CN113047454B - FRP steel concrete column and steel beam composite joint and installation method - Google Patents

Abstract

The invention relates to the technical field of building structural components, in particular to a composite node of an FRP steel concrete column and a steel beam and an installation method. Including FRP double I-shaped steel concrete columns, beam-column connectors and H-shaped steel beams, FRP double I-shaped steel concrete columns include the upper FRP double I-shaped steel concrete columns and the lower FRP double I-shaped steel concrete columns, the upper FRP double I-shaped steel concrete columns and the lower FRP double I-shaped steel concrete columns are connected by connecting cylinders. It has good corrosion resistance, and is transported to the site for assembly and assembly through bolted connection, which improves the integrity of the structure and the bearing capacity of the column.

Description

FRP steel concrete column and steel beam composite joint and installation method

technical field

The invention relates to the technical field of building structural components, in particular to a composite node of an FRP steel concrete column and a steel beam and an installation method.

Background technique

With the development of social economy, the construction industry is developing in the direction of optimizing industrial structure, promoting prefabricated buildings and green buildings, and its transformation has become an inevitable trend of social and economic development.

Although traditional reinforced concrete buildings have strong compressive capacity, their bending capacity is insufficient. The use of CFST structure can effectively exert the respective advantages of steel and concrete, and at the same time overcome the shortcoming that the steel tube structure is prone to local buckling. However, for coastal areas, the CFST structure is prone to corrosion, which will reduce the cross-section of the components and reduce the bearing capacity, especially the "rust pit" caused by corrosion increases the possibility of brittle failure of the steel structure, which also seriously affects the durability of the steel structure.

In the past 20 years, fiber-reinforced polymers (FRP) have become more and more popular as a cladding material for reinforcement and earthquake resistance of reinforced concrete columns. In recent years, FRP pipe has been widely used in more new steel-concrete structures because of its thermal expansion coefficient similar to that of concrete. The interior of traditional FRP concrete columns is plain concrete or reinforced concrete. The study found that under the action of strong earthquakes, the FRP outer tube will buckling after the built-in concrete is damaged.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the above-mentioned defects existing in the prior art, and propose a combined node of an FRP steel concrete column and a steel beam and an installation method.

In order to achieve the above purpose, a composite node of an FRP concrete column and a steel beam of the present invention includes an FRP double I-shaped steel concrete column, a beam-column connector and an H-shaped steel beam, and the FRP double I-shaped steel concrete column includes an upper FRP double I-shaped steel concrete column and the lower FRP double I-shaped steel-concrete column, the upper FRP double-I-shaped steel-concrete column and the lower FRP double-I-shaped steel-concrete column are connected by connecting cylinders;

The FRP double I-shaped steel-concrete column includes an outer casing and a double I-shaped steel skeleton located on the inner side of the outer casing. The double I-shaped steel skeleton includes cross ribs, reinforcing steel fixing plates and plug plates located on four sides respectively, and the width of the plug plates is smaller than that of the FRP double I. The width of the inner wall of the sectioned steel concrete column, the four rib plates of the cross rib are provided with long hole grooves along the vertical direction, the distances from each long hole groove to the center of the cross rib are equal, and the center of the steel fixing plate is provided with a round hole, surrounded by There is a rebar socket I, and the rebar fixing plate is installed on the side of the cross rib with the long hole groove;

The beam-column connector includes an upper ring plate, a lower ring plate, a core cylinder and a side plate, the inner wall diameter of the core cylinder is larger than the outer wall diameter of the connecting cylinder, and the upper and lower ends of the core cylinder are respectively installed with an upper ring plate and a side plate. The lower ring plate, the center of the upper ring plate and the lower ring plate are provided with a circular hole, and there are reinforcement holes II around them. The cylinder is connected vertically;

The reinforcing bars of the upper FRP double I-shaped steel concrete column pass through the steel rebar socket II of the upper ring plate to connect with the beam-column connector, and the reinforcing bar of the lower FRP double I-shaped steel concrete column passes through the steel reinforcement hole II of the lower ring plate and is connected to the beam-column connector Connection, the connecting cylinder passes through the core cylinder of the beam-column connector, and is respectively inserted with the cross rib of the double I-shaped steel skeleton of the upper FRP double I-shaped steel concrete column and the lower FRP double I-shaped steel concrete column, and the H-shaped steel beam. The flange is overlapped with the ring plate of the beam-column connector, and the web of the H-shaped steel beam is overlapped with the side plate.

