Hoist structure and construction method of prestressed concrete composite slab

Abstract

The application discloses a prestressed concrete composite slab and a lifting appliance structure thereof, and belongs to the field of fabricated buildings. The prestressed concrete composite slab comprises a prestressed concrete bottom plate, a concrete upper flange, a steel structure and a carbon fiber lifting ring. The concrete upper flange is located above the prestressed concrete bottom plate, and the lower end and the upper end of the steel structure are respectively cast in the prestressed concrete bottom plate and the concrete upper flange. The carbon fiber lifting ring is an annular structure formed by a carbon fiber cloth strip with a certain width, the bottom end of the carbon fiber lifting ring is connected with the steel structure, and the upper part of the carbon fiber lifting ring extends out of the top end of the concrete upper flange. The flexible carbon fiber cloth is made into a lifting ring, and is hoisted in cooperation with the lifting appliance structure. The prestressed concrete composite slab has the advantages of simple structure, high hoisting efficiency, lower cost, full play of the advantages of the steel rib prestressed concrete composite slab in high bending stiffness, reduced deformation of the prefabricated concrete bottom plate and the composite slab, and convenient transportation and stacking.

Description

Technical Field

[0001] The present invention relates to the field of prefabricated buildings, and in particular to a hanger structure and a construction method for a prestressed concrete composite slab. Background Art

[0002] Steel-ribbed prestressed concrete composite slabs are one of a series of steel-concrete composite slabs. They offer advantages such as excellent overall performance, superior crack resistance, high base plate rigidity, minimal or no support during construction, a thin base plate, and low deadweight. Steel-ribbed prestressed concrete composite slabs consist of a prestressed concrete base plate, steel ribs, and a concrete upper flange. The flexural rigidity provided by the concrete upper flange and steel ribs effectively controls the camber of the precast slab, providing the necessary flexural bearing capacity and rigidity during demolding, stacking, hoisting, and construction, thus preventing damage to the precast slab.

[0003] When making prestressed concrete composite slabs, the concrete upper flange is usually made in reverse, that is, when pouring the concrete upper wing, the steel ribs are on top and the concrete upper flange is on the bottom; after pouring the concrete of the upper flange and curing it to the specified strength, the steel ribs and the concrete upper flange become one; the steel ribs and the concrete upper flange are turned 180 degrees and placed on a formwork table with the prestressed bottom plate, the concrete of the bottom plate is poured, and after curing it to the specified strength, the prestressed steel bars are cut, and the steel rib prestressed concrete composite slab is completed.

[0004] Currently, the hoisting structure of prestressed concrete composite slabs usually uses steel lifting rings, and embedded steel bars are the most commonly used lifting method. During the production of prefabricated panels, this method generally anchors or welds bent steel bars to the base plate steel bars, and then pours the base plate concrete, so that the steel bars are embedded in the concrete base plate, forming steel lifting rings on the base plate that are exposed upward. During lifting, the crane's steel hook is passed through the exposed steel lifting rings on the composite slab for lifting. This method has the following disadvantages:

[0005] The prestressed concrete base slab is relatively thin, approximately 40mm thick. Embedding steel lifting rings in the base slab presents a safety hazard, as the rings can easily detach from the precast base slab, causing the composite slab to fall. Furthermore, securing the steel lifting rings to the base slab reinforcement is inconvenient and labor-intensive. When the steel lifting rings are installed on the precast base slab, the combined bending resistance of the base slab, steel ribs, and concrete upper flange cannot be fully utilized during the lifting process. Only the base slab, with its lower bending stiffness, is fully utilized. This necessitates the installation of a large number of steel lifting rings, increasing costs.

[0006] Another method for hoisting composite slabs is to fix steel lifting rings to steel ribs. During the production of precast panels, this method involves fixing bent steel lifting rings in a mold and casting them into an integral part of the concrete upper flange. The steel lifting rings are then anchored or welded to the reinforcement at the bottom of the slab. The bottom slab concrete is then poured, anchoring the steel lifting rings within the concrete bottom slab, forming steel lifting rings on the concrete upper flange. During lifting, the crane's steel hook is passed through the exposed steel lifting rings on the composite slab flange for hoisting. This method has the following drawbacks:

[0007] The steel lifting ring is a rigid lifting ring located above the upper flange of the precast composite slab. It is difficult to fix during the reverse production process of the concrete upper flange and the mold is relatively complex, which increases the loss of the template and the production cost. The layout position is prone to conflict with the steel ribs, and it is difficult to anchor the bottom reinforcement of the precast slab. The production process is relatively complicated. At the same time, because the steel lifting ring is exposed above the upper flange of the precast composite slab, it has an adverse effect on transportation and stacking. Because the steel hook of the crane has a certain size, the inner diameter of the ordinary steel lifting ring is generally not less than 40mm and the outer diameter is not less than 60mm. Since the composite layer concrete above the upper flange of the precast composite slab is 25mm, the steel lifting ring will be exposed on the upper surface of the composite slab by not less than 10mm after pouring, affecting the use of the floor slab in the later stage.

[0008] In addition, steel lifting rings are exposed at a certain height above the surface of precast concrete components to facilitate the insertion of steel hooks. After the components are hoisted and installed, two methods are generally used to deal with the exposed steel lifting rings: one is cutting, and the other is pouring concrete to bury them. The cutting method is time-consuming and labor-intensive, and is prone to environmental pollution (noise from electric saw cutting, light pollution from flame cutting, etc.) and safety hazards, and is relatively expensive. The pouring concrete burying method requires a thicker cast-in-place concrete, which must be thicker than the sum of the exposed height of the steel lifting ring and 20mm. This method is not suitable for components such as thin composite slabs, especially when the steel lifting ring is located on the upper flange of the concrete. Summary of the Invention

[0009] The present invention provides a sling structure and construction method for a prestressed concrete composite slab. Flexible carbon fiber cloth is made into a lifting ring, which cooperates with the sling structure for lifting. The structure is simple, the lifting efficiency is high, and the cost is lower. The advantage of the high bending rigidity of the steel-ribbed prestressed concrete composite slab can be fully utilized, the deformation of the precast concrete base plate and the composite slab can be reduced, and transportation and stacking are convenient.

