Multi-technique Characterizations of Marble Stones from Elefsis, Greece, and Soapstones from Grytdal, Norway in Accelerated Acid Weathering Studies
|Title||Multi-technique Characterizations of Marble Stones from Elefsis, Greece, and Soapstones from Grytdal, Norway in Accelerated Acid Weathering Studies|
|Publication Type||Conference Paper|
|Year of Publication||2015|
|Authors||Gebremariam, KFanta, Perakis, P, Schellewald, C, Theoharis, T, Kvittingen, L|
|Conference Name||18th European Conference on Analytical Chemistry (Euroanalysis 2015) - Poster presentation|
Studies on the effects of acid pollution were conducted on three types of stone samples: marble stone from Elefsis, Greece, and two types of soapstone from Grytdal, Norway. The Pentelikon marble stone from Elefsis used in columns at the archeological site in Elefsis where as the Grytdal soapstones for the construction of Nidaros Cathedral Church in Trondheim. The investigation is part of a larger project in which we attempt to estimate and predict stone erosion from weathering, in order to reconstruct earlier appearances and predict future transformations. The approach involves studies of accelerated weathering effects from salt, acid and freeze-thaw on stone samples, site exposure tests and successive high accuracy surface scanning of the monuments in which the stones have been used. For the simulation of the accelerated acid weathering two acidic conditions (nitric and sulphuric acids) at constant pH’s were selected. Loss in mass with time and the physicochemical changes on macroscopic and microscopic levels were monitored, including qualitative and quantitative estimates of the acid rain-induced surface recession. The stones were analyzed before and after exposure to the acidic conditions with a range of analytical techniques. The acidic solutions used in the acid weathering simulation were evaporated to dryness and the residue investigated to identify salts produced in order to shed additional light on the deterioration processes.