KR102368964B1 - Powder type waterproof and anticorrosive concrete admixture and high durability anticorrosive concrete composition using the same - Google Patents

Abstract

The present invention relates to a concrete powder-type admixture having waterproof and anti-rust properties and a concrete mixing composition and a cement binder including the same and, more specifically, to a concrete powder-type admixture including 35 to 50 parts by weight of an alkali metal salt-based rust inhibitor, 20 to 30 parts by weight of pozzolan, 1.5 to 2.5 parts by weight of a re-emulsifying powder resin containing a styrene-acrylic copolymer, 10 to 25 parts by weight of a higher fatty acid-based metal salt, and 5 to 15 parts by weight of a lignin sulfonate-based superplasticizer to provide high strength and high durability to a concrete composition or cement binder while providing excellent waterproof and anti-rust properties, and an anticorrosive concrete mixing composition and cement binder including the same.

Description

Concrete powder-type admixture having waterproof and rust-preventive properties and high-durability concrete mixing composition using the same

The present invention relates to a concrete powder-type admixture having waterproof and rust-preventive properties, a highly durable anticorrosive concrete mixing composition comprising the same, and a cement binder.

In general, concrete is manufactured by mixing cement, water, fine aggregate, coarse aggregate, and mixed materials as the basis. Concrete structures are eroded or weakened by acids and chlorine depending on the environment in which they are used, and when water diffuses or penetrates inside and outside, corrosion of the internal rebar and the elution of calcium hydroxide occur, which adversely affects durability. In other words, factors that reduce the durability of concrete include acid, salt, neutralization, and freezing damage, which generally penetrate into the concrete structure through water as a medium. Therefore, suppression of water intrusion is an important problem in concrete structures, and in order to secure and use safety up to the expected lifespan, it is required to perform waterproofing and anticorrosive treatment.

Conventionally, a waterproof/corrosive treatment has been mainly performed to form a film on the surface of a concrete structure using a sheet or a coating material. Membrane-based waterproofing is being performed to form a film on the concrete surface of SOC-related facilities such as railways, roads, ports, and water and sewage systems. Periodic maintenance is required due to the durability limit of concrete, and since concrete is a water-soluble structure, when a defect occurs, it spreads to the front end and is mostly performed full-scale repair rather than local repair. there was

SOC-related offshore structures in the coastal areas are also designed with high strength, and as a countermeasure against salt damage, the thickness of concrete is increased, and rust-preventive paint is applied to the area in contact with the sea level to prevent corrosion of rebars. is difficult to expect.

On the other hand, in order to improve the physical properties and performance of concrete and to provide various functions suitable for special purposes, the case of adding functional admixtures during concrete mixing is increasing recently. As such an admixture, blast furnace slag, fly ash, silica fume, etc., which are pozzolanic materials, are used.

KR 100473730 B1 KR 101816149 B1

An object of the present invention is to provide a concrete powder-type admixture for imparting waterproof and rust prevention properties to a concrete composition.

In addition, it is another object to provide a high-durability cement binder and a high-durability concrete composition that does not require a separate waterproofing treatment by including a concrete powder-type admixture having waterproof and rust-proof properties.

According to an aspect of the present invention, 35 to 50 parts by weight of an alkali metal salt-based rust inhibitor, 20 to 30 parts by weight of pozzolan, 1.5 to 2.5 parts by weight of a re-emulsifiable powder resin comprising a styrene-acrylic copolymer, 10 to 10 parts by weight of a higher fatty acid-based metal salt 25 parts by weight and 5 to 15 parts by weight of a lignin sulfonate-based superplasticizer, a concrete waterproofing and rust-preventing admixture is provided.

According to another aspect of the present invention, 0.1 to 1 parts by weight of the concrete waterproofing and rust prevention admixture, 0.1 to 0.5 parts by weight of a high performance water reducing agent or high performance AE water reducing agent, 15 to 25 parts by weight of a cement binder, 25 to 40 parts by weight of fine aggregate, and 40 parts by weight of coarse aggregate to 55 parts by weight, an anticorrosive concrete compounding composition is provided.

