Laboratoryjne badania procesu deterioracji trawertynowych elementów konstrukcyjnych

Aging of masonry objects results in deterioration of strength parameters and building and decorative value of stone. This slowly developing process can be modeled in laboratory, which makes possible direct observation of destructive impact of atmospheric pollution and salty water or acid rains in the course of artificial seasoning. The paper presents results of analysis of artificial aging of travertine under influence of frost, high temperature and crystallization of salt solutions. The tests were carried out on fresh samples of travertine collected in quarries at Raciszyn in Poland and Hierapolis in Turkey. Travertine extracted from in these quarries was used in the past and is still used as building and decorative stone in masonry works. Comparative method of detecting micro-structural metamorphose was performed with the application of microscopic analysis (SEM) and the strength and ultrasonic diagnostic analyses. The quantitative characteristics of deterioration state of travertine is described by the proposed deterioration index (I), based on nondestructive determination of wave propagation velocity in fresh rock sample (Vpo) and in the same sample under influence of sequential stages of modeled deterioration (Vpn) with respect to subsequent changes of compressive strength (Rc). According to test results, resistance of the Raciszyn travertines to frost, high temperature and crystallization of salt is about 2 times higher than in the case of those from Hierapolis.