JP2896988B2 - Construction method of prestressed masonry structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for constructing a prestressed masonry structure.

[0002]

2. Description of the Related Art An RM (Reinforced Masonry) structure is an R
It is a structure constructed using a masonry unit called an M unit. When this RM unit is classified from the material side, it can be considered as a "concrete RM unit" mainly composed of cement and a clay with high strength by firing clay. There is a "ceramic RM unit" formed.

The above RM unit is, for example, shown in FIGS.
As shown in (2), two flat plates 61 are integrally connected by a web 62, a cavity 63 is formed between the webs 62, and a recess 62a is formed in one or both of the upper and lower portions of the web 62. A feature of the RM unit is that when the RM units 60 are stacked, the cavity can be formed so as to be continuous in both the vertical and horizontal directions.

[0004] An RM structure using such an RM unit is constructed by masonrying the RM unit, arranging a reinforcing bar in cavities formed continuously in the vertical and horizontal directions, and further spreading concrete or concrete so as to reach all the cavities. Fill and build with mortar. Therefore, it can be said that the RM structure is an integrated reinforced concrete masonry structure. In addition, the RM structure does not require a large lifting machine or an external scaffold and is simple in operation, and therefore has a low construction cost and is most often used as a building wall in Japan.

On the other hand, the PM (Prestressed Masonry) structure uses a prestressed steel material (PC steel material) in place of a reinforcing bar in the longitudinal direction in the RM structure, and introduces prestress in the vertical direction of the wall by tensioning the steel. By doing so, the structure has improved seismic performance and crack resistance. Compared with the RM structure, it has higher seismic performance and cracking resistance, but has the disadvantage of higher construction cost. At the time of filing the present invention, although this structure has been used in Europe and the United States, it The construction results are almost nothing.

When the conventional PM structure is applied to a wall, FIG.
As shown in FIG. 5, in order to construct the PM structural wall 40, the PC steel 46 is inserted into the duct forming sheath tube 45, and the supporting plate 41b is fixed to the lower end of the PC steel 46. The lower ends of the sheath tube 45 and the PC steel 46 are buried in the foundation concrete 51 together with the supporting plate 41b. Then, the RM unit 47 is stacked on the sheath pipe 45 and the PC steel material 46 erected on the foundation concrete 51 through the hollow portion of the RM unit 47, and the reinforcing bar 50 is placed on the web of the RM unit 47 and extended into the horizontal hollow portion. RM unit 4
When the concrete 7 has been stacked at the predetermined height, the concrete 49 is spread so as to reach all the cavities in the vertical and horizontal directions of the RM unit 47.
Alternatively, the mortar is filled, and the beam 44 is formed at the upper end portion of the unit 47 that is laid. When the beam 44 and the concrete 49 are sufficiently hardened, the PC steel 46 is tensioned through the supporting plate 41a and the bolt 42 using a tensioning device such as a hydraulic jack, and finally into the sheath pipe 45 through the grout injection pipes 43a and 43b. Injecting the grout material creates a conventional PM structural wall 40.

[0007]

However, in the above-mentioned conventional PM wall 40 of the post-tension type, the PC
Before the steel material 46 was strained, the wall had insufficient strength, and there was a risk that the wall would collapse if an earthquake or the like occurred at this time.
This is because the vertical cavity of the RM unit 47 has P
Even though the C steel material 46 is inserted, the PC steel material 46 is arranged in the sheath tube 45, and the concrete 49 filled in the hollow portion cannot directly adhere and be integrated,
Therefore, there is a problem that the longitudinal strength of the wall body 40 is insufficient before the tension of the PC steel 46.

Further, it is not easy to tension the PC steel using a hydraulic jack or the like at the construction site, and a technician with specialized knowledge is required, resulting in an increase in construction costs due to labor costs. was there.

