JPH10258406A - Concrete having property changeable by magnetism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the strength and durability of a reinforced concrete by a method wherein a magnet, which can magnetize magnetic bodies, is mounted inside and outside a concrete, in at least some part of aggregates of which the magnetic bodies are included and which is not yet solidified, and fixed or moved. SOLUTION: A magnetic material-added concrete, some part of the fine or coarse aggregates of which consists of ores including slugs and iron sand, metals, artificial magnetic materials and their composite materials, is put in a container. When a magnet 5 is externally contactedly fixed to the container, the magnetic aggregates are magnetized and applied with a force attracting to the magnet 5, resulting in compressing a viscous concrete 1 between the magnetic aggregates and the container, consequently enheightening the viscosity of the concrete and densely collecting some part near the magnet 5 of the magnetic aggregates around the magnet 5. On the other hand, t through the movement and stoppage of the magnet 5, a flowing force, the direction of which is varied, is given to a magnetized concrete. When the magnet 5 is vibrated, the concrete, which is not yet solidified, vibrates together with the magnetic aggregates, resulting in dispersing the air within the concrete and acting so as to prevent accumulated bubbles from generating between the inner surface of the container and the concrete.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to concrete having excellent workability, high strength, durability, and high magnetic shielding properties, which is used in civil engineering work sites and the like.

[0002]

2. Description of the Related Art Forming, spraying, and prepacked concrete methods are known as concrete works. Concrete is compacted using a vibrator or the like in order to improve strength, water tightness and durability in the course of hardening. There is also a concrete mortar injection method using an injection pipe in a borehole as a rock injection method. On the other hand, recently, in the field of architecture, research has been conducted to shield structures from magnetism. Conventionally, iron ore is used as a heavy concrete material and steel fiber is used as a fiber reinforcing material. However, the original purpose of these materials is to increase the weight and strength of concrete by the material itself after hardening. The present invention
It is characterized by the fact that the main means is to use the magnetism of the aggregate, and that the concrete that has not yet set is targeted for action. In addition, in the technology for handling a magnetic material, a magnetic fluid including colloid particles in which ultrafine ferromagnetic particles are added to an organic solvent together with a surfactant is dispersed. In the present invention, the magnetic material is a material having a relatively large shape, and the behavior in the concrete that is not yet solidified in which consistency, plasticity, etc. becomes a problem, and the magnetic material itself after curing is important as an aggregate. It is used for a different purpose such as a magnetic fluid.

[0003]

Heretofore, it has been difficult to artificially change the properties of concrete after blending into artificially required properties. In particular, in the case of placing concrete in a narrow place due to a complicated form shape or dense arrangement of reinforcing bars, it is difficult to sufficiently compact the concrete by a vibrator. As a result, there are problems such as generation of air bubble accumulation voids and unfilled voids in the concrete, and non-adhesion between the reinforcing steel and the concrete. In the construction, there are still problems such as clogging of a chute in casting work, leakage of concrete from a gap between formwork, and control of concrete fluidity at the time of concrete pouring. Furthermore,
The spraying method has a problem of rebounding a large amount of concrete, and the upward rock injection method has a problem of anchor non-adhesion due to adhesive mortar leakage. On the other hand, in the field of construction, research is being conducted to solve the problem of magnetic shielding. Also, in pavement work, there is a problem of wear of the pavement surface and the pavement marking surface.
An object of the present invention is to provide concrete capable of solving these problems.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem by applying a magnetic force to unconsolidated concrete containing magnetic aggregate. Here, the concrete is obtained by coagulating aggregate with a binder, and the binder is cement paste, asphalt, synthetic resin, paint, and the like.

[0005] Concrete magnetic aggregates use magnetizable slag, ores containing iron sand, metal, artificial magnetic materials, or composite materials thereof as fine aggregates and coarse aggregates.

The magnet is made of a material which is magnetically induced by an electromagnet, a permanent magnet, or both, which can change the magnetic force by changing the direction and strength of the coil current.

