Steel truss prefabricated concrete superposed beam

Abstract

The invention discloses a steel truss prefabricated concrete superposed beam which comprises a concrete thin plate, a steel web member, a steel upper chord, longitudinal load-bearing steel bars and stirrups. A plurality of longitudinal steel bars are arranged in the concrete thin plate; the stirrup part is anchored in the concrete thin plate; the steel web member is continuously bent; the steel upper chord is reliably connected with the wave crests of the steel web members to form a truss finished product; and wave troughs of the truss finished product piece are anchored in the concrete thin plate. The concrete thin plate and the steel web member truss are anchored to form the composite truss, so that light self weight, high rigidity and simple manufacturing of the member can be realized, industrial production of the member is realized, and the production efficiency of the member is improved.

Description

Technical Field

[0001] The present invention relates specifically to the field of engineering technology, and in particular to a steel truss precast concrete composite beam, which can be widely used in beams of various projects. Background Art

[0002] The existing technology prefabricated beams mostly use ordinary concrete composite beams, the prefabricated part of the concrete accounts for the majority, the composite part is in the compression zone, and the steel bars use ordinary steel bars. The existing technology composite beams are very heavy, the transportation cost is very high, and the requirements for on-site hoisting equipment are also particularly high. Moreover, the steel bars are all prefabricated in the composite beams, and the steel bars must be anchored in the columns, beams or shear walls. The steel bars of each component are very many in the staggered area, and it is easy to cause steel bar collision problems. Moreover, the steel bars use ordinary steel bars, and the steel bar strength utilization rate is low. The use of prestressed steel bars cannot meet the structural seismic requirements. The existing technology also uses steel tube truss prestressed composite beams, the bottom plate is made thinner, but the upper flange of the steel tube truss uses grouting technology, which is poured before the truss is installed. The steel pipe cannot be made larger, otherwise the truss has a large self-weight and is not easy to install in the steel cage. The beam’s own stiffness is weak, and the support spacing of the structure will be relatively large. Moreover, the upper flange of the steel tube truss is connected to the steel bar web by only one welding point, the acting load of the beam is large, and the safety of the component is not easy to be guaranteed. Summary of the invention

[0003] To this end, the present invention proposes a steel truss precast concrete composite beam to solve the problems raised in the above background technology.

[0004] To achieve the above purpose, the present invention discloses a steel truss precast concrete composite beam, which includes: a concrete sheet, a steel web, a steel upper chord, longitudinal stress-bearing steel bars, stirrups, and longitudinal stress-bearing steel bars of a cast-in-place layer. The concrete sheet is provided with a plurality of longitudinal steel bars; the bottom of the stirrups is anchored in the concrete sheet; the steel web is continuously bent by steel; the steel upper chord is a channel steel; the steel upper chord is fixedly connected with the steel web crest to form a truss finished part; the steel web trough of the truss finished part is anchored in the concrete sheet.

[0005] In the device of the present invention, the upper chord channel steel and the steel web member form a device, and a composite truss is formed by anchoring the precast concrete slab with the steel web member truss, wherein the concrete slab is the lower chord of the truss, the channel steel is the upper chord, and the continuously bent flat steel or channel steel is the web member. The steel web member and the upper chord channel steel are first pre-installed to form a truss finished product, and the truss finished product strengthens the concrete thin bottom plate to ensure the strength and rigidity of the bottom plate. When tying the stirrup reinforcement cage, the truss finished product is tied together with the stirrups. The stirrups, the longitudinal force-bearing steel bars and the truss are fixed together through the concrete bottom plate to form a steel bar skeleton of the beam, and the longitudinal steel bars can be used as the force-bearing steel bars of the precast component, and can also be used as the force-bearing steel bars after superposition. The processing amount of on-site steel bars is greatly reduced, and the steel bars can be completely processed in the workshop. Through the reinforcement of the truss, the rigidity of the concrete bottom plate can be strengthened, and the precast beam concrete slab can be made thin, light, simple to manufacture, and easy to realize the industrial standard production of components.

[0006] Furthermore, preferably, the steel web is a flat steel, and longitudinal concave and convex ribs are pressed on the web portion; and the steel upper chord is a channel steel.

