Composite frp bar, preparation process and preparation device

Abstract

The invention provides a composite FRP bar, a preparation process and a preparation device. The composite FRP bar comprises an FRP bar and a steel strand arranged at the center of the FRP bar, wherein the volume ratio of fiber bundles to a thermosetting resin matrix in the FRP bar is 2:1-3:1; the volume fraction of the steel strand accords with the formula of Eh=(1-alphas)Ef+beta alphas Es, wherein Eh is the set elasticity modulus of the composite FRP bar, Ef is elasticity modulus of the FRP bar, beta is a coordination coefficient and is more than 0.5 and less than 0.9, alphas is the volume fraction of the steel strand, and Es is the elasticity modulus of the steel strand. According to the composite FRP bar disclosed by the invention, the steel strand is added in the FRP bar, and the elasticity modulus of the bar is greatly improved. The preparation process of the composite FRP bar comprises the following steps: step 1. feeding yarns; step 2. impregnating; step 3. molding; step 4. winding into ribs; and step 5. heating and curing. The preparation device for preparing the composite FRP bar comprises a yarn rack, an impregnation tank, a threading plate, a molding die, a winding shaft, a heating channel and a traction machine, wherein the yarn rack comprises a fiber bundle fixing rack and a steel strand fixing rack.

Description

technical field [0001] The invention relates to a composite fiber-reinforced polymer (FRP) tendon and a preparation process and a preparation device thereof, in particular to a preparation process and a preparation device of an FRP tendon for civil engineering. Background technique [0002] As an important building material, steel bars have been widely used in structural engineering. However, a large number of engineering practices have shown that the use of deicing salt, harsh weather conditions and other factors are likely to cause corrosion of steel bars and steel strands, resulting in a decline in the durability of concrete structures. Fiber Reinforced Polymer (FRP) bars have the advantages of light weight, high strength, corrosion resistance, low relaxation, and good fatigue resistance. FRP bars are used as longitudinal bars, abdominal bars or prestressed bars in concrete structures. Improving the durability of concrete structures has good economic and social benefits....

AI Technical Summary

Problems solved by technology

For example, the cost of carbon fiber reinforced polymer (CFRP) tendons in FRP tendons is too high and the elongation rate is low, so it is difficult to be widely used, while the elastic modulus of lower cost glass fiber reinforced polymer (GFRP) tendons is small, and the use of GFRP tendons The rigidity of concrete components is low, and it is easy to cause damage due to cracks and excessive deformation; in addition, the shear strength of FRP tendons is low, and brittle shear failures are prone to occur under high tensile stress conditions

[0004] In order to improve the defects of FRP bars, relevant research has been carried out at home and abroad. The existing point of view is to add steel wires, steel bars and steel materials inside the FRP material to form composite FRP bars. Product mixing ratio design is required, and industrial production methods and devices are lacking

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