Precast members, connection sleeves, systems and methods for joining precast members

Abstract

The present invention relates to a system and method for joining at least two precast members, including a precast member, sleeve, system, and method. The system includes a connecting sleeve (10, 20) for placement on a first precast member (100). The connecting sleeve (10, 20) has a rebar (30) movably positioned within the connecting sleeve (10) or a cover cap (60) slidably positioned within the connecting sleeve (20). The present invention provides an effective and optimized configuration with products and systems for joining precast members that ensures a strong connection between the precast members while ensuring a uniformly strong bond and restraint throughout the length of the rebar, including any gaps between the precast members.

Description

Detailed Description of the Invention

[0001] [Technical Field] This application is a family application claiming priority to three applications, patent application nos. 202221053066, filed September 16, 2022; 202321033696, filed May 12, 2023; and 202321052559, filed August 4, 2023, which are hereby incorporated into one complete specification. FIELD OF THE INVENTION The present invention relates to systems and methods for joining precast members, and more particularly to precast members, sleeves, systems and methods. 〔background〕

[0002] Precast construction is a construction method in which precast, pre-constructed, and pre-assembled components, such as walls, columns, beams, slabs, 3D modules, and pillars, are assembled and joined on-site instead of being constructed individually. A key aspect of this construction method is the strong and accurate joining of these precast components on-site. Current technology, such as patent publications WO2017187451 and WO2019186600, discloses systems and methods for joining precast components, in which two precast components with hollow sleeves positioned adjacent to each other are joined together, and rebar is transferred from one component to the other through the hollow sleeve. The next step involves mixing a wet grout mix and injecting / pumping it on-site to insert it into the sleeve and fill any gaps between the precast and rebar-inserted components. However, because the alignment of the precast components, the insertion of the rebar, and the grouting of the sleeve to complete the construction are critical structural tasks, careful attention must be paid to filling and constructing the hollow sleeve to ensure it is fully filled with grout. Furthermore, it has been determined that even if the entire surface of the reinforcing bars is covered with grout, grout bonded over the portion of the reinforcing bars in gaps between precast members may fail in adverse conditions such as earthquakes where the walls are cyclically loaded with a combination of shear and bending loads, unless there is additional restraint around the reinforcing bars in the gaps.

[0003] Therefore, there is a need for an effective and optimized configuration of products and systems for joining precast members that ensures a strong connection between the precast members while ensuring a uniformly strong bond and restraint throughout the entire length of the rebar, including the gaps between the precast members.

[0004] In one aspect, the present invention provides a system for joining at least two precast members, the system comprising: a first connection sleeve for placement within a first precast member; the first connection sleeve having a reinforcing bar movably disposed therein; the reinforcing bar being movable from the first connection sleeve to a second connection sleeve for joining the first precast member to the second member; a second connection sleeve for placement within a second precast member; the second connection sleeve having a hollow cylindrical cover cap with a collar at a first end and at least one through hole formed in a body slidably disposed within the second connection sleeve; the cover cap having a length greater than the distance between the first and second precast members to cover a portion of the reinforcing bar between the gaps between the two precast members to form a strong and uniform joint throughout the entire length of the reinforcing bar, including the gaps between the precast members; Each connecting sleeve includes an aligner plate attached to a first end of the first connecting sleeve and the second connecting sleeve; at least one engaging link that secures the connecting sleeve and transmits tensile, bending, and shear stresses of the connecting sleeve to the inner frame of the precast member by engaging the first connecting sleeve and the second connecting sleeve with the inner frame; and a sensing indicator removably connected to each connecting sleeve configured with the precast member to indicate completion of the grouting process in the connecting sleeve after transferring the rebar from the first connecting sleeve to the second connecting sleeve. The sensing indicator is a hollow member having an opening. The hollow body includes a ball having a diameter larger than the diameter of the opening. Each connecting sleeve includes at least one support plate that penetrates the connecting sleeve. The support plate has at least one holder, and an engaging link penetrates the holder of the support plate to engage the connecting sleeve with the inner frame.

