JP2007277912A - Burial mould - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a burial mould having flexural strength and compressive strength superior in durability against erosion and water pressure by water, superior in anti-corrosiveness, capable of thinning the cross-sectional thickness more than a cement concrete burial mould, and particularly effective in a marine or river civil engineering/construction structure. <P>SOLUTION: This burial mould has an inside surface on the side for placing concrete and an outside surface opposed to this inside surface. The burial mould is formed of a modified sulfur solid body on the outside including at least the outside surface, and is characterized in that the solid body includes fine powder having the particle size of 1 mm or less and metallic fiber. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an embedded formwork, and more particularly to a high-strength embedded formwork that is effective for marine or river civil engineering / construction structures and has excellent durability against water erosion and water pressure, and corrosion resistance.

The embedded formwork works as a formwork when placing concrete in the construction of structures such as walls, columns, and beams, and is used as a part of the structure without dismantling the formwork after concrete placement. It is well known as a formwork that combines plate shapes.
In such an embedded formwork, excellent mechanical strength such as compressive strength and bending strength, anticorrosion properties, etc. are desired so that it can be maintained as a structure, and further, peeling from concrete can be suppressed. Unity is also required.
Conventionally, cement concrete has been mainly used as a material constituting the embedded formwork. However, since the anticorrosion property of cement concrete may become a problem depending on the construction site or the like, a resin layer is also provided by a coating lining method, a sheet lining method, or the like. In addition, a resin-made buried form having excellent corrosion resistance is also known.
Furthermore, Patent Document 1 proposes a buried form using a sulfur solidified body panel.
However, in this document, a specific material or the like is not studied as the sulfur solidified panel.
Japanese Patent Laying-Open No. 2005-90016

  The problem of the present invention is that it has bending strength, compressive strength, etc. excellent in durability against water erosion, water pressure, etc., and also has excellent corrosion resistance, etc. In particular, it is an object of the present invention to provide a buried formwork effective for use in ocean or river civil engineering / construction structures.

  According to the present invention, an embedded form having an inner surface on which concrete is placed and an outer surface opposite to the inner surface, the outer side including at least the outer surface is formed by the modified sulfur solidified body, An embedded form is provided in which the solidified body includes modified sulfur, fine powder having a particle diameter of 1 mm or less, and metal fibers.

  In the embedded form of the present invention, the outer side including at least the outer surface is formed by the modified sulfur solidified body including modified sulfur, fine powder having a particle diameter of 1 mm or less, and metal fiber. It has excellent bending strength and compressive strength against durability and water pressure, etc., and it can prevent salt damage, corrosion resistance, etc. due to its excellent water and acid resistance by modified sulfur. The cross-sectional thickness can be reduced as compared with a buried mold. Therefore, it is particularly useful as a buried form for an ocean or river civil engineering / construction structure.

Hereinafter, the present invention will be described in more detail.
The embedded form of the present invention is a well-known embedded mold having a plate shape, a box shape, or a shape in which the inside of the box shape is partitioned, having an inner surface on which concrete is placed and an outer surface opposite to the inner surface. It has the form of a frame, and the outer side including at least the outer surface is formed of the modified sulfur solidified body. Preferably, substantially the entire formwork is formed of the modified sulfur solidified body, and a member or the like for improving adhesiveness with concrete described later may be provided on the inner surface side. The cross-sectional thickness of the embedded mold is usually 30 to 200 mm, preferably 50 to 100 mm.

The modified sulfur solidified body provided in the embedded form of the present invention contains modified sulfur, specific fine powder, and metal fibers as essential components.
The modified sulfur is, for example, a natural product, or sulfur produced by desulfurization of petroleum or natural gas, polymerized with a sulfur modifier, and is a reaction product of sulfur and the sulfur modifier.

Examples of the sulfur modifier include olefinic hydrocarbons or diolefinic hydrocarbons having 4 to 20 carbon atoms, specifically, cyclic olefinic hydrocarbons such as limonene and pinene, styrene, vinyltoluene, methylstyrene, and the like. Aromatic hydrocarbons, dicyclopentadiene and oligomers thereof, cyclopentadiene, tetrahydroindene, vinylcyclohexene, vinyl norbornene, ethylidene norbornene, and diene hydrocarbons such as cyclooctadiene, or a mixture of two or more thereof. .
The modified sulfur can be obtained by melt-mixing sulfur and a sulfur modifier. Under the present circumstances, the usage-amount of a sulfur modifier is 0.1-20 mass% normally with respect to the total amount of sulfur and a sulfur modifier, and the ratio of 1.0-10 mass% is especially preferable.
If the ratio of the sulfur modifier is less than 0.1% by mass, sulfur cannot be sufficiently modified, and desired mechanical strength and corrosion resistance may not be exhibited.

