Prefabricated concrete composite ribbed beam laminated slab with shear keys

Abstract

The utility model discloses a precast concrete combined ribbed beam composite slab with shear keys, which comprises a precast concrete combined ribbed beam bottom plate with shear keys and a cast-in-place layer, the bottom plate comprises a bound reinforcing mesh, the shear keys and precast concrete combined ribbed beams, the shear keys and the precast concrete combined ribbed beams are arranged on the bound reinforcing mesh, the shear keys are bound and fixed on the reinforcing mesh through reinforcing steel binding wires, and the cast-in-place layer is arranged on the precast concrete combined ribbed beams. The middle of the prefabricated concrete combined ribbed beam is high, the two sides of the prefabricated concrete combined ribbed beam are low, the middle of the prefabricated concrete combined ribbed beam is made of UHPC, the two sides of the prefabricated concrete combined ribbed beam are made of common concrete, a prefabricated bottom plate concrete layer with a certain height is poured on the lower portion of the reinforcing mesh and the lower portion of the prefabricated concrete combined ribbed beam, the reinforcing mesh is placed on a bottom plate of the prefabricated concrete combined ribbed beam with the shear keys, and then a concrete entity is poured. The prefabricated bottom plate can be better matched with bending moment distribution, the bonding performance of new concrete and old concrete is enhanced, shear damage caused by earthquakes or dynamic loads is resisted, the anti-seismic performance is improved, the self weight of the prefabricated bottom plate is reduced, and the service life of a midspan key area is prolonged.

Description

Technical Field

[0001] This utility model belongs to the field of building engineering technology, specifically relating to a precast concrete composite ribbed slab with shear keys. Background Technology

[0002] Prefabricated concrete structures have advantages such as fast construction speed, energy saving and environmental protection, and low labor demand, and have developed rapidly in China in recent years. Currently, the composite floor slabs widely used in prefabricated concrete structure projects are reinforced concrete truss composite slabs. This type of composite slab has better overall integrity than fully precast slabs and saves on formwork compared to cast-in-place slabs. However, in engineering applications, it has been found that reinforced concrete composite slabs have limited load-bearing capacity, require significant support during construction, and have durability issues, which to some extent restrict the application and promotion of reinforced concrete composite slabs.

[0003] To address the aforementioned issues, a precast concrete composite ribbed slab structure with shear keys is proposed. Specifically, this slab involves placing precast concrete composite ribbed beams and shear keys on a pre-tied horizontal steel mesh, then casting them together with the mesh to form a precast base slab in the form of precast concrete composite ribbed beams with shear keys. The ribbed beams of this precast concrete composite ribbed slab with shear keys have a cross-section that is higher in the middle and lower at both ends. The middle section bears a larger bending moment, utilizing the high strength of UHPC (Ultra-High-Pressure Polymer) to fully leverage its advantages, while the two ends use ordinary concrete. This approach satisfies the load-bearing requirements while optimizing the stress performance and achieving rational material utilization. Summary of the Invention

[0004] The purpose of this utility model is to provide a precast concrete composite ribbed slab with shear keys, which can better match the bending moment distribution, enhance the bonding performance between new and old concrete, resist shear failure under earthquakes or dynamic loads, improve seismic performance, reduce the self-weight of the precast base slab, and extend the service life of key areas in the mid-span.

[0005] This utility model provides the following technical solution: a precast concrete composite ribbed slab with shear keys, comprising longitudinal reinforcement of the bottom slab, transverse reinforcement of the bottom slab, precast concrete composite ribbed beams, shear keys, longitudinal reinforcement of the bottom side of the ribbed beams, through reinforcement of the top side of the ribbed beams, transverse anchoring reinforcement, a precast bottom slab concrete layer, a steel mesh on the upper part of the composite slab, and a cast-in-place concrete layer on the upper part of the composite slab.

