A construction method and structure for a closely spaced ribbed floor slab

Abstract

This invention relates to the field of building construction technology and discloses a construction method and structure for a closely spaced ribbed floor slab. The method includes the following steps: marking the ribbed beam edge lines and core mold position lines on the bottom formwork; binding the ribbed beam skeleton along the ribbed beam edge lines; sequentially placing the precast bottom slab, core mold, and precast top slab; laying anti-buoyancy reinforcement on the precast top slab; and pouring concrete to form a complete floor slab integrating the closely spaced ribbed beams and the cast-in-place layer. This invention uses the precast bottom slab and precast top slab in conjunction with the core mold to form an assembled composite closely spaced ribbed floor slab, reducing the amount of cast-in-place concrete used on site, reducing the self-weight of the floor slab, and facilitating the realization of large spans; encapsulating the core mold inside the floor slab eliminates the problem of exposed ribbed beams protruding outwards, improving the utilization rate of the floor's net height; and using the skeleton reinforcement anchored into the ribbed beam skeleton to achieve horizontal positioning, with anti-buoyancy reinforcement set on the precast top slab to resist the buoyancy of the concrete, effectively solving the quality problems of core mold floating, horizontal displacement, and misalignment.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, and in particular to a method and structure for constructing a closely spaced ribbed floor slab. Background Technology

[0002] Ribbed slab floor systems are a type of floor structure composed of thin slabs and closely spaced ribs, widely used in large-span buildings. Traditional construction of ribbed slab floor systems primarily employs cast-in-place methods. The basic procedure involves: erecting a full-span support frame and bottom formwork; tying the rib beams and frame beam reinforcement to the bottom formwork; placing core molds between the rib beams; tying the slab surface reinforcement; pouring concrete monolithically; and removing the formwork after curing. This construction method creates a hollow structure by embedding lightweight infill within the floor slab, thereby reducing the floor's self-weight and improving sound and thermal insulation performance.

[0003] However, the aforementioned cast-in-place ribbed beam floor slab construction scheme, due to the use of cast-in-place concrete for both the floor slab and the ribs, results in a large structural self-weight, leading to increased beam and column cross-sectional dimensions and hindering the development of larger spans in buildings. In cast-in-place ribbed beam floor slabs, the bottom of the ribs (especially frame beams) protrudes beyond the bottom surface of the floor slab, forming exposed beams that occupy the effective clear height of the floor and reduce the utilization rate of interior space. Furthermore, during the cast-in-place concrete pouring process, the core mold is subjected to buoyancy and lateral impact forces generated by the concrete flow, making it prone to quality problems such as floating, horizontal displacement, and misalignment, affecting the structural performance and forming effect of the floor slab. Summary of the Invention

[0004] The purpose of this invention is to provide a construction method and structure for a closely spaced ribbed beam floor slab, in order to solve the problems in the prior art, simplify the construction process, reduce on-site material waste, and prevent the core mold from shifting during concrete pouring.

[0005] This invention provides a method for constructing a closely spaced ribbed beam floor slab, comprising the following steps: S1. According to the construction layout, complete the production of precast base slab, precast top slab and core mold. The precast base slab and the precast top slab are both pre-embedded with skeleton steel bars and the skeleton steel bars extend to all sides. S2. Lay the bottom template and mark the rib frame edge lines and core mold position lines on the bottom template; S3. Apply waterproof adhesive strips along the edge line of the rib frame; S4. Along the edge line of the rib skeleton, tie the rib skeleton. The rib skeleton is arranged in a crisscross pattern. Adjacent transverse rib skeletons and adjacent longitudinal rib skeletons together enclose multiple arrayed mold receiving cavities. S5. Place the precast bottom plate, the core mold and the precast top plate in sequence in the mold box cavity, and anchor the skeleton steel bars extending from the precast bottom plate and the precast top plate into the rib beam skeleton; S6. Lay anti-buoyancy reinforcement bars on the precast top slab and complete the pre-embedded installation of water and electricity pipelines; S7. Pour concrete to form a complete floor slab integrating the ribbed beams and the cast-in-place layer; S8. Remove the bottom template.

[0006] Preferably, in step S1, the thickness of the precast base plate is 25-35mm, and the thickness of the precast top plate is 45-55mm.

