JPH0718783A - Concrete member and its production - Google Patents

Abstract

PURPOSE:To increase durability, by fitting a reinforced cured material obtained from hydraulic setting cement and formaldehyde resin precursor or the like onto the surface of concrete and/or in the inside thereof CONSTITUTION:Formaldehyde resin precursor 5-100 pts.wt. of pheixol resin precursor or the like is mixed with hydraulic setting cemen 100 pts.wt. of Portland cement or the like. Polymer having acid-amide bonds like polyamide or the like and/or lubricant, silane coupling agent, and additives like colorant are mixed with the cement and the precursor, when necessary. And after the mixture has been molded to form a specified shape, it is heated to form a reinforced cured material 1. Moreover, the cured material has been put in a mold, concrete 2 is placed to form a concrete member.

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, particularly 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, wood, or both on-site construction and factory products.
It is manufactured by placing concrete on a mold made of FRP or the like. In addition, a concrete precast plate may be used as an embedded formwork. In this case, there is an advantage that the step of removing the formwork is unnecessary and that the durability of the entire concrete member is improved if the buried formwork is made of concrete having high durability. On the other hand, concrete members are usually made of reinforcing steel.

[0003]

However, the concrete to be placed in a mold made of steel, wood, FRP, etc. is a commonly used concrete and is inferior in wear resistance and watertightness. If the concrete has defects such as fine cracks or junkers due to inadequate construction or curing, chlorides and the like penetrate and the internal reinforcing bars rust, which lowers the durability of the concrete members. Although it is possible to improve the performance of the concrete itself by adding an admixture such as fiber or silica fume, it is not economically preferable to improve the performance of the entire member, however, because the cost is high.

When a concrete precast plate is used as an embedded formwork, if the concrete having a high durability is used, the embedded formwork protects the concrete inside, so that the durability of the entire member is improved. However, it does not improve the bending strength of the concrete member. Further, such an embedded mold made of concrete has a problem in that the member is thick and, as a result, the weight is large and it takes a lot of effort to assemble the mold. Furthermore, recently, concrete members have been desired to be light and thin.

[0005]

Therefore, according to the present invention,
It is intended to provide a concrete member having high bending strength and excellent durability such as watertightness, chemical resistance, and salt damage resistance, and the gist thereof is to include hydraulic cement and substantially water. Formaldehyde resin precursor that produces water upon curing, and if necessary additives and / or
Alternatively, a reinforced cured body obtained from a composition containing a filler,
It is a concrete member characterized in that it is provided in a surface layer portion and / or inside of concrete, such as a concrete reinforcing material and a buried formwork.

The present invention will be described in detail below. First, the reinforced hardened body provided on the surface layer portion and / or inside of the concrete according to the present invention will be described. As the hydraulic cement to be used, conventional cement can be used. Examples thereof include Portland cement (eg, ordinary Portland cement, early-strength Portland cement, moderate heat Portland cement, etc.), mixed cement (eg, blast furnace cement, silica cement, fly ash cement, etc.),
Special cement (eg, alumina cement, oil well cement, etc.), various plasters, etc. Hydraulic cement is 1
Although it can be used as a seed, it is also possible to use a mixture of two or more of the above cements.

The formaldehyde resin precursor used is a phenol resin precursor, a melamine resin precursor,
A urea resin precursor or the like, which is substantially free of water, is used. If the precursor is alcohol-soluble, the precursor may be dissolved in alcohol in advance and used in order to facilitate mixing of the components. As the alcohol in the present invention, a wide range of alcohols such as methanol, ethanol, propanol, butanol, cyclohexanol, phenol, cresol, ethylene glycol and trimethylene glycol can be used.

The blending ratio of the formaldehyde resin precursor according to the present invention may be determined according to moldability and performance,
Generally, the range of 5 to 100 parts by weight of the formaldehyde resin precursor (100 parts by weight of the hydraulic cement) is preferable. When the amount of the precursor is less than 5 parts by weight, the mixed state of each material is poor and defects are likely to occur in the reinforced cured body. On the other hand, if the amount is more than 100 parts by weight, the molded product is cracked and the strength tends to reach a peak or lower, which is not economically preferable.

