One-time pouring forming method for blast furnace foundation

Abstract

The invention provides a one-time pouring forming method for a blast furnace foundation. The one-time pouring forming method comprises the following steps that S1, a bottom outer formwork and a bottom reinforcement cage of a bottom foundation are arranged; s2, a connecting support is arranged at the connecting position of the bottom foundation and an upper foundation above the bottom foundation, and the lower portion of the connecting support is inserted into the bottom reinforcement cage and fixed to the bottom reinforcement cage; s3, an upper reinforcement cage of the upper foundation is arranged, the upper portion of the connecting support is inserted into the upper reinforcement cage and fixedly connected with the upper reinforcement cage, and an upper outer formwork is arranged outside the upper reinforcement cage; and S4, concrete is poured into the bottom outer formwork, and concrete is poured into the upper outer formwork after concrete pouring in the bottom outer formwork is completed. According to the method, the blast furnace foundation can be successfully poured at a time without being poured at intervals, the whole blast furnace foundation is firm, the construction efficiency is improved, and the construction time is saved.

Description

Technical Field

[0001] The invention relates to the technical field of blast furnace construction, and more specifically to a one-time casting and molding method for a blast furnace foundation. Background Art

[0002] At present, in the construction process of iron-making blast furnace foundation, large-volume concrete pouring has always been the focus and difficulty of blast furnace foundation construction (generally, the concrete pouring volume of large and medium-sized blast furnace foundation is 2000m 3 Up to 4000m 3 ). The traditional blast furnace foundation design is that the lower part is a rectangular bottom plate foundation, and the upper part is a truncated cone heat-resistant base squat foundation. Generally, the vertical height from the bottom to the top of a large and medium-sized blast furnace foundation is between 7 meters and 10 meters.

[0003] Because the height of the truncated cone hanging formwork for the upper truncated cone heat-resistant foundation is generally 5 to 7 meters, it is easy to cause slurry overflow, mold expansion, and loose vibration during the concrete pouring process. It is difficult to cast the entire foundation at one time, so the construction is usually segmented. The bottom plate foundation and the truncated cone heat-resistant foundation are poured twice. The lower bottom plate foundation is poured first, and the concrete is C30 ordinary concrete. After an interval of 7-10 days, the truncated cone heat-resistant foundation of the upper cylinder is poured. The concrete is C30 heat-resistant concrete with a height of more than 5m. There is a construction joint between the bottom plate foundation and the truncated cone heat-resistant foundation. The construction joint is constructed by chiseling and cleaning the concrete foundation poured first, and then inserting a number of Φ18mm-24mm thick dowels. The dowel anchor length should be 35d, and the length left outside should be 35d. The vertical and horizontal spacing is 500mm, and they are staggered. Then, 300mm to 500mm high cement slurry is set horizontally on the bottom foundation. The existing construction method is prone to cold joints, which makes the joint surface between the two foundation layers weak, and also causes a long overall construction period and increased construction costs. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide a one-time casting and forming method for a blast furnace foundation, so that the blast furnace foundation can be cast successfully in one time without the need for casting in intervals. The blast furnace foundation is overall firm, the construction efficiency is improved, and the construction time is saved.

[0005] The present invention provides a one-time casting method for a blast furnace foundation, comprising the following steps:

[0006] S1: Set the bottom outer formwork and bottom reinforcement cage of the bottom foundation;

[0007] S2: a connecting bracket is arranged at a position where the bottom foundation is connected to an upper foundation above the bottom foundation, and a lower portion of the connecting bracket is inserted into the bottom steel cage and fixed to the bottom steel cage;

[0008] The cross-sectional area of ​​the connecting bracket is not greater than the cross-sectional area of ​​the upper foundation, and the height of the connecting bracket is greater than the height of the bottom foundation;

[0009] S3: an upper reinforcement cage of the upper foundation is arranged, the upper part of the connecting bracket is inserted into the upper reinforcement cage and is connected and fixed to the upper reinforcement cage, and an upper outer formwork is arranged outside the upper reinforcement cage;

[0010] S4: pouring concrete into the bottom outer formwork. After the concrete pouring in the bottom outer formwork is completed, pouring concrete into the upper outer formwork.

