KR100883141B1 - Water absorbing type retentive concrete composite materials and it's manufacturing method - Google Patents

Abstract

The present invention relates to a repaired concrete composition. The present invention relates to a water-retaining concrete composition consisting of a water-retaining additive, an absorbent polymer, and a water-soluble polymer in cement and particle size-adjusted aggregate, wherein the water-absorbing polymer is 0.001 to 5 parts by weight based on 100 parts by weight of cement, and the water-soluble polymer is cement 100 0.01 to 10 parts by weight to the composition of the water-absorbing polymer in the addition of the delayed wetting expansion of dextrin, glycerin or a mixture thereof is composed of 0.001 to 5 parts by weight based on 100 parts by weight of the absorbent polymer To provide a concrete composition. According to the present invention, the absorbent polymer absorbs the water in the hardened concrete to reduce the water cement ratio in the concrete, and the water cement ratio around the pores due to the pore formation while absorbing water is lower than the original compounded strength. The strength is increased. The present invention relates to a revolutionary invention that can reduce the heat island phenomenon occurring in the summer.

Water-retaining concrete, concrete products, absorbent polymers, water-soluble polymers, wet expansion retardants, heat island prevention

Description

Water-repellent concrete composition and manufacturing method of water-retaining concrete using the same {Water absorbing type retentive concrete composite materials and it's manufacturing method}

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows typically the action of an absorbent polymer in the repair concrete of this invention.

Figure 2 is a graph showing the results of measuring the surface temperature change according to the infrared lamp irradiation time of the repaired concrete prepared according to an embodiment of the present invention.

The present invention relates to a composition of water-retaining concrete, and more particularly, to a water-retaining concrete composition having easy workability and high strength and durability.

0.001 to 5% by weight of the absorbent polymer and 0.01 to 10% by weight of the water-soluble polymer in the cement, aggregate and water-retaining inorganic materials are dextrins, glycerin, and The present invention relates to an invention for producing water-retaining concrete by adding 0.01 to 5% by weight of the absorbent polymer.

Generally, in order to obtain water-retainability in concrete as a manufacturing method of water-retaining concrete, materials for repairing granules of aggregates or repairing tiles, ceramics and shells, porous lightweight aggregates, diatomaceous earth, refractory clay, waste foundry sand and bentonite, etc. It is manufactured by adding water-retaining materials such as charcoal, lightweight foam concrete (ALC), pearlite (JP-2004-108027), zeolite, sponge, etc. It is common to produce pores to produce concrete. In addition, there is a method of manufacturing a water repellent block using asbestos-containing building material waste or sewage sludge incinerator (Japanese Patent Publication No. 2002-167888). However, the concrete manufactured by these methods is porous concrete, but the strength is low, so that the reinforcement of a separate reinforcement or structural shape, etc., or a structure made of another material of two or three layers has the disadvantage of lowering productivity and manufacturing cost.

In addition, in Japanese Patent Application Publication No. 2003-239207, a water-soluble packaging aggregate and a binder in which a water-soluble polymer is dispersed in a polyurethane foam, and water such as rainwater is absorbed into the concrete, and the product is exposed to sunlight and the temperature rises. There is a way to prevent heat island phenomenon by evaporation of water while draining from the water. However, this method is very difficult for the process of installing polyurethanes with water-dispersible polymers dispersed at the center of the product during manufacturing, and the productivity is reduced. Problems are easily broken or weak durability

The present invention is to solve the above problems, it is an object of the present invention to provide a water-retaining concrete composition and a method for producing the same that can improve the workability and strength.

In order to achieve the above technical problem, the present invention is a water-retaining concrete composition consisting of a water-retaining additive, water-absorbing polymer, water-soluble polymer in the cement and the particle size adjusted aggregate, the water-absorbent polymer is 0.001 parts by weight to 5 parts by weight of 100 parts by weight of cement 0.001 parts by weight to 5 parts by weight of dextrin, glycerin or a mixture thereof as a wet expansion retardant of the absorbent polymer to a composition in which 0.01 parts by weight to 10 parts by weight of water-soluble polymer was added to 100 parts by weight of cement. It provides a repairable concrete composition, characterized in that consisting of parts by weight.

In addition, the composition of the present invention may include 3 to 15 parts by weight of bottom ash as a water-retaining additive for 100 parts by weight of cement.

