Israel Nature and Parks Authority
The Conservation of the Archeological Parks
The use of St. Astier Natural Hydraulic Limes
|First Preliminary Report|
|Prepared by Asi Shalom||September 2000|
The National Archaeological Parks of Israel include great and important epics of history from the beginning of humanity through biblical and classical times.
During the past century and in recent times, these sites were and still are archaeologically excavated. Although new finds shed new light on the mysteries of the past, it is evident that the greatest challenge is to conserve what has been exposed.
The fate of historical and architectural structures which have suffered destruction and abandonment but which still portray and hint at the culture and ideology of life of the humans who have built the sites, is at risk.
To conserve all these sites in the most authentic manner using comparable materials and minimal intervention and to maintain them for this and for future generations. This is the goal - this is the challenge!
Comparable and compatible materials
After many years of
the damaging use of incompatible, cementitious materials, the last decade has
seen the revival of mortars, plasters and renders made of lime or earth in the
conservation of archaeological sites. The use of cementitious mixes is not, however,
the only potentially damaging intervention. As incorrect is the use of non cementitious
materials that are assumed to be suitable by conservators or specifiers who, without
any research into the products, are relying on uninformed opinions or practice.
2000 year-old lime plaster, miraculously surviving and urgently awaiting conservation treatment.
Mosaic floor during careful conservation treatment.
Soft-stone facade deteriorated to point of collapse.
The use of St. Astier Natural Hydraulic Limes (NHL).
There is an urgent need to confront the forces of decay represented by changes and extremes in climates, exposure, neglect and damage caused by previous uninformed interventions with inappropriate materials ( including the use of weak materials in unstable surroundings or gauged with cement), large number of visitors, vandalism and so on. The use of St. Astier limes has given us the chance to work with these scarred structures providing compatible mortars that will preserve their historical testimony for future generations.
Having these limes as versatile binders for large and varying uses has given us the needed flexibility, a relatively simple and speedy application and long term durability: all these are vital elements in building national conservation and maintenance plans for almost 50 National Archeological Parks.
In almost 3 years of use, we have tested, applied and are able to make on-going assessment of the qualities and performance of these limes in mortars, plasters, renders, surface consolidation, flooring, sacrificial coatings, grouting, injection, casting and as an additive to earth mortars, in the conservation and restoration of structures ranging from fragile to solid, deteriorating to stable, minute to massive. These sites are of the outmost importance to be preserved for the future. Many of them are not only significant for Israel but belong to the historical, social and religious development of our modern society.
of the greatest challenges was an unusually large render panel in one of the grand
pools which was detached more than 10 cm from bedding and wall and miraculously
survived and waited for treatment.|
The pictures below try to depict the challenge:
of stone decorations:|
- Round column pieces - NHL-5.
- Masoned column base - NHL-5 + gypsum.
are some of the sites where the St. Astier NHL's have been pre tested and are
now being used and monitored on on-going conservation and restoration work with
professional conservators. |
Masada National Park:
National Park: |
A small site with international fame and mystery. Home of the Dead Sea Scrolls, an ingenious water system using run-off flood waters chanelled to fill a huge system of plastered cisterns. Excavated evidence points to a site of communal living although recent discoveries place it as a villa of a king's vassal from the 2nd Temple period.
An enormous challenge to conserve the plastered water system and exposed earth construction.
Sheva National Park: |
National Park: |
We are currently extending the use of St. Astier NHLs to many other Archaeological National Parks to aid in conservation of similar situations and contend with new, interesting challenges.
Our 3 years of experiment and experience have given us great confidence in the performance of these materials. There is every indication that their permeability, flexibility and durability will provide us with the necessary compatible materials to continue to preserve our exposed historical ruins, monument and sites.
A final remark to be made is on the role of the Authorities. They must be the ultimate guide in the choice of correct materials, recognice the work of good conservators and restorers and provide adequate funding for testing and research to preserve cultural patrimonies that otherwise could be lost forever.