In addition, the cement binder may include 45 to 70 parts by weight of Portland cement, 20 to 35 parts by weight of blast furnace slag, and 5 to 20 parts by weight of fly ash based on 100 parts by weight of the cement binder.

In addition, the anticorrosive concrete mixing composition is manufactured under the conditions of a maximum coarse aggregate size of 25 mm, a water/binder ratio (W/B) of 40% or less, a standard air amount of 6.5±1.5%, and a slump of 150±25 mm, and a minimum compressive strength of 35 MPa and a maximum chlorine ion penetration resistance of 1,000 coulombs.

According to another aspect of the present invention, 1 to 5 parts by weight of the concrete waterproofing and rust preventing admixture, 45 to 70 parts by weight of Portland cement, 20 to 35 parts by weight of blast furnace slag and 5 to 20 parts by weight of fly ash, and water/bonding A cement binder is provided, which is produced with a ash ratio (W/B) of 40% or less.

The admixture according to one aspect of the present invention may be applied to a concrete composition or cement binder to provide excellent waterproofing and rustproofing properties.

Since the concrete composition according to another aspect of the present invention has excellent waterproofing and rustproofing properties, it is suitable for application to deep underground structures subjected to water pressure without a separate membrane-based waterproofing treatment. Specifically, unlike conventional concrete, concrete itself has waterproofness and rust prevention properties to prevent corrosion of reinforcing bars due to chloride, so it can exhibit excellent durability even under harsh environmental conditions.

In addition, when the concrete composition according to an aspect of the present invention is applied instead of applying the conventional membrane-based waterproofing treatment to SOC-related facilities, a structure having excellent stability, durability, functionality and comfort can be formed. Through this, it can be applied as an effective alternative to the depletion of construction resources by increasing the durability of the structure, and can be used as a sustainable and eco-friendly construction material. In addition, it can satisfy the durability quality standards suitable for application to the monolithic cement concrete bridge deck, and can show the effect of improving the service life, shortening the period, reducing the construction cost, and reducing the LCC (life cycle cost) cost.

In addition, since it has excellent compressive strength, chloride ion penetration resistance, abrasion resistance, freeze-thaw resistance, surface peeling resistance, crack generation resistance and drying shrinkage, it can be applied as an excellent concrete structure with high durability.

The cement binder according to another aspect of the present invention may exhibit excellent rust resistance, waterproofness and durability.

The present invention relates to a concrete powder-type admixture having waterproofing and rustproofing properties, a manufacturing method thereof, a waterproofing and rustproofing cement binder and a high-durability anticorrosive concrete composition comprising the same.

Hereinafter, the present invention will be described in more detail. Technical and scientific terms used in this specification may be interpreted as meanings commonly understood by those of ordinary skill in the art to which this invention belongs.

According to one aspect of the present invention, there is provided a concrete powder-type waterproof and rust-proof admixture. The admixture is intended to provide waterproof and rust-preventive properties to concrete, and may be in the form of a powder. The admixture may include an alkali metal salt-based rust preventive agent, pozzolan, a re-emulsifying powder resin, a higher fatty acid-based metal salt, and a high-performance water reducing agent.

The admixture includes an alkali metal salt-based rust inhibitor. The alkali metal salt-based rust preventive agent may be a powder-type rust preventive agent for preventing corrosion of steel materials in which an organic active agent for strengthening the reinforcing bar passivation film deposition is added to an alkali metal salt containing calcium hydroxide or calcium nitrate. In general, anode-type inorganic salt-based calcium nitrite or sodium nitrite is mainly used as a rust preventive agent, but the admixture according to one aspect of the present invention blocks electrochemical corrosion reaction by including the alkali metal salt-based compound as a rust preventive agent, thereby exhibiting a better rust prevention effect. can Specifically, by adding the function of the water-soluble calcium-based positive and negative electrode composite corrosion inhibitor of the alkali metal salt containing calcium hydroxide or calcium nitrate to passivate the surface of the reinforcing bar, and by adding the function of the organic active agent to inhibit the negative electrode and the adsorption type corrosion inhibitor By forming a diffusion barrier layer and a stable water-soluble chelate film with metal ions, it is possible to compensate for the cause of the deterioration of the rust prevention performance of the anode inhibitor due to the uncertain dispersibility of the powder and to exhibit more robust rust prevention properties for rebar. The alkali metal salt-based rust preventive agent may be included in an amount of 35 to 50 parts by weight, preferably, 36 to 50 parts by weight of 100 parts by weight of the admixture. If the content of the alkali metal salt-based rust preventive agent is less than 35 parts by weight, it is difficult to sufficiently exhibit the desired anti-rust effect, and if it exceeds 50 parts by weight, the cost increases, and when the content of other components is reduced and applied to concrete, other physical properties except for rust resistance are lowered problems may arise.

