Interface formwork of ECC-gangue concrete layer in composite concrete members and preparation method thereof

Abstract

The present invention relates to an interface formwork for an ECC-gangue concrete layer in a composite concrete member and a preparation method thereof, and relates to the technical field of composite concrete members. It includes: a bottom formwork, side formworks, a steel reinforcement cage, and an anti-overflow partition board. The side formworks are installed around the top of the bottom formwork to form a frame structure with an upper opening. The steel reinforcement cage is arranged inside the frame structure, and the anti-overflow partition board is inserted into the steel reinforcement cage to equally divide the inside of the frame structure into two parts. The present invention can be used for pouring a "Z"-shaped member for a direct shear test on one side. The formwork is convenient to assemble, the process is simple, and the design of the anti-overflow partition board can effectively prevent concrete overflow while satisfying the passage of steel bars through the interface when the pouring times of the concrete on both sides are inconsistent, ensuring the quality of member pouring.

Description

Technical Field

[0001] The present invention relates to the technical field of composite concrete members, and particularly to an interface formwork for an ECC-gangue concrete layer in a composite concrete member and a preparation method therefor. Background Art

[0002] The concrete-concrete interfacial layer refers to a discontinuous casting interface inside a concrete structure formed due to different casting times or different types of concrete in two parts. The bonding performance of the concrete-concrete interfacial layer is the basis for ensuring the co-working of the two parts of concrete or two types of concrete. Once the interface fails, the performance of the structure will decrease significantly. Therefore, the safety of the concrete-concrete interfacial layer is particularly important. The influencing factors of the performance of the concrete-concrete interfacial layer include the roughness at the interface, the normal pressure, the concrete strength, the yield strength and reinforcement ratio of the steel bars penetrating the interface, the interface treatment agent, the interface moisture content, and the casting direction. Research on the performance of the concrete-concrete interfacial layer at home and abroad has been carried out for many years. The tests adopted in the research include splitting tensile tests, inclined shear tests, single-sided or double-sided direct shear tests, etc. Among them, the "Z"-shaped member used in the single-sided direct shear test is widely adopted. The "Z"-shaped member prepared by the current ECC-gangue concrete layer interface formwork cannot prevent concrete overflow while allowing the interface to pass through steel bars. Summary of the Invention

[0003] The main purpose of the present invention is to provide an interface formwork for an ECC-gangue concrete layer in a composite concrete member and a preparation method therefor to solve the above problems.

[0004] To achieve the above object, the present invention provides an interface formwork for an ECC-gangue concrete layer in a composite concrete member, including: a bottom formwork, side formworks, a steel reinforcement cage, and an anti-overflow partition. The side formworks are installed around the top of the bottom formwork to form a frame structure with an upper opening. The steel reinforcement cage is arranged inside the frame structure, and the anti-overflow partition is inserted into the steel reinforcement cage for equally dividing the inside of the frame structure into two parts.

[0005] Further, two equal-angle steel bars are respectively and parallelly welded to the bottom surface of the bottom formwork along the length direction. Between the two parallel equal-angle steel bars, a plurality of equal-angle steel bars are welded in a direction perpendicular thereto.

[0006] Further, the side formworks include two long side formworks and two short side formworks. The upper and lower ends of the long side formworks and the short side formworks horizontally extend outwards with flanges, and stiffening ribs are fixedly welded between the two flanges.

[0007] Further, the anti-overflow partition includes a partition body and trapezoidal steel partitions. The trapezoidal steel partitions are installed on both sides of the partition body, and the trapezoidal steel partitions are connected to the long side formworks by bolts.

[0008] Furthermore, the partition body includes a cover plate, an insertion plate and a handle. Extension parts are provided at both ends of the cover plate, and the trapezoidal steel partition is installed at the bottom end of the extension part by bolts; the bottom end of the cover plate is connected to the insertion plate, and the top end is connected to the handle.

[0009] Furthermore, vertical slits are longitudinally formed on the insertion plate for the longitudinal bars of the steel reinforcement cage to pass through.

[0010] Furthermore, rubber strips are fixed on both sides of the vertical slits by bolts to form an elastic automatically closing vertical slit.