[0006] The longitudinal and transverse reinforcing bars of the base slab are tied together with reinforcing wire to form a horizontal reinforcing mesh; the precast concrete composite rib beam is set on the horizontal reinforcing mesh, the shear key is placed at both ends of the horizontal reinforcing mesh, and the shear key is placed on both sides of the precast concrete composite rib beam. The horizontal reinforcing mesh, the lower part of the precast concrete composite rib beam, and the lower part of the shear key are filled with concrete of a certain thickness to form a precast base slab concrete layer.

[0007] The precast concrete composite rib beam is higher in the middle and lower on both sides. The middle part is made of UHPC and the two sides are made of ordinary concrete. A through-beam is set on the top side of the precast concrete composite rib beam, and two longitudinal top-beam reinforcement bars are set on the bottom side of the precast concrete composite rib beam. Transverse anchor bars are set on the longitudinal top-beam reinforcement bars. The longitudinal bottom-beam reinforcement bars and the transverse anchor bars are tied and fixed by reinforcement wire. The through-beam reinforcement bars on the bottom side of the rib beam extend a certain length from each end face of the precast concrete composite rib beam, and the transverse anchor bars extend a certain length from each side of the outer facade of the precast concrete composite rib beam.

[0008] The precast base slab concrete layer is used to place the upper steel mesh of the composite slab, and the upper cast-in-place concrete layer of the composite slab is then poured.

[0009] Preferably, the longitudinal length of the precast concrete composite rib beam does not exceed the length of the precast base slab concrete layer.

[0010] Preferably, the length of the longitudinal reinforcement on the bottom side and the through reinforcement on the top side of the precast concrete composite rib beam exceed the length of the precast concrete composite rib beam, and both ends do not exceed the edge of the precast bottom slab concrete layer.

[0011] Preferably, the middle 1 / 5 of the precast concrete composite rib beam is made of UHPC, and the remaining part is made of ordinary concrete.

[0012] Preferably, the highest point of the precast concrete composite rib beam decreases sequentially towards both sides at 1 / 2, with the vertical difference between the highest point and the edges at both ends being approximately 20~30mm.

[0013] Preferably, the shear key is spaced approximately 30-50 mm from the edges of both ends of the precast concrete base slab.

[0014] The beneficial effects of this utility model are as follows: The precast concrete composite ribbed beam base slab with shear keys is equipped with precast concrete composite ribbed beams, shear keys, and steel mesh. The precast concrete composite ribbed beams adopt a cross-sectional shape that is higher in the middle and lower on both sides, which can better match the bending moment distribution, reduce the self-weight of the precast base slab, and extend the service life of the critical area in the mid-span. The shear keys enhance the bonding performance between new and old concrete, resist shear failure under earthquakes or dynamic loads, and improve seismic performance. By precisely matching the material properties with the stress requirements, a unity of safety, economy, and efficiency is achieved. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model;

[0016] Figure 2 This is a schematic diagram of the base plate structure of this utility model;

[0017] Figure 3 This is a schematic diagram of a precast concrete ribbed beam.

[0018] Figure 4 This is a cross-sectional view of the present invention.

[0019] In the figure, 1-longitudinal reinforcement of the bottom slab; 2-transverse reinforcement of the bottom slab; 3-precast concrete composite rib beam; 4-shear key; 5-longitudinal reinforcement at the bottom of the rib beam; 6-through reinforcement at the top of the rib beam; 7-transverse anchorage reinforcement; 8-precast bottom slab concrete layer; 9-upper reinforcement mesh of the composite slab; 10-upper cast-in-place concrete layer of the composite slab. Detailed Implementation

[0020] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings.

[0021] like Figure 1-4 As shown, a precast concrete composite ribbed slab with shear keys includes longitudinal reinforcement 1 of the bottom slab, transverse reinforcement 2 of the bottom slab, precast concrete composite ribbed beam 3, shear key 4, longitudinal reinforcement 5 of the bottom side of the ribbed beam, through reinforcement 6 of the top side of the ribbed beam, transverse anchoring reinforcement 7, precast bottom slab concrete layer 8, upper reinforcement mesh of the composite slab 9, and upper cast-in-place concrete layer of the composite slab 10.

