Orthogonal laminated wood or bamboo board-concrete bidirectional composite floor, manufacturing method and calculation method of hole and self-tapping screw number

Abstract

The application provides a kind of orthogonal glued wood or bamboo board-concrete bidirectional composite floor, manufacturing method and the calculation method of hole and self-tapping screw quantity, and the composite floor includes orthogonal glued wood or bamboo board, concrete, reinforcing steel, self-tapping screw and hole.The wood fiber or bamboo fiber of the lower surface of orthogonal glued wood or bamboo board is arranged along the short span direction of bidirectional board, at least one row of holes is provided on the upper surface of orthogonal glued wood or bamboo board, a plurality of self-tapping screws are drilled into the upper surface of orthogonal glued wood or bamboo board, bidirectional reinforcing steel is laid on the upper surface of orthogonal glued wood or bamboo board, and concrete is poured on the upper surface of orthogonal glued wood or bamboo board to fill the holes and completely cover the reinforcing steel and self-tapping screws.The application can significantly improve the bending stiffness and ultimate bearing capacity of orthogonal glued bamboo (wood) bidirectional board, ensure the good cooperative working performance of concrete and orthogonal glued bamboo (wood), and comprehensively improve the wind resistance and vibration comfort of orthogonal glued bamboo (wood) structure.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of civil engineering, in particular to a kind of orthogonal glued wood or bamboo board-concrete bidirectional composite floor, and the manufacturing method of the composite floor, and the calculation method of the number of holes and self-tapping screw in the composite floor. BACKGROUND

[0002] Orthogonal glued board is a kind of engineering bamboo product made of three or more than three layers of sawn timber or structural composite laminates vertically orthogonal assembly, which is glued with structural adhesive or connected with metal parts. This kind of product has many advantages such as beautiful appearance, low carbon environmental protection and easy construction, and has been widely used in wood structure or bamboo structure building. However, the self-weight of wood or bamboo is relatively light, which will reduce the vibration comfort of orthogonal glued bamboo (wood) floor. At present, the orthogonal glued wood or bamboo-concrete composite floor is mostly unidirectional, and less involves the bidirectional collaborative stress performance of concrete and orthogonal glued wood or bamboo. Therefore, it is necessary to take corresponding technical measures to improve the vibration comfort of orthogonal glued bamboo floor and develop orthogonal glued wood or bamboo-concrete bidirectional composite floor. SUMMARY

[0003] The present application provides a kind of orthogonal glued wood or bamboo-concrete bidirectional composite floor, the floor includes orthogonal glued wood or bamboo board, concrete, reinforcing steel, self-tapping screw and hole;

[0004] Orthogonal glued wood or bamboo board is rectangular board with different length and width, and the wood fiber or bamboo fiber on the lower surface of the orthogonal glued wood or bamboo board is arranged along the short span direction of the bidirectional board,

[0005] At least one row of holes is provided on the upper surface of the orthogonal glued wood or bamboo board, a plurality of self-tapping screws are drilled into the upper surface of the orthogonal glued wood or bamboo board (the self-tapping screws are not drilled into the holes), bidirectional reinforcing steel is laid on the upper surface of the orthogonal glued wood or bamboo board, and the concrete is poured on the upper surface of the orthogonal glued wood or bamboo board to fill the holes and completely cover the reinforcing steel and self-tapping screws.

[0006] Further, a row of circular holes is provided on the upper surface of the orthogonal glued wood or bamboo board along the long span and short span directions of the bidirectional board, and each row of holes is arranged at the edge of the orthogonal glued wood or bamboo board with equal spacing.

[0007] The depth of the hole is the thickness of the single-layer board of the orthogonal glued wood or bamboo board, and the spacing can be determined according to the size of the bidirectional board, and the center-to-center spacing of the holes is not less than 2 times the diameter of the hole.

[0008] Further, the angle between the self-tapping screw and the orthogonal glued wood or bamboo board in the thickness direction of the board is 45°-90°.

[0009] The drilling directions of the self-tapping screws on the two sides of the long-span direction of the orthogonal glued wood or bamboo board are arranged in the plastic strand direction, and a plurality of rows of self-tapping screws with the drilling directions arranged in the short-span direction are arranged in the middle of the span.