[0005] In another aspect, the present invention provides a connecting sleeve including an aligner plate attached to a first end of the connecting sleeve. A sensing indicator is removably connected to a surface of the connecting sleeve at a second end thereof and functions as a built-in shutter system to indicate completion of the grout replenishment process within the connecting sleeve. The connecting sleeve includes a rebar movably disposed within the connecting sleeve, or a hollow cylindrical body having a collar at one end, a cover cap having at least one through-hole formed in a body portion, and a cover cap slidably disposed within the connecting sleeve.

[0006] The present invention provides a precast element comprising a plurality of first connecting sleeves and / or a plurality of second connecting sleeves arranged in a predetermined manner.

[0007] The present invention provides a method for manufacturing a precast member, which includes the steps of preparing an inner frame (50) by fixing vertical and horizontal bars to a mold plate of the precast member, marking a center point for placing at least one first connecting sleeve and / or at least one second connecting sleeve on the mold plate, installing the connecting sleeve at a predefined position in the inner frame, fixing the connecting sleeve to the inner frame, fixing a plug to the mold plate by nuts, bolts, magnets, or welding, placing the first connecting sleeve, which has been pre-fixed by the aligner plate, on the precast member, and fixing the precast member to the inner frame. the steps of: installing a tube in an access hole of the first connection sleeve to access the rebar from the outer surface of the precast member; installing another tube at the second end of the connection sleeve to connect a sensing indicator; applying duct tape to various joints to prevent leakage of cement slurry into the connection sleeve; closing the ends of the first and second connection sleeves with aligner plates to keep the tube outlets outside the surface of the inner frame; pouring concrete into the mold to cast the precast member (100, 200); and allowing the mold to harden until the concrete gains strength. In another embodiment, the step of fixing the connection sleeve to the inner frame includes the steps of: placing at least one support plate through the connection sleeve; and fixing the connection sleeve to the inner frame by passing the engagement link through the support plate and a holder of the inner frame.

[0008] In another aspect, the present invention provides a method for joining at least two precast members. In a first step, a first precast member having a first connecting sleeve and a second precast member having a second connecting sleeve are positioned opposite each other with a gap between them so that the aligner plates of the first connecting sleeve and the second connecting sleeve are aligned with each other. In a second step, a reinforcing bar disposed in the first connecting sleeve is moved to a predetermined position within the second connecting sleeve. In a next step, a cover cap disposed in the second connecting sleeve is moved from the second connecting sleeve toward the first connecting sleeve so that the collar of the cover cap contacts the side of the precast member adjacent to the aligner plate of the first connecting sleeve. In a next step, a grout mixture is introduced into the gap from above the members in the gap until a sensor indicator indicates completion of the grout filling process into the hollow space between the connecting sleeve, the reinforcing bar, and the cover cap. In the final step, the grout is filled into the first and second connecting sleeves, the hollow space between the reinforcing bar and the cover cap, and the gap, forming a strong bond between the reinforcing bar, the sleeves, and the cover cap, thereby joining the precast members together. [Brief description of the accompanying drawings]

[0009] The detailed description will now be made with reference to the accompanying drawings, in which like numbers are used to refer to features and modules throughout.

[0010] FIG. 1 shows a cross-sectional view of a system for joining precast components with a connection sleeve according to one embodiment of the present invention. 2A and 2B show perspective and front views of the first connecting sleeve of FIG. 1 positioned within a precast member of a system according to an embodiment of the invention. 3A and 3B show perspective and front views of the second connecting sleeve of FIG. 1 positioned within a precast member of a system according to an embodiment of the present invention. FIG. 4 shows a perspective view illustrating the joined connection sleeves of the system of FIG. 1 in accordance with an embodiment of the present invention. FIG. 5A shows an exploded view of the first connecting sleeve of the system of FIGS. 2A and 2B in accordance with an embodiment of the present invention. FIG. 5B shows an exploded view of the second connecting sleeve of the system of FIGS. 3A and 3B, according to an embodiment of the present invention. FIG. 6 shows a front view of a grout sensing indicator of a system according to an embodiment of the present invention. 7A and 7B show perspective and front views of a second connecting sleeve of a system according to another embodiment of the present invention. 8A and 8B show a photograph and a front view of the precast members during the joining process.

