JPH047407A - Manufacture of foamed body at job site - Google Patents

Abstract

PURPOSE:To improve soft ground by a simple method by feeding steam into preexpanded grains filling a space formed into the ground by digging so as to form a foamed body and covering the surface of the foamed body with asphalt pavement after the foamed body is covered with soil and sand. CONSTITUTION:Expandable plastic resin grains are fed into the tank of a continuous preexpanding machine 22 coupled with a small-sized boiler 21 and a space 12 formed into the ground 11 by digging is filled with preexpanded grains 30 which are produced by foaming the grains to 10-80 times larger. A steam feeding pipe 40 is inserted into the space 12 from the hole 51 of a veneer board 50 covering the opening of the space 12 and the surface of the veneer board 50 is covered with soil, sand, gravels, etc., 50. Then the pipe 40 is connected with the pipe 23 of the boiler 21 and steam is fed into the space 12. After a foamed body is formed by heating the preexpanded grains, the entire surface of the foamed body is covered with soil and sand and a road, etc., is constructed by installing a concrete floor 80 and covering the floor 80 with asphalt pavement 90. Therefore, soft ground can be improved by easily producing a foamed body at a job site.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to foam molding that is used by filling in the ground when constructing roads, buildings, bridges, etc. on soft ground or on ground where underground structures are located. The present invention relates to a method for manufacturing a body at a construction site.

[Conventional technology]

Conventionally, in order to reinforce soft ground, as shown in Figure 5 (a), a density of 0.02 g/cm was applied to the soft base soil 1.
Blocks 2, 2, etc. made of expanded polystyrene of ~0.05 g/c+n3 are stacked as shown in Figure 5 (b), a covering soil 3 is provided on top of the blocks, and concrete or asphalt is placed on top of it. Pavement layer 4 was provided. Figure 1 (c) shows the case where the construction is done adjacent to the pier 5. [Limestone (233) May 1988 issue [Civil engineering method using expanded polystyrene (EPS method)] Written by Hideki Tsukamoto,
Pages 63-69], [23rd Soil Engineering Research Conference Lecture Proceedings, June 1986 EP on Full-Scale Experiment of rEPS Construction Method
"Behavior of S Embankment" by Gosanbe Miki and Hideki Tsukamoto, 1985-1
988 pages], (rEPs construction method design manual J, Styrofoam Civil Engineering Development Organization, August 30, 1988, daily publication), [
See JP-A-62-45801, JP-A-63-81941, JP-A-63-112544, JP-A-63-1144.

The construction method using the foam blocks 2 is cheaper than pile driving 2, lime stabilization, soil packaging, etc., and the blocks are lightweight, making them easy to work with, and their buoyancy reduces the weight of buildings, pavements, etc. on the foundation soil. There are advantages such as: Therefore, in the past, when improving soft ground using additional soil, it was only possible to construct concrete buildings and roads after leaving the soil for 4 to 5 years to consolidate it. By using soil instead of soil, there is no need for a consolidation period, and construction can be completed in an extremely short period of time.

[Problem to be solved by the invention]

The above block is manufactured by extrusion foam molding method and in-mold bead foam molding method, and has a length of 2000 mm.

Width 1000mm, height 500mm, density 20kg/m'
(foaming ratio: 50 times) and weighing approximately 13 kg/piece is used as one of the products specified by the Styrofoam Civil Engineering Development Organization.

Blocks are formed by the processing manufacturer as described above, and then transported by truck to the site and reclaimed.
True density of raw material polystyrene resin pellets 1 kg/m'
Compared to raw material pellets, transporting blocks is like transporting 1 part of raw material pellets and 49 parts of air, which means the transportation cost is high ().

In addition, construction sites are scattered throughout the country, so each region requires a processing manufacturer and molds and dies to obtain the blocks, making it difficult to invest in equipment.

Therefore, if the foam blocks could be molded at the site where the reclamation work is being carried out, transportation costs would be significantly reduced, and there would be no need to distribute the molding equipment that forms the blocks all over the country.

It is conceivable to install extrusion foam molding equipment or in-mold foam bead molding equipment on a large trailer, move it to the construction site, and mold the blocks on site, but it is possible to use the trailer during the idle period after block molding. This is not a good idea considering the use of molding equipment.

An object of the present invention is to provide a method for manufacturing a foamed molded product extremely easily using a simple device at a site where the foamed molded product block is buried in the ground.

