JPH0486201A - Fiber reinforced concrete formed article - Google Patents

Abstract

PURPOSE:To make it possible to manufacture fiber reinforced concrete formed article, which takes the place of low cost asbestos cement formed article, by a method wherein carpet scraps, which are developed by cutting off the piles of carpet, are mixed with the concrete of the formed article. CONSTITUTION:In a carpet mill, carpet scraps, which are developed by cutting the tip of the piles, are gathered. The carpet scraps together with cement, aggregate and necessary admixture are dry-mixed while they are in powdered state. While being gradually added with water, the resultant mixture is fully kneaded with a mixer so as to be charged in the hopper 2a of an extruder 2 in order to be extruded through an extruding die 2b into the predetermined shape with an extruder screw and then cut in the longer direction of the shape with a cutter 2c. Since fibers for carpet are dispersed in concrete, the resultant concrete formed article has high bend-fracture rate and tensile strength, resulting in obtaining concrete product having high toughness, tensile strength, bending strength and shearing strength and being used as effective and proper substitute for asbestos cement product.

Description

Detailed Description of the Invention "Field of Industrial Application" The present invention relates to molded products formed by extrusion molding of concrete, and is particularly used in textile (carpet) factories for making rugs, carpets, etc. This invention relates to a fiber-reinforced concrete molded product that uses carpet waste generated during cutting as fiber-reinforced material.

[Prior art] In general, fiber reinforced concrete is obtained by uniformly dispersing short fibrous materials in mortar or concrete, and the tensile strength is increased by the fibrous materials dispersed in the concrete. It improves the brittleness of concrete by increasing its crack strength and toughness.

Such fiber-reinforced concrete differs not only in its characteristics but also in its manufacturing method and application field, depending on the type of fibrous material used. For example, as the fibrous material, steel fibers and glass fibers are generally used because the higher the Young's modulus, the greater the crack arresting ability. On the other hand, synthetic fibers such as nylon and polypropylene have a small Young's modulus (less than 1/10 that of concrete and about 1/1 that of steel).
/100 or less), it cannot be expected to increase the crack restraining effect, etc., but it is effective for improving impact resistance because of its large elongation.

Conventionally, concrete using steel fibers and glass fibers among these fibrous materials has been used practically in various fields because of its superior properties compared to plain concrete, and synthetic materials such as nylon and polypropylene fibers have Since fibers can be used to make composite materials with excellent toughness, their use as a substitute for asbestos in asbestos-cement molded products is being considered.

[Problems to be Solved by the Invention] The present invention aims to solve the following problems in the prior art described above.

In other words, in recent years, the carcinogenicity of asbestos has become a problem, as well as problems in the supply of asbestos and health problems caused by asbestos.Therefore, there has been a demand for the development of substitutes for asbestos using fibrous feathers.For example, nylon, Synthetic fibers such as polypropylene fibers are still expensive,
The problem is that it is not a sufficient substitute for asbestos.

The present invention has been proposed in view of the above circumstances, and its purpose is to provide a fiber-reinforced concrete molded product that can replace asbestos cement molded products at a low cost.

[Means for Solving the Problems] In order to achieve the above object, in the present invention, concrete is put into the hopper of an extrusion molding machine while it is still extrudable, and while being extruded by a screw for extrusion molding. A concrete molded product that is formed by extruding it into a predetermined shape with a die and cutting it in the length direction, and in order to align the top surface or edge of the woven carpet in the concrete of the molded product. It is made by mixing in carpet debris that is generated when cutting the pile part of the carpet with a cutter.

Further, as the carpet waste, it is preferable to use the carpet waste generated by shearing the pile portion with a shearing machine for shearing.

[Function] As mentioned above, the fiber-reinforced concrete molded product of the present invention has carpet waste containing a complex mixture of various types of fibers dispersed inside the molded product extruded into a predetermined shape by concrete extrusion. As a result, the concrete product has high toughness and high tensile strength, flexural strength, and shear strength, making it an effective and suitable substitute for asbestos cement products. Become something.

"Example" Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of the fiber-reinforced concrete molded product according to the present invention, and in the same figure, the molded product indicated by the symbol 1 as a whole is applied as a concrete spacer, Although it cannot be seen in the drawing, the concrete that forms the main part of this spacer is mixed with carpet debris that is generated when the pile part of the carpet is cut with a cutter to align the top surface or edges of the woven carpet. ing.