In the reinforced cured product according to the present invention, a polymer having an acid amide bond, such as polyamide or polyacrylamide, is preferably used as an additive for modifying the performance of the molded product. These additives are more effective if they are pulverized in advance before mixing. The mixing ratio is generally 0.5 to 30 parts by weight, and further 2 to 20 parts by weight with respect to 100 parts by weight of the formaldehyde resin precursor.
Parts by weight are preferred. If it is less than 0.5 part by weight, the effect is not obtained, and if it exceeds 30 parts by weight, the modifying effect is not great and it is uneconomical.

In addition to the above-mentioned additives, known lubricants, silane coupling agents, colorants and the like can be used in the reinforced cured product according to the present invention. For example, as a lubricant, glycerol, glycerol triacetate, phthalic anhydride, furfural, alkylphenol, zinc stearate,
Examples of silane coupling agents such as magnesium stearate and rosin include γ-aminopropyl triethoxysilane, γ-ureidopropyltriethoxysilane, γ-
Glycidoxypropyltrimethoxysilane and the like.
Colorants include organic and inorganic pigments such as aniline black, carbon black and titanium oxide.

As the filler according to the present invention, wood powder, pulp, cotton flocs, stone powder, ground calcium carbonate,
Conventional materials such as aluminum hydroxide, sand, lightweight aggregate, glass fiber and carbon fiber can be used. When these fillers are used, it is preferable to increase the mixing ratio of the precursor according to the amount used.

The composition containing these formaldehyde-based resin precursor, hydraulic cement, and if necessary additives and fillers is prepared by using a mortar mixer, a blender, a kneader, a Banbury mixer, a hot roll and the like. Are mixed in the form of powder, paste or dough. Then, it is formed into a desired shape and heat-treated to cure it. It is also possible to dry, crush, and classify the mixed material to prepare a molding material, and then to perform compression molding, extrusion molding, injection molding and curing. The heating temperature is generally 1
The range of 00 to 300 ° C., preferably 150 to 250 ° C. is good.

Next, a method for manufacturing the concrete member according to the present invention will be described. In order to provide the reinforced hardened body obtained as described above on the surface layer part and / or inside of concrete, a method of pouring concrete by installing the reinforced hardened body molded inside a conventional formwork, the reinforced hardened body And a method of using the reinforced hardened body as an embedded formwork.

FIG. 1 is a perspective view showing an embodiment of a concrete member according to the present invention. 2 to 5 show a method of providing the reinforced hardened body on the surface layer portion and / or the inside of the concrete, and FIG. 2 shows the reinforced hardened body 1 on the mold 3.
Is installed and concrete 2 is cast to form a concrete member, FIG. 3 is a concrete member that is formed by adhering the reinforced hardened body 1 to the concrete 2 using the adhesive 4, and FIG. 4 is a flat plate shape. The reinforced hardened body 1 is erected as an embedded formwork on the formwork 3, and is fixed with a support material 5 so as not to fall by the lateral pressure of concrete, and then the concrete 2 is cast to form a concrete member. Is to fix the reinforced and hardened body 1 inside the mold 3 at a predetermined position with a spacer or the like, and cast concrete 2 to form a concrete member.

In the case of the reinforced hardened material according to the present invention, a concrete member integrated with the reinforced hardened material can be obtained by pouring concrete without treating the surface of the reinforced hardened material. Making the surface of the cured body uneven, epoxy resin, adhesive such as unsaturated polyester resin on the surface, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer,
A latex or emulsion such as an ethylene-vinyl acetate copolymer is preferably applied before placing concrete.

[0016] The concrete to be poured is one commonly used in the field of civil engineering and construction, for example, ordinary concrete, lightweight concrete, high-strength concrete, resin concrete, or mortar thereof, and there is no particular limitation.

