A method for prestressed beam and slab reinforcement and a beam and slab reinforcement auxiliary device

Abstract

The application discloses a prestressed reinforced beam plate method and a beam plate reinforcing auxiliary device. The method is to fix the reinforced plate with FRP tendon in tension prestressed state on the tension side of the beam plate to be reinforced. The auxiliary device comprises a steel carrier, two anchorage devices, two clamps, a component and an FRP tendon. The component is arranged above the carrier. The two anchorage devices are fixed at the two ends of the carrier in the length direction. The two clamps are respectively fixed on the back surfaces of the two anchorage devices. A length direction extending slot is arranged on the side of the component away from the carrier. The slot is filled with adhesive. The FRP tendon is arranged in the slot and fixed with the component through the adhesive. The two ends of the FRP tendon pass through the anchorage devices and are fixed by the clamps to keep the FRP tendon in the tension prestressed state. The method has the advantages of improving the reinforcing effect of the beam plate.

Description

Technical Field

[0001] The present invention relates to the field of beam reinforcement, and in particular to a method for prestressed beam and slab reinforcement and a beam and slab reinforcement auxiliary device. Background Art

[0002] In order to improve the failure mode of this type of structural bending members and enhance the bearing capacity of beams and slabs under normal use loads and accidental loads, researchers have successively proposed different reinforcement technologies and carried out experimental and theoretical research. Existing technologies for strengthening beams and slabs mainly include reinforcement with steel mesh modified mortar, surface embedded CFRP bars, and external prestressed reinforcement. The technology for strengthening beams with prefabricated CFRP bar reinforced plates is to form a reinforcement plate by embedding CFRP bars (without prestressing) in the surface of the prefabricated member (the member, reinforcement plate and the reinforced beam plate are made of the same material), and then affix the reinforcement plate to the tensile bottom surface of the beam to achieve bending reinforcement. However, the existing technology for strengthening beams with CFRP bar reinforced plates is still not ideal, its reinforcement strength needs to be further improved, and its reinforcement effect still has room for improvement. Summary of the Invention

[0003] The present invention provides a method for prestressed reinforcement of beams and slabs and a beam and slab reinforcement auxiliary device, which overcome the deficiencies of the prior art described in the background art.

[0004] The technical solution adopted by the present invention to solve its technical problem is:

[0005] A method for prestressing a beam and slab is to fix a reinforcing plate with FRP bars in a tensioned prestressed state on the tension side of the beam and slab to be reinforced.

[0006] In one embodiment, the FRP reinforcement is a CFRP reinforcement.

[0007] In one embodiment, the following steps are included:

[0008] Step 1: Slot the component surface along the length direction according to the design specifications, with the width and depth of the slot matching the diameter of the FRP reinforcement;

[0009] Step 2: Blow away the dust remaining on the groove and component surface and rinse with water;

[0010] Step 3: After the surface of the component is dry, inject adhesive into the slot;

[0011] Step 4: Place the FRP bar into the groove until the adhesive completely covers the FRP bar.

[0012] Step 5: tensioning the FRP bars along the length direction to allow the FRP bars to store elastic potential energy and form a prestressed reinforced plate;

[0013] Step 6: Paste the reinforcing plate with embedded reinforcement on the surface of the tensile area of ​​the beam and slab to be reinforced, and let it stand until the adhesive solidifies.

[0014] In one embodiment, the width and depth of the notch section are both twice the diameter of the FRP bar.

[0015] A prestressed beam and slab reinforcement auxiliary device includes a steel carrier, two anchors, two clamps, a component and an FRP bar. The component is placed above the carrier, the two anchors are fixed at both ends of the carrier in the length direction, and the two clamps are respectively fixed on the back surfaces of the two anchors. A groove extending along the length direction is opened on the side surface of the component facing away from the carrier, and the groove is filled with adhesive. The FRP bar is placed in the groove and fixed to the component by the adhesive. The two ends of the FRP bar pass through the anchors and are fixed by the clamps so that the FPR bar remains in a prestressed tensioned state.

[0016] In one embodiment, the FRP reinforcement is a CFRP reinforcement.

[0017] In one embodiment, the width and depth of the slot are both twice the diameter of the FRP bar.

[0018] In one embodiment, the clamp and the anchor are fixed by bolts and nuts.

[0019] In one embodiment, the anchor is fixed to the carrier by welding.

[0020] In one embodiment, the carrier is an I-beam.

