JPS6054166B2 - Pre-stressed concrete column and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pre-stressed concrete column and a method for manufacturing the same.

Conventional pre-stressed concrete pile (hereinafter referred to as PC)
Generally, piles (referred to as piles) are manufactured by the centrifugal crab method, but in this case, the head or both ends of the pile are anchored to the PC steel wire during pile manufacturing, and the total number of PC steel wires is At the same time, for the purpose of applying tension, an iron plate with a thickness of about 9 to 327Q, generally called a seat plate, is provided.

This plate can also be used for other purposes when joining PC piles to form a vertical shaft on site, by welding the PC pile plates above and below each other, but in the case of a single shaft. Since there is no need for bonding, this is only necessary during manufacturing.

In other words, in the case of single piles, the backboard becomes scrap when it is cut to align the pile heads at the construction site. These iron plates can cost anywhere from several thousand yen to tens of thousands of yen each, and using and discarding such expensive plates is not only a quality issue, but also a problem for the users of the piles. It has become extremely uneconomical.

In addition, the joint surface between the steel seat plate and concrete has the disadvantage that it is difficult to integrate, and the pile head tends to crack and break when driving at the construction site, and in order to improve the joint strength, the pile head structure must be further improved. The disadvantage is that it is complicated and economically expensive.

In order to improve the above drawbacks, the present invention has been developed to replace this expensive seat plate by incorporating several Pctl/4-wire anchoring hardware that can tension-fix a PC steel wire using reinforced concrete as the main material. This method is extremely economical, as it is possible to manufacture PC piles in the same way as before by manufacturing reinforced concrete end pieces in advance and setting these end pieces when manufacturing PC piles. ,
In addition, pile heads with high strength and irregular cross-sections can be obtained in a remarkable and economical manner.

Next, the present invention will be explained in detail.

The end piece P is manufactured in advance into a desired shape according to the shape of the concrete column (i.e., quadrangular, triangular, hexagonal, circular, cylindrical, etc.) using formwork and reinforced concrete. The thickness of the piece should be approximately 5 to 30 cm, and the weight should be such that the piece can be easily transported.

To manufacture the end face piece P, a required number of PC steel wire anchoring hardware 1 is buried in the head of the end face of the saw.

As shown in FIG. 6, this PC steel wire anchoring hardware 1 has a hole 3 in the bottom plate 2 that is larger (than the diameter of the PC steel wire through which the Pq steel wire can penetrate), and the reinforced concrete behind this hole 3 A PCW 4-wire insertion hole 5 of the same diameter is opened in the 6th part toward the joint surface 7. The bottom plate 2 of the PC steel wire anchoring hardware 1 is integrated with a threaded portion 4 having a diameter that allows the tension steel rod 13 to be joined.
The upper surface of the end piece P is made to match or be buried in the concrete upper surface 8 of the end piece P.

Further, it is also possible to provide a plurality of anchored PC steel wires 9 and their holes (3 and 5) for one threaded portion 4. Does the back surface (joining surface) 7 of the end piece P touch the main concrete of the concrete column? In some cases, unevenness 11 as shown in FIG. 3 is provided for the purpose of increasing the adhesion area and increasing the shear resistance. Or the back side 7 of the end piece P
If necessary, reinforcing bars 12 for joining with the main body concrete may be made to protrude. The reinforced concrete end piece manufactured in advance in this manner is shown in FIGS. 4 and 5.

When manufacturing pre-stressed concrete columns,
The necessary number of PC steel wires 9 necessary for the first column are accurately cut to a predetermined length, and a button head 10 for anchoring is attached to one end of the PC steel wire 9.
Process.

Next, the two reinforced concrete end pieces Pl and P2 are temporarily placed on the formwork bottom plate 16 at appropriate intervals, and the holes 3 and PC of the PC steel wire anchoring hardware 1 of one end piece P1 are
Pass the PC#11 wire 9 through the steel wire insertion hole 5 from the side where the anchor button head 10 is not processed, and insert the end of the steel wire into the PC steel wire insertion hole 5 of the other end piece P2 and the PC
The steel wire is passed through the anchor fitting 1 and pulled out to a sufficient length from the end piece to process the anchor fitting button head 1''.

After that, one of the end pieces Pl, P2 is aligned with the edge of the formwork, and the other end piece P2 is moved to connect the Pq steel wires 9, 9.
The anchor attachment button heads 10, 1' of . . . are brought into close contact with the bottom plate 2 of the PC steel wire anchor attachment hardware 1. The end piece P1 placed at the end of the mold is fixed to the mold fixing side plate 17 with bolts 18. The end piece P2 at the other end is the PC steel wire anchoring hardware 1
A tension steel rod 13 is inserted and joined to the threaded portion 4 of the tension steel rod 13, and the other end of the tension steel rod 13 is fixed to the movable side plate 19 with a nut 20. The rod 21 of the hydraulic jack is attached to the center of the movable side plate 19, and when the movable side plate 19 is pulled outward, the end piece P2 is pulled out by the tension steel rod 13, and the PC steel wire 9
A predetermined tension force can be introduced into. Next, concrete 1C for the column is cast between the end pieces Pl and P2, and sufficient vibration compaction or centrifugal force compaction is performed, and the concrete is cured until demolding strength is reached.

