CN114809704B - Tightening type external prestress CFRP material reinforcing system and construction method - Google Patents
Tightening type external prestress CFRP material reinforcing system and construction method Download PDFInfo
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- CN114809704B CN114809704B CN202210568472.1A CN202210568472A CN114809704B CN 114809704 B CN114809704 B CN 114809704B CN 202210568472 A CN202210568472 A CN 202210568472A CN 114809704 B CN114809704 B CN 114809704B
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- 239000004918 carbon fiber reinforced polymer Substances 0.000 title claims abstract description 133
- 238000010276 construction Methods 0.000 title claims abstract description 41
- 239000000463 material Substances 0.000 title claims abstract description 28
- 230000003014 reinforcing effect Effects 0.000 title claims abstract description 20
- 230000002787 reinforcement Effects 0.000 claims abstract description 81
- 230000007246 mechanism Effects 0.000 claims abstract description 78
- 238000000034 method Methods 0.000 claims abstract description 23
- 238000007906 compression Methods 0.000 claims abstract description 14
- 230000006835 compression Effects 0.000 claims abstract description 13
- 230000000670 limiting effect Effects 0.000 claims description 8
- 239000002131 composite material Substances 0.000 claims description 5
- 239000000853 adhesive Substances 0.000 claims description 4
- 230000001070 adhesive effect Effects 0.000 claims description 4
- 238000004873 anchoring Methods 0.000 claims description 4
- 239000002184 metal Substances 0.000 claims description 4
- 238000005520 cutting process Methods 0.000 claims description 3
- 238000003825 pressing Methods 0.000 claims description 3
- 238000000338 in vitro Methods 0.000 claims 5
- 230000008569 process Effects 0.000 abstract description 14
- 230000000694 effects Effects 0.000 abstract description 7
- 230000002829 reductive effect Effects 0.000 abstract description 6
- 230000035882 stress Effects 0.000 description 14
- 239000012779 reinforcing material Substances 0.000 description 8
- 230000009471 action Effects 0.000 description 5
- 238000005452 bending Methods 0.000 description 5
- 230000008859 change Effects 0.000 description 5
- 230000036961 partial effect Effects 0.000 description 3
- 230000001360 synchronised effect Effects 0.000 description 3
- 229920000049 Carbon (fiber) Polymers 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 239000004917 carbon fiber Substances 0.000 description 2
- 238000013329 compounding Methods 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- 230000002401 inhibitory effect Effects 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
- 229920006231 aramid fiber Polymers 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
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- 238000004643 material aging Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
- 239000002023 wood Substances 0.000 description 1
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- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
- E04G23/00—Working measures on existing buildings
- E04G23/02—Repairing, e.g. filling cracks; Restoring; Altering; Enlarging
- E04G23/0218—Increasing or restoring the load-bearing capacity of building construction elements
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- 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
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- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
- E04G23/00—Working measures on existing buildings
- E04G23/02—Repairing, e.g. filling cracks; Restoring; Altering; Enlarging
- E04G23/0218—Increasing or restoring the load-bearing capacity of building construction elements
- E04G2023/0251—Increasing or restoring the load-bearing capacity of building construction elements by using fiber reinforced plastic elements
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Abstract
The invention discloses a tightening type external prestress CFRP material reinforcing system and a construction method, wherein the tightening type external prestress CFRP material reinforcing system comprises a structural member to be reinforced and a CFRP reinforcing member, two ends of the CFRP reinforcing member are respectively connected with the structural member to be reinforced through end fixing mechanisms, at least one supporting mechanism is arranged on the structural member to be reinforced and comprises a base, a tightening screw is erected on the base, a compression nut and a steering block are arranged on the tightening screw, the CFRP reinforcing member is positioned between the steering block and the base, a prestress adjusting mechanism is detachably arranged on the base and used for adjusting the height of the steering block on the tightening screw. The effect is as follows: according to the invention, only one section of CFRP reinforcement is utilized to realize external prestress reinforcement, so that only a fixing mechanism is arranged at the end part of one section of CFRP reinforcement, the number of anchors required by construction is greatly reduced, the process of tensioning the CFRP reinforcement is simplified, the construction cost is reduced, and the construction efficiency is improved.
Description
Technical Field
The invention relates to the technical field of external prestressing force application in civil engineering, in particular to a tightening type external prestressing force CFRP material reinforcing system and a construction method.