[0007] Furthermore, preferably, the steel web is a channel steel, and the flange of the channel steel is cut or slit at the bends of the wave crests and the wave troughs; and the steel upper chord is a channel steel.

[0008] Further, preferably, the flange or web of the steel upper chord channel steel is pressed with notches or ribs.

[0009] Furthermore, preferably, a small hole is left on the flange of the steel upper chord channel steel, and a short steel bar or a bolt passes through the small hole.

[0010] Further, preferably, the small hole is located at the wave crest of the steel web.

[0011] Furthermore, preferably, the steel web has a straight section at the wave crest, and the length of the straight section is 30 mm to 100 mm.

[0012] Further, preferably, the steel upper chord channel steel opening faces upward.

[0013] Further, preferably, the width of the steel upper chord channel steel is smaller than that of the steel web member channel steel.

[0014] Furthermore, preferably, concrete, mortar or gypsum is poured into the steel upper chord channel steel.

[0015] Further, preferably, steel bars are laid in the steel upper chord.

[0016] Furthermore, preferably, prestressed steel bars are laid in the steel upper chord.

[0017] Further, preferably, the longitudinal reinforcement is located below the transverse short reinforcement or bolts.

[0018] Further, preferably, the stirrups are welded closed stirrups.

[0019] Furthermore, preferably, the longitudinal force-bearing steel bars are prestressed steel strands or a combination of partially prestressed steel strands and ordinary steel bars.

[0020] A steel truss precast concrete composite beam, characterized in that it comprises the following steps:

[0021] Step 1: Clean the mold platform and fix the side mold and end mold positions according to the component size;

[0022] Step 2: Place the stirrups;

[0023] Step 3: Cross the longitudinal stress-bearing steel bars and the finished truss parts;

[0024] Step 4: Fix the longitudinal stress-bearing steel bars, truss finished parts and stirrups;

[0025] Step 5: tensioning the prestressed steel strand;

[0026] Step 6: pouring concrete slab and upper chord channel steel;

[0027] Step 7: After the concrete reaches the tension strength, release the prestress and cut the longitudinal prestressed steel bars between the components;

[0028] Step 8: Lift the beams and store them in the factory yard.

[0029] The present invention adopts the above technology and has the following beneficial effects compared with the existing technology: In the device of the present invention, a new type of prestressed concrete prefabricated composite beam is formed by combining a concrete thin plate, a steel web, a steel upper chord, stirrups and longitudinal force-bearing steel bars. It is characterized by less prefabricated concrete, a thin bottom plate, and part of the longitudinal force-bearing steel bars prefabricated in the prefabricated layer. The bottom plate is reinforced by a channel steel truss, and the thickness of the bottom plate can be greatly reduced. The weight of the prefabricated component is relatively light, and the steel bar binding in the component is basically completed. Part of the steel bars are in the prefabricated layer, and the greatest common divisor of the longitudinal steel bars at the bottom of the project beam can be taken to achieve standardization of prefabricated components, which is more conducive to factory production. The remaining ordinary steel bars are paved on site, which is conducive to achieving steel bar avoidance, and is conducive to forming a ductile beam-column node and enhancing the seismic resistance of the structure. The present invention adopts channel steel as the upper chord, and the component installation is more convenient. When channel steel is used, the rigidity and strength of the prefabricated component can be more effectively improved. The channel steel can also be poured with concrete on it, and poured together with the bottom plate, so that the rigidity of the component is greater.

[0030] Flat steel is continuously bent to make the web, and longitudinal concave and convex ribs are pressed on the web part, which increases the turning radius of the flat steel and reduces the slenderness ratio, which is conducive to giving full play to the strength advantage of steel. The flat steel is kept flat at the peaks and troughs, and the peaks and troughs are easy to bend, and the steel does not need to be damaged at the bends. Flat steel is easier to mechanically form and easier to mechanize. Flat steel is wider, and the web can only be used in a single row to form a single-piece truss. The truss is more stable, more labor-saving and material-saving. Flat steel and upper chord channel steel are more convenient for connection and industrial production. Both are wide and flat, with a larger contact surface and more reliable connection.