[0010] Further, the two arrangement directions of the steel bars are consistent with the long-span and short-span directions of the orthogonal glued wood or bamboo board.

[0011] A manufacturing method of a composite floor slab, comprising the following steps:

[0012] S1, determining the tensile plastic strand of the orthogonal glued wood or bamboo board according to the reinforced concrete slab theory, drilling holes on the upper surface of the orthogonal glued wood or bamboo board and drilling self-tapping screws;

[0013] S2, fixing the two-way steel bars on the upper surface of the orthogonal glued wood or bamboo board through the fixing device;

[0014] S3, pouring concrete on the upper surface of the orthogonal glued wood or bamboo board, filling the holes and completely covering the steel bars and self-tapping screws.

[0015] In the above manufacturing method, the number of holes and the number of self-tapping screws are determined according to the following steps:

[0016] Step S11: determining the design value of the uniform load of the two-way board according to the design working condition of the floor slab;

[0017] Step S12: determining the bending moment M l and M s borne by the long-span and short-span of the two-way board respectively according to the two-way board design manual;

[0018] Step S13: determining the bending stiffness EI l and EI s of the long-span and short-span of the two-way board respectively;

[0019] Step S14: iteratively solving to determine the number of holes and the number of self-tapping screws in the long-span and short-span directions of the two-way board according to the slip stiffness and shear bearing capacity of a single hole and the slip stiffness and shear bearing capacity of a single self-tapping screw.

[0020] Further, the calculation process of step S13 is as follows:

[0021] S13a, the bending stiffness expression of the long-span and short-span of the two-way board is:

[0022]

[0023] In formula 1: E1 and E2 are the elastic moduli of concrete and the orthogonal glued wood or bamboo board respectively; I l1 and I s1 are the moments of inertia of the long-span and short-span of the concrete respectively; rl1 and r s1 are the connection coefficients of the long-span direction and the short-span direction of the orthogonal glulam or bamboo panel, respectively; A l1 and A s1 are the equivalent cross-sectional areas of the long-span direction and the short-span direction of the orthogonal glulam or bamboo panel (when simplified, the cross-sectional area of the wood or bamboo in the longitudinal direction can be taken as the equivalent cross-sectional area, and the influence of the transverse direction of the wood or bamboo can be ignored); a l1 and a s1 are the distances between the centroid of the long-span direction and the short-span direction of the orthogonal glulam or bamboo panel and the centroid of the composite section;

[0024] S13b, the expression of the distance between the centroid of the long-span direction and the short-span direction of the orthogonal glulam or bamboo panel and the centroid of the composite section is:

[0025]

[0026] In formula 2, h1 is the thickness of the concrete, h l2 and h s2 are the equivalent heights of the long-span direction and the short-span direction of the orthogonal glulam or bamboo panel;

[0027] S13c, the expression of the connection coefficient is:

[0028]

[0029] In formula 3, s l1 and s s1 are the spacing of the self-tapping screws in the long-span direction and the short-span direction of the orthogonal glulam or bamboo panel; K l1 and K l2 are the slip stiffnesses of the long-span direction and the short-span direction of the orthogonal glulam or bamboo panel; L1 and L2 are the spans of the long-span direction and the short-span direction of the orthogonal glulam or bamboo panel;

[0030] S13d, the expression of the slip stiffness of the long-span direction and the short-span direction of the orthogonal glulam or bamboo panel is:

[0031]

[0032] In formula 4, n ls and n ss are the number of self-tapping screws in the long-span direction and the short-span direction of the orthogonal glulam or bamboo panel; K ls and K ss are the slip stiffnesses of a single self-tapping screw in the long-span direction and the short-span direction of the orthogonal glulam or bamboo panel; n ls and n ss are the number of holes in the long-span direction and the short-span direction of the orthogonal glulam or bamboo panel; K lc and K scSlip stiffness of single hole in long span direction and short span direction of orthogonal laminated bamboo or wood board

[0033] The expression of slip stiffness of single self-tapping screw in long span direction and short span direction of orthogonal laminated bamboo or wood board is

[0034]

[0035] In formula 5, ρ is the density of bamboo or wood in orthogonal laminated bamboo or wood board, d is the diameter of self-tapping screw (usually 6-10 mm), β is the angle between self-tapping screw and the grain direction of bamboo or wood, is the angle between self-tapping screw and long span direction;

[0036] The slip stiffness of single hole is taken as n times of the slip stiffness of single self-tapping screw in the direction, and n is usually 10.

