JP2011196089A - Hybrid cogging and column-beam joint structure using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide cogging for supporting a beam, which can obtain a shear force by a small cross section, which enables free arrangement of prestressing steel, and which prevents a deterioration in design by preventing exposure from a lateral surface of the beam.SOLUTION: The cogging 3 for supporting the beam, which is protrusively provided on a column 1 for supporting a precast concrete beam 2, includes a steel bracket portion 5, and a reinforced concrete overhang portion 4 which is integrally provided below the steel bracket portion 5. In a column-beam joint structure, the beam 2 is laid on the column 1 by engaging a recess 8 with the cogging 3; and the column and the beam are joined together by introducing prestress. The steel bracket portion 5 with high shear strength is used; the whole cogging 3 is formed in a small cross section; thus, the recess 8 formed on the side of the beam 2 is also formed in a small size; and the arrangement of the PC steel can be freely designed to suppress torsional moment generated by weight and a work load. Fall prevention and member stability at a construction stage are secured; and timbering and the like are not employed. Furthermore, the reinforced concrete overhang portion 4 dispenses with fire resistive covering of the steel bracket 5.

Description

  The present invention is a building structure constructed using a high-strength precast concrete member, a hybrid jaw having a high joint strength without damaging the appearance and a precast concrete excellent in earthquake resistance using the hybrid jaw. It relates to the joint structure of columns and beams.

  In general, in this type of column-beam joint structure, a PC crimp joint method according to the same applicant is known as a conventional example. For example, as a first conventional example, a large number of precast concrete columns are erected on a concrete foundation, and projections for receiving a large beam are integrally formed on the precast concrete columns. Beams and columns in a prestressed concrete structure in which a large number of large beams are installed between the columns while supporting the jaws of the part, and the precast concrete large beams are prestressed by PC steel wires and are fixed in tension to the precast concrete columns In the joint structure, a filler having a strength lower than the strength of the beam and the column is provided on the joint surface between the projection for receiving the beam of the precast concrete column and the jaw at the end of the precast concrete beam, and the PC steel wire is tensioned. (Patent Document 1).

  And, by providing a filler on the joint surface between the projection for receiving the beam of the precast concrete column and the jaw at the end of the precast concrete beam, the PC steel wire is tensioned to form a joint structure between the beam and the column. Energy absorption due to plastic deformation of the structure in the case is handled by the filler at the joint between the column and beam. The joint structure of the beam and the column can obtain performance exceeding the energy absorption of the RC structure. Even in the process from the beam end fixing to the hinge support, there is no risk of the large beam falling because it is supported by the projection for receiving the beam of the column. As the filler on the joint surface between the beam and the column cracks or breaks due to the earthquake, the earthquake vibration period of the structure becomes longer, so the impact force is reduced.

  In addition, as a second conventional example, a precast in which a joint end portion is placed on a beam receiving jaw of a precast concrete column that is erected on a foundation concrete at an appropriate interval and prestress is applied by a tension primary cable. A secondary cable for tension is installed between the precast concrete columns, and the tension cable is disposed along the length direction below the central portion of the precast concrete beam passing through the precast concrete columns and facing the precast concrete columns. The precast concrete beam is joined to the precast concrete column, and the joint ends placed opposite to the beam receiving jaw of the precast concrete column pass through the precast concrete column from one joint end to the other joint end. It is joined with the provided joining cable, and the joining cable is curved. And those having configurations wiring without being tensioned (Patent Document 2).

  With the above configuration, the tension secondary cable acts as a hinge in the event of a large earthquake, and the precast concrete beam is rotationally deformed around this to reduce the seismic energy. In addition, the expansion and contraction of the joining cable due to the rotational deformation of the precast concrete beam centering on the secondary cable for tension serves as a friction damper that absorbs repeated seismic energy and attenuates the seismic energy.

  Furthermore, as a third conventional example, a large number of columns are erected on a concrete foundation, and the beam receiving jaws projecting from the columns support the ends of the beams. The beam is prestressed by the PC steel wire and is fixed in tension to the column, and between the beam receiving jaw of the column and the end of the beam, the column and the beam are filled with stronger strength. It is set as the structure which provided the material (patent document 3).