The concrete member according to the present invention does not exclude reinforcement by a reinforcing bar, but can be made by combining it with a commonly used reinforcing bar.

[0018]

EXAMPLES Examples of the present invention will be described below to clarify that the concrete member of the present invention has high bending strength and excellent durability such as watertightness, chemical resistance and salt damage resistance.

[Example 1] Alumina cement (Denka Alumina Cement No. 1 manufactured by Denki Kagaku Kogyo Co., Ltd.) 1
00 parts by weight, alcohol solution of phenol resin precursor (Showa Highpolymer Co., Ltd., trade name Shonor BRS-3
30, non-volatile content 60.6%) 21.6 parts by weight, N-methoxymethylated polyamide (trade name: resin resin, Teikoku Chemical Industry Co., Ltd.) in which hydrogen of amide bond is replaced by 30% by methoxymethyl group 1.4 2 parts by weight of glycerol and 2.3 parts by weight of glycerol were premixed for 2 minutes with a mortar mixer, and then mixed for 4 minutes with a rubber roll machine in which the rotation ratio of a pair of rolls was set to 1: 1.3. After peeling off the dough-shaped mixture wound on the rolls by this mixing, the mixture was passed several times between rolls set to a rotation ratio of 1: 1 to roll-form a sheet having a thickness of 2 mm, and then at 200 ° C. A heat treatment for 18 hours was performed to produce a sheet-like reinforced cured body.

As shown in FIG. 2, a reinforced and hardened body of thickness 2 × width 40 × length 160 mm was installed on the bottom plate of a steel mold having a thickness of 40 × width 40 × length 160 mm. The ordinary concrete shown is placed. Twenty-four hours after casting, steam curing was performed at 65 ° C. for four hours to produce a concrete member integrated with the reinforced hardened body. 7 days later, JISR
A bending test was performed according to 5201. As a result, the flexural strength was 17.7 N / mm ² , and the flexural strength of the member made of normal concrete under the same conditions was 9.50 N / mm ^2.
It was 1.9 times that of ² .

[0021]

[Table 1]

Example 2 Regular concrete having the composition shown in Table 1 was molded into a size of 40 × 40 × 160 mm at 65 ° C.
It was cured by steam curing for 4 hours. After 7 days of age, as shown in FIG. 3, a reinforced hardened body obtained in the same manner as in Example 1 was attached to the bottom of the ordinary concrete using an epoxy adhesive to prepare a concrete member.
After the adhesive was cured, a bending test was performed according to JIS R5201. As a result, the bending strength is 16.4 N / mm ^2.
The bending strength was 9.50 N / mm ² , which was 1.7 times the bending strength of the member made of only ordinary concrete under the same conditions.

[Embodiment 3] As shown in FIG.
In order to use the reinforced hardened body obtained in the same manner as the above as an embedded formwork, two reinforced hardened bodies having a thickness of 2 x a width of 40 x a length of 160 mm are erected on a steel plate and supported by a supporting material so as not to fall It was supported and the ends were separated by plywood. To this, ordinary mortar shown in Table 1 was placed, and after 24 hours, steam curing was performed at 65 ° C. for 4 hours to make it a concrete member (thickness 15 × width 40 × length 160 mm) integrated with the reinforced hardened body. Was produced. After 7 days of age, a bending test was performed according to JIS R5201. As a result, the flexural strength was 45.4 N / mm ² , which was 3.3 times the flexural strength 13.6 N / mm ² of the member made of only ordinary mortar under the same conditions.

[Example 4] A test was conducted in the same manner as in Example 2, except that the mortar to be cast was a lightweight mortar shown in Table 1. As a result, the bending strength was 17.8 N / mm ² , which was 4.9 times the bending strength of 3.6 N / mm ² of the lightweight mortar-only member manufactured under the same conditions. The member at this time was lightweight with a specific gravity of 1.69.

