Truss steel bar two-way laminated slab separation type joint structure and construction method thereof

Abstract

The invention discloses a truss steel bar two-way laminated slab separating type joint structure and a construction method. The truss steel bar two-way laminated slab separating type joint structure comprises a plurality of prefabricated laminated slabs and a cast-in-place layer. The plurality of prefabricated laminated slabs are adjacently arranged, and a separated joint is reserved between every two adjacent prefabricated laminated slabs; the adjacent plate sides of the prefabricated laminated plates are provided with upper chamfers, lower chamfers and parallel middle side faces respectively, a lower chamfer inclined joint is formed between the lower chamfers of every two adjacent prefabricated laminated plates, a flat joint is formed between the middle side faces of every two adjacent prefabricated laminated plates, and an upper opening is formed between the upper chamfers. The cast-in-place layer is cast above the prefabricated laminated slabs and between the upper openings of the two adjacent prefabricated laminated slabs; the prefabricated laminated slab and the cast-in-place layer are internally provided with distributed steel bars perpendicular to the slab side direction and load-bearing steel bars perpendicular to the slab end direction, the distributed steel bars perpendicular to the slab side direction are not exposed, and the exposed steel bars are the load-bearing steel bars perpendicular to the slab end direction in the prefabricated laminated slab. According to the invention, the production and installation difficulty of the laminated slab is effectively reduced, the formwork erection at the joint position is reduced, and the potential quality hazards such as cracking and slab staggering at the joint position are eliminated.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fabricated concrete structure, in particular to a truss reinforced bidirectional composite slab split joint structure and a construction method thereof. BACKGROUND

[0002] With the continuous development and promotion of building industrialization, the truss reinforced concrete composite slab is increasingly widely used in fabricated buildings due to its high design standardization, good prefabricated product quality, high production efficiency, fast construction speed, and the ability to save a large amount of scaffolding and formwork.

[0003] After the truss reinforced concrete composite slab is prefabricated in the factory, it needs to be transported over a long distance to the construction site for hoisting. Due to the limitations of transport vehicles and road conditions, the floor slabs of living rooms, bedrooms and other areas are usually split into a plurality of composite slab units with smaller sizes for transportation. This approach inevitably introduces joints between the composite slabs. The quality of joint construction directly affects the overall construction quality and performance of the composite floor slabs. High-quality joint construction can effectively transfer the internal forces between the slabs, so that the multiple composite slabs achieve the effect of overall force.

[0004] The composite slab can be designed as a unidirectional slab or a bidirectional slab according to the joint structure, support conditions and length-width ratio. The Technical Specification for Fabricated Concrete Structures (JGJ 1-2014) specifies two types of composite slab joints: integral joints and split joints.

[0005] The integral joint achieves moment transfer through the continuous extension of steel bars, forming a bidirectional force system for the floor slab. This structure requires steel bars to be extended from all four edges of the composite slab, which not only increases the production difficulty during the prefabrication stage, but also brings challenges during the hoisting at the site: the steel bars at the ends of the slab need to be avoided from colliding with the steel bars of the cast-in-place walls, columns and beams during construction, and the mutual interference of the extended steel bars between adjacent composite slabs needs to be handled, significantly increasing the construction complexity. In addition, in order to achieve effective transfer of steel stress, the steel bars extended from the sides of adjacent slabs need to have a certain lap length, which requires the width of the integral joint to be not less than 200mm. A wider joint often requires formwork to be set up for pouring. If there is a large deviation in the installation of the composite slab or the setup of the bottom formwork, or multiple deviations are superimposed, it is easy to cause the cast-in-place concrete at the joint to be misaligned with the surface of the prefabricated slab, which needs to be polished and repaired subsequently.

[0006] In the split joint method, the steel bars are not extended from the sides of the composite slab, which facilitates the production and installation of the components and effectively reduces the workload of setting up formwork at the joint, and only the bottom chamfer of the composite slab needs to be filled and treated subsequently.

