A TRC permanent formwork steel-concrete composite beam and its preparation method

Abstract

The present application discloses a new type of TRC permanent formwork steel-concrete composite beam and its preparation method, which is composed of high-performance fine aggregate concrete, a fabric mesh fixed by a stainless steel wire mesh lining, a box-shaped steel beam, a steel bar framework, cast-in-place concrete, a side form cavity, an upper form cavity, raised rib strips, an outer plate, an inner plate, and an internal transverse plate; the TRC formwork serves as a permanent formwork, eliminating the need for additional formwork, simplifying the construction process of formwork erection and removal for cast-in-place reinforced concrete structures, improving construction efficiency, reducing project costs, and shortening construction time; the lower part of the steel-concrete composite beam is a hollow box-shaped steel beam, saving materials, making the beam lighter in weight, and making full use of the tensile properties of steel and the compressive properties of concrete; the box-shaped steel beam is protected by a dense TRC formwork on the outside, and its chloride ion penetration resistance and water penetration resistance are far superior to those of ordinary concrete, effectively preventing the corrosion of the steel beam, and at the same time enhancing the fire resistance of the steel-concrete composite beam and improving the durability of the structure.

Description

Technical Field

[0001] This application relates to the technical field of composite beams, and particularly relates to a TRC permanent formwork steel-concrete composite beam and a preparation method thereof. Background Art

[0002] As an important tool in the construction of cast-in-situ concrete structures, the technical performance of formwork directly affects the quality, cost of construction projects, and the economic benefits of enterprises. According to statistics, in the construction of cast-in-situ concrete structures, for every 1 m 2 the formwork consumption for concrete projects is as high as 4 - 5 m 2 , and its project cost accounts for 30% - 35% of the cost of cast-in-situ concrete structures, the labor consumption accounts for 40% - 50%, and about 50% of the construction period. The formwork project occupies a relatively large cost and construction period, and is an important factor affecting the construction progress, cost, and construction quality of the project.

[0003] The steel-concrete composite beam is a new type of beam developed on the basis of steel structures and concrete structures. Usually, its rib part uses a steel beam, and the wing plate uses a concrete slab, and the two are connected into a whole by shear connectors or perforated steel plates. The two materials are combined in the form of a composite beam, which can avoid their respective disadvantages, give full play to the advantages of the two materials, and form a structural form with high strength, large stiffness, and good ductility. Compared with concrete beams, the steel-concrete composite beam has the advantages of light weight, large bearing capacity, and strong spanning ability; compared with steel plate beams, the steel-concrete composite beam saves about 20% - 40% of steel and can reduce the cost. However, the main defect of the common profiled steel exposed steel-concrete composite beam is that due to the exposure of steel, it is prone to corrosion and its fire resistance is not as good as that of reinforced concrete.

[0004] Textile Reinforced Concrete (TRC for short) is a new composite material formed by the combination of high-performance fine aggregate concrete and multi-axial alkali-resistant fiber meshes (such as carbon fiber, alkali-resistant glass fiber, basalt fiber, etc.). It has the advantages of good bearing capacity, crack control ability, thin wall, light weight, high strength, corrosion resistance, and strong plasticity, and is commonly used in the fields of light precast components and structural reinforcement. Summary of the Invention

[0005] Technical problems to be solved: In order to reduce the engineering quantity of formwork, improve the construction efficiency, overcome the problems of easy corrosion and poor fire resistance of steel-concrete composite beams, and improve the durability of the structure, the present application provides a TRC permanent formwork steel-concrete composite beam and its preparation method. The TRC thin plate is used as a U-shaped permanent formwork, and a box-shaped steel beam is arranged in the lower half of the U-shaped cavity of the U-shaped permanent formwork to form a U-shaped TRC combined permanent formwork. The height of the box-shaped steel beam is half of the height of the composite beam. In the compression zone of the upper half of the U-shaped cavity of the U-shaped TRC combined permanent formwork, a steel bar cage is placed, and concrete is poured to form a TRC permanent formwork steel-concrete composite beam.

