Deterioration mechanisms of building materials and innovative ways to conserve them: case study - the medieval town of Rhodes

Abstract

Over the years, buildings made by stone and other porous materials suffer physical and chemical damages through absorbing water while exposed to weathering. Deterioration then occurs due to various intrinsic and extrinsic factors and urban environmental damage is very extensive, altering material’s form. A representative example of such case is the Medieval Town of Rhodes which suffers from loss of its aesthetic value owing to the disintegration of its building materials with extended architectural surfaces deteriorating from salt erosion and grain detachment.

Today, the Rhodian sandstone shows intense damage in most buildings through alveolar weathering and coordinated actions are needed for its preservation.

This paper highlights the need for a new conservation management plan based specific for Rhodes. The new conservation strategy should focus on the planning process of preservation of cultural heritage but also on a precise characterisation and mapping of decay patterns with an innovative approach to identify, describe and classify conservation problems. The physical and chemical properties of the building materials used within the conservation area of Rhodes are firstly investigated. A representative range of historic buildings are documented and studied to identify the common damages and propose either traditional or innovative consolidation treatments according to an extended literature review. This research gives an overview of a suitable method to assess deterioration patterns of stone and mortar.

Discussing organic and inorganic consolidating products traditionally used to regain the mechanical properties of decayed materials, will produce the basis for a cohesive conservation plan for the historic fabric of Rhodes. Many innovative techniques from other countries have been studied in depth to discuss solutions for the building fabric of Rhodes and finally a cohesive conservation management is proposed.