Behavior of concrete beams reinforced with fiberglass composite rebar under load

Строительная механика

Fiberglass composite reinforcement has been used in Russia for a long time, but there is still not enough research and necessary related data. Therefore this paper focuses on how exposure to loads affects concrete beams with fiberglass composite and metal reinforcement. The concrete beams samples (80×160×1400) were tested for bending as single-span hinged-supported elements. The load was applied within 20 seconds intervals in order to prevent relaxation of the concrete. All samples collapsed along the cross-section having maximum crack opening in the area of pure bending. The experiments show that the nature of beam collapsing and cracking does not depend on the type of reinforcement. However, the maximum crack opening width for beams with fiberglass composite reinforcement is 28.8 % greater than for beams with metal reinforcement. The value of the maximum deflection for fiberglass is 43.3 % greater. In addition, despite the initial experimental condition of equal loading onset time, the value of the crack formation for beams with fiberglass composite reinforcement is 15.5 % less. The average value of the breaking moment for beams with fiberglass composite reinforcement is 18.06 % less. Taken together, the data obtained in the course of the experiments suggest that the bearing capacity of the elements with fiberglass composite reinforcement, bent along the cross-section, decreases due to the low stiffness of the element itself. Therefore, this type of reinforcement is likely to be applicable for concrete structures on the elastic foundation.