[0010] The present invention provides the following technical solutions:

[0011] A prestressed concrete composite slab comprises a prestressed concrete base plate, wherein at least one set of superstructures is provided on the prestressed concrete base plate, each set of superstructures comprises a concrete upper flange, at least one steel structure and at least two carbon fiber suspension rings, wherein:

[0012] The concrete upper flange is located at a set height above the prestressed concrete bottom plate, the steel structure is located between the prestressed concrete bottom plate and the concrete upper flange, and the lower end and upper end of the steel structure are cast in the prestressed concrete bottom plate and the concrete upper flange respectively;

[0013] The carbon fiber hanging ring is an annular structure formed by a carbon fiber cloth strip of a certain width. The bottom end of the carbon fiber hanging ring is connected to the steel structure, and the upper part of the carbon fiber hanging ring extends upward from the top end of the concrete upper flange.

[0014] Furthermore, the steel structure is a steel rib, and the bottom end of the carbon fiber hanging ring is bonded to the steel rib by an adhesive.

[0015] Furthermore, the inner sides of both ends of the carbon fiber cloth strip are bonded together by an adhesive, and the outer side of one end of the carbon fiber cloth strip is bonded to the steel rib by an adhesive.

[0016] Furthermore, the steel rib is a Z-shaped steel rib or a C-shaped steel rib, and the outer side of one end of the carbon fiber cloth strip is bonded to the side of the Z-shaped steel rib or the C-shaped steel rib that does not have an upper flange through an adhesive.

[0017] Furthermore, the width of the carbon fiber cloth strip is 30-40 mm, and the bonding length between the carbon fiber cloth strip and the steel rib is not less than 30 mm.

[0018] Furthermore, the steel structure is a steel truss, which includes an upper chord steel bar, a lower chord steel bar and a web steel bar connecting the upper chord steel bar and the lower chord steel bar. The carbon fiber cloth strip passes from top to bottom through the arc-shaped transition structure sleeved on the upper chord steel bar and then the two ends are bonded to form a carbon fiber ring.

[0019] Furthermore, the inner side of one end of the carbon fiber cloth strip is bonded to the outer side of the other end.

[0020] Furthermore, the adhesive is epoxy resin adhesive or structural adhesive.

[0021] A sling structure for the aforementioned prestressed concrete composite slab includes a lifting ring connector and a sling connector, wherein the sling connector is connected above the lifting ring connector, and the lifting ring connector is provided with a flat accommodating groove for accommodating the carbon fiber lifting ring, wherein the width of the flat accommodating groove is not less than the width of the carbon fiber cloth forming the carbon fiber lifting ring.

[0022] Furthermore, the lifting ring connector is a pulley, the lifting rope connector is a hook, and the annular groove formed on the pulley serves as the flat receiving groove; the pulley is vertically arranged, and a vertical plate is provided on each side of the pulley, the lower parts of the two vertical plates are connected to the pulley through a horizontal pulley pin, and the upper parts of the two vertical plates are fixed together through an inter-plate connector, and the hook is fixed on the inter-plate connector.

[0023] Furthermore, one of the vertical plates includes an upper structure and a lower structure, and the upper structure and the lower structure are connected by a horizontal hinge pin to form a hinge structure that allows the lower structure to flip outward and upward, and the folding point between the upper structure and the lower structure is higher than the highest point of the pulley.

[0024] Furthermore, a pin cap is provided at one end of the pulley pin, and a locking pin hole perpendicular to the axis of the pulley pin is opened at the other end, a locking pin is inserted into the locking pin hole, an elastic locking ring is passed through the upper end of the locking pin, the elastic locking ring is sleeved on the pulley pin, and the lower end of the elastic locking ring sleeve is located between the lower end of the locking pin and the vertical plate, and the distance between the position where the locking pin passes through the elastic locking ring and the bottom end of the locking pin is greater than the maximum diameter of the elastic locking ring in the free state.

[0025] Furthermore, the pulley pin and the locking pin are respectively connected to the two vertical plates through connecting ropes, and the elastic locking ring is an elastic metal ring or an elastic rope ring.

[0026] Furthermore, the lifting ring connector is a shackle, and the sling connector is a bolt. The two free ends of the upper part of the shackle are connected by the bolt, and the bolt is used to connect with the chain sling. A straight groove is provided on the upper surface of the bottom of the shackle as the flat accommodating groove.

[0027] Furthermore, the lifting ring connector is a shackle, the sling connector is a hook, the two free ends of the upper part of the shackle are connected by a connecting pin, the hook is fixed on the connecting pin, and a straight groove is provided on the upper surface of the bottom of the shackle as the flat accommodating groove.

[0028] A method for preparing the aforementioned prestressed concrete composite slab comprises:

[0029] S1: Obtain a carbon fiber strip of required specifications, bend the carbon fiber strip into a ring-shaped carbon fiber ring, connect the lower end of the carbon fiber ring to the steel structure, and make the upper part of the carbon fiber ring extend upward to the top of the designed position of the concrete upper flange;

[0030] S2: Setting the formwork for the upper concrete flange, tying the steel bars of the upper concrete flange, wrapping at least the portion of the carbon fiber ring extending upward from the upper concrete flange with a film, turning the steel structure 180 degrees and placing it upside down at the designed position on the steel bars of the upper concrete flange, placing the wrapped carbon fiber ring vertically downward, and folding the bottom of the carbon fiber ring flat on the bottom of the formwork for the upper concrete flange;

[0031] S3: After pouring the concrete upper flange and curing it to the required strength, remove the formwork of the concrete upper flange, turn the concrete upper flange and the steel structure 180 degrees, and remove the film wrapping the carbon fiber ring;

[0032] S4: setting a formwork for the prestressed concrete bottom plate, placing transverse distribution steel bars of the prestressed concrete bottom plate, tensioning the prestressed steel bars placed on the transverse distribution steel bars, pouring concrete of the prestressed concrete bottom plate and curing it to the required strength before removing the formwork to obtain the prestressed concrete composite slab.

