Composite prefabricated floor slab and construction method thereof

Abstract

The present disclosure provides a composite prefabricated floor slab, comprising a base plate, a layer plate stacked on the top surface of the base plate, and a bottom plate steel bar arranged on the base plate. The base plate and the layer plate are both prefabricated with concrete; the area where the layer plate contacts the base plate is smaller than the area of ​​the base plate, and the top surface of the layer plate is the finished surface of the floor slab structure; the bottom plate steel bar is covered inside the base plate. The area where the base plate does not contact the layer plate forms a cast-in-place concrete area. The finished surface of the floor slab structure of the composite prefabricated floor slab disclosed in the present disclosure is a structural floor slab surface that meets the use requirements of reinforced concrete floor slabs. At the construction site, it is not necessary to cast concrete on the top surface of the layer plate to meet the structural floor slab thickness required by the design, thereby reducing wet work on site and improving construction efficiency.

Description

Technical Field

[0001] The present invention relates to the field of prefabricated buildings, and in particular to a composite prefabricated floor slab and a construction method thereof. Background Art

[0002] Prefabricated buildings refer to buildings that are assembled on site using prefabricated components. The advantages of this type of building are fast construction speed, less restrictions on climatic conditions, labor saving and improved building quality. At present, reinforced concrete composite slabs are generally used in assembled monolithic concrete structures. The practice is to set truss steel bars on the upper surface of the concrete prefabricated slab (not the finished surface of the slab structure), and cast a concrete composite layer on site to cover the truss steel bars to make it an integral concrete structure that bears the load together. The installation of truss steel bars increases the steel content and costs.

[0003] The cast-in-place overlay layer on the precast concrete slab requires a large amount of concrete to be poured on site, involving a lot of wet work, and the solidification of the overlay layer concrete takes a certain amount of time. The supporting devices of components such as precast walls need to be fixed on the slab, and this process must be carried out after the overlay layer concrete solidifies, resulting in low construction efficiency.

[0004] Usually, steel bars (ribs) need to extend from the sides of precast concrete panels to achieve connection with adjacent panels or panel supports. However, the existence of ribs greatly reduces the efficiency of industrialized production of precast concrete panels, and the spacing required for ribs in different projects and panels is not the same, resulting in low reuse rate of side formwork for making precast concrete panels. Summary of the invention

[0005] In order to solve at least one of the above technical problems, the present disclosure provides the following contents.

[0006] According to one aspect of the present disclosure, a composite prefabricated floor slab comprises:

[0007] A base plate, formed by precast concrete;

[0008] A layer plate is prefabricated with concrete and formed on the top surface of the base plate, the contact area between the layer plate and the base plate is smaller than the area of ​​the base plate, and the top surface of the layer plate is the finished surface of the floor structure; and

[0009] A slab bottom steel bar, the slab bottom steel bar is arranged on the base plate and covered inside the base plate;

[0010] The area where the base plate is not in contact with the layer plate forms a cast-in-place concrete area.

[0011] According to at least one embodiment of the present disclosure, at least a portion of the edge of the base plate is provided with a groove for placing the connecting steel bars, and the groove extends from the edge to the inner side of the edge.

[0012] According to at least one embodiment of the present disclosure, the floor plate is provided with a slab top reinforcement, and the slab top reinforcement is covered inside the floor plate.

[0013] According to at least one embodiment of the present disclosure, at least a portion of the edge of the layer plate is provided with the groove for placing the connecting steel bars, and the groove extends from the edge to the inner side of the edge.

[0014] According to at least one embodiment of the present disclosure, the slab bottom reinforcement and / or the slab top reinforcement are steel meshes.

[0015] According to at least one embodiment of the present disclosure, the thickness of the substrate at the bottom of the groove ranges from 20 mm to 60 mm; and the total thickness of the substrate and the layer plate is not less than 80 mm.

[0016] According to at least one embodiment of the present disclosure, the cross-sectional shape of the groove is rectangular, trapezoidal, V-shaped, semicircular or doorway-shaped.

[0017] According to at least one embodiment of the present disclosure, the inner wall of the groove is configured as an uneven surface.

[0018] According to at least one embodiment of the present disclosure, an inner wall of the groove is provided with corrugated grooves to form the uneven surface.

[0019] According to at least one embodiment of the present disclosure, in the direction in which the groove extends from the edge where the groove is located to the inner side of the edge where the groove is located, the width of the groove is the same or the width of the groove increases to form a shape that is narrow outside and wide inside.

[0020] According to at least one embodiment of the present disclosure, in a direction in which the groove extends from the edge where the groove is located toward the inner side of the edge where the groove is located, the depth of the groove is the same or the depth of the groove decreases.

