>> >> are larger than a square foot. Math is not my thing....
>>
>> > 60lb=1/2cu ft
>>
>> No way. A cubic foot of concrete weighs between 140 and 155
>> pounds.
>
> I think they're saying that a 60 pound bag makes 1/2 CF of
> concrete.
> The bound water makes up the difference in weight.
>
> R
>
>
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