[0033] Furthermore, when the steel structure is a steel rib, in S1, the lower end of the carbon fiber hanging ring is connected to the steel rib in the following manner:

[0034] directly adhering the first end of the carbon fiber cloth strip to the steel rib with an adhesive, bending the carbon fiber cloth strip into a ring, and adhering the second end of the carbon fiber cloth strip to the first end with an adhesive;

[0035] Alternatively, the inner sides of both ends of the carbon fiber cloth strip are adhered to each other by adhesive to form a ring structure, and the outer side of one end of the carbon fiber cloth strip is adhered to the steel rib by adhesive.

[0036] Furthermore, when the adhesive is epoxy resin adhesive or structural adhesive, curing is performed for at least 24 hours after bonding.

[0037] A method for hoisting the prestressed concrete composite slab using the hoisting structure comprises:

[0038] S5: Connecting the carbon fiber lifting ring to the lifting ring connector, and making the carbon fiber lifting ring be located in the flat receiving groove, and connecting the sling connector to the sling;

[0039] S6: The hoisting machine hoists the prestressed concrete composite slab to the designed construction position through the sling;

[0040] S7: After the hoisting is completed, the carbon fiber lifting ring is fitted to the upper flange of the concrete, the superimposed layer concrete is poured, and the carbon fiber lifting ring is buried in the superimposed layer concrete.

[0041] The present invention has the following beneficial effects:

[0042] The present invention uses flexible carbon fiber cloth strips to make carbon fiber rings. The tensile strength of carbon fiber is very high, and the material is soft and can be deformed at will, making it a good ring material. Using carbon fiber rings instead of steel rings has a simpler manufacturing process, higher production efficiency, and lower cost. The carbon fiber rings are fixed to the steel structure (the hanging points are set on the steel structure), and are easy to fix to the steel structure and not easy to detach. This can give full play to the advantage of the large bending stiffness of the prestressed concrete composite slab, fully utilize the bending stiffness of the concrete upper flange and the steel structure, avoid and reduce the damage and deformation of the precast concrete base plate, and reduce the number of rings.

[0043] Because carbon fiber cloth is soft and deformable, it can adapt to production methods such as reverse production of the concrete upper flange. When reverse production of the concrete upper flange, the portion of the carbon fiber ring exposed by the concrete upper flange can be wrapped with plastic film. Before pouring the concrete for the concrete upper flange, the wrapped carbon fiber ring is placed vertically downward, and the excess portion at the bottom is folded and laid flat on the bottom of the formwork used to pour the upper flange concrete. The concrete for the concrete upper flange is then poured. After the formwork is removed, the ring is exposed to the concrete upper flange. After the concrete upper flange is poured and flipped into shape, the plastic film on the exposed carbon fiber ring is removed. A small amount of plastic film poured into the concrete interior has little impact and can be removed without force. As can be seen from the above, when reverse production of the concrete upper flange, there is no need to set a formwork at the carbon fiber ring, reducing formwork loss and production costs. In addition, the flexible carbon fiber ring does not affect transportation and stacking, which helps to ensure the flatness of the upper surface of the composite panel.

[0044] After the hoisting and installation are completed, when pouring the composite layer concrete on site, the carbon fiber ring is aligned with the concrete upper flange, and then the composite layer concrete is poured. The carbon fiber ring is buried in the composite layer concrete. No additional treatment is required and it does not affect the construction. There is no need to cut off the carbon fiber ring, nor is there a need to pour a thick concrete layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 A perspective view of a prestressed concrete composite slab (the steel structure is steel ribs) according to the present invention;

[0046] Figure 2 for Figure 1 Side view of;

[0047] Figure 3 This is a schematic diagram of the connection between the steel rib and the carbon fiber ring;

[0048] Figure 4 A perspective view of a prestressed concrete composite slab (the steel structure is a steel truss) according to the present invention;

[0049] Figure 5 for Figure 4sectional view of

[0050] Figure 6 The three-dimensional structure of the sling structure of Example 1 Figure 1 ;

[0051] Figure 7 The three-dimensional structure of the sling structure of Example 1 Figure 2 ;

[0052] Figure 8 A schematic diagram of a foldable vertical plate of a spreader structure of Example 1;

[0053] Figure 9 is a schematic diagram of a locking pin;

[0054] Figure 10 Schematic diagram of the connection between the carbon fiber lifting ring and the lifting fixture structure of Example 1;

[0055] Figure 11 A schematic diagram of the elastic locking ring of the locking pin when it is unlocked;

[0056] Figure 12 A schematic diagram of the locking pin after being locked by the elastic locking ring;

[0057] Figure 13 is a perspective view of the spreader structure of Example 2;

[0058] Figure 14 This is a schematic diagram of the disassembly and assembly of the spreader structure of Example 2;

[0059] Figure 15 Schematic diagram of the connection between the carbon fiber lifting ring and the lifting fixture structure of Example 2;

[0060] Figure 16 is a three-dimensional diagram of the spreader structure of Example 3;

[0061] Figure 17 This is a schematic diagram of the disassembly and assembly of the spreader structure of Example 3;

[0062] Figure 18 Schematic diagram of the connection between the carbon fiber lifting ring and the lifting fixture structure of Example 3. DETAILED DESCRIPTION

[0063] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0064] The embodiment of the present invention provides a prestressed concrete composite slab, such as Figure 1-5 As shown, it includes a prestressed concrete base plate 1, on which at least one set of superstructures 2 is arranged. Each set of superstructures 2 includes a concrete upper flange 3, at least one steel structure 4, 6 and at least two carbon fiber rings 5, wherein:

[0065] The concrete upper flange 3 is located at a set height above the prestressed concrete base plate 1, the steel structures 4 and 6 are located between the prestressed concrete base plate 1 and the concrete upper flange 3, and the lower and upper ends of the steel structures 4 and 6 are cast in the prestressed concrete base plate 1 and the concrete upper flange 3 respectively.