[0011] In step S2, the connecting bracket includes vertical steels evenly arranged in rows and columns within the cross-sectional area of ​​the upper reinforcement cage, and the vertical steels are respectively inserted into corresponding grids of the horizontal grid plate and welded to the corners of the corresponding grids.

[0012] The length of the vertical steel is the sum of the heights of the bottom steel cage and the upper steel cage.

[0013] The cross section is circular, and the outer circumference of the horizontal grid plate is circular.

[0014] The horizontal grid plate includes angle steels or steel bars that are vertically welded to form the grid plate.

[0015] At least three horizontal grid plates are arranged along the vertical steel, two of which are evenly arranged in the upper steel cage, and one horizontal grid plate is arranged in the bottom steel cage. The bottom steel cage and the upper steel cage are respectively connected and fixed to the corresponding horizontal grid plates.

[0016] The vertical steel is angle steel or steel bar, and the vertical steel is connected and fixed to the steel bars of the adjacent bottom steel cage / upper steel cage.

[0017] The side length of the grid is 1 m.

[0018] In step S4, ordinary concrete is poured into the bottom outer formwork, and heat-resistant concrete is poured into the upper outer formwork.

[0019] In step S2, a first plastic cooling coil is arranged in the bottom steel cage;

[0020] In step S3, two second plastic cooling coils are evenly arranged in the height direction in the upper steel cage.

[0021] The one-time casting method for the blast furnace foundation according to the present invention adopts a connection bracket set at the connection position of the bottom foundation and the upper foundation, and the two ends of the connection bracket are respectively fixed to the bottom steel cage and the upper steel cage. The connection bracket makes the bottom steel cage and the upper steel cage into a whole, and the bottom foundation and the upper foundation are cast at one time. The connection bracket reinforces the connection between the two foundations, and there is no gap between the two foundations. The present invention realizes the one-time casting and forming of a large-volume heterogeneous foundation, saves construction time, improves the stability of the entire foundation, avoids construction joints, avoids the generation of secondary casting cold joints, and the construction quality is easier to control and ensure.

[0022] In order to achieve the above and related purposes, one or more aspects of the present invention include features that will be described in detail later and are particularly pointed out in the claims. The following description and the accompanying drawings describe some exemplary aspects of the present invention in detail. However, these aspects indicate only some of the various ways in which the principles of the present invention can be used. In addition, the present invention is intended to include all of these aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] By referring to the following description in conjunction with the accompanying drawings, and with a more comprehensive understanding of the present invention, other objects and results of the present invention will become more apparent and easy to understand. In the accompanying drawings:

[0024] Figure 1 This is a flow chart of a one-time casting method for a blast furnace foundation according to Example 1 of the present invention;

[0025] Figure 2 This is a schematic diagram of the application of the connecting bracket according to Embodiment 1 of the present invention;

[0026] Figure 3 is a side view of a connecting bracket according to Embodiment 1 of the present invention;

[0027] Figure 4 is a top view of a connecting bracket according to Embodiment 1 of the present invention;

[0028] Figure 5 is a schematic diagram of a cooling structure according to Embodiment 2 of the present invention;

[0029] Figure 6 is a top view of a first cooling coil according to Embodiment 2 of the present invention;

[0030] Figure 7 is a top view of a second cooling coil according to Embodiment 2 of the present invention;

[0031] Among them, 1-bottom foundation, 11-bottom outer formwork, 12-bottom steel cage, 2-upper foundation, 21-upper steel cage, 22-upper outer formwork, 3-connecting bracket, 31-vertical steel, 32-horizontal grid plate, 4-first cooling coil, 5-second cooling coil;

[0032] The same reference numerals throughout the drawings indicate similar or corresponding features or functions. DETAILED DESCRIPTION

[0033] In the following description, for the purpose of illustration, in order to provide a comprehensive understanding of one or more embodiments, many specific details are set forth. However, it is apparent that these embodiments may also be implemented without these specific details. In other examples, for ease of describing one or more embodiments, known structures and devices are shown in the form of block diagrams.