The admixture includes pozzolan. Pozzolan is a fine powder with amorphous silica with high activity. It has no hydraulic properties by itself, but when combined with cement, it reacts with Ca(OH) ₂ generated during the hydration reaction of cement and is stable insoluble. Calcium silicate hydrate (CaO-SiO ₂ -nH ₂ O) is produced. Silica having pozzolanic activity may be selected from those generally used in the art, for example, silicate clay, volcanic ash, diatomaceous earth, tuff, perlite, fly ash, blast furnace slag, silica fume, calcined clay and calcined shale. At least one selected from may be used, but is not limited thereto.

In the admixture of a preferred embodiment of the present invention, the pozzolan is preferably micro silica-fume having excellent chemical durability. The micro silica fume may have an average particle size of 0.1 to 0.2 μm and a specific surface area of 180,000 to 200,000 cm 2 /g, but is not limited thereto. The pozzolan may be included in an amount of 20 to 30 parts by weight, preferably 22 to 30 parts by weight, in 100 parts by weight of the admixture. If the pozzolan content is less than 20 parts by weight, it is difficult to sufficiently exhibit the effect of the addition, and if it is more than 30 parts by weight, a problem of lowering the strength of concrete may occur when added to concrete.

The admixture includes a re-emulsifiable powder resin. As a powder resin included in conventional admixtures, Ethylene Vinyl Acetate (EVA), Styrene Butadiene Rubber (SBR) or acrylate copolymer were mainly used, but these have excellent adhesion and abrasion resistance, but are waterproof. And there is a limit to improving durability. Re-emulsifying powder resin included in the admixture according to an aspect of the present invention by replacing such a powder resin is stably dispersed when added to water, and can form an irreversible polymer film that does not dissolve in water after drying or curing. there are advantages to When concrete is manufactured, it is uniformly dispersed in the cement paste to form a cement gel by cement hydration, and at the same time, polymer particles are deposited on the surface of the cement gel to form an insoluble film or fill the capillary and gel voids, thereby shrinking the cement. It can prevent cracks caused by such factors and at the same time act as a binder in the drying or curing process of cement, thereby increasing adhesion with organic and inorganic substrates, and abrasion resistance and flexibility of cement mortar.

As the re-emulsifiable powder resin, for example, vinyl acetate homopolymers, vinyl acetate/ethylene copolymers, styrene-acrylic copolymers, and ethylene At least one selected from the group including /vinyl laurate/vinyl chloride triple polymerization polymer (Ethylene/vinyl laurate/vinyl chloride Terpolymer) may be used, but is not limited thereto. Preferably, in terms of maximizing the performance of the prepared admixture, the re-emulsifying powder resin may include a styrene-acrylic copolymer. The re-emulsifying powder resin may be included in an amount of 1.5 to 2.5 parts by weight in 100 parts by weight of the admixture. When the content of the re-emulsifiable powder resin is within the above-mentioned range, the prepared admixture may exhibit the desired excellent waterproofness.

The admixture includes a higher fatty acid-based metal salt. The higher fatty acid-based metal salt reacts with soluble calcium hydroxide (Ca(OH) ₂ ) generated according to the hydration reaction of cement to produce high water-repellent high-fatty acid calcium in which a fatty acid group is bound to a hydroxyl group. It works by reducing the absorption of moisture.

