Experimental study on the mechanical behavior of the elementary components of masonry walls at high temperature

Abstract

Predicting the behavior of masonry structures under fire exposure and anticipating their fire resistance are critical for brick manufacturers. The fire performance of masonry walls depends on the behavior of components like bricks and mortars, both traditional and thin-layer, at high temperatures. Understanding this requires studying masonry from the material scale to full-scale walls. This paper examines the mechanical properties of terracotta and masonry mortar at high temperatures. It also investigates the compressive and tensile responses of masonry pairs, and the shear response of masonry triplets with fired brick and masonry mortars. The findings show that fired clay’s flexural and compressive strengths increase with temperature, while the Young’s modulus slightly decreases. Conversely, the flexural and compressive strengths of masonry mortar, along with the Young’s modulus, decrease significantly, losing nearly 80% around 700 °C. The compressive strength of masonry pairs follows the brick’s trend with temperature. However, both pairs and mortar show a similar decrease in tensile strength as temperature rises. The shear strength of masonry triplets declines to about 40% of its initial value at 600 °C. These results are crucial for developing nonlinear numerical simulations to understand hollow brick masonry walls during fires.