JPS6332063A - Method for preventing expansion of cast spliced part in sliding foam construcion method - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Industrial Field of Application This invention is mainly concerned with a sliding formwork method for constructing silos and other cylindrical concrete structures, in which concrete is poured by sequentially raising the formwork, and more specifically, Sliding form construction method, in which the wall thickness and slope are constant, or slip form construction method (variable section construction method), in which the circumference, slope, and wall thickness can be freely changed (hereinafter collectively referred to as sliding form construction method, etc.). In this field, it is necessary to prevent concrete wall bulges that occur at the bottom of the formwork at the joint part and reduce the amount of repair work, especially when concrete is poured discontinuously to avoid late-night work. This invention relates to a method for preventing bulges at joints.

A feature of conventional techniques such as the sliding form construction method is that concrete can be placed continuously and a concrete structure with high integrity can be constructed.

However, in recent labor conditions, it is difficult to continue working day and night, so it is difficult to continue pouring and pouring concrete non-continuously during normal working hours every day, strictly observing working hours and working conditions. It has become common.

In that case, at the time of completion of concrete pouring on the previous day, the fourth
As shown in Figure A, concrete b is placed almost to the full height of steel formwork a. However, until the start of the next day's work, the steel formwork a was slid at regular intervals on the order of several C11 in order to cut the edges to prevent the steel formwork a from adhering to the concrete (b). I'll keep letting you do it. Therefore, at the start of the next day's pouring work, the steel formwork a had risen as shown in Figure B. Moreover, formwork a usually has 4
/ Since there is a draft angle of about 1000 degrees, there is a misalignment (inclination) of about 172 (2 ma+) of the formwork slope in the concrete b of the previous day at the pouring joint.

Furthermore, when the concrete d was poured, a bulge e sometimes occurred at the lower part of the formwork a at the pouring joint, as shown in FIG. 4C. In other words, the formwork a of the sliding form construction method is supported in a protruding manner at the bottom of the yoke, so the formwork a may be damaged due to variations in slump during concrete pouring, pouring speed, excessive use of vibrators, etc. In some homes, it tends to open downwards, causing a bulge e at the bottom.

Problems to be solved by the present invention Conventionally, today's concrete 1 was poured as shown in Figure 4C.
If a bulge e occurs in 1, scrape off the bulge part of the concrete with a plastering board or a metal trowel as shown in Figure 5.
Repairs are being made with resin warts f to eliminate misalignment.

Therefore, it takes a lot of time and effort to scrape off the protruding concrete ld, clean it, and repair it with resin mortar f, resulting in high costs.

Means for Solving the Problems As a means for solving the problems of the above-mentioned prior art, a method for preventing bulges at the joints in the sliding form construction method, etc. according to the present invention is shown in FIGS. 1 to 3 of the drawings. As shown in the example, in the pour joint part of the sliding form construction method, etc., where concrete is poured discontinuously.

A lateral pressure receiving material 2 such as expanded metal is attached to the inside of the reinforcing bars 1, 1 at the joint, and then concrete 3 is poured and the joint is made.

Since the lateral pressure receiving material 2.2 is attached to the inside of the reinforcing bars 1.1 at the pour joint part, today's concrete 3 is poured and the pour joint is performed, the lateral pressure exerted by the concrete 3 on the steel formwork 4 is Most of the load is borne by the side pressure receiving material 2.2, and it does not exert much force on the formwork 4.

Therefore, the support of the formwork 4 by the yoke will never succumb to the lateral pressure of the poured concrete 3, and even if the vibrator is applied too much, the lower part of the formwork 4 will never bulge. Therefore, the trouble of scraping off the protruding concrete wall and cleaning it can be almost eliminated.

Embodiment Next, the present invention will be explained in detail as shown in FIGS. 1 to 3 of the drawings. First, FIG. This figure shows the structure of a concrete structure constructed using the sliding form construction method, etc. at the start of work the next day.

That is, the inner vertical reinforcing bars l protrude from the top of the previous day's concrete 5 surrounded by a pair of inner and outer steel formworks 4.4,
Extended metal 2 as a side pressure receiving material is placed inside of 1.
2 was attached using a method such as binding with wire, and then today's concrete 3 was poured.

The total height of the formwork 4 is usually about 1m, and due to edge cutting sliding, at the time of pouring, it is 50cm higher than the top of the concrete 5 from the previous day.
Considering that the height of concrete 3 is approximately 20 to 30 cm, the maximum height of the expanded metal 2 is 30 cm.
It is said to be the highest rank.

Regarding the details of the structure of this expanded metal 2, as a part of it is shown enlarged in Fig. 2, the opening size is about 35 x 10 mm for aXb, and 10 mm for plate @C.
The plate pressure is said to be about 1.2 am.

Since the concrete 3 is cast after the expanded band metal 2 is installed in this manner, the concrete is poured simultaneously on the inside and outside across the extreme band metal 2.

In this way, even if concrete is poured and the vibrator is sufficiently applied, most of the concrete lateral pressure acting on the formwork 4 is borne by the expanded metal 2, and no bulging will occur at the bottom of the formwork 4. First, the concrete inside the reinforcing bar 1 and the cover concrete outside are completely integrated through the expanded metal 2.

The joints of the concrete structure constructed in this way are
As shown in FIG.
The result is such that there is a difference in quality.

Therefore, there is no need to scrape off the edges of the concrete wall or clean it after construction, and it is sufficient to simply fill in the misaligned parts with resin mortar 6 and finish.

Other Embodiments As the lateral pressure receiving material for concrete, it is not limited to the above-mentioned expanded metal 2, but for example, so-called re-plus which is added with angles to give rigidity, or a perforated plate can be similarly used.

The effects of the present invention have been described in detail in conjunction with the embodiments, and according to the method for preventing bulging of the pouring joint in the sliding form construction method, etc., according to the present invention, the side pressure receiving material 2 is placed inside the reinforcing bar 1. A simple pre-treatment for installation can almost completely prevent concrete from protruding at pour joints.

Therefore, it is possible to eliminate most of the time and effort required for repairs such as scraping off the edges of the concrete wall and cleaning, thereby reducing costs and shortening the construction period.

Furthermore, the quality and precision of the constructed concrete structure can be improved.

[Brief explanation of drawings]

Fig. 1 is a construction drawing in which the method for preventing bulging of a spliced joint according to the present invention is implemented, Fig. 2 is an enlarged explanatory diagram of expanded metal, and Fig. 3 is a construction drawing of a spliced joint constructed by the method of this invention. 4A, B, and C are construction explanatory diagrams of a conventional pouring joint, and FIG. 5 is a cross-sectional view showing a concrete wall at a conventional pouring joint. Figure 1 Figure 3 Figure 4 A b

Claims (1)

[Scope of Claims] [1] In the pour joint part of the sliding form construction method, etc. in which concrete is poured and jointed discontinuously, lateral pressure such as expanded metal is applied to the inside of the reinforcing bars (1) (1) of the pour joint part. A method for preventing bulging at a pouring joint in a sliding form construction method, etc., which is characterized by installing a receiving material (2), and then pouring concrete and performing a pouring joint.