Composite beams composed of concrete of various strengths

Abstract

This utility model relates to the field of building construction technology, specifically to a composite beam composed of concrete of various strengths. It includes a precast beam body, concrete connecting blocks, and a composite surface layer. The precast beam body has slots for anchoring secondary beams. The concrete connecting blocks are fixed across these slots. The composite surface layer is cast on the upper part of the precast beam body and inside the slots. The concrete grade of the connecting blocks is no lower than that of the precast beam body, and the concrete grade of the composite surface layer is the same as that of the floor slab. This utility model solves the problems of beam cross-section variation at the junction of primary and secondary beams, insufficient load-bearing capacity during transportation and hoisting, and easy cracking affecting load-bearing performance by setting concrete connecting blocks at the slots.

Description

Technical Field

[0001] This utility model relates to the field of building construction technology, and in particular to a composite beam composed of concrete of various strengths. Background Technology

[0002] Existing composite main beam structures mainly exist in two forms: one is a complete beam structure. While this design ensures the integrity of the main beam, it makes it difficult to connect the secondary beams to the main beam, meaning the secondary beam reinforcement cannot be effectively anchored into the core area of ​​the main beam, violating the mandatory provisions of the "Code for Design of Concrete Structures" regarding the anchorage length of reinforcement at beam-column joints. The other is a slotted structure, where rectangular or trapezoidal slots are opened at the intersection of the main and secondary beams to accommodate the secondary beam reinforcement. However, the cross-sectional area of ​​the slotted area is significantly reduced (usually by 30%-50%), causing stress concentration. Actual measurement data shows that its flexural bearing capacity can decrease by more than 40%. More seriously, the concrete below the slot is prone to diagonal cracks due to sudden changes in stress. The expansion of these cracks further accelerates the corrosion of the reinforcement, creating a vicious cycle.

[0003] Therefore, there is an urgent need for a composite beam that balances the reliability of node connections with the overall structural performance to solve the above-mentioned technical problems. Utility Model Content

[0004] The main purpose of this utility model is to provide a composite beam composed of concrete of various strengths, which aims to solve the technical problem that existing composite main beam structures have rectangular or trapezoidal slots at the intersection of secondary beams, which makes the concrete below the slots prone to cracking due to sudden changes in stress.

[0005] To achieve the above objectives, this utility model proposes a composite beam composed of concrete of various strengths, comprising a precast beam body, concrete connecting blocks, and a composite surface layer. The precast beam body has a slot for anchoring secondary beams, the concrete connecting blocks are fixed across the slot, and the composite surface layer is poured on the upper part of the precast beam body and inside the slot. The concrete grade of the concrete connecting blocks is not lower than the concrete grade of the precast beam body, and the concrete grade of the composite surface layer is the same as the concrete grade of the floor slab.

[0006] The composite beam of this utility model, which is composed of concrete of various strengths, is further improved in that the concrete connecting block adopts a precast structure or a cast-in-place structure.

[0007] A further improvement of this utility model, which is a composite beam composed of concrete of various strengths, is that the length of the concrete connecting block is not less than the length of the groove.

[0008] A further improvement of this invention, which comprises a composite beam of various strengths of concrete, is that the concrete connecting block is disposed along the entire length of the precast beam.

[0009] A further improvement of this invention, which comprises a composite beam of various strengths of concrete, is that the width of the concrete connecting block is not greater than the width of the precast beam.

[0010] A further improvement of this invention, which comprises a composite beam of various strengths of concrete, is that the height of the concrete connecting block is not greater than the height of the precast beam.

[0011] The composite beam composed of concrete of various strengths is further improved in that the width of the concrete connecting block is smaller than the width of the precast beam, and the concrete connecting block is centrally or eccentrically positioned along the width direction of the precast beam.

[0012] The technical solution of this utility model has the following beneficial effects: This utility model presents a composite beam composed of concrete of various strengths. By setting concrete connecting blocks at the joints of the main and secondary beams, it solves the problems of beam cross-section variation at the joints, insufficient load-bearing capacity during transportation and hoisting, and easy cracking affecting the load-bearing performance. The precast beam body, concrete connecting blocks, and composite surface layer of this application all have different concrete strength grades, facilitating the utilization of the advantages of precast components and fully leveraging the beneficial effects of concrete strength grades on structural load-bearing capacity. The precast beam body uses high-strength concrete, providing the main shear bearing capacity and saving on stirrups in the beam. Higher-strength concrete is used at the joints to increase local compressive bearing capacity, reduce the cross-sectional area of ​​the connecting blocks at the joints, and minimize the adverse effects on the anchorage length of the secondary beam bottom reinforcement extending into the main beam. The concrete at the joints has the same strength grade as the composite panel concrete, facilitating construction. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the overall structure of the composite beam of this utility model, which is composed of concrete of various strengths. Figure 2 This is a schematic diagram of the structure of the composite beam composed of concrete of various strengths, after removing the composite surface layer. Figure 3 This is a side view of the composite beam of this utility model, which is composed of concrete of various strengths, after removing the composite surface layer; Figure 4 This is a top view of the composite beam of this utility model, which is composed of concrete of various strengths, after removing the composite surface layer; Figure 5 This is an overall side view of the composite beam of this utility model, which is composed of concrete of various strengths.