[0021] According to at least one embodiment of the present disclosure, the bottom surface of the groove includes an inclined surface and / or a stepped surface.

[0022] According to at least one embodiment of the present disclosure, pipelines are pre-buried inside the substrate, and the substrate is rectangular;

[0023] The four corners of the base plate are provided with enlarged grooves, and the pipelines extend into the enlarged grooves for connection; or the pipelines extend from the sides of the base plate for connection.

[0024] According to at least one embodiment of the present disclosure, pipelines are pre-buried inside the layer plate, and the layer plate is rectangular;

[0025] The pipeline extends into the cast-in-place concrete area for connection; or the four corners of the layer plate are provided with enlarged grooves, and the pipeline extends into the enlarged grooves for connection; or the pipeline extends to the outside of the side of the base plate for connection.

[0026] According to another aspect of the present disclosure, a construction method of the composite prefabricated floor slab as described above comprises:

[0027] Setting the composite prefabricated floor slab in place;

[0028] A groove is provided at an edge of the base plate for connection, and a connecting steel bar is placed in the groove; and

[0029] Concrete is poured at least in the concrete cast-in-place area and the groove.

[0030] According to at least one embodiment of the present disclosure, at least two connecting steel bars are placed in the groove so that at least two connecting steel bars are arranged at intervals in the same horizontal plane; or at least two support negative moment steel bars are placed in the groove so that at least two support negative moment steel bars are arranged at intervals in the same horizontal plane. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings illustrate exemplary embodiments of the present disclosure and together with the description serve to explain the principles of the present disclosure. These drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification.

[0032] Figure 1 1 is a schematic diagram of a three-dimensional structure of an exemplary composite prefabricated floor according to the present disclosure.

[0033] Figure 2 yes Figure 1 Schematic diagram of the connection method of the illustrated embodiment.

[0034] Figure 3 It is a schematic diagram of the three-dimensional structure of another embodiment of an exemplary composite prefabricated floor slab according to the present disclosure.

[0035] Figure 4 yes Figure 3 Schematic diagram of the connection method of the illustrated embodiment.

[0036] Figure 5 It is a schematic diagram of the three-dimensional structure of another embodiment of an exemplary composite prefabricated floor slab according to the present disclosure.

[0037] Figure 6 yes Figure 5 Schematic diagram of the connection method of the illustrated embodiment.

[0038] Figure 7 It is a schematic diagram of the three-dimensional structure of another embodiment of an exemplary composite prefabricated floor slab according to the present disclosure.

[0039] Figure 8 yes Figure 7 Schematic diagram of the connection method of the illustrated embodiment.

[0040] Fig. 9 It is a schematic diagram of the connection method of the panels in the exemplary composite prefabricated floor slab in which the base plate adopts the thin edge form according to the present disclosure.

[0041] Fig.10 It is a schematic diagram of the connection method of the slabs in the exemplary composite prefabricated floor slab in which the base plate adopts the grooved form according to the present disclosure.

[0042] Fig.11 Schematic diagram of an embodiment of a groove in an exemplary composite prefabricated floor according to the present disclosure.

[0043] Fig.12 1 is a top view of a connection structure with slab top reinforcement in an exemplary composite prefabricated floor slab of the present disclosure.

[0044] Fig.13 yes Fig.12 A cross-sectional view of the connection structure shown.

[0045] Fig.14 It is a schematic diagram of the composite prefabricated floor slab disclosed in the present invention using angle steel supports during construction.

[0046] Figures 15a to 15d It is a structural schematic diagram of different cross-sectional shapes of the grooves in the composite prefabricated floor slab disclosed in the present invention.

[0047] Figures 16a to 16c It is a schematic diagram of different implementation methods of varying the groove width in the composite prefabricated floor slab disclosed in the present invention.

[0048] Fig.17a and Fig.17b It is a schematic diagram of different variations of the bottom surface of the groove in the composite prefabricated floor slab disclosed in the present invention.

[0049] Fig.18a and Fig.18b It is a schematic diagram of the arrangement of connecting steel bars in grooves or negative moment steel bars in supports in the construction method of the composite prefabricated floor slab disclosed in the present invention. DETAILED DESCRIPTION

[0050] The present disclosure is further described in detail below in conjunction with the accompanying drawings and implementations. It is understood that the specific implementations described herein are only used to explain the relevant content, rather than to limit the present disclosure. It should also be noted that, for ease of description, only the parts related to the present disclosure are shown in the accompanying drawings.

