JP3942950B2 - Concrete block - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a concrete block used for reinforcing an existing column in a reinforced concrete building against an earthquake or the like.
[0002]
[Prior art]
Conventionally, as this type of concrete block, for example, one shown in FIG. 8 is known (Japanese Patent Publication No. 53-16214). As shown in FIG. 8 (B), the concrete block has a bottom surface 51a made of a rectangular plane, and an upper surface 51b made of a quarter arc surface of a circle having the bottom surface as a string and centering on the axis of an existing column. And a PC board 51 composed of two side surfaces 51c composed of crescent-shaped planes adjacent to the top and bottom of the bottom surface.
[0003]
As shown in FIG. 8 (A), reinforcement of the existing pillar is performed by adhering the PC plate 51 to the four circumferential surfaces of the existing pillar 52 made of reinforced concrete having a square cross section with a cement paste or the like over substantially the entire length. After the PC steel wire 53 is spirally wound and integrated with a certain tension, a surface finish 54 is applied to the entire circumference of the existing column 52 covered with the PC plate 51.
[0004]
[Problems to be solved by the invention]
It is stated that the above-mentioned reinforcing method of the existing column is to prevent the shear failure of the existing column 51 due to the repeated load applied by the earthquake by effectively restraining the core concrete.
However, in the above-described conventional method for reinforcing existing pillars, since the four circumferential surfaces of the existing pillars 52 are covered with an integral PC plate 51 over almost the entire length and the periphery thereof is tightened with the PC steel wire 53, the bending of the reinforcing pillars There is a problem that the rigidity becomes too large, and the deformability and energy absorption capability of the reinforcing column are lowered, and as a result, the earthquake resistance of the reinforcing column is not improved.
[0005]
In addition, since the PC steel wire 53 is wound around the PC plate 51 while applying a certain tension, it is necessary to pull the PC steel wire 53 in a tangential direction that constantly changes as the circular cross section of the reinforcing column is wound. There is also a problem that a device such as a hydraulic cylinder is indispensable because it is impossible by human power.
Furthermore, since the surface of the PC plate 51 is flat, the wound PC steel wire 53 may be displaced, and reinforcement may be incomplete, or mortar 4 must be applied to the entire periphery to prevent displacement. There is a problem that construction takes time and money.
[0006]
Therefore, an object of the present invention is to easily and inexpensively retrofit an existing column by devising a concrete block having a size and shape that can increase the shear strength while suppressing an increase in the bending rigidity of the reinforced column. It is to provide a concrete block that can.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the concrete block of the invention of claim 1 is provided with a bottom surface composed of a parallelogram plane, four side surfaces composed of a plane adjacent to the bottom surface, and opposed to the bottom surface. Ri Do of circularly arcuate surfaces contiguous in the concrete block with an upper surface forming a plurality of parallel grooves with each other, the bottom and top surface, forms a parallelogram in a projection view from the normal direction of the bottom surface, the parallelogram The distance between the leg of the perpendicular line extending from one end of the pair of sides in the direction intersecting the direction of the groove to the other side and one end of the other side is more than 1/4 of the pitch of the groove It is small .
[0008]
Unlike the PC board described in the conventional example of FIG. 8B, the above concrete block is a side surface in which both ends in the arc direction (left and right direction) of the arc surface of the upper surface facing the bottom surface formed of a parallelogram plane are flat surfaces. It has become. Therefore, when this concrete block is attached to each peripheral surface of an existing column having a regular polygonal cross section with, for example, cement paste, a gap is formed between the side surfaces facing each other at each corner of the regular polygon. In addition, if the length of the side surface in the plan view of the concrete block is shortened, preferably shorter than the length of one side of the existing column, a plurality of concrete blocks are stacked to cover the entire length of each peripheral surface of the existing column, A circumferential gap is created in the stack. And a steel wire is wound around several parallel groove | channels of the outer peripheral surface of this concrete block.
These grooves, for example, extend in parallel with the upper and lower sides of the parallelogram in the plan view, so that when these grooves make a round in the circumferential direction through the gaps at the respective corners of the existing columns, for example, one pitch is advanced. In addition, if concrete blocks are sequentially attached in a spiral manner to each peripheral surface of an existing pillar having a regular polygonal cross section, a steel wire that has been processed into a spiral shape with a diameter slightly smaller than the diameter of the spiral groove in advance is applied with a small force. For example, it can be easily wound around the groove even by human power, and the wound steel wire does not slip without applying mortar to the surface as in the conventional example, and the concrete block is firmly integrated with the existing pillar. To greatly improve the shear strength of existing columns. Therefore, it is possible to reinforce the existing pillars by increasing the shear strength against repeated horizontal loads caused by earthquakes, and to greatly reduce the labor and cost required for reinforcement.
The existing columns reinforced with concrete blocks around the entire circumference change the gap when subjected to an earthquake load, so the shear strength is increased without increasing the bending rigidity against the earthquake load compared to the conventional example, The ability to absorb seismic energy can be increased. That is, according to the concrete block and the steel wire, it is possible to firmly reinforce the existing column against repeated horizontal loads caused by earthquakes. Further, in the conventional example of FIG. 8B, when pasted around the entire circumference of the existing pillar as shown in FIG. 8A, the adjacent concrete blocks contact each other without a gap, and the contact points are existing due to an earthquake. There is a possibility that the pillar will be broken off due to the deformation of the column, but there is no such a fear in the concrete block of the present invention.
[0009]
[0010]
[0011]
[0012]
[0013]
[0014]
Further, in the concrete block, the distance between the leg of the parallelogram in the plan view, for example, from the upper end of the right side to the left side, and the upper end of the left side is smaller than 1/4 of the groove pitch. Specifically, it corresponds to a pitch corresponding to the height of the side surface forming the left and right sides in the plan view, that is, one of the gaps formed at the four corners of the existing pillar having a square section, rather than 1/4 of the groove pitch. Only the pitch is small. Thus, if we turn affixed to concrete block spirally four sides surfaces of the existing columns of square cross-section, the groove is smoothly continuous with the spiral through the four corners of the gap, in the above the same way in the groove, A steel wire that has been processed in a spiral shape can be easily wound manually, and the steel wire is not displaced even if the surface is not finished as in the conventional example, and the concrete block is firmly integrated with the existing column.
[0015]
Na us, the distance from the top of the parallelogram of the right side and perpendicular foot and the left side of the upper end drawn down to the left side in the plan view of concrete block, 1 / n of the pitch of the grooves (n: 3 or more integer) If it does so, the same seismic reinforcement as the above-mentioned can be performed about the existing pillar which has a regular n square cross section.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments. FIG. 1 is a perspective view showing an example of a concrete block used to reinforce an existing pillar. FIGS. 2A to 2E are a plan view, an upper side view, and a bottom view, respectively, of the concrete block of FIG. It is a side view, a right side view, and a left side view.
The concrete block 1 has a bottom surface 11 formed of a parallelogram plane as shown in FIG. 2 (A) and a plane adjacent to the bottom surface 11 as shown in FIGS. 2 (B) and 2 (C). 4 sides consisting of upper and lower sides 12a, 12b and left and right sides 13a, 13b which are basically rectangular as shown in FIGS. And an upper surface 14 formed of an arc surface connected to the opposed left and right side surfaces 13a and 13b.
On the upper surface 14 of the concrete block 1, the upper and lower side surfaces 12a and 12b are formed in the plan view of FIG. 2A, and a plurality of arc-shaped grooves 15 as shown in FIG. Is forming. In FIG. 1, the broken line indicates the bottom of the groove 15, and the solid line between the broken lines indicates a mountain between adjacent grooves.
[0017]
3 and 4 are a longitudinal sectional view and a plan view showing a state in which the concrete block 1 is reinforced by being attached to the four circumferential surfaces of the existing pillar 20 having a square section. In the concrete block 1, the width of the left and right side surfaces 13 a and 13 b is smaller than the width of the existing column 20, and the height of the upper and lower side surfaces 12 a and 12 b is also lower than the width of the existing column 20. The concrete block is concrete that has been stuck in the circumferential direction while the bottom surface 11 is bonded to the lower peripheral surface 21 of the existing pillar 20 with cement paste, and then pasted through the spacing 22 filled with the poor blending mortar 23 and the like. In addition to being stacked on the block, the outer periphery of the existing pillar 20 is spirally covered upward from the base portion 20a by being sequentially attached to the peripheral surface 21 of the existing pillar 20 in the circumferential direction. However, the upper and lower ends of the existing column 20 are not covered with the concrete block 1 so that the flexural rigidity of the reinforcing column can be suppressed and can be flexibly flexed by an earthquake load (see FIG. 3).
The member sandwiched between the upper and lower concrete blocks is not limited to the poor blending mortar 23, and a material such as a wooden plug or rubber that is damaged and opened by a predetermined seismic load can be used.
[0018]
As shown in FIG. 4, when the concrete block 1 covers the existing column 20, the circular arc surface 14 as the upper surface forms a cylindrical surface with a constant radius centered on the axis C of the existing column, Since both ends are cut off to become the left and right side surfaces 13a and 13b, a gap 22 is formed on both sides of the corner of the existing column 20 where the peripheral surface 21 of the existing column is exposed. The existence of this gap allows the degree of damage to the existing columns to be observed directly from the gap after the seismic load is applied.