[0022] The longitudinal reinforcement 1 and the transverse reinforcement 2 of the bottom slab are tied together with steel wire to form a horizontal steel mesh; the precast concrete composite rib beam 3 is set on the horizontal steel mesh, the shear key 4 is placed at both ends of the horizontal steel mesh, and the shear key 4 is placed on both sides of the precast concrete composite rib beam 3. The horizontal steel mesh, the lower part of the precast concrete composite rib beam 3, and the lower part of the shear key 4 are filled with concrete of a certain thickness to form a precast bottom slab concrete layer 8.

[0023] The precast concrete composite rib beam 3 is higher in the middle and lower on both sides, with the middle part using UHPC and the two sides using ordinary concrete. A top-side through-bar 6 is provided on the top side of the precast concrete composite rib beam 3, and two bottom-side longitudinal bars 5 are provided on the bottom side. A transverse anchor bar 7 is provided on the bottom-side longitudinal bars 5. The bottom-side longitudinal bars 5 and the transverse anchor bars 7 are tied and fixed by steel wire. The bottom-side longitudinal bars 5 and the top-side through-bar 6 extend beyond each end face of the precast concrete composite rib beam 3 by a certain length, and the transverse anchor bars 7 extend beyond each side of the outer facade of the precast concrete composite rib beam 3 by a certain length.

[0024] The longitudinal length of the precast concrete composite rib beam 3 does not exceed the length of the precast base slab concrete layer 8. The lengths of the bottom longitudinal reinforcement 5 and the top through reinforcement 6 of the rib beam exceed the length of the precast concrete composite rib beam 3, and both ends do not exceed the edges of the precast base slab concrete layer 8. The middle 1 / 5 of the precast concrete composite rib beam 3 is made of UHPC, and the remaining part is made of ordinary concrete. The maximum height of the precast concrete composite rib beam 3 decreases progressively towards both sides at the 1 / 2 mark, with the vertical difference between the highest point and the edges of both ends being approximately 20-30 mm. The shear key 4 is approximately 30-50 mm from the edges of both ends of the precast base slab concrete layer.

[0025] The precast base slab concrete layer 8 is placed with the upper steel mesh 9 of the composite slab, and the upper cast-in-place concrete layer 10 of the composite slab is poured.

[0026] A method for manufacturing a precast concrete composite ribbed slab with shear keys includes the following steps:

[0027] Step 1: Install the mold for casting the precast concrete composite rib beam on the mold platform and apply a release agent.

[0028] Step 2: Place the longitudinal steel bars on the bottom side of the precast concrete composite rib beam and the through steel bars on the top side of the precast concrete composite rib beam, which have been processed according to the design dimensions, into the mold for casting the precast concrete composite rib beam.

[0029] Step 3: Tie the transverse anchoring steel bars of the precast concrete rib beam, which has been processed according to the design dimensions, to the longitudinal steel bars on the bottom side of the rib beam using steel bar ties.

[0030] Step 4: Pour the ordinary concrete portion and vibrate it. When it is about to set, roughen the surface and pour the UHPC to make a precast concrete composite rib beam. Before the concrete sets, roughen the surface of the UHPC portion.

[0031] Step 5: Demold the concrete when it reaches the required strength for demolding and hoisting.

[0032] Step 6: Install the mold for casting the precast base plate on the mold platform and apply a release agent.

[0033] Step 7: Tie the transverse and longitudinal reinforcing bars of the precast base slab in the precast base slab mold by manually tying the reinforcing bars, with the transverse reinforcing bars on top and the longitudinal reinforcing bars on the bottom.

