Prefabricated concrete sandwich wallboard and bending bearing capacity calculation method

Abstract

The application relates to the field of fabricated buildings, in particular to a fabricated concrete sandwich wallboard and a bending bearing capacity calculation method, which comprises a concrete inner leaf plate, a heat preservation plate and a concrete outer leaf plate which are sequentially and layerwisely arranged from bottom to top. The concrete outer leaf plate and the concrete inner leaf plate are internally embedded with a grid plate which is arranged in parallel with the surface of the heat preservation plate. The heat preservation plate is internally arranged with a pull-tie pipe along the plate length direction. The pull-tie pipe comprises two groups of vertically arranged vertical end plates and two groups of horizontally arranged horizontal end plates. The vertical end plates and the horizontal end plates are enclosed to form a square tube type cavity structure. The surfaces of the two horizontal end plates are provided with edge rib plates. The heat preservation plate is pulled together with the concrete outer leaf plate and the concrete inner leaf plate through the edge rib plates on the pull-tie pipe. The application meets the stress performance requirements of the sandwich wallboard, avoids the generation of the thermal bridge effect, and realizes the lightweight of the wallboard.

Description

Technical Field

[0001] This invention relates to the field of prefabricated buildings, specifically to a prefabricated concrete sandwich wall panel and a method for calculating its flexural bearing capacity. Background Technology

[0002] Precast concrete sandwich insulated wall panels, as a new type of precast reinforced concrete wall panel integrating load-bearing and thermal insulation, are widely used in building exterior or interior walls. Currently available precast concrete sandwich insulated wall panels, as described in patent number "CN210713502U", include an outer leaf panel, an insulation layer, an inner leaf panel, and tie rods; wherein both the outer and inner leaf panels are made of reinforced concrete, the insulation layer is placed between the inner and outer leaf panels, and the tie rods combine the inner and outer reinforced concrete leaf panels and the insulation layer into a single unit.

[0003] Currently, the tie rods in traditional sandwich insulated walls are cast-in-place concrete ribs between the inner and outer concrete leaf plates. While sandwich wall panels using this type of tie rod have good load-bearing performance, the high thermal conductivity of concrete easily leads to significant thermal bridging. To avoid thermal bridging, some sandwich wall panels have evolved from cast-in-place concrete ribs to composite material tie rods. However, conventional composite material tie rods are usually rod-shaped or plate-shaped, with low shear strength and stiffness. This necessitates increasing the thickness of the outer and inner leaf plates in the sandwich wall panel to meet design requirements. Although this avoids thermal bridging, it fails to meet the lightweight requirements of sandwich wall panels, thus requiring a solution. Summary of the Invention

[0004] To avoid and overcome the technical problems existing in the prior art, this invention provides a prefabricated concrete sandwich wall panel and a method for calculating its flexural bearing capacity. This invention meets the stress performance requirements of the sandwich wall panel while avoiding thermal bridging effects and achieving lightweight design.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A prefabricated concrete sandwich wall panel includes an inner concrete leaf panel, an insulation board, and an outer concrete leaf panel arranged sequentially from bottom to top. A grid panel parallel to the surface of the insulation board is embedded within the outer and inner concrete leaf panels. A tie pipe is arranged along the length of the insulation board within the insulation board. The tie pipe includes two sets of parallel vertical end plates and two sets of parallel horizontal end plates. The vertical and horizontal end plates enclose a square tube-shaped cavity structure. Edge ribs are provided on the surfaces of the two horizontal end plates. The insulation board is connected to the outer and inner concrete leaf panels via the edge ribs on the tie pipe.

[0007] As a further aspect of the present invention: the grid plate includes cross-shaped horizontal limbs and vertical limbs, and the edge ribs are arranged along the symmetry line of the horizontal end plate and connected to one of the vertical limbs of the grid plate.

[0008] As a further embodiment of the present invention: the tie tubes are evenly distributed horizontally within the insulation board, and the distance between adjacent tie tubes is S, where 500mm≤S≤700mm.

[0009] As a further embodiment of the present invention: the wall thickness of the vertical end plate, the horizontal end plate and the edge rib plate is D, where 5mm≤D≤10mm.

[0010] As a further aspect of the present invention: the thickness of the inner concrete leaf plate and the outer concrete leaf plate is H, where 30mm≤H≤50mm.

