A directional metal fiber reinforced butterfly-shaped concrete slab and a preparation method thereof

Abstract

The present application relates to a kind of directional metal fiber reinforced butterfly-shaped concrete slab and preparation method, including concrete slab main body, the concrete slab main body two sides are recessed with arc-shaped groove towards inside to make concrete slab main body present butterfly-shaped, two arc-shaped groove middle part extends along its tangent direction, and it is divided into the parallelogram-like tensile-compressive mixed stress zone in the middle of concrete slab main body and two pairs of diagonal main pressure stress zone, and the tensile-compressive mixed stress zone and main pressure stress zone are inlaid with the concrete pouring forming of metal fiber;The metal fiber in the tensile-compressive mixed stress zone is uniformly distributed in the direction of directional magnetic field, and the metal fiber in the main pressure stress zone is randomly distributed, which has the advantages of reasonable structure design, industrial production, convenient construction, reducing structural weight, improving structural size accuracy and quality, and reducing the amount of steel reinforcement.

Description

Technical Field

[0001] The invention relates to the field of concrete slab presetting, and in particular to a butterfly-shaped concrete slab reinforced with directional metal fibers and a preparation method thereof. Background Art

[0002] Traditional concrete box structures offer excellent stability and resistance to bending and torsional forces, and are commonly used for main beams in beam bridges and arch ribs in arch bridges. However, as bridge spans increase, their increasing deadweight, the susceptibility of concrete webs to cracking, and the difficulty of construction are the main factors restricting their application. While the steel web (rod)-concrete composite box structure improves upon the shortcomings of traditional concrete box structures, it uses a large amount of steel, resulting in high construction and maintenance costs, poor durability, and complex joint connections. Therefore, prestressed fiber-reinforced concrete butterfly slabs have been developed to replace traditional concrete or steel webs (rods), reducing their deadweight while improving their durability. The load-bearing behavior of prestressed fiber-reinforced concrete butterfly slabs is similar to that of a double Warren truss, with distinct zones of mixed tension and compression and zones of primary compression. Summary of the Invention

[0003] In view of the shortcomings of the existing technology, the technical problem to be solved by the present invention is to provide a butterfly-shaped concrete slab reinforced with directional metal fibers and a preparation method. By directional distribution of metal fibers in the tensile and compressive stress areas of the butterfly slab, the contribution of metal fibers to the tensile properties of concrete is fully utilized, eliminating the need for prestressed steel strands or ordinary steel bars in the butterfly slab. The butterfly-shaped concrete slab reinforced with directional metal fibers can serve as the web of a box beam or box arch rib. While retaining the advantages of the original structure, the butterfly-shaped concrete slab reinforced with directional metal fibers maximizes the metal fibers' improvement in the tensile properties of concrete, reduces the amount of steel bars used, and further reduces construction costs.

[0004] In order to solve the above technical problems, the technical solution of the present invention is: a butterfly-shaped concrete slab reinforced with directional metal fibers, comprising a concrete slab main body, wherein arc-shaped grooves are concave inward on both sides of the concrete slab main body to make the concrete slab main body butterfly-shaped, and the middle parts of the two arc-shaped grooves extend along their tangent directions to divide the concrete slab main body into a parallelogram-shaped mixed tension and compression stress zone and two diagonal trapezoidal main compression stress zones, both of which are cast and formed by concrete mixed with metal fibers; the metal fibers in the mixed tension and compression stress zone are distributed in a consistent direction after applying a directional magnetic field, and the metal fibers in the main compression stress zone are distributed in a random direction.

[0005] Furthermore, the two main compressive stress zones are centrally and symmetrically arranged at diagonal positions on both sides of the concrete slab body.

[0006] Furthermore, the orientation of the metal fibers in the tension-compression mixed stress zone is consistent with the length extension direction of the tension-compression mixed stress zone.

[0007] Furthermore, the joint surfaces of the tension-compression mixed stress zone and the main compression stress zones on both sides thereof are corrugated and cast together.

