Acoustic emission based damage limits and their correlation with fatigue resistance of refractory masonry

During service in industrial furnaces, refractory masonry is exposed to cyclic thermal strains. Fatigue is a frequent cause of structural failure. In this study, displacement-controlled cyclic tests are applied to quantify the fatigue resistance of two silica-based products demonstrating different brittleness at failure. Limits for displacement producing critical damage were obtained from Acoustic Emission (AE) data. CALM and LOAD ratios, obtained from short-term cyclic tests, were used for this purpose. A correlation was found between experimental fatigue curves and AE-based damage limits. Less brittle material was found to be more susceptible to fatigue degradation in the broader amplitude range.