The Conservation Section’s concern is with the damage that appears on the surface of the monuments and is a result of the internal structure of the marble, environmental factors and human interventions.
The works of surface conservation, are in process on all the monuments and sculptures, since 1987 and, they are in close coordination with the structural restoration programmes. They comprise a distinct project, carried out by conservators, marble technicians and conservation technicians. The scientific backbone (bedrock) for this work was provided by the extensive research carried out at the National Technical University of Athens (N.T.U.A.) by the late professor Th. Skoulikidis and his team colleagues as well as from the international literature. The methods and the materials are constantly improved through new information from the work itself and from interdisciplinary collaboration with specialists.
The main building material of the monuments is Pentelic marble, the main component of which is calcium carbonate. The foundations are of limestone. Monochromatic surface layers are maintained on the marble surface. The layers can be distinguished in the inner “epidermis”, usually orange-brown layer totally adhered to the marble and in the outer ”coating”, which is off-white and covers the “epidermis”. The main components of the “epidermis” are calcium oxalate and calcium phosphate; the outer ”coating” is calcium carbonate. Inscriptions and graffities of earlier historical phases are preserved on the surface of architectural members and sculptures. Vestiges of painted decoration like red colour (hematite), blue (Egyptian blue), blue-green (malachite-azurite) and polychrome can be observed. Moreover traces of painted patterns with preliminary incisions are maintained.
The materials used in conservation are inorganic with physico-chemical and mechanical properties compatible with those of deteriorated marble. Wherever reinforcement with metal clamps or dowels is necessary, titanium is used. Organic materials have been ruled out because they have a limited life-span, they are affected by ultra-violet radiation and they are not compatible with marble.
The necessary work-site infrastructure and suitable equipment has been provided so that the works can be safely carried out.