JPH0230504A - Manufacture of precast concrete member - Google Patents

Abstract

PURPOSE:To contrive an elimination or reduction of labor in execution such as transportation and close built-up, by a method wherein after setting-up of a fixed leverlike mold material at an arranging position of a reinforcing steel material such as a main streak in a shuttering, concrete is loaded, the same shuttering is turned and consolidation and sticking of the concrete to an inner circumference of the same shuttering are performed through centrifugal force. CONSTITUTION:A leverlike mold materials 5 constituted of a tubular body round of the outer circumference of which a shearing reinforcing rod 4 is wound are arranged on positions of four corner parts where necessary protective cover thickness is held, in the inside of an outer circumferential shuttering 1. Then ends of the leverlike mold materials 5 each are fixed to fixing holes 3a of the leverlike mold materials of side part shuttering 3 arranged on both side opening parts of the outer circumferential shuttering 1 and the leverlike mold materials 5 are set up at the fixed positions. Then a fixed quantity of concrete 6 is loaded into the outer circumferential shuttering 1 and both side part shutterings 3. The shuttering is turned around its lengthy direction as an axis and the concrete 6 is fixed to an inner circumferential surface of the shuttering through consolidation by centrifugal tamping. Then the leverlike mold material 5 is pulled off along with demolding and a hollow precast concrete pillar A also serves as the shuttering into the outer circurmference of which the shearing reinforcing rod 4 is driven is molded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for manufacturing precast concrete members such as architectural columns and beams.

(Prior art) In conventional precast concrete columns for construction, a sheath is buried through the main reinforcement section, and the main reinforcement is inserted into the sheath section at the site and Grau I is injected, or a splice sleeve is inserted into the precast concrete column. A method was used in which a metal joint such as the above was attached to the tip of the main reinforcing bar, and after the construction was carried out on site, grout was injected into the part of the metal joint.

(Problem to be solved by the invention) In the former case, the main reinforcement part is hollow and the remaining part is filled with concrete, so the weight per piece of the precast concrete column becomes large.
Large machinery will be required for transportation and erection. Furthermore, grouting work was added to the site in addition to concrete pouring, which caused problems with the rationality and labor-saving of the work.

On the other hand, when a steel sheath pipe is used for the sheath part, when manufacturing a precast concrete column, since the sheath pipe is a thin-walled steel pipe, the sheath part will be They often deviate from their predetermined positions, often causing problems.

In the latter case as well, each piece of precast concrete column weighs a lot, requiring large machinery for transportation and erection, and also requires grouting, which poses problems in terms of labor saving. there were.

The present invention was proposed in view of the problems of the prior art, and provides an improved method for manufacturing precast concrete members that is structurally rational and saves labor in transportation, erection, etc. At the point.

(Means for Solving the Problem) In order to achieve the above-mentioned object, the method for manufacturing a precast concrete member according to the present invention provides a method for manufacturing a precast concrete member, in which reinforcing steel materials such as main reinforcements are placed on the outer periphery in a formwork for manufacturing a precast concrete member. After setting the rolling form material wrapped with shear reinforcing bars, a predetermined amount of concrete is poured into the formwork,
The mold is rotated around its length, and the concrete is solidified on the inner peripheral surface of the mold by centrifugal compaction, and then the rod-shaped material and the mold are removed.

(Function) According to the present invention, as described above, a rod-shaped material having shear reinforcing bars wrapped around its outer periphery is set in a formwork for manufacturing precast concrete members at the location where reinforcing steel materials such as main bars are provided,
After that, a predetermined amount of concrete is poured into the formwork, and by rotating the formwork around its length, the concrete poured into the formwork is compacted by centrifugal force, and the inner periphery of the formwork is compacted. By compacting and adhering to the surface, removing the same formwork, and pulling out the rod-shaped material, a hollow precast concrete member that also serves as a formwork and has the shear reinforcing bars driven into its outer periphery is manufactured.

(Example) The present invention will be described below with reference to the illustrated embodiments.

(1) is an outer peripheral formwork with openings on the upper end surface and both longitudinal sides, (2) is an upper formwork that is detachably installed in the upper end opening of the outer peripheral formwork (1), and (3) is The side formwork is removably disposed in the openings on both sides of the outer peripheral formwork, and rod-shaped shape fixing holes (3a) are bored in the four corners, and the outer peripheral formwork (
1), the upper cover (2), and both side formworks (3) constitute a formwork for manufacturing a precast concrete column.

4 that maintains the required cover thickness within the outer peripheral formwork (1).
Shear reinforcing bars (4) are wrapped around the outer periphery at the corner positions.
A rod-shaped material (5) composed of a tube body is disposed, and the ends of each rod-shaped material (5) are connected to side forms (5) arranged at both openings of the outer peripheral form (1). 3), and set the rod-shaped material (5) in a predetermined position.