Carpet waste, which is the main material of this fiber-reinforced concrete molded product, is collected from the carpet waste produced by cutting the ends of the threads (pile part) on the carpet surface at carpet factories. Anything that can be used can be used, and there are no particular restrictions on its type or properties. Note that, since a shearing machine for shearing is usually used to cut (shear) the surface of the pile portion, the carpet waste is mainly composed of the sheared by the cutter of this shearing machine.

In addition, for the pile part of carpets, yarns such as acrylic, nylon, polyester, wool, and rayon made by spinning short fibers into yarns, or yarns made from continuous filament yarns such as nylon and polypropylene are used. Therefore, the carpet waste collected by cutting the tip of the pile varies depending on the fibers that make up the carpet, but in carpet factories, it is usually a collection of these fibers intertwined in the form of waste.

To explain in more detail, carpets are meant for humans to live in, so they are often planted with piles in a standing pile to give them an attractive appearance and a soft springy texture. The denier of the single fibers that make up the pile of carpets is thick (
6-30d) Furthermore, synthetic fibers are made to have an irregular cross section to improve the compression recovery of the pile.

Therefore, the carpet waste generated by cutting the tip of such a pile part has a thick single fiber denier (6 to 30 d), and synthetic fibers have an irregular cross section.

In particular, synthetic fibers such as nylon and polyester made using the melt-spinning method are easy to create into desired cross-sectional shapes, such as trilobal cross-sections with an emphasis on recovery, and polygonal cross-sections with a resistive effect. .

In addition, carpet face yarns are made of spun yarn or bulky filament yarn, and both yarns are crimped to improve their appearance, so the carpet waste is also crimped. Needless to say, it is.

In addition, since the face yarn of spun yarn is composed of different fiber blends such as wool and nylon blends, different denier blends, and different colored cotton mixes, these carpet wastes are also
In the end, it is made up of different fiber blends, different denyl blends, and different colored cotton mixes.

To obtain a concrete molded product (concrete spacer) using concrete reinforced with fibers from such carpet waste, an extrusion molding machine 2 as shown in FIG. 2 is used, for example.

Specifically, at a carpet factory, the carpet waste generated by cutting the tip of the pile section is collected, and the carpet waste is dry kneaded as a powder with cement, aggregate, and necessary admixtures, and water is gradually added to this. In addition to
The mixture is kneaded with a mixed mixer, put into a popper 2a of an extrusion molding machine 2, and extruded with an extrusion screw and extruded into a predetermined shape (the shape of a concrete spacer in the illustrated example) with an extrusion molding die 2b. cutter 2
Just pray in the length direction using c.

The concrete molded product obtained in this way has high values of flexural rupture modulus and tensile strength because the carpet fibers are contained in the concrete in a dispersed state, and as a result, it has high toughness and tensile strength. The concrete product has high bending strength and shear strength, making it an effective and suitable substitute for asbestos cement products.

In particular, in the present invention, by using carpet scraps, which are industrial waste normally disposed of from carpet factories, this can be effectively reused, so the cost of fibrous materials can be kept low and the cost can be reduced. It has the advantage of being able to provide inexpensive fiber-reinforced concrete products.

In addition, in the present invention, carpet scraps are uniformly dispersed and mixed into the concrete to be put into the potspar, and the molded product is manufactured by extrusion molding, so it is possible to obtain a high-quality fiber-reinforced concrete molded product. can.

It goes without saying that the present invention is not limited to the above-mentioned embodiments, and can be applied to any product as long as it is an extrusion molded product.

In addition, the composition of the carpet waste may be considered in the same manner as the conventional mixture of asbestos. For example, by mixing 0.5 to 10 wt% of carpet waste with cement, it is possible to create a board that is used as asbestos slate. It can provide similar or better performance.

Next, the present invention will be explained in more detail by showing test examples of the fiber-reinforced concrete molded product according to the present invention.

"Test Example 1" Add 1wt% of carpet waste (carpet fiber) to ordinary Portland cement, silica sand, and various admixtures.
, 3 wt%, 5 wt%, and 7 wt%, respectively, were dry-kneaded in a mixer, and then kneaded in a mixed mixer while gradually adding water. While extruding with a screw, it was extruded through an extrusion molding die (40 mm x 40 mm and 50 mm diameter), and cut into predetermined lengths of 160 mm and 100 mm with a cutter to obtain two types of specimens (40 mm x 40 mm x 160 mm square column and 50 mm φ x 100 mm cylinder). Created.

