WO2020186868A1

WO2020186868A1 - Bar lap joints between concrete structures, forming method therefor, and grouting monitoring element used during grouting

Info

Publication number: WO2020186868A1
Application number: PCT/CN2019/127888
Authority: WO
Inventors: 梁惠文
Original assignee: 巴马丹拿建筑及工程师有限公司
Priority date: 2019-03-21
Filing date: 2019-12-24
Publication date: 2020-09-24

Abstract

A method for forming lap joints between concrete structures. The lap joint comprises: a first shaped space (2) formed in a first concrete structure beside a first steel bar (8); a movable steel bar (3), placed in the entire first shaped space (2); and a second concrete structure, formed beside the first concrete structure and having a second steel bar (8) located beside a second shaped space (1). The second shaped space (1) is arranged substantially coaxially in correspondence to the first shaped space (2). A part of the movable steel bar (3) is placed in the first shaped space (2), and the other part thereof is placed in the second shaped space (1). The present invention also relates to a method for forming a shaped space in a concrete structure and a grouting monitoring element for monitoring whether grout is filled in a conduit.

Description

Used for steel bar overlap connection between concrete structures, its forming method and grouting monitoring element used for grouting

Technical field

The present invention provides a plurality of technologies for connecting concrete structures, which allow prefabricated elements to be quickly assembled on a construction site and can be used together to form a systematic construction technology that can cleanly, quickly and simply assemble elements on a construction site.

Background of the invention

Precast concrete structure is a structure widely used by modern architecture to quickly build multi-storey buildings such as high-rise buildings and office buildings. Precast concrete structures are produced off-site, such as a factory. Precast concrete structures often use steel bars extending from the structure to connect the steel bars of adjacent structures.

A common construction method used to connect prefabricated structures is the corrugated steel pipe grouting method, which penetrates:

1. Place a metal corrugated sleeve on the end of the precast concrete element to form a hollow conduit, or use other methods to form a hole space;

2. Rebar (such as steel bar) extended from another prefabricated or cast-in-place concrete element is called connecting rebar, and the extended length is called anchoring length, which is determined by the size of the rebar, and the anchoring of rebar with a diameter of more than 25 mm The length usually exceeds 1 meter;

3. When placing the prefabricated element in the final position, all connecting steel bars are inserted into the metal bellows;

4. Fill the space between the steel bar and the metal bellows with non-shrinkage cement grout until the grout overflows the grout outlet hole, then the structural connection is completed;

5. After completion, the main steel bar in the prefabricated element and the connecting steel bar in the metal bellows form an overlap, and the tension and pressure of the main steel bar can be transmitted to the connecting steel bar, so the two structural elements can be connected together.

The disadvantages of the above connection system are:

1. The concrete element extends the length of the steel bar, whether it is 400 mm or more than one meter, it is very long. It is very difficult to insert the connecting steel bar into the metal bellows of another prefabricated element, and it must be accurately aligned. The exposed connecting steel bars are easy to be bent during transportation and cause misalignment, which makes installation difficult. People who construct on-site often have to adjust them to the correct position.

2. The extended steel bars will increase the length of the overall prefabricated components, increase the space required for transportation, and reduce the efficiency of transportation.

3. For high-rise buildings, the content of steel bars in the wall columns is very high, and there will be a lot of connecting steel bars. It is very difficult to align all the connecting steel bars into the metal bellows.

4. The role of the metal bellows is to form a space for inserting the connecting steel bars, and there is no structural effect after grouting. The prefabricated structure requires a lot of metal bellows, which is a waste of material.

5. The method of grouting, using the cement slurry overflow grouting outlet hole as an indicator to make sure that the space between the steel bar and the metal bellows is full, which wastes the overflowing cement slurry and is unfavorable for the environmental management of the construction site.

Therefore, for connecting concrete structures such as prefabricated walls, columns, beams and slabs, it is necessary to improve the existing technology of joining concrete structures in order to achieve faster and safer construction, reduce transportation costs and simplify connection structures.