[0031] Channel steel is used as the web member for continuous bending. Under the same cross-sectional area, the turning radius of the channel steel is larger and more stable, and the slenderness ratio is smaller, which is more conducive to giving full play to the strength advantage of steel. Channel steel is easier to mechanically form than steel pipes, and it is easier to achieve mechanized processing. The width of the channel steel is large, and the web member can only be used in a single row to form a single-piece truss. The truss is more stable and more labor-saving and material-saving. The web member of the channel steel is more convenient to connect and industrialize with the upper chord channel steel. Both are wide and flat, with a larger contact surface and a more reliable connection.

[0032] There is a straight section at the crest, which can increase the connection surface between the steel upper chord and the steel web. The connection between the two can be welded or bolted or rivet, which is convenient for the subsequent connection factory processing. The straight section is controlled at 30-100MM, which ensures the connection operation space and also ensures that the extension line of the centroid of the web intersects the lower chord. It is more conducive to forming an ideal truss model.

[0033] The upper chord of the channel steel is convenient for filling mortar and other fillers in the channel steel, and steel bars or prestressed steel bars can be placed in the fillers. It is beneficial to increase the strength and rigidity of the component and reduce the amount of steel used.

[0034] The stirrups are welded closed stirrups, which makes the components more convenient for factory processing and the shear resistance of the beams better.

[0035] Prefabricated longitudinal reinforcement uses prestressed steel strands and pre-tensioned steel bars instead of ordinary steel bars, which greatly saves steel usage. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a structural plan diagram of a steel truss precast concrete composite beam;

[0037] Figure 2 It is a structural elevation diagram of a steel truss precast concrete composite beam;

[0038] Figure 3 A perspective diagram of a structural facade steel skeleton of a steel truss precast concrete composite beam;

[0039] Figure 4It is a schematic diagram of the structural section of a steel truss precast concrete composite beam;

[0040] Figure 5 It is a schematic diagram of the structural section of a steel truss precast concrete composite beam;

[0041] Figure 6 It is a schematic diagram of a flat steel truss structure section of a steel truss precast concrete composite beam;

[0042] Figure 7 It is a schematic diagram of a flat steel pressing structure of a steel truss precast concrete composite beam;

[0043] Figure 8 The present invention is a schematic diagram of the cross-section of a channel steel truss structure of a steel truss precast concrete composite beam; in the figure: 1. concrete thin plate; 2. steel web member; 3. steel upper chord; 4. longitudinal steel bar; 5. stirrups; 6. longitudinal force-bearing steel bar of the cast-in-place layer; 8. small hole; 9. short transverse steel bar or bolt; 10. longitudinal steel bar. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] Example: Please refer to the attached Figure 1-8 The present invention provides a technical solution: a concrete slab, a steel web, a steel upper chord, longitudinal stress-bearing steel bars, stirrups, and longitudinal stress-bearing steel bars of a cast-in-place layer. The concrete slab is provided with a plurality of longitudinal steel bars; the bottom of the stirrups is anchored in the concrete slab; the steel web is continuously bent by steel bars or steel pipes or channel steels or flat steels; the steel upper chord is a channel steel or a steel bar; the steel upper chord is reliably connected with the steel web crest to form a truss finished product; the steel web trough of the truss finished product is anchored in the concrete slab.

[0046] In this embodiment, the steel web is made of flat steel, and the steel upper chord is made of channel steel. The two are combined together, and longitudinal concave and convex ribs are pressed on the web part, which increases the turning radius of the flat steel and reduces the slenderness ratio, which is conducive to giving full play to the strength advantage of steel. The flat steel is kept flat at the peaks and troughs, and the peaks and troughs are easy to bend, and the steel does not need to be damaged at the bends. Flat steel is easier to mechanically form and more easily mechanized. The flat steel is relatively wide, and the web can only be used in a single row to form a single-piece truss. The truss is more stable, more labor-saving and material-saving. The flat steel and the upper chord channel steel are more convenient to connect and industrially produce. Both are wide and flat, with a larger contact surface and a more reliable connection.