Background
The concrete structural member or the steel structural member in engineering structures of modern buildings, traffic, bridges and the like has huge potential safety hazards due to the conditions of insufficient bearing capacity or cracking and the like caused by environmental corrosion, material aging, change of structural functions and the like or natural disasters.
The existing reinforcement methods for engineering components are divided into two major categories from the principle of action, namely a passive reinforcement method and an active reinforcement method. Passive reinforcement refers to directly adding tensile (or shear) reinforcing materials in the tensile (or shear) weak area of a member, for example: and (3) sticking a steel plate, sticking a high-strength fiber composite material (carbon fiber and aramid fiber) and the like. The reinforcing material only bears the internal force caused by the live load and the post-load, and compared with the original stressed member, the strain (stress) of the reinforcing material is relatively lagged. In particular, the scheme of directly sticking high-strength fiber composite materials is adopted, so that the high tensile property of the reinforcing material is difficult to play a role. Therefore, the passive reinforcement method cannot reduce the deformation of the original structure and cannot close the crack. Active reinforcement refers to the application of a pre-stress to a reinforcing material disposed in a region of tension (or shear) weakness of a member. The reinforcing material is actively stressed, so that the problem of strain (stress) hysteresis of the post-reinforcing material is fundamentally solved, the high tensile property of the reinforcing material can be fully exerted, the utilization efficiency of the material is improved, and the bending-resistant bearing capacity and the normal working performance of the reinforced member are both obviously improved.
Chinese patent No. ZL201711297399.4 discloses a CFRP plate multipoint support prestress reinforcement structure assembly and a prestress application method thereof, the structure assembly comprising: the structural member is a metal structural member suitable for bearing load; the CFRP plate is arranged on the structural member and is provided with at least two connecting points connected to the structural member; the supporting device is arranged on the structural member and located between the two connecting points, the supporting device comprises an adjusting screw and a supporting piece, the adjusting screw is rotatably arranged on the structural member, the supporting piece is in threaded fit with the adjusting screw, the distance between the supporting piece and the structural member is adjustable when the adjusting screw rotates, the supporting piece is supported on the CFRP plate, and the supporting piece can jack up the CFRP plate to deform towards a direction away from the structural member when the distance between the supporting piece and the structural member is increased.
However, the above-described structural assembly has the following drawbacks during the prestressing:
(1) The screw belongs to an elongated member, the screw is easy to be pressed and unstably pressed in the jacking process, and the construction is dangerous;
(2) When the multipoint support is formed, a plurality of screws are required to lift up simultaneously, the synchronous lifting uniformity is difficult to ensure by manual operation, and the carbon fiber plate is easy to be stressed unevenly;
(3) The screw jacking force is very limited, large tonnage cannot be realized, and engineering application scenes are limited;
(4) The end part adopts a flat plate clamping mode, so that the anchoring efficiency is low, and the prestress loss is larger;
(5) The support rod is screwed by bolts, so that the prestress loss is large, and the construction is difficult;
(6) The lack of steering measures at the end portions can easily bend or twist the CFRP plate, so that the CFRP plate is damaged or even broken.
In view of this, chinese patent No. ZL201911310457.1 discloses a reinforced mounting system of a combined beam string of CFRP sheet, which comprises a beam body, n+1 CFRP sheets, n fixing brackets and 2n+2 anchors, n is a positive integer greater than or equal to 1, the beam body is horizontally arranged, the fixing brackets are arranged on the lower surface of the beam body, two anchors are hinged to the lower ends of the fixing brackets, two hinge seats are further arranged at two ends of the lower surface of the beam body, the fixing brackets are positioned between the two hinge seats, two hinge seats are respectively hinged with one anchor, a CFRP sheet is arranged between each hinge seat and the adjacent fixing bracket, a CFRP sheet is also arranged between the adjacent two fixing brackets, and two ends of the CFRP sheet are clamped on the corresponding anchors. According to the CFRP sheet stretching device, the vertical load is dispersed through the support, so that the local stress of a structural part is relieved, the stress is relatively dispersed in the CFRP sheet stretching process by utilizing the hinge seat, the CFRP sheet is prevented from being sheared and damaged, and the CFRP sheet is guaranteed to be uniformly stressed.