Summary of the invention

The first aspect of the present invention provides a method for connecting an improved concrete structure (for example, a precast concrete structure). In this method, the method includes:

A first shaped space is formed in the first concrete structure, and the first shaped space is arranged beside the first main steel bar of a first concrete structure;

A movable steel bar is placed in the first shaped space, and the length of the movable steel bar is shorter than the length of the first shaped space, so that the movable steel bar is completely contained in the first shaped space.

Place a second concrete structure next to the first concrete structure. The second concrete structure includes a second shaped space adjacent to the second main reinforcement of the second concrete structure. 2. The position of the shaped space is approximately coaxial with the first shaped space of the first concrete structure;

Move the movable steel bar to a position where a part of the movable steel bar is located in the first shaped space and a part is located in the second shaped space, so that the movable steel bar and The main steel bars of the first main steel bar and the second main steel bar partially overlap; and

The grout fills the first shaped space and the second shaped space.

In one embodiment, the method further includes placing a center element beside the upper surface of the movable steel bar to center the movable steel bar in the first shaped modeling space; wherein, The neutral element can be a metal spring coil.

In another embodiment, the method further includes using a lead wire for holding the movable steel bar in the first shaped space.

In another embodiment, the method further includes using a hole conduit arranged between the first shaped space and one side of the first concrete structure to receive grouting; wherein, the method can The method further includes using a lead wire, one end of the lead wire passing through the hole conduit for holding the movable steel bar in the first shaped space.

In another embodiment, the method further includes using a hole conduit arranged between the first shaped space and one side of the first concrete structure to receive grouting. In this embodiment, the method may further include using a lead wire, one end of the lead wire passing through the hole conduit for holding the movable steel bar in the first shaped space. The overlap connection may further include a second shaped space, which is arranged between the second modeling space and one side of the second concrete structure. The overlap connection may further include a grouting monitoring element, which is arranged in the second grouting path with a shape space, and the grouting monitoring element provides a display of the completion of grouting and prevents the grout from overflowing. In a specific embodiment, there are multiple grouting channels behind the grouting monitoring element and multiple perforations on the surface of the monitoring element, and the width of the multiple grouting channels narrows as they approach the monitoring surface; The surface of the grouting monitoring element can be transparent.

In another embodiment, the cancellation of the second shaped space of the second concrete structure can be replaced by a mechanical joint facing the first shaped space of the first concrete structure. In this embodiment, when the second shaped space of the second concrete structure is replaced by the mechanical joint, the movable rebar and the mechanical joint have threads respectively, and the rebar is moved and rotated. Screw the rebar into the mechanical joint.

In another embodiment, the internal former is formed by a combination of one or more round rods, square rods, or other shaped rods; the plastic polymer release layer surrounds the package in a roughly spiral pattern. The inner former is covered, the inner former is pulled out after the concrete is poured, and the anti-adhesion layer is finally pulled out to form a shaped space in the concrete structure.

The second aspect of the present invention relates to a grouting monitoring element used when grouting a prefabricated structural member, including:

A shell connected to a hole duct;

A plate body, which covers the shell and is provided with a plurality of small holes, and is provided with one or more grouting channels for the flow of grout on the back,

Wherein, the size of the small hole is designed to allow air to pass but the slurry cannot circulate.

In one embodiment, the grouting monitoring element is placed on the grouting exit hole and the key path of grouting to observe the progress of grouting.

In another embodiment, the grouting monitoring element provides an indication of the completion of grouting to prevent overflow of the grout.

In another embodiment, the width of the plurality of grouting channels narrows as they approach the monitoring surface; in addition, the surface of the grouting monitoring element may be transparent.

In another embodiment, the housing is made of plastic or metal.

In another embodiment, the disc body is made of plastic.

The third aspect of the present invention relates to a method for forming a duct with a shape space or a hole applied to a concrete structure, including:

One or more round rods, square rods, or other shaped rods are combined to form an internal former;

Wrap the inner former in a roughly spiral pattern with a release layer;

Pull out the internal former after pouring the concrete;

Finally, the anti-adhesion layer is pulled out to form a shaped space or hole conduit in the concrete structure.