  With the above configuration, when the prestressed concrete structure is subjected to repeated positive and negative loads due to a large earthquake, before the filler is destroyed, the edge between the filler and the beam breaks and acts as a hinge. Therefore, it can absorb seismic energy.

Japanese Patent Laid-Open No. 5-280092 JP 2007-92301 A JP-A-11-172762

  In the conventional example, in each of the connection between the column and the beam, the beam receiving jaw is projected and formed on the column, and the end of the beam is placed on and supported by the beam receiving jaw. The beam receiving jaw and beam end are exposed on both sides of the beam at the joint, and the filler between them is visible from both sides. Although measures against a large earthquake have been taken, there is a problem that it is not preferable in terms of design.

  Further, the beam receiving jaw is made of reinforced concrete, and a large cross-sectional area is required to support the weight of the beam, and a large number of reinforcing bars are arranged, so there is a restriction on the arrangement of the PC steel material. Normally, at the joint between the column and the beam, the PC steel material that tensions and fixes the beam from the two directions of the X axis and the Y axis in a plan view is arranged, and the PC steel material of the column is also arranged in the vertical (Z axis) direction. Therefore, there is a problem that the PC steel material in the beam cannot be freely arranged in the cross section of the beam.

  Therefore, the beam receiving jaw in the prior art can obtain a necessary shearing force with a small cross section, and can freely arrange the PC steel material and is designed as a building so as not to be exposed from the side surface of the beam. There is a problem to be solved in order not to impair the proper appearance.

  The present invention provides a beam receiving jaw protruding from a column for receiving a precast concrete beam, as a specific means for solving the problems of the above-described conventional example. The present invention provides a hybrid jaw comprising a steel bracket portion and a reinforced concrete overhang portion integrally provided at a lower portion thereof and integrally provided on a column.

  In the first aspect of the present invention, the beam receiving jaw includes an additional requirement that the width of the jaw is formed smaller than the width of the beam.

  According to a second aspect of the present invention, there is provided a beam receiving jaw including at least a steel bracket portion and a reinforced concrete projecting portion integrally provided at a lower portion thereof, and the beam receiving jaw. It is composed of a beam formed with a concave portion at the end, and the beam is built on the column by engaging the concave portion with the beam receiving jaw, and tension is applied to the PC steel material for prestress introduction between the two Thus, the present invention provides a beam-to-column joining structure characterized by being joined together.

  In this 2nd invention, it is included as an additional requirement that the column or beam is made of prestressed concrete.

  Since the first invention according to the present invention is a hybrid jaw composed of a steel bracket portion and a reinforced concrete overhang portion integrally provided at the lower portion of the beam receiving jaw protruding from the column, By using a steel bracket part with high shear strength, the entire beam receiving jaw can be formed in a small cross section, and the concave part formed on the beam side can also be formed small. Not only can it be designed freely, but also because the reinforced concrete overhang is formed, the beam is well-positioned (sitting) and stable when it is installed. It suppresses the torsional moment generated by the weight and working load of precast members as structures such as small beams and floor slabs, and prevents overturning against storms and small and medium earthquakes. Because of member stability is ensured, an excellent effect that members such as shoring can work without using.

  Further, the beam receiving jaw is formed so that the width of the jaw is smaller than the width of the beam, so that the problem of impairing the design appearance of the conventional jaw is solved without being exposed from the side surface of the beam. The

  Moreover, the joining structure which concerns on 2nd invention which concerns on this invention is the column which provided integrally the beam receiving jaw which consists of a steel bracket part and the reinforced concrete overhang | projection part integrally provided in the lower part. The beam receiving jaw is formed with a beam formed at its end to engage with the beam receiving jaw, the beam receiving jaw is engaged with the recess and a beam is installed on the column, and a prestress is introduced therebetween. By applying a column beam connection structure that applies tension to the PC steel material, the reinforced concrete overhanging part is twisted when subjected to horizontal forces such as wind and earthquake. It prevents twisting and buckling so that it does not buckle, and covers the steel bracket part, so that it does not require troublesome fireproof coating on the steel bracket and the beam receiving jaw is exposed on the side of the beam. And the appearance is better with the lower surface of the beam. Achieve the effect.

1 shows a basic joint structure of column beams using a hybrid jaw according to the first embodiment of the present invention, in which the columns (A) and beams (B) are separated and the joint surface side is shown respectively. It is a perspective view. It is the front view which shows the joining structure of the column beam which concerns on the embodiment, and showed the column (A), the beam (B), and the joining surface side, respectively. It is a side view which shows the joining structure of the state which joined the pillar and beam which concern on the embodiment. It is sectional drawing which follows the IV-IV line | wire of FIG. 3 in the joining structure of the state which joined the pillar and beam which concern on the embodiment. It is sectional drawing which follows the VV line | wire of FIG. 4 in the junction structure of the state which joined the pillar and beam which concern on the embodiment. It is a front view showing the basic joint structure of the column beam using the hybrid jaw according to the second embodiment of the present invention, showing the column (A), the beam (B), and the junction surface side. . It is sectional drawing similar to the said FIG. 5 in the junction structure of the state which joined the pillar and beam which concern on the embodiment. It is a front view showing a basic joint structure of a column beam using a hybrid jaw according to a third embodiment of the present invention, showing a column (A), a beam (B), and a junction surface side. . It is sectional drawing similar to the said FIG. 5 in the junction structure of the state which joined the pillar and beam which concern on the embodiment. It is the front view which showed the joint surface side of the column using the hybrid jaw which concerns on the 4th Embodiment of this invention.

  The present invention will be described in detail based on the illustrated embodiment. In the first embodiment shown in FIGS. 1 to 5, FIGS. 1 and 2 show a basic form, and in order to join the column 1 made of precast concrete and the beam 2, A hybrid jaw 3 as a beam receiving jaw is integrally formed on the side surface.

  The hybrid jaw 3 is composed of a reinforced concrete jaw portion (projecting portion) 4 which is integrally formed with the pillar 1 and a steel bracket portion 5 such as a plate provided in an upright state on the upper surface thereof. The steel bracket portion 5 is formed by integrally forming a base plate 6 on the lower surface side and a connecting plate 7 on the base portion side, and the base plate 6 is provided in a state of being embedded in the upper surface of the overhanging portion 4. The connecting plate 7 is attached in a state of being embedded in the pillar 1.

  Generally, since the beam 2 is attached to the column 1 at two or more locations, for example, a description will be given of the joining state of the column 1 and the beam 2 installed at the corner of the building. As shown, the beam 2 in a plurality of directions is attached to the column 1, and the hybrid jaw 3 as a beam receiving jaw is integrally formed on a plurality of surfaces to which the beam 2 is attached. And the base plate 6 which comprises the steel bracket part 5 is firmly attached to the overhang | projection part 4 by the some anchor material 6a which consists of stud bolts etc., for example, and is attached integrally, For example, the connection plate 7 is, for example, A plurality of anchor members 7a such as reinforcing bars are firmly connected to the column 1 and attached integrally.

  The beam 2 is provided with a concave portion 8 into which the hybrid jaw 3 is fitted at the lower surface side central portion of the end portion thereof. The recess 8 is formed in a similar shape substantially corresponding to the shape of the hybrid jaw 3, and a recess 8a in which the steel bracket portion 5 of the hybrid jaw 3 is fitted and a recess 8b in which the overhanging portion 4 is fitted. It consists of and.

  When the hybrid jaw 3 is fitted into the recess 8, a slight gap is generated on both sides of the fitting surface. That is, the height in the vertical direction of the concave portion 8 a into which the steel bracket portion 5 is fitted is made to coincide with the height of the steel bracket portion 5, but the width of the concave portion 8 a is larger than the thickness of the steel bracket portion 5. Slightly wide. Similarly, in the concave portion 8b into which the overhanging portion 4 is fitted, the vertical height of the concave portion 8b is matched with the vertical thickness of the overhanging portion 4, and the horizontal width of the concave portion 8b is determined by the overhanging portion. 4 is slightly wider than the width in the left-right direction.

  By forming the recesses 8 in this manner, the fitting operation of the hybrid jaw 3 can be easily performed when the beam 2 is attached to the column 1. A plurality of grout inlets 9 are provided in communication with the recesses 8 in order to fill these gaps generated after fitting with grout.

  Further, a plurality of sheath tubes 10 and 11 through which a PC steel material for tension fixing the beam 2 to the column 1 is inserted are provided on each of the column 1 side and the beam 2 side. In the case of this embodiment, the four sheath tubes 10, 11 in each direction in which the beam 2 is attached are in a state in which the positional relationship coincides when the hybrid jaw 3 and the recess 8 are fitted. When the directions are orthogonal to each other, they are shifted in the vertical direction as shown in the figure. In the figure, reference numeral 12 schematically shows a PC steel material.

  In the joining of the column 1 and the beam 2 configured as described above, the concave portion 8 of the beam 2 is fitted to the hybrid jaw 3 of the column 1 so as to be positioned at an almost appropriate joining position, as shown in FIG. In addition, the hybrid jaw 3 becomes invisible from the side, and the joint structure between the column 1 and the beam 2 is established in a state where the recess 8b is filled with the reinforced concrete overhanging portion 4. Thereafter, the PC steel material 12 is inserted into the sheath tubes 10 and 11, and a necessary grout 13 is injected from the grout inlet 9, and the hybrid jaw 3 and the recess 8 are formed as shown in FIGS. By filling the gap between them and hardening the PC steel 12 after the grout 13 is hardened, the column 1 and the beam 2 are firmly joined.

  In particular, the hybrid jaw 3 includes a steel bracket portion 5 and a reinforced concrete overhang portion 4 provided integrally therewith, and the steel bracket portion 5 is used as a member for supporting the load of the beam 2. By doing so, the necessary shear strength can be obtained with a small cross section, the size of the recess 8 provided at the end of the beam 2 can be reduced, and the arrangement of the PC steel material can be designed freely, as well as the column 1 and the beam 2 , The recess 8b is closed by the overhanging portion 4 so that the lower surface of the beam 2 is flush and the surrounding gap is filled by grout injection, so that the appearance is improved and the steel bracket portion 5 is This is because the fire-resistant coating of the steel frame is not necessary.

  In addition, since the hybrid jaw 3 is provided with a reinforced concrete overhanging portion 4, when the beam 2 is installed, the beam 2 is well placed (sitting) and stable. Sequentially placed on one side of the girder from one side can suppress the torsional moment caused by the weight and work load of precast members such as small beams and floorboards, as well as to prevent falling against storms and small and medium earthquakes that are received during construction. Since the stability of each component incorporated at the construction stage is ensured, no support work is required, and even after construction, steel is prone to torsion and buckling due to horizontal forces such as strong winds and earthquakes. It also serves to protect the bracket portion 5.

  Next, a second embodiment is shown in FIGS. 6 (A) and 6 (B) to FIG. The same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. The hybrid jaw 3 according to this embodiment is applied when the beam 2 to be installed is a long span and has a large load. The projecting portion 4 made of reinforced concrete that is integrally formed with the column 1 and its extension It consists of steel bracket portions 5a and 5b such as at least two plates provided in an upright state on the upper surface, and a large load is supported by the two steel bracket portions 5a and 5b. A steel base plate 6 is integrally provided on the lower surface side of the two steel bracket portions 5a and 5b, and a connecting plate 7 is integrally provided on the base side. 4 is provided in a state of being embedded in the upper surface of 4, and the connecting plate 7 is attached in a state of being embedded in the pillar 1.

  The base plate 6 provided on the lower surface side of the two steel bracket portions 5a and 5b is firmly attached to the overhanging portion 4 by a plurality of anchor members 6a made of, for example, stud bolts and attached integrally. The connection plate 7 is also connected to the column 1 by a plurality of similar anchor members 7a and is integrally attached, which is the same as in the first embodiment.

  Further, the beam 2 is provided with a recess 8 at the end of which the hybrid jaw 3 is fitted. The concave portion 8 is formed in a similar shape substantially corresponding to the shape of the hybrid jaw 3, and the concave portion 8a and the overhanging portion into which the two steel bracket portions 5a and 5b of the hybrid jaw 3 are fitted together. The point which is comprised from the recessed part 8b to which 4 fits, and the point which is made to communicate with the recessed part 8 and multiple grout inlets 9 are provided are the same as that of the said 1st Embodiment.