[0051] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in the present disclosure may be combined with each other. The present disclosure will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0052] Existing reinforced concrete composite slabs require on-site pouring of concrete on the entire prefabricated part, and truss steel bars need to be configured at the overlapping surface of the cast-in-place part and the prefabricated part. The presence of truss steel bars significantly increases the steel content of the slab (the steel content per unit area), increases the cost of the building structure, and becomes an important obstacle to the development of prefabricated buildings. During construction, a large amount of concrete needs to be poured on-site, and there are many wet operations. In addition, it takes a certain amount of time for the concrete of the composite layer to solidify, and the supporting devices of prefabricated walls and other components need to be fixed on the slab. This process must be carried out after the concrete of the composite layer solidifies, resulting in low construction efficiency.

[0053] In addition, the reinforcement bars currently used in reinforced concrete composite slabs have greatly reduced the efficiency of the industrialized production of precast concrete slabs, and the spacing required for the reinforcement bars in different projects and different panels is not the same, resulting in a low reuse rate of the side formwork for making precast concrete slabs.

[0054] In order to solve at least one of the above existing technical problems, according to an embodiment of the present disclosure, a composite prefabricated floor 1 is provided, and the composite prefabricated floor 1 includes a base plate 11, a layer plate 12 and a bottom steel bar 3. The base plate 11 and the layer plate 12 are prefabricated by pouring concrete into a mold, and their shapes are not limited here, and can be designed into corresponding different shapes as needed, such as a common rectangle, square, and L-shaped or curved shape. When the base plate 11 and the layer plate 12 are prefabricated, the base plate 11 and the layer plate 12 are formed by setting a corresponding mold on the mold table, pouring concrete into the mold to form the base plate 11 and the layer plate 12, so that the layer plate 12 is directly formed on the top surface of the base plate 11. The shape of the layer plate 12 is not limited here either, and can be designed into different corresponding shapes as needed, such as the usual rectangle, square, L-shaped or curved shape, etc.; however, the area where the layer plate 12 contacts the substrate 11 is smaller than the area of ​​the substrate 11, that is, only part of the top surface of the substrate 11 is covered by the layer plate 12, and part of the top surface of the substrate 11 is not covered by the layer plate 12. The area where the top surface of the substrate 11 is not in contact with the layer plate 12 (the uncovered area) forms a cast-in-place concrete area, and concrete is poured into the cast-in-place concrete area during construction to fill it and form an integral load-bearing floor slab. When forming the substrate 11 and the layer plate 12, they are directly prefabricated according to the target thickness of the floor slab, so that the total thickness of the substrate 11 and the layer plate 12 reaches the target thickness of the floor slab. Among them, the thickness of the substrate 11 is too small and is easily damaged during transportation and construction, so the thickness of the substrate 11 is not less than 20 mm. The total thickness of the substrate 11 and the layer plate 12, that is, the target thickness of the floor slab, is not less than 80 mm to increase the rigidity of the prefabricated floor slab. The top surface of the layer 12 is the finished surface of the floor structure, which is a structural floor surface that meets the requirements for the use of reinforced concrete floors. At the construction site, there is no need to pour concrete on the top surface of the layer 12 to meet the structural floor thickness required by the design, reducing wet work on site, and after the composite prefabricated floor 1 is set in place, there is no need to wait for the setting time of the concrete, and the supporting devices of components such as prefabricated walls can be directly supported and fixed on the floor, thereby improving construction efficiency. By combining the base plate 11 and the layer 12, the composite prefabricated floor 1 has better integrity and can replace the role of truss steel bars in traditional composite plates, thereby reducing the amount of steel bars used in the truss and saving component costs.

[0055] The bottom reinforcement 3 is arranged inside the base plate 11. The bottom reinforcement 3 is the tension reinforcement laid under the plate. The bottom reinforcement 3 is arranged at the lower part of the base plate 11 (close to the bottom of the base plate 11). The lower surface of the reinforcement meets the protective layer requirement from the bottom surface of the base plate 11, and the bottom reinforcement 3 is covered inside the base plate 11, and does not extend from the side of the base plate 11, that is, there is no beard reinforcement, and there is no truss reinforcement in the base plate 11. When making the base plate 11 disclosed in the present invention, the corresponding bottom reinforcement 3 is arranged in the mold, and then concrete is poured into the mold to form an integral force-bearing structure, which avoids the problem of low reuse rate of the side molds for making concrete precast panels due to the different spacing required for the beard reinforcement of different projects and different plates, and improves the efficiency of the industrial production of the precast panel part of the composite floor. The role of the truss reinforcement in the existing precast floor is mainly to increase the rigidity of the precast panel during the transportation and hoisting of the precast panel. After pouring the concrete superposition layer, the truss steel bar has almost no contribution to the overall rigidity of the floor slab, and its main function for the superposition floor slab is to increase the shear bearing capacity of the superposition surface. The base plate 11 and the layer plate 12 of the prefabricated superposition floor slab 1 of the present disclosure are cast in one time, so the interior of the present disclosure does not need to be provided with truss steel bars, which reduces the amount of steel bars used.