The specific fine powder is a fine powder having a particle size of 1 mm or less, preferably 100 μm or less. For example, natural stone powder, sand, silica sand, ferronickel slag, coal ash, fuel incineration ash, electrostatic dust ash, silica fume , One or more fine powders selected from the group consisting of alumina powder, quartz powder, activated carbon, shell powder, glass powder and the like.
In addition to the fine powder, an aggregate having a particle size of 25 mm or less may be mixed. In this case, the particle size is preferably 1/3 or less of the cross-sectional thickness of the embedded mold. Examples of such aggregates include one or more selected from the group consisting of natural stone, sand, gravel, rubble, silica sand, ferronickel slag, blast furnace slag, molten slag, shells, and the like.
As fine powder and aggregate, in order to further improve the corrosion resistance of the embedded formwork, at least Ca and Si are contained, and Ca, Si, and Al in the fine powder are converted into oxides of CaO / (SiO ₂ + Al ₂ O ₃ ) It is preferable to use inorganic fine powder having a mass ratio of 0.2 or less. The ratio of CaO / (SiO ₂ + Al ₂ O ₃ ) in the fine powder is as follows: the Ca amount is converted to CaO, the Si amount is converted to SiO ₂ , and the Al amount is converted to Al ₂ O _3. It can be determined by the ratio. At this time, Al is not necessarily included.
Examples of such fine powder include one or more fine powders mainly composed of silica components such as coal ash, silica sand, silica fume, quartz powder, sand, glass powder, and electrostatic dust collection ash. .

  The content ratio of the fine powder is usually 10 to 500 parts by mass, particularly 30 to 100 parts by mass with respect to 100 parts by mass of the modified sulfur. Moreover, when mixing aggregate, it is 10-500 mass parts normally with respect to 100 mass parts of mixture of modified sulfur and a fine powder, Especially 100-200 mass parts is desirable.

The metal fiber is important as a component capable of increasing the bending strength of the modified sulfur solidified body, and in particular, improving the durability against water erosion or water pressure in the ocean or rivers.
Examples of the metal fiber include steel fiber, stainless steel fiber, and amorphous fiber, and examples of the shape include a straight shape, a curved shape, a mesh shape, a dock bone shape, and the like. It is preferable to use a metal fiber having a hook shape or a bone shape having a portion having a large diameter, that is, a so-called dock bone shape.
The diameter of the metal fiber is preferably about 0.1 to 3.0 mm, and the length is usually preferably about 5 to 50 mm. However, the diameter does not need to be constant as in the case of a metal fiber having a dockbone shape.
The content of the metal fiber is preferably 0.1 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and particularly preferably 1 to 5 parts by mass with respect to 100 parts by mass of the modified sulfur. If the metal fiber content is less than 0.1 parts by mass, the desired mechanical strength may not be improved, and if it exceeds 20 parts by mass, the economics of the mold will be reduced.

In the modified sulfur solidified body, in addition to the modified sulfur, fine powder, metal fiber, and aggregate, within a range that does not impair the desired object of the present invention, for example, organic fibers, flaky particles, and the like An appropriate amount of additives can also be contained.
Examples of the organic fiber include vinylon fiber, polypropylene fiber, polyethylene fiber, aramid fiber, carbon fiber, and a mixture thereof.

The embedded form of the present invention can be substantially formed of the above-described modified sulfur solidified body. For example, a known slate board, fiber reinforced gypsum board, calcium silicate board, fiber reinforced cement board, heat resistant plastic board , an FRP plate, allowable bending stress of 135 kgf / cm ² cm or more, a Young's modulus 70000kgf / cm ² or more, the outer layer of the substrate having the adhesion 1.0 kgf / cm ² or more and the modified sulfur concrete substance A mold having a layer of the modified sulfur solidified body may be used.

In the embedded form of the present invention, the production of the modified sulfur solidified product is performed by, for example, mixing the modified sulfur melt with the raw material containing the specific fine powder and the metal fiber at 120 to 160 ° C. It can be obtained by introducing into a form of the form and solidifying by cooling while giving vibration or the like.
The modified sulfur melt is obtained by melting and mixing sulfur and a sulfur modifier in a range of 120 to 160 ° C. using various known warmable mixers, for example, to sufficiently reform sulfur. The viscosity at 140 ° C. is usually 0.05 to 1.0 Pa · s, preferably 0.05 to 0.5 Pa · s.
Mixing of raw materials including modified sulfur melt, fine powder and metal fiber, heat the fine powder and metal fiber to about 120-155 ° C in advance, and if necessary, modify sulfur melt together with other materials such as aggregate It can be carried out by mixing the product at a desired temperature that maintains a molten state.