Further, the flange of the H-shaped steel beam is overlapped with the ring plate of the beam-column connector through the connecting plate I and the connecting plate II, and the web plate and the side plate of the H-shaped steel beam are overlapped through the connecting plate III.

The reinforcing bars of the upper FRP double I-shaped steel concrete column and the upper ring plate are connected by nuts, and the steel bars of the lower FRP-double I-shaped steel concrete column and the lower ring plate are connected by nuts.

The outer tube of the upper FRP double I-shaped steel concrete column and the lower FRP double I-shaped steel concrete column are inserted into the double I-shaped steel frame, which has a restraining effect on the FRP outer tube and prevents it from buckling, which can improve the flexural performance of the FRP double I-shaped steel concrete column.

The outer tube of FRP double I-shaped steel concrete column adopts FRP material, which can effectively improve corrosion resistance and durability.

The upper flange of the H-shaped steel beam and the upper ring plate, the lower flange and the lower ring plate of the H-shaped steel beam, and the web plate and the side plate of the H-shaped steel beam are respectively connected by high-strength bolts.

The reinforcing bar of FRP double I-shaped steel concrete column is FRP bar, which has the advantages of light weight, high tensile strength, strong corrosion resistance, and strong material bonding ability.

The connecting cylinders are respectively inserted into the long hole grooves of the cross rib of the double I-shaped steel frame of the upper FRP double I-shaped steel concrete column and the lower FRP double I-shaped steel concrete column to improve the integrity of the FRP double I-shaped steel concrete column.

The present invention includes an installation method of the above-mentioned concrete column and steel beam composite node, comprising the following steps;

The first step: insert the double I-shaped steel skeleton into the inner wall of the outer tube of the upper FRP double I-shaped steel concrete column and the lower FRP double I-shaped steel concrete column respectively, and the long hole groove of the double I-shaped steel skeleton of the upper FRP double I-shaped steel concrete column faces toward the inner wall. down, the long hole groove of the double I-shaped steel skeleton of the lower FRP double-I-shaped steel-concrete column faces upwards;

Step 2: Align the reinforcement socket II of the lower ring plate of the beam-column connector with the reinforcement socket I of the reinforcement fixing plate of the lower FRP double I-shaped steel concrete column, and the reinforcement will penetrate through the reinforcement socket II of the lower ring board. Insert the lower ring plate and the reinforcing bar fixing plate in turn, and the upper end of the reinforcing bar is fixedly connected by tightening the nut;

The third step: pass the connecting cylinder through the core cylinder of the beam-column connector, and insert it into the long hole groove of the double I-shaped steel skeleton of the lower FRP double-I-shaped steel concrete column;

Step 4: Insert the upper part of the connecting cylinder into the long hole groove of the double I-shaped steel skeleton of the upper FRP double-I-shaped steel concrete column, the steel bar is inserted from the steel bar hole II of the upper ring plate, and then inserted into the upper ring plate and the steel bar is fixed in turn The lower end of the steel bar is fixedly connected by tightening the nut;

Step 5: The upper and lower flanges of the H-shaped steel beam are respectively overlapped with the upper ring plate and the lower ring plate through the connecting plate I and the connecting plate II, and the web plate and the side plate of the H-shaped steel beam are overlapped through the connecting plate III. catch;

The sixth step: pour concrete into the interior of the FRP double-I-shaped steel-concrete column through the opening of the upper FRP double-I-shaped steel-concrete column, so that the connection part forms a whole through the occlusal effect of the concrete.

