Influence of Heating Envelope on Structural Fire Integrity of Ferrocement Jackets

The structural fire integrity performance of ferrocement jackets was experimentally determined based on its flexural characteristics and the damage after exposure to fire. The main parameter investigated was the heating envelope, consisting of short and long heating durations of 3 and 63 h, where the maximum temperature in both cases was 1060°C. A sandwich-sample configuration was adopted to simulate the actual conditions of exposure to fire. Test results showed that using ferrocement jackets provided a satisfactory solution for fire protection due to improved post-fire strength as compared with that of plain mortar for both heating envelopes. An increase in wire mesh content significantly improved the mechanical properties of ferrocement under normal conditions; however after fire exposure the content of wire mesh was no longer significant regardless of heating duration. It was also found that higher volume fraction of wire mesh resulted in in-plane cracking. Mortar covers had negligible influence on the mechanical properties of ferrocement jacket exposed to fire for both short and long duration. With regard to failure patterns, it was found that long duration heating caused more severe skeletal steel-induced crack but less mortar spalling.