Mechanical behavior of self-compacting fiber reinforced concrete at elevated temperatures

It is worth mentioning that the dense microstructure of the self-compacting concrete (SCC) makes it more brittle and thus less resistant to high temperatures. Therefore, it tends to fail due to spalling and development of cracks are rapid at elevated temperatures. In the present study, the influence of steel fibers on the mechanical properties of SCC after exposure to elevated temperatures are investigated. The effect of steel fiber (SF) on the mechanical properties including compressive and tensile strengths of SCC has been studied. Also, the characteristics of stress-strain curves for fiber reinforced SCC (FR-SCC) were discussed in detail. Experimental results have shown that the addition of SF leads to significant improvement in mechanical properties of SCC, particularly after elevated temperatures. The findings revealed that the polypropylene (PP) fibers were able to prevent the risk of spalling in SCC during heating processes. None of the respective previous studies have investigated the mechanical behavior of fiber-reinforced concrete corbels subjected to elevated temperatures. For this reason, the other aim of the present thesis is a novel experimental attempt to understand the behavior of FR-SCC corbels after exposure to temperatures. This study accounts for the ability of SFs to improve ductility and enhance mechanical behavior of RC-corbels after exposure to elevated temperatures. The results were presented in terms of load-deflection curves, crack patterns and failure modes. Experimental results showed that the SFs have a positive effect on load-carrying capacity and ductility of RC-corbels before and after exposure to elevated temperatures.