Production method and mold for ribbed prestressed composite slab of self-compacting concrete

Abstract

The present disclosure provides a production method and a mold for a ribbed prestressed composite slab of self-compacting concrete, including a long-line table bottom mold, side molds, end molds and a top mold. Side molds are respectively connected to the long ends of the long-line table bottom mold. The top mold is arranged at the upper end of the long-line table bottom mold, and both ends of the top mold are respectively connected to the corresponding side molds. End molds are respectively connected to the short ends of the long-line table bottom mold, and the shape of the upper edge of the end mold matches the shape of the side edge of the top mold. Both ends of the end mold are respectively connected to the corresponding side molds to form a cavity with an accommodating space. A number of holes through which prestressed steel wires can pass are provided on the end mold, and leak-proof plugs are detachably connected to the holes. The structure of the present disclosure is simple, which can make the construction of prestressed concrete composite slabs faster and more convenient, and at the same time can reduce the labor intensity of workers and improve production efficiency.

Description

Technical Field

[0001] The present disclosure belongs to the technical field of construction engineering and relates to a production method and a mold for a self-compacting concrete ribbed prestressed composite slab. Background Art

[0002] The statements in this part merely provide background technical information related to the present disclosure and do not necessarily constitute prior art.

[0003] Concrete composite slabs act as formwork during the construction of housing buildings. After the composite layer concrete is poured, they form an integral part with the in-situ part and are part of the assembled monolithic structural system. They combine the advantages of good integrity and seismic performance of in-situ slabs and the advantages of saving formwork, easy realization of industrial production, fast construction speed, and improved component quality of precast slabs. In addition to the above advantages, precast ribbed prestressed concrete composite slabs also have the advantages of high bearing capacity and light self-weight, and are increasingly widely used in prefabricated buildings. However, as the inventor understands, for ordinary precast ribbed prestressed concrete composite slabs, the concrete bottom slab and ribs need to be poured and vibrated separately successively, which will bring (1) many construction procedures, long production time, and low labor efficiency; (2) the initial setting time of the concrete for the prestressed concrete composite slab cannot be too short, otherwise the concrete for the two constructions cannot be combined into an integral whole, it is difficult to use concrete with a short setting time and high early strength, reducing the production turnover efficiency; (3) there may be a risk of poor bonding between the bottom slab and rib concrete under special conditions, etc. Summary of the Invention

[0004] To solve the above problems, the present disclosure proposes a production method and a mold for a self-compacting concrete ribbed prestressed composite slab. The structure of the present disclosure is simple, which can make the construction of the prestressed concrete composite slab faster and more convenient, and at the same time can reduce the labor intensity of workers and improve production efficiency.

[0005] According to some embodiments, the present disclosure adopts the following technical solutions:

[0006] A mold for a self-compacting concrete ribbed prestressed composite slab includes a long-line table bottom mold, side molds, end molds, and a top mold. One side mold is respectively connected to the long ends of the long-line table bottom mold. A top mold is arranged above the long-line table bottom mold, and both ends of the top mold are respectively connected to the corresponding side molds;

[0007] One end mold is respectively connected to the short ends of the long-line table bottom mold, and the shape of the upper edge of the end mold matches the shape of the side edge of the top mold. Both ends of the end mold are respectively connected to the corresponding side molds to form a cavity with an accommodating space;

[0008] The end mold is provided with a plurality of holes through which prestressed steel wires can pass, and leak-proof plugs are detachably connected to the holes.

[0009] As a further limitation, the slurry leakage prevention plug is a hollow conical structure and can be clamped with the hole.

[0010] As a further limitation, the hollow part of the slurry leakage prevention plug is a cavity with a constant diameter, and the diameter is the same as the diameter of the prestressed steel wire of the applicable prestressed concrete composite slab.

[0011] As a further limitation, a plurality of grooves or / and protrusions, or patterns with a certain concave-convex depth are provided on the bottom surface of the top formwork.

[0012] As a possible embodiment, at least a part of the long-line table bottom formwork, end formwork and top formwork are detachably connected.