[Specific means to solve the problem]

As a means for achieving the above object, the present invention provides a pre-foamed thermoplastic resin in which, after excavating a construction site in the ground into a desired shape, expandable thermoplastic resin particles are expanded 10 to 80 times from the opening of the excavation site. Fill the excavated space with particles, then cover the open opening of the excavated area with a board, earth, etc., and then heat the pre-foamed thermoplastic resin particles with pressurized steam to foam and fuse the particles together. The present invention provides a method for manufacturing a foam at a construction site, which is characterized by forming a foam molded product.

[Effect]

Using a small boiler, a continuous pre-foaming machine with a diameter of 0.5 m and a height of 1.5 m, and a steam supply pipe, the expandable thermoplastic resin particles are first pre-foamed to a desired ratio on-site to obtain pre-foamed particles. After filling the excavated ground space (concavity) with this, the opening on the filling side of the excavated area is opened using the foaming force of the pre-expanded particles during foam molding so that the foamed particles do not rise above the desired height. The space is covered with a plate, earth and sand, etc., and then 0.1 to 4 kg/cm2 of steam is supplied from a steam supply pipe located in the space filled with pre-foamed particles, and the pre-foamed particles are heated with steam to pre-foam them. A foam molded article is produced by foaming (expanding) and fusing the particles.

Since the ground soil is permeable and steam escapes from the soil, there is no concern that an accident may occur due to an explosion at the construction site.

[Examples, etc.]

Hereinafter, the present invention will be explained using the drawings.

As shown in Figure 1 (a), first, the ground 11 is excavated,
A space 12 is provided. 13 is a release port.

As shown in FIG. 1(b), expandable thermoplastic resin particles are supplied into the tank of a continuous pre-foaming machine 22 connected to a small boiler 21 placed on the bed of a truck 20, and 0.1~
5kg/cm”G (0 for expandable polystyrene particles)
．． 1 to 0.5 kg/cm"G, 0.5 to 2 kg/kg/cm2G for expandable polyethylene particles, 2.5 to 5 kg/cm2G for expandable polypropylene particles
) of the foamable thermoplastic resin particles.
The particles are expanded 80 times to obtain pre-expanded particles 30, which are filled into the space 12 of the excavated ground 11. As shown in FIGS. 3(a) and 3(b), a steam supply pipe 40 with a blind end 41 and holes 42 of 0.8 to 2 mmφ provided in a staggered manner at a pitch of 10 on the peripheral wall of the pipe is pre-foamed. Particle 30.30・
... is inserted through the hole 51 of the plywood plate 50 that covers the open opening into the space 12 filled with [see Fig. 1 (c)].

The plywood board 50 may be a metal plate. When this plate is light, weights 52, 52, etc. are placed on the plate to prevent the plate 50 from floating up when the pre-expanded particles expand.

The means for preventing the pre-expanded particles 30, 30... from floating during heating does not necessarily need to be a plate.

As shown in FIG. 2, pre-expanded particles 30, 30. . . . Place a perforated resin film, net, paper, etc. 60 on top, insert the steam supply pipe 40 into the space, and then cover the resin film 60 with earth, sand, gravel, etc. 50'. The reason why resin film or net) 60 is used is that dirt enters the space between the pre-foamed particles (about 33.3% when the particles are perfectly spherical, but normally exists about 30 to 40% by volume), causing foaming. This is to prevent the fusion of the particles that have been applied to each other from being inhibited.

The weight of the plate and soil covering to prevent the pre-foamed particles from lifting during foam molding varies depending on the amount of foaming agent remaining in the pre-foamed particles and the height of the resulting foamed product, but is usually 500 kg.
It is sufficient that a load of /m2 or more is applied to the particles.

Open the opening 13 on the pre-expanded particles to a plate, earth and sand, etc. 50°50'
Once covered, connect the steam supply pipe 40 to the pipe 23 of the boiler 21 with a hose 25, etc., and open the valve 24 to
．． Steam (water vapor) of 1 to 5 kg/cm"G is supplied, and the steam is ejected from the holes 42, 42 of the pipe to thermally expand and fuse the pre-expanded particles to form a foamed molded product 30'. At this time, the steam escapes through the voids in the earth and sand in the ground 11, so the pressure in the space 12 is not as high as the one shown in the left, and there is no concern that the plates or covering soil will fly up.The steam supply time is 0.5 to 3 minutes is sufficient.

After manufacturing the foam molded body 30', the foam molded body 30' together with the steam supply pipe 40 is covered with earth and sand 7 as shown in FIG. 1(d).
0, a concrete floor plate 80 is placed on top of the asphalt pavement 90, and a road is obtained.