The permanent magnet is fixed or moved inside and outside the concrete, and the electromagnet is used by fixing, moving or changing the coil current.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS When a magnetic substance-added concrete is placed in a container and a magnet is fixed to the container, the magnetic aggregate is magnetized and receives a force attracted to the magnet.
The viscous concrete receives a compressive force between the concrete and the container via the magnetic material, and the viscosity increases. In addition, some of the magnetic aggregate near the magnet will cluster around the magnet. On the other hand, the movement and stoppage of the magnet imparts a changed flow force to the magnetized concrete mixed with magnetic material. Due to the vibration of the magnet, the concrete that has not yet set vibrates together with the magnetic aggregate, and the air inside the concrete is dispersed, which serves to prevent the formation of accumulated air bubbles between the inner surface of the container and the concrete.

[0009] When a magnet is placed in contact with the outside of the mold containing the hardened magnetic aggregate-mixed concrete, the magnetic aggregate attracts the magnetic aggregate toward the form to which the magnet is attached. The concrete between the and the formwork is compressed,
Actions such as high density and high initial strength and high electromagnetic shielding properties are provided.

[0010] When the concrete containing magnetic aggregate is poured using the reinforcing bar, the density of the aggregate near the surface of the reinforcing bar increases due to the magnetization of the reinforcing bar. Works to increase the strength and durability of reinforced concrete by increasing the adhesive strength of the steel and protecting the corrosive corrosive bars.

When leakage of the magnetic aggregate concrete is found from the gap of the formwork or the like, a magnet is attached near the leakage point,
The application of the magnetic force acts to stop the leakage of the concrete due to an increase in the viscosity of the concrete or a temporary setting of the magnetic force acting portion. Also, if a magnet is installed inside or outside the concrete flow pipe used during casting or inside or outside the formwork, the flowing concrete works so as not to flow beyond the position of the magnet as a boundary.

In the case of the sprayed concrete, the magnet containing the magnetic aggregate is adhered to the sprayed surface by magnetizing the sprayed net, so that the rebounding particles generated by the collision are sucked into the sprayed net, so that only the concrete with less rebound can be obtained. Instead, the sprayed concrete is sucked and compressed by a magnetically induced spraying net together with the magnetic aggregate, and works to produce dense and high-strength concrete.

[0013] A magnet is installed at a place where the concrete pouring chute is likely to be clogged, and a force is exerted by the movement of the magnet so that a flow force is generated in the magnetic aggregate-added concrete, thereby preventing the chute from being clogged.

In the case of prepacked concrete, when a coarse aggregate is filled and mortar is injected and then a magnetic force is applied from the outside of the concrete form or the inside of the concrete to vibrate, the concrete acts to increase the packing density by the vibration.

In pouring concrete mortar mixed with a magnetic material into a rock upward hole, the mortar is condensed by attaching a magnet to the hole outlet, and a flow-out preventing action is provided.

[0016]

An embodiment will be described with reference to the drawings. Slag (hereinafter referred to as HG) containing an iron oxide component obtained as a by-product in the electric furnace steelmaking process is used as an aggregate, and is mixed with water 15
9, cement 265, sand 500, HG fine aggregate 465, crushed coarse aggregate 657, HG coarse aggregate 588, admixture 1.59
Magnetic aggregate concrete (unit: kg / m ³ ) (1)
Was placed in a container as shown in FIG. The container has four sides (2
a), (2b), (2c), (2d), upper surface (3a),
The 2a surface of the rectangular parallelepiped container having the bottom surface (3b) is made of glass, and the other side surface is made of plywood having a thickness of 2 mm.
An iron rectangular parallelepiped (4) is attached in contact with a) and the side surface (2c), and an injection hole is provided on the upper surface. When a magnet (5) of 1000 gauss is brought into contact with the outer surface of the side surface (2c) and vibrated in the direction of the arrow, the inside (6) of the side surface (2c) and the outer surface (4a) of the rectangular parallelepiped (4) in the concrete (4a). The distribution of the magnetic aggregate HG was examined. The investigation was carried out by visually inspecting the glass surface and taking out the concrete from the container after curing, and examining the surface roughness and the concrete cross-sectional composition. In addition, this distribution was compared to the inner adjacent concrete (7) on the opposite side (2d) to the magnet. As a result, concrete (6) and (4a part)
In the sample, the density of the HG material component was higher than that in the conglomerate (7). The depth of scratching by the knife as a measure of hardness comparison was shallower in the concrete (6) portion and the concrete (4a) portion than in the concrete (7).
Also, traces of bubbles having a diameter of about 1 mm were found on the concrete surface on the side surface (2d), but were not found on the side surface (2c).

