JPH045321A - Civil engineering work method using foaming resin - Google Patents

Abstract

PURPOSE:To construct a uniform resin foaming material ground by forming a chamber of the ground and a porous plate unit, on which resin beads are scattered, and supplying heated gas to this chamber to foam the resin beads through the porous plate unit. CONSTITUTION:A chamber 5 is formed between the ground surface 3 and a plate unit 4 after driving piles 6 into the lower side ground surface of a slope 2 to arrange the ventilating plate unit 4 of predetermined height on the ground surface, and further side surfaces of the chamber 5 are covered with a form 8. A bolier 11 is connected to the chamber 5 through a gas supply pipe 9 and a pump 10. Material of porous ceramics or the like is used for the plate unit 4. Next, resin beads 7 are scattered in uniform thickness on the plate unit 4. Successively, the beads 7 are heated and foamed through a porous gap of the plate unit 4 by supplying heated gas to the chamber 5 through the boiler 11. In this way, a uniform foaming material can be obtained by uniformly heating the beads 7.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a civil engineering method for foaming a foamable resin into a required shape on site to obtain a resin foam with a uniform foamed state and compressive strength when forming an artificial ground embankment 9, widening a road, etc.

[Prior art 1] Attempts have been made to take advantage of the lightweight nature of foamed resin to fill depressions or make it part of artificial ground. These foam blocks are piled up on the original ground that is to be embanked, and the surface is finished with concrete floor plates, wall protection materials, etc. Additionally, reinforcing materials such as reinforcing bars are placed inside to improve structural strength. When forming an artificial ground by stacking foams in this manner, misalignment is likely to occur between the foam blocks. Therefore,
Utility Model Application No. 63-81941. In Japanese Utility Model Application Publication No. 63-81942, etc., in order to eliminate this misalignment, unevenness is formed on the surface of the foam block,
It is introduced that these irregularities can be interlocked. However, the method of transporting foam blocks that have been foamed in a factory to the site and stacking them into a predetermined shape requires time and effort to transport and handle. For example, a large block of about 2XIX 0.5 m is used as this type of block, but such a large block requires manpower to transport, although it is lightweight. Furthermore, the transportation is essentially like transporting air, which is wasteful. Moreover, as the blocks become larger, it becomes necessary to flatten the original ground on which work such as embankment is to be performed so that no gaps are formed between the blocks and the laid blocks. Furthermore, Japanese Patent Application Laid-open No. 47-19617 discloses that after spraying an unfoamed resin such as urethane, vinyl chloride, or styrene onto a depression or roadbed, a foaming reaction is caused to fill the depression. ing. However, this publication does not specifically teach how to foam the resin. By the way, if the resin is simply foamed, the surface of the resin body after foaming often does not have the required contour due to non-uniform foaming or the like. In addition, when foaming occurs at the free interface,
The surface strength of the foam is insufficient, and dents are likely to occur when treading pressure is applied. Problem to be Solved by the Invention 1 The present inventors have developed a method for forming artificial ground with the required strength while taking advantage of on-site construction. We have developed a method to construct artificial ground by scattering resin beads and foaming the resin beads with heated gas. By the way, when building a foundation by foaming resin beads, non-uniform foaming of the resin beads tends to occur. As a result, defects such as unevenness on the surface of the foamed resin body and internal cavities occur. It is presumed that such defects are caused by fluctuations in the foaming atmosphere of the resin beads. Therefore, the purpose of the present invention is to uniformly foam the resin beads by uniformly bringing heated gas into contact with the resin beads, and to construct a base made of resin foam that has a uniform foam structure and compressive strength. shall be. [Means for solving the problem 1] In order to achieve this objective, the civil engineering method of the present invention arranges a plate made of a porous material or a plate with many pores bored above the original ground. forming a chamber between the original ground and the plate body, and scattering resin beads on the plate body,
A mold is placed above the beads with a space therebetween, and heated gas supplied to the chamber is passed through the plate and brought into contact with the resin beads to heat and foam them. [Operation] Heated gas such as water vapor supplied to the chamber. The resin beads are supplied through a plate made of porous material or a plate with a large number of pores. At this time, the heated gas supplied from a boiler etc. through the air supply gap is once released from the supply pressure in the chamber, and then directed to the resin beads via the porous material or pores of the plate. It flows. Therefore, the heated gas contacts the resin beads with a uniform flow rate distribution over the entire surface of the plate, and the foaming of the resin beads is performed uniformly over the entire surface. Therefore, local occurrence of a foaming reaction is suppressed, and a resin foam having a uniform foamed state can be obtained.