[0007] The laminated slab with the separated joint is calculated according to the one-way stress state. The additional structure lap joint steel bars are arranged on the prefabricated slab surface of the joint, and the steel bars only play a role in crack resistance, and the bending moment and shear force are not considered. Due to the weak rigidity and large deflection of the one-way stress slab, if the joint of the slab is not properly handled, cracks are prone to occur at the joint position. SUMMARY

[0008] The purpose of the present application is to provide a truss steel bar bidirectional laminated slab separated joint structure and a construction method thereof, which reduces the production and installation difficulty of the laminated slab, reduces the formwork setting of the joint position, and eliminates the quality hidden dangers such as cracking and dislocation at the joint.

[0009] To achieve the above-mentioned purpose, the technical scheme provided by the present application is:

[0010] The first aspect of the present application provides a truss steel bar bidirectional laminated slab separated joint structure, comprising a plurality of prefabricated laminated slabs and a cast-in-place layer; the plurality of prefabricated laminated slabs are arranged adjacent to each other, and a separated joint is left between the two adjacent prefabricated laminated slabs;

[0011] The adjacent slab sides of the prefabricated laminated slab have an upper chamfer, a lower chamfer and a middle side surface parallel to each other, the lower chamfers between the two adjacent prefabricated laminated slabs form a lower chamfer bevel joint, the middle side surfaces between the two adjacent prefabricated laminated slabs form a flat joint, and the upper chamfers form an upper opening;

[0012] The cast-in-place layer is poured above the prefabricated laminated slab and between the upper openings of the two adjacent prefabricated laminated slabs;

[0013] The prefabricated laminated slab and the cast-in-place layer both have distribution steel bars perpendicular to the slab side direction and stress steel bars perpendicular to the slab end direction, and the distribution steel bars perpendicular to the slab side direction are not out of the steel bars, and the steel bars out of the steel bars are the stress steel bars perpendicular to the slab end direction in the prefabricated laminated slab.

[0014] To optimize the above technical scheme, the specific measures taken also include:

[0015] The width of the separated joint between the two adjacent prefabricated laminated slabs is 10mm, which is used to adjust the production and installation errors of the components.

[0016] As a preferred, the size of the upper opening is 20x60mm, so that the thickness of the cast-in-place layer at the joint position is 90-100mm, which is greater than 2 / 3 of the floor thickness, and the thickness of the joint steel bar protection layer and the remaining stiffness of the cast-in-place layer are improved; the size of the lower chamfer bevel joint is 10x10mm.

[0017] The first distribution steel bars are uniformly distributed in the prefabricated laminated slab perpendicular to the slab side direction, and the first stress steel bars are uniformly distributed in the prefabricated laminated slab perpendicular to the slab end direction; the second distribution steel bars are uniformly distributed in the cast-in-place layer perpendicular to the slab side direction, and the second stress steel bars are uniformly distributed in the cast-in-place layer perpendicular to the slab end direction.

[0018] Further, a plurality of truss steels are embedded in the prefabricated composite slab, and the top of the truss steel is located in the cast-in-place layer; the bottom of the truss steel is vertically bound with the first distribution steel and the first stress steel at the intersection of the two; and the top of the truss steel is vertically bound with the second distribution steel and the second stress steel at the intersection of the two.

[0019] Further, the truss steels are arranged in pairs, and each pair of truss steels is symmetrically arranged in opposite directions; the bottom of each pair of truss steels is bound with two adjacent first stress steels, and the top of each pair of truss steels is bound with the same second stress steel on the left and right sides, thereby forming a triangular support.

[0020] Preferably, the distance between the top of the truss steel group closest to the side of the prefabricated composite slab and the side of the prefabricated composite slab is L1, and L1 is not greater than 200 mm; and the minimum distance between the stress steel and the side of the prefabricated composite slab is greater than or equal to the minimum thickness of the steel protection layer.

[0021] Further, a joint construction steel is arranged across the adjacent two prefabricated composite slabs and the separation joint; the joint construction steel is connected with the truss steel perpendicularly; and the joint construction steel is arranged across the separation joint of the adjacent two prefabricated composite slabs in the direction of the side, and has equal lengths on the left and right sides of the separation joint.

[0022] Preferably, the reinforcement of the joint construction steel is 1.1 times the reinforcement of the prefabricated composite slab; and the distance between the end of the joint construction steel and the top of the truss steel group is L2, and L2 is not less than 15 times the diameter of the joint construction steel.

