Prestressed concrete steel bar truss laminated slab

Abstract

The utility model discloses a prestressed concrete steel bar truss composite board, including prefabricated prestressed bottom layer, steel bar truss layer and cast-in-situ composite layer, its characterized in that: the top fixed connection of prefabricated prestressed bottom layer has steel bar truss layer, and the outside of steel bar truss layer and located the top pouring of prefabricated prestressed bottom layer has cast-in-situ composite layer, and the main body of prefabricated prestressed bottom layer is high -strength concrete pouring board. The utility model discloses through the innovative configuration of six straight steel strands and steel strand ring combination structure of prestressed steel strand, can form bidirectional prestressed system when the prefabricated bottom board bears load, and steel strand ring effectively restricts concrete transverse deformation, and straight steel strand provides longitudinal pre -stress, and the synergistic effect makes the bottom board crack resistance improve, adopts micro -inflation concrete pouring composite layer and through interface agent and enhances interlayer adhesion, solved the technical problems that traditional composite board is easy to appear interlayer peeling under the action of temperature difference shrinkage.

Description

Technical Field

[0001] This utility model relates to the technical field of prestressed concrete reinforced steel truss composite slabs, specifically a prestressed concrete reinforced steel truss composite slab. Background Technology

[0002] Prestressed concrete reinforced truss composite slabs refer to a composite floor slab system that organically combines prestressing technology, reinforcing steel, and truss mesh with a composite slab structure. This component generates compressive stress against external loads by arranging prestressing tendons within the concrete slab, while using a steel truss or mesh as tension and shear bearing members. Both are bonded to the concrete through good adhesion or mechanical connection to form an integral load-bearing unit. Its main characteristics include the prestressing effect, spatial reinforcement of the steel truss, and interlayer cooperation within the composite slab, resulting in a slab with high load-bearing capacity, low deflection, and good crack resistance.

[0003] Traditional prestressed tendons are mostly arranged in a unidirectional straight line, which easily leads to stress concentration in the concrete slab under lateral force and a high prestress loss rate. Secondly, the connection between the steel truss and the precast base slab mostly relies on on-site binding, which has problems with poor positioning accuracy and insufficient node reliability, affecting the overall load-bearing performance. Furthermore, the interface delamination between the composite layer and the precast layer is prone to occur due to the difference in concrete shrinkage, and existing interface treatment processes cannot guarantee long-term collaborative performance. Finally, conventional reinforcement schemes cannot meet the stiffness requirements and structural lightweight requirements under large-span conditions. They often increase the reinforcement ratio to meet deflection restrictions, resulting in material waste and increased construction costs. Utility Model Content

[0004] The purpose of this utility model is to provide a prestressed concrete reinforced truss composite slab to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a prestressed concrete reinforced concrete truss composite slab, comprising a precast prestressed base slab, a reinforced concrete truss layer, and a cast-in-place composite layer, characterized in that: the reinforced concrete truss layer is fixedly connected to the top of the precast prestressed base slab; a cast-in-place composite layer is cast on the outer side of the reinforced concrete truss layer and on top of the precast prestressed base slab; the main body of the precast prestressed base slab is a high-strength concrete slab; and prestressed steel strands are pre-embedded inside the high-strength concrete slab.

[0006] As a further preferred embodiment of this technical solution, the steel truss layer includes a metal fixing plate, which is fixedly connected to the top of the high-strength concrete slab. Four lower chord steel bars are welded to the top of the metal fixing plate, and an upper chord steel bar is provided above the metal fixing plate and located between the two lower chord steel bars. Web reinforcement bars are welded between the two lower chord steel bars and the upper chord steel bars.

[0007] As a further preferred embodiment of this technical solution, the cast-in-place composite layer includes micro-expansion concrete, which is poured on top of the precast prestressed base slab layer and the steel truss layer.

[0008] As a further preferred embodiment of this technical solution, the prestressed steel strand consists of six straight steel strands and a steel strand ring. The straight steel strands and the steel strand ring are both pre-embedded inside the high-strength concrete slab, and the steel strand ring is welded to the outside of the six straight steel strands.

[0009] As a further preferred embodiment of this technical solution, the top of the micro-expansion concrete is brushed with an interface agent.

[0010] As a further preferred embodiment of this technical solution, the high-strength concrete slab is C40 or C50 type concrete, and the micro-expansion concrete is C30 type concrete.

