In situ investigation of stone heritage sites for conservation purposes: a case study of the Székesfehérvár Ruin Garden in Hungary

Abstract

This paper demonstrates the application of in situ diagnostic tools to document stone heritage sites prior to conservation interventions using a Medieval ruin of Central Europe (Székesfehérvár, Hungary). The applied methods included lithological mapping and characterisation and mapping of decay forms as well as in situ measurements of physical parameters such as Schmidt hammer rebound, moisture content and micro-drilling resistance. The combination of these methods allowed the condition assessment of different lithotypes and demonstrated the role of micro-fabric, mineralogical composition and climatic conditions in stone durability. Differences were found in the properties and in the weathering forms of fine-grained and medium-grained porous oolitic limestone and travertine. The black crust observed in porous limestone is less prone to detachment on medium-grained oolitic limestone ashlars, while scaling was observed on fine-grained oolitic limestone blocks. The micro-drilling resistance of exposed porous limestone showed higher drilling resistance at the crust zone (upper 1-2 mm) than below, marking the upper cemented zone, while the drilling resistance of porous limestone under shelter showed an opposite trend. The shelly limestone, the sandy calcarenite and red compact limestone also showed an increase in drilling resistance at the topmost app. 2 mm zone. The applied in situ, non-invasive and micro-destructive techniques helped in the identification of endangered zones at Székesfehérvár, thus, they can provide key information on condition assessment of stones at heritage sites, where sampling is limited and preventive conservation is important.

Architectural Heritage Conservation in Nigeria: The Need for Innovative Techniques

“…Conservation of architectural heritage is preceded by proper assessment of its structural elements and material to determine the causes of decay and its degree as well as the appropriate conservation measure to be applied [10,29]. The preliminary assessment is done by visual observation, by which conservators and architects evaluate decay only with naked eyes without any instrument.…”

“…Despite this approach, the use of innovative methods is lacking in various conservation management plans for architectural heritage in Nigeria. Studies [9][10][11] have shown that the holistic use of innovative technologies as a complement to the traditional conventional methods boosts the efficacy of both methods for conservation purposes. The benefits of the proper application of traditional conventional methods lie in the principle of using materials that are of the same type as the deteriorated ones during conservation [12].…”

Petrographic and petrophysical characterisation and structural function of the heritage stones in Fuwairit Archaeological Site (NE Qatar): implications for heritage conservation

“…Characterisation of representative walls is fundamental to understanding the structural behaviour of a wall (Theodoridou and Török, 2019). Coursed rubble is the cheapest and roughest type of stone masonry.…”

Comparison of Latest and Innovative Silica-Based Consolidants for Volcanic Stones

“…or extrinsic factors of decay (microclimatic conditions such as temperature and humidity changes, water/moisture transportation, air pollution, biological activities, etc. ), enable planning the most appropriate strategies needed to reduce weathering of stone [ 18 , 19 , 20 ]. The conservation of historic and culturally relevant stone artworks and buildings involves the on-site protection and/or restoration, usually achieved by re-establishing grain-to-grain cohesion of damaged stone through the application of organic polymers, alkoxysilanes or inorganic consolidant compounds [ 15 , 21 , 22 ].…”