[0023] Preferably, the two side planes of the flat joint and the two side inclined planes of the upper opening of the flat joint are both fully paved with steel wire mesh.

[0024] Further, the flat joint is filled with polymer anti-cracking mortar; and the lower chamfered inclined joint is filled with modified silicone sealant.

[0025] The second aspect of the present application provides a construction method of a truss steel two-way composite slab separation joint structure, which comprises the following steps:

[0026] S1: hoisting the prefabricated composite slab, and controlling the distance between the two adjacent prefabricated composite slabs; the prefabricated composite slab is pre-embedded with a first distribution steel, a first stress steel and a truss steel, wherein the bottom of the truss steel is bound with the first distribution steel and the first stress steel.

[0027] S2: along the top of the flat joint, the two sides of the upper opening of the inclined joint full of dense steel mesh; then the joint structure reinforcement is arranged on the adjacent two prefabricated composite boards and the split joint;

[0028] S3: binding the second distribution steel and the second force steel of the cast-in-place layer;

[0029] S4: binding the top of the truss steel and the second distribution steel and the second force steel;

[0030] S5: pouring concrete between the prefabricated composite board and the upper opening;

[0031] S6: filling the split joint with crack-resistant material twice, filling the flat joint the first time and filling the lower chamfered inclined joint the second time.

[0032] Compared with the prior art, the beneficial effects of the present application are:

[0033] The present application provides a truss steel bidirectional composite board split joint structure and construction method. The structure includes a cast-in-place layer and a plurality of prefabricated composite boards, the plurality of prefabricated composite boards are arranged adjacent to each other, a split joint is formed between the adjacent two prefabricated composite boards, and the cast-in-place layer is poured above the composite boards; the composite board side is not reinforced, and only the board end is reinforced. The structure reduces the production and hoisting difficulty of the component, speeds up the construction speed, significantly improves the production efficiency and engineering quality, and ensures the construction safety.

[0034] The joint width between the composite boards of the structure is 10mm, which is used to adjust the error generated in the production and installation process of the component, and compared with the traditional integral joint or the split small joint which needs to be supported, the method is more convenient and easy to operate, saves resources and energy, and the joint quality is more guaranteed; compared with the close joint mode of the traditional split joint, the hoisting efficiency is higher, and the joint is less prone to cracking.

[0035] The joint part of the structure adopts polymer crack-resistant mortar and modified silicone sealant, which is filled twice after the completion of the main structure and secondary structure construction, effectively preventing common quality problems such as joint cracking and cast-in-place concrete dislocation at the joint, and the post-filling operation does not occupy the construction period of the main structure and the decoration stage.

[0036] The construction method greatly reduces the production difficulty of the component and the on-site hoisting requirement, improves the construction efficiency and installation fault tolerance, ensures the engineering quality, and realizes good comprehensive benefits. DETAILED DESCRIPTION

[0037] Figure 1 The structure diagram of the truss steel bidirectional composite board split joint structure of the present application.

[0038] Figure 2: A partial enlarged view of section A of the truss reinforcement bidirectional composite slab split joint structure of the present invention.

[0039] In the diagram: 1-Precast composite slab, 11-Truss reinforcement, 12-First main reinforcement, 13-First distribution reinforcement, 14-Upper chamfer, 15-Lower chamfer, 2-Cast-in-place layer, 21-Second main reinforcement, 22-Second distribution reinforcement, 23-Joint structural reinforcement, 24-Dense wire mesh, 3-Separated joint, 31-Flat joint, 32-Lower chamfered oblique joint. Detailed Implementation

[0040] The present invention will be further described in detail below through specific embodiments, but it should not be construed as limiting the scope of the subject matter of the present invention to the following embodiments. All technologies implemented based on the above content of the present invention fall within the scope of the present invention.

[0041] In the description of this invention, it should also be noted that:

[0042] The orientations or positional relationships described herein are based on the relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description. They are not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention. In this embodiment, for the sake of description, [the following is used]. Figure 1 The left and right directions are the side directions of the board, pointing perpendicularly. Figure 1 The orientation of inside and outside refers to the direction of the plate end.