[0007] Preferably, in step S1, both the precast bottom slab and the precast top slab are precast in the factory. During precasting, the reinforcing steel bars inside the precast bottom slab are arranged at an upper position in the thickness direction of the slab, and the reinforcing steel bars inside the precast top slab are arranged in the center. Furthermore, the four side walls of both the precast bottom slab and the precast top slab are set as inclined surfaces.

[0008] Preferably, the inclined surface is 45°. Preferably, in step S1, the core mold is a polystyrene foam core mold, and the fire resistance rating of the polystyrene foam board is not lower than B1.

[0009] Preferably, in step S2, when the span of the bottom template is greater than 6m, it is arched at 2 / 1000 to 4 / 1000 of the shorter span direction, and the surface of the bottom template is also coated with a release agent.

[0010] Preferably, in step S3, the waterproof strip is a closed-cell sponge strip, and when it is pasted, the waterproof strip forms a closed loop along the inner edge of the rib beam.

[0011] Preferably, in step S4, when binding the rib beam skeleton, the short rib beam skeleton is bound first, and then the long rib beam skeleton is bound. The upper reinforcement of the short rib beam skeleton is located above the long rib beam skeleton, and the lower reinforcement of the short rib beam skeleton is located below the long rib beam skeleton.

[0012] Preferably, in step S6, the anti-buoyancy reinforcement is a double-layer bidirectional steel mesh, and the anti-buoyancy reinforcement is arranged longitudinally and transversely along the surface of the precast top slab and is tied and fixed to the rib beam skeleton.

[0013] Preferably, in step S6, when water and electricity pipelines need to pass through the polysilicon core mold, a pipe-passing hole is pre-drilled in the polysilicon core mold, and the area around the hole is sealed.

[0014] Preferably, in step S7, an immersion vibrator is used to vibrate the concrete during pouring. The insertion points of the vibrator are evenly arranged. During the vibration process, concrete is prevented from entering the bottom of the precast base plate, causing the core mold to float. After the concrete is poured, it is covered with a film and watered for curing.

[0015] The present invention also provides a ribbed beam floor structure, which is manufactured using the ribbed beam floor construction method described above. The ribbed beam floor structure includes: The rib frame is arranged in a crisscross pattern, with adjacent transverse rib frames and adjacent longitudinal rib frames together forming multiple arrayed mold housing cavities. A precast base plate is housed in the mold cavity, and a first skeleton steel bar is pre-embedded inside the precast base plate. The first skeleton steel bar extends outwards and is anchored into the rib skeleton. The core mold is set on the precast base plate and is limited by the rib frame around it; A precast top slab is placed on the core mold, and a second skeleton steel bar is precast inside the precast top slab. The second skeleton steel bar extends outwards and is anchored into the rib beam skeleton. Anti-buoyancy reinforcement bars are laid along the entire length of the upper side of the precast roof slab and are tied and fixed to the rib beam frame; The rib frame, precast base plate, core mold, precast top plate, and anti-buoyancy reinforcement are connected as a whole by cast-in-place concrete. The cast-in-place concrete fills the rib frame and covers the anti-buoyancy reinforcement and the upper surface of the precast top plate to form a cast-in-place layer.

[0016] Compared with existing technologies, this invention uses a precast base slab and a precast top slab in conjunction with a core mold to form an assembled, stacked, densely ribbed floor slab. This reduces the amount of on-site cast-in-place concrete, lightens the floor slab's self-weight, and facilitates large spans. Encapsulating the core mold inside the floor slab eliminates the problem of exposed beams protruding from the rib beams, improving the utilization rate of floor height. Horizontal restraint is achieved by anchoring the reinforcing steel bars into the rib beams, and anti-buoyancy reinforcement is set on the precast top slab to resist concrete buoyancy. Combined with anti-seepage strips along the rib beam edges to prevent grout leakage, this invention effectively solves the quality problems of core mold floating, horizontal displacement, and misalignment, ensuring the floor slab's forming effect and structural load-bearing performance. Attached Figure Description

[0017] Figure 1 This is a flowchart of the ribbed beam floor slab construction method provided in the embodiments of the present invention; Figure 2 This is a cross-sectional view of the ribbed beam floor system provided in an embodiment of the present invention; Figure 3 This is a partial view of the rib cage provided in an embodiment of the present invention; Figure 4 This is a top view of the ribbed beam floor structure provided in the embodiment of the present invention before concrete pouring; Figure 5 This is a schematic diagram of the structure of the precast base plate, core mold, precast top plate, and anti-buoyancy reinforcement provided in the embodiments of the present invention; Figure 6 This is a schematic diagram of the structure of the precast base plate and precast top plate provided in the embodiments of the present invention.

