CN110438910B - Concrete structure reinforcing method with end embedded with prestressed FRP (fiber reinforced Plastic) strip - Google Patents
Concrete structure reinforcing method with end embedded with prestressed FRP (fiber reinforced Plastic) strip Download PDFInfo
- Publication number
- CN110438910B CN110438910B CN201910608577.3A CN201910608577A CN110438910B CN 110438910 B CN110438910 B CN 110438910B CN 201910608577 A CN201910608577 A CN 201910608577A CN 110438910 B CN110438910 B CN 110438910B
- Authority
- CN
- China
- Prior art keywords
- concrete structure
- frp
- grooves
- plank
- adhesive
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01D—CONSTRUCTION OF BRIDGES, ELEVATED ROADWAYS OR VIADUCTS; ASSEMBLY OF BRIDGES
- E01D22/00—Methods or apparatus for repairing or strengthening existing bridges ; Methods or apparatus for dismantling bridges
Landscapes
- Engineering & Computer Science (AREA)
- Architecture (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Reinforcement Elements For Buildings (AREA)
- Working Measures On Existing Buildindgs (AREA)
- Bridges Or Land Bridges (AREA)
Abstract
A concrete structure reinforcing method with end portions embedded with prestressed FRP (fiber reinforced Plastic) slabs comprises the following steps: the method comprises the following steps of firstly, slotting, wherein end slots with the same number are symmetrically arranged at two ends of a tension side of a concrete structure to be reinforced; mounting an FRP lath pressing device at the end part of the concrete structure; tensioning the FRP plank by using tensioning equipment, and applying prestress to the FRP plank; pressing two ends of the FRP lath into end grooves at two ends of the concrete structure respectively by using an FRP lath pressing device, and filling adhesives into the end grooves and the surfaces between the end grooves corresponding to the concrete structure; fourthly, after the binder is cured, putting tension prestress, and dismantling the FRP plank pressing device; the invention has good reinforcing effect, has small damage to the existing structure and obviously reduces the engineering cost.
Description
Technical Field
The invention relates to the technical field of reinforcement of concrete structures, in particular to a method for reinforcing a concrete structure with prestressed FRP (fiber reinforced Plastic) laths embedded at the ends.
Background
At present, over one million seats of railway and highway bridges are built in China, which are famous and reputable major bridges, wherein more than ninety percent of the bridges are concrete bridges. Due to the rapid increase of traffic volume and vehicle load, the problems of performance degradation and safety reduction of a service bridge are increasingly prominent, frequent bridge collapse events cause society to put forward higher requirements on service safety of the bridge, and a novel bridge reinforcing technology is urgently needed to be developed and applied.
Compared with the traditional reinforced concrete bridge structure reinforcing method, the bridge reinforcing technology based on the Fiber Reinforced Plastic (FRP) has many advantages: the FRP has high specific strength, and the mass of the reinforced structure is hardly increased; the corrosion resistance is good, and the structure can be reinforced in corrosive environments such as coastal environments; the reinforcing efficiency is high, and the binder can reach 80% of the designed strength in three days. The reinforcing technology based on FRP has been widely applied to the reinforcement of concrete structures, especially bridges, and achieves good effect. However, since FRP has a low elastic modulus compared to its strength, it is difficult to exert its high strength material property when reinforcing a reinforced concrete structure, and it is necessary to apply prestress to it. The currently available prestressed FRP reinforcement methods mainly comprise two modes of surface pasting and surface layer embedding. The method for reinforcing the FRP by sticking the prestressed FRP on the surface is convenient to construct, but the FRP is easy to peel and damage due to the single-sided bonding property of the FRP and the concrete structure, and the material performance of the FRP cannot be fully exerted; meanwhile, for materials with high tensile rigidity such as FRP plates and the like, the bond between FRP and concrete can not resist the prestress to realize the anchoring of FRP, so an FRP permanent anchorage device is often needed to inhibit the stripping damage and the anchoring prestress, and the cost is obviously increased. The surface layer embedded prestressed FRP is a structure reinforcing method which stretches FRP ribs or laths to apply prestress, then embeds the FRP ribs or laths into pre-grooves of a concrete protective layer, and uses a binder to bond the FRP ribs or laths and the concrete protective layer so as to cooperatively bear force. Compared with surface pasting, the surface layer embedding and pasting mode greatly expands the bonding area between the FRP and the concrete, and obviously improves the bonding capacity between the FRP and the concrete, thereby effectively inhibiting the stripping damage and realizing the anchoring of the prestress through the FRP-concrete bonding, and the cost is reduced without arranging an FRP permanent anchorage device. However, the reinforcing method needs to open the groove in the structural concrete protective layer, has high requirements on the accuracy of the groove, increases the construction workload for large-scale structures such as large-span bridges, and causes worry or worry about structural damage of related management departments due to the fact that the structure needs to be opened in a large range before reinforcement.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: the method overcomes the defects and provides a reinforcing method that the middle section of the prestressed FRP strip is pasted on the surface of the concrete structure, and the end part is embedded in the groove of the concrete structure.