The embodiment shown in FIG. 2 (plan view) shows an adhesion test between concrete and a reinforcing steel bar when an external force is applied by an electromagnet. Inner diameter 8mm, outer diameter 13.8mm, length 120mm
The distance between the two glass tubes (8) is set to 5 mm,
One side of the glass box (9) stands upright with the glass surface (10) in contact with the glass surface (10), and is mixed with water 159, cement 265, sand 50
0, HG fine aggregate 465, crushed coarse aggregate 657, HG coarse aggregate 588, and magnetic aggregate concrete (11) made of admixture 1.59 (kg / m ³ ) are put into the pipe until the pipe is hidden. Create a cavity (12) surrounded by glass and 10,000
A Gaussian magnet (13) was reciprocated up, down, left and right along the glass surface (10) to investigate the possibility of intrusion into the concrete cavity (12). As a result, the cavity (12) was completely filled.

The embodiment shown in FIG. 3 is an experiment in which a dry HG aggregate (15) having a particle size of 2 to 2.5 mm without mixing cement into a channel steel plate (14) is poured from a hopper (16) into a receiving box (17). Is shown. The material natural flow angle of the channel steel plate (14) is 3
It was 7 ゜. Thereafter, a belt (18) with a plate magnet is attached in contact with the back surface of the grooved steel plate (14), and is continuously moved in the flowing direction of the aggregate (15) as shown by the arrow, whereby the dry HG aggregate (15) is obtained. ) Indicates a grooved steel plate (14) with a slope of 3
It was confirmed that the flow did not stop even when the temperature reached 0 °, and the flow became easy due to the magnetic force.

FIG. 4 shows an HG having an average particle size of 20 mm.
The experiment of dense packing of concrete by prepacked method including aggregate is shown. Magnetic coarse aggregate (2) is placed in a vertical glass tube (19).
0) was filled up to the mouth. After the mortar injection of 40% by weight of the magnetic fine aggregate, an electromagnetic winding (21) was added to the tube (19).
(22) and (23) are attached in three places, and the power supplies (24C), (24B), and (24B) are arranged so that the magnetic force is interrupted in the order of the winding (23), the winding (22), and the winding (21). (24
The current of A) was interrupted one after another, and the change in the volume of the aggregate was examined. The upper surface of the HG aggregate in the glass tube (19) has settled to the position of the dotted line (25), and the aggregate volume has been reduced by about 6 from the initial measurement.
% And the packing density was increased.

The embodiment of FIG. 5 shows a concrete spraying experiment. A plywood (28) was curved and attached to a stay (27) on a beam (26) to simulate a tunnel roof. Plywood (2
8) A mesh iron wire (29) in which a 3 mm steel rod was formed into a grid of 15 mm × 15 mm was stretched. An electromagnet (30) is attached thereto to generate a magnetic force of 10,000 gauss, and a material hose (34) is formed using a spray nozzle (32) and a compressed air pipe (33).
, Water 159, cement 265, sand 50
0, HG fine aggregate 465, crushed coarse aggregate 657, HG coarse aggregate 588, spray-coated layer (31b) made of magnetic aggregate mixed concrete (31) of quick-setting aggregate 80 (unit kg / m ³ ). . Thereafter, spraying was performed under the same conditions except that no magnetic force was applied. In both experiments, the amount of rebound (31a) was measured, and the former had a rebound of about 12% and the latter had a rebound of 32%.
%.

The embodiment of FIG. 6 shows an experiment for forming a protective structure of silicon carbide particles on the surface of a magnetic aggregate-added concrete (35) in which hard and brittle silicon carbide particles are mixed by 10% (by weight).
Magnetic aggregate concrete (35) containing water 159, cement 265, sand 500, HG fine aggregate 465, crushed coarse aggregate 657, HG coarse aggregate 588, and admixture 1.59 (unit kg / m ³ ). ) Was placed in a transparent plastic container (36), and after smoothing the surface (37), a 10,000 gauss permanent magnet (38) was reciprocated as indicated by an arrow until the concrete hardened. Thereafter, the surface portion was sampled, and the number of magnetic materials exposed on the surface per unit area was measured. Thereafter, the magnetic material on the surface when the magnet was not used was cured under the same conditions, and the number per unit area of the magnetic material was measured in the same manner as the former. From the comparison of the two magnetic material components, it was confirmed that the HG aggregate and the silicon carbide particles were uniformly dispersed in the surface portion by the magnetic force, and a surface protection layer of brittle silicon carbide particles was formed.