[0056] According to different connection methods, the composite prefabricated floor slab 1 disclosed in the present invention can adopt a variety of different embodiments.

[0057] In an optional embodiment of the present disclosure, in order to realize the function of connecting the bottom reinforcement of the plate with the adjacent plate or plate support, a groove 13 for placing the connecting steel bar 5 is provided at least on part of the edge (edge ​​for connection) of the base plate 11. One end of the groove 13 is opened at the edge of the base plate 11, so that a notch is formed on the edge so that the connecting steel bar 5 can extend out of the edge from the notch. The groove 13 extends from the edge where it is located to the inner side of the edge where it is located, and can extend in a straight line direction. The direction of extension can be the main force direction. The cross section of the groove 13 is not limited to a rectangle, and other shapes such as a trapezoid, a V-shape, a semicircle or a doorway shape can also be adopted; the doorway shape refers to a combination of a semicircle and a rectangle, that is, the lower part of the groove is a semicircle, and the upper part of the semicircle is adjacent to a rectangle. At the same time, the shape, width, depth and other parameters of the cross section of the groove 13 can also be changed along the extended length direction. During construction, without the beard bar, the concrete precast panel can be conveniently hoisted, assembled, etc. After being set in place, the connecting steel bar 5 can be placed in the corresponding groove 13, and then concrete can be poured on site in the groove 13 to combine the connecting steel bar 5 with the cast-in-place concrete to form a connection. If the thickness of the base plate 11 at the bottom of the groove 13 is too large, the steel bar cannot be effectively overlapped, so the thickness of the base plate 11 at the bottom of the groove 13 is not more than 60mm.

[0058] See also Fig.15aThe cross-section of the groove shown is a rectangular groove 131, and the bottom corners of the rectangular groove 131 can be rounded. The production mold with a rectangular cross-section is simple, and the rounded corners at the bottom corners are convenient for removing the mold.

[0059] See also Fig.15b The cross-sectional form of the groove shown, the cross-sectional form of the groove 131 can be trapezoidal, and the width of the upper part of the groove 131 is greater than the width of the bottom. The mold of this shape is slightly complicated, but it is easy to remove and easy to cast while achieving a larger width of the tooth bottom and the groove top.

[0060] See also Fig.15c The cross-section of the groove shown in the figure can be V-shaped, and the bottom of the V-shaped groove 131 can be slightly smoothed, for example, by making a rounded corner or a chamfered corner. The V-shaped cross-section makes the mold slightly complicated, but it is easy to remove and pour, and the bottom of the groove 131 also serves as a steel bar limiter.

[0061] See also Fig.15d The cross-section of the groove shown in the figure can be a door-shaped cross-section of the groove 131, which means that the lower part of the groove 131 adopts a semicircular cross-section, and the upper part of the semicircular cross-section is a rectangular cross-section, and the two cross-section shapes are combined to form a door-shaped cross-section. With this cross-section shape, the mold is more complicated, but it is easy to remove the mold.

[0062] Optional, see Fig.16a , Fig.16b and Fig.16c 1 and 1. In the schematic diagram of different embodiments of the groove width shown in FIG. 1 , in the direction in which the groove 131 extends from the edge of the substrate 11 or the layer 12 to the inner side of the edge, that is, in the length direction of the groove 131, the width of the groove 131 can be set to be the same ( Fig.16a ), or the width of the groove 131 at the edge of the substrate 11 or the layer 12 is set to be smaller than the width of the groove 131 inside the edge, so as to form an inverted wedge shape with a narrow outside and a wide inside. Fig.16b ), or it may be wider over part of the length inside the edge ( Fig.16c The inverted wedge-shaped groove 131 with a narrow outside and a wide inside is used to facilitate the post-cast concrete in the groove to form an inverted wedge shape and enhance the anchoring effect. With this type of groove, it is possible to eliminate the post-placed connecting steel bars in the groove and directly realize the connection between prefabrication and cast-in-place by concrete.

[0063] Optional, see Fig.17a and Fig.17bSchematic diagram of different variations of the bottom surface of the groove shown. In the direction in which the groove 131 extends from the edge of the substrate 11 or the layer 12 to the inner side of the edge, that is, in the length direction of the groove 131, the depth of the groove 131 can be set to be the same, or the depth of the groove 131 at the edge of the substrate 11 or the layer 12 is set to be greater than the depth of the groove 131 on the inner side of the edge, that is, the depth of the groove 131 decreases from the outside to the inside. For example, the bottom surface of the groove may include an inclined surface that gradually inclines from the inside to the outside or a stepped surface that changes in a step shape, or may include both an inclined surface and a stepped surface. The effect of reducing the depth of the groove from the outside to the inside is that the length required for the lower connecting steel bar is shorter, while the length of the upper connecting steel bar is longer. In addition, this method can reduce the amount of post-cast concrete on site, and the shallower the groove, the easier it is to demould, and the more convenient it is to produce.