[0013] As a possible embodiment, the long-line table bottom formwork, side formwork, end formwork and top formwork are clamped.

[0014] As a possible embodiment, at the connection of the corresponding formworks where the long-line table bottom formwork, side formwork, end formwork and top formwork are connected, a clamping groove is provided on one formwork and a convex block is provided on the other formwork, and the convex block is adapted to the clamping groove.

[0015] A production method of a self-compacting concrete ribbed prestressed composite slab includes the following steps:

[0016] Erect and fix the concrete side formwork and end formwork;

[0017] Apply a release agent on the mold;

[0018] Pass the prestressed steel wire through the end formwork, and at the same time, sleeved a conical slurry leakage prevention plug on the prestressed steel wire outside the end formwork;

[0019] Pass the prestressed steel wire through the reserved holes of the tensioning platforms at both ends of the long-line table, sleeved conical prestressed wedge grips on the prestressed steel wire, and tension the prestressed steel wire;

[0020] Erect a tensile steel bar grid;

[0021] Erect and fix the concrete top formwork;

[0022] Continuously pour the prepared self-compacting concrete from the vacant part above the top formwork to the designed height;

[0023] After the concrete strength reaches a certain strength, remove the concrete top formwork, end formwork and side formwork;

[0024] After the concrete strength is nearly reaching the designed strength, relax the prestressed steel wire.

[0025] As a possible embodiment, the self-compacting concrete is prepared by stirring cement, slag powder, fly ash, sand, gravel, water and water reducing agent.

[0026] Furthermore, the weight ratio of each material in the self-compacting concrete is: cement: slag powder: fly ash: sand: gravel: water: water reducer = (0.4 - 0.6): (0.1 - 0.2): (0.25 - 0.45): (1.62 - 1.89): (1.49 - 1.75): (0.32 - 0.43): (0.003 - 0.05).

[0027] Furthermore, the fineness modulus of the sand is 2.6 - 2.9.

[0028] Furthermore, the water reducing rate of the water reducer is greater than 35%, and the slump loss within 1 hour should be less than 30 mm.

[0029] Furthermore, the maximum particle size of the gravel is 10 mm.

[0030] Furthermore, the cement should be of grade 42.5 or higher strength.

[0031] Furthermore, the mixing time of the self-compacting concrete in the mixer is 2.5 - 4 minutes.

[0032] Furthermore, when the self-compacting concrete is poured, the slump flow should be greater than 600 mm, and the difference between the slump flow and the J-ring expansion should not be greater than 50 mm.

[0033] Furthermore, the self-compacting concrete should not have bleeding.

[0034] Compared with the prior art, the beneficial effects of the present disclosure are as follows:

[0035] The present disclosure uses self-compacting concrete in the prestressed composite slab to achieve vibration-free construction, enabling the simultaneous pouring of the concrete in the rib and the bottom slab. This can reduce the construction procedures in the production of ribbed prestressed concrete composite slabs, improve production efficiency, and reduce the labor usage.

[0036] In the mold system of the present disclosure, a groove-shaped structure is provided in one of the templates among the mutually connected templates, and a part of the other template extends into the groove, which can prevent the slurry in the concrete from flowing out through the gap between the bottom mold and the side mold, reducing the loss of concrete materials.

[0037] The present disclosure provides tensile reinforcement bars in the ribs of the prestressed composite slab, which can improve the load-bearing capacity of the composite slab, increase the length of the composite slab or reduce the number of supports under the composite slab during construction, and reduce the thickness of the concrete in the composite layer.

[0038] The present disclosure provides a pattern with concavities and convexities under the top mold, which can enhance the bonding effect between the composite slab and the concrete in the composite layer. At the same time, the aesthetic or promotional effect can be increased through the design of the pattern. Description of the Drawings

[0039] The accompanying drawings forming a part of this disclosure are used to provide a further understanding of this disclosure. The schematic embodiments of this disclosure and their descriptions are used to explain this disclosure and do not constitute an improper limitation of this disclosure.