However, the CFRP sheet in the above system adopts a segmented anchoring method, and the following problems still exist in construction:
(1) The CFRP sheet is divided into a plurality of sections, each section needs 2 anchors, and the number of the anchors is large, the operation is complex and the cost is high;
(2) The CFRP sheets are arranged in a segmented mode, prestress tensioning is needed to be carried out on each segment, construction steps are multiple and complex, and prestress is difficult to keep consistent;
(3) By adopting sectional type, each section has prestress loss, and the nodes are not regulated;
(4) If CFRP sheet prestress tensioning of adjacent segments is not synchronous, unbalanced force is generated on the fixing bracket, and adverse effects may be caused. If synchronous tensioning is adopted, all the segments need to be synchronously tensioned, so that the construction is difficult and the application is difficult.
Disclosure of Invention
The invention aims to provide a tightening type external prestress CFRP material reinforcing system, which only adopts a section of continuous CFRP reinforcing member to realize reinforcement, so that a fixing mechanism is only required to be arranged at the end part of the section of CFRP reinforcing member, and only a section of CFRP reinforcing member is required to be tensioned when prestress is applied, thereby greatly reducing the number of anchorage devices required by construction, reducing the tensioning difficulty and being beneficial to improving the construction efficiency; the invention also aims at a construction method based on the tightening type external prestress CFRP material reinforcing system.
In order to achieve the above purpose, the invention firstly provides a tightening type external prestress CFRP material reinforcement system, which comprises a structural member to be reinforced and a CFRP reinforcement, and is characterized in that two ends of the CFRP reinforcement are respectively connected with the structural member to be reinforced through end fixing mechanisms, at least one supporting mechanism is arranged on the structural member to be reinforced, the supporting mechanism comprises a base, a tightening screw is erected on the base, a compression nut and a steering block are arranged on the tightening screw, the CFRP reinforcement is positioned between the steering block and the base, and a prestress adjusting mechanism is also detachably arranged on the base and is used for adjusting the height of the steering block on the tightening screw.
Still further, prestressing force adjustment mechanism includes counter-force board and jack, the counter-force board detachably install in tighten up the upper end of screw rod, the jack butt in between the counter-force board with turn to the piece.
Furthermore, a limiting plate is arranged on the jack, and a through hole for inserting the tightening screw rod is reserved in the limiting plate.
Still further, the supporting mechanism also comprises at least two supporting rods, the upper ends of the supporting rods are fixed on the structural member to be reinforced through connecting plates, and the lower ends of the supporting rods are connected with the base.
Still further, tip fixed establishment includes anchor, connecting piece and ground tackle, the connecting piece with connect through first direction pivot between the anchor, the connecting piece with hinge through the second direction pivot between the ground tackle, the axis of first direction pivot with the axis quadrature of second direction pivot.
Still further, the CFRP reinforcement is one or a combination of more of CFRP plates, CFRP cables or CFRP grids, and the anchor is any one of a flat plate anchor, a wedge anchor or a wave anchor.
Further, the CFRP reinforcement is formed by overlapping a plurality of CFRP plates, and the anchor is correspondingly provided with anchor interfaces of the CFRP plates.
Based on the structure described above, the invention also provides a construction method, which is characterized by comprising the following steps:
s1: two ends of the CFRP reinforcement are respectively arranged on the structural member to be reinforced through end fixing mechanisms;
s2: a supporting mechanism is arranged between the two end fixing mechanisms at a preset interval;
s3: a tightening screw is arranged on a base of the supporting mechanism, and a steering block and a compression nut are sequentially arranged on the tightening screw, so that the CFRP reinforcement is positioned between the steering block and the base;
s4: the prestress adjusting mechanism is arranged on the base, and the height of the steering block is adjusted through the prestress adjusting mechanism;
s5: the steering block is pressed tightly through the pressing nut;
s6: dismantling the prestress adjusting mechanism;
s7: and cutting off redundant tightening screws above the compression nuts.
Further, before the turning block is pressed in step S5, an adhesive is applied between the CFRP reinforcement and the turning block.
Further, the structural member to be reinforced is any one of a metal structural member, a concrete structural member, a wood structural member or a combined structural member.
