The impact of cyclic loads on physicomechanical properties of the massive and vesicular basalts

Abstract

Stone monuments are the most visible and essential structures of our cultural heritage; however, many of the historical structures around the world are now suffering from stone deterioration. Diyarbakır City Walls, which were acknowledged the status of World Heritage Site by UNESCO, are among the most extensive surviving structures from ancient times. The City Walls have also some deterioration related problems. Basalts having such different textural properties as massive and vesicular were employed as the principal material in the construction of the Diyarbakır City Walls. Weathering is strongly related to the climatic and environmental conditions of the site. In order to evaluate the physical deterioration, environmental conditions were artificially simulated in accelerated weathering tests such as wetting-drying, freezing-thawing, and salt crystallization. For this purpose, 180 massive and vesicular basalt samples were prepared. The effects of these tests were evaluated by visual examination, weight loss, effective porosity, dry and saturated unit weights, water absorptions under atmospheric and vacuum pressure, sonic velocity and uniaxial compressive strength. It is found that the salt crystallization is the most effective accelerated weathering test deteriorating the basalt samples most aggressively.