[0006] Technical solution: A TRC permanent formwork steel-concrete composite beam, which is composed of high-performance fine aggregate concrete, a fabric mesh fixed by a stainless steel plate mesh, a box-shaped steel beam, a steel bar cage, cast-in-place concrete, a side form cavity, an upper form cavity, raised ribs, an outer plate, an inner plate, and an internal transverse plate. There are two inner plates and two outer plates. The inner plates and the outer plates are arranged in parallel. The two inner plates are arranged between the two outer plates. The bottoms of the two inner plates are connected to the bottoms of the two outer plates, and the tops of the two inner plates are connected by an internal transverse plate. A side form cavity is formed between the inner plate and the outer plate, and an upper form cavity is formed between the internal transverse plate and the outer plate. Raised ribs are arranged on the side of the form cavity of the inner plate. The box-shaped steel beam is arranged on the internal transverse plate. The fabric mesh fixed by the stainless steel plate mesh is arranged in the side form cavity and the upper form cavity. The high-performance fine aggregate concrete is poured into the side form cavity and the upper form cavity except for the box-shaped steel beam. The steel bar cage is placed on the box-shaped steel beam, and the cast-in-place concrete is arranged in the U-shaped cavity formed by the high-performance fine aggregate concrete and the box-shaped steel beam.

[0007] As a preferred technical solution of the present application, the height of the inner plate of the side form cavity is half of the designed beam height.

[0008] As a preferred technical solution of the present application, the height of the box-shaped steel beam is half of the designed beam height.

[0009] As a preferred technical solution of the present application, each side of the box-shaped steel beam extends 1-2 cm beyond the inner plate.

[0010] As a preferred technical solution of the present application, the outer surface of the box-shaped steel beam is provided with patterned protrusions.

[0011] As a preferred technical solution of the present application, the fabric mesh fixed by the stainless steel plate mesh is composed of a U-shaped stainless steel plate mesh and a fabric mesh.

[0012] . A preparation method of a TRC permanent formwork steel-concrete composite beam includes the following steps:

[0013] The first step is to fabricate the U-shaped TRC composite permanent formwork: According to the beam design, fabricate a concave formwork for pouring the U-shaped TRC composite permanent formwork; invert the concave formwork to form an inverted concave shape; the mold cavity of the inverted concave formwork consists of two wing side mold cavities and an upper mold cavity. The two wing side mold cavities correspond to the two side TRC formworks of the U-shaped TRC composite permanent formwork, and the upper mold cavity corresponds to the bottom TRC cross formwork and the box girder of the U-shaped TRC composite permanent formwork. Each side mold cavity is composed of an inner plate and an outer plate, and the upper mold cavity is composed of an inner cross plate and the outer plate of the side mold cavity; the height of the inner plate of the side mold cavity is half of the designed beam height, and raised ribs are provided on the side of the mold cavity of the inner plate to form inner grooves on both sides of the U-shaped TRC composite permanent formwork;

[0014] The second step: Place the box girder in the center on the inner cross plate, and clamp the box girder and the inner cross plate at both ends of the girder with a carpenter's clamp; the height of the box girder is half of the designed beam height, and each side of the girder extends 1-2 cm beyond the inner plate; the box girder is made of patterned steel plate by rolling or welding, and patterned protrusions are arranged on the outer surface of the box girder;

[0015] The third step: Cut the multi-axial alkali-resistant fabric mesh and stainless steel plate mesh according to the design dimensions of the beam, roll the cut stainless steel plate mesh into a U-shaped mesh liner, and then tie the fabric mesh to the surface of the stainless steel plate mesh liner with thin iron wires to firmly fix the fabric mesh and the stainless steel plate mesh liner together; when tying the fabric mesh, straighten the fabric mesh at the same time, and keep it in a straightened state during the tying process to form a fabric mesh fixed by the stainless steel plate mesh liner;