[0037] Further, the calculation process of step S14 is as follows:

[0038] S14a, the shear bearing capacity of single self-tapping screw in long span direction and short span direction of orthogonal laminated bamboo or wood board is

[0039]

[0040] In formula 6, δ is the ratio of compressive strength of concrete to bearing pressure strength of self-tapping screw pin, f h,β is the bearing pressure strength of self-tapping screw pin, M y is the bending strength of self-tapping screw;

[0041] S14b, the shear bearing capacity of single hole in long span direction and short span direction of orthogonal laminated bamboo or wood board is

[0042]

[0043] In formula 7, fcv is the shear strength of concrete, and dc is the diameter of hole;

[0044] S14c, the shear bearing capacity of long span direction and short span direction of orthogonal laminated bamboo or wood board is

[0045]

[0046] S14d, the shear force of long span direction and short span direction of orthogonal laminated bamboo or wood board is

[0047]

[0048] In formula 9, μ1 and μ2 are the bending moment to shear force ratio of long span direction and short span direction of orthogonal laminated bamboo or wood board, and L1 and L2 are the span of long span direction and short span direction of orthogonal laminated bamboo or wood board;

[0049] S14e. First, assume that the number of holes in the long direction is 1, the number of self-tapping screws is 2, the angle between the self-tapping screw and the bamboo grain direction and the long span direction is 45°, and the hole diameter is 5 to 15 times the diameter of the self-tapping screw. Calculate the sliding stiffness in the long span direction, and then calculate the interlayer shear force and shear bearing capacity in the long span direction. If the shear bearing capacity is greater than the interlayer shear force, the self-tapping screws and holes in this direction are arranged as assumed; if the shear bearing capacity is less than the interlayer shear force, the number of holes should be increased while ensuring the hole spacing (the center-to-center spacing of the holes should not be less than 2 times the hole diameter). When the number of holes on one side exceeds one row, the holes should be arranged in one row, and the excess holes should be replaced by self-tapping screws.

[0050] The number of holes and self-tapping screws in the short span direction are calculated using the same method.

[0051] In order to ensure that the direction of the plastic strand is not damaged, the self-tapping screws are finally arranged obliquely in the direction of the plastic strand. The number and geometric dimensions of the self-tapping screws refer to the arrangement of the self-tapping screws in the short span direction.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] The cross-laminated timber or bamboo-concrete two-way composite floor slab provided by the present invention has a simple structure and is easy to construct, facilitating widespread project deployment. Furthermore, the composite floor slab prepared according to the present invention employs a specific calculation method to determine the number of holes and self-tapping screws. This significantly improves the flexural stiffness and ultimate bearing capacity of the cross-laminated bamboo (timber) two-way slab, ensuring good synergy between concrete and cross-laminated bamboo (timber), preventing premature cracking and damage to concrete due to stress concentration, and comprehensively enhancing the wind resistance and vibration comfort of the cross-laminated bamboo (timber) structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0055] Figure 1 A cross-sectional view of a two-way composite floor slab of cross-laminated timber or bamboo board and concrete provided in one embodiment of the present invention;

[0056] Figure 2 Layout drawings of cross-section steel bars and bamboo;

[0057] Figure 3 Detailed drawing of the interface between cross-laminated timber or bamboo panels and concrete from a top-down perspective;

[0058] Figure 4 For Figure 3 the cross-sectional view in the A-A direction;

[0059] Figure 5 For Figure 3 the cross-sectional view in the B-B direction;

[0060] Figure 6 For Figure 3 the cross-sectional view in the C-C direction. DETAILED DESCRIPTION

[0061] In the following description, numerous specific details are set forth to provide a more thorough understanding of the present application. However, it will be apparent to one of skill in the art that the present application can be practiced without one or more of these specific details. In other instances, well-known features have not been described in order to avoid obscuring the present application.