FIG. 7 shows an embodiment of a wear-resistant HG aggregate powder 40.
An experiment of marking the surface of a pavement material (40) with a pavement paint (39) to which weight% is added is shown. After the marking, the surface was dried while reciprocating as indicated by an arrow while applying a magnetic force with a magnet (41) near the surface. Further, marking was performed under the same conditions without using a magnet, the surface sample was cut out, and the cross section was observed. The number occupied by the magnetic materials on both marking surfaces was measured with a magnifying glass. As a result, in the former, HG aggregate surface concentration (39a) not found in the latter was observed. The figure below is an enlargement of part A.

The embodiment shown in FIG. 8 shows an experiment for preventing outflow of cement mortar in a work of injecting a borehole facing rock. Drill upward from the inner wall of the bedrock (42), insert a 10000 gauss magnet (46) into the entrance of the borehole (43), and fill the borehole (43) with water 6 using the injection pipe (44).
7. Mortar (45) made of cement 150 and HG fine aggregate 330 was injected. The magnets (46) reduced the flowability of the lost injected cement, clogging the boreholes and preventing mortar loss.

The embodiment of FIG. 9 shows an experiment for preventing concrete from leaking when concrete is driven using a formwork. Mix with water 159, cement 265, sand 500, H
G fine aggregate 465, crushed coarse aggregate 657, HG coarse aggregate 58
8. The magnetic aggregate concrete with the admixture of 1.59 (unit kg / m ³ ) is 0.7 m from the bottom, 10 mm wide and 2 mm long.
The concrete (49) having a crack (48) of 00 mm was poured, and the concrete leaked from the crack (48). Next, a 10,000 gauss plate magnet (47) was cracked (4).
8) Fixed close to. As a result, the viscosity of the concrete increased, and the leakage stopped.

The embodiment of FIG. 10 shows an experiment for controlling the flow of concrete in a form. 0.3m height side plate (5
0a), (50b), (51a), and a mold using (51b), the width of the side plates (50a) and (50b) is 0.7 m,
The width of the side plates (51a) and (51b) is set to 0.2 m, and the height of the side plate (50a) is 0.7
A 1200 gauss bar magnet (54) m, 0.2 m wide was mounted vertically. From the concrete insertion port (52) on the upper surface of this formwork, the mixture was mixed with water 159, cement 265, sand 500, HG fine aggregate 465, crushed coarse aggregate 657, HG coarse aggregate 588, and admixture 1.59 ( Magnetic aggregate concrete (55) in a unit of kg / m ³ ) was injected. As a result,
Concrete has no magnets (5
4) There was no outflow to the plate (51b) side with the passing line (53) as the boundary. When the magnetic force is removed, the concrete becomes a board (5
1b).

The embodiment of FIG. 11 shows an experiment for controlling unset concrete passing through a concrete hose.
Rubber hose with an inner diameter of 75 mm inclined 45 degrees from horizontal (5
6) In the formulation, water 159, cement 265, sand 50
0, magnetic aggregate concrete (57) made of HG fine aggregate 465, crushed coarse aggregate 657, HG coarse aggregate 588, and admixture 1.59 (unit kg / m ³ ) was allowed to flow naturally in the direction of the arrow. . Wrap an electromagnetic winding (58) around the hose (56),
The flow of concrete (57) was completely stopped as a result of generating a magnetic force of 10,000 Gauss. It was confirmed that the flow of the concrete (57) could be stopped or dropped again by increasing or decreasing the current of the power supply (59).

The embodiment of FIG. 12 shows an experiment of magnetic shielding.
A non-solidified concrete mortar (61) of 40% by weight of magnetic fine aggregate was wound around the glass tube (60) to a thickness of 20 mm, and a rod magnet was put inside the glass tube and cured.
Pull out the bar magnet and wind it outside the hardening mortar (62)
And an ammeter (64) was attached to the winding end. The magnet (63) was placed in a glass tube and moved in the direction of the arrow to measure the current of the winding. The same experiment was performed in an apparatus using a mortar cured without using a magnet. As a result, the former was found to have a smaller winding current and a higher magnetic shielding property than the latter.