The beneficial effects of the present invention are:

The present invention is a composite node of FRP steel concrete column and steel beam designed based on the vertical splicing force transmission device. The steel of the entire node can be processed and manufactured in the factory, and transported to the site for assembly and assembly through bolt connection, avoiding welding. Quality problems such as hot and cold cracks and mechanical defects such as stress concentration;

The outer tube of the FRP steel concrete column in the present invention adopts FRP material, which has good corrosion resistance, can well prevent the oxidation corrosion of the steel skeleton inside the steel tube, and improves the durability of the structure;

The double I-shaped steel skeleton built in the FRP steel concrete column in the present invention has a constraining effect on the concrete in the steel tube, so that it is compressed in multiple directions, and the bearing capacity of the structure is improved; Improve the flexural performance of the structure; in addition, the built-in double I-shaped steel frame can act as the longitudinal reinforcement of the FRP column to improve the ductility of the structure;

The upper FRP double I-shaped steel-concrete column and the lower FRP double-I-shaped steel-concrete column in the present invention are assembled into one through the slotted groove connecting the steel pipe and the steel skeleton, which avoids the problem that the upper and lower columns of the node are independent, and realizes the assembled structure. At the same time, it also improves the integrity of the structure, which can improve the bearing capacity of the columns, and achieve the purpose of strong columns and weak beams.

Description of drawings

Fig. 1 is the structural representation of the combination node of the present invention;

Fig. 2 is the structural decomposition schematic diagram of the combined node of the present invention;

Fig. 3 is the structural decomposition schematic diagram of the lower FRP double I-shaped steel concrete column;

Fig. 4 is the structural decomposition schematic diagram of double I-shaped steel skeleton;

Fig. 5 is the structural representation of beam-column connector;

Figure 6(a) is a schematic diagram of setting up an outsourcing pipe;

Figure 6(b) is a schematic diagram of the connection between the double I-shaped steel frame and the outer tube;

Fig. 6 (c) is the schematic diagram of the second step in the installation method;

Fig. 6 (d) is the schematic diagram of the third step in the installation method;

Fig. 6 (e) is the schematic diagram of the fourth step in the installation method;

Figure 6(f) is a schematic diagram of the fifth step in the installation method.

In the figure: 1. FRP double I-shaped steel concrete column; 2. Beam-column connector; 3. H-shaped steel beam; 4. Upper FRP double I-shaped steel concrete column; 5. Lower FRP double I-shaped steel concrete column; 6. Connection circle Cylinder; 7. Double I-shaped steel frame; 8. Cross rib; 9. Insert plate; 10. Reinforcing plate; 11. Long hole groove; 12. Reinforcing bar; 13. Upper ring plate; 14. Lower ring plate; 15. Core cylinder; 16, side plate; 17, connecting plate I; 18, connecting plate II; 19, connecting plate III.

Detailed ways

In order to make the above objects, features and advantages of the present invention more clearly understood, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

In the following description, specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar promotions without departing from the connotation of the present invention. Accordingly, the present invention is not limited by the specific embodiments disclosed below.

As shown in Fig. 1 and Fig. 2, the FRP steel concrete column and steel beam combined node of the present invention includes FRP double I-shaped steel concrete column 1, beam-column connector 2 and H-shaped steel beam 3, FRP double I-shaped steel concrete column 1. It consists of an upper FRP double I-shaped steel concrete column 4 and a lower FRP double I-shaped steel concrete column 5. The upper FRP double I-shaped steel concrete column 4 and the lower FRP double I-shaped steel concrete column 5 are connected by a connecting cylinder 6.

The upper FRP double I-shaped steel-concrete column 4 and the lower FRP double-I-shaped steel-concrete column 5 both include an outer tube and a double I-shaped steel frame 7 . Figures 3 and 4 are schematic structural diagrams of the lower FRP double I-shaped steel concrete column 5. In this embodiment, the lower FRP double I-shaped steel concrete column 5 is used as an example to introduce the structure of the FRP double I-shaped steel concrete column. The inner wall of the outer tube is provided with a double I-shaped steel frame 7, the double I-shaped steel frame 7 includes a cross rib 8, a plug board 9 and a reinforcing bar fixing plate 10 on four sides, and the width of the four plug boards 9 is smaller than the FRP double I-shaped steel concrete column outsourcing The width of the inner wall of the tube. The cross rib 8 is formed by connecting four rib plates arranged in a vertical direction. The adjacent rib plates are vertically connected, and the four rib plates are connected together to form a cross rib. The four rib plates are respectively provided with opening grooves 11 along the vertical direction, and the distances from the four opening grooves to the center of the cross rib are equal. The four sides of the outer tube of the concrete column are inserted in such a way that the inner walls of the four sides are fitted. The reinforcing bar fixing plate 10 is installed on the side of the cross rib with the long hole groove. The middle of the reinforcing bar fixing plate 10 is provided with a circular hole, which can be used as a channel for pouring concrete into the lower FRP double I-shaped steel concrete column. There is a rebar socket I, and the rebar 12 is inserted into the interior of the FRP-double I-shaped steel-concrete column from the rebar socket I of the rebar fixing plate 10.

