Construction method for reinforcing T-beam through partially-bonded prestressed FRP

Abstract

The invention discloses a construction method for reinforcing a T-beam through partially-bonded prestressed FRP. The method includes the following steps that (1) prestressed FRP sheets are prepared through special equipment, namely the prestressed FRP sheets are prepared through an FRP quantitative-control self-anchored type prestress tensioning machine; (2) the prestressed FRP sheets are bonded to the T-beam to be reinforced, specifically, the prestressed FRP sheets prepared in the step (1) are bonded to matched positions of the bottom face of the T-beam to be reinforced through epoxy resin glue; and (3) the prestressed FRP sheets are anchored at least at the two ends and the midspan portion of the T-beam correspondingly through an anchoring device. According to the construction method, due to adoption of the specialized tools, the construction method has the characteristics that the construction method is simple, the construction speed is high and universality is high; the characteristic that multiple procedures can be conducted in parallel is achieved, and the T-beam reinforcing construction period can be shortened to the maximum extent; meanwhile, the wet-method construction range is small, the construction program is simplified, and high economic and social benefits are achieved.

Description

technical field [0001] The invention relates to a construction method, in particular to a construction method for strengthening T-beams by using partially bonded prestressed FRP, and belongs to the fields of buildings and bridges. Background technique [0002] Most of the old and old highway bridges in my country use T-beams as the main beam. Under the long-term action of vehicles, the main structure of the bridge (T-beam ribs) is damaged to varying degrees, which brings great hidden dangers to the safety of bridge structures. Therefore, it is of great practical significance to research and invent a T-beam strengthening construction method with superior performance and strong practicability. [0003] FRP sheets have been widely used in the field of bridge reinforcement, especially the use of prestressed FRP sheets, which overcomes the strain hysteresis of ordinary FRP materials and fully utilizes the high-strength properties of FRP materials. However, the core of its reinfo...

AI Technical Summary

Problems solved by technology

In the reinforcement construction using prestressed FRP sheets, the application of prestressed FRP sheets is generally not universal, and the applied prestress cannot be accurately controlled. Machines and tools are often anchored on the original structural beam as a counter force device. It can only be used once; the single-paste reinforcement method mainly strengthens the bending resistance of the main girder, and has no effect on the shear resistance of the T-beam; the pasting construction is easy to cause peeling and brittle failure of the FRP and concrete T-beam in the pasting layer, although it is also Many anchoring measures are used to prevent peeling damage, but these anchoring measures mostly use the same construction method of the same material, such as U-shaped FRP strips wound and pasted for anchoring; structure) to drill holes (destroy the main beam concrete, damage or cut off the steel bars in the beam) and then bury anchor devices to prevent stripping, which causes secondary damage to the already damaged beam ribs

In addition, the anchor structure itself is only used as a measure to prevent the peeling of the FRP material from the reinforced structure, and does not contribute to the reinforcement of the T-beam; in addition to the characteristics of long construction period and large temperature influence in large-area "wet" construction, FRP sheet The material has lost many of its original high-quality properties after being glued on a large area, but becomes more brittle and less ductile

Images