A Simple Method and Its Optimization Method for Shear Reinforcement of Deep Reinforced Concrete Beams Embedded with CFRP Bars

Abstract

The invention discloses a simple method and optimized method for shearing-resistant reinforcement of a reinforced concrete deep beam by embedding and mounting CFRP bars. A pull-pressure bar model is established based on the stress characteristic of the deep beam and is used as a calculation model of a reinforced concrete deep beam; internal force flow distribution and surface strain distribution of the reinforced concrete deep beam are obtained based on numerical simulation and DIC measurement and a corresponding stress trace diagram is drawn, and an embedding and mounting position of a CFRP bar is determined; the volume ratio of the tow strand number and an epoxy resin adhesive in the CFRP bar and the cross section size of the CFRP bar are determined by an experiment; an effective embedding and mounting length of the CFRP bar is determined by an experiment; and a reinforcement plan of the reinforced concrete deep beam is formulated based on the determined embedding and reinforcing position, the cross section size, and the effective embedding and mounting length of the CFRP bar and then reinforcement is carried out. With the method disclosed by the invention, the internal force flow transmission path of the reinforced concrete deep beam is disclosed clearly; and the effective shearing-resistant reinforcement of the reinforced concrete deep beam is realized. On the basis of thetwo disclosed plans, the shearing-resistant bearing capacity of the reinforced concrete deep beam is enhanced by 45% and 65% respectively.

Description

technical field [0001] The invention belongs to the field of reinforcement of existing structures in civil engineering, and in particular relates to a method for embedding and pasting CFRP tendons to resist shearing and strengthen reinforced concrete deep beams. Background technique [0002] In my country's current design code for concrete structures (GB50010-2015), according to the beam-span-height ratio l 0 The difference in / h classifies the beams. where l 0 Single-span simply supported beams or multi-span continuous beams with / h<5 are generally called deep flexural members, and l 0 / h≤2 single-span simply supported beam and l 0 Multi-span continuous beams with / h≤2.5 are called deep beams. Because of its high bearing capacity and high construction efficiency, it is widely used in the conversion layer structure of high-rise structures, high-speed railway bridges, load-bearing components of marine constructions, and side walls of large shallow warehouses. [0003]...

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Problems solved by technology

[0004] After the deep beam is loaded, its actual mechanical characteristics do not conform to the simultaneous occurrence of beam and arch effects stipulated in the "truss arch" model in the current code, so that it cannot meet the deformation coordination relationship assumed in the current code, and the beam, arch In the ultimate bearing capacity calculated and determined under the condition of joint action, it is difficult to determine the proportion of the two effects, which leads to unclear stress conditions inside the structure, unclear tension and compression areas, and it is difficult to formulate effective reinforcement based on this. and fixes

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