As shown in FIG. 5 , the beam-column connector includes an upper ring plate 13 , a lower ring plate 14 , a core cylinder 15 and a side plate 16 , the inner wall diameter of the core cylinder 15 is larger than the outer wall diameter of the connecting cylinder 6 , and the core cylinder 15 The upper and lower ends of the upper ring plate 13 and the lower ring plate 14 are respectively installed, and the round holes of the upper ring plate 13 and the lower ring plate 14 are provided with reinforcement holes II, and the side plates 16 are respectively connected with the upper ring plate 13 and the lower ring plate 14. The ring plate 14 and the core cylinder 15 are connected vertically.

The connecting cylinder 6 passes through the core cylinder 15 of the beam-column connector, and is inserted into the long hole grooves of the cross ribs in the double I-shaped steel frame 7 of the upper FRP double I-shaped steel concrete column 4 and the lower FRP double I-shaped steel concrete column 5 respectively 11. The reinforcing bar 12 of the upper FRP double I-shaped steel concrete column 4 passes through the steel bar hole II of the upper ring plate 13, and is connected with the beam-column connector 3 through a nut, and the steel bar 12 of the lower FRP double I-shaped steel concrete column 5 is connected. Pass through the rebar socket II of the lower ring plate 14, and connect with the beam-column connecting piece 3 through a nut. The flange of the H-shaped steel beam 3 and the upper and lower ring plates of the beam-column connector 2 are overlapped by the connecting plate I17 and the connecting plate II18, and the web plate of the H-shaped steel beam 3 and the side plate 16 are overlapped by the connecting plate III19. .

The beam-column connector 2 of FIG. 1 , the outer casing of the upper FRP double I-shaped steel concrete column 4 and the lower FRP double I-shaped steel concrete column 5 , the H-shaped steel beam 3 and the double I-shaped steel frame 7 of FIG. 2 are all prefabricated in the factory in advance Complete, just install it on site.

The installation method of the above-mentioned FRP steel-concrete column and steel beam composite joint includes the following installation steps, as shown in Figures 6(a) to 6(f).

The first step, the double I-shaped steel skeleton 7 is inserted into the inner wall of the outer tube of the upper FRP double I-shaped steel concrete column 4 and the lower FRP double I-shaped steel concrete column 5 respectively, the double I-shaped steel skeleton 7 of the upper FRP double I-shaped steel concrete column 4 The long hole grooves face downward, and the long hole grooves of the double I-shaped steel frame 7 of the lower FRP double I-shaped steel-concrete column 5 face upwards.

The second step is to align the reinforcement socket II of the lower ring plate 14 of the beam-column connector 2 with the reinforcement socket I of the reinforcement fixing plate 10 of the lower FRP double I-shaped steel concrete column 5, and the reinforcement 12 is inserted from the beam-column connector 2. The reinforcing bar hole II of the lower ring plate 14 is inserted into the lower ring plate 14 and the reinforcing bar fixing plate 10 in sequence, and the upper end of the reinforcing bar 12 is fixedly connected by tightening the nut.

In the third step, the connecting cylinder 6 is passed through the core cylinder 15 of the beam-column connector, and the connecting cylinder 6 is inserted into the long hole groove 11 of the double I-shaped steel frame 7 of the lower FRP double I-shaped steel concrete column 5 .