[0034] The present invention can be subjected to various changes and can have various embodiments, and specific embodiments are illustrated and described in the accompanying drawings. However, the present invention is not limited to the specific implementation, and all changes, equivalents and substitutes falling within the concept and technical scope of the present invention are included, and should be understood to be included.

[0035] Ordinal terms such as first, second, etc. may be used to describe various constituent elements, but the constituent elements are not limited to the terms. The terms are only used to distinguish one constituent element from another constituent element. For example, without departing from the scope of the claims of the present invention, the second constituent element may be named as the first constituent element, and similarly, the first constituent element may be named as the second constituent element. The terms and / or include a combination of multiple associated items or a certain item among multiple associated items.

[0036] It should be understood that when a certain component is mentioned to be "connected" or "contacted" with other components, this includes not only the case where it is directly connected or contacted with other components, but also the case where other components exist in between. Conversely, when a certain component is mentioned to be "directly connected" or "directly contacted" with other components, it should be understood that there are no other components in between.

[0037] In the description of the embodiments, when it is described that a certain component is formed "on or under" another component, on or under includes two components directly contacting each other or at least one other component is arranged and formed between the two components. Moreover, when it is expressed as on or under, it refers to not only the upper direction but also the lower direction based on a certain component.

[0038] The terms used in this application are only used to illustrate specific embodiments and are not intended to limit the present invention. Unless the context clearly provides otherwise, singular expressions include plural expressions. In this application, it should be understood that terms such as "including" or "having" are used to specify the presence of features, numbers, steps, operations, constituent elements, parts or combinations thereof recorded in the specification, and do not preclude the presence or additional possibility of one or more other features, numbers, steps, operations, constituent elements, parts or combinations thereof.

[0039] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as those generally understood by those skilled in the art. Terms defined in commonly used dictionaries should be interpreted as having the same meaning as in the context of the relevant technology, and if not clearly defined in this application, they should not be interpreted as ideal or overly formal meanings.

[0040] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0041] Example 1

[0042] like Figure 1-Figure 4 As shown together, the one-time casting and forming method of the blast furnace foundation proposed in this embodiment can be used for casting the concrete foundation of the blast furnace in one go, and can also be used for casting other concrete foundations with upper and lower sections.

[0043] The one-time casting method for blast furnace foundation comprises the following steps:

[0044] S1: Setting the bottom outer formwork 11 and the bottom reinforcement cage 12 of the bottom foundation 1.

[0045] The concrete foundation of a steel plant's blast furnace is generally huge in size, including a bottom foundation 1 at the bottom and an upper foundation 2 in the middle of the bottom foundation 1. The bottom foundation 1 is approximately a square table with a side length of more than 20 meters and a height of about 4 meters. The upper foundation 2 is cylindrical in shape with a diameter of more than 10 meters and a height of more than 5 meters.

[0046] During construction, the bottom outer formwork 11 of the bottom foundation 1 is first set, and the bottom reinforcement cage 12 is erected inside the bottom outer formwork 11. The shape and size of the bottom outer formwork 11 and the reinforcement arrangement of the bottom reinforcement cage 12 are set according to the specific conditions of the blast furnace.

[0047] S2: A connecting bracket 3 is set at the position where the bottom foundation 1 is connected to the upper foundation 2 above it, and the lower part of the connecting bracket 3 is inserted into the bottom steel cage 12 and fixed to the bottom steel cage 12; the cross-sectional area of ​​the connecting bracket 3 is not larger than the cross-sectional area of ​​the upper foundation 2, and the height of the connecting bracket 3 is larger than the height of the bottom foundation 1.

[0048] After pouring, the two ends of the connecting bracket 3 are respectively fixed in the upper foundation 2 and the bottom foundation 1, which can play the role of connecting and reinforcing the two.

[0049] The outer dimensions of the connecting bracket 3 should be designed according to the dimensions of the upper foundation 2, and the outer periphery of the connecting bracket 3 should have a protective layer distance from the outer wall of the upper foundation 2. The connecting bracket 3 can be composed of a plurality of rods, and the length of the connecting bracket 3 inserted into the bottom steel cage 12 should be long enough, and the length inserted into the upper foundation 2 should be long enough to ensure a firm connection between the upper and lower foundations.

