Hydraulic lime: an introduction
Practical Action
Minimum compressive 1.75 MPa after 14
1.25 MPa after 14 Average 1.7 MPa
strength
days and
days & 1.75 MPa after 7 days and 3.4
2.8 Mpa after 28 days after 28 days
MPa after 28 days
Soundness
Maximum 10mm
As for Class A
Mortar bars not to
expansion in the Le
expand more than
Chatelier test
1.0% in ASTM test
Note – not all the properties are specified in the standards are shown above. For more complete details
consult the relevant standards.
Indian Standard = IS: 712-1973 Building Limes
American Standard = ASTM C 141 – 67; Standard Specification for Hydraulic Hydrated Lime for
Structural Purposes
A simple test to determine whether a lime is hydraulic is to take a lump of the quicklime and
sprinkle water on it. If reaction starts within five minutes accompanied by hissing and spitting
the lime is unlikely to have any significant hydraulic activity. If the reaction begins after about
15 minutes and is not violent then the lime could be mildly hydraulic. If the lime lump has
collapsed to a powder after about an hour and the container has only become warm, not hot,
then the lime could be moderately hydraulic. If the lump has only partially turned to a powder
or has remained intact after an hour then the lime could be eminently hydraulic. It might then
be necessary to use boiling water to get any reaction going or even to grind the lump. On
hydration a high-calcium lime can show a threefold increase in volume while hydraulic limes
show volume increases which are much smaller. After hydration some water can be added to
the lime to give it the consistency of a potter's clay and the lime rolled into a ball and put in
water. If the lime is high in calcium or mildly hydraulic the ball will probably break up. For a
moderately hydraulic lime the ball should stay intact and after a month have the consistency
of a bar of soft soap. However, an eminently hydraulic lime would have become like a soft
stone which would be hard to scratch with a fingernail.
References and further reading
Alternatives to Portland Cement Practical Action Technical Brief
Lime - An Introduction Practical Action Technical Brief
Calculating The Energy Efficiency of Your Lime Burning Process Practical Action
Technical Brief
Methods for testing lime in the field Practical Action Technical Brief
How to Build a Small Vertical Shaft Lime Kiln Practical Action Technical Brief
A Small Lime Kiln for Batch and Continuous Firing Practical Action Technical Brief
Pozzolanas - An Introduction Practical Action Technical Brief
Small Scale Production of Lime for Building John Spiropoulos, GTZ,1985
Gypsum Plaster: Its Manufacture and Use, A. Coburn, E. Dudley and R.Spence,
Practical Action Publishing, 1989
Small-scale Lime-burning: A practical introduction Michael Wingate, Practical Action
Publishing,1985
The Small Scale Vertical Shaft Lime Kiln: A practical guide to design, construction
and operation, Kelvin Mason, Practical Action Publishing, 1999
Building with Lime: A practical introduction. Revised Edition Stafford Holmes &
Michael Wingate, Practical Action Publishing, 2002/3
A Case Study in Lime Production: Improved design of a lime kiln in Sri Lanka,
Practical Action Technical Brief
Lime Production: Traditional batch techniques in Chenkumbi, Practical Action
Technical Brief
A Case Study in Lime Production No2 Improved Techniques at Chenkumbi, Malawi.
Practical Action Technical Brief
Lime Production: A traditional kiln at Bou Noura, Algeria, Practical Action Technical
Brief
Lime Production: Traditional batch techniques in Pattará, Costa Rica, Practical
Action Technical Brief
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