In one embodiment, the material of the anti-adhesive surrounding layer is plastic, Feriron or silicone strip or steel cable.

Description of the drawings

Figure 1 is a method of an embodiment of the present invention in a prefabricated or cast-in-place manner to form a plurality of shaped spaces at the ends of a first concrete element and a second concrete element for vertically connecting the ends of the two concrete elements Schematic diagram of

Fig. 2 is a schematic diagram of the ends of two concrete elements connected in a horizontal or non-vertical connection manner by a method in an embodiment of the present invention;

Figure 3 shows another embodiment of the present invention through a set of steel reinforcement mechanical joints and threaded steel bars at the ends, and rotating the steel bars inserted into the shape space into the mechanical joints to connect two precast concrete elements;

Figure 4 shows a method of forming a shaped space corresponding to the reinforcing bar of the present invention;

Fig. 5 shows a schematic diagram of an inner former and a surround used in the method of forming a shaped space of the present invention.

Figure 6 shows an embodiment of the present invention showing the state of grout filling by a grout monitoring element arranged at the grout outlet hole (top position);

Fig. 7 shows an enlarged cross-sectional view of the grout monitoring element in Fig. 6 at the grout outlet hole.

detailed description

The present invention discloses a new type of precast concrete structure system, which is used to avoid the above-mentioned problem of connecting steel bars extending out of the structure. The invention is suitable for single precast concrete elements including columns, walls, diagonal braces, beams and slabs or other large structures such as concrete modules. According to the technology of the present invention, the shape space in the prefabricated element temporarily provides space for placing connecting steel bars (for example, straight steel bars). Generally speaking, the prefabricated element will not have the end of the connecting steel bar extending out of the structure.

Please refer to Figs. 1-2, a plurality of shaped spaces 1 are formed at one end of a first concrete element by prefabrication or casting. The formation of the shaped space 1 can be achieved by conventional methods, such as using a metal corrugated tube, or the method of using an inner former to wrap the surrounding layer disclosed in the present invention. The shaped space 1 is arranged near the main steel bar 8 of the concrete element. Another set of shaped spaces 2 is formed at one end of a second concrete element. The first concrete element is first placed at the final setting position; when pouring on site, the first concrete element is preferentially poured. When the ends of two concrete elements are joined, according to the design, the positions of the two sets of shape spaces are relative. Before installing the second precast concrete element, the connecting steel bars 3 are inserted into the shaped space corresponding to the first or second concrete element. As shown in the figure, the connecting steel bar 3 is placed in the shaped space 2 and can also be placed in another shaped space.

For horizontal element connection, as shown in Fig. 2, the connecting steel bar 3 can be firmly connected to one end of the steel bar 3 by a lead wire 5 or other suitable connectors to be positioned away from the open end with a shape space. The lead 5 passes through the shaped space 2 and exits from the joint of the two concrete elements. When necessary, the central device 4 can be placed along the length of the connecting steel bar so that the connecting steel bar 3 can be fixed in the center of the shaped space. The neutral device 4 may be a metal spring coil fixed on it along the steel bars. The metal spring coil was chosen because of its elasticity, low cost, and the characteristics of allowing mud to circulate. However, it can also choose any other device that can center the movable steel bars.

The second prefabricated element is suspended and placed so that the shaped spaces of the two elements can be matched and positioned; generally, the two shaped spaces are roughly coaxial.

For vertically connected prefabricated components, the connecting steel bars can be temporarily supported in the upper component, and the lead wires of the connecting steel bars 3 can be released to move downward and inserted into the shaped space of the lower prefabricated component. The connecting bars 3 will fall into the shaped space of the lower prefabricated element.