[0018] Explanation of reference numerals in the attached figures: 10. Rib frame; 100. Mold cavity; 11. Short rib frame; 12. Long rib frame; 20. Precast base slab; 21. First reinforcing steel reinforcement; 22. Inclined surface; 30. Core mold; 40. Precast roof slab; 41. Secondary reinforcing steel reinforcement; 50. Anti-buoyancy reinforcement; 60. Cast-in-place layer. Detailed Implementation

[0019] The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0020] See Figure 1 As shown, this embodiment provides a construction method for a closely spaced ribbed beam floor slab, including the following steps: Step S1, Construction Preparation: Before construction, familiarize yourself with the construction drawings, including the floor slab dimensions, ribbed beam arrangement, total floor slab thickness, and 60mm thick cast-in-place layer, among other design parameters. Based on the construction drawings, complete the layout of precast components, determining the specifications, quantity, and placement of precast components required for each area.

[0021] In this embodiment, the prefabricated components include a prefabricated base plate 20, a prefabricated top plate 40, and a core mold 30, all of which are prefabricated in the factory.

[0022] The precast base slab 20 and precast top slab 40 are both precast reinforced concrete thin slabs manufactured in the factory. After being transported to the construction site, they can be directly assembled and used without the need for on-site formwork and pouring. The precast base slab 20 and precast top slab 40 mainly serve structural and fixing functions. The overall load of the floor slab is borne by the closely ribbed beams. Therefore, the precast base slab 20 and precast top slab 40 should be as thin as possible while meeting their respective functions to minimize the self-weight of the floor slab. The remaining thickness is filled by the lightweight polycore mold 30, which ensures the designed thickness of the floor slab while achieving lightweighting.

[0023] See Figure 2 and 5As shown in Figure 6, in this embodiment, the thickness of the precast base slab 20 is 25mm to 35mm, preferably 30mm. A first reinforcing steel reinforcement 21 is pre-embedded inside the precast base slab 20. The first reinforcing steel reinforcement 21 is positioned slightly above the thickness of the precast base slab 20 to ensure that the thickness of the bottom concrete protective layer meets engineering requirements and to prevent cracking of the thin slab bottom surface. The first reinforcing steel reinforcement 21 extends outwards from all four sides of the precast base slab 20, serving as anchoring bars for subsequent anchoring into the rib beams. Each of the four sides of the precast base slab 20 is provided with an inclined surface 22. This inclined surface 22 extends obliquely from the slab surface towards the bottom, giving the precast base slab 20 a wedge-shaped cross-section that is larger at the top and smaller at the bottom. The inclination angle of the inclined surface 22 is 45°-60°, and in this embodiment, it is set to 45°.

[0024] The thickness of the precast top slab 40 is 45mm to 55mm, preferably 50mm. During prefabrication, a second reinforcing steel frame 41 is also pre-embedded inside the precast top slab 40. The second reinforcing steel frame 41 is arranged in the center of the thickness direction of the precast top slab 40, which can take into account the thickness of the protective layer on the upper and lower sides of the slab. The four sides of the precast top slab 40 are also provided with inclined surfaces 22, with an inclination angle of 45°. The inclined surfaces 22 can increase the contact area between the precast bottom slab 20 and the precast top slab 40 and the cast-in-place concrete, so that the precast part is more tightly bonded to the cast-in-place rib beam.

[0025] The core mold 30 uses a polystyrene (EPS) foam board core mold, and its thickness is determined in conjunction with the height of the ribbed beam, the thickness of the precast base plate 20, and the thickness of the precast top plate 40. The core mold 30 is custom-made in the factory according to the layout dimensions, that is, the dimensions of the mold box cavity 100. For irregular parts such as the edges of the floor slab and the edges of the columns, irregular core molds 30 are precisely customized according to the layout drawing to reduce material waste caused by on-site cutting.