[0043] In one embodiment, the present invention provides a truss reinforcement bidirectional composite slab split joint structure, such as... Figure 1 As shown, it includes several precast composite slabs 1 and a cast-in-place layer 2; the precast composite slabs 1 are arranged adjacently, with a separation joint 3 between two adjacent precast composite slabs 1; the adjacent sides of the precast composite slabs 1 respectively have an upper chamfer 14, a lower chamfer 15, and mutually parallel middle side surfaces, a lower chamfer oblique joint 32 is formed between the lower chamfers of two adjacent precast composite slabs 1, a flat joint 31 is formed between the middle side surfaces, and an upper opening is formed between the upper chamfers 14, as shown. Figure 2 As shown.

[0044] Preferably, the width of the separation joint between two adjacent prefabricated composite slabs 1 is 10mm, which is used to adjust for errors in component production and installation.

[0045] Preferably, the upper opening is 20×60mm in size, so that the thickness of the cast-in-place layer at the joint is 90-100mm, which is greater than 2 / 3 of the floor slab thickness, thereby increasing the thickness of the joint reinforcement protective layer and the remaining stiffness of the cast-in-place layer; the lower chamfer 15 is 10×10mm in size, which solves the problem of slight deviations in the joint elevation.

[0046] The cast-in-place layer 2 is poured above the precast composite slab 1 and between the upper openings of two adjacent precast composite slabs 1. Both the precast composite slab 1 and the cast-in-place layer 2 have distributed steel bars perpendicular to the side direction of the slab and stressed steel bars perpendicular to the end direction of the slab. The distributed steel bars perpendicular to the side direction of the slab are not exposed, and the exposed steel bars are the stressed steel bars in the precast composite slab 1 perpendicular to the end direction of the slab. This reduces the difficulty of production and installation of the composite slab and reduces the need for formwork support at the joints.

[0047] Preferably, the precast composite slab 1 has a first distribution steel bar 13 evenly distributed in the direction perpendicular to the side of the slab and a first load-bearing steel bar 12 evenly distributed in the direction perpendicular to the end of the slab; the cast-in-place layer 2 has a second distribution steel bar 22 evenly distributed in the direction perpendicular to the side of the slab and a second load-bearing steel bar 21 evenly distributed in the direction perpendicular to the end of the slab.

[0048] In one embodiment, it also includes a plurality of truss reinforcing bars 11, the bottom of which is embedded in the precast composite slab 1, and the top of which is located in the cast-in-place layer 2; the bottom of which is vertically tied to the first stressed reinforcing bar 12 and the first distributed reinforcing bar 13 at the intersection, and the top of which is vertically tied to the second stressed reinforcing bar 22 and the second distributed reinforcing bar 21 at the intersection.

[0049] The truss reinforcement bars 11 are arranged in pairs, and each pair of truss reinforcement bars 11 is arranged symmetrically and inclined towards each other. The bottom of the two truss reinforcement bars 11 in a pair are tied to the two adjacent first reinforcing bars 12 respectively, and the top is tied to the left and right sides of the same second reinforcing bar 21 to form a triangular support.

[0050] Preferably, the distance between the top of the truss reinforcement group closest to the side of the precast composite slab 1 and the side of the precast composite slab 1 is L1, where L1 is not greater than 200mm, and the minimum distance between the stressed reinforcement 12 and the side of the precast composite slab 1 is greater than or equal to the minimum thickness of the reinforcement protective layer.

[0051] It also includes joint construction reinforcement 23, which spans across two adjacent precast composite slabs 1 and the separation joint 3; the joint construction reinforcement 23 is perpendicularly connected to the truss reinforcement 11, and the joint construction reinforcement 23 spans across the separation joint 3 of two adjacent precast composite slabs 1 along the side direction of the slab, and has equal length on the left and right sides of the separation joint 3.

[0052] Preferably, the reinforcement of the joint structural steel bar 23 is 1.1 times greater than that of the precast composite slab 1; the distance between the end of the joint structural steel bar 23 and the top of the truss steel bar group is L2, and L2 is not less than 15 times the diameter of the joint structural steel bar 23, thereby improving the local stiffness of the joint and achieving the purpose of bidirectional force transmission.

