JPH0811700B2 - Method for producing a hardened cemented plate having a dense surface and having gloss and light reflectivity - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention of the present application relates to a method for producing a plate-like cement hardened body using fiber-reinforced plastic (hereinafter referred to as FRP) as fine powder and using it as an aggregate.

[0002]

2. Description of the Related Art F reinforced with a reinforcing material such as glass fiber
Since RP has excellent properties, it is used in many fields, and its usage and production tend to increase more and more in the future. Since FRP has high strength and high durability, the difficulty of crushing and the difficulty of decomposing become problems when it is not used. Since large-sized molded products such as discarded ships, boats, and yachts, automobiles and consumer-use molded products, and trimming scraps and defective products generated in the manufacturing stage, FRP has excellent destructibility, At present, it is difficult to crush and disassemble, and it is difficult to dispose of it. In particular, large-scale fishery wastes such as fishing boats and boats are often left unattended, causing environmental damage and becoming a social problem. In view of such a current situation, it may be possible to reuse FRP waste as a resource from the viewpoints of environmental destruction and pollution prevention. However, in order to effectively use FRP waste as a resource, first, disconnection,
It is necessary to pulverize it into particles, powder or fine powder. However, even with the current advanced technology, it was extremely difficult to make FRP into a fine powder, but one of the inventors of the present invention, as a result of diligent efforts, has an average particle size of several μm.
We have succeeded in developing a device that can produce 100 kg of fine powder of about 100 m per hour. (Japanese Patent Application No. 3-126957)
The average particle size of FRP produced by this device is micro
Fine powder with a single-digit number in units (hereinafter referred to as FRP fine powder)
The U), when observed by a scanning electron microscope, in part 30μ
There were some relatively large powders of about m, but most of them were 4-5.
When the electron microscope was observed at a higher magnification of about 1 μm, a large number of particles of about 1 μm or less were observed. As for the glass fibers in the fine powder, most of them were fine powders, but some of them retained the morphology of the fibers. Observation of the cut surface of the glass fiber with a scanning electron microscope showed that it was instantaneously cut with a very sharp blade. A number of studies have been carried out by the present inventors on the recycling of fine powder FRP,
As one of them, a large amount of FRP fine powder can be used for civil engineering and construction, so I studied recycling of cement and concrete materials as aggregate. As a result, the present inventor examined the production of cement-based materials by replacing sand, lightweight sand, and a part of pumice, which are aggregates of those materials, with fine powder of FRP, and a secondary cement product, a concrete block, It has been found that FRP fine powder can be used as an aggregate for ALC and the like. (Japanese Patent Application No. 2-61080
issue)

[0003]

DISCLOSURE OF THE INVENTION The invention of the present application has succeeded in producing a cement-based material having a glossy smooth flat surface as a result of studying the use of FRP fine powder as an aggregate of the cement-based material. is there. Cement-based materials have long been used as materials for building structures because they have excellent mechanical properties. Further, when it is used as a building material, it is required to have beautiful appearance as well as mechanical strength. In addition, the surface of the building material needs to be colored and have a pattern such as unevenness. In order to deal with these points, polymer-based paint,
It is applied or sprayed, pasted with fired tiles, and pressed with a formwork having a pattern. The present inventor succeeded in this development as a result of researching whether or not those having mechanical properties and surface properties equivalent to or higher than these building materials can be produced by recycling FRP. In particular, a cement setting board having a surface texture comparable to that of fired tiles, that is, a cemented board cement has been developed.

[0004]

[Means for Solving the Problems] The surface of the present application is dense,
The method for producing a hardened cemented plate having gloss and light reflectivity is as follows.
Fine powder with an average particle size of P of one digit in micron units ,
The water is added with water containing an admixture mainly containing calcium chloride, and the mixture is kneaded and cured .

[0005]

According to the production process of the working of the present application has a plate-like hardened cement, 5 to 70% against cement weight cement FRP
Fine powder and admixture mainly consisting of calcium chloride were added
Since it is kneaded by adding water and cured , the surface is dense, has gloss and light reflectivity without any baking treatment.
It is possible to easily manufacture a plate-like cement hardened body having water repellency and widely used as a tile or the like.