The technical scheme adopted by the invention for solving the technical problem is as follows: a method for reinforcing a concrete structure with prestressed FRP (fiber reinforced Plastic) laths embedded at the ends comprises the following steps:
the method comprises the following steps of firstly, slotting, wherein end slots with the same number are symmetrically arranged at two ends of a tension side of a concrete structure to be reinforced;
mounting an FRP lath pressing device at the end part of the concrete structure;
tensioning the FRP plank by using tensioning equipment, and applying prestress to the FRP plank; pressing two ends of the FRP lath into end grooves at two ends of the concrete structure respectively by using an FRP lath pressing device, and filling adhesives into the end grooves and the surfaces between the end grooves corresponding to the concrete structure;
in the third step, firstly, the adhesive is filled in the end part grooves and the surfaces between the end part grooves corresponding to the concrete structure, then the FRP laths are stretched and placed, and then the adhesive is continuously filled in the end part grooves and the surfaces between the end part grooves corresponding to the concrete structure; or firstly tensioning and placing the FRP lath, and then filling the adhesive into the end grooves and the surface between the end grooves corresponding to the concrete structure;
fourthly, after the solidification of the binder is finished, the prestress is released, and the FRP plank pressing device is detached.
Preferably, in the step (i), an inclined transition groove is formed between the end groove and the surface of the end groove corresponding to the concrete structure, so that the groove bottom of the end groove is in uniform transition with the surface of the concrete structure.
Preferably, in the first step, after the end groove and the transition groove are formed, a high-pressure air gun is used for removing concrete dust in the end groove, the transition groove and the surface of the concrete structure, and then the concrete dust is cleaned by absolute ethyl alcohol.
Preferably, in the second step, the FRP plank pressing device comprises a first angle steel and a second angle steel which are symmetrically arranged on the side surface of the end part of the concrete structure, the vertical edge of the first angle steel is fixed on the side surface of the concrete structure through the transverse opposite penetrating screw rod, and the two ends of the horizontal edge of the first angle steel are respectively fixed with a vertical limiting screw rod; the horizontal edge of the second angle steel is sleeved at one end, far away from the first angle steel, of the vertical limiting screw, the vertical edge of the second angle steel is attached to the side surface of the concrete structure, through holes are formed in two ends of the second angle steel, and a steel roller shaft penetrating through the through holes is arranged between the second angle steels; and the two ends of the concrete structure are respectively provided with the FRP lath pressing devices.
Preferably, in the third step, two grooves are respectively formed at positions corresponding to the end grooves on the surface of the concrete structure; the second angle steel drives the steel roll shaft to move downwards in the groove on the vertical limiting screw rod, so that two ends of the FRP lath are pressed by the steel roll shaft to enter the end groove.
Preferably, in the third step, one of the grooves is arranged at the junction of the end groove and the transition groove, and the other groove is arranged at a position close to the end of the concrete structure.
Preferably, in the third step, the adhesive filled in the end grooves occupies 2/3 of the volume of the end grooves, and the thickness of the adhesive applied to the surface between the end grooves corresponding to the concrete structure is 2 mm.
Preferably, in the step (iv), the time for completing the curing of the binder is 7 days at normal temperature.
The invention has the beneficial effects that: the invention comprehensively utilizes the advantages of surface sticking FRP and surface layer embedding FRP, abandons the defects of the surface sticking FRP and the surface layer embedding FRP, can fully utilize the high-strength mechanical property of the reinforcing material by applying prestress on FRP, and has good reinforcing effect; the construction is simple and easy without the need of slotting along the whole length of the concrete structure, and the damage to the existing structure is small; the end part of the FRP lath is embedded in the groove, so that the stripping damage can be effectively inhibited; the adhesive in the end groove plays the role of an anchorage device, can anchor the prestress applied to the FRP, and obviously reduces the engineering cost.