[0050] The connection bracket 3 is generally vertically arranged at the center of the bottom reinforcement cage 12. The connection bracket 3 is installed according to the construction conditions of the bottom reinforcement cage 12, and the connection bracket 3 can be installed during the erection process of the bottom reinforcement cage 12.

[0051] S3: an upper reinforcement cage 21 of the upper foundation 2 is set, the upper part of the connecting bracket 3 is inserted into the upper reinforcement cage 21 and is connected and fixed to the upper reinforcement cage 21, and an upper outer formwork 22 is set outside the upper reinforcement cage 21.

[0052] After the bottom steel cage 12 and the connecting bracket 3 are fixed, the upper steel cage 21 is arranged according to the specific conditions of the construction, and the portion of the connecting bracket 3 that is higher than the lower steel cage is fixed to the upper steel cage 21, and the fixing method can be welding or binding. The upper outer formwork 22 is arranged above the bottom steel cage 12 and surrounds the outside of the upper steel cage 21.

[0053] When installing the upper reinforcement cage 21 , the connection bracket 3 should be arranged in the upper reinforcement cage 21 in consideration of the situation of the connection bracket 3 .

[0054] The bottom reinforcement cage 12 and the upper reinforcement cage 21 of the connecting bracket 3 are integrated into one, providing a stable support.

[0055] S4: pouring concrete into the bottom outer formwork 11. After the concrete pouring in the bottom outer formwork 11 is completed, concrete is then poured into the upper outer formwork 22.

[0056] After the outer formwork is installed, concrete pouring begins. First, concrete is poured from the upper open side of the bottom outer formwork 11. After nearly 2,000 cubic meters of concrete is poured in the bottom outer formwork 11, it is vibrated and compacted repeatedly, and then the concrete foundation is leveled and finished. This time is about 4-6 hours, so that the concrete bottom concrete has a certain strength, and then pouring begins in the upper outer formwork 22. The pouring speed cannot be too fast to avoid forming too much pressure on the concrete below. During the pouring process, the concrete below slightly forms a strength that can withstand the concrete poured later, and is combined with the concrete poured later. The pouring process can be determined according to the specific situation to ensure that the pouring is dense and flat. After the concrete pouring in the upper outer formwork 22 is completed, the concrete of the upper foundation 2 and the bottom foundation 1 form a whole without gaps.

[0057] After the concrete reaches a suitable hardness, the bottom outer formwork 11 and the upper outer formwork 22 are removed to obtain a complete concrete foundation, and the internal connecting bracket 3 firmly connects the upper and lower foundations.

[0058] The lower end of the upper outer formwork 22 leaves a circle of fine cracks on the upper surface of the concrete of the bottom foundation 1, which is filled with concrete.

[0059] In a specific embodiment of the present invention, in step S2, the connecting bracket 3 may include vertical steels 31 uniformly arranged in rows and columns within a set range, and the vertical steels 31 may be angle steels or steel bars, and the specifications of the angle steels or steel bars are determined according to the specific construction conditions. In order to firmly connect all the vertical steels 31, the vertical steels 31 are respectively inserted into the corresponding grids of the horizontal grid plate 32 and welded to the corners of the corresponding grids, and all the vertical steels 31 are connected together through the horizontal grid plate 32. The set range can be the range of the cross section of the upper steel cage 21.

[0060] A number of vertical steels 31 are evenly arranged within the cross section of the upper steel cage 21, and the vertical steels 31 are firmly fixed together by horizontal grid plates 32, so that they will not be skewed or displaced during the pouring process. A large number of vertical steels are inserted in the upper and lower steel cages, ensuring a firm connection between the upper and lower foundations after pouring. The cross section formed by all vertical steels 31 is the same as the cross section of the upper steel cage 21, and the vertical steels 31 can also be protected by the steel protective layer.

[0061] The spacing between adjacent vertical steels 31 is determined according to the specific construction conditions. In this embodiment, the spacing between adjacent vertical steels 31 in the same row / column is about 1 m, and the grid side length of the horizontal grid plate 32 is about 1 m.