[0006]

EXAMPLE An example of the invention of the present application will be described.
First, the FRP fine powder and white cement in the above-mentioned predetermined range with respect to the weight ratio of cement and white cement are mixed, and a predetermined amount of water is added thereto to make a cement paste, which is poured into a mold to be set. The formwork surface used should have a mirror-polished surface as much as possible. It is also an important factor to add various admixtures (inorganic or organic) for increasing the fluidity of the cement paste and adjusting the setting rate to the water to be added. As the admixture for that purpose, various admixtures (quick-setting agents, high-performance water reducing agents, etc.) are used. Although a smooth surface can be produced without using an admixture, the surface of the hardened cement product becomes more glossy by using the above-mentioned admixture. In order to further increase the density of the surface of the hardened cement product, it is also important to pour the cement paste into the mold and degas it with a vacuum pump. After pouring into the mold and demolding, cure in water. Depending on the case, the formwork is cured in the air. In order to form a particularly glossy and dense surface, it is desirable to keep it in the air at a low temperature of about 1 to 10 ° C. Curing period is 1
Days to 14 days, preferably 2 to 7 days. The surface of the hardened cement containing FRP fine powder produced by this method had a smooth and light-reflecting surface, and although it was vague, it was possible to take a picture of the surrounding environment like a mirror. Even if a character or a picture was drawn on this surface with oil-based ink, it could be easily wiped off. Further, even if water was dropped onto the surface of the hardened cement containing FRP fine powder, it did not soak into the surface, and remained as spherical water drops. The contact angle between the surface of the hardened cement and water at that time is 120 to 14
It was 0 °. It can be seen that, in the case of the conventional cement hardened body, compared to the fact that the dropped water droplets are instantly absorbed in the cement hardened body, it is extremely dense. When the surface condition of the FRP-containing cement hardened product having such a surface condition was observed with a scanning electron microscope, it was smooth and dense, and it was difficult to focus the microscope.
In the case of an ordinary cement hardened product, large crystals of about 20 to 30 μm were formed, but the FRP fine powder-containing cement hardened product produced according to the present invention showed a mode in which fine particles of sub-μm or less were aggregated. Further, an X-ray diffraction analysis of a hardened FRP-containing cement having a dense surface condition was performed, and it was the same in all cases regardless of the presence or absence of the admixture and the production conditions. The strength of the plate-shaped hardened cement containing FRP fine powder is (1) water-cement ratio, (2) F
It was greatly affected by the RP content. The water-cement ratio has a great effect on workability during production, and if it is small, the two cannot be mixed. When it is large, the strength of the hardened cement containing FRP fine powder is low. And the latter FRP fine powder content acts on both strength and workability. Therefore, the FRP fine powder content and the amount of water used will be determined depending on how much strength of the hardened cement is required. The mechanical strength of the hardened cement body cured in the air at a low temperature is lower than that when cured in water at room temperature. In order to improve that point, it is necessary to reinforce with carbon fiber, glass fiber, aramid fiber, vinylon fiber and other various fibers. Reinforcing with these fibers does not reduce the gloss and the denseness of the surface of the hardened cement containing FRP fine powder.
Moreover, the fracture morphology of the fiber-reinforced cement material was improved to have toughness rather than the brittle fracture that bursts from the maximum load generally found in cementitious materials. The control of the fracture mode is possible by the form of the fiber to be used (for example, chopped strand, milled fiber, felt, mat, strand, mesh, woven fabric, etc.) or the type and addition amount of the fiber. An example of a hardened cement containing FRP fine powder reinforced with a carbon fiber nonwoven fabric showed a bending strength of 19 MPa. Generally, there are various types of fired tiles depending on the purpose,
Bulk density is about 3 g / cm ³ , bending strength is 25-50MP
It is about a. Therefore, it is not so difficult to achieve the same or higher strength as the fired tile by increasing the fiber content such as carbon fiber and using the fiber such as mesh even in the hardened cement containing FRP fine powder. Not really. It is also possible to add a pigment to the cement paste to color the FRP fine powder-containing cement hardened product. Furthermore, since the apparent specific gravity of FRP fine powder is about 0.5, the manufactured plate-like cement hardened product can be made lightweight by increasing the content of FRP fine powder.

Next, the invention of the present application will be described in detail with reference to specific examples.