[0026] Step S2, On-site hoisting and bottom formwork laying: Before hoisting, the layout diagram of the core mold 30, hoisting sequence, fixing method, and protection requirements must be clearly defined. Nylon slings should be used, and direct contact between steel wire ropes and the core mold 30 is strictly prohibited to avoid damage. The installation of the support frame and bottom formwork is carried out according to conventional methods and will not be elaborated here. The bottom formwork is fully laid on the support frame, the surface of the formwork is cleaned, and an environmentally friendly release agent is applied. When the span of the bottom formwork is greater than 6m, it should be cambered at 2 / 1000 to 4 / 1000 of the shorter span. After the formwork is erected, the elevation, flatness, and stability of the formwork are inspected. Only after passing the inspection can the next process be carried out.

[0027] On the laid base formwork, according to the design requirements of the construction drawings, mark the edge lines of the rib beam skeleton, the position lines of the core mold 30, and the pre-embedded and reserved positions of water and electricity installation pipes, etc. Mark the key positions with red paint to facilitate control and verification during construction and reduce installation errors.

[0028] Step S3: Applying the waterproofing strip: Before applying the waterproofing strips, clean the bottom formwork surface to ensure it is dry, free of oil, and free of standing water. Apply the waterproofing strips along the inner edge of the rib beam frame. Use 25mm x 5mm closed-cell sponge waterproofing strips, keeping them 30mm away from the edge of the core mold. Start applying the strips from one end of the roll, peeling off the release paper as you go, gently pressing the strip with both hands to ensure it is straight, continuous, and free from twisting or wrinkling. The waterproofing strips must form a closed loop; interruptions or omissions are strictly prohibited. Reinforcement strips must be applied at beam ends, column edges, and wall joints, and these areas must not be interrupted.

[0029] The purpose of the anti-seepage strip is to seal the gap between the edge of the precast base slab 20 and the bottom formwork, so as to prevent cement slurry from seeping from the edge of the precast base slab 20 to the bottom formwork when the rib beam concrete is poured, which would affect the flatness of the bottom surface of the floor slab after demolding.

[0030] Step S4, Rib cage 10 binding: See Figure 3 As shown, the rib cage 10 is tied according to the positioning lines. During tying, the short-direction rib cage 11 is tied first, followed by the long-direction rib cage 12. At the intersection of the two-way closely spaced ribs, the vertical position of the reinforcing bars needs to be clearly defined: the upper reinforcing bars of the short-direction rib cage 11 are located above the long-direction rib cage 12, and the lower reinforcing bars of the short-direction rib cage 11 are located below the long-direction rib cage 12. This ensures that the entire set of reinforcing bars of the short-direction rib cage 11 encloses the reinforcing bars of the long-direction rib cage 12 from both the top and bottom, forming a structure where the short-direction rib cage 11 encloses the long-direction rib cage 12. This structure avoids interference and collision between the reinforcing bars of the two ribs at the intersection points, ensuring that the reinforcing bar cages of both ribs remain continuous and intact. After the concrete is poured, both the long and short-direction reinforcing bars can fully exert their load-bearing capacity. The longitudinal and transverse reinforcing bars of the rib beam skeleton 10 are fixed together by stirrups, which are arranged at intervals along the length of the rib beam skeleton 10 to ensure that the skeleton does not fall apart during concrete pouring. The bending radius of the stirrups shall comply with the requirements of current specifications and shall not be bent into sharp bends. If the rib beam is not continuous, its bottom reinforcing bars shall meet the anchorage length requirements at the supports. When cutting the main reinforcing bars and stirrups of the rib beam, attention should be paid to the thickness of the concrete cover. In a dry indoor environment, the minimum concrete cover thickness of the rib beam skeleton 40 is 20mm.

[0031] After the reinforcing bars are tied, a concealed works inspection is conducted, and only after the inspection is passed can the next process begin.

[0032] It should be noted that the order of binding the rib cage 10 and installing the precast base plate 20 can be selected according to the actual construction progress. That is, the rib cage 10 can be bound first and then the precast base plate 20 can be placed, or the precast base plate 20 can be placed first and then the rib cage 10 can be bound. Both orders can achieve the technical solution of the present invention.

[0033] Step S5: Installation of prefabricated composite hollow structure: See Figure 2-4 As shown, after the rib frame 10 is tied and accepted, the precast bottom plate 20, the core mold 30 and the precast top plate 40 are placed in sequence in the multiple arrays of mold box cavities 100 formed by the rib frame 10 according to their positioning.