[0053] Preferably, the top of the flat joint 31 and the two sides of the upper opening are fully covered with dense wire mesh 24; the flat joint 31 is filled with polymer crack-resistant mortar; the lower chamfered joint 32 is filled with modified silicone sealant, which effectively prevents common quality defects such as cracking of the board joint and misalignment of the cast-in-place concrete at the joint, and the later filling work does not occupy the construction period of the main structure and decoration stage.

[0054] In another embodiment, the present invention also provides a construction method for a truss-reinforced two-way composite slab with a separated joint, comprising the following steps:

[0055] S1: Hoist the precast composite slab 1 and control the distance between two adjacent precast composite slabs 2;

[0056] S2: Cover the top of the flat joint 31 and the two sides of the sloping joint of the upper opening with dense wire mesh 24; then set the joint construction steel bar 23 across the two adjacent precast composite slabs 1 and the separated joint 3.

[0057] S3: Bind the second distribution reinforcement 22 and the second load-bearing reinforcement 21 of the cast-in-place layer 2;

[0058] S4: Tie the top of the truss reinforcement 11 and the second distribution reinforcement 22 and the second load-bearing reinforcement 21;

[0059] S5: Pour concrete between the precast composite slab 1 and the upper opening;

[0060] S6: The crack-resistant material is used to fill the separated joint 3 in two stages. The first stage fills the flat joint 31, and the second stage fills the chamfered joint 32.

[0061] The following detailed description of the construction process of a specific embodiment further illustrates the present invention: Precast composite slabs 1, produced and cured to their designed strength, are hoisted into place. The width of the separation joint 3 between two adjacent precast composite slabs 1 is controlled to be 10mm. During production, the precast composite slabs 1 are pre-embedded with first distribution reinforcement 13, first load-bearing reinforcement 12, and truss reinforcement 11, wherein the bottom of the truss reinforcement 11 is tied to the first distribution reinforcement 13 and the first load-bearing reinforcement 12. After the precast composite slabs 1 are hoisted into place, dense wire mesh 24 is fully laid along the upper opening and separation joint 3 of the precast composite slabs 1. Joint reinforcement 23 is installed across the two adjacent precast composite slabs 1 and the separation joint 3; then the second distribution reinforcement 22 and the second main reinforcement 21 of the cast-in-place layer 2 are tied; then the top of the truss reinforcement 11 and the second distribution reinforcement 22 and the second main reinforcement 21 are tied; after the tying work is completed, concrete is poured between the precast composite slab 1 and the upper opening; after the main structure and secondary structure are completed, the separation joint 3 is filled with crack-resistant material in two stages. The first stage uses polymer crack-resistant mortar to fill the flat joint 31, and the second stage uses modified silicone sealant to fill the lower chamfered joint 32.

[0062] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent substitutions, and improvements made by those skilled in the art to the above embodiments without departing from the scope of the technical solution of the present invention, based on the technical essence of the present invention, shall still fall within the protection scope of the technical solution of the present invention.

Claims

1. A truss-reinforced bidirectional composite slab with a separate joint structure, characterized in that: It includes several precast composite slabs (1) and a cast-in-place layer (2); the several precast composite slabs (1) are arranged adjacent to each other, and a separation joint (3) is left between two adjacent precast composite slabs (1); The adjacent sides of the prefabricated composite slab (1) have an upper chamfer (14), a lower chamfer (15) and a middle side that are parallel to each other. A lower chamfer oblique joint (32) is formed between the lower chamfers (15) of two adjacent prefabricated composite slabs (1), a flat joint (31) is formed between the middle side, and an upper opening is formed between the upper chamfers (14). The cast-in-place layer (2) is poured above the precast composite slab (1) and between the upper openings of two adjacent precast composite slabs (1); Both the precast composite slab (1) and the cast-in-place layer (2) have distributed reinforcing bars perpendicular to the side direction of the slab and stressed reinforcing bars perpendicular to the end direction of the slab. The distributed reinforcing bars perpendicular to the side direction of the slab do not extend outwards, and the extended reinforcing bars are the stressed reinforcing bars in the precast composite slab (1) perpendicular to the end direction of the slab.