For prefabricated components with horizontal or non-vertical connections (for example, inclined connections), as shown in Figure 2, under the condition that gravity cannot be used to move the connecting steel bars, one can be firmly attached to the end of the connecting steel bar by stretching, and two The leads of the indirect seams of the prefabricated components move the connecting steel bars to the shaped space of the opposing prefabricated components (as shown in Figure 2). In addition, it is also possible to use a bendable rod or device to push one end of the steel bar from a small hole (conduit) 7 to move the connecting steel bar temporarily set in the shaped space 2 to the shaped space 3. The small hole 7 is prefabricated The element is used for the holes set in the grouting operation. The consideration of the length design of the connecting steel bar is that when it is pulled or dropped to the final position, it still has a sufficient overlapping length 9 with the main steel bar 8. After the non-shrinkage cement is poured and the connected shaped space is filled, the connecting steel bars can effectively overlap with the main steel bars in the precast element. The squeezing force and tension of the main steel bar can be transmitted to the grouted steel bar through the bonding force.

Please refer to FIG. 3, another aspect of the present invention is to provide a plurality of steel bars 8 to be cast on the end of the first concrete element. The end of the reinforcing bar 8 is provided with threads for connecting to a mechanical joint 9. The mechanical joint 9 has an open and exposed end for connecting another threaded steel bar. A group of shaped spaces 10 is formed at one end of the second concrete element, and at least one concrete element is prefabricated. The shaped space 10 can be formed by traditional methods such as metal bellows, hole models, or new methods as described below. The shaped space is formed beside the main steel bar 11 close to the concrete element.

Place the first concrete element in a predetermined position in advance. The mechanical joint is cast in the first concrete element. Those skilled in the art of the present invention know that it can also be cast in the second concrete element. If one of the components is cast-in-situ rebar, it is placed first. The setting of the position of the shaped space 10 is used to set the concrete element to the position where the connector 9 is provided when the ends of the two concrete elements are connected.

Before positioning the second preform, the connecting steel bar 12 is inserted into the shaped space 10 of the concrete element. The connecting steel bar 12 is held and positioned by a lead wire fastened to its end. The connecting steel bars 12 are arranged equidistantly along the length of the steel bars through one or more centering devices to maintain the steel bars in the center of the shaped space.

The second prefabricated element is properly placed so that it has a shape space to align with the mechanical joint and maintain a gap 13 of approximately 20 mm between the ends of the two concrete elements. Push one end of the steel bar from a small hole (conduit) 14 through a bendable rod or device, and then push the temporarily held steel bar to a 20 mm gap to the connector of the touch mechanism. The small hole 14 is used for prefabricated components. Holes set for grouting operations. The size of a wrench is designed to be able to penetrate into the gap 13 to rotate the connecting steel bar 12 provided with threads to rotate into the mechanical joint. The length of the connecting steel bars 12 is set so that when it is completely locked into the mechanical joint, it has a lap length sufficient to overlap the main steel bars 11.

Finally, non-shrinking cement is poured to fill the connected shaped space 10 and the gap 13 between the two prefabricated elements. The connecting steel bar 12 and the main steel bar 11 form an effective overlap in the concrete element, and the extrusion force and tension of the main steel bar 11 of the first concrete element can be transmitted to the connecting steel bar 12 through the bonding force. The internal force can also be transmitted to the second concrete element main steel bar 11 and other concrete elements through mechanical joints. The structural connection of the two elements is completed as described above.

The new method proposed by the present invention has the following advantages:

1. It can avoid the problem that the steel bar extends outside the prefabricated element. It will be more efficient in transportation and reduce costs.

2. Compared with inserting a long steel bar into the hole of the conduit, the new method is relatively simpler only when there is a shape space on the spot.

3. With current technology, it is difficult to connect inclined prefabricated structural elements, because it is very difficult to lift heavy prefabricated elements so that a long steel bar can be inserted into the duct at an angle. The connection method of the present invention can solve such problems and can be applied to beams, columns, plates and inclined components.

4. By using the present invention, the construction of the entire building can be completed by connecting basic structural elements such as columns, walls, diagonal braces, beams and plates.

5. The connection of prefabricated elements only has a gap of about 20 mm for construction error, and the site does not need to use any formwork or pour concrete.