Compared with the prior art, the invention has the remarkable effects that:
1. according to the invention, only one section of CFRP reinforcement is utilized to realize external prestress reinforcement, so that only a fixing mechanism is arranged at the end part of one section of CFRP reinforcement, the number of anchorage devices required by construction is greatly reduced, the process of tensioning the CFRP reinforcement is simplified, the construction cost is reduced, and the construction efficiency is improved;
2. in the prestress application process, the steering block can limit the CFRP reinforcement to bend in a certain curvature radius, so that the CFRP reinforcement is prevented from being damaged or even broken due to excessive bending;
3. the prestress is transversely applied through the prestress adjusting mechanism taking the jack as main equipment, so that on one hand, large-tonnage construction can be realized, on the other hand, the construction speed is high, time and labor are saved, and the construction efficiency is high;
4. the prestress is transversely applied through the prestress adjusting mechanism, on one hand, after the CFRP reinforcement is tensioned to the target prestress by the prestress adjusting mechanism, the steering block is locked on the tightening screw through the compression nut, so that prestress loss can be avoided; on the other hand, the compression nut can easily disassemble the prestress adjusting mechanism after compressing the steering block, so that the construction cost is greatly reduced;
5. after the prestressing force is applied, the oblique downward pulling force acting on the two ends of the structural member to be reinforced through the end fixing mechanism provides the negative bending moment for resisting the load and the axial pressure for inhibiting the crack, and meanwhile, the jacking force vertically transmitted by the stay bar plays a role in elastic support, so that the technical problem of mid-span downwarping of the structural member to be reinforced is solved pertinently;
6. the anchor device can adaptively adjust the included angle of the anchor device relative to the structural member to be reinforced under the action of the first direction rotating shaft in the process of applying prestress to the CFRP reinforcement device, so that the longitudinal stress concentration between the CFRP reinforcement device and the anchor device caused by the section change and the material rigidity change is effectively solved, the notch effect of the end part of the CFRP reinforcement device is eliminated, the end part of the CFRP reinforcement device is prevented from being damaged, and the anchor device is more suitable for large-tonnage structure construction; meanwhile, when aiming at large tonnage construction, the CFRP reinforcement can be formed by compounding a plurality of layers of CFRP plates, and the reinforcement effect can be greatly improved by matching with corresponding anchors;
7. the anchor device can adaptively turn under the action of the second direction rotating shaft so as to automatically adjust to balance in the tensioning process of the CFRP reinforcement, the force transmission path is clear and direct, and the axial tension of the CFRP reinforcement can be always ensured, so that the inside of the CFRP reinforcement is ensured not to be bent, the CFRP reinforcement is uniformly stressed, and the CFRP reinforcement is prevented from being damaged or even broken in the tensioning process;
8. the anchor can be replaced freely according to the actual condition of the structural member to be reinforced, the reinforcing form of the CFRP material, the prestress application and other factors, so that the universality of the end fixing mechanism is improved, and the application range is wider;
9. the supporting rods are fixedly connected with the structural member to be reinforced through the connecting plates, so that the stress area of the structural member to be reinforced can be increased, vertical loads are dispersed, and deformation or damage of the structural member to be reinforced and/or the supporting mechanism caused by improper local stress is avoided.
Drawings
In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic view showing the structure of a reinforcement system in an initial state in accordance with the first embodiment;
fig. 2 is a partial enlarged view of a portion a in fig. 1;
fig. 3 is a partial enlarged view of a portion B in fig. 1;
FIG. 4 is a schematic view of the structure of the reinforcement system after the construction is completed in the first embodiment;
fig. 5 is a partial enlarged view of a portion C in fig. 4;
FIG. 6 is a flow chart of the construction method in the first embodiment;
reference numerals in the drawings: 1-structural member to be reinforced, 2-CFRP reinforcement, 3-end fixing mechanism, 4-supporting mechanism, 41-base, 5-tightening screw, 6-compression nut, 7-steering block, 8-prestressing force adjusting mechanism, 81-counter force plate, 82-jack, 83-limiting plate, 42-supporting rod, 31-anchor seat, 32-connecting piece, 33-anchor, 34-first direction rotating shaft and 35-second direction rotating shaft.
Detailed Description
Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative and intended to explain the present invention and should not be construed as limiting the invention.
In the description of the present invention, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate describing the present invention and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention. Furthermore, in the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.