[0021] Compared with the background technology, this technical solution has the following advantages:

[0022] 1. Fix the reinforcement plate with FRP tendons in a prestressed state on the tensile side of the beam to be reinforced, so that the FRP tendons in a prestressed state transfer the prestressing force to the beam through the reinforcement plate. After the beam receives the prestressing force of the FRP tendons, it is relatively in a tightened state, so that the beam can bear a greater load and improve the deformation resistance of the beam.

[0023] 2. The prestressed beam and slab reinforcement auxiliary device described in this case can keep the FRP tendons in a tensioned prestressed state before the reinforcement plate is fixed to the beam and slab, thereby assisting the reinforcement operation of the beam and slab with the reinforcement plate having prestressed FRP tendons. The prestressed beam and slab reinforcement auxiliary device can realize batch production in the factory, improve the production efficiency of the prestressed reinforcement plate, and further improve the on-site reinforcement operation efficiency of the beam and slab. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be further described below with reference to the accompanying drawings and examples.

[0025] Figure 1This is a schematic diagram of the three-dimensional structure of the prestressed beam and slab reinforcement auxiliary device.

[0026] Figure 2 This is the main view of the anchor.

[0027] Figure 3 A side view of the anchor.

[0028] Figure 4 A top view of the anchor.

[0029] Figure 5 This is the main view of the fixture.

[0030] Figure 6 A side view of the fixture.

[0031] Figure 7 A top view of the fixture.

[0032] Figure 8 A cross-sectional view of the carrier. DETAILED DESCRIPTION

[0033] Please refer to Figures 1 to 8 A prestressed beam and slab reinforcement auxiliary device includes a steel carrier 1, two anchors 2, two clamps 3, a component 4, and an FRP bar 5. The component 4 is placed above the carrier 1, the two anchors 2 are fixed at both ends of the carrier 1 in the length direction, and the two clamps 3 are respectively fixed on the back surfaces of the two anchors 2. A slot 41 extending along the length direction is provided on the side of the component 4 facing away from the carrier 1. The slot 41 is filled with an adhesive. The FRP bar 5 is placed in the slot 41 and fixed to the component 4 by the adhesive. The two ends of the FRP bar 5 pass through the anchor 2 and are fixed by the clamp 3 so that the FRP bar 5 maintains a prestressed tension state. Typically, the anchor 2 has a groove, and the clamp 3 is a grooved clamp. The two ends of the FRP bar 5 pass through the groove on the anchor 2 and fall into the groove of the clamp 3 for fixation.

[0034] In this embodiment, the FRP bar 5 is a CFRP bar. The slot 41 has a cross-sectional width and depth that is twice the diameter of the FRP bar. The clamp 3 is secured to the anchor 2 via bolts and nuts. The anchor 2 is welded to the carrier 1. The carrier 1 is an I-beam.

[0035] The specific manufacturing process of the prestressed beam and slab reinforcement auxiliary device includes the following steps:

[0036] Step 11: stably place the component on the carrier, fix two anchors 2 at both ends of the carrier 1 in the length direction, and fix two clamps 3 on the back surfaces of the two anchors 2 respectively;

[0037] Step 12: according to the design specifications, a groove 41 is formed on the surface of the component 4 along the longitudinal direction, and the width and depth of the groove section match the diameter of the FRP bar 5; usually, the width and depth of the groove section are twice the diameter of the FRP bar 5;

[0038] Step 13: Blow away the dust remaining on the surface of the slot 41 and the component 4 and rinse with water;

[0039] Step 14: After the surface of the component 4 is dry, an adhesive is injected into the groove 41 to form an adhesive layer. The adhesive is injected to a depth of about 1 / 2 of the groove.

[0040] Step 15: Place the FRP bar 5 into the groove until the adhesive completely covers the FRP bar 5 and both ends of the FRP bar 5 pass through the anchor 2 and fall on the clamp 3;

[0041] In step 15, the FRP tendons 5 are tensioned along the length direction to store elastic potential energy, and the FRP tendons 5 are fixed by the clamp 3 to keep the FRP tendons 5 tensioned and loaded. At this time, the component 4 and the FRP tendons 5 in the component 4 form a reinforced plate with prestress. At this point, the production of the prestressed beam and slab reinforcement auxiliary device is completed.

[0042] A method for prestressing a beam and slab is to fix a reinforcement plate with prestressed FRP (Fiber Reinforced Plastics) bars 5 on the tension side of the beam and slab to be reinforced. The FRP bars 5 are CFRP (Carbon Fiber Reinforced Plastics) bars.