6. There is no need for on-site modeling, steel tying or concrete pouring, only the connection of prefabricated elements is required, which speeds up construction time and greatly reduces on-site construction personnel.

7. All steel tying can be done in the factory, which can reduce material loss and greatly reduce the carbon footprint caused by transportation.

8. The completed building is assembled by prefabricated elements, and there are only cement mortar joints between the prefabricated elements. Therefore, the facing bricks, fair-faced concrete and colored concrete can be completed in the factory, and only the connection work needs to be completed on the construction site.

As shown in Figures 4 and 5, the method for forming the shaped space provided by the corresponding steel bar is described as follows. As shown in Figure 4. A pin/rod as an internal former 1 can be a steel bar, a cylinder, or a round steel pipe; other shapes can be achieved by combining multiple steel bars and round steel pipes. The internal former is provided with a layer of grease or oil. A polymeric anti-adhesive layer wraps in a roughly spiral pattern from an inner end to an outer end of the inner former 1 as an anti-adhesive wrapper. The material can be plastic, veltron or silicone strip. (silicone strip) 2. Another way is to use a steel cable as a strip to wind the inner former 1, and a plurality of strips can be stacked to form a hole with a random cross-sectional shape. The surrounding former is placed in a mold and poured into the precast concrete element 3. When the cement is hardened, the internal former 1 is drawn out from the pre-injection element. Since the friction force between the lubricated inner former and the wrapper is much smaller than the friction between the surrounding member and the concrete, the inner former 1 can be easily pulled out, and the polymer release layer is left behind. Among the concrete. The polymer release layer can be made by extrusion, and its shape and contour can be designed as ribs or other structures that can further reduce friction (as shown in Figure 5). The contact between the profile of the strip and the concrete is designed to promote the subsequent transfer of the bonding force between the steel and concrete.

After the internal former is removed, the strip of the surrounding member exposed at the end of the opening can be drawn out of its own shape space. Since the surrounding member is spirally wound, the strip can be gradually peeled off from the inner surface of the concrete element. Holes 6 The contours are formed in precast concrete elements. The contour design of the strip can be specially made into ribs or grooves and formed on the inner wall of the hole, thereby strengthening the force transmission between the embedded steel bar and the main body of the prefabricated element. If the steel cable is used as the surrounding layer, a rib will be formed on the inner wall of the hole, which will also strengthen the friction and force transmission. The hole formed by this method has the same effect as the traditional corrugated pipe, and has the following advantages:

1. Use multiple internal formers to form larger holes to place multiple steel bars in the larger holes for the connection of prefabricated elements.

2. Unlike round shapes, other shapes such as squares and rectangles can be formed by this method to conform to the structural design.

3. The internal former, polymer release layer or cable can all be reused.

4. This method forms holes in the precast concrete, which is a more economical and flexible method of design.

The connection technology of the present invention uses grouting to fill the holes and install the steel bars in them. The purpose of grouting the hole-filled conduit is to ensure that the internal force can be effectively transmitted between the steel bar and the concrete. The conventional method is to send the slurry hydraulic pressure into one end of the hole duct, and then overflow the duct at the other end, and then seal both ends of the inlet and outlet. When the two ends of the hole duct are at different levels, the slurry inlet is placed at a lower position, so that the rising slurry removes the air in the hole duct until the slurry overflows from the outlet.

When there are multiple conduit holes to be grouted, one end is connected to a gap, such as a standard column preform connection, the grout is sent from the bottom gap, and then rises in each conduit hole to the exit at the top of the conduit hole Gush.

The disadvantages of this system are:

1. Overflowing slurry causes waste of materials. In some cases, the slurry at multiple outlets will cause more waste if it is not sealed in time.

2. The solidification of the overflow slurry requires manual removal and cleaning, which is very labor intensive, especially if the site is not properly managed, resulting in a large-scale overflow slurry.

3. After the grouting is completed, the grouting pipeline extending from the outlet needs to be cut off.

4. There must be someone on site to monitor the exit of the duct hole and seal the exit in time when the slurry overflows, which is impossible in some situations.

