JPH042134B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a method for removing excess concrete formed on the top of a concrete structure constructed underground, such as a cast-in-place concrete pile or an underground continuous wall. Regarding processing methods for

[Conventional technology and problems]

For example, when constructing cast-in-place concrete piles, a slime mixture occurs at the top of the cast concrete, so an extra layer of an appropriate height is provided at the top of the pile, and after the pile is completed, this extra layer is removed. By removing this, a concrete pile with excellent strength having a pile cap at a predetermined height position is obtained.

If the above-mentioned excess portion is removed by chiseling, the problem arises that the removal takes time and the work cost is high.

Therefore, according to Japanese Patent Application Laid-Open No. 60-62328, a bucket made of metal plate is pushed into the excess pile after concrete is poured and buried, and when the concrete starts to harden properly, the bucket is pulled up and the A construction method has been proposed to remove this.

By the way, the conventional backfill treatment method using metal plate buckets can only use buckets that fit within the inner diameter of the reinforcing bar cage, and as a result, only a small amount of backfill concrete is removed, and a large amount of backfill concrete remains, resulting in Post-processing takes time and effort, and is not effective as an overfill process.

Another problem is that when the bucket is buried, the upper end surface of the extra concrete rises by the volume of the bucket, and this spills onto the ground, causing contamination.

Therefore, in order to solve the above-mentioned problems, this invention makes it possible to remove the excess concrete to a position close to the outer shape of the structure, thereby significantly eliminating post-processing, as well as preventing the excess concrete from flowing out from the ground. The objective of the present invention is to provide a method for treating excess concrete that does not cause contamination.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention includes a method in which a mesh member having an insertion hole for a tremie pipe for concrete injection is set in advance at the position of the extra heap of a concrete structure together with reinforcing bars before concrete is poured. After that, the mesh members are buried in the extra heap by pouring concrete, and when the concrete begins to harden, the mesh members are lifted up and the extra concrete is removed together with the mesh members. It is.

[Effect]

A mesh member is buried in the upper end of the structure formed by pouring concrete.

To bury mesh members in the backfill area, set the mesh members together with reinforcing bars at the location of the backfill area before pouring concrete, and then suspend the mesh members when the concrete begins to harden after pouring the concrete. When lifted, the excess concrete in the part where the mesh members are buried becomes integrated with the mesh members and is lifted up, and the excess concrete is separated and removed from the structure body at the lower part of the mesh members. .

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 to 3 and 4 to 7 each show a different example of the mesh member used in the practice of the present invention.

First, the first example shown in FIGS. 1 to 3 is a mesh basket made of a combination of a cylindrical basket body 1 and a bottom cover 3 that is detachably attached to the lower part of the basket body 1 with bolts 2. The main body 1 of the basket is formed by connecting the upper and lower rings 5 and 5 using a flat bar with a large number of vertical stripes 6, and the mesh 7 is stretched around the outer periphery. A reinforcing bar 9 is provided at the bottom, a mesh 10 of PC wire is stretched on the bottom surface, and a hole 12 for attaching a sheath 11 is provided at the end of the reinforcing bar 9.

An insertion hole 31 is provided in the center of the bottom cover 3 for inserting a tremie pipe for inserting concrete.

Next, the second example of the mesh basket 4 shown in FIGS.
a, and the two are removably connected by bolts 13, and a mesh bottom part 14 in the form of a half ring is provided on the inner periphery of the lower end of both single parts 4a, 4a, and a separate mesh bottom part 14 is provided on the inner periphery of both bottom parts 14, 14. The bottom cover 3a is installed by dropping it from the top,
A bolt hole provided on the inner periphery of the bottom part 14 is provided so that a lifting shell or hook 11 can be attached. An insertion hole 31 into which a tremie tube is inserted is provided in the center of the bottom cover 3a.

Using the mesh basket of the second example as described above, construction of cast-in-place concrete piles and removal of excess concrete will be explained according to the process diagram shown in FIG. 8, a to f.