[0066] The carbon fiber ring 5 is an annular structure formed by a carbon fiber cloth strip of a certain width. The bottom end of the carbon fiber ring 5 is connected to the steel structures 4 and 6, and the upper part of the carbon fiber ring 5 extends upward from the top of the concrete upper flange 3.

[0067] The position of the carbon fiber lifting ring 5 on the steel structure 4, 6, that is, the designed lifting point position, can be determined according to actual calculations. For example, two or three carbon fiber lifting rings 5 ​​can be set on one steel structure 4, 6.

[0068] The present invention uses flexible carbon fiber cloth strips to make carbon fiber rings. The tensile strength of carbon fiber is very high, and the material is soft and can be deformed at will, making it a good ring material. Using carbon fiber rings instead of steel rings has a simpler manufacturing process, higher production efficiency, and lower cost. The carbon fiber rings are fixed to the steel structure (the hanging points are set on the steel structure), and are easy to fix to the steel structure and not easy to detach. This can give full play to the advantage of the large bending stiffness of the prestressed concrete composite slab, fully utilize the bending stiffness of the concrete upper flange and the steel structure, avoid and reduce the damage and deformation of the precast concrete base plate, and reduce the number of rings.

[0069] Because carbon fiber cloth is soft and deformable, it can adapt to production methods such as reverse production of the concrete upper flange. When reverse production of the concrete upper flange, the portion of the carbon fiber ring exposed by the concrete upper flange can be wrapped with plastic film. Before pouring the concrete for the concrete upper flange, the wrapped carbon fiber ring is placed vertically downward, and the excess portion at the bottom is folded and laid flat on the bottom of the formwork used to pour the upper flange concrete. The concrete for the concrete upper flange is then poured. After the formwork is removed, the ring is exposed to the concrete upper flange. After the concrete upper flange is poured and flipped into shape, the plastic film on the exposed carbon fiber ring is removed. A small amount of plastic film poured into the concrete interior has little impact and can be removed without force. As can be seen from the above, when reverse production of the concrete upper flange, there is no need to set a formwork at the carbon fiber ring, reducing formwork loss and production costs. In addition, the flexible carbon fiber ring does not affect transportation and stacking, which helps to ensure the flatness of the upper surface of the composite panel.

[0070] After the hoisting and installation are completed, when pouring the composite layer concrete on site, the carbon fiber ring is aligned with the concrete upper flange, and then the composite layer concrete is poured. The carbon fiber ring is buried in the composite layer concrete. No additional treatment is required and it does not affect the construction. There is no need to cut off the carbon fiber ring, nor is there a need to pour a thick concrete layer.

[0071] The present invention is not limited to a specific form of the steel structure, and two examples are given below.

[0072] Example 1:

[0073] The steel structure of this example can be a steel rib 4, such as Figure 1-3 As shown, the bottom end of the carbon fiber ring 5 is bonded to the steel rib 4 by an adhesive.

[0074] The inner sides of the two ends of the carbon fiber strip are bonded together with adhesive, and the outer side of one end of the carbon fiber strip is also bonded to the steel rib 4 with adhesive. Because the bonding strength between the carbon fiber strips is higher than the bonding strength between the carbon fiber strips and the steel rib 4, this bonding method can minimize the adhesion between the carbon fiber strips and the steel rib 4, effectively preventing the bonded parts from coming apart under the action of tension.

[0075] During bonding, the first end of the carbon fiber strip can be directly attached to the steel rib 4. After the carbon fiber strip is bent into a ring, the second end of the carbon fiber strip can be attached to the first end. Alternatively, the two ends of the carbon fiber strip can be attached to each other to form a complete ring, and then one end of the carbon fiber strip can be attached to the steel rib 4.

[0076] Specifically, the steel rib 4 can be a Z-shaped steel rib or a C-shaped steel rib, and the outer side of one end of the carbon fiber cloth strip is bonded to the side of the Z-shaped steel rib or the C-shaped steel rib without the upper flange by an adhesive to prevent the upper flange of the steel rib from affecting the carbon fiber ring 5.

[0077] In this example, the width of the carbon fiber cloth strip can be 30-40mm. Carbon fiber cloth has a very high tensile strength, typically greater than or equal to 3000MPa. The ultimate tensile bearing capacity of carbon fiber cloth is directly proportional to its width: the wider the carbon fiber cloth, the greater its ultimate tensile bearing capacity. Taking into account the material strength and the size of the lifting ring, the width of the carbon fiber cloth is preferably between 30-40mm. Tests have shown that a 300g carbon fiber cloth with a width of 30mm can have an ultimate bearing capacity of 9kN. For a standard steel-ribbed prestressed concrete composite slab with a width of 1200mm and a span of 3.9m, weighing approximately 100kg, with four lifting points and a dynamic coefficient of 1.5, each carbon fiber lifting ring bears a force of approximately 375N. The strength of the carbon fiber cloth can fully meet the requirements for lifting the composite slab.