[0016] The fourth step: Place the fabric mesh fixed by the stainless steel plate mesh liner into the two wing side mold cavities and the upper mold cavity of the inverted concave formwork;

[0017] The fifth step: Pour high-performance fine aggregate concrete from the upper opening of the inverted concave formwork and vibrate it;

[0018] The sixth step: After curing, remove the inverted concave formwork to form a U-shaped TRC composite permanent formwork; the common mix ratio of the high-performance fine aggregate concrete in the TRC is: cement (C): sand (S): water (W): external water reducer (JM-PCA(Ⅰ)) = 1:1.4: 0.32:0.015; the cement is 52.5 ordinary Portland cement; the test sand is medium sand with a fineness modulus of 2.6 in Zone II and an apparent density of 1.2 g / cm3; the external water reducer is JM-PCA(Ⅰ) type superplasticizer;

[0019] The seventh step: Place the tied steel bar cage into the U-shaped cavity of the U-shaped TRC composite permanent formwork. The steel bar cage is placed on the box girder and is equidistant from the two side TRC formworks;

[0020] Step 8, cast in-situ concrete into the U-shaped cavity: Fill the U-shaped cavity of the entire TRC permanent formwork with the mixed in-situ concrete, then level the concrete surface, and cure the concrete to the specified age to complete the preparation of the steel-concrete composite beam with the TRC permanent formwork.

[0021] Beneficial effects: Compared with the prior art, the steel-concrete composite beam with the TRC permanent formwork and its preparation method described in this application have the following technical effects:

[0022] 1. Due to the advantages of TRC such as light weight, high strength, crack resistance, and corrosion resistance, TRC can be made very thin, especially suitable as a permanent formwork.

[0023] 2. On the one hand, the self-weight of TRC is light, which is convenient for construction; on the other hand, TRC can bear the external load during construction.

[0024] 3. Compared with fixing by impregnating and hardening fabric meshes, using stainless steel plate meshes for fixing is simpler and easier, and can improve the stiffness and punching shear resistance of the TRC formwork, avoiding excessive deformation or damage during transportation and construction.

[0025] 4. It forms a steel-concrete composite beam form where the tension zone is mainly the steel beam and the compression zone is the upper in-situ concrete.

[0026] 5. The lower TRC not only acts as a formwork but also can be part of the structure, bearing part of the tension in the tension zone and improving the bearing capacity of the composite beam.

[0027] 6. The pattern protrusions on the outer surface of the steel beam need to meet certain height requirements, so as to effectively increase the bonding and biting effect between the steel beam and the in-situ concrete and fine aggregate concrete. And there are grooves on the inner sides of the two side formworks of the TRC composite permanent formwork, making the in-situ concrete and fine aggregate concrete better bonded together.

[0028] 7. For this steel-concrete composite beam with the TRC permanent formwork, during the stage of casting the upper concrete in-situ, the TRC formwork serves as a permanent formwork and does not require additional formwork, simplifying the construction process of formwork erection and removal for in-situ reinforced concrete structures, improving construction efficiency, reducing project costs, and shortening construction time; the lower part of the steel-concrete composite beam is a hollow box-shaped steel beam, saving materials, making the beam lighter in weight, and being able to make full use of the tensile performance of steel and the compressive performance of concrete; the box-shaped steel beam is protected by a dense TRC formwork on the outside, and its chloride ion penetration resistance and water penetration resistance are much better than ordinary concrete, which can effectively prevent the corrosion of the steel beam, and at the same time can also enhance the fire resistance of the steel-concrete composite beam and improve the durability of the structure.

[0029] 8. The lower half of the U-shaped TRC composite permanent formwork is a hollow box-shaped steel beam, which can significantly reduce the weight of the beam and bear the tension in the tension zone of the beam. Description of the Drawings

[0030] Figure 1 It is a schematic diagram of a steel-concrete composite beam with a TRC permanent formwork.