[0034] When placing the precast base slab 20, align it stably with the installation area of ​​the core mold 30. The first reinforcing bars 21 extending from the perimeter of the precast base slab 20 extend into the surrounding rib beam skeleton 10. The precast base slab 20 is placed on the bottom formwork. Since anti-seepage strips have been pre-attached to the bottom formwork, the edges of the precast base slab 20 are tightly fitted with the anti-seepage strips, which can effectively prevent cement slurry from seeping from the edges of the base slab during subsequent concrete pouring.

[0035] The core mold 30 is placed on top of the precast base plate 20, and the core mold 30 is limited by the rib frame 10 around its perimeter. The precast top plate 40 is placed on top of the core mold 30, and the second skeleton steel bars 41 extending from the perimeter of the precast top plate 40 also extend into the surrounding rib frame 10.

[0036] Step S6: Binding of 60mm rebar in cast-in-place layer and pre-installation of water and electricity pipelines: After the precast base slab 20, core mold 30, and precast top slab 40 are installed, a continuous anti-buoyancy reinforcement bar 50 is laid above the precast top slab 40. The anti-buoyancy reinforcement bar 50 is arranged longitudinally and transversely along the surface of the precast top slab 40 and is tied and fixed to the rib beam frame 10. The spacing and position of the anti-buoyancy reinforcement bar 50 are in accordance with the design requirements. The function of the anti-buoyancy reinforcement bar 50 is to hold the precast top slab 40, core mold 30, and precast base slab 20 together during concrete pouring, preventing the core mold 30 from floating or shifting due to the buoyancy and lateral impact of the concrete. It also serves as the load-bearing reinforcement of the concrete floor slab structure.

[0037] In this embodiment, the anti-buoyancy reinforcement 50 adopts a double-layer bidirectional steel mesh, forming a top cast-in-place layer 60 on top of the precast slab 40 after concrete pouring. It should be noted that after concrete pouring, densely ribbed beams are formed at the rib beam skeleton 10. The thickness of the precast slab 40 and the top cast-in-place layer 60 is determined according to design requirements, typically 90mm to 150mm. The diameter and spacing of the double-layer bidirectional steel mesh are determined according to design requirements. For example, if the slab thickness is 90mm, the cast-in-place layer 60 area uses a C8@200 double-layer bidirectional steel mesh; for 120mm and 150mm thick cast-in-place layers 60 areas, a C10@200 double-layer bidirectional steel mesh is used.

[0038] Water and electricity pipelines should be preferentially laid in the rib beam area because the rib beam area is cast-in-place concrete, providing sufficient space to accommodate the pipelines. When water and electricity pipelines must pass through the core mold 30, penetration holes should be pre-drilled in the core mold 30, and the holes should be tightly sealed with expanding foam or cement grout to prevent cement grout from entering the core mold 30 during concrete pouring. Simultaneously, steel or PVC sleeves should be pre-embedded in the rib beams where water and electricity pipelines pass through.

[0039] Step S7: Pour concrete to form a complete floor slab integrating the ribbed beams and the cast-in-place layer. After all the above procedures are completed, concrete pouring shall be carried out. Appropriate grade concrete shall be used for different parts during pouring, and the process shall be continuous.

[0040] An immersion vibrator is used for compaction, with rapid insertion and slow withdrawal, and the insertion points are evenly spaced and moved point by point. During vibration, care should be taken to prevent concrete from entering the bottom of the precast base slab 20. Because there is a joint between the precast base slab 20 and the bottom formwork, although anti-seepage strips have been applied, there is still a risk of a small amount of cement slurry seeping in. Concrete entering the bottom of the precast base slab 20 will generate buoyancy, potentially lifting the precast base slab 20 along with the core mold 30. Therefore, excessive vibration should be avoided at the edges of the precast base slab 20, and the concrete pouring speed should be controlled.

[0041] After the concrete is poured, immediately cover it with plastic film and water it to keep it moist for curing.

[0042] Step S8: Remove the bottom formwork. After the structural concrete reaches the design strength, the bottom formwork is removed. Removal follows the principle of supporting the formwork before dismantling, and proceeding from top to bottom, starting from the mid-span and moving outwards to avoid impacting the core mold 30.

[0043] After the formwork is removed, clean up any remaining waterproofing strips and grout from the bottom of the slab to ensure that the bottom edges and corners are straight and the surface is flat.

[0044] In this embodiment, the thicknesses of the precast base plate 20, precast top plate 40, core mold 30, and top cast-in-place layer 60 are determined in conjunction with the height of the closely ribbed beam.

