Deterioration of limestones at Sehzade Mehmed Mosque and other monuments due to action of air pollutants in Istanbul, Turkey

Abstract

istanbul, the oldest city, embraces two continents. The former capital of three empires (Roman, Byzantine and Ottoman), today Istanbul honors and preserves the legacy of its past. Shell limestones of Upper Miocene age were used as building stone in majority of the monuments in Istanbul because of their attractiveness, availability and workability. The acceleration in deterioration of building stones in recent years has been attributed to air pollution. Deterioration of the limestones under polluted atmospheres has been investigated through petrographical, chemical and mineralogical analyses. These involved optical and electron microscopy studies, major element analyses and the X-ray diffraction method. The effects of deterioration on the physical properties of the limestones such as dry density, water absorption and porosity have also been determined. Studies have shown that action of air pollutants and changes in meteorological factors are the more effective factors than the petrographical and physical characteristics of the the rocks.