[0078] The aforementioned adhesive can be epoxy resin glue or structural glue. Preferably, the bonding length between the carbon fiber cloth strips and the steel ribs is not less than 30mm, and the bonding length between the carbon fiber cloth strips is not less than 30mm. Tests have shown that when the carbon fiber cloth and the steel plate are bonded together using epoxy resin glue or structural glue (TSL-503 was selected in the test), when the carbon fiber cloth width is 30mm and the bonding length is not less than 30mm, the ultimate bearing capacity of the bonding interface is closely related to the bonding process, but is at least 1.5kN and can reach a maximum of 4kN. When failure occurs at the adhesive layer or the adhesive-steel interface, it can fully meet the requirements for lifting steel rib prestressed concrete composite slabs.

[0079] During bonding, mix adhesives A and B according to the epoxy resin adhesive's instructions for curing. Complete bonding within the pot life and allow to cure at room temperature. After one day of curing at 25°C, the epoxy resin adhesive generally reaches 75% of its rated strength, reaching the rated strength after seven days. Curing at too low a temperature will increase the curing time. In factory production, one day of curing is sufficient. The specific curing time and temperature should be determined based on the actual epoxy resin adhesive used.

[0080] Example 2:

[0081] The steel structure of this example can be a steel truss 6, such as Figure 4 、 5 As shown, the steel truss 6 includes an upper chord steel bar 7, a lower chord steel bar 8, and a web steel bar 9 connecting the upper chord steel bar 7 and the lower chord steel bar 8. After the carbon fiber cloth strip passes from top to bottom through the arc-shaped transition structure sleeved on the upper chord steel bar 7, the two ends of the carbon fiber cloth strip are bonded to form a carbon fiber ring 5.

[0082] The carbon fiber strips have poor shear resistance, so an arc-shaped transition structure, such as a transition sleeve or other arc-shaped parts, is provided at the connection with the upper chord steel bar 7 to ensure that the carbon fiber strips do not suffer shear failure.

[0083] The inner side of one end of the carbon fiber cloth strip is bonded to the outer side of the other end to prevent it from coming apart under the action of tension, and the bonding length is not less than 30 mm.

[0084] The embodiment of the present invention also provides the aforementioned hanger structure of the prestressed concrete composite slab, such as Figure 6-18 As shown, the sling structure includes ring connectors 10, 26, 29 and sling connectors 11, 27, 30. The sling connectors 11, 27, 30 are connected above the ring connectors 10, 26, 29. The ring connectors 10, 26, 29 are provided with flat receiving grooves 12 for accommodating carbon fiber rings 5. The width of the flat receiving grooves 12 is not less than the width of the carbon fiber cloth forming the carbon fiber rings 5.

[0085] Although carbon fiber has high tensile strength, its shear strength is very low. To prevent the carbon fiber ring 5 from weakening due to shear, the present invention provides a flat receiving groove 12 on the sling structure. The carbon fiber ring 5 is inserted into the flat receiving groove 12. This increases the force-bearing area of ​​the carbon fiber ring 5, converting shear force into pure tension. The structure is simple and easy to implement.

[0086] The present invention makes flexible carbon fiber cloth into lifting rings, which cooperate with the lifting device structure for lifting. The structure is simple, the lifting efficiency is high, and the cost is lower. It can also give full play to the advantage of the large bending rigidity of the steel rib prestressed concrete composite plate, reduce the deformation of the precast concrete base plate and the composite plate, and facilitate transportation and stacking.

[0087] The present invention does not limit the specific structural forms of the lifting ring connector 10 and the lifting rope connector 11. Three examples are given below.

[0088] Example 1:

[0089] like Figure 6-12 As shown, the lifting ring connector in this example is a pulley 10, and the sling connector is a hook 11. A circular groove formed around the pulley 10 serves as a flat receiving groove 12, the width of which is equal to the width of the carbon fiber cloth strip. The pulley 10 is arranged vertically, with a vertical plate 13 and 14 provided on either side of the pulley 10. Pin holes are provided at the bottom of the vertical plates 13 and 14 and at the center of the pulley 10. The lower portions of the two vertical plates 13 and 14 are connected to the pulley 10 via a horizontal pulley pin 15. The upper portions of the two vertical plates 13 and 14 are fixed together by an inter-plate connector 16, and the hook 11 is fixed to the inter-plate connector 16. The inter-plate connector 16 can be a bolt, and the hook 11 can be an ordinary steel hook, which can adapt to existing vertical lifting methods.

[0090] When in use, the carbon fiber lifting ring 5 is sleeved in the annular groove, and the lifting rope is connected to the hook 11 for lifting.

[0091] As an improvement to this example, Figure 8 As shown, one of the vertical plates 14 is a foldable structure, facilitating installation and removal of the carbon fiber hoist ring 5 and improving hoisting efficiency. It comprises an upper structure 17 and a lower structure 18, which are connected by a horizontal hinge pin 19, forming a hinge structure that allows the lower structure 18 to flip outward and upward. The folding point between the upper structure 17 and the lower structure 18 is higher than the highest point of the pulley 10.

[0092] As another improvement of this example, the pulley pin 15 is a cylindrical pin, one end of which is provided with a pin cap 20, and the other end of which is provided with a locking pin hole 21 perpendicular to the axial direction of the pulley pin 15.

[0093] The size of the pin cap 20 is larger than the diameter of the pulley pin 15 body. After the pulley pin 15 is inserted into the pin holes of the two vertical plates 13, 14 and the pulley 10, the pin cap 20 is close to the outer surface of a vertical plate 14, and a locking pin 22 is inserted into the locking pin hole 21 at the other end.