[0045] After the height of the ribbed beams is determined by structural stress calculations, the thickness of the top cast-in-place layer 60 is determined based on floor load and pipeline layout requirements, typically ranging from 90mm to 150mm. The thickness of the precast base slab 20 is taken as the minimum value sufficient to satisfy the function of the bottom formwork, preferably 25mm to 35mm, and more preferably 30mm. The thickness of the precast top slab 40 is taken as the minimum value sufficient to reliably fix the core mold 30 to prevent it from floating during concrete pouring, preferably 45mm to 55mm, and more preferably 50mm. The thickness of the core mold 30 is the difference between the height of the ribbed beams and the thicknesses of the precast base slab 20, the precast top slab 40, and the top cast-in-place layer 60.

[0046] The precast base slab 20 and precast top slab 40 primarily serve structural and fixing functions. The overall load-bearing capacity of the floor slab is borne by the rib beams. Therefore, the precast base slab 20 and precast top slab 40 should be as thin as possible while fulfilling their respective functions to minimize the self-weight of the floor slab. The remaining thickness is filled by lightweight polycore mold 30, which ensures the designed thickness of the floor slab while achieving lightweighting.

[0047] Taking a project where the height of the closely spaced ribbed beams in a floor slab is 400mm as an example: The thickness of the top cast-in-place layer 60 is 90mm, the thickness of the precast bottom plate 20 is 30mm, and the thickness of the precast top plate 40 is 50mm. Therefore, the thickness of the core mold 30 is 400mm-90mm-30mm-50mm=230mm.

[0048] During construction, a 30mm thick precast base slab 20 and a 50mm thick precast top slab 40 are prefabricated in the factory, and a 230mm thick EPS core mold 30 is custom-made. On-site, the formwork is laid, lines are laid out, waterproof strips are applied, and the rib beam skeleton 10 is tied in sequence. Then, the precast base slab 20, core mold 30, and precast top slab 40 are placed, anti-buoyancy reinforcement 50 is laid, concrete is poured, and after curing, the formwork is removed, thus completing the construction of the closely ribbed beam floor slab.

[0049] See Figure 2-6 As shown, this embodiment also provides a ribbed beam floor structure, which is constructed using the ribbed beam floor construction method described above. The ribbed beam floor structure includes: The rib frame 10 is arranged in a crisscross pattern, and the adjacent transverse rib frames and the adjacent longitudinal rib frames together enclose and form multiple arrayed mold receiving cavities 100. The precast base plate 20 is housed in the mold box cavity 100. The first skeleton steel bar 21 is pre-embedded inside the precast base plate 20. The first skeleton steel bar 21 extends outward and is anchored into the rib beam skeleton 10. The core mold 30 is set on the precast base plate 20 and is limited by the rib frame 10 around it; The precast top slab 40 is placed on the core mold 30. The precast top slab 40 has a second skeleton steel bar 41 embedded inside. The second skeleton steel bar 41 extends outwards and is anchored into the rib beam skeleton 10. Anti-buoyancy reinforcement 50 is laid along its length on the upper side of the precast top slab 40 and tied and fixed to the rib frame 10; The ribbed frame 10, precast base slab 20, core mold 30, precast top slab 40, and anti-buoyancy reinforcement 50 are connected as a whole by cast-in-place concrete. The cast-in-place concrete fills the ribbed frame 10 to form a densely ribbed beam and covers the upper surface of the anti-buoyancy reinforcement 50 and the precast top slab 40, forming the top cast-in-place layer 60. It should be understood that the concrete also fills the gaps in all structures and forms a complete floor structure after solidification.

[0050] The above description, based on the embodiments shown in the figures, details the structure, features, and effects of the present invention. The above description is only a preferred embodiment of the present invention, but the present invention is not limited to the scope of implementation shown in the figures. Any changes made in accordance with the concept of the present invention, or equivalent embodiments modified to have equivalent changes, that do not exceed the spirit covered by the specification and figures, should be within the protection scope of the present invention.

