JP2764684B2 - Concrete member and method for manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concrete (mortar) member, and more particularly to a concrete member having high bending strength and excellent durability such as watertightness, chemical resistance, and salt damage resistance.

[0002]

2. Description of the Related Art Conventionally, concrete members are mainly made of steel, wooden,
It is manufactured by casting concrete in a form such as FRP. In addition, a concrete precast plate may be used as a buried formwork. In this case, there is an advantage that the step of removing the mold is not required, and if the buried mold is made of highly durable concrete, the durability of the entire concrete member is improved. On the other hand, concrete members are usually made using reinforcing steel as a reinforcing material.

[0003]

However, iron,
Concrete cast into wooden, FRP or other formwork
This is a commonly used concrete with poor abrasion resistance and water tightness.In addition, if the concrete has defects such as fine cracks or junkers due to improper construction or curing, chloride etc. will permeate and the internal reinforcing steel will rust. In addition, there is a problem that the durability of the concrete member is reduced. Although the performance of the concrete itself can be enhanced by adding an admixture such as fiber or silica fume, it is economically unfavorable to increase the performance of the entire member because it increases the cost.

[0004] When a concrete precast plate is used as a buried form, if the concrete has a high durability, the buried form protects the concrete inside, so that the durability of the entire member is improved. However, this does not improve the bending strength of the concrete member. In addition, such a concrete buried mold has a problem that the member is thick, as a result, the weight is increased, and labor is required for assembling the form. Furthermore,
Recently, light and thin concrete members have been desired.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a concrete member having high bending strength and excellent durability such as water tightness, chemical resistance and salt damage resistance. The gist is that, based on 100 parts by weight of hydraulic cement, 5 to 100 parts by weight of a formaldehyde-based resin precursor which does not substantially contain water but generates water by a curing reaction, and if necessary, additives and / or A hardened cementitious material containing a cementitious material molded from a composition containing a filler and cured by using water generated by a curing reaction of the resin precursor by heating at 100 to 300 ° C. is applied to the surface layer of concrete. And / or a concrete member having a configuration provided inside.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In the following, the present invention will be described in detail. In the concrete member according to the present invention, the reinforced hardened body provided on the surface layer and / or inside thereof contains hydraulic cement and substantially water. However, it is molded with a composition containing a formaldehyde-based resin precursor that generates water by a curing reaction, and an additive and / or a filler as required.

[0007] Conventional cement can be used as the hydraulic cement. Examples include Portland cement (eg, ordinary Portland cement, early-strength Portland cement, moderately heated Portland cement, etc.),
Mixed cement (eg blast furnace cement, silica cement,
Fly ash cement, etc.), special cements (eg, alumina cement, oil well cement, etc.), various plasters, and the like. This hydraulic cement can be used alone, or two or more of the above cements can be used in combination.

As the formaldehyde resin precursor, for example, a phenol resin precursor, a melamine resin precursor or a urea resin precursor is used. Although these resin precursors do not substantially contain water, they are hardened while generating water by being subjected to a heat treatment, and hydration of the hydraulic cement is performed by water generated as a result of a curing reaction. A reaction takes place to obtain a cementitious reinforced hardened body.

If the resin precursor is alcohol-soluble, it can be used by dissolving the resin precursor in alcohol beforehand in order to facilitate mixing with each component and improve moldability. . As the alcohols, a wide range of alcohols such as methanol, ethanol, propanol, butanol, cyclohexanol, phenol, cresol, ethylene glycol and trimethylene glycol can be used.

The mixing ratio of the formaldehyde-based resin precursor is determined according to the moldability and performance, but is generally in the range of 5 to 100 parts by weight of the formaldehyde-based resin precursor per 100 parts by weight of the hydraulic cement. (Excluding alcohol) is good. When the amount of the resin precursor is less than 5 parts by weight, the mixed state of the respective materials is poor, and the cured reinforced body is likely to have a defect. Conversely, when the amount is more than 100 parts by weight, the molded product is cracked and the strength tends to level off or tends to decrease, which is not economically preferable.

