JPH0585852A - Method for producing porous concrete - Google Patents

Abstract

(57) [Abstract] [Purpose] Construction of concrete parts and concrete structures on porous concrete. [Structure] A gap forming material of a polymer that melts and shrinks by heating is previously mixed or buried in a site where a gap is to be formed in cement mortar, and then this concrete mortar is heated to accelerate its hardening. , The gap forming material is melted and contracted to form a gap.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing perforated concrete for constructing an arbitrary part of a concrete member or a concrete structure on the perforated concrete.

[0002]

2. Description of the Related Art If the concrete itself is a porous water-permeable concrete that is highly water-permeable as a concrete retaining wall for supporting the embankment, not only can the drainage mechanism of the embankment be improved, but also the number of steps for constructing drainage holes can be omitted. Moreover, if the above-mentioned permeable concrete is applied to a concrete paved road, it is possible to absorb rainfall and improve the walking performance of the road.
Moreover, the noise caused by the traveling vehicle can be absorbed and reduced.
Even in such water-permeable concrete that is permeable to gas and liquid, gaps such as capillaries and bubbles are surely formed at effective sites in the concrete, and at the same time, the concrete other than the gap is formed into a dense material. Can be said to be the most preferable method for producing or constructing porous concrete. From this point of view, as a conventional method of manufacturing or constructing porous concrete such as permeable concrete or porous concrete structure, foaming material such as alumina or silicon is mixed with concrete mortar to generate bubbles. There are used a method of forming voids, a method of filling coarse aggregates coated with cement mortar into a mold to cure and solidify the coarse aggregates, and secure porosity.

[0003]

However, according to the former method, the compounding ratio of the foaming material such as alumina or silicon to the concrete mortar is very small, and it is very important to secure the precision of forming the voids due to the congestion of the work. However, it is difficult to control the quality such as porosity and strength, and when the volume of concrete mortar increases, the bubbles formed by foaming or the dispersion of capillaries tend to become uneven. Also, according to the latter method,
Although the porosity of concrete is good, the viscosity of cement mortar is delicately controlled, and the strength of concrete is reduced. As described above, these conventional methods have drawbacks such as anxiety about strength even if the porosity can be secured, or a problem of porosity even if the strength can be secured. There is a strong demand for the development of mass-production method and construction technology for concrete. The present invention improves the conventional porous concrete having the above-mentioned various difficulties, or the manufacturing method and the construction method of the concrete structure, and makes it possible to arbitrarily control the porosity of the concrete and the shape and size of the voids. It is an object of the present invention to obtain a method for producing a porous concrete that reliably produces a water-permeable concrete having high quality porosity, high reliability, and less strength reduction.

[0004]

In order to achieve the above object, in the present invention, a concrete mortar is prepared by mixing or embedding a gap forming material made of a polymer having an appropriate shape such as granules, fibrous or mesh that melts and shrinks when heated. The first feature is to form a gap in the concrete by heating the concrete mortar and hardening the concrete mortar and accelerating melting and shrinking of the gap forming material. The second characteristic is to contain a metal, and the third characteristic is to electrically heat the concrete mortar.

[0005]

When a concrete mortar in which a gap forming material made of a polymer that melts and shrinks by heating is mixed or embedded, the hardening of the concrete mortar and the melting and shrinking of the gap forming material are promoted, and a gap is formed in the concrete. It is formed. When a metal such as iron powder or steel wire is contained in the gap forming material, the temperature increase in the concrete mortar is promoted by the heat conduction of the metal, the concrete mortar is hardened in a short time, and the gap forming material made of a polymer is formed. Melts and shrinks. Further, heating the concrete mortar with electricity, using electric heating such as high frequency heating, by appropriately adjusting the size and shape of the electrode, current density, etc., the concrete mortar is locally heated,
The distribution of voids inside the concrete member or concrete structure is controlled to a desired distribution.

[0006]

EXAMPLES FIGS. 1 (a), 1 (b) and 1 (c) schematically show examples in which the method for producing porous concrete according to the present invention is applied to the production of porous concrete members. The mold 1 is filled with concrete mortar 2 in which a gap forming body is mixed or buried. As the gap forming body, in the case of (a), polypropylene which is melted and contracted by heating the concrete mortar 2
A mixture of thermoplastic polymeric particulate gap-forming bodies 3 such as vinyl acetate is shown. In (b), concrete mortar 2 has the same thermoplastic polymeric fibrous shape as described above. A mixture of the gap formers 4 is shown. Further, in (c), concrete thermoplastic mortar 2 in which a thermoplastic polymer network gap forming body 5 similar to the above is embedded is shown.

