THE ROLE OF TECHNICAL AND NATURAL SCIENCES IN STONE MONUMENTS CARE

Stone monuments maintenance requires the systematic approach which should be based on the cooperation among specialist through more branches, especially from humanities, natural and technical sciences. The main aim of this article is to present the benefit of the cooperation among geologists and civil engineers and share preliminary results of the Czech Ministry of Culture project DG20P02OVV021 “Stone surface topography and its application in stone element restoration field”. Historic stone surfaces often contain stonemasons tool traces as an undoubtable part of historical monument value. The study and protection of the testimony of past is therefore very important. As a part of our project, we are conducting field and laboratory research of historic stone surfaces bearing the original tool traces. The studied area is the Prague urban conservation zone for its stone monuments richness from Romanesque to present days. First, the geological research of the stone masonry surface is conducted in the cooperation with archaeologists. The tool traces are documented, and the state of stone is described. Because of the negative influence of weathering processes on the stone durability, respectively tool traces, we decided to monitor the chosen historical stone surface using the hyperspectral analysis. Based on the analysis results we will be able to better understand the behaviour of stone surface and traces on it during the time.

RESTORATION TECHNIQUES FOR THE HERITAGE BUILDING / KIRKUK QISHLA AS A CASE STUDY

National heritage buildings are considered as the memory of the cities and its civilization’s legacy. Such buildings are receiving more attention these days especially from architectures who are trying to restore them by using the proper techniques to bring them back to their former appearance to serve the community in the present time. From that point, the general goal of this research is to concentrate on the used techniques of restoring national heritage buildings by using the proper materials for the damaged or the collapsed parts as the restoration process differs from a building to another. All these points should be done according to the laws and protocols of UNSCO and ICOMOS to keep the authentic features of the building and pass it on to the next generations. This research deals specifically and practically with restoring the Qishla building in Kirkuk as a restoration sample. Some parts of that building collapsed recently and the research aims to save that building by studying the techniques of restoring it using the materials and building techniques of the era the building was built in. This research rises an important point, which is finding a general prospective of scientific and technical ways in restoring cultural heritage buildings which are made from stone specifically. From all that above the main issue that this research deals with is “The unclear techniques of restoring cultural heritage buildings in general and the restoration process of Qishla building with stone in specific”. Accomplishing the aim of this research lies in two points: First: Studying the rules which govern the restoration process of cultural heritage buildings. Second: Studying the restoration process of Qishla building and that includes; the restoration process with stone should be done by examining the chemical and physical features of the stone, durability of the used stone, conducting chemical tests in international labs as (ACMAE ANALYSES/ Canada) and the last step is to analyze and discuss the results to take final decisions.

RECYCLING OF AURIFEROUS ORE FLOTATION TAILINGS IN SLAG-ALKALINE CEMENT

Research analysis aimed at stabilizing processes in industrial waste and other, similar hazardous ion containing materials, shows that these materials can be successfully stabilized, if they are bound as a mineral component in cement. Considering that auriferous ore flotation waste contains heavy metals that are useless for any production and accumulated in dumps, storages and sumps, this impairs the ecology of the country. This is why current study is conducted on recycling of auriferous ore flotation tailings by binding it as a cement component, which is also can be one of its effective applications. For heavy metal bonds stability evaluation in the composition of the cement matrix, the method of leaching elements by atomic spectroscopy was applied. According to the research it was found that application of slag-alkaline viscid systems for recycling of auriferous ore dump flotation tailings provides considerable advantages over traditional Portland cement systems based on PC I-500. It was shown that along with the physical blocking in the artificial stone matrix, based on slag-alkaline viscid systems, elements of heavy metals were also bound chemically as a part of structure-forming compounds. In this regard use of auriferous ore dump flotation tailings (10…30 %) in the compound of slag-alkaline cement results in the prolonged solidification and provides the same level of cement stone durability as the check sample compound.

Considerations on Granite Dimension Stone Porosity and Modifications from Quarry to Slabs

This paper presents the physical and petrographic characterization of selected granitic rock types from several quarries in Brazil and aims to contribute to a better knowledge of the engineering properties of granite dimension stone, focusing on laboratory physical determinations and the possible changes that would occur along processing operations, i.e., from the quarried rock to the polished slabs or tiles. The tests – petrography and porosity determinations – led to the collection of parameters of in natura and processed rock material, respectively from specimens obtained from small cubic blocks and polished slabs, situations considered representative of the stresses to which the rock is submitted to during the several processing stages. The results indicated that porosity tends to be higher for “tiles” than for “blocks”, and that “S-type granites” have higher porosity/open-pores values than “ordinary granites”, mainly due to their conspicuous microcracking. Moreover, in spite porous configuration may be modified during stone processing, it was found that such changes are not homogeneous and intrinsically associated to the petrographic characteristics, as previous microcracking and alteration states. Finally, as the new physical conditions, acquired after processing, may influence the stone durability, it is strongly suggested that they should be taken into account, as an additional criterion, to the cladding or flooring natural stone selection and specification.