Definition
Controlled heating of calcareous rock produces reactive lime, transforming natural rock into a workable raw material for binders.
Early evidence
High-quality lime plaster from burials at Nahal Ein Gev II, dating to about 12,000 years ago, indicates that relatively developed heat-treatment and plaster-making processes were already in use. This entry converts that date approximately to around 10000 BCE.
Relationship to related technologies
Burning produces lime, while mortar technology concerns its further proportioning and use. The process relies on controlled fire, but this does not justify classifying it as a direct evolution from any particular metallurgical route.
Principles and impact
Problems solved
- Transformed rock into a material that can be mixed with water, shaped, and then hardened.
Principles
- High temperatures decompose calcareous raw materials; subsequent addition of water produces a workable lime paste.
- Temperature, fuel, and raw-material processing jointly affect product quality.
Improvements
Not recorded
Significance
- Extended the use of fire from direct heating to deliberate material transformation, providing raw materials for lime-based binder systems.
History and applications
People
Not recorded
Organizations
Not recorded
Events
Not recorded
Applications
Raw material for lime plaster、Raw material for lime mortar
Limitations
- Requires sustained heat, and limestone decomposition releases carbon dioxide.
- The date of archaeological remains cannot be equated with the date of the original invention.
Upstream and downstream relations
Upstream
Downstream
Sources: Lime plaster cover of the dead 12,000 years agoPreservation Brief 15: Preservation of Historic Concrete
Sources: Lime plaster cover of the dead 12,000 years agoMortar, Unsung Hero of History