[0011] Those skilled in the art will appreciate that any block diagrams herein are intended to represent conceptual views of illustrative systems embodying the principles of the present disclosure. Detailed Description of the Invention

[0012] In the following description, for purposes of explanation, specific details are set forth in order to provide an understanding of the present disclosure. However, it will be apparent to one skilled in the art that the present disclosure may be practiced without these details.

[0013] Those skilled in the art will recognize that various embodiments of the present disclosure, some of which are described below, can be incorporated into many systems.

[0014] However, the present systems and methods are not limited to the particular implementations described herein. Moreover, the structures and devices shown in the figures are illustrative of exemplary implementations of the present disclosure and are intended to avoid obscuring the disclosure.

[0015] Additionally, connections between components and / or modules in the figures are not intended to be limited to direct connections, but rather, these components and modules may be modified, reformatted, or otherwise altered by intermediate components and modules.

[0016] References in this disclosure to "one embodiment" or "implementation" mean that a particular feature, structure, characteristic, or function described in connection with this embodiment is included in at least one embodiment of the invention. Appearances of the phrase "in an embodiment" or "in one embodiment" in various places in this specification do not necessarily all refer to the same embodiment or implementation.

[0017] Referring to FIG. 1, a system (300) for joining precast members according to an embodiment of the present invention is shown. The precast members to be joined together include at least two precast members, namely, a first precast member (100) and a second precast member (200). The system (300) includes at least one first connecting sleeve (10) disposed at a predetermined position on the first precast member (100) and at least one second connecting sleeve (20) disposed at a predetermined position on the second precast member (200). It is understood that the number of first and second sleeves (10, 20) can vary depending on the height and dimensions of the precast members (100, 200). It is understood that, according to the present invention, when two or more precast members (100, 200) are to be joined together, the precast member disposed between the two members includes both a first and a second sleeve (10, 20) installed therein.

[0018] According to one embodiment, a first connection sleeve (10) is disposed within the first precast member (100) and a second connection sleeve (20) is disposed within the second precast member (200). A reinforcing bar (30) is movably disposed inside the first connection sleeve (10). The reinforcing bar (30) is movable from the first connection sleeve (10) to the second connection sleeve (20) to join the first precast member (100) to the second member (200).

[0019] The first and second connecting sleeves (10, 20) include aligner plates (11, 21) attached to first ends of the first and second connecting sleeves (10, 20). The connecting sleeves (10, 20) include at least one support plate or holdfast (12, 22) extending through the connecting sleeves (10, 20). The support plate (12, 22) has at least one holder (122, 222) configured thereon. The support plate (12, 22) is rotated along the helical threads of the connecting sleeves (10, 20) to a desired position.

[0020] At least one engaging link (15, 25) engages the first connecting sleeve (10) and the second connecting sleeve (20) through a holder (122, 222) of the support plate (12, 22) for engaging the connecting sleeve (10, 20) with the inner frame (50). In another embodiment, a holding frame (14, 24) is fixed to the inner frame (50) of the precast member (100, 200). The engaging link (15, 25) passes through the holder (122, 222) of the support plate (12, 22) and engages with the holding frame (14, 24). The engagement between the engaging link (15, 25) and the holding frame (14, 24) fixes the connecting sleeve (10, 20), and tensile / bending / shear stress of the connecting sleeve (10, 20) is transmitted to the inner frame (50) of the precast member (100, 200). In another embodiment, the first connecting sleeve (10) and the second connecting sleeve (20) can also be directly connected to the inner frame (50).