In the above-mentioned hardened cured product of the present invention, a polymer having an acid amide bond, for example, polyamide or polyacrylamide is preferably used as an additive for modifying the performance of the molded article. These additives are more effective if they are pulverized before mixing. The compounding ratio of this additive is generally 0.5 to 30 parts by weight, preferably 2 to 20 parts by weight, based on 100 parts by weight of the formaldehyde resin precursor. If the amount is less than 0.5 part by weight, the effect is not obtained, and if the amount exceeds 30 parts by weight, the reforming effect is not increased and it is uneconomical.

In addition to the above additives, known hardeners, silane coupling agents, coloring agents, and the like can be used in the reinforced cured product of the present invention. For example, as a lubricant
Glycerol, glycerol triacetate, phthalic anhydride, furfural, alkylphenol, zinc stearate, magnesium stearate, rosin, and the like, as silane coupling agents, γ-aminopropyl triethoxysilane, γ-ureidopropyl triethoxysilane, There are γ-glycidoxypropyltrimethoxysilane and the like, and as the coloring agent, there are organic and inorganic pigments such as aniline black, carbon black and titanium oxide.

As the above-mentioned filler, a commonly used filler such as wood flour, pulp, cotton floc, stone flour, heavy calcium carbonate, aluminum hydroxide, sand, lightweight aggregate, glass fiber, carbon fiber and the like is used. be able to. When these fillers are used, it is preferable to increase the mixing ratio of the resin precursor according to the amount of the filler used.

These formaldehyde-based resin precursor and hydraulic cement, and additives and fillers added as required, are mixed with a mortar mixer, a blender, a kneader,
Each component is mixed into a powder, paste, or dough using a crimp mixer, a hot roll, or the like. The mixed material is dried, pulverized, and classified to form a molding material, and molded into a required shape using the molding material. As a molding method, means such as compression molding, extrusion molding, and injection molding can be used.

Further, the molded product is subjected to a heat treatment. By this, when the resin precursor is cured, a hydration reaction of the cement is caused by water generated as a result of the curing reaction, and a cementitious reinforced cured body exhibiting high strength and excellent water resistance and heat resistance is produced. obtain. The heating temperature during the heat treatment is generally in the range of 100 to 300 ° C., preferably 15 ° C.
The range of 0 to 250 ° C is good.

Next, a method of manufacturing a concrete member according to the present invention will be described. In order to provide the reinforced hardened body obtained as described above in the surface layer and / or inside of concrete, a conventional mold is used. There are a method of pouring concrete by installing a reinforced hardened body therein, a method of bonding the reinforced hardened body to concrete later, and a method of using the reinforced hardened body as a buried form.

FIG. 1 is a perspective view of an embodiment in which a reinforced hardened body is provided on the surface layer of concrete, and its manufacturing method includes the methods shown in FIGS. That is, as shown in FIG. 2, a concrete member is formed by placing a reinforced hardened body 1 in a mold 3 and casting concrete 2 therein.
As shown in FIG. 3, a reinforced hardened body 1 is attached to concrete 2 using an adhesive 4 to form a concrete member, and as shown in FIG. This is a method in which the hardened body 1 is erected as an embedded formwork, fixed with a support member 5 so as not to fall down due to the lateral pressure of the concrete, and then concrete 2 is cast to form a concrete member. FIG. 5 shows a manufacturing method in which the reinforced hardened body is provided inside the concrete, in which the hardened hardened body 1 is fixed at a predetermined position inside the formwork 3 with a spacer or the like, and the concrete 2 is fixed. The concrete member is formed by casting.

In the present invention, the reinforced hardened body can be cast by casting concrete without particularly treating the surface.
Although a concrete member integrated with the reinforced hardened body can be obtained, more preferably, the surface of the reinforced hardened body in contact with the concrete is made uneven, or an epoxy resin,
It is preferable to apply an adhesive such as an unsaturated polyester resin, a latex such as a styrene-butadiene copolymer, an acrylonitrile-butadiene copolymer, or an ethylene-vinyl acetate copolymer, or an emulsion before casting concrete.