[0043] The method for prestressing beam-slab reinforcement comprises the following specific steps:

[0044] Step 1: according to the design specifications, a groove 41 is formed on the surface of the component 4 along the longitudinal direction, and the width and depth of the groove section match the diameter of the FRP bar 5; usually, the width and depth of the groove section are twice the diameter of the FRP bar 5;

[0045] Step 2: Blow away the dust remaining on the surface of the slot 41 and the component 4 and rinse with water;

[0046] Step 3: After the surface of the component 4 is dry, inject adhesive into the groove 41 to a depth of about 1 / 2 of the groove;

[0047] Step 4: Place the FRP bar 5 into the groove until the adhesive completely covers the FRP bar 5;

[0048] Step 5: tensioning the FRP tendons 5 along the length direction, so that the FRP tendons 5 store elastic potential energy, and the component and the FRP tendons in the component form a reinforced plate with prestress;

[0049] Step 6: Paste the reinforcing plate with embedded reinforcement on the surface of the tensile area of ​​the beam and slab to be reinforced, and let it stand until the adhesive solidifies.

[0050] The prestressed beam and slab reinforcement auxiliary device described in this case can keep the FRP tendons 5 in a tensioned prestressed state before the reinforcement plate is fixed to the beam and slab, thereby assisting the reinforcement operation of the beam and slab by the reinforcement plate with prestressed FRP tendons 5. The prestressed beam and slab reinforcement auxiliary device can be mass-produced in the factory, and steps 1 to 5 in the method of reinforcing the beam and slab can be completed in the factory through the auxiliary device. When it is necessary to reinforce the beam and slab by prestressing, the prestressed beam and slab reinforcement auxiliary device manufactured in the factory is brought to the site, the reinforcing plate with embedded reinforcement on one side is coated with adhesive, and then it is attached to the surface of the tensile area of ​​the beam to be reinforced and left to stand until the adhesive solidifies. After that, the anchor 5, clamp 3 and carrier 1 are removed, completing the process of transferring the prestress from the reinforcing plate to the reinforced beam (the specific force transfer process is: the tensile stress on the FRP bar 5 is transferred to the component 4, and then the component 4 is transferred to the beam and slab, so that the beam and slab form a prestressed inward contraction corresponding to the tensile stress). This makes the reinforcing plate have a better reinforcement effect on the beam, can withstand greater loads, and improve deformation resistance. In this device, the anchor 2, clamp 3 and carrier 1 are all designed to complete the tensioning of the FRP bar 5 and maintain the predetermined prestress level, thereby completing the production of the prestressed reinforced plate.

[0051] The above description is merely a preferred embodiment of the present invention and therefore cannot be used to limit the scope of the present invention. In other words, equivalent changes and modifications made according to the scope of the present invention and the contents of the specification should still fall within the scope of the present invention.

Claims

1. A method for prestressed reinforcement of beams and slabs, characterized by: A reinforcement plate with FRP bars in a prestressed state is fixed on the tension side of the beam to be reinforced; the FRP bars are CFRP bars; the steps include: Step 1: Slot the component surface along the length direction according to the design specifications, with the width and depth of the slot matching the diameter of the FRP reinforcement; Step 2: Blow away the dust remaining on the groove and component surface and rinse with water; Step 3: After the surface of the component is dry, inject adhesive into the slot; Step 4: Place the FRP bar into the groove until the adhesive completely covers the FRP bar. Step 5: tensioning the FRP bars along the length direction to allow the FRP bars to store elastic potential energy and form a prestressed reinforced plate; Step 6: Paste the reinforcing plate with one side of the embedded reinforcement to the tensile area of ​​the beam and slab to be reinforced, and let it stand until the adhesive solidifies; The width and depth of the notch section are both twice the diameter of the FRP bar; The above-mentioned method of prestressed reinforcement of beams and slabs adopts a prestressed beam and slab reinforcement auxiliary device, including a steel carrier, two anchors, two clamps, a component and an FRP bar. The component is placed above the carrier, the two anchors are fixed at both ends of the carrier in the length direction, and the two clamps are respectively fixed on the back surfaces of the two anchors. A groove extending along the length direction is opened on the side surface of the component facing away from the carrier, and the groove is filled with adhesive. The FRP bar is placed in the groove and fixed to the component by the adhesive. The two ends of the FRP bar pass through the anchors and are fixed by the clamps so that the FPR bar remains in a prestressed tensioned state.

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