Hereinafter, the present invention will be described by explaining preferred embodiments of the present invention with reference to the drawings.

When absorbent polymer is used, water absorbs when concrete is mixed and absorbent polymer expands to play the role of ball bearing to improve the workability of concrete, thereby reducing the number of units in concrete, thereby increasing its strength. In addition, the water-soluble polymer is dissolved in water to improve the viscosity of the cement paste, and the improved viscosity of the cement paste improves the adhesive strength with the aggregates, thereby improving the bending strength, which is the greatest weakness of the porous and water-retaining concrete.

However, if concrete is manufactured by this method, the absorbent polymer absorbs water at first and expands 5 ~ 1000 times, and the workability is sharply lowered, so that the product is not molded, or the surface of the product is poor after molding, resulting in uneven surface phenomenon. The disadvantage is that the value as a product and the product dimensions are incorrect. As a result of finding out the cause of this, the absorbent polymer is deteriorated in concrete workability due to the rapid combination of water with concrete in the early stage of concrete mixing, and the absorbent polymer expands while absorbing water before it hardens after forming, resulting in inaccurate product dimensions and bumping the surface of concrete. I found something that makes it work.

The present inventors have studied materials that delay or inhibit the reaction of water absorbent polymers with water and have found that dextrin and glycerin have this function. In general, the absorbent polymer has a property of absorbing and expanding water 5 to 1000 times by weight. Dextrin and glycerin have been found to delay the hydration of cement but also to delay or inhibit the wet expansion of the absorbent polymer.

Wet expansion retardants of these absorbent polymers react with water at the beginning of the mixing to delay or inhibit the expansion from 5 to 1000 times from concrete mixing to molding of concrete products, resulting in 10 to 120 minutes of molded concrete products. At this point, the absorbent polymer gradually absorbs and expands the water in the concrete and absorbs the water in the surrounding concrete at the point of maintaining the magnetic shape (about 2 to 8 kg / cm2). The inventors found that the wet expansion retardants, glycerin and dextrin, were first adsorbed on the surface of the absorbent polymer to inhibit the expansion while reacting with water, but gradually dissolved in the mole, reducing the delay effect until 10 to 120 minutes.

As a result, the pores formed by the absorbent polymer expansion reduces the water cement ratio of the surrounding concrete, and condenses the surrounding concrete to make the concrete dense, thereby improving the strength of the concrete. Also, after forming the product, water absorbs and expands gradually in the concrete while digging and filling the pores such as capillaries, and when the water evaporates after curing or placing the product, the absorbent polymer shrinks to form voids. As soon as they meet, they form a capillary channel that absorbs it, and it is found that it can be used as a channel for storing water by forming a fine capillary tube with little loss of strength and also discharging the water to the outside.

 That is, the absorbent polymer spreads out like a capillary tube like a protrusion and absorbs water quickly, while it releases water gradually in the form of water vapor when it is released, thereby increasing water-retainability without causing a decrease in strength and gradually releasing water. It is possible to greatly reduce the heat island phenomenon.

This is shown in the schematic diagram as shown in Figure 1, after the water-absorbing polymer is expanded after absorbing the water absorbed in the concrete after the production of water-permeable concrete according to the present invention, the surrounding concrete is water cement ratio is lowered to improve the strength and the expansion of the absorbent polymer Due to the consolidation effect, the surrounding tissue becomes dense. In particular, the bending strength is increased by reducing or eliminating pores that greatly affect the bending strength, and the water-soluble polymer is firmly bonded to the interface between the aggregate and the cement, thereby increasing the bending strength. It is a principle.

This is a breakthrough invention that recently found out that it plays the same role as orphan tex in textiles.

As described above, the present invention is a revolutionary invention that contributes to improving the flexural strength, which is the biggest difficulty in producing water-retaining concrete, to improving water-retainability, and to reducing heat island phenomenon due to the release of water vapor absorbed by solar radiation.

It is preferable that the absorbent polymer is spherical so as to meet with water and expand 5 to 1000 times in concrete to act as a ball bearing. The water-soluble polymer is dissolved in water to increase the viscosity of the cement paste, thereby increasing the bonding strength with the aggregate, thereby improving the strength, reducing the dry shrinkage of concrete, and improving workability by improving consistency.