Drawings
FIG. 1 is a schematic flow diagram of a consolidation method of the present invention;
FIG. 2 is a schematic three-dimensional representation of a specific example of the use of the method of the invention;
FIG. 3 is a three-dimensional representation of the end of a beam to be reinforced in a specific example using the method according to the invention;
FIG. 4 is a schematic front view of a specific embodiment of the method of the present invention;
FIG. 5 is a schematic top view of a specific embodiment of the process of the present invention;
FIG. 6 is a schematic side view of a specific embodiment of the method of the present invention.
1. Reinforcing the beam; 2. an end slot; 3. a transition groove; 4. FRP planks; 5. a first angle steel; 6. a second angle steel; 7. a steel roll shaft; 8. a transverse through screw; 9. a vertical limit screw; 10. and a nut.
Detailed Description
The invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.
As shown in fig. 1-6, the method for reinforcing a concrete structure based on end-embedded prestressed FRP slabs of the present invention comprises the steps of:
(1) grooving;
taking a concrete structure to be reinforced as the beam 1 to be reinforced as an example. A grooving machine is adopted to symmetrically arrange a plurality of end grooves 2 at preset positions of two ends of the tension side of a beam 1 to be reinforced along a central line, an inclined transition groove 3 is arranged between the end grooves 2 and the middle section of the beam 1 to be reinforced, a grinding machine is adopted to grind and flatten the bottom of the transition groove 3, and the distance, the length and the size of the end grooves 2 and the transition groove 3 are determined according to the size of the beam 1 to be reinforced, the rigidity of an FRP (fiber reinforced plastic) strip 4, the magnitude of applied prestress and related research specifications.
(2) Installing an FRP lath pressing device;
in this embodiment, the FRP plank pressing device is a tool for pressing the FRP plank 4 to which a prestress is applied into the end groove 2, and includes a first angle steel 5, a second angle steel 6, a steel roll shaft 7, a transverse opposite-penetrating screw 8, a vertical limiting screw 9, and a nut 10 thereon. Taking the beam 1 to be reinforced as an example, an electric hammer is adopted to punch a hole at a preset position on the side surface of the beam end to be reinforced, pre-holes are arranged on two sides of the first angle steel 5 and the second angle steel 6, a transverse through screw 8 is used for penetrating the beam 1 to be reinforced to fix one side of the first angle steel 5 on two sides of the beam 1 to be reinforced (when the beam section width is larger, a chemical bolt is preferably adopted to replace the transverse through screw), one end of a vertical limiting screw 9 is fixed at the pre-hole on the other side of the first angle steel 5, and the other end of the vertical limiting screw is sleeved in the second angle steel 6. The FRP lath pressing devices are respectively arranged at the two ends of the beam 1 to be reinforced.
(3) Filling an adhesive;
cleaning the surface of the beam 1 to be reinforced on the tension side and dust particles in the groove by using a high-pressure air gun and a steel fiber brush, cleaning the surface of the beam 1 to be reinforced on the tension side and the inner surface of the groove by using a volatile harmless solution such as acetone or alcohol, drying, filling two thirds of the volume of the binder into the groove, and smearing the binder with the thickness of about 2mm on the surface of the beam on the tension side.
(4) Tensioning the FRP plank 4, and pressing two ends of the FRP plank 4 into the grooves;
the dimension of the FRP lath is reasonably selected according to related research specifications and the magnitude of the prestress applied by design, and a related tensioning device is used for clinging to the tension side surface of the beam 1 to be reinforced to accurately apply the designed prestress value to the FRP lath 4.
Two grooves are respectively arranged at the positions of the surface of the concrete structure corresponding to the end grooves 2, wherein one groove is arranged at the junction of the end groove and the transition groove, and the other groove is arranged at the position close to the end of the concrete structure. Insert steel roller 7 in the trompil in advance of second angle steel 6, twist nut 10 on the vertical stop screw of moving makes second angle steel 6 down, thereby it is down in the recess to drive steel roller 7, so that 4 both ends of FRP lath receive steel roller 7 oppression entering groove, this in-process should guarantee that steel roller 7 of 6 each departments of second angle steel pushes down simultaneously, it is suitable that the clearance equals about pushing down the terminal point with FRP lath 4, FRP lath 4 is pressed to the inslot intussuseption binder and floating surface when reaching the assigned position.