Fig. 1 to 5 show a first embodiment of the present invention: the utility model provides a tightening type external prestressing force CFRP material reinforcement system, includes wait to consolidate structure 1 and CFRP reinforcement 2, CFRP reinforcement 2 both ends respectively through tip fixed establishment 3 with wait to consolidate structure 1 and link to each other be provided with at least one supporting mechanism 4 on waiting to consolidate structure 1, supporting mechanism 4 includes base 41, it tightens up screw 5 to erect on the base 41, it is provided with gland nut 6 and turning block 7 on the screw 5 to tighten up, just CFRP reinforcement 2 is located turning block 7 with between the base 41 still detachable is provided with prestressing force adjustment mechanism 8 on the base 41, prestressing force adjustment mechanism 8 is used for adjusting turning block 7 is in tighten up the height on the screw 5.
Referring to fig. 1 and 2, in the embodiment, the prestress adjusting mechanism 8 includes a reaction plate 81 and a jack 82, the reaction plate 81 is detachably mounted at the upper end of the tightening screw 5, and the jack 82 is abutted between the reaction plate 81 and the steering block 7. In order to better limit the acting direction of the jack 82, a limiting plate 83 is mounted on the jack 82, and a through hole for inserting the tightening screw 5 is reserved on the limiting plate 83. Preferably, in order to limit the sliding direction of the steering block 7, at least two tightening screws 5 are provided, and a reaction plate 81 is fixedly mounted between the tightening screws 5.
As can be seen from fig. 2, in order to disperse the load applied to the supporting mechanism 4 when the supporting mechanism is abutted against the structural member 1 to be reinforced, the supporting mechanism 4 further includes at least two supporting rods 42, the upper ends of the supporting rods 42 are fixed on the structural member 1 to be reinforced through connecting plates, and the lower ends of the supporting rods 42 are connected with the base 41. Preferably, four support rods 42 are provided, the upper ends of the four support rods 42 are respectively connected with the structural member 1 to be reinforced through a connecting plate, and the lower ends of the four support rods 42 are connected to the base 41 in a folding manner.
As shown in fig. 3, in order to adapt the anchor 33 to the rotation of the CFRP reinforcement 2 in any direction during the tensioning process, the end fixing mechanism 3 includes an anchor seat 31, a connecting piece 32 and an anchor 33, the connecting piece 32 is connected with the anchor seat 31 through a first direction rotating shaft 34, the connecting piece 32 is hinged with the anchor 33 through a second direction rotating shaft 35, and the central axis of the first direction rotating shaft 34 is orthogonal to the central axis of the second direction rotating shaft 35.
In this embodiment, the anchor 33 is any one of a flat anchor, a wedge anchor, or a wave anchor. The anchoring form may take the form of one or more of adhesive, clip or friction anchors. Preferably, in order to meet the construction requirement of the large tonnage structure, the CFRP reinforcement 2 is formed by stacking a plurality of layers of CFRP plates, and the anchor 33 is correspondingly provided with an anchor interface of the plurality of layers of CFRP plates. It will be appreciated that, in practical applications, the CFRP reinforcement 2 may be one or more combinations of CFRP plates, CFRP cables or CFRP grids, such as a CFRP plate-CFRP grid composite, multiple CFRP cable windings, multiple layers of CFRP plates, etc., in order to meet different construction requirements.
Referring to fig. 1, 4, 5 and 6, based on the above-described structure, the present embodiment further provides a construction method, which includes the following steps:
s1: two ends of the CFRP reinforcement 2 are respectively arranged on the structural member 1 to be reinforced through end fixing mechanisms 3;
s2: a supporting mechanism 4 is arranged between the two end fixing mechanisms 3 at a predetermined interval;
s3: a tightening screw 5 is arranged on a base 41 of the supporting mechanism 4, and a steering block 7 and a compression nut 6 are sequentially arranged on the tightening screw 5, so that the CFRP reinforcement 2 is positioned between the steering block 7 and the base 41;
s4: the prestress adjusting mechanism 8 is arranged on the base 41, and the height of the steering block 7 is adjusted through the prestress adjusting mechanism 8;
s5: the steering block 7 is pressed tightly through the pressing nut 6;
s6: dismantling the prestress adjusting mechanism 8;
s7: and cutting off redundant tightening screws 5 above the compression nuts 6.
In particular, an adhesive is applied between the CFRP reinforcement 2 and the deflector block 7 in order to improve the stability of the system.