As shown in Figures 6 and 7, a grouting monitoring element can be installed at the outlet of the hole duct to reduce the waste of materials caused by the overflow of grout and avoid the cleaning of the overflow. As shown in Fig. 7, a plastic or metal shell 1 is connected to a hole conduit 2 to monitor the slurry. Generally speaking, the monitoring location will be far away from the entrance of the grouting (inlet 6 in Fig. 6), or placed along the path of the grouting or at the other end of the hole duct. As shown in FIG. 7, a plastic plate body 3 covers the plastic shell 1 and is provided with a plurality of small holes 4. The size of the small hole 4 is designed to allow air to pass through but the slurry cannot circulate. One or more channels 5 for the slurry to flow are provided on the back of the plastic plate 3. The width of the channel 5 becomes narrower as it approaches the plastic plate 3, and the grouting monitoring element can be made of a transparent plastic, so as to clearly monitor the slurry flowing into the grouting monitoring element. The grouting monitoring component can be cast in the prefabricated component in the factory, or installed by drilling and connecting the hole pipe before grouting. The plastic plate should be set on the surface of the precast concrete and can be seen, and the open end of the grouting monitoring element should be connected to the pipe of the hole to be grouted.

During the grouting operation, the grout gradually fills the hole duct and pushes air to the grouting monitoring element. Through the above-mentioned design, the air can be discharged out of the grouting monitoring element through the narrower channels and small holes of the disc body. When the grout fills the hole duct to the position of the grout monitoring element, the grout will be introduced into the channel 5 of the grout monitoring element. The narrower channel 5 will hinder the flow of the grout and reduce the head of the grout, and finally be blocked by the small hole 4 of the plate 3 (A small amount of slurry water will flow out). The blocked slurry will stay behind the plate 3, and the transparent plate 3 can be used for observation to show whether the slurry is full.

As shown in Figure 6, it illustrates an example of precast straight column grouting. A plurality of hole ducts and steel bars are connected in the base of the straight column. The grouting operation is expected to push the grout from the base through an inlet 6 and the grout will move up to the top of the duct along the hole. The grouting monitoring element 7 is arranged at the top position of the hole duct. The transparent disk of the grouting monitoring element 7 displays the state of grout filling. When the transparent disk is filled with grout, the grouting is stopped.

The advantages of using grouting monitoring components are:

1. Can reduce or avoid the waste of slurry.

2. There is no need to install manpower at the grouting outlet and remove wasted grout, thereby saving manpower.

3. There is no overflow slurry, and the prefabricated component can be the final product.

4. The surface of the plastic plate and the precast concrete are arranged on a plane, and the plate can be covered by painting.

5. Place the grouting monitoring element in a suitable place, which can be used to monitor and verify the complex grouting operation of multi-path grouting.

The present disclosure is not limited to the specific systems, devices, and methods described, as these can vary. The terminology used in the specification is only for the purpose of describing a specific statement or implementation, and is not intended to limit the scope.

In the above detailed description, reference is made to the accompanying drawings, which form a part of this document. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrated embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be used and other changes may be made without departing from the spirit or scope of the subject matter presented herein. It will be readily understood that, as generally described herein and illustrated in the drawings, aspects of the present disclosure can be arranged, substituted, combined, divided, and designed in a wide variety of different configurations, all of which are described herein. Think clearly.

The present disclosure according to the specific embodiments described in this application will not be limited, and it is intended as an illustration of various aspects. As will be clear to those skilled in the art, many modifications and changes can be made without departing from the spirit and scope of the present disclosure. Within the scope of the present disclosure, functionally equivalent methods and devices, except those listed herein, will be clear to those skilled in the art from the foregoing description. Such modifications and changes are intended to fall within the scope of the attached claims. The present disclosure will only be limited by the terms of the appended claims and the full scope of the equivalents of the rights given by such claims. It will be understood that the present disclosure is not limited to specific methods, reagents, compounds, compositions, or biological systems, which can of course vary. It will also be understood that the terms used herein are only for the purpose of describing specific embodiments and are not intended to be limiting.