By curing such concrete mortar 2 by a known autoclave, the temperature of the concrete mortar 2 rises and the hardening is accelerated.
In the process in which free water exists in the concrete mortar 2, the temperature of the concrete mortar 2 is maintained at the boiling point of water. When the hydration reaction of the concrete mortar 2 progresses and free water disappears, the temperature of the concrete mortar 2 rises above the boiling point of water. When a polymer having a melting point of 110 ° C. is used as the polymer of the gap forming bodies 3, 4, 5 and the temperature of the concrete mortar 2 becomes 110 ° C. or higher, the gap forming bodies 3, 4, 5 melt and shrink. As a result, voids, that is, gaps are formed in the places in the concrete mortar 2 where the gap forming bodies 3, 4, 5 were present, and porous concrete is manufactured.

2 (a), (b), and (c) of FIG. 2, in the above-described embodiment, as the polymer of the gap forming members 3, 4 and 5, iron powder, steel wire or other metal having good thermal conductivity is used. Examples are shown using composite thermoplastic polymers. That is, the particulate metal 6 is compounded in the particulate void-forming material 3, the metal wire 7 is compounded in the fibrous void-forming material 4, and the metal net 8 is compounded in the net-shaped void-forming material 5. Mixing or embedding these gap forming bodies 3, 4, 5 in cement mortar,
Then, if it is cured by an autoclave, the temperature of the concrete mortar 2 rises and the hardening is accelerated, and at the same time, the good heat of the metal, 6, 7, and 8 which is also compounded with the gap forming bodies 3, 4, and 5, respectively. The conductivity accelerates the temperature rise, shortens the time for melting and shrinking, and enables efficient production of porous concrete. Furthermore, when a void-forming material that is combined with a metal is used, especially in the case of a particulate or fibrous void-forming material, it becomes easier to adjust the specific gravity that affects the mixing property with cement mortar, workability, etc. with a metal having a large specific gravity. , The dispersibility of the pore former in the cement mortar is improved.

FIG. 3 shows an embodiment in which a water-permeable porous concrete retaining wall is constructed by applying an electric curing method instead of the heating curing method by the autoclave in the above-mentioned embodiment. In the figure, copper on the inner surface facing each other,
Electrically insulating form 10 such as a water-resistant plywood to which plate electrodes 9a and 9b such as aluminum are attached, or a plastic plate
Then, concrete mortar 11 mixed with the particulate and fibrous gap forming bodies 3 and 4 shown in FIG.
Then, the plate electrodes 9a and 9b are connected to a generator 12 having a commercial frequency or 1000 Hz, respectively.
A voltage is applied to 9b. As a result, the concrete mortar 11 is energized to generate Joule heat and heated, and at the same time, the hydration reaction is promoted and the hardening proceeds. In the early stage of hardening when the fluidity of the concrete mortar 11 was lowered, the applied voltage was adjusted to adjust the concrete mortar 11
When the temperature is heated above the boiling point of water, free water boils and bubbles are generated, and at the same time, the polymers of the gap-forming bodies 3 and 4 are melted and contracted to form a gap, thereby forming a retaining wall of porous concrete.

In the present embodiment, as shown in FIG. 4, if one plate electrode 9a is widened and the other plate electrode 9b is narrow and attached to the lower part of the electrically insulating frame 10, the current during energization is reduced. The density of the concrete mortar portion 13 in the range connecting the shortest distance between the electrodes is larger than that of other portions, and as a result, the mortar gap of the concrete mortar portion 13 between the plate electrodes 9a and 9b is formed. Go faster than the part. Therefore, when there is embankment on the side where the wide plate electrode 9a was formed in the formed retaining wall, the rainwater of this embankment penetrates through the perforated concrete of the concrete mortar portion 13 and the retaining plate having the narrow plate electrode 9b on the opposite side. Drainage can be made from perforated concrete at the bottom of the wall. That is, if electric heating is applied to the heating in the present invention, local heating can be performed by appropriately devising the dimension and shape of the electrode and the current density, so that the distribution of the gap inside the concrete member or structure can be arbitrarily controlled. You will be able to do it.

In the electric heating in this embodiment, if a generator of 10 KHz to 50 MHz is applied to the generator 12, high frequency heating such as induction heating and dielectric heating can be performed.
That is, in the case of a frequency on the order of KHz, the gap forming bodies 3 and 4 complexed with the metals 6 and 7 are selectively used by using, for example, a spiral inductor instead of the plate electrodes 9a and 9b. Can be induction heated. Also,
When the frequency is in the MHz order, the plate electrodes 9a and 9b are used to dielectrically heat the polymer of the gap forming members 3 and 4 and the concrete mortar 11, and the gap forming members 3 and 4 are also used.
It is possible to form a gap in the concrete mortar 11 by inducing heat generation by inducing discharge of the metals 6 and 7 and melting and shrinking the polymer of the gap forming bodies 3 and 4.