Next, a predetermined amount of concrete (6) is poured into the outer peripheral formwork (3) and both side formworks (3). (See Figure 1) Next, an upper formwork (2
) to close the openings, thus each formwork (
1) The formwork for manufacturing precast concrete columns assembled by (2) and (3) is rotated around its length, and concrete (6) is formed by centrifugal compaction.
is compressed and fixed to the inner circumferential surface of the formwork (see Fig. 2), and then removed from the mold and pulled out the rod-shaped material (5).
A hollow precast concrete column (8) that also serves as a formwork is formed, with shear reinforcing bars (4) driven into the outer periphery. (
(See Figures 3 and 4) Figure 6 shows the case where the method of the present invention is applied to a precast concrete column with a column head and jaw, and shows one side formwork (3'
) with a bottomed bent part (3'
A) is bent, and a closing part (3A) of the upper end opening of the bent part (3'A) extends from one end of the upper formwork (1). The same reference numerals are given to parts equivalent to those of the above embodiment.

Figure 7 shows a precast concrete column (A') with a jaw (B) formed by the formwork, Figure 8 shows a construction example using the same precast concrete column (8'), and (C) shows a construction example using the same precast concrete column (8'). Precast concrete, etc. loaded on the jaw (B) of the stud (A'), (D) is the beam top reinforcement, (E
) is the beam bottom reinforcement, and the precast concrete column (A
The column main reinforcement (
At the same time, insert the bent end of the beam bottom reinforcement (F) into the turn using the hollow part of the pillar (8'), and insert the bent end of the beam bottom reinforcement (F) into the hollow part of the stud (8') and (8') Concrete is poured between the upper part and the above-mentioned column (C), and also on the same column (C), and the column (A') is made to serve as a formwork with a brad. ') and the above-mentioned name (C) are integrated.

(Effects of the Invention) According to the present invention, as described above, after setting a rod-shaped material with shear reinforcing bars wrapped around its outer periphery at the location where reinforcing steel materials such as main bars are placed in a formwork for manufacturing precast concrete members, A predetermined amount of concrete is poured into the formwork, the formwork is rotated around its length direction, and the concrete poured into the formwork is consolidated and fixed to the inner peripheral surface of the formwork by centrifugal compaction. , then the rod-shaped material and the formwork are removed, and by appropriately selecting the cross-sectional area of the rod-shaped material, a precast concrete member having a hollow part with a larger cross-sectional area than conventional precast concrete members can be created. Concrete members can be manufactured. Furthermore, when assembling precast concrete columns and beams, the ends of the beam reinforcements are fixed in the hollow portions of the precast concrete members, making it easy to place concrete.

In addition, since the shear reinforcing bars are driven into the outer circumferential surface of the hollow part of the precast concrete member, the concrete placed in the hollow part connects to the main body of the precast concrete member via the shear reinforcing bars. integrated,
A structure with high strength and high reliability can be constructed.

Furthermore, since the hollow portion of the precast concrete member manufactured by the present invention is large, there is flexibility in design and construction when arranging main reinforcements and reinforcing bars, and it is possible to correspond to a wide range of reinforcement arrangements.

Furthermore, since the present invention is a method of manufacturing a precast concrete member using centrifugal force, a thin member is formed, the weight of the member is reduced, and construction labor such as transportation and erection can be saved.

[Brief explanation of the drawing]

Figures 1 to 3 are longitudinal sectional views showing the steps of an embodiment in which the present invention is applied to the production of precast concrete columns;
The figure is a perspective view of a precast concrete column manufactured by the above method, FIG. 5 is a perspective view of a formwork used in the above method, and FIG. 6 is a perspective view of a formwork used in another embodiment of the method of the present invention. FIG. 7 is a perspective view of the formwork, FIG. 7 is a perspective view of a precast concrete column manufactured by the same method, and FIG. 8 is a longitudinal sectional view showing an example of construction using studs. (+)-m-Outer formwork (2)---Upper formwork (3
)(3')---1 Side formwork (4)---Shear reinforcing bar (5)-m-rolling material (6)---Concrete agent Patent attorney Shige Okamoto 2 other people

Claims (1)

[Claims] After setting a rod-shaped material with shear reinforcing bars wrapped around its outer periphery at the location where reinforcing steel materials such as main reinforcements will be placed in the formwork for manufacturing precast concrete parts, a predetermined amount of concrete is poured into the formwork, and the same formwork is removed. The production of a precast concrete member is characterized in that the rod-shaped formwork and the formwork are removed after the concrete is rotated around its length direction as an axis and the concrete is compacted and fixed to the inner circumferential surface of the formwork by centrifugal compaction. Method.