JP2000303690A - Method for forming concrete with high physical properties - Google Patents

Abstract

PROBLEM TO BE SOLVED: To conspicuously improve physical properties of concrete, such as strength, waterproofness, and life, by rapidly mixing powder containing a high water-absorptive resin as a main component from below ready mixed-concrete when the concrete is placed. SOLUTION: Equivalently mixed power containing a high water-absorptive resin, silica fume, and a powder waterproof agent is dispersed on a placement surface where bars are arranged, of a floor, a roof, or the like, and ready mixed-concrete is pumped up to be placed on the powder in a usual manner. At this time, the mixed powder is mixed into the concrete from a lower surface of the same. The high water-absorptive resin mixed thereinto from below absorbs surplus water content from a lower portion of the concrete, and therefore movement of the surplus water content in an attempt to upward escape is not generated, whereby a water channel therefore is not formed. Thus, physical properties such as strength, waterproofness, and life, of the concrete are conspicuously increased while using the same ready mixed-concrete material and the same placing system as conventional ones, and breathing is eliminated, whereby leveling is carried out earlier and workability is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for significantly increasing the strength, waterproofness, and other various physical properties of ordinary concrete using Portland cement.

[0002]

2. Description of the Related Art Conventionally, various methods have been employed to improve the physical properties of concrete. Excluding those that require extraordinarily expensive materials and those that involve technologies that do not fit into reality, basically only water reducing agents and waterproofing agents are appropriately selected, and they are actually used. At present, the physical properties of the concrete have not progressed at all since 2 to 30 years ago, but rather have deteriorated due to deterioration of the aggregate and mixing of much water for pumping up.

[0003]

SUMMARY OF THE INVENTION In view of the above situation, an object of the present invention is to provide means for dramatically improving various physical properties of concrete in a form that is realistic.

[0004]

In order to solve this problem, the present invention uses a super-absorbent resin already used for disposable diapers or a pozzolan material known as volcanic ash. However, although these have already been tried many times as a means of improving concrete, ordinary (known) methods of use have little effect and have many difficulties. The following solutions were found.

That is, the method is characterized in that at the time of placing the ready-mixed concrete, a powder mainly composed of a highly water-absorbent resin is rapidly mixed in from below.

[0006] The superabsorbent resin referred to here absorbs about 100 to 1000 times its own weight of water and becomes an agar-like gel without easily dissolving in water or inhibiting the hydraulic reaction. Means something like For example, various products such as crosslinked polyacrylic acid partially neutralized products are already commercially available.

The powder may be a single super absorbent resin,
In order to further improve physical properties and workability, other powders may be mixed with the powder. As the mixed powder, an inorganic material which has a relatively close specific gravity and is harmless to concrete is desirable, but a so-called pozzolan material is particularly effective. However, a powdery waterproofing agent may be added thereto.

Means for rapidly mixing the above-mentioned powder from below the ready-mixed concrete at the time of placing the concrete is to previously set the surface to be set (bottom surface).
The powder can be achieved by spraying or dropping the ready-mixed concrete onto the powder and pouring it together with the force of flow.

The appropriate amount of the powder to be applied is based on the amount necessary and sufficient to absorb the excess moisture in the ready-mixed concrete. Therefore, the varieties of the superabsorbent resin, the mixing ratio of the superabsorbent resin in the powder, the thickness of the concrete to be poured, and the like are the determining factors. 5 typical superabsorbent resins on the market
When applying a powder containing 0% to a 20 cm thick concrete, about 10 to 30 g / m ² is a standard,
Actually, it varies depending on the situation at the site, the moisture content of the concrete, and the combination with other technologies.

[0010] According to the results of the actual application, it was found that the application of the powder was not necessarily required to be performed at a high degree of uniformity.

[0011]

[Action] In order to ensure the fluidity required for casting, the ready-mixed concrete used in actual construction must mix a much larger amount of water than the amount required for the actual hydraulic reaction. However, the surplus water tries to escape to the outside before hardening and forms countless fine channels, which causes countless fine continuous voids (capillaries) in the hardened concrete. The water that escapes from the furnace evaporates and further loses the water required for the hydraulic reaction, which has been a fundamental cause of impairing the physical properties of concrete up to now.

However, in the present invention, immediately after the ready-mixed concrete is poured, the superabsorbent resin mixed in from below starts the action of sucking the excess water from below, thereby causing the excess water to move upward. Since the water channel is not formed due to the lack of water, and since the water other than the water necessary for the true hydraulic reaction is exhausted, the fine void occupied by the water disappears. It becomes extremely dense, which significantly improves physical properties such as strength and waterproofness.

Since the superabsorbent resin used in the present invention starts absorbing water after placing the ready-mixed concrete, it does not impair the workability at the time of kneading or placing. If the resin is sprayed on the surface to be driven in advance, the concrete can be sufficiently realized by the injection of the ready-mixed concrete by pumping or the force of falling or flowing.

[0014] Thus, it is possible to promote an upward escape channel as in the case where the resin is applied to the upper surface of the ready-mixed concrete, and it is not possible to exert water absorbing power as in the case where the resin is attached to the lower surface, or the gel pushes up the lower surface of the concrete. Without producing an extremely ideally reduced water concrete, it also prevents the formation of latencies on the concrete surface.

In addition, the resin that has absorbed water forms a gel and acts as a water curing, so that loss of necessary water due to evaporation is prevented.
Since the gels are small spheres that are independent and dispersed, they do not significantly impair strength and waterproofness unlike continuous voids.
In addition, since the concrete upper surface is covered with a dense cement paste instead of the latency, the required moisture is prevented from evaporating.

Further, when a resin obtained by mixing a pozzolanic material with the resin is used, it becomes an appropriate filler and improves workability. In addition, free calcium in concrete is combined with silicic acid to stabilize it, and And further improve the physical properties of concrete, such as by improving acid resistance.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS At a construction site of a reinforced steel concrete building, a highly water-absorbent resin (trade name: Sunwet IM-5000), silica fume, and powdery waterproof are placed on a placement surface such as a floor or a roof. 2 mixed powder of equal amount
0-30 g / m ^{2 is} sprayed, and then the ready-mixed concrete transported from the ready-mixed concrete factory is pumped up and poured as usual. At that time, the mixed powder is caught in from the lower surface of the ready-mixed concrete and mixed. After casting, level the top and cure as it is.

[0018] The concrete after hardening is 7 days after casting.
On both days 28 and 28, the strength increased almost twice, the surface latencies were extremely low, and the water-permeable and water-proof properties were extremely high. By the way, even if the concrete was filled with water of several tens of cm and made into a pool, there was no water leakage at all.

[0019]

As described above, according to the present invention, the physical properties such as the strength, waterproofness and durability of the concrete can be remarkably improved while using the conventional raw concrete material and the casting system as they are. . In addition, workability is improved, such as quicker leveling due to the elimination of breathing. In addition, since the latencies are eliminated and the vehicle body itself has a waterproof structure, the effect of shortening the construction period, reducing costs, and preventing pollution of dust and waste due to the elimination of waterproof means such as sheets and asphalt is enormous.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C04B 103: 44 111: 20

Claims (3)

[Claims] 1. A method for forming highly physical concrete, wherein a powder containing a superabsorbent resin as a main component is rapidly mixed in from below the ready-mixed concrete. 2. The method according to claim 1, wherein a pozzolanic material is mixed in the powder. 3. The method of claim 1, wherein the powder is sprayed on the surface to be cast in advance, and then the ready-mixed concrete is sprayed or dropped or poured together with the force of flow to form the high-concrete concrete. Method.