[0064] Optionally, the inner wall of the groove 13 may be set to an uneven surface, for example Fig.11 A schematic diagram of an embodiment of a groove is shown in the figure. In this embodiment, the inner wall of the groove 13 is provided with a corrugated groove 131, so that the inner wall of the groove 13 forms a corrugated surface, so as to increase the contact area with the later poured concrete after pouring concrete in the groove 13, and increase the connection force and firmness. A plurality of pits or a plurality of protrusions can also be provided on the inner wall of the groove 13, as long as the inner wall surface of the groove 13 is formed into an uneven structure, which is not specifically limited here.

[0065] In an optional embodiment of the present disclosure, in order to realize the function of connecting the bottom reinforcement of the plate with the adjacent plate or plate support, the thickness of the base plate 11 is thinned at at least part of the edge (edge ​​for connection) of the base plate 11. This solution can be regarded as one form of opening the groove 13, that is, the edge thinning area of ​​the base plate 11 is regarded as the opened groove 13. The connecting steel bar 5 is placed on the thinned surface of the base plate 11, and the concrete is poured to bury the connecting steel bar 5 therein.

[0066] In an optional embodiment of the present disclosure, see Fig.12 A top view of the connection structure with slab top reinforcement is shown, and Fig.13 The cross-sectional view of the connection structure with the slab top reinforcement is shown. The upper part of the layer plate 12 (the position close to the top of the layer plate 12) can be provided with a slab top reinforcement 4, the upper surface of the reinforcement is close to the top surface of the layer plate 12 to meet the protective layer requirements, and the slab top reinforcement 4 is covered inside the layer plate 12, and does not extend from the side of the layer plate 12, that is, there is no beard reinforcement. The slab top reinforcement 4 is a reinforcement arranged on the upper part of the plate, which mainly bears negative bending moment and prevents the plate surface from cracking. When making the layer plate 12, the slab top reinforcement 4 is first laid in the mold, and then concrete is poured into the mold.

[0067] In an optional embodiment of the present disclosure, at least part of the edge of the layer plate 12 (the edge for connection) is also provided with a groove 13 for placing the connecting steel bar 5, and the groove 13 extends from the edge to the inner side of the edge. In the case of providing the top steel bar 4, the groove 13 needs to avoid the top steel bar 4 to avoid interference between the two, so as to avoid the top steel bar 4 being exposed in the groove 13. The form and setting method of the groove 13 are similar to the groove 13 at the edge of the base plate 11, and will not be repeated here.

[0068] In an optional embodiment of the present disclosure, the area of ​​the layer plate 12 can also be reduced to avoid the placement of the connecting steel bars 5. The connecting steel bars 5 are placed on the base plate 11, the thickness of the base plate 11 is not reduced, and the connecting steel bars 5 are buried therein by pouring concrete.

[0069] That is, different connection methods are formed by different combinations of four methods: opening a groove 13 at the connection edge of the substrate 11 or thinning the edge of the substrate 11 and opening a groove 13 at the connection edge of the layer 12 or reducing the area of ​​the layer 12. Figures 1 to 8 Different embodiments and connection methods shown. Among them, Figure 1 and Figure 2 This is an embodiment in which both the substrate 11 and the layer plate 12 are provided with grooves 13; Figure 3 and Figure 4 This is an embodiment in which the substrate 11 is provided with a groove 13 and the layer 12 has a reduced area; Figure 5 and Figure 6 This is an embodiment in which the edge of the substrate 11 is thinned and the layer plate 12 is provided with a groove 13; Figure 7 and Figure 8 This is an embodiment in which the edge of the substrate 11 is thinned and the area of ​​the layer 12 is reduced. In the specific implementation process, corresponding selections can be made according to actual conditions.

[0070] For example, see Fig. 9 The base plate 11 shown in the figure is a schematic diagram of the connection method of the plates in the form of thin edges. The connecting steel bars 5 are placed on the thinned edges of the two base plates 11, and the concrete is poured until it is flush with the surface of the layer plate 12. Or see Fig.10 The base plate 11 shown is a schematic diagram of the connection method of the plates in the form of grooves. The connecting steel bars 5 are placed in a corresponding group of grooves 13 of the two base plates 11, and concrete is poured until it is flush with the surface of the layer plate 12.

[0071] Optionally, a plurality of grooves 13 may be provided, and the plurality of grooves 13 are arranged at intervals with the bottom steel bar 3 or the top steel bar 4. If the cross-sectional shape of the groove 13 is selected to be rectangular, the width of the groove 13 is in the range of 50 mm to 300 mm, and the width of the concrete teeth between adjacent grooves 13 is in the range of 50 mm to 300 mm.