[0011] A preparation method for the interface formwork of the ECC-gangue concrete layer in a composite concrete member includes the following steps:

[0012] S1. Assemble the bottom formwork and the side formwork to form a formwork with a frame structure. Fix the side formwork to the trapezoidal steel partition by bolts, and apply a release agent inside the formwork.

[0013] S2. Place the well-bound steel reinforcement cage, insert an anti-overflow partition at the interface, and fix the anti-overflow partition to the trapezoidal steel partition by bolts.

[0014] S3. After pouring the concrete on one side, place it on a magnetic concrete vibrating table to vibrate and form.

[0015] S4. After the concrete on one side begins to set, remove the bolts, remove the anti-overflow partition, and perform interface treatment; after the treatment is completed, pour the concrete on the other side, place it on a magnetic concrete vibrating table to vibrate and form.

[0016] S5. After the concrete begins to set, remove the formwork. First, remove the four-side side formwork, then separate the concrete member from the bottom formwork, and then move it to the curing room.

[0017] Furthermore, the interface treatment method in S4 includes: rough treatment, wetting treatment and treatment with an interface treatment agent.

[0018] The beneficial effects of the present invention are as follows:

[0019] The anti-overflow partition of the present invention is inserted into the steel reinforcement cage, dividing the inside of the frame structure into two equal parts. It can be used for pouring the "Z"-shaped member for the direct shear test on one side. The formwork assembly is convenient and the process is simple. The design of the anti-overflow partition can effectively prevent the concrete from overflowing while ensuring that the interface passes through the steel bars when the pouring times of the concrete on both sides are inconsistent, guaranteeing the quality of the member pouring. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic structural diagram of the present invention;

[0021] Figure 2 This is a schematic diagram of the installation structure of the trapezoidal steel partition and the frame structure of the present invention;

[0022] Figure 3 This is a schematic diagram of the structure for pouring concrete on one side of the formwork of the present invention;

[0023] Figure 4 This is a schematic diagram of the structure after the partition body is disassembled in the present invention;

[0024] Figure 5 This is a schematic diagram of the structure for pouring concrete on the other side of the formwork of the present invention;

[0025] Figure 6 This is a schematic diagram of the structure of the "Z"-shaped member formed by the formwork of the present invention;

[0026] Figure 7 This is a schematic diagram of the bottom formwork of the present invention;

[0027] Figure 8 This is a schematic diagram of the long-side formwork of the present invention;

[0028] Figure 9 This is a schematic diagram of the short-side formwork of the present invention;

[0029] Figure 10 This is a schematic diagram of the anti-overflow partition of the present invention;

[0030] Figure 11 This is a schematic diagram of the trapezoidal steel partition of the present invention.

[0031] Among them, in the figure: 1. Bottom formwork, 2. Side formwork, 3. Steel reinforcement cage, 4. Anti-overflow partition, 5. Equal-angle steel, 6. Long-side formwork, 7. Short-side formwork, 8. Flange; 9. Stiffening rib, 10. Partition body, 11. Trapezoidal steel partition, 12. Cover plate, 13. Insertion plate, 14. Handle, 15. Rubber strip. Detailed implementation manners

[0032] To achieve the above-mentioned purposes and effects, the technical means and structures adopted by the present invention will be described in detail in combination with the accompanying drawings for the preferred embodiments of the present invention to illustrate their features and functions.

[0033] Embodiment 1

[0034] As Figures 1-11 shown, the present invention provides an interface formwork for the ECC-gangue concrete layer in a composite concrete member, including: a bottom formwork 1, a side formwork 2, a steel reinforcement cage 3, and an anti-overflow partition 4. The side formwork 2 is installed on the periphery of the top of the bottom formwork 1 to form a frame structure with an upper opening. The steel reinforcement cage 3 is arranged inside the frame structure, and the anti-overflow partition 4 is inserted into the steel reinforcement cage 3 for equally dividing the inside of the frame structure into two parts.

[0035] In this embodiment, two equal - angle steel bars 5 are welded in parallel along the length direction of the bottom surface of the bottom mold 1, lifting the bottom mold 1 off the ground, which facilitates operations such as bolt connection and handling of the bottom mold 1; between the two parallel equal - angle steel bars 5, five equal - angle steel bars are welded in a direction perpendicular to them, increasing the contact area between the mold and the ground and facilitating the use of a magnetic - type concrete vibrating table.