As shown in FIG. 8a, a casing 21 is inserted into the ground where a pile is to be constructed, the inside thereof is excavated, and a reinforcing bar cage 22 is erected inside the casing 21.

In this state, a mesh cage formed to have an outer diameter that fits inside the casing 21 is suspended by a wire 26 and externally inserted into the reinforcing bar cage 22, and this mesh cage 4 is suspended and held at a position corresponding to the extra heap of concrete. and set it.

As shown in FIG. 8b, the tremie pipe 25 is inserted into the insertion hole 31 provided at the bottom of the mesh basket 4 inside the casing 21, and concrete is poured while pulling up the tremie pipe 25. Concrete A is filled to a predetermined height as shown in FIG. 8c, and the mesh basket 4 is embedded in the concrete A.

After burying the mesh basket 4, pull out the casing 21 as shown in FIG. lift.

Concrete A that is in the middle of hardening is stuck to the mesh basket 4 at the bottom and surrounding walls of the mesh basket 4, so when the mesh basket 4 is pulled up as shown in FIG. It is torn off, and the upper part of the poured concrete A is removed together with the mesh basket 4.

In other words, the part of concrete A into which the mesh basket 4 is inserted and buried is the excess concrete A', and this surplus part will be pulled up and removed together with the mesh basket 4, and the pile head will be leveled with a trowel before the concrete hardens. If this is done, the head of the pile B formed by the hardening of the concrete A will be finished with a smooth surface.

The upper space of the pile B formed as above is the 8th
Until the foundation is built on top of it, as shown in Figure f,
It should be backfilled.

In addition, although the example shows the case where the excess concrete of a cast-in-place concrete pile is removed, the excess concrete of an underground continuous wall can also be removed in the same way, for example, by forming the mesh basket horizontally long. . Further, although a mesh basket is used as the mesh member, the same removal process can be performed using only the bottom cover shown in FIGS. 1 and 6.

〔effect〕

As described above, according to the present invention, the mesh member is set in advance together with reinforcing bars at the position of the extra heap before concrete is poured, and the mesh member is buried in the extra heap of the poured concrete, so that the concrete does not clump. As the mesh members are lifted up at the time of loading and the excess concrete is peeled off and removed together with the mesh members, the excess concrete can be removed by setting and hoisting the mesh members, greatly improving work efficiency. It is possible to reduce work costs.

Furthermore, by omitting the chiseling work, it is possible to eliminate the occurrence of occupational diseases caused by vibrations, and to prevent noise pollution caused by the chiseling work.

Furthermore, since the mesh members can be fitted externally to the reinforcing bars, the mesh members can be formed to a size that matches the inner diameter of the structure, and since the mesh members have good bonding properties with concrete, the entire concrete excess area can be reliably secured. Can be removed. There is no need to chisel the excess portion.

Furthermore, since the mesh member is set in advance at a position corresponding to the extra heap, there is no possibility that the extra heap of concrete will flow onto the ground and cause contamination.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view showing a first example of a mesh member used in carrying out the present invention, FIG. 2 is a plan view showing the assembled state of the same, FIG. The figure is an exploded perspective view showing the second example of the same, Figure 5 is a perspective view of the bottom cover used in the above, Figure 6 is a plan view of the assembled state, Figure 7 is an enlarged sectional view of the main parts of the same,
FIGS. 8a to 8f are explanatory diagrams of processing steps using a mesh basket. 1...basket body, 3, 3a...bottom cover, 4...mesh basket, A...concrete, A'...surcharge concrete, B...pile.

Claims (1)

[Claims] 1. A mesh member having an insertion hole for a tremie pipe for concrete injection is set in advance at the position of the excess portion of a concrete structure, together with reinforcing bars, before pouring concrete, and then, by pouring concrete, the mesh member is This is a method for processing excess concrete, characterized by burying it in the excess concrete, lifting the mesh members when the concrete begins to harden, and removing the excess concrete part together with the mesh members.