JPH09273246A - Construction method of prestress assembly structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a construction method of a prestress assembly structure which can provide the structure with sufficient proof stress even before prestress is introduced into the structure by stretching and tightening a PC steel material. SOLUTION: A prestress introduction unit is provided with a cylindrical steel bar 21 of which at least one end is opened, a steel bar which is inserted into the inside of the cylindrical steel bar and introduces compression force, and a stretching and tightening hold means which holds compression force introduced into the steel bar, transmits compression force as tensile force to the cylindrical steel bar, and can be mounted and dismounted freely. The other end of the prestress introduction unit is embedded into a concrete part 15 of a structure to erect it. This construction method includes an assembly process in which a cavity part of a unit 60 for assembly passes through the prestress introduction unit which is erected to pile up the units 60 for assembly by one step or more, a filling process in which a grout material 49 is filled into the cavity part of the units 60 for assembly which are piled up, and a stretching and tightening release process in which the units for assembly are piled up to a predetermined height by repeating the assembly process and the filling process sequentially and a stretching and tightening hold means is removed after the grout material is hardened.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art RM (Reinforced Masonry) structures are
It is a structure constructed using a single masonry unit called M unit, and if this RM unit is classified from the material aspect, it will be "concrete RM unit" mainly composed of cement, and clay will be fired for high strength. There is a formed "ceramic RM unit".

The above RM unit is shown, for example, in FIGS. 6 (a) and 6 (b).
As shown in FIG. 2, the two flat plates 61 are integrally connected by a web 62, a cavity 63 is formed between the webs 62, 62, and a recess 62 a is formed in one or both of the upper and lower sides of the web 62. However, it is a feature of the RM unit that the cavity portion can be formed so as to be continuous in both the vertical and horizontal directions by stacking the RM units 60.

The RM structure using such an RM unit is constructed by stacking the RM units, arranging the reinforcing bars in the cavity formed continuously in the vertical and horizontal directions, and further by using concrete or Fill and build with mortar. Therefore, it can be said that the RM structure is an integrated reinforced concrete masonry structure. Also, the RM structure does not require a large lifting machine or an outer scaffold, and the work is simple. Therefore, the construction cost is low and it is most often used as a wall of a building in Japan.

On the other hand, PM (Prestressed Masonry) structure uses prestressed steel material (PC steel material) mainly in place of longitudinal reinforcing bars in RM structure and tensions this to introduce prestress in the vertical direction of the wall. The structure has improved seismic resistance and crack resistance. Compared to the RM structure, it has high earthquake resistance and cracking resistance, but its construction cost is disadvantageous. At the time of the application of this invention, there are many construction results in Europe and the United States, but in Japan The construction results are almost zero.

When the above-mentioned conventional PM structure is applied to a wall, FIG.
As shown in FIG. 5, in order to construct the PM structure wall 40, the PC steel material 46 is inserted into the duct forming sheath tube 45, and the pressure bearing plate 41b is fixed to the lower end of the PC steel material 46. The lower ends of the sheath pipe 45 and the PC steel material 46 are embedded in the basic concrete 51 together with the bearing plate 41b. Then, the sheath pipe 45 and the PC steel material 46 erected on the foundation concrete 51 are piled up through the cavity of the RM unit 47, the reinforcing bars 50 are placed on the web of the RM unit 47, and extended in the cavity in the lateral direction. RM unit 4
After stacking 7 to the specified height, concrete 49 should be spread over all cavities of the RM unit 47 in the vertical and horizontal directions.
Alternatively, the beam 44 is formed on the upper end portion of the unit 47 which is filled with mortar and built up. When the beam 44 and the concrete 49 are sufficiently hardened, the PC steel material 46 is tensioned through the pressure bearing plate 41a and the bolts 42 using a tensioning device such as a hydraulic jack, and finally through the grout injection pipes 43a and 43b into the sheath pipe 45. When the grout material is injected, the conventional PM structure wall 40 is completed.

[0007]

However, in the above-mentioned conventional post-tensioning PM structure wall 40, the PC
Before the steel material 46 was strained, the wall had insufficient proof stress, and there was a risk that the wall would collapse if an earthquake or the like occurred at this time.
Because, in the vertical cavity of the RM unit 47, P
Even if the C steel material 46 is inserted, the PC steel material 46 is arranged in the sheath pipe 45, and the concrete 49 filled in the cavity cannot be directly attached and integrated,
Therefore, before the tension of the PC steel material 46, the longitudinal proof stress of the wall body 40 is insufficient.

Further, the work of tensioning the PC steel material using a hydraulic jack or the like at the construction site is not easy, and an engineer with specialized knowledge is required, which causes an increase in construction cost due to labor cost. was there.

