FW: Cob: clarification on Quick lime vs hydrate

[Matthew HALL(SED)]

I cannot agree with the following statement made on the coblist:

>all quick or hot lime is is slaked in water before it can be
>> used,
quicklime which has been slaked IS hydrated lime. Lime (calcium carbonate; CaCO3) is heated to
drive off carbon dioxide producing CaO or quicklime. This is highly reactive and when slaked with
water produces hydrated lime. It is not then quicklime (CaO) because it has been hydrated in water.
When quicklime is added to soils of a high clay content it has the effect of drying the soil and
increasing its suitability for use in earth construction despite the high clay content.

Matthew

____________________________________________________________________
Matthew Hall - PhD Research Student
Centre for the Built Environment
Unit 9 Science Park
Sheffield Hallam University
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