JP3769673B2 - Construction method of concrete structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In the construction of a concrete structure that is a long object such as a pillar, a bridge pier, a beam, or a wall, the present invention provides a projection cross-section of a part of an annular band that is arranged in a transverse section so as to surround a plurality of main bars. The present invention relates to a method for constructing a concrete structure that is constructed by overlapping.
[0002]
[Prior art]
For example, when constructing a columnar concrete structure such as a column or a bridge pier, a band reinforcing bar is usually arranged so as to surround the outer periphery of a plurality of main bars b erected in the vertical direction. In general, the reinforcing bars are arranged by inserting reinforcing bars formed in an elliptical shape, an oval shape or a rectangular shape according to the outer peripheral shape of the concrete structure from above the main reinforcing bars b.
Then, instead of the band reinforcing bar, a plurality of annular band reinforcing bars a are arranged so that a part of the projected cross section of the annular band a overlaps, using an annular ring band a surrounding a part of the main reinforcing bar b group. There is a case. This bar arrangement is called interlocking arrangement, and an example using a circular annular band a is disclosed in Patent Document 1, and an example in which a spiral annular band is superimposed is disclosed in Patent Document 2. ing.
[0003]
[Patent Document 1]
JP 2001-193283 A (FIG. 12)
[Patent Document 2]
JP 2001-248305 A (FIG. 1)
[0004]
[Problems to be solved by the invention]
The above-described conventional method for constructing a concrete structure with interlocking reinforcement has the following problems.
<I> When interlocking bar arrangement is performed using circular independent circular band a, the left and right annular band a is inserted alternately, or a part of the circular band a is connected and inserted step by step. (See FIG. 7). For this reason, it took time and work efficiency was poor. In some cases, the continuous band group c may be manufactured and arranged with a single continuous reinforcing bar, but the structure of the continuous band group c becomes complicated and takes time to manufacture (see FIG. 8).
<B> When inserting a spiral annular strip, it is necessary to suspend the spiral annular strip on the top of the columnar structure, and thus a large crane is often required. In addition, in order to manufacture a spiral annular band in advance, the size of the work yard or the transportation means is limited.
<C> When the aspect ratio of the cross section of the concrete structure is increased, three (Figs. 7 and 8), four (not shown) or more annular strips a are arranged. The operation of placing the annular band a having a plurality of overlapping portions in the region where the main bar b stands is complicated and takes time.
[0005]
OBJECT OF THE INVENTION
The present invention was made in order to solve the above-described conventional problems, and the construction of a concrete structure in which interlocking bar arrangement can be easily performed even when the number of annular band bars arranged on the projected cross section increases. It aims to provide a method.
It is another object of the present invention to provide a method for constructing a concrete structure in which interlocking bar arrangement can be performed even when the aspect ratio of the cross section of the concrete structure is increased.
It is another object of the present invention to provide a method for constructing a concrete structure in which structural strength can be sufficiently secured by a strong bonding force.
The present invention achieves at least one of these objects.
[0006]
[Means for Solving the Problems]
In order to achieve the above-described object , the first invention of the present application is the construction method of a concrete structure in which a part of the annular band surrounding the main reinforcement of the concrete structure is overlapped and constructed in a projected section. Annular band muscle group that overlaps a part of the projected section and an annular band group that overlaps another part of the projected section are arranged without overlapping, and the side between both annular band groups The link bars composed of the main body part and the legs provided at both ends thereof are arranged so as to be stretched over both the main muscles surrounded by one annular band group and the main bars surrounded by the other annular band group. It is a method characterized in that it is connected and filled with concrete to form a concrete structure in which the annular rebars are integrated .
[0007]
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1
Embodiment 1 of the present invention will be described below with reference to the drawings.
[0008]
<A> Interlocking bar arrangement There is a bar arrangement method called interlocking bar arrangement in which a part of the annular band 2 having a circular projection or a circular shape such as a polygon is overlapped with the adjacent annular band 2. . In a long concrete structure 4 such as a column, a pier, a beam, or a wall, a plurality of main bars 3 are arranged in the axial direction. Interlocking bars are a part of this group of main bars 3 surrounded by the annular band 2 and overlapped with a part of the adjacent annular band 2 in the projection cross section.