The present invention has been made in order to solve the above-mentioned conventional problems, and an object thereof is to provide a sufficient structure even before the PC steel material is tensioned to introduce prestress into the structure. An object of the present invention is to provide a method for constructing a prestressed masonry structure which has a proof stress and is easy to construct.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above objects, and its gist is to provide a tubular steel rod having at least one end opened and to insert the tubular steel rod into the tubular steel rod. And a detachable tension holding means for holding the compressive force introduced to the steel rod and transmitting the compressive force to the tubular steel rod as a tensile force. The step of embedding the other end of the prestressing unit in the concrete portion of the structure to stand upright, and stacking the masonry unit more than one stage through the cavity of the masonry unit in the standing upright prestressing unit. The masonry step, the filling step of filling the cavity portion of the stacked masonry unit with grout material, the masonry step and the filling step are sequentially repeated, and the grout material is piled up to a predetermined height. 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 of constructing a prestressed masonry structure according to the present invention, the other end of the prestressing introduction unit buried in the concrete portion of the structure means the end where no tension holding means is provided.

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

In the method of constructing a prestressed masonry structure according to the present invention, transverse reinforcing bars may be arranged between the masonry step and the filling step or during the masonry step. For example, when constructing a wall, a reinforcing bar is constructed by stacking a predetermined number of stacking units so that the height in the horizontal direction is substantially constant, and then extending reinforcing bars in a substantially horizontal direction above the stacking units. The arranging step may be performed, and then 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, since a cavity portion which is continuous in the vertical and horizontal directions (or horizontal and vertical directions) is formed in the structure formed by stacking the units for masonry, In the filling step, the grout material is filled so as to sufficiently fill the hollow portions in the vertical and horizontal directions.

[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 is a prestressed masonry structure wall constructed by the construction method of the present invention and is a cross-sectional view taken along the line I-I of FIG. 3, and FIG. 2 is a prestress introduction unit used in the construction method of the present invention. 3 (a) is a front view showing the arrangement of prestressing units in 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 line Ib, and FIG. 3C is IIIc- of FIG.
It is a sectional view taken along the line IIIc.

1 to 3, a prestressed masonry structure 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 is embedded in the foundation concrete 15. , A plurality of hollow PC steel rods 21 erected at a predetermined interval in a substantially vertical direction, and a plurality of RM units 60 stacked by penetrating the hollow PC steel rods 21 with a cavity 63 or 63a (see FIG. 6).
And a reinforcing bar 13 arranged in a lateral (substantially horizontal) cavity formed by a plurality of stacked RM units 60, and a beam 1 formed on the RM unit 60 at the upper end.
2 and 2 are provided as main parts.

Here, as the RM unit 60, the RM unit described in the section of the prior art of this specification can be used, and in addition to this, at the ends and corners of the wall body, FIG. The planar RM units 60a, 60b, 60c, 60d and 60e as shown in (c) can be used.

The hollow PC steel rod 21 is the PC shown in FIG.
This PC steel rod unit 20 is a part of the steel rod unit 20, and this PC steel rod unit 20 can be inserted into and removed from the hollow PC steel rod 21 as a tubular tensile PC steel rod with at least one end open. The solid PC steel rod 22 as a reaction force PC steel rod housed in and the respective members 23a, 23 for holding the hollow PC steel rod 21 under tension by applying a reaction force to the hollow PC steel rod 22.
The main part is composed of a tension holding member 23 composed of a ', 23b'23c, and a nut 24 for fixing.
Is screwed into the hollow PC steel rod 22.

The hollow PC steel rod 21 is formed in a tubular shape, and in order to introduce prestress to the masonry structure wall 40 formed by laminating the RM unit 60, the RM unit 60 is formed.
Of the hollow portion 63, 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 peripheries of both ends.

The solid PC steel rod 22 is used to take a reaction force when a tensile force is introduced into the hollow PC steel rod 21. Further, the cap nut 23a 'as the tension holding member 23 is screwed into the male screw at one end of the hollow PC steel rod 11, while the nut 23a is screwed into the male screw at the other end. Further, the top piece 23c is attached to the nut 2 so as to come into contact with the solid PC steel rod 22 inserted in the hollow PC steel rod 11.
The bolt 23b is screwed into the screw thread on the inner periphery of the nut 23a so that the top 23c is inserted into the nut 3a and is sealed in the nut 23a.

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

The PC steel rod unit 20 in which the tensile force has been introduced into the hollow PC steel rod 21 in advance in this way is arranged at a predetermined position of the structure, and concrete is attached so as to be directly attached around the hollow PC steel rod 21. When the grout material such as mortar or the like is filled and hardened until the grout material exhibits a predetermined strength or more, the nut 23a as the tension holding member 23 is loosened. As a result, the tensile force introduced into the hollow PC steel rod 21 is released, the hollow PC steel rod 21 contracts, and prestress can be introduced into the structure through the grout material attached around the hollow PC steel rod 21. In addition, the solid PC steel rod 22 and the tension holding member 23 in the configuration of the PC steel rod unit 20 described above.
23c, nut 23a and bolt 23b
Is removed after introducing prestress, and other hollow PC
The steel rod 21, the cap nut 23a, and the nut 24 are embedded in the structure.