The 4th step, insert the upper part of the connecting cylinder 6 into the long hole groove 11 of the double I-shaped steel skeleton 7 of the upper FRP double I-shaped steel concrete column 4, and by connecting the cylinder 6, the upper FRP double I-shaped steel concrete column 4 is realized. The connection with the lower FRP double I-shaped steel concrete column 5 improves the integrity of the FRP double I-shaped steel concrete column. Reinforcing bars 12 are inserted through the rebar sockets II of the upper ring plate 13 of the beam-column connector 2, and are inserted into the upper ring plate 13 and the reinforcing bar fixing plate 10 in sequence.

In the fifth step, the upper and lower flanges of the H-shaped steel beam 3 are respectively overlapped with the upper ring plate 13 and the lower ring plate 14 through the connecting plate I17 and the connecting plate II18, and the web plate and the side plate 16 of the H-shaped steel beam 3 pass through the connecting plate. III19 lap joint.

The sixth step is to pour concrete into the interior of the FRP double I-shaped steel concrete column 1 through the opening of the upper FRP double I-shaped steel concrete column 4, so that the connecting part forms a whole through the occlusal effect of the concrete. In order to prevent the overflow of concrete, the upper FRP double I-shaped steel The gap between the concrete column 4, the beam-column connector 2 and the lower FRP double I-shaped steel concrete column 5 is filled with rubber material.

The combined node and installation method of the FRP steel-concrete column and steel beam provided by the present invention are described above in detail. The principles and implementations of the present invention are described herein by using specific examples, and the descriptions of the above embodiments are only used to help understand the method and the core idea of the present invention. It should be pointed out that for those skilled in the art, without departing from the principle of the present invention, several improvements and modifications can also be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention. The above description of the disclosed embodiments enables any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (9)