In the present invention, a concrete structure is constructed by an annular band group 20 in which a plurality of annular band bars 2 are overlapped at a part of the projected cross section and a link bar 1 connecting the annular band group 20.
[0009]
<B> Annular band Reinforcing band 2 is a member corresponding to a band reinforcing bar having a closed shape whose projection section is annular. As the annular shape, a circle, an oval, an ellipse, a polygon, or the like can be adopted. The annular band 2 is usually formed of a reinforcing bar, a PC steel wire, a PC steel strand, a flexible reinforcing bar, or the like, but a tensile material manufactured with a nonferrous metal, carbon fiber, aramid fiber, or the like can also be used.
The annular band 2 can be manufactured as an independent annular band 2 by processing a single reinforcing bar into a circular shape, for example. The annular band 2 formed in this way is used by being arranged in a plurality of stages at intervals in the axial direction of the main bar 3.
Further, the annular band 2 can be formed by forming one long reinforcing bar in a spiral shape.
[0010]
<C> Annular band muscle group The annular band group 20 is an aggregate in which a plurality of annular band 2 is arranged so that a part thereof overlaps in the projected cross section.
The annular band group 20 can be formed by connecting in advance circular ring bands 2 and 2 that are independent of each other. Further, the annular band muscle group 20 may be formed while being inserted into the left and right main muscles 3 group.
Alternatively, a part of the spiral annular strips 2 and 2 may be overlapped to form the annular strip group 20.
Furthermore, as shown in FIG. 8, a publicly known annular band a group that is continuous in the lateral direction is formed by a single long reinforcing bar, and a plurality of annular band groups are formed continuously in the vertical direction. The continuous band muscle group c can also be used as the annular band muscle group 20.
Here, from the viewpoint of workability, it is preferable to use a ring band group 20 formed of two rows of ring band 2 and 2.
[0011]
<D> Link muscle The link muscle 1 is a member for connecting the annular band muscle groups 20.
The link line 1 is composed of a main body part 11 and leg parts 12 provided at both ends thereof. For example, the U-shaped link bar 1 can be manufactured by bending the both sides of a straight main body portion 12 at right angles to form the leg portions 12. In addition, there is a shape in which the boundary between the main body portion 11 and the leg portion 12 is not necessarily clear, such as a C-shaped link bar 1 having an opening.
The link muscle 1 is disposed on the side portion between the annular band groups 20a and 20b. The link streaks 1 are preferably arranged so that the two link streaks 1 face each other on the projected cross section (see FIG. 1). The leg portions 12 of the link muscles 1 that face each other may be separated as shown in FIG. 1, or may overlap or contact each other.
Moreover, the link reinforcement | stripe 1 should just overlap with the cyclic | annular strip reinforcement 20 on both sides in a projection cross section, and does not necessarily need to be fixed to the annular reinforcement 20 by welding.
[0012]
<E> Construction method of concrete structure Annular band 20 is arranged in a main bar group in which a plurality of main bars 3 are erected.
The annular band muscle groups 20a and 20b are arranged so as not to overlap each other (see FIG. 1). Arrangement of the annular band groups 20a and 20b so as not to overlap each other is performed in consideration of workability, and does not prohibit contact between the annular band groups 20a and 20b.
Then, the link muscle 1 is inserted from the side between the annular band groups 20a and 20b. Since the link muscle 1 is open between the leg portions 12 and 12 at both ends, the link muscle 1 can be easily inserted between the annular band muscle groups 20a and 20b. The link muscle 1 is disposed so as to span, for example, the main muscle 3a surrounded by one annular band muscle group 20a and the main muscle 3b surrounded by the other annular band muscle group 20b.
FIG. 2 shows a side view when the main muscle 3 group is surrounded by a plurality of stages of annular band muscle groups 20 a and 20 b and the link muscle 1.
[0013]
The long concrete structure 4 may be constructed hollow because its own weight becomes too large when it is constructed solid by filling all the cross sections with concrete. FIG. 3 is a cross-sectional view of an embodiment in which a hollow pier 4a is constructed.