[0072] In an optional embodiment of the present disclosure, the bottom steel bars 3 or the top steel bars 4 can be formed by a plurality of steel bars arranged in parallel and at intervals in the same horizontal plane, and the directions of the bottom steel bars 3 and the top steel bars 4 can be the same or perpendicular to each other. Optionally, the bottom steel bars 3 and the top steel bars 4 can both be made of steel mesh or one of them can be made of steel mesh and the other can be made of other forms. The steel mesh is a mesh made by crisscrossing longitudinal and transverse steel bars by binding or welding, and is a planar structure. The use of steel mesh can improve the quality of steel engineering, increase construction speed, and enhance the crack resistance of concrete. It is also relatively easy to realize industrial production, and the mesh can be automatically welded into a mesh by a machine and dropped into the prefabricated floor slab formwork by a robot.

[0073] In an optional embodiment of the present disclosure, the substrate 11 is rectangular, and the grooves 131 are evenly spaced in the middle area of ​​the edge of the substrate 11, that is, the four edges of the substrate 11 are provided with a plurality of grooves 131, and the plurality of grooves 131 are distributed along the middle area of ​​each edge, and the extension direction of the grooves 131 is perpendicular to the edge where they are located, and the extension direction of the grooves 131 of one set of opposite edges is perpendicular to the extension direction of the grooves 131 of another set of opposite edges. The four corners of the substrate 11 can be provided with enlarged grooves 132 with a larger coverage area, such as square grooves 132 covering the entire corner area, which is equivalent to thinning the thickness of the four corners of the substrate 11. This arrangement is suitable for boards that are bidirectionally connected, that is, connections are required in two vertical directions. However, the present disclosure is not limited thereto, and the grooves 131 can also be provided only in one set of two opposite edges, that is, opposite sides. This arrangement is suitable for boards that are unidirectionally connected, that is, connections are required only in one direction.

[0074] In an optional embodiment of the present disclosure, the edge of the layer plate 12 is not limited to a straight line, and may include a curved line, such as a broken line or an irregular curve, which is beneficial to increase the contact area between the post-cast concrete and the precast concrete and enhance the bonding effect between the two.

[0075] Optionally, the negative moment steel bars of the support can be avoided by reducing the plane size of the layer plate 12 (e.g., smaller than the length of the negative moment steel bars of the support), simplifying the component production and speeding up the on-site construction. The negative moment steel bars of the support are used to connect the top steel bars 4 of the two superimposed prefabricated floor slabs 1.

[0076] In an optional embodiment of the present disclosure, if the shapes of the base plate 11 and the layer plate 12 are both rectangular, the geometric centers of the base plate 11 and the layer plate 12 coincide, and the distance between the edge of the layer plate 12 and the edge corresponding to its position on the base plate 11 is not less than 1 / 4 of the shorter side length of the base plate 11, so as to meet the requirements for placing the support steel bars.

[0077] In an optional embodiment of the present disclosure, pipelines (not shown in the figure) are pre-buried inside the base plate 11, and the base plate 11 is set to a rectangular shape. The concrete composite prefabricated floor slab is spliced ​​into a whole on site, and the pipelines in each prefabricated slab need to be connected on site. The connection of the pipeline refers to pouring concrete after connecting the pipeline on site, so the connection of the pipeline needs to be carried out in a place where there is post-poured concrete. According to different connection positions, the following two different implementation structures are set.

[0078] The first method: the four corners of the substrate 11 are provided with enlarged grooves 132, which can cover the entire corner area, so that the thickness of the four corners of the substrate 11 is thinned, and the pipelines buried in the substrate 11 extend into the grooves 132 at the four corners of the substrate 11. Since there is post-cast concrete in the grooves 132, connections can be made in the grooves 132 and then concrete is poured.

[0079] The second method: the pipeline buried in the base plate 11 extends out from the side of the base plate 11. Since the beams matching the precast panels have overlapping layer positions and there is post-poured concrete at the overlapping layer positions, the pipeline extending out from the side of the base plate 11 can be connected at the overlapping layer positions and then concrete is poured.

[0080] Optionally, pipelines may be pre-buried inside the layer plate 12 (not shown in the figure), and the layer plate 12 is set to be rectangular, and the connection scheme of its pipelines is similar to the connection scheme of the pipelines pre-buried in the base plate 11. Or the pipelines are connected. . . . . Since the structure of the layer plate 12 and the base plate 11 forms a cast-in-place concrete area, the following three different implementation structures can be formed.