[0011] As a further aspect of the present invention: the insulation board is made of extruded polystyrene.

[0012] As a further aspect of the present invention: the tensile strength of the grid plate is 1400MPa, and the compressive strength of the outer concrete leaf plate and the inner concrete leaf plate is 120MPa.

[0013] A method for calculating the flexural bearing capacity of a prefabricated concrete sandwich wall panel, wherein the ultimate flexural bearing capacity of the prefabricated concrete sandwich wall panel is M. u :

[0014]

[0015] Among them, f u The longitudinal tensile strength of the grid plate;

[0016] A f This represents the total cross-sectional area of ​​the longitudinal limbs of the grid plate;

[0017] h0 is the effective height of the sandwich wall panel;

[0018] x represents the relative height of the compression zone of the sandwich wall panel;

[0019] This is a correction factor;

[0020] x1 is the wall thickness of the vertical end plate, the horizontal end plate, and the edge ribs;

[0021] x2 is the cross-sectional length of the edge rib;

[0022] x3 is the cross-sectional length of the transverse end plate.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] 1. The cross-section of the tie member of the present invention is designed as a "middle" shape, with a cavity inside, effectively increasing the heat transfer path and further reducing the thermal bridge effect. By replacing the traditional steel bar structure with a composite material grid plate, while meeting the design bearing capacity of the sandwich wall panel, the thickness of the inner concrete leaf and the outer concrete leaf can be effectively reduced, making the sandwich wall panel lighter.

[0025] 2. The present invention uses ultra-high performance concrete to make the tie member, which is integrally formed with the inner concrete leaf and the outer concrete leaf of the ultra-high performance concrete, without the need for the anchorage length of the tie member; since a composite material grid is used to replace the steel bar, there is no hidden danger of steel bar corrosion. At the same time, ultra-high performance concrete tie members are used, so the thickness of the upper and lower leaves can be greatly reduced, forming a lightweight component.

[0026] 3. The present invention establishes a calculation formula for the ultimate flexural bearing capacity of the sandwich wall panel adapted to the "middle" - shaped tie member, which can quickly calculate the ultimate flexural bearing capacity of the sandwich wall panel under different working conditions and is in good agreement with the actual results. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic structural diagram of the present invention.

[0028] Figure 2 It is a simulation nephogram of the bending state of the present invention.

[0029] Figure 3 It is a data comparison and analysis chart of the calculated value and the simulated value of the flexural bearing capacity of the present invention.

[0030] In the figure:

[0031] 1. Inner concrete leaf; 2. Insulation board; 3. Outer concrete leaf; 4. Grid board;

[0032] 5. Tie pipe; 51. Vertical end plate; 52. Horizontal end plate; 53. Edge rib plate. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0034] Please refer to Figures 1-3, in the embodiments of the present invention, a precast concrete sandwich wall panel and a calculation method for its flexural bearing capacity include a concrete inner leaf panel 1, a thermal insulation panel 2, and a concrete outer leaf panel 3 arranged in layers from bottom to top. Both the concrete inner leaf panel 1 and the concrete outer leaf panel 3 are ultra-high performance concrete (UHPC). The thermal insulation panel 2 is an extruded polystyrene thermal insulation panel. Grid plates 4 are provided in both the concrete inner leaf panel 1 and the concrete outer leaf panel 3. The thicknesses of the concrete inner leaf panel 1 and the concrete outer leaf panel 3 are H, where 30 mm ≤ H ≤ 50 mm.

[0035] A groove body with a "zhong" - shaped cross - section is pre - formed in the thermal insulation panel 2 for inserting a tie pipe 5. The tie pipe 5 can be inserted into the thermal insulation panel 2 after pre - processing, or formed in the thermal insulation panel 2 by pouring. The tie pipes 5 are horizontally and evenly spaced in the thermal insulation panel 2. The spacing S between two adjacent groups of tie pipes 5 is 500 mm ≤ S ≤ 700 mm, preferably 600 mm.

[0036] The sandwich wall panel is integrally cast. During processing, first, one group of grid plates 4 is tied with cushion blocks and placed into a template to pour the concrete inner leaf panel 1. Then, the thermal insulation panel 2 is placed into the template. Finally, the other group of grid plates 4 is tied with cushion blocks and placed on the thermal insulation panel 2, and then the concrete outer leaf panel 3 and the tie pipes 5 are poured. After curing, it can be applied to precast buildings.