[First Embodiment] White Portland cement with a predetermined amount of F
RP fine powder was added, and both were thoroughly mixed. In this case, the amount of FRP added is 0.2 parts of the cement weight of 1.0 part,
It was 0.4 part, 0.6 part, 0.8 part, and 1.0 part.
A minimum amount of water that can be kneaded was added to this mixture, and the mixture was sufficiently stirred to prepare a cement paste. The amount of water used was 0.7 parts, 0.9 parts, 1.3 parts, 1.
5 parts and 1.7 parts. A predetermined amount of an inorganic calcium chloride-based admixture was added in advance to the added water. The water / admixture in this case was 15. Apply this cement paste to the formwork (3.6 cm x 6.6
(cm x 0.5 cm), and cured. After 1 day, it was demolded and cured in water for 2 weeks to prepare a hardened cement containing FRP fine powder. For comparison, F without addition of admixture
A cement hardened product containing RP fine powder was also prepared at the same time. The surface condition of the cement board can be visually evaluated for gloss and density,
It was evaluated by a permeation rate test by dropping water. For water penetration test, use a drop of water (0.05c
c) It was dropped, and the time until it soaked in everything was measured. When the water did not soak, it was evaluated as “none”. The results are shown in Table 1. The surface of the prepared hardened cement containing FRP fine powder became glossy by using the admixture. Also, as the amount of water used increases,
The surface density was reduced. The water permeation rate varied greatly depending on the presence or absence of the admixture. Water did not soak into the hardened cement mixture containing the admixture, but in the case of a normal cement-based material containing no admixture, it did so. Since the water permeation rate is related to the amount of pores present on the surface of the cured product, the FRP when an admixture is added
It can be seen that the surface of the hardened cement containing fine powder forms a more dense structure.

[0008]

[Table 1]

[0009]

Second Example FRP fine powder and a minimum amount of water that can be kneaded were added to white Portland cement, and both were thoroughly mixed to prepare a cement paste. The amount of FRP added and the amount of water used in this case are shown in Table 2. A predetermined amount of an inorganic calcium chloride-based admixture was added in advance to the added water. (Water / Admixture 15)
Form this cement paste into a mold (3.6 cm x 6.6 cm
× 0.5 cm), and after 1 day, it was demolded and cured in water for 2 weeks to prepare a cement-hardened board. For comparison,
A cement hardened board containing FRP fine powder without adding an admixture was also prepared at the same time. The bulk density, bending strength, Young's modulus, and specific strength of the produced FRP fine powder-containing cement hardened plate were measured, and the results are shown in Table 2. The bulk density and bending strength tended to decrease as the content of the FRP fine powder increased. This is because the amount of added water increased. Further, no difference was observed in mechanical properties even when the admixture was added. However, even when 20% of the cement weight was added with FRP fine powder, the bending strength thereof was 15 MPa. The specific strength (flexural strength / bulk density) in this case is FRP.
It was improved by 20% as compared with the case where no fine powder was added.

[0010]

[Table 2]

[0011]

[Third Example] In order to make the internal structure of the FRP fine powder-containing cement condensate more dense, it is necessary to vacuum deaerate the cement paste and remove the air bubbles in the paste. did. Add FRP fine powder and the minimum amount of water that can be mixed to white Portland cement,
Both were thoroughly mixed to make a cement paste. In this case, the amount of FRP added and the amount of water used were 0.05 parts and 0.4 parts by weight of the cement. A predetermined amount of an inorganic calcium chloride-based admixture was added in advance to the added water. The water / admixture ratio in this case is 1
It was 5. Form this cement paste into a mold (3.6 cm
(× 6.6 cm × 0.5 cm), the mixture was placed in a vacuum desiccator, and the cement paste was sucked for 5 minutes by a vacuum pump to deaerate and harden the cement paste. I removed the mold one day later,
It was cured in water for 2 weeks to prepare a hardened cement. For comparison, an FRP fine powder-containing cement hardened product containing no admixture was also prepared at the same time. Table 3 shows the bulk density and mechanical properties of the prepared hardened cement containing FRP fine powder. Even when the vacuum deaeration treatment was performed, no significant difference was observed in the bulk density and bending strength of the FRP fine powder-containing cement hardened product, but the surface glossiness, compactness, and light reflectivity were further improved. Further, the surface hardness was improved in the cured product to which the FRP fine powder was added. However, since the light reflectivity was slightly lacking as compared with the fired tile, the experiment shown in the following fourth example was conducted in order to make it more dense.