[0036] The side mold 2 includes two long - side molds 6 and two short - side molds 7. The upper and lower ends of the long - side mold 6 and the short - side mold 7 horizontally extend outwards with flanges 8 of a certain width. Stiffening ribs 9 are fixedly welded between the two flanges 8, thereby increasing the structural strength.

[0037] The overflow - prevention partition 4 includes a partition body 10 and trapezoidal steel partitions 11. The trapezoidal steel partitions 11 are installed on both sides of the partition body 10. The trapezoidal steel partitions 11 are connected to the long - side mold 6 by bolts, reserving space for displacement during test loading of the cast - formed component. The design of the partition body 10 enables the form of the concrete layer - to - layer interface to be flexibly variable. Steel partitions of flat, arc - shaped, broken - line - shaped, grooved and other shapes can be made according to needs, which are used to form different types of interfaces between ECC - coal gangue concrete layers.

[0038] The partition body 10 includes a cover plate 12, an insertion plate 13 and a handle 14. Extension parts are provided at both ends of the cover plate 12, and bolt holes are reserved in the extension parts. The trapezoidal steel partition 11 is installed at the bottom end of the extension part by bolts; the bottom end of the cover plate 12 is connected to the insertion plate 13, and the top end is connected to the handle 14. Since the overflow - prevention partition 4 is inserted after the steel reinforcement cage 3 is placed, vertical slits are longitudinally formed in the insertion plate 13 for the longitudinal bars of the steel reinforcement cage 3 to pass through. In order to prevent concrete from overflowing from the vertical slits after pouring concrete on one side, rubber strips 15 are fixed on both sides of the vertical slits by bolts, forming an elastic automatic - closing vertical slit. After the overflow - prevention partition 4 is inserted, due to the elasticity of the rubber strips 15, the vertical slit can allow the passage of steel bars and can also fill the excess gap, preventing concrete overflow.

[0039] The "Z"-shaped component formed by using the template of the present invention can be used to explore the performance of the transitional bonding interface between ECC and coal gangue concrete. The concrete-concrete interfacial layer widely exists in concrete structures. The repair of concrete structures, the construction joints and post-cast strips formed by the segmented pouring of mass concrete will all form a large number of concrete-concrete interfaces. The present invention can be used to study the interfacial performance between new and old concretes and between two different types of concretes, improve the problem of a single concrete connection interface, and meet the concrete-concrete interfacial layers formed under various conditions. Moreover, the present invention can contribute to the research on the interfacial performance between precast components and cast-in-place components, conforming to the general trend of vigorously promoting precast concrete structures. Through the flexible design of the partition body in the template of the present invention, various types of interfaces can be formed. Through experiments, a reasonable interface design with the highest shear resistance and bonding efficiency between precast components and cast-in-place components can be proposed, providing a research basis for the popularization and application of precast concrete.

[0040] The present invention has the characteristics of sufficient stiffness and stability, convenient formwork assembly, simple procedures, fast construction speed, and tight joints. The anti-overflow partition is inserted into the steel reinforcement cage, dividing the interior of the frame structure into two equal parts, and can be used for pouring the "Z"-shaped component for single-sided direct shear test. The formwork assembly is convenient and the procedures are simple. The design of the anti-overflow partition can effectively prevent concrete overflow while satisfying the passage of steel bars through the interface when the concrete pouring times on both sides are inconsistent, ensuring the quality of component pouring.

[0041] Example 2

[0042] The present invention also provides a preparation method for the interface formwork of the ECC-coal gangue concrete layer in a composite concrete component, including the following steps:

[0043] S1. Assemble the bottom formwork and the side formwork to form a formwork for the frame structure, fix the side formwork and the trapezoidal steel partition by bolts, and apply a release agent inside the formwork;

[0044] S2. Place the well-tied steel reinforcement cage, insert the anti-overflow partition at the interface, and fix the anti-overflow partition and the trapezoidal steel partition by bolts;

[0045] S3. After pouring the concrete on one side, place it on a magnetic concrete vibrating table to vibrate and form;

[0046] S4. After the concrete on one side begins to set, remove the bolts, remove the anti-overflow partition, and perform interface treatment; after the treatment is completed, pour the concrete on the other side, place it on a magnetic concrete vibrating table to vibrate and form; the methods of interface treatment include: rough treatment (including chiseling, water jet, etc.), wetting treatment, and treatment with an interface treatment agent, etc.