As the higher fatty acid-based metal salt, for example, at least one selected from the group consisting of zinc stearate, calcium stearate, ammonium stearate, calcium oleate, aluminum oleate and butyl stearate may be used, but is not limited thereto. The higher fatty acid-based metal salt may be included in an amount of 10 to 25 parts by weight, preferably 14 to 22 parts by weight, in 100 parts by weight of the admixture. When the content of the higher fatty acid-based metal salt is less than 10 parts by weight, it is difficult to show the waterproofing effect due to the higher fatty acid. There may be a problem of lowering the

The admixture may include a high-performance water reducing agent. When a melamine-based or naphthalene-based water reducing agent is included in the anticorrosive concrete composition, the slump of the concrete composition is remarkably reduced, and thus workability may be deteriorated. Accordingly, the admixture according to one aspect of the present invention may include a lignin sulphonate-based high-performance water reducing agent capable of improving the dispersibility of cement while having excellent compatibility with all chemical admixtures. The lignin sulfonate-based superplasticizer may be included in an amount of 5 to 15 parts by weight, preferably 9 to 13 parts by weight, in 100 parts by weight of the admixture. When the content of the lignin sulfonate-based superplasticizer is within the above range, good dispersibility and slump can be obtained.

An admixture according to an aspect of the present invention can be prepared by mixing or blending the above-mentioned components. The manufacturing of the admixture may be performed according to the production process standard by determining the mixing ratio of the raw materials, the input order, and the mixing time. According to the method for manufacturing an admixture according to a preferred embodiment of the present invention, after the production process standard is set according to the mixing ratio of the raw materials, a higher fatty acid-based metal salt, silica fume, lignin sulfonate-based high-performance water reducing agent, re-emulsifying powder resin in a mixer and the alkali metal salt-based powder-type rust preventive agent is added in order. After vacuum mixing for more than 5 minutes by adjusting the speed of the zero-gravity mixer, it passes through a roll crusher and sorter, measures the weight within the tolerance range, and produces it in the packaging area assigned with the LOT number, and the product is produced on a wooden pallet can be stored in the

According to another aspect of the present invention, there is provided an anticorrosive concrete composition comprising a concrete waterproofing and rust preventing admixture according to an aspect of the present invention. Here, anticorrosive concrete is functional concrete that is distinguished from general concrete, and refers to functional concrete capable of preventing corrosion of both concrete and reinforcing bars by having all of waterproofness, rust prevention and durability. The anticorrosive concrete composition may include an admixture, cement binder, aggregate and water reducing agent according to an aspect of the present invention.

The anticorrosive concrete composition includes a concrete waterproofing and rust-preventing admixture according to an aspect of the present invention. Hereinafter, the concrete waterproofing and rust preventing admixture according to an aspect of the present invention will be described as a PPS (pozzolan polymer stearate) admixture. The anticorrosive concrete composition may exhibit excellent rust prevention and waterproofing properties by including the PPS admixture. In 100 parts by weight of the anticorrosive concrete composition, the content of the PPS admixture may be included in 0.1 to 1 parts by weight, preferably 0.2 to 0.8 parts by weight. If the content of the admixture is less than 0.1 part by weight, it is difficult to exhibit the effect of improving waterproofing and rust prevention due to the addition, and if it exceeds 1 part by weight, there may be problems in that the manufacturing cost increases and the strength of concrete is lowered.

The anticorrosive concrete composition includes a cement binder. The cement binder includes Portland cement and pozzolan. Here, the pozzolan included in the cement binder preferably includes at least one selected from the group consisting of blast furnace slag and fly ash.

Blast furnace slag with pozzolanic activity is a by-product generated when pig iron is manufactured in a blast furnace, and can be obtained by rapidly cooling the blast furnace slag in a molten state by adding a large amount of pressurized water. Generally speaking, blast furnace slag means crushed blast furnace slag, and ground granulated blast furnace slag means that crushed blast furnace slag is dried and pulverized and an alkali stimulant is added as necessary. Blast furnace slag is a useful latent hydraulic material. The hydrate produced by the reaction of blast furnace slag and calcium hydroxide is chemically more stable and dense than the hydrate produced by hydration of cement alone, so it can form a denser hardened body structure. Compared to that, it has the advantage of reducing the amount of cement due to its high activity. In addition, the resistance to carbon dioxide penetration increases due to the densification of the concrete work structure, which can improve the resistance to neutralization and the salt damage and abrasion resistance of concrete. suitable for application.