[0012]

[Table 3]

[0013]

[Fourth Embodiment] 0.1 and 0.2 of FRP / cement,
Water / cement (W / C) 0.4, water / admixture ratio 10
As a cement paste, the mixture was thoroughly stirred and then poured into a mold. These cement hardened bodies are treated in water (15
C., 50.degree. C.) or air (5.degree. C., 15.degree. C.) for curing to prepare a hardened cement. The surface condition of the hardened cement containing FRP fine powder produced was 5 in the air-cured one than in the water-cured one, regardless of the content of the FRP fine powder. The ones that were aged in a refrigerator at ℃ showed a denser surface condition. When observing the surface condition of the hardened cement product with a scanning electron microscope, no large crystals were found that were smooth and dense, and no admixture was added. there were. When X-ray diffraction analysis was performed on these cement hardened products, they were the same in all cases regardless of the presence or absence of the admixture and the production conditions. However, the FRP fine powder-containing cement hardened product having the tile-like surface image produced under the above conditions has a low bending strength of 8 MPa because it is cured in air at a low temperature. Therefore, in order to improve this point, It was reinforced with various fibers.

[0014]

[Fifth Embodiment] A cement paste was prepared with FRP / cement at 0.1, water / cement (W / C) at 0.4, and water / admixture ratio of 10. Six carbon fiber non-woven fabrics (thickness 0.3 mm, basis weight 33 g / m ² , PAN system) were put in this, and after sufficiently impregnating, a form (3.6 cm × 6.
6 cm × 0.5 cm). After being placed in a vacuum desiccator and deaerated, these FRP fine powder-containing cement hardened bodies were cured in a refrigerator air (5 ° C.). For comparison, a hardened cement containing FRP fine powder containing no carbon fiber was also prepared under the same conditions. The bulk density and mechanical properties of the prepared hardened cement of FRP fine powder containing cement are shown in Table 4. The carbon fiber content in the hardened cement of FRP fine powder containing cement was about 2%. Even if carbon fiber nonwoven fabric is added,
The surface condition of the hardened cement containing FRP fine powder does not change, and the denseness, luster, and equivalent to that of fired tiles.
It showed light reflectivity and no water absorption. The reinforcing strength of the FRP fine powder-containing cement hardened body became 19 MPa by reinforcing with the carbon fiber, which was 2.4 times that of the additive-free bending strength. Further, the fracture mode of the hardened cement containing FRP fine powder was remarkably different depending on the arrangement of the carbon fibers.
When the carbon fiber non-woven fabric was not added, the brittle fracture was typical.
The cement hardened product containing RP fine powder showed high toughness without being divided into two parts.

[0015]

[Table 4]

[0016]

INDUSTRIAL APPLICABILITY As described above, the present application reuses FRP waste as a resource, has a dense surface, and has a surface texture similar to that of a so-called fired tile, which is a hardened plate cement having gloss and light reflectivity. It is a new material developed with.
The cement hardened product having a glossy flat surface made by the present invention has a surface having a high hardness, a dense, and pore-free water-repellent property. For those with such a surface, penetration of water into the interior of the hardened cement is avoided, which frequently occurs in extremely cold regions. The penetrated water freezes and it expands and destroys the cement structure. Helps prevent freeze-thaw phenomenon.
In addition, many social problems due to acid rain have begun to occur.One of the problems is that acid rainwater that has infiltrated inside the cement structure erodes the hardened cement and reduces the strength of the structure. is there. However, according to the present invention, since it is difficult for water to permeate and the FRP fine powder that is an aggregate has a high chemical resistance, it is stronger against acid rain than conventional cement-based building materials. . Further, since the apparent specific gravity of the FRP fine powder is about 0.5, it is possible to provide a lightweight cement-based building material by increasing the content of the FRP fine powder. On the other hand, tile, which is a building material that is strong against freeze-thaw and acid rain, is made by kneading clay and other additives, applying glaze to the surface, and applying it at a high temperature of 1300 ° C for 30 to 70 hours. It is a product in which a glass layer is formed by firing. Therefore, the energy cost required for it is enormous, and the cost is inevitably high. On the other hand, the FRP fine powder-containing cement hardened material of the present invention aiming at the recycling of FRP has a surface property of the cement-based material that is hard, dense and glossy, capable of reflecting light, and is not fired. Since energy is not required during manufacturing, it contributes to energy saving and can be manufactured at extremely low cost.

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area C04B 22:12)

Claims (1)

[Claims] 1. The weight ratio of cement to cement is 5 to 7.
The average particle size of 0% fiber reinforced plastic is in microns
And fine powders of single digit in and kneaded with water added with the main and the mixed <br/> dispersible calcium chloride, dense surface, characterized in that curing, gloss and light reflection For producing a hardened cemented plate-like cement