Experimental investigation of spiral geogrid stirrup application in reinforced concrete beams

Reinforcement of reinforced concrete beams only against bending moment effect is not enough to provide its strength. It is also necessary to ensure the strength of the beam against the shear force effects. A beam without adequate shear reinforcement may break under increased load with cracks at a slope of approximately 45° with the horizontal formed in the regions close to the supports without reaching the bending strength. Up to a level, concrete compensates the principle shear stresses that make up these cracks. Principle tensile stresses, on the other hand, cause oblique tensile cracks; if there is not enough shear reinforcement to take the oblique tensile, the cracks widen and the beam breaks abruptly. The main objective of this study is to examine the effects of geogrid material on structural behavior of reinforced concrete beams when using geogrid material instead of steel as cross-section reinforcement and placing them in helical form at different angles. Geogrid beams, which were placed at 30, 45, 60, 90 degrees and without stirrups, were produced and these specimens were examined under four point loading test.