After curing is completed, the tension steel rod 13 is cut off from the end piece P2, and the formwork fixing side plate 17 is cut off from the end piece P1, so that the concrete column 14 hardened by curing and the reinforced concrete end pieces Pl, P2 at both ends are separated. This completes a pre-stressed concrete column 15 in which concrete is joined and integrated.

Now, the purpose of the end piece is not only to anchor the end of the CW4 wire, but also to protect the end face of the pillar.

For example, for piles that are subject to impact, concrete is required to have a higher strength than that of the column body. Therefore, the end piece has high compressive strength to increase impact resistance, and
It is desirable to use reinforced concrete such as fiber-reinforced concrete, polymer concrete, or ferrocement, since it is necessary to increase tensile strength.
In order to clarify this, the above manufacturing method was explained as a pre-tension method, but for example, some of the PC steel wires may be covered with unbonded PC steel wires or sheaths to prevent them from adhering to the poured concrete. By doing so, it can be easily applied to the post-tension method, and the end piece can be used as is.

In the pre-stressed concrete column manufacturing method of the present invention, the end piece is manufactured in advance into a desired shape to match the shape of the concrete column (i.e., square, triangular, hexagonal, circular, cylindrical, etc.). However, since conventional steel counters are made of concrete, they can easily be made into shapes that would be extremely expensive due to the modification of processing machines at ironworks and the loss of iron plates.
Moreover, it can be produced economically. In addition, in this pre-stressed concrete column, the threaded part of the PC steel wire anchoring hardware can be used to screw and fix mounting bolts in structures where the column is combined with other members, such as girders, beams, etc. ,
This is effective for the connection, and this can greatly expand the range of uses of a column having such an end piece.

Furthermore, the side surfaces of the end pieces do not necessarily have to be perpendicular to the column axis, but can be at any angle, making the side edges beveled or having different shapes and dimensions from the main body of the column. Pre-stressed concrete columns with irregular cross-sections (see FIG. 9) can also be obtained simply and easily. As explained above, the present invention aims to replace the conventional iron plate type seat plate with an end piece made of pre-formed concrete made of reinforced concrete as the main raw material. In addition, it is possible to eliminate the back plate, which is disadvantageous in terms of resources, or to solve the conventional problem of the joint surface between the steel seat plate and the concrete column body (not being integrated) by eliminating the unevenness of the joint surface of the end piece. This problem can be easily solved by installing joint reinforcing bars, etc., and the strength of the concrete column head is increased by increasing the attachment area and shear resistance, making it a durable pre-stressed concrete column. It has the characteristics that it can be economically obtained at low cost and that it can further improve the performance of the product.

[Brief explanation of the drawing]

Fig. 1 is a slope view showing an example of the pre-stressed concrete column of the present invention, Fig. 2 is a vertical cross-sectional view showing the same molded state, and Fig. 3 is a cross-section of the reinforced concrete end piece of the present invention. 4 is a side view of a square end piece, FIG. 5 is a side view of a round end piece, and FIG. 6 is a side view of a square end piece.
．． B is a slope view and a cross-sectional view showing an example of the PC steel wire anchoring hardware built into the end piece; FIG. 7 is a longitudinal cross-sectional view of a pre-stressed concrete column manufactured by the method of the present invention;
FIG. 8 is a longitudinal sectional view showing a modification thereof, and FIG. 9 is a side view showing a concrete column with a modified cross section at the end. 1...PC steel wire anchor hardware, 6...Reinforced concrete P. ．． Pl and P2... Reinforced concrete end piece, 9... PC steel wire, 10, 1'... PC steel wire button head, 14... Concrete column body, 15...
Pre-stressed concrete columns.

Claims (1)

[Scope of Claims] 1. Reinforced concrete end pieces containing several PC steel wire anchoring hardware are provided at both ends, and the distance between the end pieces extends within both PC steel wire anchoring hardware of both end pieces. A pre-stressed concrete column in which both end pieces and the concrete column are integrated by fixing the PC steel wire under tension and pouring concrete for the column to form a concrete column in which the PC steel wire is embedded. 2. The pre-stressed concrete column according to claim 1, wherein the end piece has irregularities or reinforcing bars for joining on the joint surface (back surface). 3 Install two reinforced concrete end pieces containing several pieces of PC steel wire anchoring hardware at the required interval, and tension the necessary PC steel wires across both PC steel wire anchoring hardware on both end pieces. After that, concrete for the column is cast within the interval between both end pieces surrounded by formwork, and vibration compaction or centrifugal compaction is performed to integrate both end pieces and the concrete column body. Manufacturing method for pre-stressed concrete columns. 4. The method for manufacturing a pre-stressed concrete column according to claim 3, characterized in that the joining surface (back surface) of the end piece is provided with irregularities or joining reinforcing bars.