[0034] Step 8: Hoist the demolded precast concrete rib beams to the top of the precast base plate mold and place them on the corresponding horizontal reinforcing bars of the base plate.

[0035] Step 9: Place the shear key on the reinforcing mesh and fix it by manually tying the reinforcing bars;

[0036] Step 10: Pour the precast base slab concrete layer and vibrate it to form a precast base slab. The upper surface of the precast base slab should be roughened before the concrete sets.

[0037] Step 11: Once the concrete has reached the required strength for demolding, demold it and transport it outside the production workshop for further curing.

[0038] Step 12: Place the upper steel mesh of the composite slab on the bottom slab of the precast concrete composite rib beam with shear keys, then pour the upper cast-in-place concrete layer of the composite slab and vibrate it to form the composite slab structure. The upper surface of the composite slab should be smoothed.

[0039] The specific embodiments described above further illustrate the purpose and technical solution of this utility model. It should be understood that the above description is only a specific embodiment of this utility model and is not intended to limit the protection scope of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A precast concrete composite ribbed slab with shear keys, characterized in that: This includes longitudinal reinforcement of the bottom slab, transverse reinforcement of the bottom slab, precast concrete composite rib beams, shear keys, longitudinal reinforcement on the bottom side of the rib beams, through reinforcement on the top side of the rib beams, transverse anchorage reinforcement, precast bottom slab concrete layer, upper steel mesh of the composite slab, and upper cast-in-place concrete layer of the composite slab. The longitudinal and transverse reinforcing bars of the bottom slab are tied together with reinforcing wire to form a horizontal reinforcing mesh; the precast concrete composite rib beam is set on the horizontal reinforcing mesh, the shear key is placed at both ends of the horizontal reinforcing mesh, and the shear key is placed on both sides of the precast concrete composite rib beam. The horizontal reinforcing mesh, the lower part of the precast concrete composite rib beam, and the lower part of the shear key are filled with concrete to form a precast bottom slab concrete layer. The precast concrete composite rib beam is higher in the middle and lower on both sides. The middle part is made of UHPC and the two sides are made of ordinary concrete. A through-beam is set on the top side of the precast concrete composite rib beam, and two longitudinal top-beam reinforcement bars are set on the bottom side of the precast concrete composite rib beam. Transverse anchor bars are set on the longitudinal top-beam reinforcement bars. The longitudinal bottom-beam reinforcement bars and the transverse anchor bars are tied and fixed by reinforcement wire. The through-beam reinforcement bars on the bottom side of the rib beam extend a certain length from each end face of the precast concrete composite rib beam, and the transverse anchor bars extend a certain length from each side of the outer facade of the precast concrete composite rib beam. The precast base slab concrete layer is used to place the upper steel mesh of the composite slab, and the upper cast-in-place concrete layer of the composite slab is then poured.

2. The precast concrete composite ribbed slab with shear keys according to claim 1, characterized in that: The longitudinal length of the precast concrete composite rib beam shall not exceed the length of the precast base slab concrete layer.

3. A precast concrete composite ribbed slab with shear keys according to claim 2, characterized in that: The length of the bottom longitudinal reinforcement and the top through reinforcement of the precast concrete composite rib beam exceed the length of the precast concrete composite rib beam, and both ends do not exceed the edge of the precast bottom slab concrete layer.

4. A precast concrete composite ribbed slab with shear keys according to claim 3, characterized in that: The middle 1 / 5 of the precast concrete composite rib beam is made of UHPC, and the remaining part is made of ordinary concrete.

5. A precast concrete composite ribbed slab with shear keys according to claim 4, characterized in that: The highest point of the precast concrete composite rib beam decreases progressively towards both sides at the 1 / 2 mark, with the vertical difference between the highest point and the edges at both ends being 20-30mm.

6. A precast concrete composite ribbed slab with shear keys according to claim 5, characterized in that: The shear key is 30-50 mm from both ends of the precast base slab concrete layer.

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