The various above-disclosed and other features and functions, or alternatives thereof, can be incorporated into many other different systems or applications. Those skilled in the art can subsequently make various substitutions, modifications, alterations, or improvements therein that are currently unforeseen or unpredictable, each of which is also intended to be covered by the disclosed embodiments.

Claims

A method for forming overlapping connections between concrete structures, including:

A first shaped space is formed in the first concrete structure, and the first shaped space is arranged beside the first main steel bars of a first concrete structure;

Placing a movable steel bar in the first shaped space, the length of the movable steel bar is shorter than the length of the first shaped space, so that the movable steel bar is completely contained in the first shaped space;

A second concrete structure is placed next to the first concrete structure. The second concrete structure includes a second shaped space adjacent to a second main steel bar in the second concrete structure. The position where the second shaped space is set is approximately coaxial with the first shaped space of the first concrete structure; or a mechanical joint replaces the second shaped space, facing the first concrete structure The first shaped space;

Move the movable steel bar to a position where a part of the movable steel bar is located in the first shaped space and a part is located in the second shaped space, so that the movable steel bar and The first main reinforcing bar and the second main reinforcing bar partially overlap; and

The grout fills the first shaped space and the second shaped space.
The method for forming an overlap connection between concrete structures according to claim 1, wherein the method further comprises placing a central element on the movable steel bar for the The moving steel bar is placed in the first shaped space.
The method for forming an overlap connection between concrete structures according to claim 2, wherein the neutral element is a metal spring coil.
The method for forming an overlap connection between concrete structures according to claim 1, wherein the method further comprises using a wire to hold the movable steel bar in the first shaped space Inside.
The method for forming an overlap connection between concrete structures according to claim 1, wherein the method further comprises using a device disposed between the first shaped space and the first concrete structure. Hole conduit between the sides to receive grout.
The method for forming lap joints between concrete structures according to claim 5, wherein the method further comprises using a lead wire, one end of the lead wire passing through the hole conduit for holding the The movable steel bar is in the first shaped space.
The method for forming lap joints between concrete structures according to claim 1, wherein when the second shaped space of the second concrete structure is replaced by the mechanical joint, The movable steel bar and the mechanical joint have threads respectively, and the steel bar is screwed into the mechanical joint by moving and rotating the steel bar.
The method for forming an overlap connection between concrete structures according to claim 5, wherein the overlap connection further comprises a second hole conduit, which is arranged in the second modeling space and the first Two between one side of the concrete structure.
A grouting monitoring element used in the grouting of concrete structures, including:

A shell connected to a hole duct;

A plate body, which covers the shell and is provided with a plurality of small holes, and is provided with one or more grouting channels for the flow of grout on the back,

Wherein, the size of the small hole is designed to allow air to pass but the slurry cannot circulate.
9. The grouting monitoring element according to claim 9, characterized in that the grouting monitoring element is placed on the grouting exit hole and the key path of grouting to observe the progress of grouting.
9. The grouting monitoring element according to claim 9, characterized in that the grouting monitoring element further comprises a display of completion of grouting to prevent overflow of grout.
9. The grouting monitoring element according to claim 9, wherein the width of the plurality of grouting channels narrows as they approach the monitoring surface; in addition, the surface of the grouting monitoring element is transparent.
9. The grouting monitoring element according to claim 9, wherein the housing is made of plastic or metal.
9. The grouting monitoring element according to claim 9, wherein the disc body is made of plastic.
A method for forming a duct with a shape space or a hole applied to a concrete structure includes:

One or more round rods, square rods, or other shaped rods are combined to form an internal former;

Wrap the inner former in a roughly spiral pattern with a release layer;

Pull out the internal former after pouring the concrete;

Finally, the anti-adhesion layer is pulled out to form a shaped space or hole conduit in the concrete structure.
The method according to claim 15, wherein the material of the anti-adhesive surrounding layer is plastic, Feriron or silicone strip or steel cable.