[0031] Figure 2 It is a schematic diagram of a re-entrant formwork structure, where Figure 2 (a) Front view of the re-entrant formwork; Figure 2 (b) Top view of the re-entrant formwork.

[0032] Figure 3 It is a schematic diagram after a fabric mesh fixed by a stainless steel wire mesh lining and a box-shaped steel beam are placed in the re-entrant formwork.

[0033] Figure 4 It is a diagram of a box-shaped steel beam with patterned protrusions.

[0034] Figure 5 It is a schematic diagram of the structure of a U-shaped TRC composite permanent formwork, where Figure 5 (a) Front view of the U-shaped TRC composite permanent formwork; Figure 5 (b) Top view of the U-shaped TRC composite permanent formwork.

[0035] Description of the reference numerals in the drawings: 1 High-performance fine aggregate concrete; 2 Fabric mesh fixed by a stainless steel wire mesh lining; 3 Box-shaped steel beam; 4 Steel bar skeleton; 5 Cast-in-place concrete; 6 Side form cavity; 7 Upper form cavity; 8 Raised rib; 9 Outer plate; 10 Inner plate; 11 Inner transverse plate. Detailed Implementation Manner

[0036] Example 1: A steel-concrete composite beam with a TRC permanent formwork. The steel-concrete composite beam with a TRC permanent formwork is composed of high-performance fine aggregate concrete 1, a fabric mesh fixed by a stainless steel wire mesh lining 2, a box-shaped steel beam 3, a steel bar skeleton 4, cast-in-place concrete 5, a side form cavity 6, an upper form cavity 7, a raised rib 8, an outer plate 9, an inner plate 10, and an inner transverse plate 11. Two inner plates 10 and two outer plates 9 are provided. The inner plates 10 and the outer plates 9 are both arranged in parallel. The two inner plates 10 are arranged between the two outer plates 9. The bottoms of the two inner plates 10 are connected to the bottoms of the two outer plates 9. The tops of the two inner plates 10 are connected by an inner transverse plate 11. A side form cavity 6 is formed between the inner plate 10 and the outer plate 9. An upper form cavity 7 is formed between the inner transverse plate 11 and the outer plate 9. Raised ribs 8 are provided on the side of the form cavity of the inner plate 10. The box-shaped steel beam 3 is arranged on the inner transverse plate 11. The fabric mesh fixed by a stainless steel wire mesh lining 2 is arranged in the side form cavity 6 and the upper form cavity 7. The high-performance fine aggregate concrete 1 is poured into the side form cavity 6 and the upper form cavity 7 except for the box-shaped steel beam 3. The steel bar skeleton 4 is placed on the box-shaped steel beam 3. The cast-in-place concrete 5 is arranged in the U-shaped cavity formed by the high-performance fine aggregate concrete 1 and the box-shaped steel beam 3.

[0037] The preparation method of the TRC permanent formwork steel-concrete composite beam comprises the following steps:

[0038] First step, fabricate the U-shaped TRC composite permanent formwork: According to the beam design, fabricate the concave template for pouring the U-shaped TRC composite permanent formwork; invert the concave template to form an inverted concave shape; the cavity of the inverted concave template consists of two wing side cavities 6 and an upper cavity 7, the two wing side cavities 6 correspond to the two side TRC templates of the U-shaped TRC composite permanent formwork, and the upper cavity 7 corresponds to the bottom TRC cross template and the box girder 3 of the U-shaped TRC composite permanent formwork. Each side cavity 6 consists of an inner plate 10 and an outer plate 9, and the upper cavity 7 consists of an inner cross plate 11 and the outer plate 9 of the side cavity 6; the height of the inner plate 10 of the side cavity 6 is half of the designed beam height, and a raised rib 8 is provided on the cavity side of the inner plate 10 for forming the inner groove of the two side templates of the U-shaped TRC composite permanent formwork;