[0047] For S5, remove the formwork after the concrete begins to set. First, remove the side formworks around the four sides, then separate the concrete component from the bottom formwork, and then move it to the curing room.

[0048] The construction process of the present invention has simple procedures and strong operability and feasibility. It can be used to fabricate two different types of test components for the shear performance of concrete interfaces. For example, for the ECC-gangue concrete transition interface of the ECC-reinforced gangue concrete beam-column joint, study its shear performance and the optimal design of the interface type, promote the application of gangue in concrete, alleviate the environmental impact of gangue accumulation and the pressure of aggregate mining in the construction industry, and promote the comprehensive utilization of industrial solid wastes. This formwork can fabricate partitions of various shapes and study the performance of the concrete interlayer interfaces with different interface types and treatment methods. The concrete-concrete interface widely exists in concrete structures, such as the repair of damaged concrete structures in roads, bridges, and buildings. The present invention can be used to study the influencing factors of the performance, shear transfer mechanism, and bonding performance of the interface between new and old concrete and between two different types of concrete layers.

[0049] The above are only preferred embodiments of the present invention, and do not impose any limitation on the technical scope of the present invention. Therefore, any minor modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. An interface formwork for the ECC-gangue concrete layer in a composite concrete member, characterized in that Comprising: A bottom mold, side molds, a steel reinforcement cage, and an anti-overflow partition. The side molds are installed around the top of the bottom mold to form a frame structure with an upper opening. The steel reinforcement cage is disposed within the frame structure. The anti-overflow partition is inserted into the steel reinforcement cage and is used to equally divide the interior of the frame structure into two parts for casting a "Z"-shaped member for a direct shear test on one side. Two equal-angle steel bars are welded in parallel along the length direction of the bottom surface of the bottom mold. Between the two parallel equal-angle steel bars, a plurality of equal-angle steel bars are welded in a direction perpendicular thereto. The side molds include two long side molds and two short side molds. Flanges extend horizontally outward from the upper and lower ends of the long side molds and the short side molds. Stiffening ribs are fixedly welded between the two flanges. The anti-overflow partition includes a partition body and trapezoidal steel partitions. The trapezoidal steel partitions are installed on both sides of the partition body. The trapezoidal steel partitions are connected to the long side molds by bolts. The partition body includes a cover plate, an insertion plate, and a handle. Extension portions are provided at both ends of the cover plate. The trapezoidal steel partitions are installed at the bottom ends of the extension portions by bolts. The bottom end of the cover plate is connected to the insertion plate, and the top end is connected to the handle.

2. The interface formwork of the ECC-gangue concrete layer in a combined concrete member as described in claim 1, wherein, Vertical slits are longitudinally formed on the insertion plate for the longitudinal bars of the steel reinforcement cage to pass through.

3. The interface formwork of the ECC-gangue concrete layer in a combined concrete member as claimed in claim 2, wherein Rubber strips are fixed by bolts on both sides of the vertical slits to form an elastic automatically closing vertical slit.

4. The preparation method of the interface formwork of the ECC-gangue concrete layer in a combined concrete member according to any one of claims 1-3, characterized in that, Including the following steps: S1. Assemble the bottom mold and the side molds to form a mold of the frame structure. Fix the side molds and the trapezoidal steel partitions by bolts, and apply a release agent inside the mold. S2. Place the well-tied steel reinforcement cage, insert the anti-overflow partition at the interface, and fix the anti-overflow partition and the trapezoidal steel partitions by bolts. S3. After pouring the concrete on one side, place it on a magnetic concrete vibrating table to vibrate and form it. S4. After the concrete on one side begins to set, remove the bolts, remove the anti-overflow partition, and perform interface treatment. After the treatment is completed, pour the concrete on the other side, place it on a magnetic concrete vibrating table to vibrate and form it. S5. After the concrete begins to set, remove the formwork. First, remove the side molds around the four sides, then separate the concrete member from the bottom mold, and then move it to the curing room.

5. The preparation method of the interface formwork of the ECC-gangue concrete layer in a combined concrete member as described in claim 4, characterized in that, The method of interface treatment in S4 includes: rough treatment, wetting treatment, and treatment with an interface treatment agent.

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