Further, the steam supply pipe 40 is removed from the foamed molded body 30', covered with soil 70, and used as a ground or a parking lot.

The present invention can also be used as a method for burying the quarry remains (space 12) of Oya stone or limestone that have already been quarried (earth excavated) with the foamed molded body 30'. The opening 13 of the quarry site 12 is shown in Figure 4 (
If the ground 11 is lying on its side as shown in b), after foam molding, remove the steam supply pipe 40 from the molded body 30',
A retaining wall 80 is installed and filled with earth and sand and crushed stone 70 [Figure 4 (b)].

As expandable thermoplastic resin particles, butane, heptane,
Polystyrene, polyethylene, polypropylene, ABS, containing 8 to 30% by weight of volatile blowing agents such as Freon,
A material such as nylon having a particle size of 0.5 to 5 anus is used.

The resin film 60 is made of polyethylene, polypropylene, high impact polystyrene, etc. with a thickness of 20 to 1
,000 microns, and as the net, a polypropylene flat yarn woven fabric with a fine weave, a polyester nonwoven fabric, a polyvinyl chloride woven fabric, a wire mesh, etc. are used.

Example 1 Soil with a density of 1.47 g/cvn3 was excavated and
A recess with a width of 1,600 nm and a depth of 650 mm was provided.

Using a small boiler (length 2000 mm, width 2500 mm, height 2000 mm) on the bed of a truck and a continuous prefoaming machine, a particle size of 1.5 m containing 8% by weight of butane was used.
Pre-expanded polystyrene particles having a bulk density of 20 g/l were obtained by foaming 50 times the expandable polystyrene particles with 0.2 kg/cm 2 G of steam, and these were filled into the recess to a depth of 550 mm.

Next, a wall thickness of 30 microns was placed on top of the filled foam particles.
Cover with polystyrene film with 2 inch holes;
Furthermore, the end of the 2-inch pipe is blinded, and a 10 m
Holes of 1III1φ at m pitch intervals.

A steam supply pipe with a large number of holes (see Figure 3 (a)) was guided through the film holes into the space filled with pre-expanded particles.

Next, after covering the film with earth and sand to a height of 100 kg (load: 190 kg/m2), connect the steam supply pipe and boiler pipe with a hose, open the valve, and inject 0.5 kg.
g/cm" steam was supplied for 2 minutes to thermally expand and fuse the pre-expanded particles to obtain a foamed molded product (degree of fusion: 15%, compressive strength: 1.1 kg/cm2, density: 20 g/cm). .

Implementation 0.2 The amount of pre-expanded particles filled in the recess was adjusted to a depth of 650 mm.
In addition, instead of the resin film and soil covering, a plywood board with a wall thickness of 18 mm and 8 holes of 23 mm diameter and two weights weighing 100 kg were used [see Figure 1 (c)] (Load 2
A foamed molded article (density 20 g/l, degree of fusion 15%, compressive strength 1.15 kg/cm") was produced in the same manner as in Example 1, except that 00 kg/m") was used.

(Effects) According to the method of the present invention, it is possible to easily obtain a foam molded product from expandable resin particles.
cm” or more).

[Brief explanation of drawings]

Figures 1 (a), (b), (c), and (d) are cross-sectional views showing steps for implementing the present invention, Figure 2 is a cross-sectional view showing another embodiment, and Figure 3 (a) is A perspective view of the steam supply pipe, Figure 3 (B) is a partial enlarged view of the tip of the steam supply pipe, Figures 4 (A) and (B) are cross-sectional views showing how to fill the space in the quarry site, and Figure 3 (B) is a partial enlarged view of the tip of the steam supply pipe. Figures 5 (a), (b), and (c) are perspective views showing construction examples of the conventional landfill EPS civil engineering method.

Claims (1)

[Claims] 1) After excavating a construction site in the ground into a desired shape, 10 to 80 particles of expandable thermoplastic resin are poured into the excavation area from the opening.
Fill the excavated space with pre-foamed thermoplastic resin particles that have been expanded to double their original size, then cover the open mouth of the excavated area with a board, earth and sand, etc., and then foam the pre-foamed thermoplastic resin particles by heating them with steam. , a method for manufacturing a foam at a construction site, characterized by forming a foam molded product by fusing particles together. 2) The pre-foamed thermoplastic resin particles are heated by placing a pipe having a large number of steam holes in the peripheral wall between the pre-foamed thermoplastic resin particles and introducing steam into the pipe. Method described.