[0062] For a thorough understanding of the present application, reference should be made to the following detailed description taken in conjunction with the accompanying drawings, in which:

[0063] Example One

[0064] As Figures 1 to 6 shown in the present embodiment, a design and fabrication method of orthogonal glued bamboo-concrete bidirectional composite floor slab is provided, including orthogonal glued bamboo, concrete 2, steel bar 3, self-tapping screw 4 and cylindrical hole 5. Figure 3 In the figure, the circle represents the hole 5, and the short solid line represents the self-tapping screw 4. The bamboo fiber on the lower surface of the orthogonal glued bamboo is arranged along the short span direction of the bidirectional slab. The dimensional lumber of the orthogonal glued bamboo is arranged in three layers, with a thickness of 35 mm for each layer. Cylindrical holes 5 are arranged on the upper surface of the orthogonal glued bamboo along the long span and short span directions of the bidirectional slab, respectively. The hole geometry is determined according to the calculation results. The hole 5 is arranged 500 mm away from the slab edge, with a depth, diameter and center distance of 35 mm, 200 mm and 400 mm, respectively. The number of holes in the long span and short span directions is 6 and 10, respectively. The orthogonal glued bamboo bidirectional slab is determined according to the theory of reinforced concrete slab, and the tensile plastic strand is arranged on the upper surface of the orthogonal glued bamboo. The self-tapping screw 4 is drilled into the orthogonal glued bamboo, and the angle between the self-tapping screw 4 and the surface of the slab in the thickness direction of the slab is 45°. The drilling direction of the self-tapping screw 4 on both sides of the slab is arranged in a cross direction along the plastic strand direction (as shown by the two solid arrows on the left side of the figure); the drilling direction of the self-tapping screw 4 in the middle of the span is arranged in a cross direction along the short span direction (as shown by the two solid arrows on the right side of the figure). Figure 3 The two solid arrows on the left side of the figure show the drilling direction of the self-tapping screw 4 on both sides of the slab, which is arranged in a cross direction along the plastic strand direction. Figure 3The diameter, length and center distance of the self-tapping screw 4 are 8mm, 120mm and 200mm respectively. The self-tapping screw 4 is arranged in 9 rows in the short-span direction, and the number of the self-tapping screw 4 in each row is 6. The diameter, length and center distance of the self-tapping screw 4 in the diagonal plastic hinge line direction are the same as those in the short-span direction, but the drilling direction is consistent with the plastic hinge line direction. The steel bars 3 with a bidirectional diameter of 8mm and a distance of 200mm are fixed on the upper surface of the orthogonal laminated bamboo by the fixing device. The thickness of the protective layer of the steel bars 3 is 15mm. The concrete 2 is poured on the upper surface of the orthogonal laminated bamboo. The cylindrical hole 5 needs to be filled with the concrete 2, and the steel bars 3 and the self-tapping screw 4 need to be completely covered.

[0065] The present application can significantly improve the bending stiffness and ultimate bearing capacity of the orthogonal laminated bamboo bidirectional plate, ensure the good cooperative working performance of the concrete and the orthogonal laminated bamboo, avoid the premature cracking and damage of the concrete due to stress concentration, and comprehensively improve the wind resistance performance and vibration comfort of the orthogonal laminated bamboo structure.

[0066] The above describes the preferred embodiments of the present application. It should be understood that the present application is not limited to the above specific embodiments, and the devices and structures not described in detail should be understood as being implemented in the ordinary way in the art; any person skilled in the art can make many possible changes and modifications to the technical solutions of the present application or modify them into equivalent embodiments with equivalent changes without departing from the scope of the technical solutions of the present application, which does not affect the essential content of the present application. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application without departing from the content of the technical solutions of the present application still belongs to the protection scope of the technical solutions of the present application.