[0012]

As described above, the present invention heats concrete mortar mixed or embedded with a gap-forming material composed of a polymer that melts and shrinks by heating, hardening the concrete mortar and melting the gap-forming material, Since the gap is formed in the concrete by promoting the shrinkage, it is possible to control the porosity in the concrete by appropriately setting the mixing ratio of the gap forming material with cement mortar and the shape and dimensions of the gap forming material. The shape and size of the voids can be arbitrarily and reliably formed. Further, in the case of mixing or embedding a gap forming material containing a metal in a polymer in cement mortar, the thermal conductivity of the metal can accelerate the hardening of the concrete mortar and the melting and shrinking time of the gap forming material, The porous concrete can be efficiently produced, and the specific gravity of the metal is large, so that the dispersibility of the gap forming material in the cement mortar can be improved.
Further, in the conventional manufacturing method for consolidating aggregates coated with cement mortar, the size (grain size) of the aggregates is often based on a single grain size, so that it is unavoidable that the strength of concrete decreases. However, according to the present invention, since the irregular gap forming material is mixed with the mortar having the usual composition, the strength reduction can be prevented as much as possible. Further, in the case of using an electric heating method such as electric current heating or high frequency heating for heating concrete mortar, since a local part of the concrete member or the concrete structure can be constructed on the perforated concrete, concrete having various uses can be used. It is possible to expand the range of application of the members and structures of, and to benefit the multifunctionalization of concrete.

[Brief description of drawings]

FIG. 1 (a) is a partial cross-sectional view showing a state in which concrete mortar mixed with a granular gap forming material is filled in a mold, and (b) is a fibrous gap forming material mixed. Partial cross-sectional view showing a state where concrete mortar is filled in the mold, (C) is a partial cross-sectional view showing a state where concrete mortar in which a net-like gap forming material is embedded is filled in the mold Is.

FIG. 2A is a cross-sectional view showing a state where metal powder is mixed with a granular gap forming material, and FIG. 2B is a cross-sectional view showing a state where metal wires are combined with a fibrous gap forming material. (C) is a cross-sectional view showing a state in which a metal net is combined with a mesh-shaped gap forming material.

FIG. 3 is an explanatory diagram in the case of constructing a perforated concrete retaining wall using an electric curing method as a heating method for concrete mortar.

FIG. 4 is an explanatory view of another embodiment in which a porous concrete retaining wall is constructed by using an electric curing method as a heating method for concrete mortar.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Mold frame 7 ... Metal wire 2, 11 ... Concrete mortar 8 ... Metal net 3 ... Particulate gap forming bodies 9a, 9b ...
・ Plate electrode 4 ・ ・ ・ Fibrous gap forming body 10 ・ ・ ・ Electrically insulating frame 5 ・ ・ ・ Reticulated gap forming body 12 ・ ・ ・ Generator 6 ・ ・ ・ Particulate metal 13 ・ ・ ・ Priority heating Concrete mortar part

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location C04B 14:34) 2102-4G (72) Inventor Yumoto Emoto 3 39 Nakamura, Nerima-ku, Tokyo No. 13 Ciel Royal M-206

Claims (3)

[Claims] 1. A concrete mortar in which a gap-forming material made of a polymer having an appropriate shape, such as granules, fibers, or nets, which melts and shrinks when heated is mixed or embedded, is heated to cure the concrete mortar and to form the gap-forming material. A method for producing perforated concrete, characterized in that a gap is formed in the concrete by promoting melting and shrinkage. 2. A concrete mortar containing a metal such as iron powder and a steel wire and mixing or embedding a gap-forming material made of a polymer having an appropriate shape such as granules, fibrous or mesh that melts and shrinks when heated. A method for producing a perforated concrete, which comprises heating to cure the concrete mortar and promote melting and shrinkage of the gap forming material to form a gap in the concrete. 3. A concrete mortar containing a metal such as iron powder and a steel wire, and mixed or embedded with a gap forming material made of a polymer having an appropriate shape such as granules, fibrous or mesh that melts and shrinks when heated. A method for producing a perforated concrete, characterized in that a gap is formed in the concrete by electrically heating to accelerate hardening of the concrete mortar and melting and shrinking of the gap forming material.