Lime Chakki is an ancient method of producing lime plaster. The ring is 5m dia in which the stone moves in a circular path pulled by the bullocks. There are two types of lime. One is hydraulic lime(impure), used for mortar purpose and also exterior plastering and non – hydraulic lime (pure) which is
used for smooth finishing.
We get powdered lime i.e. Calcium hydroxide (slaked lime) on site which is used for construction activity. This lime absorbs CO2 from the atmosphere and again converts back into limestone or calcium carbonate.
In sacred groves, the usage of lime has been the backbone of our initiative towards Eco-building. Lime mortar production is done on-site, an alternative for cement mortar.
Preparation of the Lime mortar:
- Quarry Dust
- Kadukkai & Jaggery Water (Fermented)
Proportion for Kadukkai-Jaggery Mix
For every 700 litres of water 20kg of jaggery and 18kg of kadukkai powder. It should be stirred well and kept for fermentation for about 2 weeks.
The Lime Chakki process
Two mixtures are prepared. First mix of Lime & quarry dust in the ratio 9:15, second kadukkai & jaggery in the ratio 18:20 which is allowed to ferment for 4 weeks.
3 to 4 batches of lime & quarry dust mix is poured into the CHAKKI. Then the fermented kadukkai & jaggery water is poured over it for perfect grinding.
The ride on the tractor
The stone which is attached to the wooden log from the center is pulled by the tractor with a rope tied to its back. The tractor has to drive along the pit. Five to six people will stir the mix continuously with shovels and the rest of them enjoy the tractor ride on sitting on top of the tractor and vice versa.
Where Unity becomes strength!
Once the mix is ready it cannot be used immediately. We all unite together to transfer the lime mortar made from pit to storage tank with cheerful songs played in the speakers. It has to be stored for fermentation for 2 weeks.
Finally a hardworking day comes to end in a productive way.
Kamali Srinivasan, Intern