[0008] Furthermore, the mixed tension-compression stress zone and the main compression stress zone are both cast and formed by high-performance concrete or ultra-high-performance concrete.

[0009] Furthermore, the metal fiber is steel fiber or stainless steel fiber.

[0010] A method for preparing a butterfly-shaped concrete slab reinforced with oriented metal fibers comprises a butterfly-shaped concrete slab plastic mold for casting the concrete slab body, a corrugated plastic partition for separating a mixed tension-compression stress zone from a main compression stress zone, and an electromagnetic controller and an electromagnetic coil for magnetization. The method is carried out in the following steps:

[0011] (1) Place the butterfly-shaped concrete slab plastic mold horizontally and install a corrugated plastic partition inside the butterfly-shaped concrete slab plastic mold to separate the tensile and compressive mixed stress area of ​​the concrete slab body from the main compressive stress area;

[0012] (2) Magnetizing the metal fiber;

[0013] (3) Using magnetized metal fibers, cementitious materials, quartz sand, quartz powder, water reducer and water to prepare metal fiber reinforced high performance concrete or ultra high performance concrete;

[0014] (4) Pour the mixed high-performance concrete or ultra-high-performance concrete grouting material into the tensile and compressive mixed stress area of ​​the butterfly-shaped concrete slab plastic mold. After the grouting is in place, place the plastic mold on a vibration table and vibrate it to expel the bubbles inside the concrete;

[0015] (5) Place the concrete slab in a ring-shaped electromagnetic coil and energize it to apply a directional magnetic field to the metal fibers in the concrete slab to complete the directional arrangement of the metal fibers. Then, cut off the current and remove the concrete slab body from the ring-shaped electromagnetic coil.

[0016] (6) Pour the mixed high-performance concrete or ultra-high-performance concrete grouting material into the main compressive stress area of ​​the butterfly concrete slab. When the concrete height of the main compressive stress area is equal to the concrete height of the tension-compression mixed stress area, slowly remove the corrugated plastic partition and lightly vibrate the plastic mold shell to make the concrete at the junction of the tension-compression area bonded into a whole;

[0017] (7) After the main body of the concrete slab is cured indoors for 24 hours, the formwork is removed and the main body of the concrete slab is moved into a standard curing room for curing for 28 days or steam curing for 2 to 3 days. The preparation is then complete.

[0018] Furthermore, both ends of the corrugated plastic partition are fastened to the butterfly-shaped concrete slab plastic mold through corrugated plastic partition pins, and both ends of the corrugated plastic partition pass through the butterfly-shaped concrete slab plastic mold and are clamped and limited by fastening plates.

[0019] Compared with existing technologies, the present invention has the following advantages: By utilizing factory prefabrication and oriented metal fiber technology, the high-performance concrete or ultra-high-performance concrete butterfly slab incorporating metal fibers can fully utilize the tensile properties of its mixed tension-compression stress zone and the compressive properties of its primary compression stress zone, while maintaining the same metal fiber content. This eliminates or reduces the need for steel bars or prestressed steel strands within the butterfly slab, saving labor and material costs and reducing carbon emissions. The present invention also features a simple structure, rational design, convenient construction, and improved overall economic benefits.

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of the structure of an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of the preparation of an embodiment of the present invention;

[0023] Figure 3 Schematic diagram of the connection between the butterfly-shaped concrete slab plastic mold and the corrugated plastic partition in an embodiment of the present invention;

[0024] Figure 4 Schematic diagram of the structure of the corrugated plastic partition in an embodiment of the present invention.

[0025] In the figure: 1-concrete slab body, 2-arc groove, 3-butterfly-shaped concrete slab plastic mold, 4-tension-compression mixed stress area, 5-main compression stress area, 6-metal fiber, 7-corrugated plastic partition, 8-electromagnetic controller, 9-electromagnetic coil, 10-corrugated plastic partition pin, 11-fastening plate. DETAILED DESCRIPTION

[0026] In order to make the above features and advantages of the present invention more clearly understood, embodiments are given below with reference to the accompanying drawings for detailed description.