[0047] In this embodiment, channel steel is used as the web member and channel steel is used as the upper chord. The two are combined together, and the web member is continuously bent. Under the same cross-sectional area, the turning radius of the channel steel is larger and more stable, and the slenderness ratio is smaller, which is more conducive to giving full play to the strength advantage of steel. The mechanical forming of channel steel is easier than that of steel pipe, and it is easier to realize mechanized processing. The width of the channel steel is large, and the web member can be used in a single row to form a single-piece truss. The truss is more stable and more labor-saving and material-saving. The web member of the channel steel is more convenient to connect and industrially produce with the upper chord channel steel. Both are wide and flat, with a larger contact surface and a more reliable connection.

[0048] In this embodiment, the upper chord of the channel steel opens upward, which is convenient for manufacturing. When the channel steel opens upward, the web and the upper chord can be processed in the factory to form a prefabricated steel truss. Then it is installed on the concrete base plate, and the concrete in the channel steel and the base plate concrete can be poured at the same time. The prefabricated steel truss is light and easy for workers to install and position.

[0049] In this embodiment, the cold-pressed notches and patterns on the channel steel web bar or the channel steel web plate of the channel steel upper chord or the channel steel flange are beneficial to enhancing the rigidity and strength of the flange, and are also beneficial to enhancing the bonding force between the channel steel and concrete.

[0050] In this embodiment, a small hole is left on the flange of the upper chord channel steel, and a short steel bar or bolt is passed through the small hole. Since the connection between the upper chord of the channel steel and the concrete in the channel steel is weak, transverse steel bars or bolts are used for fixing. The transverse steel bars and bolts can effectively increase the shear strength of the channel steel and the concrete. At the same time, the transverse bolts can fix the channel steel to deform outward, which is more conducive to ensuring the adhesion between the channel steel and the concrete, and ensuring that the upper chord channel steel and the concrete in the channel steel work together. The longitudinal steel bars in the channel steel are located below the transverse short steel bars or bolts, which can enhance the grip of the longitudinal steel bars by the surrounding concrete.

[0051] In this embodiment, a straight section is used at the crest to increase the connection surface between the steel upper chord and the steel web. The connection between the two can be welded or bolted or rivet connected, which is convenient for the subsequent connection factory processing. The straight section is controlled at 30-100MM, which ensures the connection operation space and also ensures that the extension line of the centroid of the web intersects the lower chord. It is more conducive to forming an ideal truss model.

[0052] In this embodiment, the width of the upper chord of the channel steel is smaller than the width of the web of the channel steel, which is conducive to directly welding the flange of the web of the channel steel with the flange of the upper chord of the channel steel, resulting in greater connection strength, simpler force bearing and more convenient manufacturing.

[0053] In this embodiment, the upper chord of the channel steel is used to facilitate the filling of mortar and other fillers in the channel steel, and steel bars or prestressed steel bars can be placed in the fillers, which is beneficial to increase the strength and rigidity of the component and reduce the amount of steel used.

[0054] In this embodiment, the stirrups are welded closed stirrups, which makes the components more convenient for factory processing and has better shear resistance. After the stirrups are welded and closed, the shape of the stirrups is more stable, forming a closed frame. Compared with ordinary stirrups, welded closed stirrups are more convenient to fix using limit snaps, without wire binding, and save materials and labor in component processing. The mechanical properties of welded closed stirrups are better than those of open stirrups, and the number of mutual anchor hooks is reduced, saving the amount of steel bars.

[0055] Welded closed hoop, prefabricated part of the longitudinal reinforcement uses prestressed steel strands, using pre-tensioned prestressing to replace ordinary steel bars, greatly saving steel usage. Prestressed steel strands are relatively soft, making it easier to avoid steel bars during installation.