[0062] In order to ensure that the vertical steel 31 has sufficient length to be inserted into the upper and lower steel cages, in this embodiment, the length of the vertical steel 31 may be approximately the sum of the heights of the bottom steel cage 12 and the upper steel cage 21 .

[0063] The cross section of the upper foundation 2 can be square or circular. In a specific embodiment of the present invention, the cross section is circular, and the outer periphery of the horizontal grid plate 32 is circular. The shape of all vertical steels 31 is determined according to the shape of the upper foundation 2. The upper foundation 2 is cylindrical, the cross section of the upper steel cage 21 is circular, the shape of the vertical steels 31 is set to be cylindrical, and the horizontal grid plate 32 is also circular accordingly.

[0064] In a specific embodiment of the present invention, the horizontal grid plate 32 may include angle steels or steel bars that are welded perpendicularly to each other to form the grid plate. The length and welding method of each angle steel or steel bar are determined according to the cross-sectional conditions of the upper steel cage 21. If the cross-sectional conditions of the upper steel cage 21 are circular and the horizontal grid plate 32 is circular, the angle steels or steel bars gradually become shorter from the middle to the edge.

[0065] In a specific embodiment of the present invention, in order to further stabilize and strengthen all vertical steels 31, at least three horizontal grid plates 32 are arranged along the vertical steels 31, two horizontal grid plates 32 are evenly located in the upper steel cage 21, and one horizontal grid plate 32 is located in the bottom steel cage 12, and the bottom steel cage 12 and the upper steel cage 21 are respectively connected and fixed to the corresponding horizontal grid plates 32.

[0066] Since the steel bars in the upper steel cage 21 are relatively sparse, two horizontal grid plates 32 are fixed to the vertical steel 31 part in the upper steel cage 21. The horizontal grid plates 32 can be connected and fixed to the steel bars of the upper steel cage 21, and the vertical steel 31 can also be connected and fixed to the adjacent steel bars, so that the upper part of the connecting bracket 3 is firmly fixed.

[0067] Since the steel bars of the bottom steel cage 12 are denser, a horizontal grid plate 32 can be set in the bottom steel cage 12. The horizontal grid plate 32 can be connected and fixed to the steel bars of the bottom steel cage 12, and the vertical steel 31 can also be connected and fixed to the adjacent steel bars, and the lower part of the connecting bracket 3 is firmly fixed.

[0068] During the construction of the bottom reinforcement cage 12, the lower part of the connecting bracket 3 can be installed at the corresponding position of the bottom reinforcement cage 12. After the construction of the bottom reinforcement cage 12 is completed, the upper part of the connecting bracket 3 protrudes from the bottom reinforcement cage 12. During the construction of the upper reinforcement cage 21, the upper part of the connecting bracket 3 is connected and fixed to the reinforcement of the upper reinforcement cage 21. The connecting bracket 3 connects the bottom reinforcement cage 12 and the upper reinforcement cage 21 into a whole.

[0069] In a specific embodiment of the present invention, since the upper part of the blast furnace foundation needs to be heat-resistant, in step S4, ordinary concrete is poured in the bottom outer formwork 11, and heat-resistant concrete is poured in the upper outer formwork 22. The upper foundation 2 formed by the heat-resistant concrete can withstand the heat of the blast furnace.

[0070] Example 2

[0071] like Figure 5-Figure 7 As shown together, the one-time casting method for the blast furnace foundation provided in this embodiment is based on Example 1, and cooling coils are added to the upper and lower foundations to solve the heat dissipation problem of concrete. The cooling coils are buried inside the concrete during the pouring process, and the cold water flowing in the pipes takes away part of the heat inside the concrete, thereby reducing the internal temperature of the concrete and achieving the purpose of controlling the internal temperature of the concrete.

[0072] Specifically, in step S2, since the height of the bottom foundation 1 is relatively low, a layer of plastic first cooling coil 4 is arranged in the bottom steel cage 12, and cold water circulates in the first cooling coil 4 to cool the concrete.

[0073] The first cooling coil 4 can be composed of two curved serpentine plastic coils on the same horizontal plane, and the water inlet and outlet ends of each plastic coil extend out of the bottom outer template 11. The first cooling coil 4 bent on the cross section of the bottom steel cage 12 can cool every area of ​​the cross section.