[0021] In accordance with another embodiment of the present invention, and referring to FIG. 6 , a sensing indicator (16) is removably connected to the second ends of the connecting sleeves (10) and (20). The sensing indicator (16) is a hollow member having an opening (160). The hollow body includes a ball (162) having a diameter larger than the diameter of the opening (160). The sensing indicator (16) indicates the completion of the grouting process within the connecting sleeve (10) after transferring the rebar (30) from the first connecting sleeve (10) to the second connecting sleeve (20) and functions as a built-in shutter system. When the grout completely fills the sensing indicator (16), the ball (162) moves toward and blocks the opening (160), thereby indicating the completion of the grouting process.

[0022] According to the present invention, the aligner plate (11) of the first connecting sleeve (10) has at least one access hole (110). The access hole (110) provides access to the rebar (30) disposed inside the first connecting sleeve (10) for transferring the rebar (30) from the first connecting sleeve (10) to the second connecting sleeve (20). The rebar (30) is transferred from the first connecting sleeve (10) to the second connecting sleeve (20) using a drive mechanism that drives the rebar (30) from one sleeve to another. The rebar (30) can also be transferred through the second sleeve (20) by pulling the same with a wire connected through the second open end of the second sleeve (20).

[0023] It should be noted that when pouring the weight of concrete onto the connecting sleeves (10, 20), the connecting sleeves (10, 20) are secured by the plugs (112, 212) removably attached to the aligner plates (11, 21), the support plates (HSR) (12, 22), and the engaging links (15, 25) or HSR bars secured to the retaining frames (14, 24) or links. The plugs (112, 212) secured to the aligner plates (11, 21) prevent the concrete slurry from entering the sleeves through any infiltration route, making the system leak-proof / waterproof. The drain holes are located higher than the top end of the sleeves.

[0024] 2A and 2B, according to the present invention, a first connecting sleeve (10) includes an aligner plate (11) attached to a first end of the first connecting sleeve (10). The aligner plate (11) has an access hole (110) for accessing the bar (30), and at least one hole is configured on the surface of the first connecting sleeve (10) at its second end. The first connecting sleeve (10) includes at least one support plate (12) passing through the first connecting sleeve (10). The support plate (12) secures the connecting sleeve (10) by facilitating engagement between at least one engaging link (15) and the inner frame (50), thereby transmitting the tensile, bending, and shear stresses of the connecting sleeve (10) to the inner frame (50) of the precast member (100). The reinforcing bar (30) is movably disposed inside the first connecting sleeve (10). The inner surface of the aligner plate (11) has a protrusion to keep the rebar (30) at a slightly elevated position while moving from the first connecting sleeve (10) to the second connecting sleeve (20).

[0025] According to the present invention, referring to Figures 3A, 3B, and 6, a second connecting sleeve (20) includes an aligner plate (21) attached to a first end and at least one hole formed in the surface of the second connecting sleeve (20) at the second end. The second end of the connecting sleeve (20) includes a sensing indicator (26) removably connected to the second end. The sensing indicator (26) is attached to the connecting sleeve (10, 20) by a separate tube attached to the end of the connecting sleeve (10, 20). The sensing indicator (26) indicates the completion of the grouting process in the connecting sleeve (20). The sensing indicator (26) is a hollow member having an opening (260). The hollow body includes a ball (262) having a diameter larger than the diameter of the opening (260). The sensing indicator (26) indicates the completion of the grouting process in the second connecting sleeve (20) after the rebar (30) has been transferred from the first connecting sleeve (10) to the second connecting sleeve (20), and functions as a built-in shutter system. A support plate (22) penetrates the second connecting sleeve (20). The support plate (22) secures the connecting sleeve (20) by facilitating the engagement between at least one engaging link (25) and the inner frame (50), thereby transmitting the tensile / bending / shear stresses of the connecting sleeve (20) to the inner frame (50) of the second precast member (200).