The concrete to be poured is one usually used in the civil engineering and construction fields, for example, ordinary concrete,
It is lightweight concrete, high-strength concrete, resin concrete, or a mortar thereof, and is not particularly limited. It should be noted that the concrete member according to the present invention does not exclude reinforcement by a reinforcing bar, and a concrete member can be made by combining with a commonly used reinforcing bar.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below. The concrete member according to the present invention has high bending strength, water tightness,
It is clarified below that it has excellent durability such as chemical resistance and salt damage resistance.

Example 1 100 parts by weight of alumina cement (manufactured by Denki Kagaku Kogyo Co., Ltd., trade name: Denka Alumina Cement 1), an alcohol solution of a phenol resin precursor (manufactured by Showa Polymer Co., Ltd.)
Trade name Shaunor BRS-330, nonvolatile content 60.6
%) 21.6 parts by weight, 1.4 parts by weight of N-methoxymethylated polyamide (trade name: Toresin, manufactured by Teikoku Chemical Sangyo Co., Ltd.) in which hydrogen of an amide bond is substituted by 30% by a methoxymethyl group, and 2.3 of glycerol After pre-mixing the parts by weight with a mortar mixer for 2 minutes, a pair of roll rotation ratios was set to 1:
The mixture was mixed for 4 minutes with a rubber roll set at 1.3. After the dough-like mixture wound around the rolls in this mixing was peeled off, the mixture was passed several times between rolls having a rotation ratio set to 1: 1 and roll-formed into a sheet having a thickness of 2 mm.
Heat-treated at 00 ° C for 18 hours to form a sheet-shaped reinforced cured product 1
Was manufactured.

Then, as shown in FIG. 2, the steel mold 3 having a thickness of 40.times.40.times.160 mm in length has a thickness of 2.times.
Installing the reinforced cured body 1 having a width of 40 x a length of 160 mm,
The ordinary concrete shown in Table 1 was cast. 24 from casting
After a lapse of time, steam curing was performed at 65 ° C. for 4 hours to produce a concrete member integrated with the reinforced hardened body 1. Age 7
A day later, a bending test was performed according to JIS R5201. As a result, the bending strength is 17.7 N / mm ² ,
The bending strength of the member made of only ordinary concrete manufactured under the same conditions was 1.9 times the bending strength of 9.50 N / mm ² .

[0023]

[Table 1]

Example 2 An ordinary concrete having the composition shown in Table 1 was prepared in a size of 40 × 40 × 1.
It was molded to a size of 60 mm, cured by steam curing at 65 ° C. for 4 hours. After 7 days of age, as shown in FIG.
Using the epoxy adhesive 4, the reinforced hardened body 1 obtained in the same manner as in Example 1 was attached to the bottom of the ordinary concrete 2 to produce a concrete member. After curing the adhesive, J
A bending test was performed according to IS R5201. As a result, the bending strength was 16.4 N / mm ² , and the bending strength of the member made of only ordinary concrete manufactured under the same conditions was 9.5.
It was 1.7 times of 0 N / mm ² .

Example 3 As shown in FIG. 4, in order to use a reinforced cured product obtained in the same manner as in Example 1 as an embedded mold, a thickness 2 × width 4
Two reinforced hardened bodies 1 having a length of 0 × 160 mm were erected on a steel plate 3 and supported by a support member 5 so as not to fall down, and the ends were separated by plywood. The ordinary mortar shown in Table 1 was poured into this, and 24
After a period of time, steam curing is performed at 65 ° C. for 4 hours, and a concrete member (thickness 15 × width 40 ×
(Length 160 mm). After 7 days of material age, JIS
A bending test was performed according to R5201. As a result, the bending strength was 45.4 N / mm ² , and the bending strength of the member made of only ordinary mortar manufactured under the same conditions was 13.6 N / mm ^2.
3.3 times that of ² .

Example 4 A test was performed in the same manner as in Example 2 except that the mortar to be cast was a lightweight mortar shown in Table 1 above. as a result,
The flexural strength is 17.8 N / mm ² , and the flexural strength of only the lightweight mortar produced under the same conditions is 3.6 N / mm.
It was 4.9 times of ² . The member at this time has a specific gravity of 1.
It was lightweight at 69.