[Embodiment 5] As shown in FIG.
10m diameter before heat treatment
A circular hole of m (pitch 20 mm) was opened, and then heat treatment was carried out to manufacture a reinforced cured body having a thickness of 2 × a width of 200 × a length of 200 mm. A spacer was attached to this, and it was set in a steel mold frame having a thickness of 15 mm, a width of 200 mm and a length of 200 mm. After placing ordinary mortar shown in Table 1 on this, 6 hours later,
Steam curing was carried out at 5 ° C. for 4 hours to prepare a concrete member integrated with the reinforced hardened body. 7 days old, width 4
It cut | disconnected to 0x length 200mm, and performed the bending test according to JISR5201. As a result, the bending strength was 19.
A 7N / mm ^2, was 1.5 times the flexural strength 13.6N / mm ² of the mortar just member manufactured in the same conditions.

Example 6 A concrete member having a thickness of 40 mm, a width of 40 mm and a length of 160 mm obtained in the same manner as in Example 1 was dried at 80 ° C., and then the surface other than the reinforced hardened body was cured with epoxy. The resin was coated and immersed in water for 1 month to determine the water absorption. After that, it was dipped in a 5% hydrochloric acid aqueous solution for 14 days, and the erosion state of the surface was observed. Similarly, a member made only of concrete without a reinforced hardened body was tested and the measured values were compared. As a result, the water absorption rate was 0.5%, and no surface erosion was observed even when immersed in 5% hydrochloric acid. On the other hand, the water absorption of the concrete-only member manufactured under the same conditions was 3.4%, and the paste was eroded and the surface became rough after being immersed in 5% hydrochloric acid.

[0027]

INDUSTRIAL APPLICABILITY As described above, the concrete member of the present invention has a high bending strength, and therefore has an effect of reducing the member cross section and reducing the weight, and further, has a watertightness, a chemical resistance, a salt damage resistance and the like. It can be seen that it has excellent durability. Applications include foundations, columns, beams, flooring materials, outer wall materials, interior materials, and other construction-related fields, waterways, bridges, road paving plates, tunnels, tanks,
It can be widely applied to civil engineering related fields such as sleepers, and machine related fields such as machine tool pedestals, press dies and surface plates.

[Brief description of drawings]

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

FIG. 2 is a schematic sectional view showing an embodiment of the concrete member according to the present invention.

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

FIG. 4 is a schematic sectional view showing an embodiment of the concrete member according to the present invention.

FIG. 5 is a schematic sectional view showing an embodiment of the concrete member according to the present invention.

[Explanation of symbols]

 1 Reinforced hardened body 2 Concrete 3 Formwork 4 Adhesive 5 Support material

Claims (4)

[Claims] 1. Obtained from a composition containing a hydraulic cement and a formaldehyde resin precursor which is substantially free of water but produces water by a curing reaction, and optionally an additive and / or a filler. A concrete member configured by providing a reinforced hardened body on the surface layer part and / or inside of concrete. 2. A composition obtained by containing a hydraulic cement, a formaldehyde resin precursor containing substantially no water, but producing water by a curing reaction, and, if necessary, an additive and / or a filler. A method for producing a concrete member, characterized in that a reinforced hardened body is previously installed inside a mold, and then concrete is cast into the mold to integrate the reinforced hardened body. 3. A composition containing a hydraulic cement, a formaldehyde resin precursor which is substantially free of water but produces water by a curing reaction, and optionally an additive and / or a filler. A method for producing a concrete member, comprising assembling a reinforced hardened body as a mold, and placing concrete on the mold to integrate the reinforced hardened body. 4. A composition obtained by containing a hydraulic cement, a formaldehyde resin precursor containing substantially no water, but producing water by a curing reaction, and, if necessary, an additive and / or a filler. A method for producing a concrete member, comprising: adhering a reinforced hardened body to hardened concrete with an adhesive to integrate the reinforced hardened body.