Herein, the water absorbent polymer is one or more selected from the group consisting of polyacrylates and derivatives thereof, polyethylene oxide derivatives and absorbent polyurethanes, and as the water-soluble polymer, polyvinyl alcohol, carboxymethyl cellulose, hydroxyethyl At least one selected from the group consisting of cellulose is used.

Meanwhile, conventional water-retaining concrete uses lightweight foamed concrete powder, pottery, waste vortex, zeolite, diatomaceous earth, refractory clay and the like as water-retaining additive. However, the inventors have found that the bottom ash can be used as a conventional water-retaining additive.

Fly ash from coal-fired power plants is used as a mixture of cement and concrete, but bottom ash, a residue left on the floor, is being treated as industrial waste. If the bottom ash is conservative in its effective utilization studies, it can be used as a conservative additive material for the manufacture of water-repellent concrete.

Bottom ash was found to have excellent water retention capability when added 5 to 15 parts by weight based on 100 parts by weight of cement. If it is less than 5 parts by weight, the water-retaining capacity is lowered, and thus the role as a water-retaining concrete product is not available, and if it is added more than 15 parts by weight, the strength is lowered and the performance as a product cannot be exhibited. Most preferably exhibits the best effect in the range of 7 to 10 parts by weight.

(Examples 1-6)

Some of the results of the experiment to confirm the invention described above are as follows.

For cement, Ssangyong Cement Co., Ltd., usually used Portland cement was used, and aggregate was used as aggregate for the particle size through the mixing test in advance so that the porosity was 26% using Okcheon acid gravel and sand. Ash and ALC shredders were used, polyacrylic acid was used as the absorbent polymer, and polyvinyl alcohol was used as the water-soluble polymer. Experiments were conducted with the formulations shown in Table-1, and the results are shown in Table 2. In the test method for repair capacity (rate), 5 × 5 × 5cm mortar specimens were cured in 20 ± 2 ℃ water for 3 days, and the water retention rate was measured by dry weight after drying for 24 hours in 105 ± 5 ℃ dryer under water. The equation is

% Repair = [(Function Weight-Absorbed Weight) / Absorbed Weight] * 100

As a result of this test, the amount of unit decreased with the addition of water absorbent and water-soluble polymer, and the flexural strength was improved, and the water holding capacity was also increased. Thus, the present invention can increase water holding capacity by 30 ~ 80% than existing water-soluble concrete products. In addition, whip strength is an excellent invention showing the strength of 45㎏ / ㎠, the road standard compared to 25 ~ 33㎏ / ㎠ for the general water-retaining products.

In addition, the test was performed as follows to determine the heat island effect (Heat island) of the present invention. The test package was cured at 60 × 60 × 10 cm in size and blended as shown in Table 2. The specimens were cured in air for 1 day and then cured in 20 ± 2 ° C. for 7 days. Using this device, an infrared lamp was installed 40cm above the surface of the specimen, and when the temperature was 33 ℃ in summer, the surface temperature of the concrete pavement was investigated. Table 2 and Figure 2 shows the results of measuring the temperature of the surface by installing a temperature sensor in the upper portion.

As described above, according to the present invention, the repair capacity is increased while the deterioration of the bending strength is hardly generated, and the water is released from the packaging material so that the surface temperature of the concrete pavement is lowered by about 20 to 25 ° C. than the existing concrete. This can greatly reduce the heat island effect and increase the persistence of the heat island effect.

Claims (3)

 In the water-retaining concrete composition consisting of a water-repellent additive consisting of lightweight foamed concrete powder, pottery, waste vortex or zeolite, absorbent polymer, and water-soluble polymer in cement and particle size aggregates, Each component is 0.001 parts by weight to 5 parts by weight of at least one absorbent polymer selected from polyacrylates and derivatives thereof, polyethylene oxide derivatives and absorbent polyurethanes based on 100 parts by weight of cement, and 0.01 parts by weight of water-soluble polymer. 10 parts by weight, containing 3 to 15 parts by weight of the bottom ash as a water-retaining additive, A wet expansion retardant adsorbed onto the surface of the absorbent polymer to inhibit the expansion of the absorbent polymer by reacting with water, and includes 0.001 to 5 parts by weight of dextrin, glycerin or a mixture thereof based on 100 parts by weight of the absorbent polymer. A water-conservative concrete composition, characterized in that. delete delete

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