[0056] A steel truss precast concrete composite beam, characterized in that it comprises the following steps:

[0057] Step 1: Clean the mold platform and fix the side mold and end mold positions according to the component size;

[0058] Step 2: Place the stirrups;

[0059] Step 3: Cross the longitudinal stress-bearing steel bars and the finished truss parts;

[0060] Step 4: Fix the longitudinal stress-bearing steel bars, truss finished parts and stirrups;

[0061] Step 5: tensioning the prestressed steel strand;

[0062] Step 6: pouring concrete slab and upper chord channel steel;

[0063] Step 7: After the concrete reaches the tension strength, release the prestress and cut the longitudinal prestressed steel bars between the components;

[0064] Step 8: Lift the beams and store them in the factory yard

[0065] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A steel truss precast concrete composite beam, characterized in that: The invention comprises: a concrete sheet (1), a steel web member (2), a steel upper chord (3), and stirrups (5); a plurality of longitudinal force-bearing steel bars (4) are arranged in the concrete sheet (1); the bottom of the stirrups (5) is anchored in the concrete sheet (1); the steel web member (2) is formed by continuously bending steel; the steel upper chord (3) is a channel steel; the steel upper chord (3) and the wave crest of the steel web member (2) are fixedly connected together to form a truss finished part (7); the wave trough of the steel web member (2) of the truss finished part (7) is anchored in the concrete sheet (1).

2. The steel truss precast concrete composite beam according to claim 1, characterized in that: The steel web (2) is flat steel, and longitudinal concave and convex ribs are pressed on the web.

3. The steel truss precast concrete composite beam according to claim 1, characterized in that: The steel web member (2) is a channel steel, and the flange of the channel steel is cut or slit at the bends of the wave crest and the wave trough.

4. The steel truss precast concrete composite beam according to claim 1, characterized in that: The flange or web of the steel upper chord (3) channel steel is pressed with notches or ribs.

5. The steel truss precast concrete composite beam according to claim 1, characterized in that: A small hole (8) is left on the flange of the channel steel of the steel upper chord (3), and a short steel bar or a bolt (9) is passed through the small hole (8).

6. The steel truss precast concrete composite beam according to claim 5, characterized in that: The small hole (8) is located at the wave crest of the steel web (2).

7. The steel truss precast concrete composite beam according to claim 1, characterized in that: The steel web (2) has a straight section at the wave crest, and the length of the straight section is 30 mm to 100 mm.

8. The steel truss precast concrete composite beam according to claim 1, characterized in that: The steel upper chord (3) channel steel opening faces upward.

9. The steel truss precast concrete composite beam according to claim 3 and claim 8, characterized in that: The width of the steel upper chord (3) channel steel is smaller than that of the steel web member (2) channel steel.

10. The steel truss precast concrete composite beam according to claim 1, characterized in that: Concrete, mortar or plaster is poured into the channel steel of the steel upper chord (3).

11. The steel truss precast concrete composite beam according to claim 1, characterized in that: Longitudinal steel bars (10) are laid inside the steel upper chord (3).

12. The steel truss precast concrete composite beam according to claim 11, characterized in that: The longitudinal steel bars (10) are prestressed steel bars.

13. The steel truss precast concrete composite beam according to claim 5 and claim 11, characterized in that: The longitudinal reinforcement (10) is located below the transverse short reinforcement or bolt (9).

14. The steel truss precast concrete composite beam according to claim 1, characterized in that: The stirrups (5) are welded closed stirrups.

15. The steel truss precast concrete composite beam according to claim 1, characterized in that: The longitudinal stress-bearing steel bars (4) are prestressed steel strands or a combination of part of the prestressed steel strands and ordinary steel bars.

16. A method for manufacturing a steel truss precast concrete composite beam, characterized in that: It includes the following steps: Step 1: Clean the mold platform and fix the side mold and end mold positions according to the component size; Step 2: Arrange the stirrups (5); Step 3: Crossing the longitudinal stress-bearing steel bars (4) and the truss finished parts (7); Step 4: Fixing the longitudinal stress-bearing steel bars (4), the truss finished parts (7) and the stirrups (5); Step 5: Tensioning the prestressed steel strands (4) Step 6: pouring the concrete slab (1) and the upper chord channel steel; Step 7: After the concrete reaches the tension strength, release the prestress and cut the longitudinal prestressed steel bars between the components (4); Step 8: Lift the beams and store them in the factory yard.

Images