It will be appreciated that the structural member 1 to be reinforced is any one of a metal structural member, a concrete structural member, a wooden structural member or a composite structural member adapted to bear load.
It should be noted that the initial length, tensile control stress, and elastic modulus of the CFRP material, as well as the support mechanism height and the horizontal distance of the end fixing mechanism to the support mechanism can be measured by the instrument during construction. Given the initial length, tensile control stress, and modulus of elasticity of the CFRP material, as well as the support mechanism height and the horizontal distance of the end fixing mechanism to the support mechanism, the head space height between the deflector plate and the base can be calculated according to the following formula (this example is typical of two support mechanisms, other examples are in the form of a single support mechanism, more than two support mechanisms, parabolic ropes, etc.), and so forth.
Wherein: w is the height of a reserved space between the steering plate and the base;
l—initial length of CFRP material;
h, the height of the supporting mechanism;
s-horizontal distance from the end fixing mechanism to the supporting mechanism;
sigma-CFRP material tension control stress;
α 1 、α 2 -stretching the included angle between the front and rear CFRP materials and the beam bottom;
e-elastic modulus of CFRP material;
epsilon-strain value of CFRP material.
In summary, in the invention, only one section of CFRP reinforcement 2 is used to realize external prestress reinforcement, so that only a fixing mechanism is needed to be arranged at the end part of one section of CFRP reinforcement 2, thereby greatly reducing the number of anchors 33 required for construction, facilitating the simplification of the process of tensioning the CFRP reinforcement 2, reducing the construction cost and improving the construction efficiency; in the prestressing process, the steering block 7 can limit the CFRP reinforcement 2 to bend in a certain curvature radius, so that the CFRP reinforcement 2 is prevented from being damaged or even broken due to excessive bending; the prestress is transversely applied through the prestress adjusting mechanism 8 taking the jack 82 as main equipment, so that on one hand, large-tonnage construction can be realized, on the other hand, the construction speed is high, time and labor are saved, and the construction efficiency is high; the prestress is transversely applied through the prestress adjusting mechanism 8, on the one hand, after the CFRP reinforcement 2 is tensioned to the target prestress by the prestress adjusting mechanism 8, the prestress loss can be avoided by locking the steering block 7 on the tightening screw 5 through the compression nut 6; on the other hand, the compression nut 6 can easily disassemble the prestress adjusting mechanism 8 after compressing the steering block 7, so that the construction cost is greatly reduced; after the prestressing force is applied, the oblique downward pulling force acting on the two ends of the structural member 1 to be reinforced through the end fixing mechanism 3 provides a negative bending moment for resisting load and axial pressure for inhibiting cracks, and meanwhile, the jacking force vertically transmitted by the stay bar plays a role in elastic support, so that the technical problem of mid-span downward deflection of the structural member 1 to be reinforced is solved pertinently; the anchor 33 can adaptively adjust the included angle of the anchor 33 relative to the structural member 1 to be reinforced under the action of the first direction rotating shaft 34 in the process of applying prestress to the CFRP reinforcement 2, so that the longitudinal stress concentration between the CFRP reinforcement 2 and the anchor 33 caused by the section change and the material rigidity change is effectively treated, the notch effect of the end part of the CFRP reinforcement 2 is eliminated, the end part of the CFRP reinforcement 2 is prevented from being damaged, and the CFRP reinforcement is more suitable for large-tonnage structural construction; meanwhile, when aiming at large tonnage construction, the CFRP reinforcement 2 can be formed by compounding a plurality of layers of CFRP plates, and the matched corresponding anchor 33 can greatly improve the reinforcement effect; the anchor 33 can be adaptively turned under the action of the second direction rotating shaft 35 so as to automatically adjust to balance in the tensioning process of the CFRP reinforcement 2, so that a force transmission path is clear and direct, and the axial tension of the CFRP reinforcement 2 can be always ensured, so that the inside of the CFRP reinforcement 2 is ensured not to be bent, the CFRP reinforcement 2 is uniformly stressed, and the CFRP reinforcement 2 is prevented from being damaged or even broken in the tensioning process; the anchor 33 can be freely replaced according to the actual condition of the structural member 1 to be reinforced, the reinforcing form of the CFRP material, the prestress application and other factors, so that the universality of the end fixing mechanism 3 is improved, and the application range is wider; the supporting rod 42 is fixedly connected with the structural member 1 to be reinforced through the connecting plate, so that the stress area of the structural member 1 to be reinforced can be increased, and the vertical load is dispersed, so that the deformation or damage of the structural member 1 to be reinforced and/or the supporting mechanism 4 caused by improper local stress is avoided.