[0011] This utility model provides a prestressed concrete reinforced truss composite slab, which has the following beneficial effects:

[0012] (1) This utility model innovatively configures the prestressed steel strands into a combination structure of six straight steel strands and steel strand rings, so that the precast base plate can form a two-way prestressed system when bearing load. The steel strand rings effectively constrain the lateral deformation of the concrete, and the straight steel strands provide longitudinal prestress. The synergistic effect of the two improves the crack resistance of the base plate. At the same time, the composite layer is cast with micro-expansion concrete and the interlayer bonding is enhanced by the interface agent, which solves the technical problem that traditional composite plates are prone to interlayer delamination under the action of temperature difference shrinkage.

[0013] (2) By optimizing the spatial structure of the steel truss layer, this utility model adopts a modular design of welding the lower chord steel bars and web bars with metal fixing plates to achieve precise positioning and overall improvement of the truss steel bars. The combined stress of the upper chord steel bars and the cast-in-place layer improves the stiffness of the component. The web bars are arranged at a 45° angle to effectively transmit shear force. With the strength gradient configuration of C50 high-strength concrete base plate and C30 micro-expansion concrete, the self-weight of the structure is reduced while ensuring the bearing capacity. This comprehensively solves the contradiction between deflection control and lightweight construction of large-span floor slabs. Attached Figure Description

[0014] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0015] Figure 2 This is a schematic diagram of the steel truss layer structure of this utility model;

[0016] Figure 3 This is a schematic diagram of the precast prestressed base slab structure of this utility model;

[0017] Figure 4This is a schematic diagram of the cast-in-place composite layer structure of this utility model;

[0018] In the diagram: 1. Precast prestressed base slab; 11. High-strength concrete slab; 12. Prestressed steel strand; 121. Straight steel strand; 122. Steel strand ring; 2. Reinforcing truss layer; 21. Metal fixing plate; 22. Bottom chord reinforcement; 23. Web reinforcement; 24. Top chord reinforcement; 3. Cast-in-place composite layer; 31. Micro-expansion concrete; 32. Interface agent. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0020] This utility model provides a technical solution: such as Figures 1-4 As shown, in this embodiment, a prestressed concrete reinforced concrete truss composite slab includes a precast prestressed base slab layer 1, a reinforced concrete truss layer 2, and a cast-in-place composite layer 3. The reinforced concrete truss layer 2 is fixedly connected to the top of the precast prestressed base slab layer 1. The cast-in-place composite layer 3 is cast on the outer side of the reinforced concrete truss layer 2 and on top of the precast prestressed base slab layer 1. The main body of the precast prestressed base slab layer 1 is a high-strength concrete slab 11, and prestressed steel strands 12 are pre-embedded inside the high-strength concrete slab 11. The reinforced concrete truss layer 2 includes a metal fixing plate 21, which is fixedly connected to the top of the high-strength concrete slab 11. Four lower chord steel bars 22 are welded to the top of 1. An upper chord steel bar 24 is provided above the metal fixing plate 21 and located at the two lower chord steel bars 22. A web bar 23 is welded between the two lower chord steel bars 22 and the upper chord steel bar 24. The cast-in-place composite layer 3 includes micro-expansion concrete 31. The micro-expansion concrete 31 is poured on the top of the precast prestressed base slab layer 1 and the steel truss layer 2. The prestressed steel strand 12 is composed of six straight steel strands 121 and steel strand rings 122. The straight steel strands 121 and steel strand rings 122 are both embedded in the interior of the high-strength concrete pouring slab 11. The steel strand rings 122 are welded to the outside of the six straight steel strands 121.

[0021] The precast prestressed base slab layer 1 is tensioned by prestressed steel strands 12, composed of six internally embedded straight steel strands 121 and an outer steel strand ring 122, before the high-strength concrete slab 11 hardens. After the concrete hardens, the tension is released to form prestress, effectively offsetting the tensile stress generated by external loads. The steel truss layer 2 is anchored to the precast layer by metal fixing plates 21. The three-dimensional truss system, composed of lower chord steel bars 22, upper chord steel bars 24, and web bars 23, transfers the load of the cast-in-place composite layer 3 to the precast layer, while enhancing the shear resistance of the interface. During cast-in-place construction, the micro-expansion concrete 31 generates moderate expansion force during hardening, forming a mechanical interlock with the steel truss layer 2, and achieving overall stress sharing with the precast layer through the coordinated deformation of the prestressed steel strands 12. This structure, through the combined action of the prestressed system, the truss force transmission mechanism, and the composite effect, ultimately forms a composite floor slab system with high crack resistance, high stiffness, and integrity.