[0027] like Figures 1 to 4As shown, a butterfly-shaped concrete slab reinforced with directional metal fibers comprises a concrete slab body 1, wherein arcuate grooves 2 are concave inwardly on both sides of the concrete slab body to give the concrete slab body a butterfly shape, wherein the middle portions of the two arcuate grooves extend along their tangent directions to divide the concrete slab body into a parallelogram-like tension-compression mixed stress zone 4 and two diagonal trapezoidal main compression stress zones 5, wherein both the tension-compression mixed stress zone and the main compression stress zone are cast and formed by concrete mixed with metal fibers 6; the metal fibers in the tension-compression mixed stress zone are distributed in a consistent direction under the application of a directional magnetic field, while the metal fibers in the main compression stress zone are distributed in a random direction.

[0028] In the embodiment of the present invention, the two main compressive stress zones are centrally symmetrically arranged at diagonal positions on both sides of the concrete slab body.

[0029] In an embodiment of the present invention, the orientation of the metal fibers in the tension-compression mixed stress zone is consistent with the length extension direction of the tension-compression mixed stress zone.

[0030] In an embodiment of the present invention, the joint surfaces of the tension-compression mixed stress zone and the main compression stress zones on both sides thereof are corrugated and cast together.

[0031] In an embodiment of the present invention, the tension-compression mixed stress zone and the main compression stress zone are both cast and formed by high-performance concrete or ultra-high-performance concrete.

[0032] In an embodiment of the present invention, the metal fiber is steel fiber or stainless steel fiber.

[0033] A method for preparing a butterfly-shaped concrete slab reinforced with oriented metal fibers first requires preparing a butterfly-shaped concrete slab plastic mold 3 and a corrugated plastic partition 7 for separating the mixed tension-compression stress zone from the main compression stress zone, as well as an electromagnetic controller 8 and an electromagnetic coil 9 for magnetization:

[0034] (1) Place the butterfly-shaped concrete slab plastic mold horizontally and install a corrugated plastic partition inside the butterfly-shaped concrete slab plastic mold to separate the tensile and compressive mixed stress area of ​​the concrete slab body from the main compressive stress area;

[0035] (2) Magnetizing the metal fiber;

[0036] (3) Using magnetized metal fibers, cementitious materials, quartz sand, quartz powder, water reducer and water to prepare metal fiber reinforced high performance concrete or ultra high performance concrete;

[0037] (4) Pour the mixed high-performance concrete or ultra-high-performance concrete grouting material into the tensile and compressive mixed stress area of ​​the butterfly-shaped concrete slab plastic mold. After the grouting is in place, place the plastic mold on a vibration table and vibrate it to expel the bubbles inside the concrete;

[0038] (5) Place the concrete slab in the annular electromagnetic coil and energize it to apply a directional magnetic field to the metal fibers in the concrete slab to complete the directional arrangement of the metal fibers. Then, cut off the current and remove the concrete slab from the annular electromagnetic coil.

[0039] (6) Pour the mixed high-performance concrete or ultra-high-performance concrete grouting material into the main compressive stress area of ​​the butterfly concrete slab. When the concrete height of the main compressive stress area is equal to that of the tensile-compression mixed stress area, slowly remove the corrugated plastic partition and lightly vibrate the plastic mold shell to make the concrete at the junction of the tensile and compressive areas bonded into a whole. The vibration process should avoid disturbing the oriented metal fibers.

[0040] (7) The concrete slab body is cured indoors with formwork for 24 hours and then removed from the formwork. The concrete slab body is then moved into a standard curing room and cured for 28 days or steam cured for 2 to 3 days. The directional metal fiber reinforced butterfly concrete slab is then prepared.