[0074] In step S3, since the height of the upper foundation 2 is higher than the bottom foundation 1, two layers of plastic second cooling coils 5 are evenly arranged in the upper steel cage 21 along the height direction, and cold water circulates in the second cooling coils 5 to cool the concrete.

[0075] The second cooling coil 5 can be composed of two curved serpentine plastic coils on the same horizontal plane, and the water inlet and outlet ends of each plastic coil extend out of the upper outer template 22. The second cooling coil 5 bent on the cross section of the upper steel cage 21 can cool every area of ​​the cross section.

[0076] Each serpentine plastic coil is formed by bending a pipe in a circuitous manner, has no seams and will not leak, and has low material costs.

[0077] As described above, the one-time pouring and forming method of the blast furnace foundation according to the present invention is described by way of example with reference to the accompanying drawings. However, it should be understood by those skilled in the art that various improvements can be made to the one-time pouring and forming method of the blast furnace foundation proposed by the present invention without departing from the content of the present invention. Therefore, the protection scope of the present invention should be determined by the content of the attached claims.

Claims

1. A one-time casting method for a blast furnace foundation, characterized in that: The following steps are involved: S1: Set the bottom outer formwork and bottom reinforcement cage of the bottom foundation; S2: a connecting bracket is arranged at a position where the bottom foundation is connected to an upper foundation above the bottom foundation, and a lower portion of the connecting bracket is inserted into the bottom steel cage and fixed to the bottom steel cage; The cross-sectional area of ​​the connecting bracket is not greater than the cross-sectional area of ​​the upper foundation, and the height of the connecting bracket is greater than the height of the bottom foundation; S3: an upper reinforcement cage of the upper foundation is arranged, the upper part of the connecting bracket is inserted into the upper reinforcement cage and is connected and fixed to the upper reinforcement cage, and an upper outer formwork is arranged outside the upper reinforcement cage; S4: pouring concrete into the bottom outer formwork. After the concrete pouring in the bottom outer formwork is completed, pouring concrete into the upper outer formwork.

2. The one-time casting method for blast furnace foundation according to claim 1, characterized in that: In step S2, the connecting bracket includes vertical steels evenly arranged in rows and columns within the cross-sectional area of ​​the upper reinforcement cage, and the vertical steels are respectively inserted into corresponding grids of the horizontal grid plate and welded to the corners of the corresponding grids.

3. The one-time casting method for blast furnace foundation according to claim 2, characterized in that: The length of the vertical steel is the sum of the heights of the bottom steel cage and the upper steel cage.

4. The one-time casting method for blast furnace foundation according to claim 2, characterized in that: The cross section is circular, and the outer circumference of the horizontal grid plate is circular.

5. The one-time casting method for blast furnace foundation according to claim 2, characterized in that: The horizontal grid plate includes angle steels or steel bars that are vertically welded to form the grid plate.

6. The one-time casting method for blast furnace foundation according to claim 2, characterized in that: At least three horizontal grid plates are arranged along the vertical steel, two of which are evenly arranged in the upper steel cage, and one horizontal grid plate is arranged in the bottom steel cage. The bottom steel cage and the upper steel cage are respectively connected and fixed to the corresponding horizontal grid plates.

7. The one-time casting method for blast furnace foundation according to claim 2, characterized in that: The vertical steel is angle steel or steel bar, and the vertical steel is connected and fixed to the steel bars of the adjacent bottom steel cage / upper steel cage.

8. The one-time casting method for blast furnace foundation according to claim 2, characterized in that: The side length of the grid is 1 m.

9. The one-time casting method for blast furnace foundation according to claim 1, characterized in that: In step S4, ordinary concrete is poured into the bottom outer formwork, and heat-resistant concrete is poured into the upper outer formwork.

10. The one-time casting method for blast furnace foundation according to claim 1, characterized in that: In step S2, a first plastic cooling coil is arranged in the bottom steel cage; In step S3, two second plastic cooling coils are evenly arranged in the height direction in the upper steel cage.

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