The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a structure having a sufficient structure even before the PC steel is tensioned to introduce prestress into the structure. It is an object of the present invention to provide a method for constructing a prestressed masonry structure that can have a proof strength and is easy to construct.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned object, and has as its gist a cylindrical steel rod having at least one open end, and a cylindrical steel rod inserted into the cylindrical steel rod. And a detachable tension holding means for holding the compressive force introduced into the steel bar and transmitting the compressive force to the cylindrical steel bar as a tensile force. Embedding the other end of the prestress introduction unit in the concrete portion of the structure, and erecting the masonry unit at one or more levels through the cavity of the masonry unit in the erecting prestress introduction unit Masonry step, the filling step of filling the grout material into the cavity of the stacked masonry unit, and the masonry step and the filling step are sequentially repeated, and the grout material is piled up to a predetermined height and the grout material is stacked. Up to required strength It turned into Once, in the construction method of the prestressed masonry structure, characterized in that it comprises a tension release process to remove the tension holding means.

In the method for constructing a prestressed masonry structure according to the present invention, the other end of the prestress introduction unit buried in the concrete portion of the structure means an end where no tension holding means is provided.

The method for constructing a prestressed masonry structure according to the present invention can be applied without particular limitation as long as the structure is constructed using a masonry unit. It can be applied to walls, walls in buildings, fences, retaining walls or chimney outer walls. In the construction method of the present invention, an RM unit such as the above-described concrete RM unit or ceramic RM unit can be used as a masonry unit.

In the method for constructing a prestressed masonry structure according to the present invention, lateral reinforcing bars may be arranged between the masonry step and the filling step or in the middle of the masonry step. For example, in the case of constructing a wall body, the masonry units are stacked by a predetermined number of levels so that the height in the horizontal direction is substantially constant, and then the reinforcing bars are extended substantially horizontally on the masonry units. The bar arrangement step may be performed, and thereafter, the masonry step is performed again. Alternatively, the reinforcing bar arrangement step may be performed after the masonry step, and the filling step may be performed immediately after that.

In the method for constructing a prestressed masonry structure according to the present invention, a cavity formed by stacking masonry units is formed with a continuous cavity in the vertical and horizontal directions (or horizontal and vertical directions). In the filling step, the grout material is filled so that the cavity portions in the vertical and horizontal directions are sufficiently distributed.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the accompanying drawings, but the present invention is not limited thereto.
FIG. 1 shows a prestressed masonry structure wall constructed by the construction method of the present invention, which is a cross-sectional view along the line II of FIG. 3, and FIG. 2 shows a prestress introduction unit used in the construction method of the present invention. 3 (a) is a front view showing the arrangement of the prestress introduction unit on the wall constructed by the construction method of the present invention, and FIG. 3 (b) is a IIIb-II of FIG. 3 (a).
FIG. 3C is a cross-sectional view taken along the line Ib, and FIG.
FIG. 3 is a sectional view taken along the line IIIc.

1 to 3, a prestressed masonry structural wall 10 constructed by the construction method of the present invention has a foundation concrete 15 constructed on the ground or in the ground, and a lower end portion embedded in the foundation concrete 15. A plurality of hollow PC steel bars 21 erected at predetermined intervals in a substantially vertical direction, and a plurality of RM units 60 stacked through the hollow PC steel bars 21 by penetrating the hollow portion 63 or 63a (see FIG. 6).
And a reinforcing bar 13 arranged in a lateral (substantially horizontal) cavity formed by the plurality of RM units 60 laid out, and a beam 1 formed on the RM unit 60 at the upper end.
2 as a main part.

Here, as the RM unit 60, the RM unit described in the section of the prior art in this specification can be used, and in addition to this, the end and the corner of the wall shown in FIG. An RM unit 60a, 60b, 60c, 60d, 60e having a planar shape as shown in (c) can be used.

The hollow PC steel rod 21 is made of the PC shown in FIG.
This PC steel bar unit 20 is a part of a steel bar unit 20. The PC steel bar unit 20 is a hollow PC steel bar 21 as a tubular tensile PC steel bar having at least one open end, and can be inserted into and removed from the hollow PC steel bar 21. The solid PC steel bar 22 as a reaction force PC steel bar accommodated in the housing, and members 23a and 23 for taking a reaction force to the hollow PC steel bar 22 and holding the hollow PC steel bar 21 in tension.
a ', 23b'23c and a tension holding member 23, the main part of which is formed.
Are screwed to the hollow PC steel rod 22.

The hollow PC steel rod 21 is formed in a cylindrical shape, and the RM unit 60 is used to introduce prestress into the masonry structure wall 40 formed by assembling the RM unit 60.
Are arranged in the hollow portions 63 and 63a of the
Grout material 1 such as concrete filled in 3,63a
4 is directly attached to the surface thereof, and screw threads 25 and 26 are engraved on the outer periphery of both ends.