2. The truss reinforcement bidirectional composite slab split joint structure according to claim 1, characterized in that: The precast composite slab (1) has a first distribution steel bar (13) evenly distributed in the direction perpendicular to the side of the slab and a first load-bearing steel bar (12) evenly distributed in the direction perpendicular to the end of the slab; the cast-in-place layer (2) has a second distribution steel bar (22) evenly distributed in the direction perpendicular to the side of the slab and a second load-bearing steel bar (21) evenly distributed in the direction perpendicular to the end of the slab.

3. The truss reinforcement bidirectional composite slab split joint structure according to claim 2, characterized in that: It also includes several truss reinforcement bars (11), the bottom of which is embedded in the precast composite slab (1), and the top of which is located in the cast-in-place layer (2); the bottom of which is vertically tied to the first stressed reinforcement bar (12) and the first distributed reinforcement bar (13) at the intersection, and the top of which is vertically tied to the second stressed reinforcement bar (22) and the second distributed reinforcement bar (21) at the intersection.

4. The truss reinforcement bidirectional composite slab split joint structure according to claim 3, characterized in that: The truss reinforcement (11) is arranged in pairs, and each pair of truss reinforcement (11) is arranged symmetrically and inclined towards each other. The bottom of the two truss reinforcements (11) in a pair are tied to two adjacent first reinforcing bars (12) respectively, and the top is tied to the left and right sides of the same second reinforcing bar (21) to form a triangular support.

5. The truss reinforcement bidirectional composite slab split joint structure according to claim 4, characterized in that: The distance between the top of the truss reinforcement group closest to the side of the precast composite slab (1) and the side of the precast composite slab (1) is L1, where L1 is not greater than 200mm. The minimum distance between the stressed reinforcement (12) and the side of the precast composite slab (1) is greater than or equal to the minimum thickness of the reinforcement protective layer.

6. The truss reinforcement bidirectional composite slab split joint structure according to claim 4, characterized in that: It also includes joint construction reinforcement (23), which spans across two adjacent precast composite slabs (1) and the separation joint (3); the joint construction reinforcement (23) is perpendicularly connected to the truss reinforcement (11); the joint construction reinforcement (23) spans across the separation joint (3) of two adjacent precast composite slabs (1) along the side direction, and has equal length on the left and right sides of the separation joint (3).

7. The truss reinforcement bidirectional composite slab split joint structure according to claim 6, characterized in that: The distance between the end of the joint construction steel bar (23) and the top of the truss steel bar group is L2, and L2 is not less than 15 times the diameter of the joint construction steel bar (23).

8. The truss reinforcement bidirectional composite slab split joint structure according to claim 1, characterized in that: The top of the flat joint (31) and the two sides of the upper opening are fully covered with dense wire mesh (24); the flat joint (31) is filled with polymer crack-resistant mortar; the lower chamfered joint (32) is filled with modified silicone sealant.

9. A construction method for a truss-reinforced two-way composite slab with a separated joint, characterized in that, Includes the following steps: S1: Hoist the precast composite slab (1) and control the distance between two adjacent precast composite slabs (1); the precast composite slab (1) is pre-embedded with a first distribution steel bar (13), a first load-bearing steel bar (12) and a truss steel bar (11), wherein the bottom of the truss steel bar (11) is tied to the first distribution steel bar (13) and the first load-bearing steel bar (12); S2: The second distribution reinforcement (22) and the second load-bearing reinforcement (21) of the cast-in-place layer (2) are tied; S3: Tie the top of the truss reinforcement (11) and the second distribution reinforcement (22) and the second load-bearing reinforcement (21); S4: Pour concrete between the precast composite slab (1) and the upper opening.

10. The construction method of the truss reinforcement bidirectional composite slab with separated joint structure according to claim 9, characterized in that, Between steps S1 and S2, the following steps are also included: Dense wire mesh (24) is fully laid along both sides of the flat joint (31) and the two sides of the inclined joint of the upper opening; then joint structural reinforcement (23) is laid across the two adjacent precast composite slabs (1) and the separated joint (3); The steps following step S4 are as follows: The crack-resistant material is used to fill the split joint in two stages (3). The first stage fills the flat joint (31), and the second stage fills the chamfered joint (32).

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