[0015] Explanation of icon numbers: 1. Precast beam; 2. Concrete connector; 3. Composite surface layer; 4. Stirrups; 5. Longitudinal reinforcement; 6. Groove. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0017] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0018] Furthermore, in this utility model, the use of terms such as "first," "second," etc., is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0019] In this utility model, unless otherwise explicitly specified and limited, the terms "connection," "fixing," etc., should be interpreted broadly. For example, "fixing" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0020] Furthermore, the technical solutions of the various embodiments of this utility model can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0021] like Figures 1-5As shown, this utility model proposes a composite beam composed of concrete of various strengths, including a precast beam body 1, a concrete connecting block 2, and a composite surface layer 3. The precast beam body 1 has a slot 6 for anchoring secondary beams. The concrete connecting block 2 is fixed across the slot 6. The composite surface layer 3 is poured into the upper part of the precast beam body 1 and inside the slot 6. The concrete grade of the concrete connecting block 2 is not lower than the concrete grade of the precast beam body 1, and the concrete grade of the composite surface layer 3 is the same as the concrete grade of the floor slab.

[0022] Specifically, such as Figure 5 As shown, the composite surface layer 3 is cast-in-place concrete. During pouring, the remaining empty spaces in the slot 6 are completely filled to form a complete composite beam. Figure 2 As shown, the precast beam 1 contains a reinforcing cage, which includes stirrups 4 and longitudinal bars 5. In this practical example, the precast beam 1 is precast using high-strength concrete (concrete grade C50~C80). When the precast beam 1 uses high-strength concrete of grade C60, the concrete connecting block 2 uses high-strength concrete of grade C70, and the composite surface layer 3 can use high-strength concrete of grade C65. By using concrete of different strengths for different parts, the advantages of precast beams can be fully utilized.

[0023] Preferably, the concrete connecting block 2 is a precast or cast-in-place structure. When a precast structure is used, it is precast before the precast beam 1. During the construction of the precast beam 1, the precast concrete connecting block 2 is fixed to the reinforcing cage of the precast beam 1, and then the concrete connecting block 2 is poured inside the precast beam 1. When a cast-in-place structure is used, a steel mold is reserved inside the reinforcing cage for the subsequent concrete connecting block 2. The concrete connecting block 2 is poured after the precast beam 1 is completed.

[0024] Specifically, the length of the concrete connecting block 2 is not less than the length of the slot 6, so as to ensure that the concrete connecting block 2 can span across the slot 6. The length of the concrete connecting block 2 can be adjusted according to actual needs to meet the stress requirements of precast beams 1 of different sizes.

[0025] Preferably, the concrete connecting block 2 is installed along the entire length of the precast beam 1, thereby improving the load-bearing capacity of the entire precast beam 1.

[0026] Specifically, the width of the concrete connecting block 2 is no greater than the width of the precast beam 1. During installation, the concrete connecting block 2 can be centered along the direction of the precast beam 1 or not.

[0027] Specifically, the height of the concrete connecting block 2 is not greater than the height of the precast beam 1.

[0028] Preferred, such as Figure 4As shown, the width of the concrete connecting block 2 is smaller than the width of the precast beam 1, and the concrete connecting block 2 is centered or eccentrically positioned along the width direction of the precast beam 1.

[0029] This utility model presents a composite beam composed of concrete of various strengths. By setting a concrete connecting block 2 at the slot 6, it solves the problems of beam cross-section variation at the slot 6 where the main and secondary beams intersect, insufficient load-bearing capacity during transportation and hoisting, and easy cracking affecting the load-bearing performance. The precast beam body 1, concrete connecting block 2, and composite surface layer 3 of this application all have different concrete strength grades, which facilitates the utilization of the advantages of precast components and makes full use of the beneficial effect of concrete strength grade on structural load-bearing capacity. The precast beam body 1 uses high-strength concrete to provide the main shear bearing capacity and saves on stirrups 4 in the beam. The slot 6 is set with higher-strength concrete to increase the local compressive bearing capacity, reduce the cross-sectional area of ​​the connecting block at the slot 6, and reduce the adverse effect on the anchorage length of the bottom reinforcement of the secondary beam extending into the main beam. The concrete at the slot 6 has the same strength grade as the concrete of the composite panel, which facilitates construction.

[0030] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A composite beam composed of concrete of various strengths, characterized in that, The precast beam (1), concrete connecting blocks (2), and composite surface layer (3) are provided. The precast beam (1) has a slot (6) for anchoring secondary beams. The concrete connecting blocks (2) are fixed across the slot (6). The composite surface layer (3) is poured on the upper part of the precast beam (1) and inside the slot (6). The concrete grade of the concrete connecting blocks (2) is not lower than the concrete grade of the precast beam (1). The concrete grade of the composite surface layer (3) is the same as the concrete grade of the floor slab.

2. The composite beam composed of concrete of various strengths as described in claim 1, characterized in that, The concrete connecting block (2) is a precast structure or a cast-in-place structure.

3. The composite beam composed of concrete of various strengths as described in claim 1, characterized in that, The length of the concrete connecting block (2) is not less than the length of the groove (6).

4. The composite beam composed of concrete of various strengths as described in claim 3, characterized in that, The concrete connecting block (2) is set throughout the precast beam (1).

5. The composite beam composed of concrete of various strengths as described in claim 1, characterized in that, The width of the concrete connecting block (2) is not greater than the width of the precast beam (1).

6. The composite beam composed of concrete of various strengths as described in claim 1, characterized in that, The height of the concrete connecting block (2) is not greater than the height of the precast beam (1).

7. The composite beam composed of concrete of various strengths as described in claim 5, characterized in that, The width of the concrete connecting block (2) is smaller than the width of the precast beam (1), and the concrete connecting block (2) is centered or eccentrically positioned along the width direction of the precast beam (1).

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