See http://en.wikipedia.org/wiki/Lime_mortar#Mix For the recipe details.
Lime mortar is a type of mortar composed of lime, an aggregate such as sand, and water. It is one of the oldest known types of mortar, dating back to the 4th century BC and widely used in Ancient Rome and Greece, when it largely replaced the clay and gypsum mortars common to Ancient Egyptian construction.
With the introduction of portland cement (OPC) during the nineteenth century the use of lime mortar in new constructions gradually declined, largely due to portland's ease of use, quick setting and compressive strength. However the soft, porous properties of lime mortar provide certain advantages when working with softer building materials such as natural stone and terracotta.
Pozzolanic mortar is a lime based mortar, but is made with an additive of volcanic ash that allows it to be hardened underwater; thus it is known as hydraulic cement. The Greeks obtained the volcanic ash from the Greek islands Thira and Nisiros, or from the then Greek colony of Dicaearchia (Pozzuoli) near Naples, Italy. The Romans later improved the use and methods of making what became known as pozzolanic mortar and cement. Even later, the Romans used a mortar without pozzolana using crushed terra cotta, introducing aluminum oxide and silicon dioxide into the mix. This mortar was not as strong as pozzolanic mortar, but, because it was denser, it better resisted penetration by water.
Mortars containing only lime and sand required carbon dioxide from the air to convert back to limestone and harden. Lime/sand mortars hardened at a slow rate and would not harden under water. The Romans created hydraulic mortars that contained lime and a pozzolan such as brick dust or volcanic ash. These mortars were intended be used in applications where the presence of water would not allow the mortar to carbonate properly(ref. iv). Examples of these types of applications included cisterns, fish-ponds, and aqueducts.
What is the secrets to building with lime?
We have tons of rock on our property that we want to put into shutters and pour a lime/soil mix in to build our workshop. We've seen this method working with building rubble and cement. So want to try this with rocks, lime and soil.
But it doesn't seem there is a "recipe" on how to make the lime mix.
Can anyone help pls?
Looks like the 3 lime : 1 sand is the general mix.
But looks like this mix applies only to sharp sand (builders sand).