[0037] The tie pipe 5 includes two groups of parallel vertical end plates 51 and two groups of parallel horizontal end plates 52. The vertical end plates 51 and the horizontal end plates 52 enclose a hollow square pipe. An edge rib 53 is arranged on the central axis of the horizontal end plate 52, and the edge rib 53 is arranged parallel to the plate surface of the vertical end plate 51. The wall thicknesses of the vertical end plate 51, the horizontal end plate 52, and the edge rib 53 are D, where 5 mm ≤ D ≤ 10 mm.

[0038] The grid plate 4 includes transverse limbs and longitudinal limbs arranged in a cross - intersection manner. Each longitudinal limb is arranged parallel to the tie pipe 5, and one of the longitudinal limbs is connected to the edge rib 53 of the tie pipe 5.

[0039] Due to the change of the tie member, the flexural bearing capacity calculation formula in the current specification is no longer applicable to the calculation of the ultimate flexural bearing capacity of the sandwich wall panel in this application.

[0040] The ultimate flexural bearing capacity of this sandwich wall panel is M u :

[0041]

[0042] where, f u is the tensile strength of the longitudinal limb of the grid plate 4;

[0043] A f is the total cross - sectional area of the longitudinal limbs of the grid plate 4;

[0044] h0 is the effective height of the sandwich wall panel;

[0045] x represents the relative height of the compression zone of the sandwich wall panel;

[0046] This is a correction factor;

[0047] x1 is the wall thickness of the vertical end plate 51, the horizontal end plate 52, and the edge rib plate 53;

[0048] x2 is the cross-sectional length of the edge rib 53;

[0049] x3 is the cross-sectional length of the transverse end plate 52.

[0050] according to Figure 3 As shown, the vertical axis represents the calculated flexural bearing capacity of the sandwich wall panel in this application, and the horizontal axis represents the simulated flexural bearing capacity of the sandwich wall panel. It can be seen that the calculated flexural bearing capacity of this application is basically consistent with the simulated value.

[0051] A numerical model of the sandwich wall panel in this application was established using the nonlinear finite element software ABAQUS. The ultra-high performance concrete was modeled as a three-dimensional solid model, and the mesh was created using three-dimensional truss elements. The inner concrete leaf plate 1 and the outer concrete leaf plate 3 have a thickness of 30 mm, a length of 2400 mm, and a width of 1000 mm. The cross-sectional area of ​​the transverse and longitudinal limbs of the two sets of mesh plates is 20 mm². 2 The overall thickness of the sandwich wall panel is 150mm, and the spacing between two adjacent tie pipes 5 inside the insulation board 2 is 600mm. The grid plate 4 is a basalt fiber composite material grid with a tensile strength of 1400MPa, and the compressive strength of the inner concrete leaf plate 1 and the outer concrete leaf plate 3 is 120MPa.

[0052] Under the above working conditions, the wall thickness x1 of the vertical end plate 51, the horizontal end plate 52 and the edge rib plate 53 is taken as 6mm or 8mm; the cross-sectional length x2 of the edge rib plate 53 is taken as 15mm or 20mm or 25mm; and the cross-sectional length x3 of the horizontal end plate 52 is taken as 35mm, 40mm and 45mm. There are 18 working conditions with the above parameters. The numerical simulation and analysis results corresponding to each working condition are shown in Table 1 below.

[0053] Table 1

[0054] serial number <![CDATA[x1]]> <![CDATA[x2]]> <![CDATA[x3]]> <![CDATA[M test ]]> <![CDATA[M u ]]> <![CDATA[M u / M test ]]> 6-15-35 6 15 35 24.06 24.49 1.017 6-15-40 6 15 40 23.12 23.43 1.013 6-15-45 6 15 45 22.23 22.37 1.007 6-20-35 6 20 35 23.71 23.78 1.003 6-20-40 6 20 40 22.79 22.73 0.997 6-20-45 6 20 45 21.91 21.67 0.989 6-25-35 6 25 35 23.21 23.08 0.994 6-25-40 6 25 40 22.31 22.02 0.987 6-25-45 6 25 45 21.51 20.97 0.975 8-15-35 8 15 35 27.87 27.86 1.000 8-15-40 8 15 40 26.71 26.81 1.004 8-15-45 8 15 45 26.19 25.75 0.983 8-20-35 8 20 35 27.49 27.16 0.988 8-20-40 8 20 40 26.34 26.10 0.991 8-20-45 8 20 45 25.83 25.05 0.970 8-25-35 8 25 35 26.74 26.46 0.989 8-25-40 8 25 40 25.68 25.40 0.989 8-25-45 8 25 45 22.56 24.34 1.079