[0040] Figure 1 is a schematic diagram of the top mold structure of this disclosure;

[0041] Figure 2 is a schematic diagram of the side mold structure of this disclosure;

[0042] Figure 3 is a schematic diagram of the end mold structure of this disclosure;

[0043] Figure 4 is a schematic diagram of the relationship between the templates of this disclosure;

[0044] Figure 5 is a schematic diagram of the hollow leak-proof slurry plug of this disclosure. Detailed Description of the Invention

[0045] The present disclosure will be further described below in conjunction with the accompanying drawings and embodiments.

[0046] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present disclosure. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this disclosure belongs.

[0047] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to this disclosure. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0048] In this disclosure, terms such as "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "side", "bottom", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only relationship terms determined for the convenience of describing the structural relationship of each component or element of this disclosure and do not specifically refer to any component or element in this disclosure. It should not be construed as a limitation of this disclosure.

[0049] In the present disclosure, terms such as "fixed connection", "connected", "joined" should be understood in a broad sense, which may mean a fixed connection, an integral connection or a detachable connection; it may be directly connected or indirectly connected through an intermediate medium. For relevant scientific research or technical personnel in this field, the specific meanings of the above terms in the present disclosure can be determined according to specific circumstances, and should not be construed as a limitation to the present disclosure.

[0050] A mold / formwork suitable for non-vibrated ribbed prestressed concrete composite slabs is composed of a long-line table bottom formwork, side formworks, end formworks and top formworks. Side formworks are respectively arranged on the long sides of the long-line table bottom formwork, and end formworks are respectively arranged on the short sides. A top formwork is arranged at the upper ends of the side formworks and end formworks to form an integral mold.

[0051] As Figure 4 shown, when multiple formworks work together, a grooved structure is arranged in one of the mutually connected formworks (such as the side formwork), and a part of another formwork (such as the bottom formwork) extends into the groove. The purpose of this is to prevent concrete from flowing out between the side formwork and the bottom formwork after self-compacting concrete is poured, thus affecting the quality of the composite slab. Figure 4 In [reference] only shows the connection relationship between the molds, and the specific proportions of each formwork are not necessarily as shown in the figure.

[0052] As Figure 3 shown, the end formwork should be provided with holes through which prestressed steel wires can pass; in addition, the heights of the two ends of the end formwork should be adapted to the height of the side formwork.

[0053] The length of the end formwork is adapted to the width of the bottom formwork.

[0054] The upper edge shape of the end formwork is adapted to the top formwork. It has at least one groove part to coincide with the groove arranged on the top formwork.

[0055] As Figure 5 shown, the end formwork also includes a tapered hollow anti-leakage plug. The hollow part is a cavity with a constant diameter, and its diameter is the same as the diameter of the prestressed steel wire of the applicable prestressed concrete composite slab to ensure that the prestressed tendon can pass through. The hollow anti-leakage plug can be made of rubber material, and the external part of the solid part is a tapered structure. Due to the use of a taper and a relatively soft material, it can achieve close contact with the end formwork to prevent leakage of slurry.

[0056] As Figure 1As shown in the figure, the top formwork is composed of two L-shaped section formworks and one channel-shaped section formwork. The bottom surface of the horizontal part of the top formwork is engraved with a pattern with certain concavities and convexities. After removing the top formwork, the laminated slab will have certain concave and convex textures. After pouring the concrete of the upper laminated layer, the concave and convex textures will be able to improve the bonding strength between the concrete of the laminated slab and the concrete of the upper laminated layer, making the two into a whole. Through the design of the concave and convex pattern, information such as the enterprise name, logo, and publicity slogan can be presented on the laminated slab for the publicity of the enterprise and improving the enterprise image.

