Experimental characterization of the weathering of stone masonry due to wet and dry cycles and salt crystallization cycles

Abstract

Considering that by 2050 the effects of climate change around the world will cause extreme conditions for the built environment, particularly for historic masonry constructions, it is important to understand in more detail the effect of different environmental conditions on the durability of masonry of stone. In this work, an experimental characterization of the deterioration process of the stone masonry submitted to wet and dry and salt crystallization cycles is presented and the results are discussed. For this, the effect of these condi-tions on the mechanical behavior under compression of stone masonry was evaluated. For the tests, samples composed of two and three units respectively were adopted. The experimental campaign was divided into two phases: (1) water absorption cycles by capillarity (clean water and water with a concentration of 3% and 10% sodium chloride) and drying cycles in samples at 60ºC. Sodium chloride was selected because it is of-ten found in old buildings subject to cycles of humidity. For this, a special setup was designed to perform the immersion and drying of several samples at the same time, controlled by moisture and temperature sen-sors; (2) mechanical characterization of material and masonry assemblages under uniaxial compression tests after the cycles. From these experimental tests it was possible to evaluate the effect of the exposure condi-tions on the mechanical properties of the materials and masonry assemblages.