(5) Curing the binder;
the special FRP reinforcing binder is cured at normal temperature according to the requirements of related products, the specified strength is achieved within 7 days, the curing time at high temperature can be properly shortened, the necessary constant-temperature curing is adopted at low temperature, and the curing time is properly prolonged.
(6) Releasing the paper;
and after the adhesive is cured to reach the strength, releasing the prestress generated by the tensioning equipment on the FRP plank, removing the FRP plank pressing device, carefully knocking out the steel roller shaft 7 and filling the adhesive in the gap.
The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above-mentioned embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may be made by those skilled in the art without departing from the principle of the invention.
Claims (8)
1. A concrete structure reinforcing method with end portions embedded with prestressed FRP (fiber reinforced Plastic) slabs is characterized by comprising the following steps:
the method comprises the following steps of firstly, slotting, wherein end slots with the same number are symmetrically arranged at two ends of a tension side of a concrete structure to be reinforced;
mounting an FRP lath pressing device at the end part of the concrete structure;
tensioning the FRP plank by using tensioning equipment, and applying prestress to the FRP plank; pressing two ends of the FRP lath into end grooves at two ends of the concrete structure respectively by using an FRP lath pressing device, filling a bonding agent into the end grooves and smearing the bonding agent on the surface between the corresponding end grooves of the concrete structure;
filling the end grooves with the adhesive and smearing the adhesive on the surface between the end grooves corresponding to the concrete structure, tensioning the FRP plank, pressing the two ends of the FRP plank into the end grooves, filling the end grooves with the adhesive and continuously smearing the adhesive on the surface between the end grooves corresponding to the concrete structure; or tensioning the FRP plank, pressing the two ends of the FRP plank into the end grooves, filling the end grooves with the adhesive and smearing the adhesive on the surface between the end grooves corresponding to the concrete structure;
fourthly, after the solidification of the binder is finished, the prestress is released, and the FRP plank pressing device is detached.
2. The method for reinforcing a concrete structure with prestressed FRP slat embedded at the ends as claimed in claim 1, wherein in step (r), inclined transition grooves are formed between the end grooves and the surface of the corresponding end groove of the concrete structure, so that the bottom of the end groove is uniformly transited to the surface of the concrete structure.
3. The method for reinforcing a concrete structure with prestressed FRP slat embedded at the ends as claimed in claim 2, wherein in the step (r), after the end grooves and the transition grooves are opened, concrete dust in the end grooves, the transition grooves and the surface of the concrete structure is removed by using a high pressure air gun, and then the concrete structure is cleaned by using absolute ethyl alcohol.
4. The method for reinforcing a concrete structure with prestressed FRP slabs embedded at the ends as claimed in claim 1, wherein in step (II), the FRP slab pressing means comprises a first angle steel and a second angle steel which are symmetrically arranged at the side of the concrete structure end, the vertical edge of the first angle steel is fixed at the side of the concrete structure by a transverse penetrating screw, and the two ends of the horizontal edge of the first angle steel are respectively fixed with a vertical limit screw; the horizontal edge of the second angle steel is sleeved at one end, far away from the first angle steel, of the vertical limiting screw, the vertical edge of the second angle steel is attached to the side surface of the concrete structure, through holes are formed in two ends of the second angle steel, and a steel roller shaft penetrating through the through holes is arranged between the second angle steels; and the two ends of the concrete structure are respectively provided with the FRP lath pressing devices.
5. The method for reinforcing a concrete structure with prestressed FRP slabs embedded at the ends as claimed in claim 4, wherein in step (iii), two grooves are respectively formed at the positions corresponding to the end grooves on the surface of the concrete structure; the second angle steel drives the steel roll shaft to move downwards in the groove on the vertical limiting screw rod, so that two ends of the FRP lath are pressed by the steel roll shaft to enter the end groove.
6. The method for reinforcing a concrete structure with prestressed FRP slat embedded at its ends as claimed in claim 5, wherein in step (iii), one of the grooves is provided at the boundary of the end groove and the transition groove, and the other groove is provided at a position near the end of the concrete structure.
7. The method for reinforcing a concrete structure with prestressed FRP panels fitted at the ends thereof as claimed in claim 1, wherein said step (iii) is carried out by filling 2/3 the volume of the end grooves with the adhesive before filling the adhesive, and the thickness of the adhesive applied to the surface between the corresponding end grooves of the concrete structure is 2 mm.