A plurality of grooves 15 provided on the upper surface 14 of the concrete block 1 in parallel with the upper and lower side surfaces 12a and 12b are parallel to each other. When the concrete block covers the four circumferential surfaces of the existing columns as shown in FIG. Through the gap, the groove 15 of the concrete block adjacent in the circumferential direction is smoothly spirally connected.
[0019]
FIG. 5 is a developed view showing the groove 15 of the concrete block 1 covering the four peripheral surfaces 21 of the existing pillar 20 and the spiral steel wire 24 fitted into the groove and wound.
As shown at the left end of FIG. 5, the groove 15 is formed by forming a sinusoidal concave portion on the upper surface 14 of the concrete block 1 and starting from the lower end of the concrete block pasted on the lower portion of the first peripheral surface 21 a. After making a round of the existing pillar, the concrete block of the peripheral surface 21a is again connected to the grooves 15 of the three concrete blocks attached to the peripheral surfaces 21b, 21c, 21d on the right side sequentially through the gaps 22 at the corners of the columns 20. It is connected to the uppermost groove (showing a part overlapping with the right end in FIG. 5), and this is repeated to reach the upper end of the existing pillar. A steel wire 24 is wound around the spiral groove 15 as shown in the figure.
[0020]
The upper and lower side surfaces 12a and 12b of the concrete block 1 shown as the upper and lower sides of the parallelogram in FIG. 5 and thus the grooves 15 extending in parallel therewith are the four peripheral surfaces 21a of the existing columns as can be seen from FIG. When one round of .about.21d is made, it is raised by a distance of 1 pitch p of the groove 15. Speaking of one groove 15 (for example, the lower end of the peripheral surface 21a) crossing the concrete block 1, the ascending distance of the groove rises from p / 4 corresponding to 1/4 of the existing column to the interval corresponding to the column angle. The value is obtained by subtracting α from α (p / 4−α). Therefore, the slopes of the upper and lower surfaces 12a and 12b of the concrete block 1 are also the left and right sides of the parallelogram as shown in FIG. The slope is such that the distance between the foot of the perpendicular line extending from the lower end of the left side 13a to the right side 13b and the lower end of the right side 13b is (p / 4-α). The increase α corresponding to the gap interval refers to an increase distance when the groove 15 advances with the same inclination as that in the concrete block 1 through the gap with the column angle in FIG. 4.
[0021]
The steel wire 24 wound around the groove 15 is different from the conventional straight wire of FIG. 8 in that the diameter is smaller than the diameter of the groove 15 that goes around the existing column 20 (preferably the diagonal line of the existing column cross section is the diameter). It is processed in advance into a spiral bundle having a diameter of 80% of the diameter to be wound, and is manually wound without using a tension machine such as a hydraulic cylinder. The method of winding the steel wire 24 bundled in a spiral manner around the existing pillar is described in detail in Japanese Patent No. 3190556 belonging to the applicant of the present application, and will be briefly described here.
[0022]
That is, the steel wire 24 processed into a spiral bundle is arranged vertically so that the loop surface of the bundle is parallel to the peripheral surface of the existing pillar, and is bent at a right angle to start winding (see FIG. 5). Is inserted and fixed in a hole (not shown) provided at the lower end of the peripheral surface 21a, is rotated around the existing pillar while rotating in a direction to unwind the bundle of steel wires, and wound around the existing pillar one loop at a time. Then, the steel wire 24 is fitted into the spiral groove 15 and is wound around upward. Finally, the end 24b (see FIG. 4) bent at a right angle is inserted into a hole provided at the upper end of the peripheral surface and fixed to complete the winding. The fixing method of the steel wire end portion may not be fixed to the peripheral surface of the existing column, but the steel wire may be overlapped with the outer periphery of the concrete block and wound to fix the overlapped portion with a clip.
This method does not bend the spiral bundle of steel wires in the loop plane in the direction of unwinding the loop, but rather open the steel wire around its axis while circulating the spiral bundle of steel wires around the existing column. Since it can be wound in an elastic deformation range that can be slightly twisted, it can be easily and quickly constructed with only human power without requiring a large-scale machine such as the hydraulic cylinder described in the conventional example of FIG. . The steel wire may be a steel bar or a stranded wire.
[0023]
Next, a method for reinforcing the existing pillar 20 using the concrete block 1 of the above embodiment will be described.
First, on the lower end outer periphery of the base portion 20a of the existing column 20, together with the paint poor mixing mortar 23 in a predetermined thickness, the cement paste to at least one of four circumferential surface 21 or concrete block 1 in the bottom surface 11 of the existing pillar 20 After coating, the bottom surface 11 is brought into contact with each peripheral surface 21 while the lower surface 12 b of the concrete block 1 is placed on the poor blending mortar 23, and the four concrete blocks 1 are attached to the outer periphery of the existing pillar 20. Next, a spacing portion 22 having a thickness of 1 to 2 cm filled with poor blending mortar 23 is provided on the upper side of each pasted concrete block, and the four concrete blocks 1 are stacked on the peripheral surface 21 in the same manner. To go. Here, as shown in FIG. 5, the concrete block 1 is a parallelogram in which the left, right side, top, and bottom sides are not orthogonal to each other, so the top surface of the poor blending mortar 23 and the poor blending mortar 23 between the upper and lower blocks are filled. The spaced apart portion 22 is inclined with respect to the horizontal plane.
[0024]
When the concrete block 1 has been pasted over the entire length of the four circumferential surfaces of the existing pillar 20, it is pre-processed into a spiral bundle having a diameter slightly smaller than the diameter of the spiral groove 15 of the concrete block that goes around the existing pillar once. The steel wire 24 is fitted into the spiral groove 15 by the manual method described above, and the winding over the entire concrete block is completed. This steel wire winding method does not require a large-scale machine such as a hydraulic cylinder as described above, and has a great advantage that it can be easily and quickly constructed by human power alone.
Note that the upper and lower ends of the existing columns are not covered with the concrete block 1 because the bending rigidity already described is not excessive. Moreover, since the wound steel wire 24 is closely fitted in the groove 15 and does not shift, it is not necessary to apply mortar to the entire surface of the steel wire as in the conventional example of FIG. As shown in FIGS. 4 and 5, the start end 24 a and the end end 24 b of the steel wire 24 are inserted and fixed in holes provided in the peripheral surface of the existing pillar, but instead of this, the steel wires are bound together. It may be tied and fixed.
[0025]
The existing columns 20 shown in FIGS. 3 and 4 reinforced in this way behave as follows during an earthquake and effectively absorb the vibration energy of the earthquake.
The existing pillar 20 is not a long and integral four PC plates 51 attached to the four peripheral surfaces as in the conventional example described in FIG. 23 and a fragile material such as a wooden plug, etc. are stacked and pasted to be reinforced to create a gap in which the peripheral surface of the corner of the existing pillar 20 is exposed. Therefore, when a bending load due to an earthquake is applied, the existing pillar 20 is opened as the poor mortar 23 in the stacked portion of the blocks breaks down and is deformed as shown in FIG. 6 before the excessive bending load is applied. That is, unlike the conventional example of FIG. 8, the reinforcing column of the present embodiment does not have excessive bending rigidity and does not deteriorate the deformability and energy absorption capability, resulting in improved earthquake resistance. Further, the concrete blocks adjacent in the circumferential direction do not come into contact with each other by the gap 22, so that the contact points do not collide with each other due to the deformation of the existing columns due to the earthquake and fall off.
[0026]
Since the existing pillar 20 is wound by expanding the diameter of the steel wire 24 that has been processed in a spiral shape slightly smaller than the diameter of the spiral groove 15 while slightly twisting it, without using a hydraulic cylinder or the like. The steel wire 24 is brought into close contact with the concrete block 1 with an elastic force, and the wound steel wire 24 greatly improves the shear strength of the existing column 20. That is, the reinforcing column according to the present embodiment increases the shear strength without increasing the bending rigidity. As a result, the toughness is improved, and the existing column 20 is strengthened by effectively absorbing the seismic energy. It can be reinforced.
[0027]
FIG. 7 is a cross-sectional view showing another embodiment of the concrete block of the present invention.
The concrete block 31 reinforces the existing column 20 having the same square cross section as that in FIG. 4, but the radius of curvature of the arc surface of the upper surface 34 is larger than the radius of curvature of the arc surface 14 circumscribing the existing column in FIG. Only the big point is different.
The reinforcement method of the existing pillar using the concrete block 31 of this embodiment is essentially the same as the method described in the previous embodiment, and although the description is omitted, the same operations and effects are achieved.
[0028]
In the said embodiment, the case where the upper and lower side surfaces 12a and 12b which are the upper and lower sides of a parallelogram in the top view of the concrete block 1 in FIG. 2 was not orthogonally crossed with the right and left side surfaces 13a and 13b which were right and left sides was described. However, according to the present invention, as long as the plurality of arc-shaped grooves 15 are provided so as to form a part of the spiral, a parallelogram in which the upper and lower side surfaces and the left and right side surfaces are orthogonal, In the figure, it can be applied to a rectangular concrete block, and the same operation and effect can be achieved.
[0029]
Further, the inclination of the groove 15 is such that, for the concrete block 1 used for the existing pillar 20 having a square cross section, the pitch α corresponding to one of the gaps at the four corners with respect to the horizontal distance is ¼ of the groove pitch p. However, if the pitch corresponding to one of the gaps at the n corner is smaller than 1 / n of the groove pitch p, the existing pillar having a regular n-gonal cross section is surrounded in a spiral shape. it can. The groove 15 in the above embodiment is a single groove that advances one pitch in one turn, but can also be a two groove groove that advances two pitches in one turn, and the cross-sectional shape of the groove is also the sine wave shape of the embodiment. For example, the cross-sectional shape of the groove may be trapezoidal.
[0030]
Furthermore, the concrete block of the present invention can be changed to an existing column having an n-square cross section with a rectangular cross section or an uneven length of each side by changing the circumferential width and the radius of curvature of the arc surface so as to match the existing column cross sectional shape. Can be applied, and the same operations and effects as described in the above-described embodiment can be obtained.
[0031]
【The invention's effect】
As is apparent from the above description, the concrete block according to claim 1 of the present invention is the dimension between the arc-direction ends of the arc surface having a plurality of parallel grooves on the upper surface facing the bottom surface consisting of a parallelogram plane. There Yes shorter than one side of the existing columns, and since has become a side consisting of a plane, said plurality of grooves is advanced through the gap encircling continuous to the circumferential direction when for example one pitch of each corner of the existing columns Thus, if the concrete block is attached in a spiral manner to each peripheral surface of the existing pillar having a regular polygonal cross section, a steel wire that has been processed into a spiral shape with a diameter slightly smaller than the diameter of the spiral groove in advance, The steel wire can be easily wound around the groove with a small amount of human power, and the concrete block is firmly integrated into the existing column without slipping without applying mortar to the surface as in the conventional example. Te, can greatly improve the shear strength of the existing column, and it is possible to greatly reduce the labor and expense required for reinforcement. In addition, the reinforcing column changes when the gap is broken during bending deformation. Therefore, the shear strength is increased and the seismic energy absorption capacity is increased without increasing the bending rigidity against the seismic load as in the conventional example. The existing columns can be strongly reinforced against repeated loads caused by earthquakes, and the gaps between the concrete blocks adjacent to each other in the circumferential direction can prevent the blocks from colliding and falling off.
[0032]
[0033]
[0034]
Further, in the concrete block, the distance between the leg of the parallelogram in the plan view, for example, from the upper end of the right side to the left side, and the upper end of the left side is smaller than 1/4 of the groove pitch. Thus, if we turn affixed helically concrete blocks on four sides surfaces of the existing columns of square cross-section, Runode Tsurana smoothly spiral the grooves through the four corners of the gap, the groove, pre spiral Ru can be wound the processed steel wire to more easily.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an embodiment of a concrete block of the present invention used for reinforcing an existing pillar.
FIG. 2 is a bottom view, a top and bottom side view, and a left and right side view of the concrete block.
FIG. 3 is a longitudinal sectional view of an existing column reinforced with the concrete block of FIG. 1;
4 is a plan view of the existing pillar in FIG. 3. FIG.
FIG. 5 is a development view of a groove of the concrete block of FIGS. 3 and 4 and a spiral steel wire wound around the groove.
FIG. 6 is a front view showing a state of deformation of the existing pillar due to an earthquake load.
FIG. 7 is a plan view showing another embodiment of the concrete block of the present invention.
FIG. 8 is a perspective view showing a conventional method of reinforcing an existing column with a PC plate.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1,31 Concrete block 11 Bottom surface 12a, 12b Top, lower surface 13a, 13b Left, right side surface 14, 34 Upper surface 15 Groove 20 Existing column 21 Peripheral surface 22 Spacing part 23 Poor compounding mortar 24,35 Steel wire

Claims (1)

A bottom surface comprising a parallelogram plane, and four side surfaces consisting of planes adjacent to the bottom surface, while facing the bottom surface, Ri Do from arcuate surface leading to the side, to form a plurality of parallel grooves with each other top In a concrete block with
The bottom surface and the top surface form a parallelogram in a projection from the normal direction of the bottom surface, and a perpendicular line extending from one end of one of a pair of sides in a direction intersecting the direction of the groove of the parallelogram to the other side. A concrete block characterized in that the distance between the leg and one end of the other side is smaller than 1/4 of the pitch of the groove .

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