[0026] Referring to Figures 3A, 3B, and 7A and 7B, a system for joining two precast members (100, 200) according to another embodiment of the present invention is shown. According to this embodiment, at least one of the first and second connecting sleeves (10, 20), preferably the second sleeve, includes a cover cap (60) slidably disposed therein. The cover cap (60) has a cylindrical hollow body with a collar (61) at one end thereof and a length greater than the gap between two adjacent precast members. It should be understood that the cover cap (60) has a profile matching the profile of the second connecting sleeve (20). The cover cap (60) includes at least one through-hole (62) disposed in a predetermined position thereon. The cover cap (60) covers a portion of the reinforcing bar (30) between the gap (40) between the two precast members (100, 200). After the reinforcing bar (30) is moved from the first connecting sleeve (10) to the second connecting sleeve (20), the cover cap (60) disposed in the second connecting sleeve (20) is moved from the second connecting sleeve (20) toward the first connecting sleeve (10). When the cover cap (60) contacts the aligner plate (11) of the first connecting sleeve (10), a hollow space is formed between the reinforcing bar (30) and the inner profile of the cover cap (60), and the hollow space is filled with grout material that penetrates through the through holes (62) while filling the gap (40).

[0027] 1-8B, in another aspect, the present invention provides a method for joining two precast members. In a first step, a first precast member (100) having a first connecting sleeve (10) and a second precast member (200) having a second connecting sleeve (2) are positioned opposite each other with a gap (40) therebetween so that the aligner plate (11) of the first connecting sleeve (100) and the aligner plate (21) of the second connecting sleeve (200) are aligned with each other. In a second step, a reinforcing bar (30) positioned in the first connecting sleeve (10) is moved to a predetermined position within the second connecting sleeve (20). In a next step, a cover cap (60) is moved from the second connecting sleeve (20) toward the first connecting sleeve (10) so that the collar (61) of the cover cap (60) contacts the side of the precast member adjacent to the aligner plate (11) of the first connecting sleeve (10). In the next step, a grout mixture is introduced into the gap (40). The grout fills the bottom of the gap (40) and then moves upward against gravity, moving into the first and second connection sleeves (10, 20). During this process, the grout also penetrates through the through-holes (62) into the hollow space between the rebar (30) and the cover cap (60). In the next step, the first and second connection sleeves (10, 20), the hollow space between the rebar (30) and the cover cap (60), and the gap (40), which have now been completely filled with grout, are allowed to dry. After drying, the grout hardens and forms a strong bond with the rebar (30), the sleeves (10, 20), and the cover cap (60), thereby joining the precast components (10, 20).

[0028] The present invention provides a method for manufacturing a precast element (100, 200), which includes the steps of preparing an inner frame (50) by fixing vertical and horizontal bars to a mold plate of the precast element (100, 200), marking a center point for placing at least one first connection sleeve (10) and / or at least one second connection sleeve (20) on the mold plate, placing the connection sleeves (10, 20) at predetermined positions in the inner frame (50), fixing the connection sleeves (10, 20) to the inner frame (50), fixing plugs (112, 212) to the mold plate by nuts, bolts, magnets, or welding, placing the first and second connection sleeves (10, 20) previously fixed with aligner plates (11, 21) into the precast element, and the steps of placing a tube in the access hole (110) of the first connection sleeve (10) to access the rebar from the outer surface of the precast element (100, 200); placing another tube at the second end of the connection sleeve (10, 20) to connect a sensing indicator (16, 26); applying duct tape to various joints to prevent leakage of cement slurry into the connection sleeve (10, 20); closing the ends of the first and second connection sleeves (10, 20) with aligner plates (11, 21) to keep the outlets of the tubes outside the surface of the inner frame (50); pouring concrete into the mold to cast the precast element (100, 200); and allowing the mold to harden until the concrete has gained strength. In another embodiment, the step of fixing the connection sleeves (10, 20) to the inner structure (50) includes the steps of placing at least one support plate (12, 22) through the connection sleeves (10, 20) and passing engagement links (15, 25) through holders of the support plates (12, 22) and the inner structure (50), thereby fixing the connection sleeves (10, 20) to the inner structure (50). The distance between two consecutive connection sleeves (10, 20) depends on the structural design requirements and can be about 100 mm c / c to 750 mm.