Next, a method of constructing a prestressed masonry structure wall of the present invention will be described. When constructing the prestressed masonry structure wall 10, first, as shown in FIGS. 3 (a) to (c), the PC steel rod units 20 are erected at predetermined locations at predetermined intervals, and the PC steel rod units are installed. The foundation concrete 15 is formed on the foundation ground 18 so that the lower end of 20, that is, the cap nut 23a and the lower end of the hollow PC steel rod 21 are integrally embedded. At this time, the reinforcing bar 16 is provided below the cap nut 23a.
Etc. may be arranged.

After the foundation concrete 15 is hardened, the cavity 63 of the RM unit 60 is then passed through the PC steel rod unit 20 to be piled up (see FIG. 3 (a)), or P
The RM unit 60 is stacked so that the C steel rod unit 20 is arranged at the center of the hollow portions 63a and 63a (see FIG. 3).
(c)). Then, when the RM units 60 are piled up by a predetermined height, the reinforcing bars 13 are arranged on the recesses 62a of the web 62 of the RM unit 60 in order to arrange the reinforcing bars 13 in the cavity formed in the substantially horizontal direction. . Note that R
If the work of stacking the M units 60 is performed while applying the adhesive to the joint portion 60a, the integrity of the wall body during the construction can be improved.

Further, in parallel with the above-mentioned work of stacking the RM unit 60 and work of arranging the reinforcing bars 13, the grout material 14 such as concrete is timely provided in the vertical cavity portion 63 and the horizontal cavity portion. 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 be densely distributed in the cavities formed in the vertical and horizontal directions (substantially vertical and horizontal directions). When non-shrink mortar, for example, is used as the grout material 14, it is hardened in about 2 to 3 days after filling, and prestress is introduced into the wall body composed of a plurality of stacked RM units 60. Even before, the RM unit 60 and the hollow PC steel rod 21 can be integrated, and the yield strength of the wall body under construction can be improved.

As described above, when the RM unit 60 is piled up to a predetermined height while being filled with the grout material 14, the screw thread 25 of the hollow PC steel rod 21 is sufficiently embedded in the grout material 14 and the uppermost portion The beam 12 having the recess 12a is formed on the RM unit 60. The beam 12 is formed so that the upper end of the PC steel rod 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 of cast-in-place concrete.

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

After introducing the prestress, a cap 25 is fitted on the upper end of the hollow PC steel rod 21 to form the recess 1 of the beam 12.
When 2a is filled with grout material 11, the prestressed masonry structure wall 10 is completed. Although not shown, a prestressed masonry structure wall may be further provided on the prestressed masonry structure wall 10.

[0029]

According to the present invention, the steel rod is press-fitted into the tubular steel rod to introduce a tensile force to the tubular steel rod in advance, and the tensile force is held by the detachable tension holding means. A prestressing unit capable of introducing a compressive stress from the tubular steel rod into the structure by removing the means is arranged so as to be inserted into the cavity of the RM unit, and the grout of concrete, mortar or the like is placed in the cavity. Since the material is injected to construct the structure, the grout material directly adheres to the tubular steel rod which is the PC steel material even before the prestress is introduced, and the tubular steel rod acts as a reinforcing bar. Therefore, even if an external force such as an earthquake acts during the construction, it is possible to impart sufficient proof stress to the structure to withstand the external force.

[Brief description of drawings]

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

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

FIG. 3 (a) is a front view showing an arrangement of prestressing units in a wall constructed by the construction method of the present invention, and FIG. 3 (b) is a cross-sectional view taken along line IIIb-IIIb in (a). ,
(c) is a sectional view taken along line IIIc-IIIc in (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]

 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 Basic concrete (concrete part)

Claims (1)

[Claims] 1. A tubular steel rod having at least one end opened, a steel rod inserted into the tubular steel rod to introduce a compressive force, and a compressive force introduced to the steel rod is retained. At the same time, a step of embedding the other end of the prestress introduction unit provided with detachable tension holding means for transmitting the compressive force as a tensile force to the tubular steel rod by embedding it in the concrete portion of the structure. A stacking step of stacking the stacking unit in one or more stages through the cavity of the stacking unit in the standing prestressing unit, and a filling step of filling the cavity of the stacked stacking unit with grout material. The step of repeating the stacking step and the filling step to stack the unit for stacking up to a predetermined height and when the grout material has hardened to a required strength, release the tension holding means and release the tension. Pre Construction method of stress masonry structure.