[0081] The first method is that the pipelines embedded in the layer plate 12 extend from the side of the layer plate 12 to the cast-in-place concrete area. Since there is post-cast concrete in the cast-in-place concrete area, the pipelines can be connected in the cast-in-place concrete area and then the concrete is poured.

[0082] The second method: the four corners of the layer plate 12 are provided with enlarged grooves 132, and the grooves 132 can cover the entire corner area, so that the thickness of the four corners of the layer plate 12 is thinned, and the pipelines buried in the layer plate 12 extend into the grooves 132 at the four corners of the layer plate 12. Since there is post-poured concrete in the grooves 132, the pipelines can be connected in the grooves 132 and then the concrete is poured.

[0083] The third method: the pipelines buried in the layer plate 12 extend from the side of the layer plate 12 to the outside of the side of the base plate 11. Since the beams matching the prefabricated panels have overlapping layer positions and there is post-poured concrete at the overlapping layer positions, the pipelines extending out of the side of the base plate 11 can be connected at the overlapping layer positions and then concrete is poured.

[0084] The present disclosure also provides a construction method of a composite prefabricated floor 1, the structure of which includes a base plate 11, a layer plate 12 stacked on the top surface of the base plate 11, and a bottom plate steel bar 3 arranged on the base plate 11. The base plate 11 and the layer plate 12 are both prefabricated with concrete; the area where the layer plate 12 contacts the base plate 11 is smaller than the area of ​​the base plate 11, and the top surface of the layer plate 12 is the finished surface of the floor structure; the bottom plate steel bar 3 is covered inside the base plate 11. The area where the base plate 11 does not contact the layer plate 12 forms a cast-in-place concrete area. The construction method includes:

[0085] The composite prefabricated floor slab 1 is set in place; the composite prefabricated floor slab 1 can be docked with the target component and fixed by means of a hoisting and supporting device.

[0086] The construction method for setting the composite prefabricated floor 1 in place can be to set a vertical support at the bottom of the board. Optionally, angle steel or the like can be directly set on the board support 6, such as a wall or a beam to support the floor, thereby eliminating the need for installation of vertical supports and improving construction efficiency. Fig.14 The schematic diagram shown in the figure shows the use of angle steel supports in the construction of the composite prefabricated floor slab disclosed in the present invention. The composite prefabricated floor slab 1 is supported in the form of angle steel 31, wherein the upper end surface of the angle steel 31 supports the composite prefabricated floor slab 1, and the other end surface of the angle steel 31 is fixedly connected to the plate support 6 by bolts. The support method of the above-mentioned angle steel 31 can avoid the step of installing a large number of vertical supports, thereby reducing labor, improving efficiency and saving construction costs.

[0087] A groove 13 is provided at the edge of the base plate 11 for connection, and a connecting steel bar 5 is placed in the groove 13; and at least a portion of the connecting steel bar 5 is extended out of the groove 13; if a top steel bar 4 is embedded in the layer plate 12, a corresponding groove 13 can also be opened at the connecting edge of the layer plate 12; in this case, a support negative bending moment steel bar 7 needs to be placed in the groove 13.

[0088] The connection steel bars 5 or the support negative moment steel bars 7 may be placed in one groove 13. Fig.18a and Fig.18b The schematic diagram of the arrangement of the connecting steel bars or the negative moment steel bars of the supports in the grooves in the construction method of the composite prefabricated floor slab disclosed in the present invention is shown. During the construction process, at least two connecting steel bars can be placed in the grooves 13 so that the at least two connecting steel bars are arranged at intervals in the same horizontal plane. Fig.18a The example shown is a case where the groove width of the groove 13 is smaller, which is 150 mm to 200 mm. A connecting steel bar is disposed on each of the two sides of the groove 13 . Fig.18bThe groove 13 is shown in the case where the groove width is larger, which is 200mm-250mm. A connecting steel bar is provided on both sides of the groove 13. Similarly, at least two support negative moment steel bars 7 can be placed in the groove 13, so that at least two support negative moment steel bars 7 are arranged at intervals in the same horizontal plane. In the case where the support negative moment steel bars 7 are provided, Fig.18a and Fig.18b It is a top view looking down from the top. Since the connecting steel bars are located directly below the support negative bending moment steel bars 7, they are blocked and not shown. The width of the groove 13 and the setting positions of the two support negative bending moment steel bars 7 are the same as those of the two connecting steel bars.

[0089] Concrete is poured at least in the cast-in-place concrete area and the groove 13, so that the cast-in-place concrete and the composite precast floor slab 1 form an integral load-bearing plate, and the composite precast floor slab 1 is connected to the target component through the connecting steel bars 5 and the poured concrete.

[0090] The height of the poured concrete can be equal to the height of the top surface of the layer plate 12, so that the top surface of the layer plate 12 and the top surface of the poured concrete form an integrated floor structure finished surface.