8. The method for reinforcing a concrete structure with prestressed FRP panels fitted at the ends thereof as claimed in claim 1, wherein in said step (iv), the time for completion of curing of said adhesive is 7 days at ordinary temperature.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910608577.3A CN110438910B (en) | 2019-07-08 | 2019-07-08 | Concrete structure reinforcing method with end embedded with prestressed FRP (fiber reinforced Plastic) strip |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910608577.3A CN110438910B (en) | 2019-07-08 | 2019-07-08 | Concrete structure reinforcing method with end embedded with prestressed FRP (fiber reinforced Plastic) strip |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110438910A CN110438910A (en) | 2019-11-12 |
| CN110438910B true CN110438910B (en) | 2021-01-05 |
Family
ID=68429568
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910608577.3A Active CN110438910B (en) | 2019-07-08 | 2019-07-08 | Concrete structure reinforcing method with end embedded with prestressed FRP (fiber reinforced Plastic) strip |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110438910B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111535206A (en) * | 2020-05-14 | 2020-08-14 | 长沙理工大学 | Construction method and construction system for FRP reinforcement |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100653632B1 (en) * | 2006-01-18 | 2006-12-05 | 한국건설기술연구원 | Strengthening method for concrete structures with prestressed near surface mounted fiber reinforced polymer composites |
| CN102425311B (en) * | 2011-09-05 | 2015-02-25 | 长沙理工大学 | Concrete structure reinforcing method based on near surface mounted prestressed FRP (Fiber Reinforced Polymer) |
| CN105569372B (en) * | 2016-02-04 | 2017-05-03 | 广东工业大学 | Device and method for enhancing composite reinforced concrete through prestress fiber |
| CN105952180A (en) * | 2016-05-31 | 2016-09-21 | 广东工业大学 | Method for reinforcing concrete structure through embedded wet and sticky FRP strips and component of method |
-
2019
- 2019-07-08 CN CN201910608577.3A patent/CN110438910B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN110438910A (en) | 2019-11-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105625197A (en) | Concrete beam bending reinforcing method based on steel plate-prestressed carbon fiber plate | |
| CN102425311A (en) | Concrete structure reinforcing method based on near surface mounted prestressed FRP (Fiber Reinforced Polymer) | |
| CN103485546A (en) | Prestress tension device and tension method for carbon fiber sheets | |
| CN204715227U (en) | Case beam ruggedized construction | |
| CN110438910B (en) | Concrete structure reinforcing method with end embedded with prestressed FRP (fiber reinforced Plastic) strip | |
| CN102409767A (en) | Waterproof leaking stoppage structure of building seam and construction method | |
| CN110607920B (en) | A stretch-draw anchor that is used for top layer to inlay prestressing force FRP lath | |
| CN107268459B (en) | Construction method for prestressed fiber cloth reinforced concrete pier column | |
| CN103837383B (en) | Pre-stressed carbon fiber sheet material dual-flat plate ground tackle anchoring property test method | |
| CN111733891A (en) | Reinforcing and corrosion preventing method for underwater structure | |
| CN110593600A (en) | Beam-slab reinforcing structure of existing building and construction method | |
| CN107059663A (en) | A kind of device of utilization pre-stress FRP cloth reinforced steel concrete pier stud | |
| CN202265908U (en) | Waterproof and leaking-stoppage structure for construction joint | |
| CN202299472U (en) | Reinforcing structure for reinforcing concrete beam by pre-stressed carbon fibre plate | |
| CN104278632A (en) | Bridge main tower creeping formwork and manufacturing method thereof | |
| CN106703288B (en) | Method for manufacturing carbon fiber grid composite plate concrete continuous beam | |
| CN112360179A (en) | Construction method for reinforcing reinforced concrete beam by prestressed FRP (fiber reinforced Plastic) sheet | |
| CN110748185A (en) | In-situ bar planting pouring and reinforcing method for partially rotten ancient building wood beam | |
| CN202787050U (en) | Novel prestress carbon fiber sheet anchor device | |
| CN103866990A (en) | Method for reinforcing shear wall by using X-shaped basalt fiber cloth | |
| CN110820603B (en) | Bridge vertical prestress loss compensation method based on surface layer embedded prestress lath | |
| CN211114954U (en) | Beam slab reinforcing structure of existing building | |
| WO2021142990A1 (en) | Imprinting material, and roughening construction method for new and old concrete joint surface | |
| CN110644382A (en) | Variable cross-section beam prestressed carbon fiber plate multi-point anchoring segmented reinforcing construction method | |
| CN203782980U (en) | Double-flat-plate type anchorage device for prestressed carbon fiber sheets |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |