JP2008190175A - Joining method and joint structure of precast reinforced concrete beam members - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a joining method and a joint structure of precast reinforced concrete beam members shortening a construction period and excelling in workability, safety and economical efficiency. <P>SOLUTION: The mutual joint ends of the beam members 10, 11 are provided with cutout parts 10a, 11a formed by cutting out the width of the beam members in stepped shape to coincide with each other when brought close to a nearly abutting state. Beam main reinforcements 1 arranged in the beam members are exposed into the cutouts, and the tip parts of the exposed beam main reinforcements are formed in lump shape 1a. The beam members are positioned in mutually facing arrangement. In a rectangular space formed by the beam main reinforcements exposed to the cutout parts of the beam members, a connecting member 12 formed by combining reinforcements 2 having lumps 2a at both ends, in X-shape are positioned within the mutual cutout parts of the beam members, and stirrups 3 are arranged at the exposed beam main reinforcements. A hardening material is then filled in the mutual cutout parts of the beam members to integrally join the precast reinforced concrete beam members to each other. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention belongs to a technical field of a joining method and a joining structure of precast reinforced concrete (hereinafter sometimes abbreviated as PCa) beam members.

  Conventionally, as illustrated in FIGS. 6A and 6B, the joining method and the joining structure between the PCa beam members are obtained by joining the reinforcing bars b and b protruding from the opposing PCa beam members a and a to each other, Generally, post-construction work (not shown) such as post-cast concrete placement work is performed. Incidentally, as a method of joining (joining) the reinforcing bars b and b, a pressure welding joint method, a weld joint method, a mechanical joint method, and the like are carried out. In order to reliably perform the work of joining the reinforcing bars b and b, from the viewpoint of workability, it is common to perform the joining work while securing an interval L between the PCa beam members a and a of about 150 cm ( For example, see FIG. 1 of Patent Document 1, FIG. 4 of Patent Document 2, and FIG. 3 of Patent Document 3. Incidentally, FIGS. 6A and 6B show an embodiment constructed in a structural form (so-called skewering method or the like) in which a plurality of column main bars c are projected above the PCa column member e. The symbol d in the figure indicates a support work.

  However, since the conventional method of joining the PCa beam members a and a needs to secure a distance of about 150 cm between the PCa beam members a and a, after the joint work between the reinforcing bars b and b is finished, In order to fill the gap between the members a and a, a concrete casting mold is installed in the vicinity of the joint between the opposing PCa beam members a and a, and the concrete is cast to connect the reinforcing bars b and b. It was necessary to perform a large-scale post-work for integrating the portion and the PCa beam members a and a. Therefore, there was a problem that the construction period was prolonged and it was too uneconomical.

  By the way, FIG. 7 has shown the joining method from which PCa beam members a and a differ. In this joining method, a sleeve joint f is embedded horizontally in one (left side in the illustrated example) PCa beam member a, and a reinforcing bar b is projected horizontally in the other (right side in the illustrated example) PCa beam member a. The other PCa beam member a is moved in the horizontal direction (left direction in the illustrated example), the rebar b is inserted into the sleeve joint f, and the grout is filled in the joint portion. The beam members a and a are joined to each other (for example, see FIG. 3 of Patent Document 4).

  According to the joining method according to FIG. 7, the PCa beam members a and a can be joined to each other by an operation of filling the joint part with grout without leaving almost any gap between the PCa beam members a and a. Therefore, a large-scale post-work such as placing concrete formwork in the vicinity of the joint portion between the PCa beam members a and a facing each other and placing concrete is unnecessary, and can be greatly simplified. Compared with the joining method according to FIGS. 6A and 6B, the post-construction can be simplified to shorten the construction period, and it seems to be excellent in economic efficiency.

JP-A-3-212537 JP-A-5-340003 JP-A-5-86643 Japanese Patent Application Laid-Open No. 2004-346587

  Although the joining method according to FIG. 7 (for example, Patent Document 4) can simplify the post-construction and shorten the construction period as compared with FIGS. 6A and 6B, This is because it is carried out in a structural form (so-called reverse skewering method, reverse insertion column, etc.) in which a plurality of column main bars c are projected below the PCa column member e, which allows horizontal movement of the column.

That is, as shown in FIGS. 6A and 6B, the horizontal movement of the PCa beam member a is constrained for the structure type in which a plurality of column main bars c protrude above the PCa column member e. Such a joining method, that is, a joining method in which the PCa beam member is moved in the horizontal direction cannot be applied at all, and it is still necessary to carry out a large-scale post-work, and the problem that the construction period is prolonged and too uneconomical cannot be solved. .
Further, in the joining method according to FIG. 7, it is necessary to move the PCa beam member a having a weight of several tons in the horizontal direction, and the PCa beam member a is lowered until the upper PCa column member e is attached. The PCa pillar member e is forced to be in an unstable state that is merely placed on the upper surface of the PCa column member e, which is problematic in terms of safety. Further, in the joining method according to FIG. 7, the left PCa beam member a in the drawing is first positioned, and then the right PCa beam member a is positioned. The PCa beam member “a” cannot be positioned and is greatly restricted by the construction procedure, which contributes to a longer construction period.

  The object of the present invention is not only the structural form (see FIG. 7) in which a plurality of column main bars c protrudes below the PCa column member e, but also the structural form in which a plurality of column main bars c protrudes above the PCa column member e. (Refer to FIGS. 6A and B) It can be particularly preferably implemented, and it is not necessary to move the PCa beam member a in the horizontal direction when joining the PCa beam members a and a, and simplifies the large-scale post-work. An object of the present invention is to provide a joining method and a joining structure between precast reinforced concrete beam members, which can shorten the construction period and are excellent in workability, safety, and economy.

As a means for solving the above-mentioned background art, the method for joining the precast reinforced concrete beam members according to the invention described in claim 1 is substantially close to the contact state between the joint ends of the beam members. A notch part in which the width and thickness of the beam member are notched in steps is provided so as to coincide with each other, and the beam main bar arranged in the beam member is exposed into the notch part, and the tip of the exposed beam main bar is exposed. Forming in a hump shape, positioning the beam members close to each other in a substantially abutting state,
In the rectangular space formed by the main beam of the beam exposed at the notch of the beam member, a connecting member formed by combining reinforcing bars with knots at both ends in an X shape is provided in the notch of the beam members. Are positioned so as to extend almost evenly, and the stirrups are arranged in the exposed beam main bars, and then the notched portions of the beam members are filled with a hardening material so that the precast reinforced concrete beam members are integrated with each other. It is characterized by joining.

  According to a second aspect of the present invention, in the method for joining precast reinforced concrete beam members according to the first aspect, the beam main bars are arranged at the upper and lower stages of the beam member with a necessary concrete covering thickness, It is characterized by being exposed almost horizontally in an arrangement corresponding to at least four corners of the shape.

  According to a third aspect of the present invention, in the method for joining precast reinforced concrete beam members according to the first or second aspect, the stirrup is preliminarily moved around one side of the exposed beam main bar, and the connecting member is It is characterized by sliding after positioning and positioning to a required position.

In the joint structure of the precast reinforced concrete beam members according to the invention described in claim 4, the width and thickness of the beam members are stepped so as to coincide with the joint end portions of the beam members when approaching a substantially contact state. A notched portion is formed, the beam main reinforcement arranged in the beam member is exposed into the notch, and the tip of the exposed beam main reinforcement is formed in a hump shape;
Reinforcing bars with knots at both ends in a rectangular space formed by the beam main bars exposed in the notches of the beam members are provided in an opposing arrangement so that the beam members are almost in contact with each other. The connecting member formed in a letter shape is positioned so as to straddle almost evenly in the notch portion between the beam members, and the stirrup is arranged in the exposed beam main bar,
The notch part between the beam members is filled with a hardening material, and the precast reinforced concrete beam members are integrally joined to each other.

  According to a fifth aspect of the present invention, in the joint structure of the precast reinforced concrete beam members according to the fourth aspect, the beam main bars are arranged in the upper and lower stages of the beam member with a necessary concrete covering thickness. It is characterized by being exposed almost horizontally in an arrangement corresponding to at least four corners of the shape.

  The invention described in claim 6 is the joining structure of the precast reinforced concrete beam members according to claim 4 or 5, wherein the beam main bar is provided in a removable manner in a portion where the exposed portion is embedded in the beam member. It is characterized by being made.

  According to a seventh aspect of the present invention, in the joint structure between precast reinforced concrete beam members according to any one of the fourth to sixth aspects, the hump formed at the tip of the beam main bar is provided in a detachable manner. And / or the humps provided at both ends of the reinforcing bars forming the X-shaped connecting member are characterized in that the humps are detachable.

  The invention described in claim 8 is the joint structure of the precast reinforced concrete beam members according to any one of claims 4 to 7, wherein the hardener is concrete, grout, mortar, resin mortar, or epoxy resin, or It is characterized by being a combination of these.

According to the joining method of the precast reinforced concrete beam members according to claims 1 to 3 and the joining structure of the precast reinforced concrete beam members according to claims 4 to 8, a plurality of column main bars are provided below the PCa column member. Of course, the structure type (so-called reverse skewering method, reverse insertion column, see FIG. 7), as well as the structure type (so-called skewering method, see FIGS. 6A and B) where a plurality of column main bars are protruded above the PCa column member. It can be particularly preferably implemented. It is not necessary to move the PCa beam member 10 (or 11) in the horizontal direction when joining the PCa beam members 10 and 11, and by using a simple formwork material and filling a small amount of a hardening material such as concrete. The PCa beam members 10 and 11 can be reliably joined together. Therefore, a large-scale post-construction can be simplified, the construction period can be greatly shortened, and the workability, safety, and economy are excellent.
Moreover, since the joining operation | work of the said beam members 10 and 11 can be performed only from one side (for example, the inside of a veranda), it implements suitably for the joining structure of the PCa beam members used for construction of a veranda or a balcony. be able to. Thus, since the beam members 10 and 11 are normally securely restrained by a floor slab such as a veranda or a balcony, a stronger joining state that can sufficiently withstand out-of-plane deformation and axial deformation is realized. can do.
Further, since the knots 1a and 2a are provided at the tip of the beam main bar 1 and both ends of the reinforcing bar 2 forming the X-shaped connecting member 12, the shear force is effectively transmitted to the surrounding concrete. be able to. Therefore, the length of the beam main bar (rebar) can be shortened.

  The joining method and joining structure of precast reinforced concrete (PCa) beam members according to the present invention are implemented as follows in order to achieve the effects of the invention described above.

2 and 3 show an embodiment of a joint structure constructed by a precast reinforced concrete beam joining method according to the first aspect of the present invention.
The joint structure between the precast reinforced concrete beam members 10 and 11 is stepped so that the width and thickness of the beam members 10 and 11 coincide with each other when the joint ends of the beam members 10 and 11 are substantially brought into contact with each other. Notched portions 10a and 11b are formed in the beam member 10, and the beam main bars 1 arranged in the beam members 10 and 11 are exposed into the notched portions 10a and 11a, and the exposed beam main bars 1 are exposed. Is formed in a hump-like shape 1a. Further, the beam members 10 and 11 are provided so as to face each other substantially close to a contact state, and within a rectangular space formed by the exposed beam main bars 1 of the beam members 10 and 11 (see FIG. 3C). ), The connecting member 12 formed by combining the reinforcing bars 2 and 2 having the knots 2a and 2a at both ends in an X-shape is arranged so as to straddle substantially equally in the notches 10a and 11a between the beam members 10 and 11. The ribs 3 are arranged in the exposed beam main bars 1. Further, the notched portions 10a and 11a between the beam members 10 and 11 are filled with a hardener (not shown for the sake of illustration), and the precast reinforced concrete beam members are integrally joined together (the invention according to claim 4). ).

The PCa beam members 10 and 11 according to the illustrated example show a joint structure of beam members having a small width with respect to the beam beam, which is preferably used in the so-called reverse beam method, but is not limited thereto. Of course, the present invention can also be applied to a joining structure of PCa beam members having a large width dimension (for example, having a substantially square cross section).
Further, the beam members 10 and 11 according to the illustrated example are about 220 mm in width, the beam is about 750 mm, the notches 10a and 11a are both about 160 mm in width, and the notch length is about 500 mm. Of course, the present invention is not limited to this. However, it is preferable in terms of work that the notch length is at least about 500 mm.
Incidentally, the projecting portions of the joining end portions of the beam members 10 and 11 are chamfered at the end surfaces from the viewpoint of safety of joining work (see reference numeral 4 in the figure). Further, for the sake of illustration, some of the beam main bars, stirrups, etc., embedded in the beam members 10 and 11 are omitted.

  The beam main bars 1 are provided with a necessary concrete covering thickness (about 70 mm) and are arranged in the upper and lower stages of the beam members 10 and 11, and correspond to at least four corners of a square shape as shown in FIG. 3C. The arrangement is carried out by being exposed almost horizontally (inventions according to claims 5 and 2). The beam main bars 1 according to the present embodiment are provided in parallel at the upper and lower stages from the viewpoint of workability and economy, but the present invention is not limited to this. For example, as shown in FIG. 4A Thus, it can also carry out by providing in parallel arrangement | positioning 4 each at an upper stage and a lower stage. In short, as long as the beam main reinforcing bar 1 can secure a necessary concrete covering thickness and can form a rectangular space having a size capable of accommodating the connecting member 12, various types of beams can be used depending on the number and arrangement of the beams. It is possible to implement with the variation of.

  In addition, although the beam main reinforcement 1 ... which concerns on a present Example is each implemented by the one continuous beam main reinforcement 1, it is not limited to this, The exposed part is the part embed | buried in the beam members 10 and 11 The present invention can also be implemented by a structure that is detachably provided in the apparatus (invention of claim 6). For example, as shown in FIG. 5, a sleeve 5 having a threaded groove joined by a joining means such as welding at the distal end portion of the beam main reinforcing bar 1 corresponding to the buried portion of the beam member 10 (or 11) is buried. After the fact, the end portion of the beam main reinforcing bar 1 corresponding to the exposed portion where the end portion is threaded is integrated by screwing. In addition, a sleeve having a hollow portion joined by a joining means such as welding is embedded in the distal end portion of the beam main reinforcing bar 1, and after that, the beam main reinforcing bar 1 corresponding to the exposed portion is filled with a hardening material such as grout. It is also possible to carry out the integration by inserting the end portions of these.

  In the illustrated example, the shape of the head 1a formed at the distal end portion of the beam main reinforcing bar 1 is substantially hemispherical with the bottom surface provided on the front end side. However, the shape is not limited to this, and the outer diameter of the beam main reinforcing bar 1 ( As long as it has a diameter-expanded portion that is about twice as large as about 16 mm as an example, it can be implemented in a substantially square shape or a substantially spherical shape. The hump 1a according to the present embodiment is formed integrally with the beam main reinforcing bar 1, but the present invention is not limited thereto. A threaded groove is provided at the end of the beam main reinforcing bar 1, and the hump 1a having a threaded bolt is screwed into the hump 1a. The hump can also be carried out in a detachable manner, such as by making it into a form (the invention according to claim 7).

  The X-shaped connecting member 12 positioned in a rectangular space formed by the exposed beam main reinforcing bars 1... Has two X-shaped reinforcing bars 2 and 2 each having kumps 2a and 2a at both ends. Implemented in combination. Specifically, the individual reinforcing bars 2 constituting the X-shaped connecting member 12 are positioned in a suspended state by using binding wires (not shown) to the beam main bars 1 exposed in the notches 10a and 11a. ing. In the X-shaped connecting member 12 according to the present embodiment, the individual reinforcing bars 2 and 2 are implemented in a free state, but the central portion thereof is integrated by a joining means such as direct welding or the center thereof is integrated. The X-shaped connecting member 12 can also be configured by interposing a plate in the part and integrating them with a joining means such as welding. In the present embodiment, the connecting member 12 is formed using the two reinforcing bars 2, 2. However, the present invention is not limited to this, and the rectangular space formed by the beam main bars 1, and the required joining are formed. Depending on the strength, for example, as shown in FIG. 4B, the connecting members 12 can be formed by arranging the four reinforcing bars 2 alternately in a cross shape.

  By the way, the shape of the bumps 2a, 2a provided at both ends of the reinforcing bar 2 is substantially hemispherical with the bottom surface provided on the distal end side in the illustrated example, similar to the bump 1a formed on the beam main reinforcing bar 1 already described. However, the present invention is of course not limited to this, and the present invention can be implemented in a substantially rectangular shape or a substantially spherical shape as long as it has a diameter-expanded portion twice as large as the outer diameter of the reinforcing bar 2. Moreover, although the said humps 2a and 2a are integrally formed with the said reinforcing bar 2, it is not limited to this, The threaded groove is provided in the both ends of the reinforcing bar 2, and the hump 2a which has a threaded bolt is screwed in and integrated, and it implements. For example, the hump can be detachable (invention of claim 7).

  The stirrup 3 that wraps around the outer periphery of the exposed beam main reinforcement 1 of the beam members 10 and 11 can be arranged in advance at a predetermined interval around the beam main reinforcement 1. From the viewpoint of smoothly performing the positioning, it is preferable to arrange the bars after the positioning operation of the connecting member 12. By the way, in this embodiment, as will be described later, the stirrup 3 is placed in advance on one side (back side) in a state of being wrapped around the exposed beam main rebar 1 and is slid after the connecting member 12 is positioned. The bar is placed at the required position. Of course, the stirrups 3... Can be preliminarily moved around the hump 1a side of the beam main reinforcing bar 1 and slid after the connecting member 12 is positioned to be positioned at a required position. Invention). Although four stirrups 3... According to the present embodiment are used for the beam member 10 (or 11), the present invention is not limited to this, and the size of the notch 10a (11a) and the exposure of the beam main bar 1 are used. Depending on the length, it can be appropriately increased or decreased.

Moreover, although the beam main reinforcement 1 and the reinforcing bar 2 which concern on a present Example are implemented with the simple rod-shaped reinforcement, of course, it can implement also with deformed reinforcements, such as a screw joint reinforcement.
Furthermore, although the hardener according to the present embodiment is implemented with concrete, it can also be implemented with grout, mortar, resin mortar, or epoxy resin, or a combination thereof, depending on the required design strength. 8).

  Thus, the X-shaped connecting member 12 is positioned with good balance in the space formed by the beam main bars 1 exposed at the notches 10a, 11a of the beam members 10, 11 provided in the opposing arrangement, and the beam main bars 1. The precast reinforced concrete beam members 10, 11 are applied by placing a mold frame in a state where the ribs 3 are arranged in a well-balanced manner, and filling the space formed by the cutout portions 10a, 11a without any gaps. They are joined together with the required strength.

The joint structure of the precast reinforced concrete beam members described above is constructed by a joining method as shown in steps in FIGS. 1A to 1C (see FIGS. 1A to 1C).
That is, the method for joining the precast reinforced concrete beam members 10 and 11 is as shown in FIG. 1A, in which the beam members 10 and 11 having the above-described configuration are provided in an opposing arrangement and positioned. At this time, the stirrup 3 is gathered and wound around one side (the back side in the illustrated example) of the exposed beam main reinforcement 1.
When the beam members 10 and 11 are applied to a structure type in which a plurality of column main bars protrude above the PCa column member (so-called skewering method, see FIGS. 6A and B), the beam members 10 and 11 are moved in the horizontal direction. Since it cannot be positioned, both the beam members 10 and 11 are suspended and positioned in an opposing arrangement. The gap between the two beam members 10 and 11 can hardly be carried out without leaving a gap, but it is preferable to carry out with a gap of about 2 cm from the viewpoint of suspension work.

Next, as shown in FIG. 1B, the connecting member 12 (reinforcing bar 2) having the above-described configuration is connected to the beam main reinforcing bar 1, and a notch 10a of the beam members 10, 11 is used by using a binding wire (not shown). , 11a is positioned in a suspended state so as to extend almost evenly. Note that the connecting member 12 is positioned so as to be within a rectangular space formed by the beam main bars 1 (see FIGS. 3C, 4A, and B).
Subsequently, the four stirrups 3 gathered together on one side (the back side in the illustrated example) of the exposed beam main bar 1 are slid and positioned (arranged) at a required position as shown in FIG. 4C. (Invention of claim 3). At this time, the stirrup 3 may be fixed using a binding wire as necessary.
After that, a mold (not shown) is applied to the lower surface portion and both side surface portions of the beam members 10 and 11, and the space formed by the notches 10a and 11a is filled with a hardening material from above without any gaps. The precast reinforced concrete beam members 10 and 11 are integrally joined to each other with a required strength (the invention according to claim 1).

  The embodiments have been described with reference to the drawings. However, the present invention is not limited to the illustrated embodiments, and design modifications and application variations that are usually made by those skilled in the art are within the scope of the technical idea of the invention. Note that it includes the range. However, the shape of the notches 10a and 11a, the number and arrangement of the beam main reinforcing bars 1 are substantially bilaterally symmetric when viewed from the front direction and the plane direction of the beam members 10 and 11 positioned in the opposed arrangement. It is preferable to implement it in order to realize a good bonded state (see FIGS. 1 to 3).

AC is process drawing which showed in steps the joining method of the precast reinforced concrete beam members which concern on a present Example. It is the perspective view which showed the principal part of the joining structure of the precast reinforced concrete beam members which concern on a present Example. A is a top view which showed the principal part of the junction structure of the precast reinforced concrete beam members based on a present Example, B is the same front view, C is the same side view. A is a side view showing a variation of the arrangement of beam main bars, and B is a side view showing a variation of the connecting member. It is sectional drawing which showed the Example in the case of attaching a beam main reinforcement with a detachable type. A and B are the front views which showed the principal part of the joining structure of the precast reinforced concrete beam members based on a prior art. It is the front view which showed the principal part of the joining structure of the precast reinforced concrete beam members which concern on a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Beam main bar 1a Hump 2 Reinforcing bar 2a Hump 3 Stirrup 4 Chamfer 5 Sleeve 10 Beam member 10a, notch part 11 Beam member 11a, notch part 12 Connection member

Claims (8)

In the method of joining precast reinforced concrete beam members,
A beam main bar arranged in the beam member by providing a notch portion in which the width and thickness of the beam member are notched in a stepped shape so as to coincide with each other at the joint end portion between the beam members so as to be almost in contact with each other. Is exposed in the notch, the tip of the exposed beam main bar is formed in a hump shape, and the beam members are positioned close to each other in a contact state,
In the rectangular space formed by the main beam of the beam exposed at the notch of the beam member, a connecting member formed by combining reinforcing bars with knots at both ends in an X shape is provided in the notch of the beam members. Are positioned so as to extend almost evenly, and the stirrups are arranged in the exposed beam main bars, and then the notches between the beam members are filled with a hardener to integrate the precast reinforced concrete beam members together. A method for joining precast reinforced concrete beam members, characterized by joining.   2. The beam main bar is provided with a necessary concrete covering thickness, arranged in an upper stage and a lower stage of a beam member, and exposed substantially horizontally in an arrangement corresponding to at least four corners of a square shape. The joining method of the precast reinforced concrete beam members described in 2.   3. The precast according to claim 1, wherein the stirrup is preliminarily wound around one side of the exposed beam main bar and is slid and positioned at a required position after positioning the connecting member. A method of joining reinforced concrete beam members. In the joint structure between precast reinforced concrete beam members,
The beam members arranged in the beam members are provided with notch portions in which the width and thickness of the beam members are notched in steps so as to coincide with each other at the joint ends of the beam members. A main bar is exposed in the notch, and a tip of the exposed beam main bar is formed in a hump shape. In the rectangular space formed by the beam main bar exposed at the notch, a connecting member formed by combining reinforcing bars with knots at both ends in an X shape is almost evenly within the notch between the beam members. Positioned in a straddling arrangement, the stirrup is arranged in the exposed beam main bar,
A joint structure of precast reinforced concrete beam members, wherein the notched portions of the beam members are filled with a hardener and the precast reinforced concrete beam members are integrally joined.   5. The beam main bars are arranged in upper and lower stages of a beam member with a necessary concrete covering thickness, and are exposed almost horizontally in an arrangement corresponding to at least four corners of a square shape. The joint structure of precast reinforced concrete beam members described in 2.   6. The joint structure of precast reinforced concrete beam members according to claim 4 or 5, wherein the exposed portion of the beam main reinforcing bar is detachably provided at a portion embedded in the beam member.   The hump formed at the tip of the beam main reinforcing bar is provided in a detachable manner, and / or the hump provided at both ends of the reinforcing bar forming the X-shaped connecting member is the hump. The joint structure of precast reinforced concrete beam members according to any one of claims 4 to 6, wherein the joint structure is provided in a detachable manner.   The joint structure of precast reinforced concrete beam members according to any one of claims 4 to 7, wherein the hardener is concrete, grout, mortar, resin mortar, epoxy resin, or a combination thereof. .

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