[0091] Optionally, the height of the concrete poured on site can be made lower than the height of the top surface of the slab 12, and corresponding processing can be performed according to project needs. Subsequently, other processes can be used to make the top surface of the poured concrete and the top surface of the slab 12 form an integrated floor structure finished surface.

[0092] In the description of this specification, the description with reference to the terms "one embodiment / method", "some embodiments / methods", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment / method or example are included in at least one embodiment / method or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment / method or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments / methods or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments / methods or examples described in this specification and the features of the different embodiments / methods or examples, unless they are contradictory.

[0093] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0094] Those skilled in the art should understand that the above embodiments are only for the purpose of clearly illustrating the present disclosure, and are not intended to limit the scope of the present disclosure. For those skilled in the art, other changes or modifications may be made based on the above disclosure, and these changes or modifications are still within the scope of the present disclosure.

Claims

1. A composite prefabricated floor slab, characterized in that: include: A base plate, formed by precast concrete; A layer plate is prefabricated with concrete and formed on the top surface of the base plate, the contact area between the layer plate and the base plate is smaller than the area of ​​the base plate, and the top surface of the layer plate is the finished surface of the floor structure; and a slab bottom reinforcement, the slab bottom reinforcement being arranged on the base plate and covered inside the base plate; Wherein, the area where the base plate is not in contact with the layer plate forms a cast-in-place concrete area; The layer plate is provided with a plate top steel bar, and the plate top steel bar is covered inside the layer plate and does not protrude from the side of the layer plate.

2. The composite prefabricated floor slab according to claim 1, characterized in that: At least part of the edge of the base plate is provided with a groove for placing the connecting steel bars, and the groove extends from the edge to the inner side of the edge.

3. The composite prefabricated floor slab according to claim 2, characterized in that: At least part of the edge of the layer plate is provided with the groove for placing the connecting steel bar, and the groove extends from the edge to the inner side of the edge.

4. The composite prefabricated floor slab according to claim 2, characterized in that: The slab bottom steel bars and / or the slab top steel bars are steel meshes.

5. The composite prefabricated floor slab according to any one of claims 2 to 4, characterized in that: The thickness of the substrate at the bottom of the groove ranges from 20 mm to 60 mm; The total thickness of the substrate and the layer is not less than 80 mm.

6. The composite prefabricated floor slab according to any one of claims 2 to 4, characterized in that: The cross-sectional shape of the groove is rectangular, trapezoidal, V-shaped, semicircular or door-shaped.

7. The composite prefabricated floor slab according to claim 2, characterized in that: The inner wall of the groove is configured as an uneven surface.

8. The composite prefabricated floor slab according to claim 7, characterized in that: The inner wall of the groove is provided with corrugated grooves to form the uneven surface.

9. The composite prefabricated floor slab according to any one of claims 2 to 4, characterized in that: In the direction in which the groove extends from the edge where the groove is located to the inner side of the edge where the groove is located, the width of the groove is the same or the width of the groove increases to form a shape that is narrow outside and wide inside.

10. The composite prefabricated floor slab according to any one of claims 2 to 4, characterized in that: In a direction in which the groove extends from the edge where the groove is located toward the inner side of the edge where the groove is located, the depth of the groove is the same or the depth of the groove decreases.

11. The composite prefabricated floor slab according to claim 10, characterized in that: The bottom surface of the groove includes an inclined surface and / or a stepped surface.

12. The composite prefabricated floor slab according to any one of claims 1 to 4, characterized in that: The base plate is pre-buried with pipelines, and the base plate is rectangular; the four corners of the base plate are provided with enlarged grooves, and the pipelines extend into the enlarged grooves for connection; or the pipelines extend from the side of the base plate for connection.

13. The composite prefabricated floor slab according to any one of claims 1 to 4, characterized in that: Pipelines are pre-buried inside the layer plate, and the layer plate is rectangular; the pipelines extend into the cast-in-place concrete area for connection; or enlarged grooves are provided at the four corners of the layer plate, and the pipelines extend into the enlarged grooves for connection; or the pipelines extend to the outside of the side of the base plate for connection.

14. A construction method for a composite prefabricated floor slab as claimed in claim 1, characterized in that: include: The composite prefabricated floor slab is set in place; a groove is set at the edge of the base plate for connection, and a connecting steel bar is placed in the groove; and concrete is poured at least in the concrete cast-in-place area and the groove.

15. The construction method of composite prefabricated floor slab according to claim 14, characterized in that: At least two connecting steel bars are placed in the groove so that at least two connecting steel bars are arranged at intervals in the same horizontal plane; or at least two support negative moment steel bars are placed in the groove so that at least two support negative moment steel bars are arranged at intervals in the same horizontal plane.

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