[0055] In Table 1, M test The ultimate flexural bearing capacity of the wall panel is obtained through software simulation analysis (unit: kN*m); M u The ultimate flexural bearing capacity of the wall panel is calculated using the formula for ultimate flexural bearing capacity of this application; through M under various working conditions uand M test The ratio shows that the calculated ultimate flexural bearing capacity of the wall panel obtained in this application has a very low error compared with the simulation results.

[0056] like Figure 2 As shown, under bending conditions, the deformation of the sandwich wall panel of the present invention exhibits a relatively continuous gradient with clear layering, reasonable stress distribution, good collaborative working ability, and excellent overall performance.

[0057] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0058] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

Claims

1. A method for calculating the flexural bearing capacity of prefabricated concrete sandwich wall panels, characterized in that, The prefabricated concrete sandwich wall panel includes an inner concrete leaf panel (1), an insulation board (2), and an outer concrete leaf panel (3) arranged sequentially from bottom to top. The outer concrete leaf panel (3) and the inner concrete leaf panel (1) are embedded with a grid plate (4) arranged parallel to the surface of the insulation board (2). A tie pipe (5) is arranged along the length of the insulation board (2). The length of the tie pipe (5) is consistent with the length of the sandwich wall panel. The tie pipe (5) includes two sets of parallel vertical end plates (51) and two sets of parallel horizontal end plates (52). The vertical end plates (51) and the horizontal end plates (52) enclose a square tube cavity structure. Edge ribs (53) are provided on the surface of the two horizontal end plates (52). The insulation board (2) is tied to the outer concrete leaf panel (3) and the inner concrete leaf panel (1) through the edge ribs (53) on the tie pipe (5). The ultimate flexural bearing capacity of prefabricated concrete sandwich wall panels is M. u : Among them, f u The longitudinal tensile strength of the grid plate (4); A f The total cross-sectional area of ​​the longitudinal limbs of the grid plate (4); h0 is the effective height of the sandwich wall panel; x represents the relative height of the compression zone of the sandwich wall panel; This is a correction factor; x1 is the wall thickness of the vertical end plate (51), the horizontal end plate (52), and the edge rib plate (53); x2 is the cross-sectional length of the edge rib (53); x3 is the cross-sectional length of the transverse end plate (52).

2. The method for calculating the flexural bearing capacity of a prefabricated concrete sandwich wall panel according to claim 1, characterized in that, The grid plate (4) includes cross-shaped horizontal limbs and vertical limbs, and the edge ribs (53) are arranged along the symmetry line of the horizontal end plate (52) and connected to one of the vertical limbs of the grid plate (4).

3. The method for calculating the flexural bearing capacity of a prefabricated concrete sandwich wall panel according to claim 1 or 2, characterized in that, The tie tubes (5) are evenly distributed in the horizontal direction within the insulation board (2), and the distance between adjacent tie tubes (5) is S, 500mm≤S≤700mm.

4. The method for calculating the flexural bearing capacity of a prefabricated concrete sandwich wall panel according to claim 1 or 2, characterized in that, The wall thickness of the vertical end plate (51), horizontal end plate (52) and edge rib plate (53) is D, where 5mm≤D≤10mm.

5. A method for calculating the flexural bearing capacity of a prefabricated concrete sandwich wall panel according to claim 1 or 2, characterized in that, The thickness of the inner concrete leaf plate (1) and the outer concrete leaf plate (3) is H, 30mm≤H≤50mm.

6. The method for calculating the flexural bearing capacity of a prefabricated concrete sandwich wall panel according to claim 1 or 2, characterized in that, The insulation board (2) is made of extruded polystyrene.

7. The method for calculating the flexural bearing capacity of a prefabricated concrete sandwich wall panel according to claim 1 or 2, characterized in that, The tensile strength of the grid plate (4) is 1400MPa, and the compressive strength of the concrete outer leaf plate (3) and the concrete inner leaf plate (1) is 120MPa.

Images