[0039] Second step: Place the box girder 3 at the center on the inner cross plate 11, and clamp the box girder and the inner cross plate at both ends of the girder with a carpenter's clamp; the height of the box girder 3 is half of the designed beam height, and each side of the girder extends 1-2 cm beyond the inner plate; the box girder 3 is made of patterned steel plate by rolling or welding, and patterned protrusions are arranged on the outer surface of the box girder 3;

[0040] Third step: Cut the multi-axial alkali-resistant fabric mesh and the stainless steel plate mesh according to the design dimensions of the beam, roll the cut stainless steel plate mesh into a U-shaped mesh liner, and then tie the fabric mesh to the surface of the stainless steel plate mesh liner with thin iron wires to firmly fix the fabric mesh and the stainless steel plate mesh liner together; when tying the fabric mesh, straighten the fabric mesh at the same time, and keep it in a straightened state during the tying process to form the fabric mesh 2 fixed by the stainless steel plate mesh liner;

[0041] Fourth step: Place the fabric mesh 2 fixed by the stainless steel plate mesh liner into the two wing side cavities 6 and the upper cavity 7 of the inverted concave template;

[0042] Fifth step: Pour the high-performance fine aggregate concrete 1 from the upper opening of the inverted concave template and vibrate it;

[0043] Sixth step: After curing, remove the inverted concave template to form the U-shaped TRC composite permanent formwork; the common mix ratio of the high-performance fine aggregate concrete in the TRC is: cement (C): sand (S): water (W): additional water reducer (JM-PCA (Ⅰ)) = 1:1.4:0.32:0.015; the cement is 52.5 ordinary Portland cement; the test sand is medium sand with a fineness modulus of 2.6 in Zone II and an apparent density of 1.2 g / cm 3 ; the additional water reducer is JM-PCA (Ⅰ) type superplasticizer;

[0044] Step 7: Place the tied steel bar framework 4 into the U-shaped cavity of the U-shaped TRC composite permanent formwork. The steel bar framework 4 is placed on the box-shaped steel beam 3 and is equidistant from the two sides of the TRC formwork.

[0045] Step 8, Cast in-situ concrete 5 into the U-shaped cavity: Fill the U-shaped cavity of the entire TRC permanent formwork with the mixed in-situ concrete 5, then level the surface of the concrete, and cure the concrete to the specified age to complete the preparation of the steel-concrete composite beam of the TRC permanent formwork.

[0046] The above are only the preferred embodiments of the present invention patent and are not intended to limit the present invention patent. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention patent shall be included within the protection scope of the present invention patent.