[0094] like Figure 9 As shown, the locking pin 22 is a cylindrical pin with an elastic locking ring 23 passing through its upper end. The diameter of the locking pin 22 is adapted to the diameter of the locking pin hole 21. The locking pin 22 is used to be vertically inserted from top to bottom into the locking pin hole 21 on the pulley pin 15. The distance between the position where the locking pin 22 passes through the elastic locking ring 23 and the bottom end of the locking pin 22 is greater than the maximum diameter of the elastic locking ring 23 in the free state. At this time, the elastic locking ring 23 is located outside the locking pin 22, that is, the elastic locking ring 23 in the free state cannot pass over the bottom of the locking pin 22, as shown in FIG. Figure 11 During installation, the elastic locking ring 23 needs to be placed on the pulley pin 15, and then the lower end of the elastic locking ring 23 needs to be moved over the lower end of the locking pin 22 so that it is located between the lower end of the locking pin 22 and the vertical plate 13, as shown. Figure 12 As shown in the figure, the maximum diameter of the elastic locking ring 23 in its free state is smaller than the distance between the position where the locking pin 22 is inserted and the bottom end of the locking pin 22. Therefore, the elastic locking ring 23 cannot freely pass over the bottom of the locking pin 22 and become loose, thus limiting and securing the locking pin 22. During removal, when force is applied to the elastic locking ring 23, the elastic locking ring 23 expands, allowing it to pass over the bottom of the locking pin 22 and be placed outside the locking pin 22, and then the locking pin 22 can be removed.

[0095] The top of the locking pin 22 can be provided with a pin cap, the size of which is larger than the diameter of the locking pin 22 body, to limit the locking pin 22 from falling downward; alternatively, the top of the locking pin 22 can also be provided with no pin cap, and the locking pin 22 can be limited from falling downward by an elastic locking ring 23.

[0096] To avoid loss, the pulley pin 15 (specifically, one end of the pulley pin with the pin cap 20) and the locking pin 22 (specifically, the upper end of the locking pin 22) can be connected to the two vertical plates 14 and 13 respectively through connecting ropes 24 and 25.

[0097] The elastic locking ring 23 can be flexibly selected according to needs, and any flexible material with elasticity can be used, for example, it can be an elastic metal ring structure, an elastic rope ring structure or a spring structure.

[0098] The working process of this example is as follows: when lifting, move the elastic locking ring 23 to the outside of the locking pin 22, pull out the locking pin 22, remove the pulley pin 15, flip the lower structure 18 of the foldable vertical plate 14 upward, and insert the carbon fiber ring 5 into the annular groove 12 of the pulley 10. After installing the carbon fiber ring 5, the foldable vertical plate 14 is reset in sequence, the pulley pin 15 and locking pin 22 are re-inserted, the elastic locking ring 23 is moved to the inside of the locking pin 22, and the hook 11 is hung on the vertical sling to start lifting. After the lifting is completed, the carbon fiber ring 5 can be removed using the same method.

[0099] Example 2:

[0100] like Figure 13-15 As shown, in this example, the eye connector is a shackle 26, and the sling connector is a bolt 27. The shackle 26 is a horseshoe-shaped shackle. The upper opening of the shackle 26 is provided with a connection hole, and the connection hole is provided with a thread, which is used to connect the two free ends of the upper part of the shackle 26 via the bolt 27. The upper opening of the shackle 26 is connected to the chain sling 28 via the bolt 27, forming a bolt-type bow shackle assembly that can adapt to existing vertical lifting methods. The bolt 27 is removable, which facilitates the disassembly and assembly of the carbon fiber eye 5 and the chain sling 28.

[0101] The lower part of the shackle 26 has a straight section, and the upper surface of the straight section is provided with a straight groove as a flat receiving groove 12. The straight groove is adapted to the carbon fiber ring 5, and the length of the straight groove is the same as the width of the carbon fiber cloth 5. The carbon fiber ring 5 is sleeved in the straight groove on the straight section of the shackle 26.

[0102] Before lifting, if Figure 14-15 As shown, rotate and remove the bolt 27, put the carbon fiber ring 5 on the shackle 26, and put it in the straight groove of the straight section at the bottom of the shackle 26. After installing the carbon fiber ring 5, put on the chain sling 28, reinstall the bolt 27, and start lifting. After the lifting is completed, remove the carbon fiber ring 5 in the opposite order of installation.

[0103] Example 3:

[0104] like Figure 16-18 As shown, the lifting ring connector of this example is a shackle 29, the sling connector is a hook 30, and the shackle 29 is a D-shaped shackle. The two free ends of the upper part of the shackle 29 are provided with pin holes for inserting a connecting pin 31. One end of the connecting pin 31 is inserted into the pin hole and fixed with a cotter pin 32. The hook 30 is fixed on the connecting pin 31 to prevent the hook 30 from slipping. The pin-type D-shaped shackle fixture composed of the shackle 29, the connecting pin 31, the cotter pin 32 and the hook 30. The hook 30 can be an ordinary steel hook, which can adapt to the existing vertical lifting method. The connecting pin 31 can be removed to facilitate the disassembly and assembly of the carbon fiber lifting ring 5.

[0105] The lower portion of the shackle 29 has a straight section, and the upper surface of the straight section is provided with a straight groove as a flat receiving groove 12.

[0106] Before lifting, if Figure 17-18 As shown, remove the cotter pin 32 and the connecting pin 31 in sequence, put the carbon fiber ring 5 on the shackle 29, and place it in the straight groove of the straight section at the bottom of the shackle 29. After installing the carbon fiber ring 5, replace the connecting pin 31 and the cotter pin 32, and start lifting. After the lifting is completed, remove the carbon fiber ring 5 in the opposite order of installation.

[0107] The present invention also provides a method for preparing the aforementioned prestressed concrete composite slab. The prestressed concrete composite slab is generally prepared in a factory and then transported to the construction site after preparation. If the construction site has the necessary preparation conditions, it can also be prepared on site. The preparation method includes:

[0108] S1: Obtain carbon fiber strips of required specifications, bend the carbon fiber strips into a ring-shaped carbon fiber ring 5, connect the lower end of the carbon fiber ring 5 to the steel structures 4 and 6, and make the upper part of the carbon fiber ring 5 extend upward to the top of the designed position of the concrete upper flange 3.