The outer shell main body having a hollow cross section as shown in FIG. 3 has a large aspect ratio. For this reason, if it is going to perform interlocking arrangement | positioning which has arrange | positioned the annular band 2, it is necessary to arrange | position the 3 or more series of annular band 2 continuously.
Thus, the link bars 1 of the present invention connect the annular band groups 20 so that the same effect as the interlocking bars can be obtained as a whole. For example, the bridge pier 4a having a hollow cross section is constructed by the two annular band groups 20 and the annular band 2 arranged at the corner. Since the two annular band groups 20 have good workability, the two annular band groups 20 are arranged between the two annular band groups 2 arranged at the corners. Then, the annular band muscles 20 and 20 are connected by the link muscle 1a, and the annular band muscle group 20 and the annular band muscle 2 are connected by the link muscle 1b. By using the link bars 1a and 1b as described above, a structure having a large aspect ratio such as a hollow cross section or a wall can be constructed with interlocking bars. In addition, the link reinforcement | strut 1b which connects the annular band 2 of a corner | angular part, and the annular band group 20 can be abbreviate | omitted.
[0014]
<Effect> Effect of Link Muscle FIG. 4 is a diagram showing a result of an experiment performed for confirming the effect of arranging the link muscle 1.
In the experiment, the link streaks 1 are arranged as shown in FIG. 1 (“with link streaks” in FIG. 4), and the ring streak groups 20a and 20b are arranged without the link streaks (FIG. 4). No link link) and the case where the outer periphery of one group of main bars is surrounded by one row of the circular band 2 ("conventional band reinforcement" in FIG. 4).
Here, the main rebar 3 used in the experiment is a deformed rebar (D13) having a diameter of 13 mm, the annular rebar 2 is a deformed rebar (D6) having a diameter of 6 mm, and the link rebar 1 is a deformed rebar (D6) having a diameter of 6 mm. In addition, loading is performed by applying an antisymmetric bending moment in a direction perpendicular to the specimen bridge axis in a state where a constant axial stress (1.5 MPa) is applied by an L-shaped force frame. The force history is positive / negative alternating loading in which the member angles 1/1600, 1/800 are repeated for 1 cycle each, and then 1/400, 1/200, 1/100,.
[0015]
FIG. 4 is a relationship curve between shear force and displacement of each specimen calculated based on the nominal strength of the material. From this figure, it can be seen that the placement of the link bars 1 clearly improves the strength of the concrete structure against shearing forces. In addition, when observing the state of fracture of the specimen by the test, in the case of “without link reinforcement”, shear cracks concentrate between the annular band groups 20a and 20b at a force of 1/200 to 1/100, and the two It shifted to the destruction situation as a pillar. On the other hand, in the case of “with link streaks”, it was possible to maintain a substantially healthy state even with repeated loading of 1/100.
FIG. 5 shows the relationship between the load and displacement of each specimen. According to FIG. 5A showing the test value and the calculated value in the case of “no link reinforcement”, in the case of “no link reinforcement”, the shear splitting is performed from the integral wall type pier at 1/200 to 1/100. It turns out that it moves to the behavior as two pillars, and asymptotically approaches the calculated value. On the other hand, according to FIG. 5 (b) showing the test value and the calculated value in the case of “with link reinforcement”, in the case of “with link reinforcement”, it behaves as an integrated wall type pier until a large deformation of 1/50. I understand that
[0016]
Second Embodiment of the Invention
The second embodiment of the present invention will be described below with reference to the drawings. In the second embodiment, a method for constructing a concrete structure in which interlocking bar arrangement can be easily performed by attaching an annular band 2 to a precast member in advance will be described. In addition, description is abbreviate | omitted about the content similar to Embodiment 1. FIG.
[0017]
<A> Half precast member The half precast member 5 is a member constructed in advance by embedding a part of the annular band 2. By precasting a part of the member, quality and work efficiency are improved, and by constructing the joint portion on site, the integrity as a structure can be ensured.
For example, the quadrangular prism-shaped half precast member 5 is manufactured by embedding the annular band 2 other than the overlapping portion in the concrete. Then, the annular band 2 exposed from the side surface of the quadrangular column is overlapped with the exposed annular band 2 of the other half precast member 5 disposed so as to face each other in a projected cross section. Between the half precast members 5 and 5, the concrete 7 is filled and integrated with each other to construct a columnar structure 4b (see FIG. 6A). Thus, interlocking bar arrangement can be easily performed by producing a part of concrete structure beforehand.