[0028]

Since the leaf of the present invention is constituted as described above, when a magnetic aggregate is mixed under concrete that has not yet set and a magnetic force is applied from inside and outside, vibration and movement of the magnetic material due to the magnetic force are caused. , Fixing and condensation phenomena occur.
Therefore, the following effects can be obtained.

When hardened concrete near the rebar due to the magnetic induction of the rebar hardens, the concrete becomes compacted by compression and the strength is improved. Therefore, the bonding strength between the rebar and the concrete is increased, and the rebar has a protective effect against deterioration. Is generated, and concrete that improves the strength and durability of reinforced concrete is obtained.

The viscosity of the concrete that has not yet solidified due to the cohesion due to the magnetic force increases, the flow direction of the concrete can be changed at the time of placing the concrete in the formwork, the leakage of the concrete can be stopped, and the flow can be reduced without using a barrier material. The concrete to stop is obtained.

When the mortar leaks from the mouth of the injection hole by the injection method, a concrete can be obtained in which a magnet can be installed in the hole to prevent the loss of outflow.

The air in the concrete is dispersed by the magnetic vibration, so that concrete having a smooth surface without air hole marks on the so-called formwork concrete surface can be obtained.

The concrete poured into the formwork in which the reinforcing bars are densely arranged flows by giving a vibration by magnetic force.
A tightly packed concrete can be obtained without using a fluidizing material.

The concrete feeding chute can obtain concrete which can eliminate the clogging of the chute by the vibration or movement of the magnetic force and can temporarily stop the flow.

[0035] Prepacked concrete using a magnetic material as an aggregate can increase the packing density by vibrating or moving magnetic force, so that high strength concrete can be obtained.

In the sprayed concrete, a wire mesh is stretched on the sprayed surface, and magnetic induction of the wire mesh causes magnetic attraction to generate concrete attraction, thereby reducing rebound. Further, dense and high-strength concrete is attracted by the attraction of the magnet to the wire mesh. can get.

In the case of pavement concrete, a magnetic material having high hardness and ductility is used to cause a magnetic force to act on the surface to obtain pavement concrete having a large surface hardness.

In pavement marking, when a magnetic material having a high hardness is added to the paint and a magnetic force is applied to the surface in the finishing step, the magnetic material in the paint gathers on the surface to obtain a highly durable marking material.

By using a magnetic aggregate and concentrating the magnetic material by magnetic force, concrete with high magnetic shielding properties can be obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an embodiment showing a state of a concrete boundary surface.

FIG. 2 is a plan view showing an example of concrete intrusion.

FIG. 3 is a sectional view showing an example of a flow of concrete.

FIG. 4 is a view showing an embodiment of a prepacked concrete aggregate.

FIG. 5 is a view showing an example of shotcrete.

FIG. 6 is a longitudinal sectional view showing an example of wear-resistant pavement.

FIG. 7 is a longitudinal sectional view showing an embodiment of a pavement marker.

FIG. 8 is a longitudinal sectional view showing an example of mortar injection.

FIG. 9 is a view showing an embodiment of a concrete leak stop.

FIG. 10 is a diagram showing an example of concrete flow in a formwork.

FIG. 11 shows an example of concrete flow in a hose.

FIG. 12 is a diagram showing an example of magnetic shielding.

[Explanation of symbols]

1, 15, 20, 31b, 35, 40, 45, 55, 5,
7,61 Concrete 4,13,18,30,38,41,46,47,5
4, 63 magnets 21, 22, 23, 58, 62 coils

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C04B 14:34) 111: 90

Claims (5)

[Claims] 1. A concrete whose property is changed by attaching or moving a magnet capable of magnetizing the magnetic material inside and outside of concrete that has not yet hardened yet contains a magnetic material in at least a part of the aggregate. 2. The concrete according to claim 1, wherein the position of the magnet relative to the holes, tubes, grooves and containers through which the concrete passes is a distance at which the magnetic force effectively works on the magnetic material. 3. The concrete according to claim 1, wherein the position of the magnet relative to the concrete surface or the boundary surface between the concrete and another substance is a distance at which the magnetic force effectively works on the magnetic material. 4. The concrete according to claim 1, wherein the position of the magnet relative to the concrete spraying surface is a distance at which the magnetic force effectively acts on the magnetic material. 5. The concrete according to claim 1, wherein the position of the magnet relative to the reinforcement is a distance at which the magnetic force effectively acts on the magnetic material through the reinforcement.