【Example】

Hereinafter, the present invention will be specifically described by way of an example applied to an embankment on a slope, with reference to the drawings. In this embodiment, as shown in FIG. 1, a predetermined embankment is placed on a slope 2 of the original ground 1. A breathable plate 4 is arranged above the lower ground 3, and the lower ground 3
A chamber 5 is formed between the plate body 4 and the plate body 4. The air permeable plate 4 is made of, for example, porous sintered ceramics, foamed concrete, a metal plate with a large number of pores, or the like. This breathable plate 4 is supported by stakes 5 driven into the lower ground 3 and maintained at a predetermined height from the lower ground 3. An appropriate amount of resin beads 7 are spread on the air-permeable plate 4 with an even thickness. Various resin beads 7 are known, such as foamable styrene resin, urethane resin, and urea resin. For example, styrene resin is used in a wide range of fields as a material for resin foam.
It expands at a foaming ratio of about 35 to 45 times. Therefore, the formwork 8 is placed at a position that takes into account the volume after foaming. It is preferable that the internal volume of the mold 8 is slightly smaller than the volume obtained when the resin beads 7 are foamed in a free state. As a result, at the final stage of foaming the resin beads, a restraining force, ie, pressure, is applied by the mold 8, and the surface layer of the resin foam becomes dense. An air supply pipe 9 opens into the chamber 5 . This air supply pipe 9 is connected to a boiler 11 via an air supply pump 10.
connected to a heated gas source such as Next, a procedure for forming a ground using resin foam using this device will be explained. Styrene resin with an average particle size of 0.9 mm was used as the resin beads. As shown in Figure 2, this resin starts a foaming reaction depending on the temperature and time, and at the end of the reaction it expands into a foam with an expansion ratio of about 30 to 45 times, and the density after foaming is about 0.015 g. /cm3. As the inclined surface 2, one with a cross-sectional area of 1 m x 1 m and a step difference of 80 cm was prepared. The lower ground 3 of this slope 2
A porous ceramic plate 4 with a thickness of 5 cm was placed at a height of 10 cm from the base. Then, a chamber 5 formed between the lower ground 3 and the porous ceramic plate 4 has an inner diameter of 30 m.
The air supply pipe 9 of m was opened. Note that the porous ceramic plate 4 was supported by stakes 6 driven into the lower ground 3 at a depth of 4Q cm. And porous ceramic plate 4
Resin beads 5 were sprinkled on top to a thickness of 23 mm. In this state, the temperature from the boiler 11 to the air supply pipe 9 is 100°C.
of water vapor was supplied at a flow rate of 0.1 m3 per minute. After once expanding in the chamber 5, the water vapor passed through the porous ceramic plate 4 and came into contact with the resin beads 7 as a flow with a uniform flow rate distribution. 15 minutes of water vapor injection
After continuing for several minutes, the resin beads 5 expanded to a height of 65 cm from the surface of the porous ceramic plate 4. The resin beads 5 continue to foam and try to expand, but their outer shells are restrained by the formwork 8. Therefore, this expanding force acts on the resin foam as a reaction force, and the surface of the resin foam becomes dense. Next, the formwork 8 is removed, the formed resin foam is taken out from the inclined surface 2, and cut vertically and horizontally.
The foaming state inside was observed. As a result, it was found that the foamed structure was substantially uniform in both directions. In addition, when a test piece was cut out from this foam and its compressive strength was measured, the compressive stress value when applying a compressive strain of 4% was 1.5 to 2.
．． It was in the range of 0 kg/Cm2. From this, the average pedal pressure applied when the vehicle is running is 0.5kg/cm2.
It can be seen that ground with sufficiently greater strength has been obtained. After a test in which a moving load of 100 kg was repeatedly applied to this resin foam for 10 hours, the surface condition of the resin foam was examined, and no defects such as depressions were detected. On the other hand, the resin beads 5 are not provided with the porous ceramic plate 4.
When heating and foaming was carried out by directly blowing out water vapor, the resulting resin foams had uneven foaming states, and their compressive strengths varied widely, ranging from 0.5 to 2.5 kg/cm2. This is considered to be due to the fact that the flow rate of the supplied water vapor varies with respect to the gas blowing direction and that the resistance of the gas passage formed between the resin beads 7 varies. Due to the non-uniformity of the foamed state and the variation in compressive strength, when moving loads were similarly repeatedly applied to the obtained resin foam, localized areas were detected. In the above embodiments, the embankment of the slope 2 is explained as an example, but the present invention can also be applied to embankment of a depression, expansion of road width, etc. by a similar method. In addition, by further providing a breathable plate on top of the formed resin foam and heating and foaming the resin beads again on the breathable plate, the resin foam can be stacked in multiple layers and deep depressions can be created. It is also possible to carry out embankments on slopes with large differences in level, road sides, etc. Effects of the Invention 1 As explained above, in the present invention, when constructing the ground by foaming resin beads on-site, heated gas such as water vapor is applied to a porous material plate or a large number of fine particles. The resin beads are supplied through a plate with holes. This ensures uniform contact between the resin beads and the heated gas.
After foaming, the inside and outside of the resin will be in a substantially -like foamed state, and the compressive strength will not locally decrease. In this way, according to the present invention, it is possible to easily construct a ground having sufficient strength to withstand treading pressure.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining an embodiment in which the present invention is applied to the creation of an inclined surface, and FIG. 2 is a graph showing the foaming state in relation to temperature and time. 1...Original ground 2...Sloped surface 3...Lower ground 4...Breathable plate 5...Chamber
6...Pile 7...Resin beads 8...Formwork 9...Air supply pipe 10...Air supply pump 11...Boiler rule ρ

Claims (1)

[Claims] A plate made of a porous material or a plate with a large number of pores is arranged above the original ground to form a chamber between the original ground and the plate, and a chamber is formed above the plate. Resin beads are dispersed, a formwork is placed above the beads with a space therebetween, and heated gas supplied to the chamber is passed through the plate and brought into contact with the resin beads to cause heating and foaming. A civil engineering method that uses foamed resin.