A composite floor slab and a construction method thereof connected with a steel reinforced concrete beam

Abstract

The application discloses a composite floor slab and a construction method for connecting the composite floor slab with a steel reinforced concrete beam. Multiple letting grooves are formed on at least one side of a prefabricated slab, the letting grooves penetrate through two side surfaces and an end surface of the prefabricated slab, multiple bosses are formed at two ends of the prefabricated slab and are alternately distributed with the letting grooves, and a stress steel bar at the bottom of the slab is formed by extending from an end of the boss. The application sets multiple letting grooves at the ends of the composite floor slab, so that when the composite floor slab is installed, one end of the composite floor slab can avoid the obstruction of the stirrup, the one end can be inserted into the steel reinforced concrete beam more deeply, a certain distance is left for the mustache bar at the other end, the mustache bar can be smoothly lowered, the mustache bars at the two ends of the composite floor slab can be smoothly inserted into the steel reinforced concrete beam to a preset depth by reverse movement, the mustache bars do not need to be cut or bent, additional welding operation is not needed, and the construction efficiency and the overall anchoring are greatly improved.

Description

Technical Field

[0001] This invention relates to the field of construction, and more particularly to a composite floor slab and a construction method for its connection with a steel-concrete composite beam. Background Technology

[0002] Currently, with the increasing popularity of prefabricated buildings, composite floor slabs have been widely used. A typical composite floor slab consists of a precast slab with embedded bottom reinforcing bars and truss bars. The upper part of the truss bars extends above the precast slab to support the top reinforcing bars. After the composite layer is poured, the floor slab structure is formed. However, most composite floor slabs currently in widespread use still employ the traditional structure with reinforcing bars. The outward extension of these reinforcing bars results in the overall size of the composite floor slab being larger than the dimensions between the beams on both sides of the building's span. During construction, the reinforcing bars on both sides need to be inserted into the beams to a certain depth to ensure anchorage strength. Therefore, for beam reinforcement cages that have already been tied and fixed, it is difficult to smoothly install the composite slab between the two beams. To address this issue, in actual construction, the reinforcing bars are generally cut off, inserted into the composite slab, and then a short steel bar is welded to one end to ensure the anchorage length between the reinforcing bars and the beam. However, this method is inefficient and labor-intensive, and the added welded steel bars lack integrity with the original steel bars, making it difficult to guarantee strength and welding quality. Some methods involve lifting the entire bundled beam reinforcement cage, placing it into the composite slab, and then lowering the beam reinforcement cage. However, lifting the entire beam reinforcement cage is relatively easy for smaller or simpler structures with low self-weight. But for steel-concrete composite beams, the beam reinforcement cage contains both large steel beams and densely packed reinforcing bars. Moreover, such beams are also larger in size, generally 800mm-1400mm in height, and have a greater self-weight, making them difficult to lift and causing many inconveniences for the installation of the composite slab. Summary of the Invention

[0003] In view of the above-mentioned shortcomings of the existing technology, the purpose of this invention is to provide a construction method for composite floor slabs and their connection with steel-concrete beams, so as to solve the problem that the reinforcing bars cannot be smoothly inserted into the beams when installing composite floor slabs in existing buildings using steel-concrete beam structures.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A precast slab arranged horizontally and in a rectangular shape, and multiple truss reinforcements parallel to the sides of the precast slab. The lower part of the truss reinforcements is embedded in the precast slab, and the upper part protrudes from the surface of the precast slab. Bottom reinforcing bars are embedded in the precast slab, and the length direction of the bottom reinforcing bars is consistent with the length direction of the truss reinforcements. The bottom reinforcing bars are connected to the lower part of the truss reinforcements, and their two ends extend from both ends of the precast slab to form reinforcing bars. The invention is characterized in that multiple clearance grooves extending along the length direction of the bottom reinforcing bars are formed on at least one side of the precast slab. The clearance grooves penetrate both sides and the end faces of the precast slab, so that multiple bosses are formed at both ends of the precast slab, alternating with the clearance grooves. The bottom reinforcing bars extend from the ends of the bosses to form the reinforcing bars.