[0041] In the embodiment of the present invention, both ends of the corrugated plastic partition are fastened to the butterfly concrete slab plastic mold via the corrugated plastic partition pins 10 , and both ends of the corrugated plastic partition pass through the butterfly concrete slab plastic mold and are clamped and limited by the fastening plates 11 .

[0042] The present invention is not limited to the above-described preferred embodiment. Based on the teachings of this invention, anyone can devise various other forms of butterfly-shaped concrete slabs reinforced with oriented metal fibers and their preparation methods. All equivalent variations and modifications made within the scope of the present invention are intended to fall within the scope of this invention.

Claims

1. A method for preparing a butterfly-shaped concrete slab reinforced with oriented metal fibers, characterized by: The concrete slab comprises a main body, wherein two sides of the main body of the concrete slab are concave with arcuate grooves facing inwards, so that the main body of the concrete slab is butterfly-shaped. The middle parts of the two arcuate grooves extend along their tangent directions to separate a parallelogram-shaped tension-compression mixed stress zone in the main body of the concrete slab and two diagonal trapezoidal main stress zones. The tension-compression mixed stress zone and the main stress zone are both cast and formed by concrete mixed with metal fibers. The metal fibers in the tension-compression mixed stress zone are uniformly oriented and distributed under the application of a directional magnetic field, while the metal fibers in the main stress zone are randomly distributed. The method includes a butterfly-shaped concrete slab plastic mold for casting the concrete slab body, a corrugated plastic partition for separating the tension-compression mixed stress zone and the main compression stress zone, and an electromagnetic controller and an electromagnetic coil for magnetization, and is carried out in the following steps: (1) Place the butterfly-shaped concrete slab plastic mold horizontally and install a corrugated plastic partition inside the butterfly-shaped concrete slab plastic mold to separate the tensile and compressive mixed stress area of ​​the concrete slab body from the main compressive stress area; (2) Magnetizing the metal fiber; (3) Using materials to prepare metal fiber reinforced high performance concrete or ultra-high performance concrete; (4) Pour the mixed high-performance concrete or ultra-high-performance concrete grouting material into the tensile and compressive mixed stress area of ​​the butterfly-shaped concrete slab plastic mold. After the grouting is in place, place the plastic mold on a vibration table and vibrate it to expel the bubbles inside the concrete; (5) Place the concrete slab in a ring-shaped electromagnetic coil and energize it to apply a directional magnetic field to the metal fibers in the concrete slab to complete the directional arrangement of the metal fibers. Then, cut off the current and remove the concrete slab body from the ring-shaped electromagnetic coil. (6) Pour the mixed high-performance concrete or ultra-high-performance concrete grouting material into the main compressive stress area of ​​the butterfly concrete slab. When the concrete height of the main compressive stress area is equal to the concrete height of the tension-compression mixed stress area, slowly remove the corrugated plastic partition and lightly vibrate the plastic mold shell to make the concrete at the junction of the tension-compression area bonded into a whole; (7) After the main body of the concrete slab is cured indoors for 24 hours, the formwork is removed and the main body of the concrete slab is moved into a standard curing room for curing for 28 days or steam curing for 2 to 3 days. The preparation is then complete.

2. The method for preparing a butterfly-shaped concrete slab reinforced with oriented metal fibers according to claim 1, characterized in that: The orientation of the metal fibers in the tension-compression mixed stress zone is consistent with the length extension direction of the tension-compression mixed stress zone.

3. The method for preparing a butterfly-shaped concrete slab reinforced with oriented metal fibers according to claim 1, characterized in that: The metal fibers are steel fibers.

4. The method for preparing a butterfly-shaped concrete slab reinforced with oriented metal fibers according to claim 1, characterized in that: Both ends of the corrugated plastic partition are fastened with the butterfly-shaped concrete slab plastic mold through corrugated plastic partition pins, and both ends of the corrugated plastic partition pass through the butterfly-shaped concrete slab plastic mold and are clamped and limited by fastening plates.

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