[0109] In this step, carbon fiber strips can be cut according to design requirements or directly produced into corresponding specifications, and then bent into carbon fiber rings 5. When connecting the carbon fiber rings 5 ​​to the steel structures 4 and 6, different connection methods are selected according to the different types of steel structures 4 and 6 (for example, steel ribs 4 or steel trusses 6).

[0110] S2: Set up the formwork for the upper concrete flange 3, tie the steel bars of the upper concrete flange 3, and use a film (such as a plastic film) to wrap at least the portion of the carbon fiber ring 5 that extends upward from the upper concrete flange 3 (the portion of the carbon fiber ring 5 that extends upward from the steel structure such as the steel rib 4 can also be completely wrapped).

[0111] Since the concrete upper flange 3 is made in reverse, before pouring concrete, the steel structures 4 and 6 need to be flipped 180 degrees and inverted at the designed position on the steel bars of the concrete upper flange 3, and the wrapped carbon fiber rings 5 ​​are placed vertically downward, and the excess part of the bottom of the carbon fiber rings 5 ​​is folded and laid flat on the bottom of the template of the concrete upper flange 3.

[0112] S3: After pouring the concrete upper flange 3 and curing it to the required strength, remove the formwork for the concrete upper flange 3. Turn the concrete upper flange 3 and the steel structures 4 and 6 180 degrees. Remove the film covering the carbon fiber eyelets 5, exposing the carbon fiber eyelets 5 to the concrete upper flange 3. A small amount of film poured inside the concrete upper flange 3 has little impact and can be removed without force.

[0113] S4: Setting the formwork of the prestressed concrete base plate 1, placing the transverse distribution steel bars of the prestressed concrete base plate 1, tensioning the prestressed steel bars placed on the transverse distribution steel bars, pouring the concrete of the prestressed concrete base plate 1 and curing it to the required strength before removing the formwork to obtain a prestressed concrete composite slab.

[0114] When the steel structure is a steel rib 4, in the aforementioned S1, the lower end of the carbon fiber ring 5 can be connected to the steel rib 4 in the following manner:

[0115] The first end of the carbon fiber cloth strip is directly adhered to the steel rib 4 through an adhesive, the carbon fiber cloth strip is bent into a ring, and the second end of the carbon fiber cloth strip is adhered to the first end through an adhesive.

[0116] Alternatively, the inner sides of both ends of the carbon fiber cloth strip are adhered to each other by adhesive to form a ring structure, and the outer side of one end of the carbon fiber cloth strip is adhered to the steel rib 4 by adhesive.

[0117] When the adhesive is epoxy resin adhesive or structural adhesive, it should be cured for at least 24 hours after bonding.

[0118] The present invention makes a flexible carbon fiber cloth into a hanging ring, and uses epoxy resin glue or structural glue to stick it on the steel rib, avoiding the need to tie steel bars. The invention is simple to make, has high production efficiency, and lowers the cost. It can give full play to the advantage of the high bending rigidity of the steel rib prestressed concrete composite plate, reduce the deformation of the precast concrete base plate and the composite plate, and facilitate transportation and stacking. At the same time, it can adapt to a variety of composite plates and has a wide range of applications.

[0119] An embodiment of the present invention further provides a method for hoisting the aforementioned prestressed concrete composite slab using the aforementioned hoisting structure, the method comprising:

[0120] S5: Connect the carbon fiber lifting ring to the lifting ring connector, and make the carbon fiber lifting ring be located in the flat receiving groove, and connect the sling connector to the sling.

[0121] When the sling structure is different, the operation method is also different. For details, please refer to the embodiment of the sling structure mentioned above, which will not be repeated here.

[0122] S6: The hoisting machinery uses the slings to lift the prestressed concrete composite slab to the designed construction location.

[0123] S7: After the hoisting is completed, the carbon fiber lifting ring is fitted to the upper flange of the concrete, the superimposed layer concrete is poured, and the carbon fiber lifting ring is buried in the superimposed layer concrete.

[0124] The present invention can be hoisted using either a steel hook or a shackle, fully utilizing the high tensile strength of carbon fiber and preventing shear damage to the carbon fiber rings. When pouring the composite layer concrete on site, the carbon fiber rings can be directly cast by fitting them to the upper flange of the concrete. No additional treatment is required, and the construction is not affected. There is no need to cut off the carbon fiber rings or pour a thicker concrete layer.

[0125] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A hanger structure for a prestressed concrete composite slab, characterized in that: The prestressed concrete composite slab includes a prestressed concrete bottom plate, on which at least one set of superstructures is arranged, each set of superstructures including a concrete upper flange, at least one steel structure and at least two carbon fiber suspension rings, wherein: The concrete upper flange is located at a set height above the prestressed concrete bottom plate, the steel structure is located between the prestressed concrete bottom plate and the concrete upper flange, and the lower end and upper end of the steel structure are cast in the prestressed concrete bottom plate and the concrete upper flange respectively; The carbon fiber hanging ring is an annular structure formed by a carbon fiber cloth strip of a certain width. The bottom end of the carbon fiber hanging ring is connected to the steel structure, and the upper part of the carbon fiber hanging ring extends upward from the top end of the concrete upper flange. The sling structure includes a lifting ring connector and a lifting cable connector, wherein the lifting cable connector is connected above the lifting ring connector, and the lifting ring connector is provided with a flat receiving groove for receiving the carbon fiber lifting ring, wherein the width of the flat receiving groove is not less than the width of the carbon fiber cloth forming the carbon fiber lifting ring; The lifting ring connector is a pulley, the lifting rope connector is a hook, and the annular groove formed on the pulley serves as the flat receiving groove; the pulley is vertically arranged, and a vertical plate is provided on each side of the pulley. The lower parts of the two vertical plates are connected to the pulley through a horizontal pulley pin, and the upper parts of the two vertical plates are fixed together through an inter-plate connector, and the hook is fixed to the inter-plate connector; One of the vertical plates includes an upper structure and a lower structure, wherein the upper structure and the lower structure are connected by a horizontal hinge pin, forming a hinge structure that allows the lower structure to flip outward and upward, and the folding point between the upper structure and the lower structure is higher than the highest point of the pulley; One end of the pulley pin is provided with a pin cap, and the other end is provided with a locking pin hole perpendicular to the axial direction of the pulley pin, a locking pin is inserted into the locking pin hole, the upper end of the locking pin is passed through an elastic locking ring, the elastic locking ring is sleeved on the pulley pin, and the lower end of the elastic locking ring sleeve is located between the lower end of the locking pin and the vertical plate, and the distance between the position where the locking pin passes through the elastic locking ring and the bottom end of the locking pin is greater than the maximum diameter of the elastic locking ring in a free state.