[0029] It is understood that the rebar (30) is moved from the first connection sleeve (10) to the second connection sleeve (20) by a drive mechanism through the access hole (110) or by a wire. The rebar (30) is moved into the second connection sleeve (20) so that half of the rebar (30) remains in the first connection sleeve (10) and half of the rebar (30) remains in the second connection sleeve (20). The grout material is introduced into the gap (40) until it is discharged from at least one hole configured in the connection sleeves (10, 20) or until the sensing indicators (16, 26) attached to the second ends of the connection sleeves (10, 20) indicate complete refilling of the first connection sleeve (10) and the second connection sleeve (20).

[0030] According to one embodiment, a connection bay, when viewed in cross section (Figure 1), is the area between the inner frames (50) where a connection sleeve is planned, and can be defined as the minimum clearance distance maintained inside the connection bay. Links / ties, if present, are tied to the main bar on the outer surface of the master stirrup that defines the connection bay. In no case should the links / ties be tied inside the connection bay. Therefore, the links / ties are tied between the upper surface of the connection bay's upper master ring and the underside of the connection bay's lower master ring. The diameter of the master ring or the links / ties is not specified; this is up to the structural designer's calculation. A non-connection bay is a section of the wall between two consecutive master stirrups where no connection sleeve is planned or present. There are no regulations regarding the minimum clearance distance inside these bays, nor are there any requirements for tying links / ties to the outer surface of the master ring, etc.

[0031] According to one embodiment, the bars (15, 25) required for the holdfast and secondary reinforcement (HSR) are procured on-site by the contractor. The advantages of this in the contractor's scope are as follows: Because their length and diameter are appropriately designed, these rebars (30) can utilize "waste bars" from standard cut lengths of rebar. Wall dimensions may vary, as may other factors that determine HSR detailing, such as wall thickness, clear cover, main rebar diameter, and stirrup diameter. Because of these variables, contractors can easily issue cut-and-bend drawings for HSR bars and adapt them to the actual situation. The HSR bar design allows for precise adjustments by driving the bars to match the link and tie points. If necessary, the HSR bars can also be directly connected to the main wall bars.

[0032] Advantageously, the tip of the reinforcing bar (30) has a bullet-nose shape so that it does not interfere with the serrations of the second connecting sleeve (20), ensuring tolerance and smooth passage of the reinforcing bar (30) from the first connecting sleeve (10) to the second connecting sleeve (20).

[0033] In another embodiment, a specially designed key is inserted into the access opening / grout outlet, with one end attached to the drive mechanism and the other end attached to the drive unit. In the next step, the drive unit rotates, causing the key to rotate, and with it, the main drive wheel of the gear, again translating the connecting bar, moving it from the donor to the receptor. During this movement, the bullet-shaped nosing design smoothly moves through the inside of the receptor without any obstructions. The next step is to pass the required length of bar through the gap until a colored mark appears in the gap, indicating the completion of the stage. In the next step, a specially designed adhesive is sprayed on both sides of the wall and on the fabric / thin steel plate, evenly spaced over the entire 2-meter height of the wall. After waiting a predetermined time, the fabric / steel plate is attached to the gap and grouted. In the next step, the fabric / thin steel plate is removed, and the joint is buffed / grinded to make it appear clean. In another embodiment, the use of a sprayable adhesive with the fabric / thin steel sheeting ensures that the joints do not leak even when there is an offset between the walls, which would be very difficult for conventional shutters to adhere to, and the adhesive and fabric / thin steel sheeting are strong enough to support the load of the grout head.

[0034] The system (300) of the present invention consumes the least amount of grout within the allowable range to avoid potential mismatches. The system of the present invention requires the fewest number of holes in the finished wall. The system can be used for both horizontal and vertical castings due to the rotatable grout outlet and T-shaped emergency access hole, allowing for a left-right compatible design. The system can accommodate wall thicknesses from 150mm to 400mm or even more.