[0018]
<B> Precast formwork The precast formwork 6 is a formwork integrated with the concrete structure 4. For this reason, when the precast form 6 is used, the outer surface of the concrete structure 4 is formed by the precast form 6. In this precast form 6, the annular band 2 is arranged in advance. For example, when the precast mold 6 is manufactured, molds for manufacturing the precast mold 6 are arranged on both sides where the annular band 2 is installed, and the walls 61 and 61 of the precast mold 6 and the annular band Make concrete by filling concrete so that 2 is united. The precast mold 6a shown in FIGS. 6B and 6C is a precast mold 6a composed of two opposing wall portions 61, 61 and two rows of annular strips 2 disposed therebetween. The precast form 6b disposed on the wall can be manufactured by the wall portion 62 having a U-shaped cross section and the annular band 2.
FIG. 6B shows a wall-like structure 4c manufactured by arranging half precast members 5 and 5 at the end, precast molds 6a and 6a at the middle, and filling concrete 7 inside. .
FIG. 6 (c) shows pre-cast molds 6b and 6b having a U-shaped cross section at the end, pre-cast molds 6a, 6a and 6a at the middle, and concrete 7 is filled inside. It is the wall-shaped structure 4d manufactured in this way. Thus, by arranging the annular band 2 in the precast form 6 in advance, the interlocking bar arrangement can be easily performed.
[0019]
【The invention's effect】
Since the construction method of the concrete structure of the present invention is as described above, the following effects can be obtained.
<A> By using link bars, complicated bar arrangement work can be avoided. For this reason, even if the number of the annular band reinforcement arrange | positioned in the projected cross section increases, interlocking reinforcement arrangement | positioning can be performed.
<B> By using a precast member to which an annular band is attached, complicated bar arrangement work can be avoided. For this reason, even if the number of the annular band reinforcement arrange | positioned in the projected cross section increases, interlocking reinforcement arrangement | positioning can be performed.
<C> Since interlocking reinforcement can be easily performed even if the number of annular strips arranged on the projected cross section increases, interlocking reinforcement can also be applied to a concrete structure having a large aspect ratio.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an embodiment of a concrete structure with link bars according to the present invention. FIG. 2 is a side view of an embodiment of a concrete structure with link bars. FIG. 3 is an implementation of a hollow concrete structure. Cross-sectional view of example [FIG. 4] Relationship diagram showing relationship between shear force and displacement [FIG. 5] (a) Relationship diagram showing relationship between load and displacement in case of “without link reinforcement” (b) “Link reinforcement” FIG. 6A is a cross-sectional view of an embodiment of a concrete structure in which a half precast member is arranged. FIG. 6B is a diagram showing a half precast member and a precast formwork. Cross-sectional view of an embodiment of a concrete structure (c) Cross-sectional view of an embodiment of a concrete structure in which a precast formwork is arranged. FIG. 7 is a perspective view of an embodiment in which a conventional triple loop band is arranged. Example of conventional continuous band muscle group Perspective view DESCRIPTION OF SYMBOLS
DESCRIPTION OF SYMBOLS 1 ... Link reinforcement | strength 11 .... Main-body part 12 .... Leg part 2 ... Annular band 20 .... Annular band group 3 ... Main reinforcement 4 ... Concrete structure 5 ... Half precast member 6 ... Precast formwork

Claims (1)

In the method of constructing a concrete structure in which a part of the annular band surrounding the main reinforcement of the concrete structure is superposed on the projected section,
An annular band muscle group in which a part of the projected cross section is overlapped and an annular band muscle group in which a part of another projected section is overlapped are arranged without overlapping,
Both the main muscle that one annular band muscle group surrounds the link muscle composed of the main body part and the legs provided at both ends thereof, and the main muscle that the other annular band group surrounds , on the side part between both annular band muscle groups Arrange and connect so that
Filled with concrete to form a concrete structure with annulus rebars integrated ,
Construction method for concrete structures.

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