Fly ash uses pulverized coal as fuel in combustion boilers such as thermal power plants and collects coal ash contained in the waste gas discharged from the high-temperature combustion process at about 1400° C. by a dust collector. The main components are silica and alumina. It may have a specific surface area of 3000 to 4500 cm 2 /g, a specific gravity of 1.9 to 2.3, and a particle size of 1 to 150 μm.

In terms of satisfying the durability quality standards of high-durability corrosion-resistant concrete, the maximum binder ratio of concrete in the design of the corrosion-resistant concrete mix is 25% or less of fly ash, 50% or less of fine blast furnace slag powder, 10% or less of silica fume, and fly ash or other It is preferable that the sum of pozzolan and silica fume be 35% or less, and the sum of fly ash or other pozzolans, blast furnace slag fine powder and silica fume is 50% or less. Here, % means the weight% of each component with respect to 100% by weight of the binder.

In 100 parts by weight of the anticorrosive concrete composition, the content of the cement binder when mixing concrete may be 15 to 25 parts by weight, preferably 17 to 24.6 parts by weight. If the content of the cement binder is less than 15 parts by weight or more than 25 parts by weight, there may be a problem in that the concrete strength is lowered.

The anticorrosive concrete composition includes fine aggregates and coarse aggregates as aggregates. The aggregate may be selected and used according to the specifications for concrete, for example, fine aggregate that passes through a 5mm sieve, and coarse aggregate that does not pass through a sieve may be used. At this time, it is preferable that the coarse aggregate does not exceed the maximum dimension of 25 mm.

Based on 100 parts by weight of the anticorrosive concrete composition, the fine aggregate may be included in 25 to 40 parts by weight, preferably 26 to 36 parts by weight. In addition, the coarse aggregate may be included in an amount of 40 to 55 parts by weight. When the content of the fine aggregate and the coarse aggregate are each included in the above-described content range, the produced concrete may exhibit excellent strength.

The anticorrosive concrete composition includes a high-performance water reducing agent or a high-performance AE water reducing agent. 0.1 to 0.5 parts by weight of the high performance water reducing agent or high performance AE water reducing agent, preferably 0.1 to 0.3 parts by weight, may be included in 100 parts by weight of the anticorrosive concrete composition. When the content of the high-performance water reducing agent or the high-performance AE water reducing agent is included within the above-described content range, it is possible to lower the water/binder ratio of concrete and exhibit appropriate fluidity and strength enhancing effects.

If necessary, the anticorrosive concrete composition may further include other chemical admixtures in order to improve the performance while reducing the manufacturing cost of the anticorrosive concrete. The other chemical admixture may be, for example, at least one selected from the group consisting of an air entraining agent, a water reducing agent, and a high performance water reducing agent, but is not limited thereto.

Anticorrosive concrete composition according to another aspect of the present invention can be prepared by mixing or blending with the above-mentioned components and contents. It is desirable to increase the concrete mixing time at the time of mixing by 2 to 3 times the normal concrete mixing time, the maximum coarse aggregate size of 25 mm, the water/binder ratio (W/B) 40% or less, the standard air volume 6.5 It is good to mix conditions of ±1.5% and slump 150±25. The concrete composition according to another aspect of the present invention can exhibit excellent rust prevention, waterproofness and durability by being blended with the same components and contents as described above.

Substances such as ions, moisture, and carbon dioxide that penetrate into concrete cause corrosion of reinforcing bars or expansion of concrete through chemical reaction, which significantly affects the durability of concrete. Accurately evaluate the resistance of concrete to penetration of these substances This is very important in determining durability. Durability is difficult to satisfy simply by expressing high strength, and waterproofness is also related to the compactness of the tissue structure in the concrete, so there is a connection with penetration resistance. It is necessary to satisfy the ion penetration resistance.

In the case of chloride ion penetration resistance, in North Europe, NT BUILD 492 and in the United States are evaluated by the chlorine ion diffusion coefficient by ASTM C 1202 method, but in Korea, it is generally tested according to KS F 2711, a test method for chlorine ion penetration resistance of concrete based on electrical conductivity. do. This test method evaluates the penetration resistance of concrete by the amount of coulombs that force chlorine ions to pass through the concrete by applying a potential difference. Permeability is very low, and if it is less than 100, the permeability is evaluated as negligible.