The solid PC steel bar 22 is used to take a reaction force when a tensile force is applied to the hollow PC steel bar 21. Further, a cap nut 23a 'as the tension holding member 23 is screwed to a male screw at one end of the hollow PC steel rod 11, while the nut 23a is screwed to a male screw at the other end. Also, the top 23c is connected to the nut 2 so as to abut the solid PC steel bar 22 inserted into the hollow PC steel bar 11.
A bolt 23b is screwed into a screw thread on the inner periphery of the nut 23a so as to be inserted into the nut 3a and to seal the frame 23c in the nut 23a.

In the PC steel rod unit 20 having the above-described structure shown in FIG. 2, a tensile force is previously applied to the hollow PC steel rod 11 at a factory or the like. That is, a pressing force in the direction of arrow X is applied to the solid PC steel bar 22 via the top 23c by a jack device or the like, and the solid PC steel bar 22 is pushed into the hollow PC steel bar 21. Then, the bolt 23b is screwed into the nut 23, and the pushed solid PC steel bar 22 is fixed via the top 23c in a compressed state. The solid PC steel rod 22 thus compressed by the pressing force has its tip abutting on the cap nut 23a 'and its rear end abutting on the top 23c, and tries to restore to its original length. Hollow P by force
A tensile force is introduced into the C steel bar 21.

The PC steel bar unit 20 in which the tensile force is previously introduced into the hollow PC steel bar 21 is disposed at a predetermined position of the structure, and is concretely attached so as to directly adhere around the hollow PC steel bar 21. When a grout material such as mortar or mortar is filled and the grout material has hardened to a predetermined strength or more, the nut 23 a as the tension holding member 23 is loosened. As a result, the tensile force introduced into the hollow PC steel bar 21 is released, and the hollow PC steel bar 21 is contracted and prestress can be introduced into the structure via the grout material adhered around. The PC steel bar unit 20 includes a solid PC steel bar 22 and a tension holding member 23.
23c, nut 23a and bolt 23b
Is removed after the introduction of prestress, and other hollow PC
The steel bar 21, the cap nut 23a and the nut 24 are embedded in the structure.

Next, a method for constructing a prestressed masonry wall of the present invention will be described. When the prestressed masonry structure wall 10 is constructed, first, the PC steel bar units 20 are erected at predetermined locations at predetermined intervals as shown in FIGS. The foundation concrete 15 is formed on the foundation ground 18 so as to embed the lower end of 20, ie, the cap nut 23a and the lower end of the hollow PC steel rod 21 integrally. At this time, the reinforcing bar 16 is provided under the cap nut 23a.
May be arranged.

After the foundation concrete 15 has hardened, the cavity 63 of the RM unit 60 is passed through the PC steel bar unit 20 and stacked (see FIG. 3 (a)).
The RM unit 60 is stacked so that the C steel bar unit 20 is disposed at the center between the hollow portions 63a and 63a (FIG. 3).
(c)). Then, when the RM units 60 are stacked by a predetermined height, the reinforcing bars 13 are arranged on the concave portions 62a of the webs 62 of the RM unit 60 in order to arrange the reinforcing bars 13 in hollow portions formed substantially in the horizontal direction. . Note that R
If the work of stacking the M units 60 is performed while applying an adhesive to the joints 60a, the integrity of the wall during construction can be improved.

In parallel with the work of stacking the RM units 60 and the work of arranging the reinforcing bars 13, the grout material 14 such as concrete is appropriately filled in the vertical cavity 63 and the horizontal cavity. Fill. Here, the grout material 14 is sufficiently adhered to the surface of the hollow PC steel rod 21 and is filled so as to spread densely in the cavity formed in the vertical and horizontal directions (substantially vertical and horizontal directions). For example, when non-shrink mortar is used as the grout material 14, it hardens in about 2 to 3 days after filling and introduces prestress into a wall composed of a plurality of RM units 60 stacked. Even before, the RM unit 60 and the hollow PC steel bar 21 can be integrated, and the proof strength of the wall during construction can be improved.