Claims

1. A construction method for a closely ribbed beam floor slab, characterized in that, Includes the following steps: S1. According to the construction layout, complete the production of precast base slab, precast top slab and core mold. The precast base slab and the precast top slab are both pre-embedded with skeleton steel bars and the skeleton steel bars extend to all sides. S2. Lay the bottom template and mark the rib frame edge lines and core mold position lines on the bottom template; S3. Apply waterproof adhesive strips along the edge line of the rib frame; S4. Along the edge line of the rib skeleton, tie the rib skeleton. The rib skeleton is arranged in a crisscross pattern. Adjacent transverse rib skeletons and adjacent longitudinal rib skeletons together enclose multiple arrayed mold receiving cavities. S5. Place the precast bottom plate, the core mold and the precast top plate in sequence in the mold box cavity, and anchor the skeleton steel bars extending from the precast bottom plate and the precast top plate into the rib beam skeleton; S6. Lay anti-buoyancy reinforcement bars on the precast top slab and complete the pre-embedded installation of water and electricity pipelines; S7. Pour concrete to form a complete floor slab integrating the ribbed beams and the cast-in-place layer; S8. Remove the bottom template.

2. The construction method for a closely spaced ribbed beam floor slab according to claim 1, characterized in that, In step S1, the thickness of the precast base plate is 25-35mm, and the thickness of the precast top plate is 45-55mm.

3. The construction method for a closely spaced ribbed beam floor slab according to claim 1, characterized in that, In step S1, both the precast bottom slab and the precast top slab are precast in the factory. During precasting, the reinforcing steel bars inside the precast bottom slab are arranged at an upper position in the thickness direction of the slab, and the reinforcing steel bars inside the precast top slab are arranged in the center. The four side walls of both the precast bottom slab and the precast top slab are set as inclined surfaces.

4. The construction method for a closely spaced ribbed beam floor slab according to claim 1, characterized in that, In step S2, when the span of the bottom template is greater than 6m, it is arched at 2 / 1000 to 4 / 1000 of the shorter span direction, and a release agent is applied to the surface of the bottom template.

5. The construction method for a closely spaced ribbed beam floor slab according to claim 1, characterized in that, In step S3, the waterproof strip is a closed-cell sponge strip, and when it is pasted, the waterproof strip forms a closed loop along the inner edge of the rib beam.

6. The construction method for a closely spaced ribbed beam floor slab according to claim 1, characterized in that, In step S4, when tying the rib beam skeleton, the short rib beam skeleton is tied first, and then the long rib beam skeleton is tied. The upper reinforcement of the short rib beam skeleton is located above the long rib beam skeleton, and the lower reinforcement of the short rib beam skeleton is located below the long rib beam skeleton.

7. The construction method for a closely spaced ribbed beam floor slab according to claim 1, characterized in that, In step S6, the anti-buoyancy reinforcement is a double-layer bidirectional steel mesh. The anti-buoyancy reinforcement is arranged longitudinally and transversely along the surface of the precast top slab and is tied and fixed to the rib beam skeleton.

8. The construction method for a closely spaced ribbed beam floor slab according to claim 1, characterized in that, In step S6, water and electricity pipelines are arranged in the rib beam area. When water and electricity pipelines need to pass through the core mold, through holes are pre-drilled in the core mold and the holes are sealed around them.

9. The construction method for a closely spaced ribbed beam floor slab according to claim 1, characterized in that, In step S7, an immersion vibrator is used to vibrate the concrete during pouring. The insertion points of the vibrator are evenly arranged. During the vibration process, concrete is prevented from entering the bottom of the precast base plate, which would cause the core mold to float. After the concrete is poured, it is covered with a film and watered for curing.

10. A closely ribbed beam floor structure, characterized in that, The ribbed beam floor slab is constructed using the method described in claims 1-9, wherein the ribbed beam floor slab structure includes: The rib frame is arranged in a crisscross pattern, with adjacent transverse rib frames and adjacent longitudinal rib frames together forming multiple arrayed mold housing cavities. A precast base plate is housed in the mold cavity, and a first skeleton steel bar is pre-embedded inside the precast base plate. The first skeleton steel bar extends outwards and is anchored into the rib skeleton. The core mold is set on the precast base plate and is limited by the rib frame around it; A precast top slab is placed on the core mold, and a second skeleton steel bar is precast inside the precast top slab. The second skeleton steel bar extends outwards and is anchored into the rib beam skeleton. Anti-buoyancy reinforcement bars are laid along the entire length of the upper side of the precast roof slab and are tied and fixed to the rib beam frame; The rib frame, precast base plate, core mold, precast top plate, and anti-buoyancy reinforcement are connected as a whole by cast-in-place concrete. The cast-in-place concrete fills the rib frame and covers the anti-buoyancy reinforcement and the upper surface of the precast top plate to form a cast-in-place layer.

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