Example 5 As shown in FIG. 5, a material molded in the same manner as in Example 1 was subjected to heat treatment after forming a circular hole (pitch: 20 mm) having a diameter of 10 mm before heat treatment. , Thickness 2 x width 20
A reinforced cured product 1 of 0 × 200 mm in length was produced. Attach a spacer (not shown) to this, thickness 15 × width 200
× Set in a steel mold 3 having a length of 200 mm. A normal mortar shown in Table 1 was poured into this, and after 24 hours at 65 ° C.
For 4 hours to produce a concrete member integrated with the reinforced hardened body. After 7 days of age, width 40 ×
It was cut to a length of 200 mm and subjected to a bending test according to JIS R5201. As a result, the bending strength was 19.7 N.
/ Mm ^2, which is 1.5 times the bending strength of 13.6 N / mm ² of the member made of only mortar manufactured under the same conditions.

Example 6 A concrete member having a thickness of 40.times.40.times.160 mm in length and obtained by the same operation as in Example 1 was dried at 80.degree. It was coated with a resin and immersed in water for one month to determine the water absorption. After that, it was immersed in a 5% hydrochloric acid aqueous solution for 14 days, and the state of erosion on the surface was observed. Similarly, a test was also performed on a concrete-only member without a reinforced hardened body, and the measured values were compared. As a result, the water absorption was 0.5%, and no erosion of the surface was observed even when immersed in 5% hydrochloric acid. On the other hand, a member made of only concrete produced under the same conditions had a water absorption of 3.4%. After immersion in 5% hydrochloric acid, the paste was eroded, and the surface became rough.

[0029]

Since the present invention has the above configuration,
Bending strength is high, so cross-sectional area can be reduced and weight can be reduced, while watertightness, chemical resistance,
There are various effects that a concrete member having excellent durability such as salt damage resistance can be obtained. In addition, applications include construction-related fields such as foundations, columns, beams, flooring materials, exterior wall materials, and interior materials, civil engineering-related fields such as waterways, bridges, road paving slabs, tunnels, tanks, pillows, and machine tool pedestals.
It can be widely applied to machine-related fields such as press dies and platens, and has the effect of expanding the field of use.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of a concrete member according to the present invention.

FIG. 2 is a schematic sectional view showing a method for manufacturing a concrete member according to the present invention.

FIG. 3 is a schematic sectional view showing another embodiment of the concrete member according to the present invention.

FIG. 4 is a schematic sectional view showing another method for manufacturing a concrete member according to the present invention.

FIG. 5 is a schematic sectional view showing still another method for manufacturing a concrete member according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reinforced hardened body 2 Concrete 3 Formwork 4 Adhesive 5 Supporting material

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // E04B 1/16 E04B 1/16 A (56) References JP-A-2-282550 (JP, A) JP-A-4- 231533 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) E04C 3/20 C04B 24/30 E04C 2/04 E04C 3/34

Claims (4)

(57) [Claims] 1 to 100 parts by weight of hydraulic cement, 5 to 100 parts by weight of a formaldehyde-based resin precursor which does not substantially contain water but generates water by a curing reaction, and if necessary, additives and / or A hardened cementitious material containing a cementitious material molded from a composition containing a filler and cured by using water generated by a curing reaction of the resin precursor by heating at 100 to 300 ° C. is applied to the surface layer of concrete. And / or a concrete member characterized by being provided inside. 2. 100 parts by weight of hydraulic cement, 5 to 100 parts by weight of a formaldehyde resin precursor which does not substantially contain water but generates water by a curing reaction, and if necessary, additives and / or A reinforced hardened body containing cementum, which is molded from a composition containing a filler and is hardened by utilizing water generated by a hardening reaction of the resin precursor by heating at 100 to 300 ° C. And then casting concrete into the formwork to integrate with the reinforced hardened body. 3. The method for manufacturing a concrete member according to claim 2, wherein the reinforced hardened body is assembled as a formwork, and concrete is poured into the formwork to be integrated with the reinforced hardened body. 4. A method of manufacturing a concrete member, comprising bonding the reinforced hardened product according to claim 2 to hardened concrete with an adhesive to integrate the reinforced hardened product with the hardened concrete.