Composite bar-reinforced ECC and concrete composite beam and construction method thereof

Abstract

The invention discloses a composite bar-reinforced ECC and concrete composite beam and a construction method thereof. The whole cross section of the composite beam is in a rectangular shape, and the composite beam comprises a fiber-reinforced cement-based composite material with concrete on the upper portion and interval grooves in the lower portion and an FRP bar-steel bar framework; in the FRP bar-steel bar framework, longitudinally-tensioned FRP bars are placed at the bottom of the beam, located on the inner sides of steel bar stirrups and bound together with the steel bar stirrups, longitudinally-tensioned steel bars are placed on the upper sides of the longitudinally-tensioned FRP bars, and a steel bar framework stud is placed on the top of the beam, located on the inner sides of the steel bar stirrups and bound together with the steel bar stirrups. According to the composite bar-reinforced ECC and concrete composite beam and the construction method thereof, on one hand, through the superior tensile property of the ECC material and the tiny crack mechanism, the dampproof and rustproof purposes are achieved while the bearing capacity and ductility of the composite beam are significantly improved; on the other hand, by mixing the FRP bars with the steel bar, the high strength and the corrosion resistance of the FRP bars and the ductility of the steel bar are fully utilized. The composite bar-reinforced ECC and concrete composite beam can be applied to beam components in building and bridge structures.

Description

technical field [0001] The invention belongs to the field of composite structures in civil engineering, is suitable for beam components in buildings and bridge structures, and is a novel composite bar reinforced ECC and concrete composite beam component and a construction method thereof. Background technique [0002] At present, due to the low tensile strength of concrete, the reinforced concrete beams widely used in building structures often work with cracks in normal use. The existence of cracks will corrode the internal steel bars, reduce the stiffness of the components, and increase the deflection. Affect the normal use and durability of structures. At the same time, due to the great difference in the deformation behavior between steel bars and concrete, under the action of bending load, the concrete in the tension zone cracks at a very low stress level, and the stress at the cracks is borne by the longitudinal tension steel bars alone. Part of the tensile force needs t...

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Problems solved by technology

However, FRP reinforced concrete beams also have some shortcomings: due to the low tensile strength and poor crack resistance of concrete, and FRP is a linear elastic material, brittle failure will occur in the final member; and the lower elastic modulus of FRP tendons will make FRP tendons The cracks of reinforced concrete beams are too wide and the deflection is too large, which affects the normal function of the components; FRP bars are greatly affected by humidity. In a humid environment, the resin matrix of FRP bars absorbs moisture in the air through capillary action, resulting in The tensile strength, shear strength and bonding performance of the FRP tendon determined by the performance of the resin will decrease significantly

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