Effect of SHEAR SPAN-TO DEPTH RATIO OF Concrete Beams Reinforced with GFRP bars on Shear under Fire Exposure
DOI:
https://doi.org/10.56830/IJSIE06202301Abstract
ABSTRACT:
Glass bars for concrete reinforcement, known as glass fiber-reinforced polymers (GFRPs), are new natural inorganic materials with distinct mechanical properties that have been used recently in the construction field. Generally, the FRPs bars have no yield before the brittle failure as steel bars and their behavior, when exposed to fire, is still under investigation, this paper presents an experimental study to get more knowledge about the characteristics and the fire resistance of a concrete beam reinforced using GFRPs. Three-scale concrete beams were constructed and tested up to failure under direct fire at 500 ◦C for an hour. Shear span-to depth ratio is the main parameter of this study. Beam (B1) had distance from face of support 670 mm ,beam (B2) had distance from face of support 250 mm and beam (B3) had distance from face of support 500 mm .All beams had 30 mm concrete cover , exposed to fire for an hour and three GFRPs reinforcement bars were used. The results are discussed in terms of load capacity, cracking behaviour, and failure modes.
Moreover, the experimental results are compared with theoretical calculations according to the ACI code and other codes. The results show that when distance from face of support over effective depth greater than 2.5 the beams act as slender beams while distance from face of support over effective depth less than 2.5 the beams act as arch action. Our results also showed that when distance from face of support over effective depth 2.02 the failure load incress by percent 60.3% and beam failure as shear failure while distance from face of support over effective depth 1.01 the failure load incress by percent 221.7% and beam failure as flexural failure . More studies are needed to justify our observations in details and determine their applicabilities under different conditions.
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