Pozzolan is a finely powdered material which can be added to lime mortar to increase durability and, in the case of lime putty mixes, to provide a positive set.
The addition of pozzolan to any lime mortar (hydraulic or non-hydraulic) will modify its characteristics. Pozzolanic materials can combine with uncarbonated lime (calcium hydroxide) to form stable compounds, thus reducing the risk of early leaching or frost damage and increasing the potential durability of the mortar. Depending on the type of pozzolan chosen, the density and compressive strength of the mortar may be increased and porosity reduced. In general, the softer pozzolanic materials (such as brick dust from clay bricks fired at less than 950°C) will produce more permeable and flexible mortars, whilst the hard-burned materials, such as Blast Furnace Slag, will tend to produce a harder mortar, closer in its characteristics to cement.
Products available are:
Argical M- The Argical™-M range provides a broad range of benefits in lime mortars and plasters, range of metakaolins are manufactured through the calcination of kaolin to form an amorphous pozzolanic white mineral additive.
This material is gauged at 10:1 by volume.
- Technical Documents
Helps to aid a positive set
Reduces the risk of early leaching or frost damage
Increases the potential durability of the mortar
Addition of Brickdust produces more permeable and flexible mortars
Blast Furnace Slag produces a harder mortar
Where can I find out more about Pozzolans?
For detailed information about the use of Pozzolans for lime mortars, see: