JPH09296565A - Precast concrete column, its manufacture, and execution method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the execution property by making split faces of a column which is split into an upper column body and a lower column block coincide with each other and arranging the column perpendicular with reference to the lower column block. SOLUTION: A PC column is split into an upper column body 2 provided with a corbel for connecting beams and a short lower column block 3, and split faces are correctly made to coincide with each other in connection. During the execution, the block 3 is fixed perpendicular on a bed mortar 13 which is placed on an upper surface of a concrete foundation 11, and an upper end of a PC bar 12 embedded in the foundation 11 is passed through the block 3. After the mortar 13 is hardened, the column body 2 is erected thereon through a temporary receiving base block 14 by a crane to connect a lower end of a PC bar 15 inserted in the column body 2 in advance to the upper end of the bar 12. The base block 14 is removed, the adhesive is applied to the block 3 to lower the column body 2, and the bar 15 is temporarily fixed to erect the column body 2 perpendicular by itself, and then, the bar is permanently tightened. Perpendicularity can be secured without using any support wire.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a precast concrete column (hereinafter referred to as a PC column) used in the construction of a multi-storey floor structure, a structure of a PC column standing on a concrete foundation, and a structure of the PC column. The present invention relates to a manufacturing method and a construction method using the PC pillar.

[0002]

2. Description of the Related Art Conventionally, various construction methods have been developed in which a PC column is erected on a foundation and a precast concrete beam is rigidly connected to this to construct a multi-story structure. In general,
In most cases, the conventional method of erection of PC columns is P
The C pillar is erected on the existing cast-in-place concrete foundation.

As an example of a conventional example, as shown in FIG. 6, a pillar burying hole b is formed on the upper surface of a cast-in-place concrete foundation a.
Is opened, the lower end of the PC pillar c is inserted into the pillar embedding hole b to stand upright, and the PC pillar c and the pillar embedding hole b are An arrow e is driven into the gap to temporarily fix it, and a filler f such as mortar or concrete is filled in the gap between the PC column and the column embedding hole b, and when the filler is hardened, the PC column c and the concrete foundation. The PC pillar c is made independent by integrating with a.

As another example, as shown in FIG.
One end side of the PC steel bar g is embedded and fixed in the cast-in-place concrete foundation a and the other end is cast-in-place concrete foundation a.
The PC steel rod h is inserted in the PC pillar c in the longitudinal direction, and the lower end thereof is made to protrude into the recess j of the lower end surface of the PC pillar c. It stands on the upper surface of the foundation a through the mortar k, the verticality is adjusted by the supporting wire d, and the PC steel bar g on the side of the foundation a and the PC steel bar h on the side of the PC column c are coupled in the recess j. m to connect, and the PC steel bar h is tensioned and fixed to the upper end of the P column c,
A vertical pre-stress is introduced into the C pillar c to make it self-sustaining, and the recessed portion j is filled with post-cast mortar.

[0005]

In the conventional construction method as described above, the verticality is corrected by adjusting the lengths of the supporting wires around the PC pillars, but many building layers are used. In this case, the weight of the PC column increases, it is difficult to correct the verticality, and the construction time becomes long, which is inefficient. In addition, the long diagonal support wires stretched around the PC pillar during this period hinder other work and deteriorate the work environment.

Further, in the construction method for providing the pillar burying hole described above, it is necessary to increase the strength of the basic concrete around the pillar burying hole. However, it was difficult to secure the horizontality of the bottom of the hole because the pillar burial hole was deep.

Further, in the method using the above-mentioned PC steel rod, the work of tensioning the PC steel rod is required at the top of the PC pillar stretched around the supporting wire before the self-supporting in the field, and the work risk is high, and Since it is necessary to provide a concave portion serving as a working space for connecting the PC steel rods at the lower end portion of the PC column, there is a problem that it is necessary to increase the cross section of the PC column in order to compensate for this. .

Therefore, in the conventional example, the self-standing P
There are problems that must be solved in order to simplify the correction of the verticality of the C pillar both in terms of work and structure and to improve the work environment and improve workability.

[0009]

As a concrete means for solving the above-mentioned problems of the conventional example, the present invention firstly forms a precast concrete column by dividing it into an upper column body and a lower column block, It is to provide a precast concrete column characterized in that the dividing surfaces are aligned so as to form one vertical column when the upper column body and the lower column block are connected. The upper pillar and the lower pillar block each have a structure in which a sheath into which at least PC steel is inserted is embedded, and the upper pillar includes a precast concrete pillar integrally formed with a corbel. It includes.

Secondly, the precast concrete is characterized in that a predetermined dividing means is provided in the integral formwork for molding the precast concrete column, and the upper column body and the lower column block are simultaneously molded in the divided state. A method for manufacturing a pillar is provided. Further, the dividing means includes a plate material or a sheet material, and a method of setting a sheath into which a PC steel material is inserted and setting concrete at a predetermined position in the mold.

Thirdly, a precast concrete column is continuously connected to a pre-constructed cast-in-place concrete foundation to form a PC.
A method for standing a precast concrete column in which steel materials are connected and the PC steel material is tensioned to integrate an existing cast-in-place concrete foundation and a precast concrete column, wherein the precast concrete column is an upper column whose mating surfaces match. Use the one divided into the body and the lower pillar block, and install it on the cast-in-place concrete foundation with the vertical plane of the lower pillar block as the reference, and install the divided surface of the upper pillar body on the lower pillar block. Then, the construction method of the precast concrete column is characterized in that the PC steel rod of the upper column body is connected to the PC steel rod of the lower column block to give a predetermined tension force. Further, it also includes a construction method in which the upper precast concrete columns are sequentially connected and erected on the lower column block and the upper column body installed on the cast-in-place concrete foundation.

In the PC pillar according to the present invention, the upper pillar body and the lower pillar block are divided, and the divided surfaces are formed so as to coincide with each other. The pillar block is first installed on the top surface of the cast-in-place concrete foundation, and at the time of installation, the exact building position and verticality can be easily adjusted. The workability is further simplified because the upper column is simply added.

Further, when the upper pillar body and the lower pillar block are divided, they can be formed as one pillar by interposing a dividing means such as a partition plate in the form, so that the dividing surfaces are completely coincident with each other. It can be formed efficiently in this state.

Further, when the PC pillar of the present invention is used for construction, a lightweight lower pillar block can be installed on the upper surface of the concrete foundation with accurate verticality through the mortar and the supporting wire can be installed. Since it is not necessary to stretch all four around, it does not deteriorate the working environment,
After the floor mortar has dried, the vertical pillar can be automatically provided by directly mounting the upper pillar body on the lower pillar block, so that the PC pillar can be easily self-supporting.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail with reference to the illustrated embodiments. First, FIG. 1 shows a precast concrete column according to the present invention, that is, a PC column 1. The PC column 1 is divided into an upper column body 2 and a lower column block 3.

In this case, the divided surfaces of the upper columnar body 2 and the lower columnar block 3 are exactly the same when they are connected to each other so that the entire column is vertical without any distortion. Has been formed. In other words, since one PC pillar 1 is divided into upper and lower parts, the divided surfaces are the same, and if the two are abutted, the divided surfaces fit perfectly and can be restored to the original column without distortion. It makes sense.

The division ratio between the upper pillar 2 and the lower pillar block 3 is about 10: 0.3 to 1, and the lower pillar block 3 is relatively short in consideration of workability and easiness of handling. Has been formed. A corbel 4 for mounting and connecting a beam is formed on the upper column 2. The corbels 4 are formed in at least two directions, although the number thereof varies depending on the use part of the PC pillar 1.

In the upper column body 2 and the lower column block 3, required rebars are embedded, and a plurality of sheaths for inserting a PC steel rod to which prestress is inserted are embedded. Each end of the column block is exposed at the upper and lower ends of each column block.

When the PC pillar 1 is manufactured, as shown in FIG. 2, it is manufactured by using a predetermined mold 5. In this case, a partition plate 6 as a dividing means is interposed at a predetermined position on the lower side of the PC column 1, and necessary metal fittings, reinforcing bars, sheaths, etc. are inserted and concrete is poured. In addition, 7 is a forming part of the corbel 4.

In this case, the predetermined position is, for example, a position of about 30 to 50 cm from the end side forming the lower end side of the PC pillar, and is a position serving as a dividing surface between the upper pillar body 2 and the lower pillar block 3. It is determined according to the length of the PC pillar 1, but if the lower pillar block 3 is too short, it is difficult to obtain the verticality at the time of construction, and if it is too long, the weight becomes heavy and it is inconvenient to handle at the time of construction. is there. Therefore, the length should be set within a range that does not cause any inconvenience in handling and verticality.

After the curing of the concrete cast in the mold 5 is completed, the upper pillar 2 and the lower pillar block 3 are released from the mold 5 and separated. However, the upper and lower pillar blocks formed together by one formwork are treated as one pillar body even if tired, and in principle, they cannot be replaced with those formed by other formwork.

Instead of inserting a partition plate 6 as a dividing means, a sheet-like partition may be inserted, or a single PC pillar 1 may be cut with a concrete cutter or water jet to separate the lower pillar block 3. The same structure can be obtained by forming them. In any case, the PC column 1 is formed by excluding the partition plate and other division allowances in advance.
Of course, it is necessary to accurately set the length dimension of and to set the size and the like of the formwork 5.

The PC pillar 1 of the present invention thus formed
Construction using will be described with reference to FIGS. First, as shown in FIG. 3, at a construction site, for example, a cast-in-place concrete foundation 11 is constructed on a foundation pile 10, and an upper surface portion 11a thereof is constructed with a predetermined levelness.

When constructing the concrete foundation 11,
A plurality of PC steel rods 12 are aligned and embedded in the concrete foundation 11 in a vertical direction, and an upper end portion of the PC steel rods 12 is projected from the upper surface of the concrete foundation 11 by a predetermined length.

The upper surface portion 11 of this concrete foundation 11
The floor mortar 13 is laid on the surface a and spread to a predetermined thickness, and the lower pillar block 3 is placed on the floor mortar 13 and adjusted so as to be horizontal or vertical. In this case, as shown in FIG. 4, the PC steel rods 12 protruding from the upper surface of the concrete foundation 11 are respectively inserted into the corresponding sheaths 3a arranged in the lower column block 3 to install the lower column block 3. To do.

Then, the level and verticality of the installed state of the lower pillar block 3 are accurately and sufficiently adjusted on the floor mortar 13 and allowed to stand, and the curing of the floor mortar 13 is waited. After observing a predetermined strength after the floor mortar 13 is hardened, a temporary receiving base 14 is placed on the upper surface of the mortar 13 at the center and the upper column 2 is erected using a heavy machine such as a crane.

The upper column 2 has a plurality of other PC steel rods 1
The holes 5 are formed by the sheath 2a, and the lower end of the hole is expanded by the coupler sheath 2b so that the long nut 16 shown in FIG. 5 can be accommodated. The PC
The steel rod 15 with a nut and a washer is previously inserted into the upper columnar body 2, and when the upper columnar body 2 is placed on the temporary receiving base 14 and stood upright, the PC steel rod 15 is attached to the upper columnar body 2. It is designed to project from the lower portion for a predetermined length.

In this state, the long nut 16 is screwed into the upper end of the PC steel rod 12 inserted through the lower column block 3, and the lower half of the long nut 16 is screwed. And long nut 1
The upper half of 6 is screwed to the lower ends of the other PC steel rods 15 protruding from the lower end of the upper columnar body 2, and the corresponding P
C steel rods are connected in series.

Then, the corresponding PC steel rod 1 of the upper column 2
After all the connection between 5 and the PC steel rod 12 of the lower pillar block 3 is completed, a heavy machine such as a crane that suspends the upper pillar body 2 is driven to slightly lift the upper pillar body 2 and the temporary receiving base 14
After removing, the adhesive is applied to the upper surface of the lower pillar block 3, the heavy equipment such as a crane is driven to vertically lower the upper pillar body 2, and the dividing surface with the lower pillar block 3 is joined. Form a single PC column 1 in close agreement with each other, and each PC steel rod 15 is hypothetically attached to the upper part of the upper column 2 with a tension force enough to make the upper column 2 self-supporting. By this hypothetical attachment, each upper column 2 can be self-supported as designed in an appropriate state without the need for a supporting wire.

The upper pillar body 2 and the lower pillar block 3 which are self-supporting as described above, become self-supporting as a whole with extremely high verticality by joining the division surfaces. The subsequent main tension is performed after the front, rear, left, and right beams 17 are placed on the corbel 4, or the tension is set so that the original stress is not generated according to the situation. Then, the PC steel rods 12 and 15 and the sheaths 2a and 3
After completion of the main tension, grout is injected into the gap with respect to a, the gap of the coupler sheath 2b, and the like, and the grout is cured to complete the self-supporting construction of the PC column 1.

After each upper pillar 2 is self-supporting, as shown in FIG. 6, another pillar 18 constituting the upper floor is sequentially added to the upper part of each upper pillar 2 via an adhesive, The PC steel materials are connected in series by the same connecting means as the long nut 16. Then, an appropriate beam 19 is laid over each layer, and a floor slab 20 is constructed to build each layer sequentially.

As described above, by accurately establishing the verticality of the base PC pillar 1 that constitutes the first floor, the PC pillars on the upper floors that are added to it can also be self-supporting with the correct verticality. , The building is built correctly as planned. Then, in the work of building the PC pillar, only the lower pillar block 3 which is light in weight and easy to handle is first installed, and it is not necessary to stretch the supporting wires and the like around the four circumferences to obtain the verticality. ,
The workability is remarkably good, and there is no hindrance when performing other work.

Further, since the upper columnar body 2 is simply added to the lower column block 3 which is correctly installed at the proper position at the beginning through the dividing surface, accurate verticality can be maintained and efficiently. It can be done and the construction period can be shortened.

[0034]

As described above, the PC according to the present invention is used.
The pillar is formed by dividing a precast concrete pillar into an upper pillar body and a lower pillar block, and when the upper pillar body and the lower pillar block are connected to each other, the pillar is divided into a single vertical pillar. Since the surfaces are aligned, the upper column and the lower column block can be handled separately, and the lower column block is easy to handle, so it is suitable for the top surface of a cast-in-place concrete foundation. Since it can be easily installed with a high degree of verticality, and an upper pillar can be added to it to make it self-sustaining, the workability of the PC pillar can be remarkably facilitated.

Further, the method for manufacturing a PC pillar according to the present invention is
By dividing the upper pillar and the lower pillar block at the same time by providing a predetermined dividing means in the integrated formwork for molding the precast concrete pillar, the dividing surfaces are aligned and the pillar body When connected as described above, there is an excellent effect that a PC column having a set in which the so-called verticality is maintained without distortion or angular deviation in the connected portion can be easily manufactured.

Further, in the construction method using the PC column according to the present invention, the precast concrete column is continuously connected to the pre-constructed cast-in-place concrete foundation to connect the PC steel material, and the PC steel material is tensioned to make the existing cast-in-place concrete. A method of standing a precast concrete column in which a foundation and a precast concrete column are integrated, wherein the precast concrete column is divided into an upper column body and a lower column block whose mating surfaces match, It is installed on the cast-in-place concrete foundation with the vertical plane of the lower pillar block as a reference, and the divided surface of the upper pillar is installed on the lower pillar block, and the PC steel rod of the upper pillar is PC steel of the lower pillar block. By connecting to the rod and applying a predetermined tension force, the lower column block which is light in weight and easy to handle is initially used. It is not necessary to tie support wires for verticality all around because it is necessary to set up the vertical poles and connect the upper pillars on it. , It has an effect of being excellent in safety without any hindrance in performing other work.

[Brief description of drawings]

FIG. 1 is a side view of a PC column according to an embodiment of the present invention.

FIG. 2 is a plan view schematically showing a mold for manufacturing the PC column of the embodiment.

FIG. 3 is an enlarged cross-sectional view of a main part showing a construction situation using the PC column of the embodiment.

FIG. 4 is a plan view showing a state where the lower pillar block of the embodiment is attached to a concrete foundation.

FIG. 5 is a side view of a long nut that connects the PC steel materials of the PC column in the embodiment.

FIG. 6 is a side view schematically showing a situation in which a plurality of floors are constructed using the PC columns of the embodiment.

FIG. 7 is a schematic side view showing a construction situation of an example using a conventional PC pillar.

FIG. 8 is a schematic side view showing a construction situation of another example using a conventional PC pillar.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 PC pillar 2 Upper pillar body 2a, 3a Sheath 2b Coupler sheath 3 Lower pillar block 4 Corbel 5 Formwork 6 Partitioning plate 7 Corbel forming part 10 Foundation pile 11 Concrete foundation 11a Top part 12, 15 PC steel material 14 Temporary receiving Rootstock 16 Long nuts 17, 19 Beams 18 Other PC columns

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location E04G 21/14 E04G 21/14

Claims (8)

[Claims] 1. A precast concrete pillar is formed by dividing it into an upper pillar and a lower pillar block, and when the upper pillar and the lower pillar block are connected to each other, a vertical pillar is formed. A precast concrete column, characterized in that the dividing surfaces are the same. 2. The precast concrete pillar according to claim 1, wherein a sheath into which at least a PC steel material is inserted is buried in the upper pillar and the lower pillar block. 3. The precast concrete pillar according to claim 1, wherein a corbel is integrally formed on the upper pillar. 4. A precast concrete pillar, characterized in that a predetermined dividing means is provided in an integral mold for molding the precast concrete pillar, and the upper pillar body and the lower pillar block are simultaneously molded in a divided state. Production method. 5. The method for manufacturing a precast concrete column according to claim 1, wherein the dividing means is a plate material or a sheet material. 6. The method for producing a precast concrete column according to claim 4, wherein a sheath into which the PC steel material is inserted is set at a predetermined position in the mold and concrete is placed. 7. A precast concrete in which a precast concrete column is connected to a preconstructed cast-in-place concrete foundation to connect PC steel, and the PC steel is tensioned to integrate the existing cast-in-place concrete foundation and the precast concrete column. A method of standing a pillar, wherein the precast concrete pillar is divided into an upper pillar body and a lower pillar block whose mating surfaces match each other, and the vertical plane of the lower pillar block is placed on the cast-in-place concrete foundation. Installed as a standard, install the divided surface of the upper pillar body on the lower pillar block, and connect the PC steel rod of the upper pillar body to the PC steel rod of the lower pillar block to give a predetermined tension force. Precast concrete pillar construction method characterized by. 8. The method for constructing precast concrete columns according to claim 7, wherein the upper precast concrete columns are sequentially connected and erected on the lower column block and the upper column body installed on the cast-in-place concrete foundation.