[0005] As an optimization, the clearance groove is an isosceles trapezoid, with the width of its opening side being greater than the width of the groove bottom. Correspondingly, the boss is an isosceles trapezoid with the top width being less than the bottom width.

[0006] As an optimization, the length of the truss reinforcement is less than the distance between the bottoms of the two opposite relief grooves at both ends of the precast slab.

[0007] As an optimization, a slope is provided on at least the upper side surface of the precast slab near both ends, so that the thickness of the precast slab gradually decreases along the direction near the end of the precast slab.

[0008] Based on the aforementioned composite floor slab, the present invention also provides a construction method for connecting the composite floor slab to a steel-concrete composite beam, comprising the following steps.

[0009] a) Install the first and second steel-concrete beams on opposite sides of the building bay;

[0010] Both the first and second steel-concrete composite beams include steel beams, and longitudinal steel bars and stirrups are tied around the perimeter of the steel beams to support the formwork. The longitudinal steel bars are spaced apart from the top surface of the steel beams.

[0011] b) Fabricate composite floor slabs;

[0012] When fabricating composite floor slabs, the spacing between the relief grooves should be adapted to the spacing between the stirrups on the periphery of the steel beam, and the thickness of the precast slab should be less than the spacing between the longitudinal reinforcement and the top surface of the steel beam.

[0013] c) Install composite floor slabs;

[0014] The composite floor slab is hoisted above the building bay, tilted at a certain angle, with its clearance groove aligned with the stirrups of the first steel-concrete beam. The reinforcing bars and protrusions at one end of the composite floor slab are inserted into the gap between the longitudinal reinforcement of the first steel-concrete beam and the top surface of the beam. During insertion, the stirrups enter the clearance groove until they abut against it. At the same time, the end of the reinforcing bar at the other end of the composite floor slab extends beyond the edge of the longitudinal reinforcement of the second steel-concrete beam. The composite floor slab is then laid flat and moved in the opposite direction, allowing the reinforcing bars at the other end to be inserted into the gap between the longitudinal reinforcement of the second steel-concrete beam and the top surface of the beam, until they reach a predetermined depth in both beams. The composite floor slab is then lowered, with both ends overlapping the formwork of the first and second steel-concrete beams.

[0015] d) Pouring concrete;

[0016] Concrete is poured into the formwork of the first and second steel-concrete beams and above the composite floor slab. After curing, the first and second steel-concrete beams and the composite floor slab form an integral whole.

[0017] As an optimization, multiple pins are distributed on the flange of the steel beam, and the spacing between adjacent pins along its length direction is adapted to the spacing between the stirrups, and the binding position of the stirrups corresponds to the position of the pins.

[0018] As an optimization, the template includes beam side template and beam bottom template. The beam side template near the composite floor slab includes vertical support plate and horizontal support plate, and diagonal bracing is provided between the vertical support plate and the horizontal support plate. The top surface of the horizontal support plate is flush with the bottom surface of the composite floor slab, and its width is greater than the depth of the clearance groove.

[0019] As an optimization, in step c, the preset depth is such that the end of the reinforcing bar extends beyond the center of the flange width of the steel beam.

[0020] Compared with the prior art, the present invention has the following advantages: By setting multiple clearance grooves at the ends of the composite floor slab, one end of the composite floor slab can avoid the obstruction of the stirrups during installation, allowing one end to be inserted deeper into the steel-concrete beam. This provides a certain distance for the reinforcing bars at the other end, enabling them to fall smoothly. By moving in the opposite direction, the reinforcing bars at both ends of the composite floor slab can be smoothly inserted into the pre-set extension of the steel-concrete beam without the need for cutting or bending the reinforcing bars or additional welding operations. This greatly improves construction efficiency and the overall integrity of the anchorage. At the same time, the protrusions formed by the clearance grooves allow the bottom reinforcing bars to pass through them, giving the protrusions good strength and providing good lap support for the composite floor slab. After the concrete is poured, the clearance grooves and the upper concrete form a more stable interlocking connection structure, which can better prevent cracking at the connection and improve the structural strength and stability. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the composite floor slab structure in this invention;

[0022] Figure 2 This is a schematic diagram of the main structure during the installation of the composite floor slab in this invention;