[0035] The foregoing description of the present invention has been set forth merely to illustrate the present invention and is not intended to limit the present invention. Since modifications of the disclosed embodiments that incorporate the spirit and substance of the present invention may occur to those skilled in the art, the present invention should be construed as including all within the scope of the present disclosure. [Brief explanation of the drawings]

[0036] [Figure 1] 1 shows a cross-sectional view of a system for joining precast members with a connection sleeve according to one embodiment of the present invention. [Figure 2A] 2 shows a perspective view of the first connecting sleeve of FIG. 1 positioned within a precast member of a system according to an embodiment of the present invention. [Figure 2B] 2 shows a front view of the first connecting sleeve of FIG. 1 positioned within a precast member of a system according to an embodiment of the present invention. [Figure 3A] 2 shows a perspective view of the second connecting sleeve of FIG. 1 positioned within a precast member of a system according to an embodiment of the present invention. [Figure 3B] 2 shows a front view of the second connecting sleeve of FIG. 1 positioned within a precast member of a system according to an embodiment of the present invention. [Figure 4] 2 shows a perspective view illustrating joined connection sleeves of the system of FIG. 1 according to an embodiment of the present invention. [Figure 5A] 2C shows an exploded view of a first connecting sleeve of the system of FIGS. 2A and 2B in accordance with an embodiment of the present invention. [Figure 5B] 3C shows an exploded view of a second connecting sleeve of the system of FIGS. 3A and 3B in accordance with an embodiment of the present invention. [Figure 6] FIG. 1 illustrates a front view of a grout sensing indicator of a system according to an embodiment of the present invention. [Figure 7A] 10 shows a perspective view of a second connecting sleeve of a system according to another embodiment of the present invention. [Figure 7B] 10 shows a front view of a second connecting sleeve of a system according to another embodiment of the present invention. [Figure 8A] Photographs showing the process of joining precast members are shown. [Figure 8B] 1 shows a front view of the precast members during the joining method.

Claims

1. 1. A system for joining at least two precast members, comprising: a first connection sleeve (10) for placement within a first precast member (100), the first connection sleeve (10) having a reinforcing bar (30) movably positioned within the first connection sleeve (10); a second connecting sleeve (20) disposed within the second precast member (200), the second connecting sleeve (20) having a hollow cylindrical cover cap (60) slidably disposed within the second connecting sleeve (20) and having a collar (61) at a first end thereof; and wherein the cover cap (60) has a length greater than the distance between the first and second precast members (100, 200) to cover a portion of the reinforcing bar (30) between the gaps between the two precast members (100, 200) when the reinforcing bar (30) is moved from the first connecting sleeve (10) to the second connecting sleeve (20) to join the first precast member (100) to the second precast member (200) forming a strong and uniform bond along the entire length of the reinforcing bar (30), including the gaps between the two precast members (100, 200).

2. Each connecting sleeve (10, 20) an aligner plate (11, 21) attached to a first end of the first connecting sleeve and the second connecting sleeve (10, 20); at least one engaging link (15, 25) that engages the first and second connecting sleeves (10, 20) with the inner frame (50), thereby fixing the connecting sleeves (10, 20) and transmitting tensile / bending / shear stresses of the connecting sleeves (10, 20) to the inner frame (50) of the precast member (100, 200); 2. The system of claim 1, further comprising: a sensing indicator (16, 26) removably connected on each connection sleeve (10, 20) configured with the precast members (100, 200) for indicating completion of a grouting process in the connection sleeve (10, 20) after transferring the reinforcing bar (30) from the first connection sleeve (10) to the second connection sleeve (20).

3. The cover cap (60) forms a hollow space between a part of the reinforcing bar (30) between the two precast members (100, 200) and an inner part of the cover cap (60); The system of claim 1 , wherein through holes (62) are configured in the body of the cover cap (60) for refilling the grout into the hollow space to form a joint.

4. the sensing indicator (16, 26) is a hollow member having an opening (160, 260); The system of claim 2 , wherein the hollow body includes a ball (162, 262) having a diameter greater than a diameter of the opening (160, 260).