[0022] like Figures 1-4 As shown, the top of the micro-expansion concrete 31 is brushed with an interface agent 32, the high-strength concrete pouring slab 11 is C40 or C50 type concrete, and the micro-expansion concrete 31 is C30 type concrete.

[0023] An interface agent 32 is pre-applied to the top of the micro-expansion concrete 31 (C30 type) to enhance its adhesion to the upper structural layer. Subsequently, a high-strength concrete slab 11 (using C40 or C50 type concrete) is poured on top. Through the transitional effect of the interface agent 32, the two different strength grades of concrete (C30 and C40 / C50) form a composite structural system that works synergistically. The expansion characteristics of the micro-expansion concrete 31 compensate for some of the shrinkage stress, while the high-strength concrete slab 11 provides the main load-bearing capacity. The combination of the two ensures structural strength while reducing the risk of interface cracking.

[0024] This utility model provides a prestressed concrete reinforced concrete truss composite slab, the specific working principle of which is as follows: The precast prestressed base slab layer 1 is a C40 or C50 high-strength concrete slab 11, with prestressed steel strands 12 composed of six straight steel strands 121 and steel strand rings 122 embedded inside. Prestress is established in the concrete through tensioning, which significantly improves the crack resistance of the base slab; The reinforced concrete truss layer 2 is anchored to the precast layer through a metal fixing plate 21. The three-dimensional truss system composed of the lower chord steel bars 22, the upper chord steel bars 24 and the web bars 23 efficiently transfers the load of the cast-in-place composite layer 3 to the precast layer, while enhancing the shear resistance of the composite surface; During the cast-in-place construction, an interface agent 32 is first applied to the top of the precast layer to strengthen the interlayer bond, and then C30 micro-expansion concrete 31 is poured. The expansion effect during its hardening process is used to offset the shrinkage stress, forming a mechanical interlock with the reinforced concrete truss and achieving overall stress through the synergistic deformation of the prestressed system. This structure utilizes a four-pronged mechanism of prestressed crack resistance, truss force transmission, interface strengthening, and expansion concrete to compensate for shrinkage, ultimately forming a composite floor system with high flexural stiffness, reliable interlayer bonding, and excellent durability.

[0025] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A prestressed concrete reinforced truss composite slab, comprising a precast prestressed base slab (1), a reinforced truss layer (2), and a cast-in-place composite layer (3), characterized in that: A steel truss layer (2) is fixedly connected to the top of the precast prestressed base slab layer (1). A cast-in-place composite layer (3) is poured on the outside of the steel truss layer (2) and on the top of the precast prestressed base slab layer (1). The main body of the precast prestressed base slab layer (1) is a high-strength concrete slab (11). Prestressed steel strands (12) are pre-embedded inside the high-strength concrete slab (11).

2. The prestressed concrete reinforced truss composite slab according to claim 1, characterized in that: The steel truss layer (2) includes a metal fixing plate (21), which is fixedly connected to the top of the high-strength concrete slab (11). Four lower chord steel bars (22) are welded to the top of the metal fixing plate (21). An upper chord steel bar (24) is provided above the metal fixing plate (21) and located between the two lower chord steel bars (22). A web bar (23) is welded between the two lower chord steel bars (22) and the upper chord steel bar (24).

3. The prestressed concrete reinforced truss composite slab according to claim 1, characterized in that: The cast-in-place composite layer (3) includes micro-expansion concrete (31), which is poured on top of the precast prestressed base slab layer (1) and the steel truss layer (2).

4. A prestressed concrete reinforced truss composite slab according to claim 1, characterized in that: The prestressed steel strand (12) is composed of six straight steel strands (121) and a steel strand ring (122). The straight steel strands (121) and the steel strand ring (122) are both embedded inside the high-strength concrete slab (11). The steel strand ring (122) is welded to the outside of the six straight steel strands (121).

5. A prestressed concrete reinforced truss composite slab according to claim 3, characterized in that: The top of the micro-expansion concrete (31) is brushed with an interface agent (32).

6. A prestressed concrete reinforced truss composite slab according to claim 3, characterized in that: The high-strength concrete slab (11) is C40 or C50 type concrete, and the micro-expansion concrete (31) is C30 type concrete.

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