Claims

1. A preparation method of a TRC permanent formwork steel-concrete composite beam, characterized in that: The TRC permanent formwork steel-concrete composite beam is composed of high-performance fine aggregate concrete (1), fabric mesh fixed by stainless steel wire mesh lining (2), box girder (3), steel bar framework (4), cast-in-place concrete (5), side form cavity (6), upper form cavity (7), raised rib (8), outer side plate (9), inner side plate (10), and internal transverse plate (11). There are two inner side plates (10) and two outer side plates (9). The inner side plates (10) and the outer side plates (9) are arranged in parallel. The two inner side plates (10) are arranged between the two outer side plates (9). The bottoms of the two inner side plates (10) are connected to the bottoms of the two outer side plates (9). The tops of the two inner side plates (10) are connected by the internal transverse plate (11). A side form cavity (6) is formed between the inner side plate (10) and the outer side plate (9). An upper form cavity (7) is formed between the internal transverse plate (11) and the outer side plate (9). Raised ribs (8) are arranged on the form cavity side of the inner side plate (10). The box girder (3) is arranged on the internal transverse plate (11). The fabric mesh fixed by stainless steel wire mesh lining (2) is arranged in the side form cavity (6) and the upper form cavity (7). The high-performance fine aggregate concrete (1) is poured into the side form cavity (6) and the upper form cavity (7) except for the box girder (3). The steel bar framework (4) is placed on the box girder (3). The cast-in-place concrete (5) is arranged in the U-shaped cavity formed by the high-performance fine aggregate concrete (1) and the box girder (3). The preparation method of the TRC permanent formwork steel-concrete composite beam includes the following steps: The first step is to fabricate the U-shaped TRC composite permanent formwork: According to the beam design, fabricate a concave template for pouring the U-shaped TRC composite permanent formwork; invert the concave template to form an inverted concave shape; the form cavity of the inverted concave template consists of two wing side form cavities (6) and an upper form cavity (7). The two wing side form cavities (6) correspond to the two side TRC templates of the U-shaped TRC composite permanent formwork, and the upper form cavity (7) corresponds to the bottom TRC transverse template and the box girder (3) of the U-shaped TRC composite permanent formwork. Each side form cavity (6) is composed of an inner side plate (10) and an outer side plate (9). The upper form cavity (7) is composed of an internal transverse plate (11) and the outer side plate (9) of the side form cavity (6); the height of the inner side plate (10) of the side form cavity (6) is half of the designed beam height, and raised ribs (8) are arranged on the form cavity side of the inner side plate (10) to form inner grooves on both side templates of the U-shaped TRC composite permanent formwork; The second step: Place the box girder (3) in the center on the internal transverse plate (11), and clamp the box girder and the internal transverse plate at both ends of the girder with a carpenter's clamp; the height of the box girder (3) is half of the designed beam height, and each side of the girder extends 1-2 cm beyond the inner side plate (10); the box girder (3) is made of patterned steel plate by rolling or welding, and patterned protrusions are arranged on the outer surface of the box girder (3); Step 3: Cut the multi-axial alkali-resistant fabric mesh and stainless steel wire mesh according to the design dimensions of the beam. Roll the cut stainless steel wire mesh into a U-shaped mesh liner, and then tie the fabric mesh to the surface of the stainless steel mesh liner with thin iron wires, so that the fabric mesh and the stainless steel mesh liner are firmly fixed together; when tying the fabric mesh, straighten the fabric mesh at the same time, and keep it in a straightened state during the tying process to form a fabric mesh (2) fixed to the stainless steel mesh liner. Step 4: Place the fabric mesh (2) fixed to the stainless steel mesh liner into the two-wing side mold cavities (6) and the upper mold cavity (7) of the concave template. Step 5: Pour and vibrate the high-performance fine aggregate concrete (1) from the upper opening of the concave template. Step 6: After the curing is completed, remove the concave template to form a U-shaped permanent TRC composite template; the common mix ratio of the high-performance fine aggregate concrete in the TRC is: cement:sand:water:added water reducer = 1:1.4:0.32:0.015; the cement is 52.5 ordinary Portland cement; the test sand is medium sand in Zone II with a fineness modulus of 2.6 and an apparent density of 1.2 g / cm 3 ; the added water reducer is JM-PCA (I) type superplasticizer; Step 7: Place the tied steel reinforcement cage (4) into the U-shaped cavity of the U-shaped TRC composite permanent formwork. The steel reinforcement cage (4) is placed on the box-shaped steel beam (3) and is equidistant from the two sides of the TRC formwork. Step 8: Cast in-situ concrete (5) into the U-shaped cavity: Fill the U-shaped cavity of the entire TRC permanent formwork with the mixed in-situ concrete (5), then level the surface of the concrete, and cure the concrete to the specified age to complete the preparation of the steel-concrete composite beam of the TRC permanent formwork.

2. The preparation method of a TRC permanent formwork steel-concrete composite beam according to claim 1, characterized in that: Each side of the box-shaped steel beam (3) extends 1-2 cm beyond the inner plate (10).

3. The preparation method of a TRC permanent formwork steel-concrete composite beam according to claim 1, characterized in that: The fabric mesh (2) fixed to the stainless steel mesh liner is composed of a U-shaped stainless steel mesh and a fabric mesh.

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