Claims

1. A method of manufacturing a cross-laminated timber or bamboo-concrete bidirectional composite floor slab, characterized in that, The floor comprises orthogonal laminated wood or bamboo board (1), concrete (2), steel bar (3), self-tapping screw (4) and hole (5); The orthogonal laminated wood or bamboo board (1) is a rectangular board with different length and width, and the wood fibers or bamboo fibers on the lower surface of the orthogonal laminated wood or bamboo board (1) are arranged along the short span direction of the two-way board, At least one row of holes (5) is arranged on the upper surface of the orthogonal laminated wood or bamboo board (1), a plurality of self-tapping screws (4) are drilled on the upper surface of the orthogonal laminated wood or bamboo board (1), the self-tapping screws are not drilled in the holes, two-way steel bars (3) are laid on the upper surface of the orthogonal laminated wood or bamboo board (1), and the concrete (2) is poured on the upper surface of the orthogonal laminated wood or bamboo board (1) to fill the holes (5) and completely cover the steel bars (3) and the self-tapping screws (4); The manufacturing method comprises the following steps: S1. Drill holes (5) on the upper surface of the cross-laminated timber or bamboo board (1) and insert self-tapping screws (4). The number of holes (5) and the number of self-tapping screws (4) are determined according to the following steps: Step S11: Determine the uniformly distributed load design value of the two-way slab according to the floor design working conditions; Step S12: Determine the bending moment M of the long span and short span of the two-way slab according to the two-way slab design manual. l and M s ; Step S13: Determine the bending stiffness EI of the long span and short span of the two-way plate respectively l and EI s Step S14: According to the sliding stiffness and shear bearing capacity of a single hole (5) and the sliding stiffness and shear bearing capacity of a single self-tapping screw (4), iteratively determine the number of holes (5) and the number of self-tapping screws (4) in the long span and short span directions of the two-way plate; S2, fixing the two-way steel bars (3) on the upper surface of the orthogonal laminated wood or bamboo board (1) through the fixing device; S3, pouring the concrete (2) on the upper surface of the orthogonal laminated wood or bamboo board (1) to fill the holes (5) and completely cover the steel bars (3) and the self-tapping screws (4); wherein step S14 is specifically as follows: S14a, the shear bearing capacity of a single self-tapping screw (4) in the long span direction and the short span direction of the orthogonal laminated wood or bamboo board (1) is In formula 6, δ is the ratio of the compressive strength of the concrete (2) to the pin bearing compressive strength of the self-tapping screw (4), f h,β is the pin bearing compressive strength of the self-tapping screw (4), M y is the bending strength of the self-tapping screw (4), d is the diameter of the self-tapping screw (4), is the angle between the self-tapping screw (4) and the long-span direction; S14b, the shear bearing capacity of a single hole (5) in the long span direction and the short span direction of the orthogonal laminated wood or bamboo board (1) is In formula 7, fcv is the shear strength of the concrete (2), and dc is the diameter of the hole (5); S14c, the shear bearing capacity of the long span direction and the short span direction of the orthogonal laminated wood or bamboo board (1) is In formula 8, n ls and n ss is the number of self-tapping screws (4) in the long-span direction and the short-span direction of the orthogonal laminated wood or bamboo board (1). S14d, the shear of the long span direction and the short span direction of the orthogonal laminated wood or bamboo board (1) is In formula 9, M l and M s is the bending moment of the long span and the short span of the bidirectional plate, μ1 and μ s is the bending moment-shear force ratio of the long span and the short span of the orthogonal glued wood or bamboo plate (1); L1 and L s is the span of the long span and the short span of the orthogonal glued wood or bamboo plate (1). S14e, firstly, assuming that the number of holes (5) in the long span direction is 1, the number of self-tapping screws (4) is 2, the angle between the self-tapping screws (4) and the bamboo grain / wood grain direction and the long span direction is 45°, and the diameter of the hole (5) is 5-15 times the diameter of the self-tapping screw (4), the sliding stiffness in the long span direction is calculated, then the interlayer shear and the shear bearing capacity in the long span direction are calculated, if the shear bearing capacity is greater than the interlayer shear, the self-tapping screws (4) and the holes (5) in this direction are arranged according to the assumption; if the shear bearing capacity is less than the interlayer shear, the number of holes (5) is increased under the condition of ensuring the spacing of the holes (5), when the number of holes (5) on one side exceeds one row, the holes (5) are arranged in one row, and the excess holes (5) are replaced by self-tapping screws (4); The number of holes (5) and self-tapping screws (4) in the short span direction is obtained by the same method.