In addition, if carpet waste is not added (0w
t%) was also prepared using the same manufacturing method.

Then, J
It was subjected to the following test according to 15-R-5201. Here, the compressive strength test and splitting tensile strength test were conducted on a cylindrical specimen, the 1110 DE strength test was conducted on a prismatic specimen, and the specific gravity test was conducted on both.

As a result, fiber-reinforced concrete with performances (specific gravity, compressive strength, splitting tensile strength, and bending strength) as shown in FIGS. 3 to 6 was obtained. In the graphs of FIGS. 3 to 6, ◯ indicates specimens aged 1 week, and * indicates specimens aged 4 weeks.

As shown in Figure 3, in terms of specific gravity, it can be seen that the more carpet waste is added, the lower the specific gravity becomes.
In addition, in terms of bending strength, it was found that the bending strength of the 4-week old specimens increased as more carpet waste was added.

"Test Example 2" Carpet waste (carpet fiber) was added to normal Portland cement at 1wt%, 3wt%, Swt%,
7 wt% of each was added, dry kneaded, mixed with water while kneading with a mixer mixer, and then put into the popper of an extrusion molding machine and extruded with an extrusion screw, extrusion molding. Use a die to form a cylindrical shape with a diameter of 50 mm and extrude it, and use a cutter to cut it into a cylindrical shape.
A specimen was prepared by cutting it into a length of 0 mm. In addition, specimens were also produced using the same manufacturing method in the case where carpet waste was not added (0 wt %).

Then, these specimens were sequentially added to specimen A starting from 0 wt%.
(0wt%), specimen B (1wt%), specimen C (3w
t%), Specimen D (5wt%), Specimen E (7wt%)
%) and subjected to a static elasticity test.

FIG. 7 shows the relationship between stress and longitudinal strain obtained from the measurement results of this static elasticity test, and FIG. 8 shows the relationship between stress and transverse strain obtained from the measurement results of this static elasticity test.

From these results, it was found that the fiber-reinforced concrete molded product obtained by the present invention had increased toughness.

"Effects of the Invention" As explained above, the fiber-reinforced concrete molded product according to the present invention is produced by putting concrete into the hopper of an extrusion molding machine while it is still extrudable, and extruding it with an extrusion molding screw. A concrete molded product that is formed by extruding it into a predetermined shape with a die and cutting it in the length direction, and the 42 sides or edges of the woven carpet are aligned in the concrete of the molded product. This product is characterized by the fact that it is made by mixing carpet waste generated when cutting the pile part of the carpet with a cutter, so the carpet waste increases the strength of concrete instead of asbestos, and asbestos cement can be used at a low cost. It is possible to provide a fiber-reinforced concrete molded product that can replace.

[Brief explanation of the drawing]

Figures 1 and 2 show examples of the fiber-reinforced concrete molded product according to the present invention, with Figure 1 being a perspective view thereof, and Figure 2 showing an extrusion molding machine used to manufacture the molded product. Figures 3 to 6 are front views showing the structure of Test Example 1.
Figure 3 is a graph showing specific gravity, Figure 4 is a graph showing compressive strength, Figure 5 is a graph showing splitting tensile strength, Figure 6 is a graph showing bending strength, and Figure 6 is a graph showing bending strength. 7 and 8 show graphs obtained in Test Example 2, respectively. FIG. 7 is a graph showing the measurement results of vertical strain, and FIG. 8 is a graph showing the measurement results of lateral strain. 1... Concrete spacer 2... Extrusion molding machine

Claims (1)

[Claims] 1) Concrete is put into the hopper of an extrusion molding machine while it is extrudable, and while being extruded with an extrusion molding screw, it is extruded into a predetermined shape with an extrusion molding die, and the concrete is shaped into the specified length. This is a concrete molded product that is formed by cutting in the direction, and this occurs when the pile part of the carpet is cut with a cutter in order to align the top surface or edges of the woven carpet in the concrete of the molded product. A fiber-reinforced concrete molded product characterized by being mixed with carpet waste. 2) The fiber-reinforced concrete molded product according to claim 1, wherein the carpet waste is generated by shearing the pile portion using a shearing machine for a shearing machine.