As described above, when the RM unit 60 is stacked up to a predetermined height while filling the grout material 14, the screw threads 25 of the hollow PC steel rod 21 are sufficiently embedded in the grout material 14 and the uppermost portion is formed. The beam 12 having the concave portion 12a is formed on the RM unit 60. The beam 12 is formed so that the upper end of the PC steel bar unit 20, that is, the tension holding member 23 projects from the recess 12a.
In addition, the beam 12 may be formed by fixing a prestress member manufactured in advance in a precast factory or the like on the RM unit 60, or by providing a mold (not shown) on the RM unit 60, It may be formed by cast-in-place concrete.

When the beam 12 having sufficient strength is formed and the grout material 14 is hardened, the nut 23a of the PC steel bar unit 20 is removed with a wrench (not shown) or the like, and the hollow P is removed.
The solid PC steel bar 22 is extracted from the inside of the C steel bar 21. As a result, the tensile force acting on the hollow PC steel bar 21 from the solid PC steel bar 22 is released.
Is prestressed on the masonry structure wall 10 by the plurality of RM units 60 through the surrounding grout material 14 to shrink.
(Compressive stress) can be introduced. Since the prestress can be introduced by such a simple device, work can be performed without impairing the workability even in a narrow place such as the top of a wall.

After the prestress has been introduced, a cap 25 is fitted on the upper end of the hollow PC steel bar 21 and
When 2a is filled with the grout material 11, the prestressed masonry structure wall 10 is completed. Although not shown, a prestressed masonry structure wall can be further provided on the prestressed masonry structure wall 10.

[0029]

According to the present invention, a steel rod is press-fitted into a cylindrical steel rod, and a tensile force is previously introduced into the cylindrical steel rod, and this tensile force is held by detachable tension holding means, and the tension is held. A prestress introduction unit capable of introducing a compressive stress from a cylindrical steel bar to a structure by removing the means is disposed so as to be inserted into the cavity of the RM unit, and a grout such as concrete or mortar is inserted into the cavity. Since the material is injected to construct the structure, even before the prestress is introduced, the grout material directly adheres to the tubular steel bar made of PC steel, and the tubular steel bar acts as a reinforcing bar. Therefore, even when an external force such as an earthquake acts during the construction, a sufficient strength capable of resisting the external force can be provided to the structure.

[Brief description of the drawings]

FIG. 1 is a sectional view of a prestressed masonry structure constructed by a construction method of the present invention.

FIG. 2 is a sectional view of a prestress introduction unit used in the construction method of the present invention.

FIG. 3A is a front view showing an arrangement of a prestress introduction unit on a wall constructed by the construction method of the present invention, and FIG. 3B is a cross-sectional view taken along the line IIIb-IIIb of FIG. ,
(c) is a sectional view taken along line IIIc-IIIc of (a).

FIG. 4 is a sectional view of a wall to which a conventional prestressed masonry structure is applied.

FIG. 5 is a perspective view of a wall to which a conventional prestressed masonry structure is applied.

FIG. 6A is a perspective view showing a conventional RM unit, and FIG. 6B is a plan view of the RM unit of FIG.

[Explanation of symbols]

 Reference Signs List 20 PC steel rod unit (prestress introduction unit) 21 Hollow PC steel rod (cylindrical steel rod) 22 Solid PC steel rod (steel rod) 23 Tension holding member (tension holding means) 49 Grout material 60 RM unit (set) Loading unit) 51 Foundation concrete (concrete part)

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) E04B 2/02 E04C 1/10

Claims (1)

(57) [Claims] 1. A cylindrical steel rod having at least one open end, a steel rod inserted into the cylindrical steel rod to introduce a compressive force, and holding the compressive force introduced to the steel rod. And a step of burying the other end of the prestress introduction unit having detachable tension holding means for transmitting the compressive force to the cylindrical steel bar as a tensile force, and burying the other end in the concrete portion of the structure. A masonry step of stacking one or more masonry units through the cavity of the masonry unit in the standing prestress introduction unit, and a filling step of filling grout material into the cavity of the masonry unit thus piled up. A step of successively repeating the masonry step and the filling step, stacking the masonry units to a predetermined height and, when the grout material has hardened to a required strength, removing the tension holding means, and a tension releasing step. Pre Construction method of stress masonry structure.