Performance of Laced Reinforced Concrete Beams with Different Ratios of Glass Fiber

This research experimentally studied the performance of laced reinforced concrete (LRC) beams with different ratios of glass fiber subjected to bending loads. These beams were reinforced by innovatively welding longitudinal bending reinforcement with shear stirrups at an angle of 45º. First, the effect of different glass fiber ratios on concrete properties, such as compressive and tensile strength, was studied. Then, four beams, a plain concrete beam, an LRC beam, and two LRC beams with 0.5% and 1% glass fiber were tested under bending. All beams had cross sections of 150×150 mm and a length of 1050 mm. The load deflection, stiffness, ductility, and crack width between these beams were compared. The experimental results showed good performance in terms of load and deflection curves for all LRC beams. The maximum load of the LRC beam was 34 kN with ductile behavior. LRC beams with glass fiber ratios had a maximum load of 35 kN; however, they were stiffer than LRC beams without fiber. Also, the LRC beam, compared to the plain concrete beam, showed an increase in strength about two times while the ductility improved about 1.6 to 2 times. Meanwhile, adding glass fiber to LRC beams had approximately the same strength and ductility as the LRC beams; however, it reduced the crack width from 2.63 mm to 0.92 mm.