  Also in this embodiment, the concave jaw 8 of the beam 2 is fitted to the hybrid jaw 3 of the column 1 so that the hybrid jaw 3 can be seen from the side as shown in FIG. In other words, the lower surface of the beam 2 is flush with the lower surface of the beam 2, and the recess 8 b is closed by the reinforced concrete overhanging portion 4, thereby establishing a joint structure between the column 1 and the beam 2. Thereafter, the PC steel material 12 is inserted into the sheath tubes 10 and 11 and a necessary grout 13 is injected from the grout inlet 9 to fill a gap formed between the hybrid jaw 3 and the recess 8. The column 1 and the beam 2 are integrally joined by fixing the PC steel material 12 in tension after the 13 is hardened.

  Next, a third embodiment is shown in FIGS. 8A and 8B to FIG. Also in this embodiment, the same parts as those in the first embodiment or the second embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. The hybrid jaw 3 according to this embodiment includes a reinforced concrete projecting portion 4 that is integrally formed with the column 1 and a steel bracket portion 5c such as angle steel provided in an upright state on the upper surface thereof. A steel base plate 6 is integrally provided on the lower surface side of the steel bracket portion 5c of the angle steel, and a connecting plate 7 is integrally provided on the base side, and the base plate 6 has an overhang portion. 4 is provided in a state of being embedded in the upper surface of 4, and the connecting plate 7 is attached in a state of being embedded in the pillar 1.

  Then, the base plate 6 provided on the lower surface side of the angle bracket steel bracket portion 5c is integrally attached to the overhanging portion 4 by a plurality of anchor members 6a made of stud bolts, for example. The connection plate 7 is also connected to the pillar 1 by a plurality of similar anchor members 7a and attached integrally, as in the second embodiment.

  Further, as shown in FIG. 8 (B), the beam 2 is provided with a recess 8 in which the hybrid jaw 3 is fitted at the end thereof. The concave portion 8 is formed in a similar shape substantially corresponding to the shape of the hybrid jaw 3, and the concave portion 8a into which the angle bracket steel bracket portion 5c of the hybrid jaw 3 is fitted and the overhang portion 4 are fitted. It is the same as that of the said 1st and 2nd embodiment, but the point which is comprised from the recessed part 8b to perform, and the point provided with two or more grout injection | pouring ports 9 connected to the recessed part 8 are the only differences. Is that a steel reinforcing member 14 is provided inside a recess 8a into which the steel bracket portion 5c of the angle steel is fitted.

  In this way, by providing the reinforcing member 14 inside the concave portion 8a on the beam 2 side, in the case of a heavy load beam, it is possible to prevent cracks from occurring around the concave portion 8a due to contact with the steel bracket portion 5c. It can be done. Needless to say, the reinforcing member 14 can be applied to other embodiments. In short, the concave portion 8 provided at the end portion of the beam 2 is the reinforcing member 14 for preventing cracking so that the crack is not generated by the fitting contact with the hybrid jaw 3.

  Also in this embodiment, the concave jaw 8 of the beam 2 is fitted to the hybrid jaw 3 of the column 1 so that the hybrid jaw 3 can be seen from the side as shown in FIG. In other words, the lower surface of the beam 2 is flush with the lower surface of the beam 2, and the recess 8 b is closed by the reinforced concrete overhanging portion 4, thereby establishing a joint structure between the column 1 and the beam 2. Thereafter, the PC steel material 12 is inserted into the sheath tubes 10 and 11 and a necessary grout 13 is injected from the grout inlet 9 to fill a gap formed between the hybrid jaw 3 and the recess 8. The column 1 and the beam 2 are integrally joined by fixing the PC steel material 12 in tension after the 13 is hardened.

  Furthermore, the fourth embodiment shown in FIG. 10 will be described. This embodiment shows the hybrid jaw 3, and the same parts as those of the above-described embodiments are denoted by the same reference numerals, and detailed description thereof is omitted. The hybrid jaw 3 according to this embodiment includes a reinforced concrete overhanging portion 4 formed integrally with the column 1 and a steel bracket portion 5d such as channel shape steel or groove shape steel provided on the upper surface thereof. A steel base plate 6 is integrally provided on the lower surface side of the steel bracket portion 5d of the channel steel, and a connecting plate 7 is integrally provided on the base side. It is provided in a state of being embedded in the upper surface of the overhanging portion 4, and the connecting plate 7 is attached in a state of being embedded in the pillar 1.

  Although not shown, the base plate 6 provided on the lower surface side of the steel bracket portion 5d of the channel steel and the connecting plate 7 provided on the base side are respectively overhanged by a plurality of anchor materials as in the above embodiment. The hybrid jaw 3 is configured by being firmly connected to the portion 4 and the column 1 and integrally attached thereto. Although not shown, the end of the beam installed on the hybrid jaw 3 is provided with a recess substantially corresponding to the shape of the hybrid jaw 3 and a grout inlet, and the column 1. When the beam is erected, the overhanging portion 4 closes the recess and becomes flush with the lower surface of the beam, and the grout is injected to fill the gap between the recess and the steel bracket portion 5d. The point of inserting and fixing the tension is the same as in the above embodiment.

  In any of the embodiments, the fixing or fixing of the steel bracket portion constituting the hybrid jaw 3 to the pillar is a side surface facing the steel bracket without using a base plate, a connecting plate or an anchor material. It can be used to construct the opposite jaw hybrid jaws, or it can be thinned into a part extending inside the pillar so as not to hinder the placement of the PC steel material. . In short, the steel bracket portion only needs to obtain a shearing force sufficient to support the beam, and can be deformed into an arbitrary shape and configuration.

  In any case, the hybrid jaw 3 according to the above embodiment has a tough steel bracket portion that is rigid and excellent in impact resistance, and is excellent in pressure resistance and heat resistance provided integrally therewith. It is formed from a reinforced concrete overhang, and the overall strength is remarkably improved and the required shear strength is obtained with a small cross-sectional area, so that the strength as a member that supports the load of the beam 2 is sufficient. Accordingly, the size of the concave portion 8 provided at the end of the beam 2 can be reduced, and the arrangement of the PC steel material can be freely designed, and the lower portion of the concave portion 8 can be formed at the joint between the column 1 and the beam 2. Since the lower surface of the beam 2 is flush with the overhanging portion 4 and the surrounding gap in the fitting portion between the hybrid jaw 3 and the concave portion 8 is filled by grouting, the appearance is improved and the steel is made. Configure the bracket Fire protection of steel brackets which are become unnecessary.

  Further, since the hybrid jaw 3 is provided with a wide protruding portion 4 made of reinforced concrete, when the beam 2 is installed, the installation (sitting) of the beam 2 is good and stable. Later, it is possible not only to suppress the torsional moment caused by the weight and work load of precast members such as small beams and floorboards by sequentially placing them on one side from the other, but also toppling against storms and small and medium earthquakes received during construction. Since the stability of each member incorporated at the construction stage is secured, no support work is required, and even after construction, twisting and buckling occur due to horizontal forces such as strong winds and earthquakes. It also serves to protect the steel bracket, which is easy to protect.

  The hybrid jaw according to the present invention is excellent as a joint structure of precast concrete columns and beams, that is, as an anti-seismic or anti-vibration joint structure as a PC crimping method or a PC crimping joint method. It can be widely used not only for the construction of high-rise buildings such as, but also for other PC structures such as bridges.

1 Pillar 2 Beam 3 Hybrid jaw 4 Overhang 5, 5a, 5b, 5c, 5d Steel bracket 6 Base plate 6a, 7a Anchor material 7 Connection plate 8, 8a, 8b Recess
9 Grout inlet 10, 11 Sheath tube 12 PC steel 13 Grout 14 Reinforcing material

Claims (4)

A beam receiving jaw protruding from a column for receiving a precast concrete beam,
A hybrid jaw characterized in that the beam receiving jaw comprises a steel bracket portion and a reinforced concrete overhang portion integrally provided at a lower portion thereof, and is integrally provided on a column. The hybrid jaw according to claim 1, wherein the beam receiving jaw is formed so that a width of the jaw is smaller than a width of the beam. At least, a column provided integrally with a beam receiving jaw consisting of a steel bracket part and a reinforced concrete overhang part provided integrally therewith,
It is composed of a beam formed at the end with a recess into which the beam receiving jaw is fitted,
A beam-to-column connection structure characterized in that the recess is fitted to the beam receiving jaw, a beam is installed on the column, and a tension is applied to the PC steel material for introducing prestress between them. The column / beam connection structure according to claim 3, wherein the column or beam is made of prestressed concrete.

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