The above disclosure is only a preferred embodiment of the present invention, and it should be understood that the scope of the invention is not limited thereto, and those skilled in the art will appreciate that all or part of the procedures described above can be performed according to the equivalent changes of the claims, and still fall within the scope of the present invention.
Claims (9)
1. The tightening type external prestress CFRP material reinforcing system comprises a structural member to be reinforced and a CFRP reinforcing member, and is characterized in that two ends of the CFRP reinforcing member are respectively connected with the structural member to be reinforced through end fixing mechanisms, at least one supporting mechanism is arranged on the structural member to be reinforced and comprises a base, a tightening screw is erected on the base, a compression nut and a turning block are arranged on the tightening screw, the CFRP reinforcing member is positioned between the turning block and the base, and a prestress adjusting mechanism is further detachably arranged on the base and used for adjusting the height of the turning block on the tightening screw;
the prestress adjusting mechanism comprises a counter-force plate and a jack, wherein the counter-force plate is detachably arranged at the upper end of the tightening screw, and the jack is abutted between the counter-force plate and the steering block.
2. The tightening type in-vitro prestress CFRP material reinforcement system of claim 1, wherein a limiting plate is installed on the jack, and a through hole for inserting a tightening screw is reserved on the limiting plate.
3. The tightening type in-vitro prestress CFRP material reinforcement system of claim 1 or 2, wherein the support mechanism further comprises at least two support rods, the upper ends of the support rods are fixed on the structural member to be reinforced through connecting plates, and the lower ends of the support rods are connected with the base.
4. The tightening type external prestress CFRP material reinforcement system of claim 1, wherein the end fixing mechanism comprises an anchor seat, a connecting piece and an anchor, the connecting piece is connected with the anchor seat through a first direction rotating shaft, the connecting piece is hinged with the anchor through a second direction rotating shaft, and the central axis of the first direction rotating shaft is orthogonal with the central axis of the second direction rotating shaft.
5. The tightening type in-vitro prestress CFRP material reinforcement system of claim 4, wherein said CFRP reinforcement is one or a combination of more of CFRP plates, CFRP cables or CFRP grids, and said anchor is any one of a flat plate anchor, a wedge anchor or a wave anchor.
6. The tightening type in-vitro prestress CFRP material reinforcement system of claim 4, wherein said CFRP reinforcement is formed by overlapping multiple layers of CFRP plates, and anchoring interfaces of the multiple layers of CFRP plates are correspondingly arranged on the anchor.
7. A method of constructing a tightening type in vitro prestressed CFRP material reinforcing system according to any of claims 1-6, comprising the steps of:
s1: two ends of the CFRP reinforcement are respectively arranged on the structural member to be reinforced through end fixing mechanisms;
s2: a supporting mechanism is arranged between the two end fixing mechanisms at a preset interval;
s3: a tightening screw is arranged on a base of the supporting mechanism, and a steering block and a compression nut are sequentially arranged on the tightening screw, so that the CFRP reinforcement is positioned between the steering block and the base;
s4: the prestress adjusting mechanism is arranged on the base, and the height of the steering block is adjusted through the prestress adjusting mechanism;
s5: the steering block is pressed tightly through the pressing nut;
s6: dismantling the prestress adjusting mechanism;
s7: and cutting off redundant tightening screws above the compression nuts.
8. The construction method according to claim 7, wherein an adhesive is applied between the CFRP reinforcement and the knuckle before the knuckle is pressed in step S5.
9. The method according to claim 8, wherein the structural member to be reinforced is any one of a metal structural member, a concrete structural member, a wooden structural member, and a composite structural member.
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|---|---|---|---|---|
| EP3690167A1 (en) * | 2019-02-01 | 2020-08-05 | S & P Clever Reinforcement Company AG | Method for strengthening concrete or timber structures using cfrp strips and concrete or timber structures strengthened by this method |
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| KR20060003972A (en) * | 2004-07-05 | 2006-01-12 | 강신량 | Reinfocing method for beam and girder using external post-tension and apparatus therefor |
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