[Strawbale] more hydraulic vs. hydrated lime

[Jeff Ruppert]

We have used NHL extensively and it is a great product.  We use it both 
straight out of the bag and also cut it up to 1:1 with hydrated lime to 
achieve longer working times in our very dry climate.  We have used both 
3.5 and 5. 

The term Natural Hydraulic Lime, or NHL, is a designation of quality.  
This is in contrast to artificial hydraulic lime which can be crafted by 
mixing hydrated lime with pozzolans or fine silica aggregates.  
Artificial hydraulic lime can be made by anyone through experimentation, 
or it can be found in various places from industrial processes.  For 
example, some sugar beet plants use hydrated lime to extract sugar 
during the process.  Due to the high silica content of the plant, the 
waste product is an artificial hydraulic lime - a mixture of hydrated 
lime and fine silica.  I have heard of the possibility of buying this 
very cheap from the sugar plants.  Some of the plants are already set up 
with bagging operations and can bag it for you.  The term I have heard 
this type of lime called is "sweet" lime, kind of as a joke. 

Other possibilities are to combine fly ash, rice hull ash, or I thought 
of sorghum husk ash, or any ash from plants with high silica content.  
You would need to experiment a bit to find the right combination.  There 
seem to be many possibilities, making the experimentation much like 
using earth plaster. 

I need to emphasize though, the NHL designation is one of quality and 
consistency.  You are taking matters more into your own hands by 
experimenting with mixtures.  The point is, there are many possibilities 
with a little imagination.

-- 
Jeff Ruppert, P.E.
Principal

Odisea LLC
Engineering and Consulting

Front Range Office 		West Slope Office		
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jeff at odiseanet.com
www.odiseanet.com