[0023] Figure 3 for Figure 2 Top view;

[0024] Figure 4 This is a schematic diagram of the overall structure of the floor slab and beams formed after the concrete is poured according to the present invention;

[0025] In the diagram: 1. Precast slab, 2. Truss reinforcement, 3. Beard reinforcement, 4. Relief groove, 5. Boss, 6. Slope, 7. Steel beam, 8. Longitudinal reinforcement, 9. Stirrup, 10. Dowel, 11. Beam side formwork, 12. Beam bottom formwork, 13. Vertical support plate, 14. Horizontal support plate, 15. Diagonal brace. Detailed Implementation

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to represent selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0028] It should be noted that similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figures, or the orientation or positional relationship commonly used when the product is in use. They are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance. In addition, the terms "horizontal," "vertical," etc., do not indicate that the component is required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted. In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0029] Example: See Figure 1 A composite floor slab includes a horizontally arranged rectangular precast slab 1 and multiple truss reinforcements 2 parallel to the sides of the precast slab 1. The lower part of the truss reinforcements 2 is embedded in the precast slab 1, and the upper part protrudes from the surface of the precast slab 1. Bottom reinforcing bars are embedded in the precast slab 1, and the length direction of the bottom reinforcing bars is consistent with the length direction of the truss reinforcements 2. The bottom reinforcing bars are connected to the lower part of the truss reinforcements 2, and their two ends extend from the two ends of the precast slab 1 to form reinforcing bars 3. The slab slab is characterized in that multiple relief grooves 4 extending along the length direction of the bottom reinforcing bars are opened on at least one side of the precast slab 1. The relief grooves 4 penetrate the two sides and the end face of the precast slab 1, so that multiple bosses 5 are formed at both ends of the precast slab 1, which are alternately distributed with the relief grooves 4. The bottom reinforcing bars extend from the ends of the bosses 5 to form the reinforcing bars 3.

[0030] Specifically, the clearance groove 4 is an isosceles trapezoid, with the width of its opening side greater than the width of the bottom. Correspondingly, the boss 5 is an isosceles trapezoid with a top width smaller than its bottom width. In this way, the boss 5 and the clearance groove 4 after the concrete is poured form a corbel-like structure, which improves its bending strength, thereby improving the connection strength with the upper composite layer and the steel-concrete beam, and improving the strength and stability of the floor slab.

[0031] The length of the truss reinforcement 2 is less than the distance between the bottoms of the two opposite relief grooves 4 at both ends of the precast slab 1. This is to prevent the truss reinforcement 2 from interfering with the longitudinal reinforcement 8 or stirrups 9 of the steel cage when the composite floor slab is inserted into the steel cage of the steel-concrete beam, so as to facilitate the smooth installation of the composite floor slab.

[0032] A slope 6 is provided on at least the upper side surface of the precast slab 1 near both ends, so that the thickness of the precast slab 1 gradually decreases along the direction near the end of the precast slab 1. In this way, by providing the slope 6, the composite floor slab can be smoothly inserted into the reinforcing cage by tilting at a certain angle. In addition, in order to ensure that the clearance groove 4 can give way to the required distance for the reinforcing bar 3 at the other end, the depth of the clearance groove 4 is greater than the length of the reinforcing bar 3.

[0033] Based on the aforementioned composite floor slab, the present invention also provides a construction method for connecting the composite floor slab to a steel-concrete composite beam, such as... Figures 2-4 As shown, it includes the following steps:

[0034] a) Install the first and second steel-concrete beams on opposite sides of the building bay;

[0035] Both the first and second steel-concrete composite beams include steel beams 7, with longitudinal reinforcing bars 8 and stirrups 9 tied around the perimeter of the steel beams 7 to support the formwork. The longitudinal reinforcing bars 8 are spaced apart from the top surface of the steel beams 7. Multiple pins 10 are distributed on the flanges of the steel beams 7. Specifically, two pins 10 are arranged as a group along the width of the flanges of the steel beams 7, and multiple groups are distributed along the length to improve the anchorage strength between the steel beams 7 and the concrete. The spacing between adjacent pins 10 along their length is adapted to the spacing between the stirrups 9, and the binding position of the stirrups 9 corresponds to the position of the pins 10. This ensures that sufficient space is formed between the stirrups 9 to accommodate the protrusions 5, allowing the protrusions 5 to be inserted smoothly without being obstructed by the pins 10 or stirrups 9, thus ensuring the smooth installation of the composite floor slab.