[0057] A manufacturing method for a self-compacting concrete ribbed prestressed laminated slab includes the following steps:

[0058] Erect and fix the concrete end formwork;

[0059] Apply a release agent on the formwork, and special attention should be paid to fully applying the release agent on the side formwork and the bottom formwork;

[0060] Pass the prestressed steel wire through the end formwork, and at the same time, put a conical anti-leakage plug on the prestressed steel wire outside the end formwork;

[0061] Pass the prestressed steel wire through the reserved holes of the tensioning platforms at both ends of the long-line table, put conical prestressed clamping pieces on the prestressed steel wire, and tension the prestressed steel wire;

[0062] Erect and fix the rib tensile diagonal steel bars or vertical steel bar meshes. Through mechanical analysis and load tests, it is found that the prestressed concrete laminated slab bears relatively large tensile stresses between the longitudinal quarter length of the rib and the end, and the tensile stresses are diagonal or vertical, and it is easy to cause tensile failure of the concrete in this part. Therefore, a tensile steel bar mesh is set in this part, and the steel bars bear the tensile stresses, which can improve the bearing capacity of the laminated slab.

[0063] To ensure the accurate position of the steel bars, the bottom steel bars of the rib tensile diagonal steel bars or vertical steel bar meshes should be placed with ring-shaped steel bar protective blocks at certain intervals;

[0064] Erect and fix the concrete top formwork;

[0065] Continuously pour the prepared self-compacting concrete from the vacant place above the top formwork to the designed height;

[0066] After the concrete reaches a certain strength (such as 3.5 MPa), remove the concrete top formwork, end formwork, and side formwork;

[0067] After the concrete strength reaches 75% - 85% of the design strength, the prestressed steel wires are released; releasing the prestressed steel bars when the strength is above 75% - 85% of the design strength is considered because after the prestressed steel bars are released, they will act as a kind of load on the concrete composite slab, and the concrete must have sufficient strength to resist the action of the prestress. At the same time, it is also because most of the shrinkage of the concrete has occurred after the concrete strength reaches 75% - 85% of the design strength. At this time, when the prestressed tendons are released again, the loss of prestress is smaller.

[0068] Transfer the prestressed concrete composite slab out of the production workshop.

[0069] The self-compacting concrete is prepared by mixing cement, slag powder, fly ash, sand, gravel, water, and water reducer. The weight ratio of each material is: cement: slag powder: fly ash: sand: gravel: water: water reducer = (0.4 - 0.6): (0.1 - 0.2): (0.25 - 0.45): (1.62 - 1.89): (1.49 - 1.75): (0.32 - 0.43): (0.003 - 0.05).

[0070] To ensure that the self-compacting concrete can achieve vibration-free, it is required to select raw materials. The main requirements are that the fineness modulus of the sand is 2.6 - 2.9; the water reduction rate of the water reducer is greater than 35%, and the slump loss within 1 hour should be less than 30 mm; the maximum particle size of the gravel is 10 mm. To ensure that the strength of the composite slab meets the requirements, the cement used should be of grade 42.5 or higher.

[0071] To ensure that the self-compacting concrete is evenly mixed, the mixing time of the self-compacting concrete in the mixer should be longer than that of ordinary concrete, and the time is 2.5 - 4 minutes.

[0072] To ensure that the self-compacting concrete can fill the entire mold, the fluidity of the self-compacting concrete during pouring should be good. The main control indexes are set as the slump flow should be greater than 600 mm, and the difference between the slump flow and the J-ring expansion should not be greater than 50 mm.

[0073] Of course, in different embodiments, the above parameters can be selected or changed according to specific requirements or situations, which are all simple replacements that can be thought of by those skilled in the art and should reasonably belong to the protection scope of the present disclosure.

[0074] In the production of prestressed concrete composite slabs, the homogeneity of the self-compacting concrete should be strictly controlled. There should be no bleeding in the self-compacting concrete because if there is bleeding on the concrete surface, it will cause poor bonding between the composite slab and the concrete of the composite layer.

[0075] The above are only the preferred embodiments of the present disclosure and are not intended to limit the present disclosure. For those skilled in the art, the present disclosure may have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present disclosure shall be included within the protection scope of the present disclosure.

[0076] Although the specific implementation manners of the present disclosure have been described above in conjunction with the accompanying drawings, it is not a limitation on the protection scope of the present disclosure. Those skilled in the art should understand that based on the technical solutions of the present disclosure, various modifications or deformations that can be made by those skilled in the art without creative efforts are still within the protection scope of the present disclosure.