2. The production method according to claim 1, wherein A row of circular holes (5) is arranged on the upper surface of the orthogonal laminated wood or bamboo board (1) along the long span and short span directions, and each row of holes (5) is arranged equidistantly near the edge of the orthogonal laminated wood or bamboo board (1); The depth of the hole (5) is the thickness of the single-layer board of the orthogonal laminated wood or bamboo board (1), and the center distance of the hole (5) is not less than 2 times the diameter of the hole (5).

3. The production method according to claim 1, wherein In the thickness direction of the board, the angle between the self-tapping screw (4) and the orthogonal laminated wood or bamboo board (1) is 45°-90°. The drilling direction of the self-tapping screws (4) on both sides of the long-span direction of the orthogonal laminated wood or bamboo board (1) is arranged in the plastic strand direction, and a plurality of rows of self-tapping screws (4) with the drilling direction arranged in the short-span direction are arranged in the middle of the span.

4. The production method according to claim 1, wherein The two arrangement directions of the bidirectional steel bars (3) are consistent with the long-span and short-span directions of the orthogonal laminated wood or bamboo board (1).

5. The production method according to claim 1, wherein The calculation process of step S13 is as follows: S13a, the bending stiffness expression of the long-span and short-span of the bidirectional board is: In formula 1: E1 and E2 are the elastic modulus of concrete (2) and orthogonal glulam or bamboo panel (1) respectively; I l1 and I s1 are the moment of inertia of concrete long span direction and short span direction respectively; r l1 and r s1 are the connection coefficient of orthogonal glulam or bamboo panel (1) long span direction and short span direction respectively; A l1 and A s1 are the equivalent cross-sectional area of orthogonal glulam or bamboo panel (1) long span direction and short span direction respectively; a l1 and a s1 are the distance between the centroid of orthogonal glulam or bamboo panel (1) long span direction and short span direction and the centroid of the composite section respectively; S13b, the distance expression between the centroid of the long-span and short-span directions of the orthogonal laminated wood or bamboo board (1) and the centroid of the combined section is: In formula 2, h1 is the thickness of the concrete (2), h l2 and h s2 are the equivalent heights of the long-span direction and the short-span direction of the orthogonal glulam or bamboo board (1), respectively. S13c, the expression of the connection coefficient is: In formula 3, s l1 and s s1 are the spacing of self-tapping screws (4) in the long-span direction and the short-span direction of the orthogonal glued laminated wood or bamboo board (1); K l1 and K l2 are the slip stiffness in the long-span direction and the short-span direction of the orthogonal glued laminated wood or bamboo board (1); L1 and L2 are the span in the long-span direction and the short-span direction of the orthogonal glued laminated wood or bamboo board (1); S13d, the slip stiffness expression of the long-span and short-span directions of the orthogonal laminated wood or bamboo board (1) is: In formula 4, n ls and n ss are the number of self-tapping screws (4) in the long-span direction and the short-span direction of the orthogonal glued wood or bamboo board (1); K ls and K ss are the slip stiffness of a single self-tapping screw (4) in the long-span direction and the short-span direction of the orthogonal glued wood or bamboo board (1); n ls and n ss are the number of holes (5) in the long-span direction and the short-span direction of the orthogonal glued wood or bamboo board (1); K lc and K sc are the slip stiffness of a single hole (5) in the long-span direction and the short-span direction of the orthogonal glued wood or bamboo board (1); The slip stiffness expression of a single self-tapping screw (4) in the long-span and short-span directions of the orthogonal laminated wood or bamboo board (1) is: In formula 5, p is the density of bamboo or wood in the cross-laminated bamboo or wood board (1), d is the diameter of the self-tapping screw (4), β is the angle between the self-tapping screw (4) and the longitudinal direction of the bamboo or wood, is the angle between the self-tapping screw (4) and the long-span direction; The slip stiffness of a single hole (5) is taken as n times the slip stiffness of a single self-tapping screw (4) in the direction.

6. The production method according to claim 1, wherein The number and geometric size of the self-tapping screws arranged in the plastic strand direction are referred to the arrangement of the self-tapping screws in the short-span direction.

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