In the embedded form of the present invention, the inner surface on the side on which the concrete is placed is provided with an uneven shape and / or on the inner surface in order to improve the adhesion between the placed concrete and the embedded form. In addition to providing a non-woven fabric, a plurality of anchor materials can be provided so as to project integrally.
For example, when the inner side including the inner surface is also formed of a modified sulfur solidified body, the inner surface including the inner surface is formed with a modified sulfur solidified body. A method of fixing crushed stone or the like to the inner surface during cooling and solidification of the body, a method of pressing a metal mesh or the like against the inner surface during the cooling and solidification, and unevenness on the surface of the mold when molding and solidifying the modified sulfur solidified body. And the like.

EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited to these.
Example 1
50 kg of solid sulfur was put in a closed stirring kneader, melted at 120 ° C., and maintained at 130 ° C. The viscosity at this time was measured with a B-type viscometer and found to be 0.018 Pa · s. Subsequently, 2 kg of tetrahydroindene was slowly added and stirred. The reaction started and the temperature of the system reached about 145 ° C. due to the exothermic reaction. Thereafter, it was confirmed that the temperature increase was completed, and the viscosity of the reaction system at that time was measured and found to be about 0.1 Pa · s.
Next, in the above state, 25 kg of coal ash having a particle diameter of 1 mm or less, 225 kg of ferronickel slag having a particle diameter of 0.3 to 5.0 mm, and a stainless steel dock bone type metal fiber (length 3.5 cm, center fiber diameter 1 mm) The material preheated to 140 ° C. consisting of 15 kg) was started by mixing. The temperature of the mixture was controlled at 150 ° C. and mixed for 20 minutes. After completion of mixing, the metal formwork provided with a jacket-type heater for a buried formwork having a length of 1200 mm, a width of 2000 mm, and a thickness of 50 mm, in which the obtained modified sulfur-containing material in a molten state was previously heated to 140 ° C. Introduced. Before the introduction, the formwork jacket was kept at about 140 ° C. with steam. During the introduction, the formwork was vibrated.
After introducing the modified sulfur-containing material, the steam of the mold jacket was removed, and after cooling, the mold was removed to produce an embedded mold plate.

When the compressive strength and bending strength of the resulting embedded formwork plate were measured according to JIS A1108, the compressive strength was 80 N / mm ² and the bending strength was 14 N / mm ² .
For comparison, using a metal mold of the same form, water of 24 kg of water, 80 kg of cement, 160 kg of fine aggregate, 0.8 kg of admixture, and 22.5 kg of dog bone type metal fiber is added to the mold. A concrete composition having a cement ratio of about 30% was introduced and cured for 28 days to produce an embedded formwork plate made of cement concrete. Compressive strength of the resulting mold plate is 20 N / mm ^2, was flexural strength 12N / mm ^2.
The wear resistance of the mold plate produced in the above example and the mold plate produced for comparison was measured by ASTM C779-82A. As a result, the form plate of Example 1 showed about 30% higher abrasion resistance than the cement concrete form plate for comparison.

Claims (7)

An embedded formwork having an inner surface on which concrete is placed and an outer surface facing the inner surface;
An embedded form, wherein an outer side including at least an outer surface is formed of a modified sulfur solidified body, and the solidified body includes modified sulfur, fine powder having a particle diameter of 1 mm or less, and metal fibers.   The embedding mold according to claim 1, wherein the modified sulfur solidified body contains 100 to 500 parts by mass of fine powder having a particle diameter of 1 mm or less and 0.1 to 20 parts by mass of metal fibers with respect to 100 parts by mass of the modified sulfur. frame.   The fine powder is selected from the group consisting of natural stone powder, sand, quartz sand, ferronickel slag, coal ash, fuel incineration ash, electrostatic dust ash, silica fume, alumina powder, quartz powder, activated carbon, shell powder and glass powder. The embedded form according to claim 1 or 2, comprising at least one kind.   The embedded form according to any one of claims 1 to 3, wherein the metal fiber has a linear shape, a curved shape, a mesh shape, or a dock bone shape, and has a length of 5 to 50 mm.   The embedding formwork according to any one of claims 1 to 4, which has an uneven shape and / or a non-woven fabric on the inner surface on which concrete is placed.   The embedded form according to any one of claims 1 to 4, wherein a plurality of anchor members are integrally projected on the inner surface on the side where the concrete is placed.   The embedded formwork according to any one of claims 1 to 6, wherein the formwork is used for a marine or river civil engineering / construction structure.