Test of loaded and unloaded natural stone masonry walls exposed to fire.

This paper describes two full-scale tests carried out on two natural stone masonry walls subjected to fire loading, the first one was thermally loaded only (exposed to fire during 120 min without failure, then a natural cooling phase was observed) while the second one was thermally and mechanically loaded (exposed to fire and loaded up to failure with a compressive force at its bottom end). The experimental results showed that the thermal bowing was greatly affected by the in-plane mechanical loading. A water vaporization plateau at about 100 °C has also been observed, showing the influence of the hydric phenomena on the temperature distribution across the wall thickness. Analysis of cracking and failure of the walls showed that crack initiated in the vertical joints and propagated vertically through the blocks, which is quite typical for masonry in compression. Furthermore, the observed fire behaviour of natural stone masonry walls has been compared to the fire behaviour of newer, manufactured materials such as hollow bricks, concrete blocks or reinforced concrete walls. [ABSTRACT FROM AUTHOR]