[0036] b) Fabricate composite floor slabs;

[0037] When fabricating composite floor slabs, the spacing between the clearance grooves 4 is adapted to the spacing between the stirrups 9 on the periphery of the steel beam 7, and the thickness of the precast slab 1 is made smaller than the spacing between the longitudinal reinforcement 8 and the top surface of the steel beam 7, so as to ensure that one end of the composite floor slab can be smoothly inserted into the spacing between the longitudinal reinforcement 8 and the top surface of the steel beam 7, and to make room for the required distance for the reinforcing bars 3 at the other end.

[0038] c) Install composite floor slabs;

[0039] The composite floor slab is hoisted above the building bay, tilted at a certain angle, with its clearance groove 4 aligned with the stirrup 9 of the first steel-concrete beam. The reinforcing bars 3 and protrusions 5 at one end of the composite floor slab are inserted into the gap between the longitudinal reinforcement 8 of the first steel-concrete beam and the top surface of the steel beam 7. During insertion, the stirrup 9 enters the clearance groove 4 until it abuts against it. At the same time, the end of the reinforcing bar 3 at the other end of the composite floor slab extends beyond the edge of the longitudinal reinforcement 8 of the second steel-concrete beam. The composite floor slab is then leveled and moved in the opposite direction, allowing the reinforcing bar 3 at the other end to insert into the gap between the longitudinal reinforcement 8 of the second steel-concrete beam and the top surface of the steel beam 7, until the reinforcing bar 3 is inserted to a predetermined depth in both beams. The preset depth is such that the end of the reinforcing bar 3 extends beyond the center of the flange width of the steel beam 7, that is, the length of the reinforcing bar 3 extending into the flange of the steel beam 7 needs to be greater than half. Then, the composite floor slab is lowered so that its two ends overlap the formwork of the first steel-concrete beam and the second steel-concrete beam respectively. Specifically, since the relief groove 4 is relatively deep, a formwork is needed at the bottom to seal the hole formed by the relief groove 4 to prevent grout leakage during pouring. Therefore, the formwork includes beam side formwork 11 and beam bottom formwork 12. The beam side formwork 11 near the composite floor slab includes a vertical support plate 13 and a horizontal support plate 14, and a diagonal brace 15 is provided between the vertical support plate 13 and the horizontal support plate 14. The top surface of the horizontal support plate 14 is flush with the bottom surface of the composite floor slab, and its width is greater than the depth of the relief groove 4.

[0040] d) Pouring concrete;

[0041] Concrete is poured into the formwork of the first and second steel-concrete beams and above the composite floor slab. After curing, the first and second steel-concrete beams and the composite floor slab form an integral whole.