5. Each connecting sleeve (10, 20) includes at least one support plate (12, 22) passing through said connecting sleeve (10, 20); The support plate (12, 22) has at least one holder (122, 222) configured on the support plate (12, 22), 3. The system according to claim 1 or 2, wherein an engaging link (15, 25) passes through the holder (122, 222) of the support plate (12, 22) to engage the connecting sleeve (10, 20) with the inner frame (50).

6. an aligner plate (11, 21) attached to a first end of the connecting sleeve (10, 20); a sensing indicator (16, 26) removably connected to the surface of the connecting sleeve (10, 20) at the second end and functioning as a built-in shutter system to indicate completion of the grout refilling process within the connecting sleeve (10, 20).

7. The connection sleeve (10, 20) of claim 6, wherein the connection sleeve comprises a reinforcing bar (30) movably arranged inside the connection sleeve (10), or a hollow cylindrical body having a collar (61) at one end, at least one through hole (62) formed in the main body portion, and a cover cap (60) slidably arranged within the connection sleeve (20).

8. A precast element (100, 200) comprising a plurality of first connection sleeves (10) and / or a plurality of second connection sleeves (20) arranged in a predetermined manner.

9. A method for manufacturing a precast element (100, 200), comprising the steps of: preparing an internal structure (50) by fixing vertical and horizontal bars to the mold plates of said precast elements (100, 200); marking a center point for placing at least one first connecting sleeve (10) and / or at least one second connecting sleeve (20) on said mold plate; Fixing the plug (112; 212) to the mold plate by nuts, bolts, magnets or welding; placing the first and second connecting sleeves (10, 20), which have been previously fixed with aligner plates (11, 21), in the precast members (100, 200); placing a tube in the access hole (110) of the first connection sleeve (10) to access the reinforcing bar (30) from the outer surface of the precast element (100); placing another tube at the second end of the connecting sleeve (10, 20) for connecting a sensing indicator (16, 26); applying duct tape to various joints to prevent leakage of cement slurry into the connecting sleeve (10, 20); pouring concrete into the mold to cast the precast member (100, 200); and allowing the mold to harden until the concrete has gained strength.

10. The step of fixing the connecting sleeve (10, 20) to the internal structure (50) comprises: placing at least one support plate (12, 22) through said connecting sleeve (10, 20); and fastening the connecting sleeve (10, 20) to the internal structure (50) by passing the engaging link (15, 25) through the support plate (12, 22) and a holder of the internal structure (50).

11. A method for joining at least two precast members (100, 200), comprising the steps of: A process of placing a first precast member (100) having a first connecting sleeve (10) so that the aligner plate (11) of the first connecting sleeve (100) and the aligner plate (21) of the second connecting sleeve (200) are aligned with each other, and placing a second precast member (200) having a second connecting sleeve (20) facing each other with a gap (40) between them and the first precast member (100); a step of moving the reinforcing bar (30) disposed in the first connection sleeve (10) into the second connection sleeve (20) to a predetermined position within the second connection sleeve (20); moving the cover cap (60) disposed in the second connecting sleeve (20) from the second connecting sleeve (20) toward the first connecting sleeve (10) so that the collar (61) of the cover cap (60) contacts the side of the precast member adjacent to the aligner plate (11) of the first connecting sleeve (10); sealing the gaps between the components with a suitable grout / sealant; introducing a grout mixture into the gap (40) from above the member in the gap (40) until a sensing indicator (16, 26) indicates completion of the grouting process; drying and hardening the grout filled into the first and second connection sleeves (10, 20), the hollow space between the reinforcing bar (30) and the cover cap (60), and the gap (40); and joining the precast members (10, 20) by forming a strong bond between the reinforcing bar (30), the sleeves (10, 20), and the cover cap (60).

12. 12. The method of claim 11, wherein the rebar (30) is moved from the first connecting sleeve (10) to the second connecting sleeve (20) by inserting the drill bit through an access hole (110) or a wire rope / string, one end of which is attached to the center of the rebar (30) and the other end of which is accessible through the gap (40).

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