Claims

1. A mold for self-compacting concrete ribbed prestressed composite slabs, characterized in that: It includes a long-line table bottom mold, side molds, end molds and a top mold. One side mold is respectively connected to the long ends of the long-line table bottom mold. The top mold is arranged at the upper end of the long-line table bottom mold, and both ends of the top mold are respectively connected to the corresponding side molds. The top mold has at least one concave part; the top mold is composed of two L-shaped cross-section templates and one trough-shaped cross-section template; One end mold is respectively connected to the short ends of the long-line table bottom mold, and the shape of the upper edge of the end mold matches the shape of the side edge of the top mold. Both ends of the end mold are respectively connected to the corresponding side molds to form a cavity with a containing space; The end mold has a number of holes through which the prestressed steel wires can pass, and a slurry leakage prevention plug is detachably connected to the holes; The slurry leakage prevention plug is a hollow conical structure and can be clamped with the holes; Or, the hollow part of the slurry leakage prevention plug is a cavity with a constant diameter, and the diameter is the same as the diameter of the prestressed steel wires of the applicable prestressed concrete composite slab.

2. The mold for self-compacting concrete ribbed prestressed composite slabs according to claim 1, characterized in that: The bottom surface of the top mold is provided with a number of grooves or / and protrusions, or a pattern with a certain concave-convex depth.

3. The mold for self-compacting concrete ribbed prestressed composite slabs according to claim 1, characterized in that: At least a part of the connection between the long-line table bottom mold, end molds and top mold is detachably connected; Or, the long-line table bottom mold, side molds, end molds and top mold are clamped.

4. The mold for self-compacting concrete ribbed prestressed composite slabs according to claim 1 or 3, characterized in that: Between the long-line table bottom mold, side molds, end molds and top mold, at the connection of the corresponding molds, one mold is provided with a card slot, and the other mold is provided with a convex block, and the convex block is adapted to the card slot.

5. A production method using the mold for self-compacting concrete ribbed prestressed composite slabs according to any one of claims 1-4, characterized in that: It includes the following steps: Erect and fix the concrete side molds and end molds; Apply a release agent on the mold; Pass the prestressed steel wires through the end molds, and at the same time, put the conical slurry leakage prevention plugs on the prestressed steel wires outside the end molds; Pass the prestressed steel wires through the reserved holes of the tensioning platforms at both ends of the long-line table, put conical prestressed clamping pieces on the prestressed steel wires, and tension the prestressed steel wires; Erect the tensile steel bar grid; Erect and fix the concrete top mold; Continuously pour the prepared self-compacting concrete from the vacant part above the top mold to the designed height; After the concrete strength reaches a certain strength, remove the concrete top mold, end molds and side molds; When the concrete strength is approaching the designed strength, relax the prestressed steel wires.

6. The production method of self-compacting concrete ribbed prestressed composite slabs according to claim 5, characterized in that: The self-compacting concrete is prepared by mixing cement, slag powder, fly ash, sand, gravel, water and water reducing agent; Or, the weight ratio of each material in the self-compacting concrete is: cement: slag powder: fly ash: sand: gravel: water: water reducing agent = (0.4 - 0.6): (0.1 - 0.2): (0.25 - 0.45): (1.62 - 1.89): (1.49 - 1.75): (0.32 - 0.43): (0.003 - 0.05).

7. The production method of self-compacting concrete ribbed prestressed composite slabs according to claim 6, characterized in that: The fineness modulus of the sand is 2.6 - 2.9; Or, the water reducing rate of the water reducing agent is greater than 35%, and the slump loss within 1 h should be less than 30 mm; Or, the maximum particle size of the gravel is 10 mm; Or, the cement should be of grade 42.5 or higher strength; 8. The production method of self-compacting concrete ribbed prestressed composite slabs according to claim 6, characterized in that: The mixing time of the self-compacting concrete is 2.5 - 4 minutes.

9. The production method of a self-compacting concrete ribbed prestressed composite slab according to claim 6, characterized in that: When the self-compacting concrete is poured, the slump flow should be greater than 600 mm, and the difference between the slump flow and the J-ring expansion should not be greater than 50 mm.

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