[0042] This invention, by setting multiple clearance grooves at the ends of composite floor slabs, allows one end of the composite floor slab to avoid obstruction by stirrups during installation, enabling it to be inserted deeper into the steel-concrete beam. This provides sufficient space for the reinforcing bars at the other end, allowing them to fall smoothly. Through reverse movement, the reinforcing bars at both ends of the composite floor slab can be smoothly inserted into the pre-set extension of the steel-concrete beam, eliminating the need for cutting or bending the reinforcing bars or additional welding. This significantly improves construction efficiency and the overall integrity of the anchorage. Furthermore, the protrusions formed by the clearance grooves allow the bottom reinforcing bars to pass through, giving the protrusions good strength and providing excellent lap support for the composite floor slab. After concrete pouring, the clearance grooves form a more stable interlocking connection with the upper concrete layer, better preventing cracking at the connection and resulting in better structural strength and stability.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit the technical solutions. Those skilled in the art should understand that any modifications or equivalent substitutions to the technical solutions of the present invention without departing from the spirit and scope of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. A construction method for connecting composite floor slabs and steel-concrete composite beams, characterized in that: The composite floor slab includes a horizontally arranged rectangular precast slab and multiple truss reinforcements parallel to the sides of the precast slab. The lower part of the truss reinforcements is embedded in the precast slab, and the upper part protrudes from the surface of the precast slab. Bottom reinforcing bars are embedded in the precast slab, and the length direction of the bottom reinforcing bars is consistent with the length direction of the truss reinforcements. The bottom reinforcing bars are connected to the lower part of the truss reinforcements, and their two ends extend from the two ends of the precast slab to form burr bars. Multiple relief grooves extending along the length direction of the bottom reinforcing bars are opened on at least one side of the precast slab. The relief grooves penetrate both sides and the end face of the precast slab, so that multiple bosses are formed at both ends of the precast slab, which are alternately distributed with the relief grooves. The bottom reinforcing bars extend from the ends of the bosses to form the burr bars. Includes the following steps, a) Install the first and second steel-concrete beams on opposite sides of the building bay; Both the first and second steel-concrete composite beams include steel beams, and longitudinal steel bars and stirrups are tied around the perimeter of the steel beams to support the formwork. The longitudinal steel bars are spaced apart from the top surface of the steel beams. b) Fabricate composite floor slabs; When fabricating composite floor slabs, the spacing between the relief grooves should be adapted to the spacing between the stirrups on the periphery of the steel beam, and the thickness of the precast slab should be less than the spacing between the longitudinal reinforcement and the top surface of the steel beam. c) Install composite floor slabs; The composite floor slab is hoisted above the building bay, tilted at a certain angle, with its clearance groove aligned with the stirrups of the first steel-concrete beam. The reinforcing bars and protrusions at one end of the composite floor slab are inserted into the gap between the longitudinal reinforcement of the first steel-concrete beam and the top surface of the beam. During insertion, the stirrups enter the clearance groove until they abut against it. At the same time, the end of the reinforcing bar at the other end of the composite floor slab extends beyond the edge of the longitudinal reinforcement of the second steel-concrete beam. The composite floor slab is then laid flat and moved in the opposite direction, allowing the reinforcing bars at the other end to be inserted into the gap between the longitudinal reinforcement of the second steel-concrete beam and the top surface of the beam, until they reach a predetermined depth in both beams. The composite floor slab is then lowered, with both ends overlapping the formwork of the first and second steel-concrete beams. d) Pouring concrete; Concrete is poured into the formwork of the first and second steel-concrete beams and above the composite floor slab. After curing, the first and second steel-concrete beams and the composite floor slab form an integral whole.

2. The construction method for connecting composite floor slabs and steel-concrete composite beams according to claim 1, characterized in that: The clearance groove is an isosceles trapezoid, with the width of its opening side being greater than the width of the groove bottom. Correspondingly, the boss is an isosceles trapezoid with the top width being less than the bottom width.

3. The construction method for connecting composite floor slabs and steel-concrete composite beams according to claim 2, characterized in that: The length of the truss reinforcement is less than the distance between the bottoms of the two opposite relief grooves at both ends of the precast slab.

4. The construction method for connecting composite floor slabs and steel-concrete composite beams according to claim 2, characterized in that: The precast slab has a slope on at least the upper side surface near both ends, so that the thickness of the precast slab gradually decreases along the direction near the end of the precast slab.

5. The construction method for connecting composite floor slabs and steel-concrete composite beams according to claim 1, characterized in that: The steel beam has multiple pins distributed on its flange, and the spacing between adjacent pins along its length is adapted to the spacing between the stirrups, and the binding position of the stirrups corresponds to the position of the pins.

6. The construction method for connecting composite floor slabs and steel-concrete composite beams according to claim 1, characterized in that: The template includes beam side templates and beam bottom templates. The beam side templates near the composite floor slab include vertical support plates and horizontal support plates, and diagonal bracing is provided between the vertical support plates and the horizontal support plates. The top surface of the horizontal support plate is flush with the bottom surface of the composite floor slab, and its width is greater than the depth of the clearance groove.

7. The construction method for connecting composite floor slabs and steel-concrete composite beams according to claim 1, characterized in that: In step c, the preset depth is when the end of the reinforcing bar extends beyond the center of the flange width of the steel beam.

Images