I recently was asked if I thought using coal cinders at the bottom of a hole
would be ok instead of gravel. He was going to use the cinders mixed with
sand and cement to pour his tower base.
The person had a large pile of the cinders on his property.
Emphatically no!
In the old days, the cinders left over from coal fired home boilers was
hauled away and eventually used as a base for concrete sidewalks and the
making of 'cinder blocks'.
This proved to be a problem. The coal cinders, had high sulfur content and
when combined with rain water would form an acid and eat the concrete from
underneath.
Same result to the 'cinder block'.
When this problem became known most building departments outlawed their use.
(what are commonly referred to as cinder block nowadays are really small
aggregate concrete block)
So, if you tear up an old driveway or walkway and think you can use those
cinders as a base for drainage or in your own hand mixed concrete....don't.
Anyone wanting to obtain brochures and specifications for mixing concrete.
Or obtain facts about additives, rebar placement etc.
Can obtain the information from the Portland Cement Association.
http://www.portcement.org/index.asp
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Why do the signs that say "Slow Children" have a picture of a running child?
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Bill H. in Chicagoland
w9ol@billnjudy.com
www.billnjudy.com
http://files.billnjudy.com
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