1. an FRP concrete column and a steel beam combined node, is characterized in that, comprises FRP double I-shaped steel concrete column (1), beam-column connector (2) and H-shaped steel beam (3), FRP double I-shaped steel concrete column (1) Including the upper FRP double I-shaped steel concrete column (4) and the lower FRP double I-shaped steel concrete column (5), the upper FRP double I-shaped steel concrete column (4) and the lower FRP double I-shaped steel concrete column (5) through the connecting circle The barrel (6) is connected; The FRP double I-shaped steel concrete column (1) includes an outer casing and a double I-shaped steel frame (7) located on the inner side of the outer casing. The insert plates (9) located on the four sides, the width of the insert plates (9) is smaller than the inner wall width of the FRP double I-shaped steel concrete column (1), and the four rib plates of the cross rib (8) are provided with long hole recesses along the vertical direction. The grooves (11), the distances from each long hole groove (11) to the center of the cross rib (8) are equal, the center of the reinforcing steel fixing plate (10) is provided with a round hole, and the surrounding are provided with reinforcing steel sockets I, and the reinforcing steel fixing plate (10) ) is installed on the side of the cross rib with the slotted slot; The beam-column connecting piece (2) comprises an upper ring plate (13), a lower ring plate (14), a core cylinder (15) and a side plate (16), and the inner wall diameter of the core cylinder (15) is larger than that of the connecting cylinder (6), the upper and lower ends of the core cylinder (15) are respectively installed with an upper ring plate (13) and a lower ring plate (14), and the center of the upper ring plate (13) and the lower ring plate (14) There are round holes, and reinforcement holes II are arranged around, the side plate (16) is located between the upper ring plate (13) and the lower ring plate (14), and is connected with the upper ring plate (13), the lower ring plate (14) and the The core cylinder (15) is connected vertically; The reinforcement bars (12) of the upper FRP double I-shaped steel concrete column (4) pass through the reinforcement holes II of the upper ring plate (13) to be connected with the beam-column connector (2), and the reinforcement bars of the lower FRP double I-shaped steel concrete column (5) (12) The reinforcing bar hole II passing through the lower ring plate (14) is connected to the beam-column connector (2), and the connecting cylinder (6) passes through the core cylinder (15) of the beam-column connector (2), and is connected to the beam-column connector (2). Plug with the cross rib (8) of the double I-shaped steel frame (7) of the upper FRP double I-shaped steel concrete column (4) and the lower FRP double I-shaped steel concrete column (5), respectively, and the flange of the H-shaped steel beam (3) It is overlapped with the ring plate of the beam-column connector (2), and the web of the H-shaped steel beam (3) is overlapped with the side plate (16). 2. The combined node of FRP concrete column and steel beam according to claim 1, characterized in that the flange of the H-shaped steel beam (3) is connected to the beam-column through connecting plate I (17) and connecting plate II (18) The ring plate of the piece (2) is overlapped, and the web plate of the H-shaped steel beam (3) is overlapped with the side plate (16) through the connecting plate III (19). 3. FRP concrete column and steel beam combined node according to claim 1, is characterized in that, the reinforcing bar (12) of upper FRP double I-shaped steel concrete column (4) is connected with upper ring plate (13) by nut, and the lower part is connected by nut. The reinforcing bars (12) of the FRP double I-shaped steel concrete column (5) are connected with the lower ring plate (14) through nuts. 4. FRP concrete column and steel beam composite node according to claim 1, is characterized in that, double I are all inserted in the outer casing of upper FRP double I-shaped steel concrete column (4) and lower FRP double I-shaped steel concrete column (5) Steel frame (7). 5. The FRP concrete column and steel beam combined node according to claim 1, wherein the outer tube of the FRP double I-shaped steel concrete column (1) adopts FRP material. 6. The FRP concrete column and steel beam combined node according to claim 1, wherein the upper flange of the H-shaped steel beam (3) and the upper ring plate (13), the lower part of the H-shaped steel beam (3) The flange and the lower ring plate (14), the web plate of the H-shaped steel beam (3) and the side plate (16) are respectively connected by bolts. 7 . The FRP concrete column and steel beam combined node according to claim 1 , wherein the reinforcing bars ( 12 ) of the FRP double I-shaped steel concrete columns ( 1 ) are FRP bars. 8 . 8. FRP concrete column and steel beam composite node according to claim 1, is characterized in that, connecting cylinder (6) and upper FRP double I-shaped steel concrete column (4) and lower FRP double I-shaped steel concrete column (5) respectively ) of the double I-shaped steel frame (7) is inserted into the long hole groove (11) of the cross rib (8). 9. An installation method of the concrete column and steel beam composite node according to any one of claims 1-8, characterized in that, comprising the following steps; The first step: insert the double I-shaped steel frame (7) into the inner wall of the outer tube of the upper FRP double I-shaped steel concrete column (4) and the lower FRP double I-shaped steel concrete column (5) respectively, and the upper FRP double I-shaped steel concrete column (4) ) of the double I-shaped steel skeleton (7) of the long-hole groove (11) facing downward, and the long-hole groove (11) of the double I-shaped steel skeleton (7) of the lower FRP double I-shaped steel concrete column (5) facing upward; Step 2: Align the reinforcing bar hole II of the lower ring plate (14) of the beam-column connector (2) with the reinforcing bar hole I of the reinforcing bar fixing plate (10) of the lower FRP double I-shaped steel concrete column (5). (12) penetrate through the reinforcing bar hole II of the lower ring plate (14), insert the lower ring plate (14) and the reinforcing bar fixing plate (10) in sequence, and the upper end of the reinforcing bar (12) is fixedly connected by tightening the nut; Step 3: Pass the connecting cylinder (6) through the core cylinder (15) of the beam-column connector (2), and insert it into the long hole of the double I-shaped steel frame (7) of the lower FRP double I-shaped steel concrete column (5). groove (11); Step 4: Insert the upper part of the connecting cylinder (6) into the long hole groove (11) of the double I-shaped steel skeleton (7) of the upper FRP double-I-shaped steel concrete column (4), and the reinforcement (12) from the upper ring plate ( 13) The rebar socket II is penetrated, and the upper ring plate (13) and the rebar fixing plate (10) are inserted in sequence, and the lower end of the rebar (12) is fixedly connected by tightening the nut; Step 5: The upper and lower flanges of the H-shaped steel beam (3) are overlapped with the upper ring plate (13) and the lower ring plate (14) through the connecting plate I (17) and the connecting plate II (18) respectively, The web plate of the H-shaped steel beam (3) is overlapped with the side plate (16) through the connecting plate III (19); The sixth step: pour concrete into the interior of the FRP double I-shaped steel concrete column (1) through the opening of the upper FRP double-I-shaped steel-concrete column (4), so that the connection part forms a whole through the occlusion of the concrete.

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