2. The hanger structure of the prestressed concrete composite slab according to claim 1, characterized in that: The steel structure is a steel rib, and the bottom end of the carbon fiber hanging ring is bonded to the steel rib by an adhesive.

3. The hanger structure of the prestressed concrete composite slab according to claim 2, characterized in that: The inner sides of both ends of the carbon fiber cloth strip are bonded together by adhesive, and the outer side of one end of the carbon fiber cloth strip is bonded to the steel rib by adhesive.

4. The hanger structure for prestressed concrete composite slab according to claim 3, characterized in that: The steel rib is a Z-shaped steel rib or a C-shaped steel rib, and the outer side of one end of the carbon fiber cloth strip is bonded to the side of the Z-shaped steel rib or the C-shaped steel rib that does not have an upper flange through an adhesive.

5. The hanger structure for prestressed concrete composite slab according to claim 3, characterized in that: The width of the carbon fiber cloth strip is 30-40 mm, and the bonding length between the carbon fiber cloth strip and the steel rib is not less than 30 mm.

6. The hanger structure for prestressed concrete composite slab according to claim 2, characterized in that: The steel structure is a steel truss, which includes an upper chord steel bar, a lower chord steel bar, and a web steel bar connecting the upper chord steel bar and the lower chord steel bar. The carbon fiber cloth strip passes from top to bottom through the arc-shaped transition structure sleeved on the upper chord steel bar, and then the two ends are bonded to form a carbon fiber ring.

7. The hanger structure for prestressed concrete composite slab according to claim 6, characterized in that: The inner side of one end of the carbon fiber cloth strip is bonded to the outer side of the other end.

8. The hanger structure for prestressed concrete composite slab according to any one of claims 2 to 7, characterized in that: The adhesive is epoxy resin glue or structural glue.

9. The hanger structure for prestressed concrete composite slab according to claim 8, characterized in that: The pulley pin and the locking pin are connected to the two vertical plates respectively through connecting ropes, and the elastic locking ring is an elastic metal ring or an elastic rope ring.

10. The hanger structure for prestressed concrete composite slab according to claim 2, characterized in that: The preparation method of the prestressed concrete composite slab comprises: S1: Obtain a carbon fiber strip of required specifications, bend the carbon fiber strip into a ring-shaped carbon fiber ring, connect the lower end of the carbon fiber ring to the steel structure, and make the upper part of the carbon fiber ring extend upward to the top of the designed position of the concrete upper flange; S2: Setting the formwork for the upper concrete flange, tying the steel bars of the upper concrete flange, wrapping at least the portion of the carbon fiber ring extending upward from the upper concrete flange with a film, turning the steel structure 180 degrees and placing it upside down at the designed position on the steel bars of the upper concrete flange, placing the wrapped carbon fiber ring vertically downward, and folding the bottom of the carbon fiber ring flat on the bottom of the formwork for the upper concrete flange; S3: After pouring the concrete upper flange and curing it to the required strength, remove the formwork of the concrete upper flange, turn the concrete upper flange and the steel structure 180 degrees, and remove the film wrapping the carbon fiber ring; S4: setting a formwork for the prestressed concrete bottom plate, placing transverse distribution steel bars of the prestressed concrete bottom plate, tensioning the prestressed steel bars placed on the transverse distribution steel bars, pouring concrete of the prestressed concrete bottom plate and curing it to the required strength before removing the formwork to obtain the prestressed concrete composite slab.

11. The hanger structure for prestressed concrete composite slab according to claim 10, characterized in that: When the steel structure is a steel rib, in S1, the lower end of the carbon fiber hanging ring is connected to the steel rib in the following manner: directly adhering a first end of the carbon fiber cloth strip to the steel rib with an adhesive, bending the carbon fiber cloth strip into a ring, and adhering a second end of the carbon fiber cloth strip to the first end with an adhesive; Alternatively, the inner sides of both ends of the carbon fiber cloth strip are adhered to each other by adhesive to form a ring structure, and the outer side of one end of the carbon fiber cloth strip is adhered to the steel rib by adhesive.

12. The hanger structure for prestressed concrete composite slab according to claim 11, characterized in that: When the adhesive is epoxy resin adhesive or structural adhesive, curing is performed for at least 24 hours after bonding.

13. A method for hoisting and constructing a prestressed concrete composite slab using the hoisting device structure of the prestressed concrete composite slab according to any one of claims 10 to 12, characterized in that: include: S5: Connecting the carbon fiber lifting ring to the lifting ring connector, and making the carbon fiber lifting ring be located in the flat receiving groove, and connecting the sling connector to the sling; S6: The hoisting machine hoists the prestressed concrete composite slab to the designed construction position through the sling; S7: After the hoisting is completed, the carbon fiber lifting ring is fitted to the upper flange of the concrete, the superimposed layer concrete is poured, and the carbon fiber lifting ring is buried in the superimposed layer concrete.

Images