The anticorrosive concrete composition according to another aspect of the present invention may have a compressive strength of 35 MPa or more and a chloride ion penetration resistance of 1,000 coulombs or less. When the compressive strength of the anticorrosive concrete composition is 35 MPa or more, it can be applied as a safe high-strength concrete composition because it satisfies the minimum compressive strength criterion of reinforced concrete of the road construction standard specification. In addition, if the chloride ion penetration resistance of the anticorrosive concrete composition is 1,000 coulombs or less, the national construction standards standard specification, durability quality standards for cement concrete pavement construction, and expressway construction specialized specifications integrated cement concrete bridge surface pavement without performing separate waterproofing surface treatment Since it meets the durability quality standards, it can be applied as an excellent functional anticorrosive concrete composition.

According to another aspect of the present invention, there is provided a cement binder of high durability comprising the admixture according to an aspect of the present invention.

The cement binder may include PPS admixture, Portland cement, blast furnace slag and fly ash according to an aspect of the present invention.

The cement binder includes a PPS admixture according to an aspect of the present invention. 1 to 5 parts by weight of the PPS admixture, preferably 1 to 4 parts by weight, may be mixed in 100 parts by weight of the cement binder. When the content of the admixture is included within the above range, excellent rust prevention, waterproofing and durability can be imparted.

The cement binder includes Portland cement. 100 parts by weight of the cement binder, 45 to 70 parts by weight of the Portland cement, preferably 49 to 67 parts by weight may be included. When the Portland cement content is included within the above range, excellent durability and strength may be exhibited.

The cement binder includes blast furnace slag. In 100 parts by weight of the cement binder, 20 to 35 parts by weight of the blast furnace slag, preferably 22 to 34 parts by weight, may be included. When the blast furnace slag content is within the above-mentioned range, excellent durability and strength may be exhibited.

The cement binder may include fly ash. 100 parts by weight of the cement binder, 5 to 20 parts by weight of the fly ash, preferably 9 to 17 parts by weight may be included. When the fly ash content is included within the above range, excellent durability and strength may be exhibited.

If necessary, the fly ash may be substituted with other pozzolans other than fly ash. As other alternative pozzolans, for example, at least one selected from the group consisting of silicate clay, volcanic ash, diatomaceous earth, tuff, perlite, silica fume, calcined clay and calcined shale may be used, but is not limited thereto.

A cement binder according to another aspect of the present invention may be prepared by mixing or blending the above-described components and contents. It is preferable that the water/binding material ratio (W/B) is 40% or less during mixing. Cement binder according to another aspect of the present invention By being blended with the same components and contents as described above, excellent rust prevention, waterproofing and high durability properties can be exhibited.

Hereinafter, preferred embodiments are presented to help the understanding of the present invention, but these examples are merely illustrative of the present invention and do not limit the appended claims, and are within the scope and spirit of the present invention. It is obvious to those skilled in the art that various changes and modifications are possible, and it is natural that such variations and modifications fall within the scope of the appended claims.

Example

<Production of waterproof and rust-preventive powder-type admixture>

After the production process standard is accurately set according to the mixing ratio of the raw materials, zinc stearate, microsilica fume, lignin sulfonate-based high-performance water reducing agent, styrene-acrylic copolymer-containing re-emulsifying powder resin and calcium hydroxide at the mixing ratio of Table 1 in the mixer And calcium nitrate as a main component and an organic active agent was added to the steel corrosion-preventing powder-type rust inhibitor added in order. PPS admixture was prepared by vacuum mixing at 85RPM at the speed of the zero-gravity mixer for more than 5 minutes, then passing through the roll crusher and sorter, and then weighing it to a weight within the tolerance range. In Table 1 below, each numerical value means a value in parts by weight.

division stearic acid
zinc Micro
Silica fume high performance water reducing agent re-emulsification
powdered resin rust inhibitor Preparation Example 1 22 23 13 2 40 Preparation Example 2 20 30 15 3 32 Preparation 3 30 11 5 One 53 Preparation 4 17 26.5 9 2.5 45

For the admixture performance test for each manufactured example, 160 parts by weight of water, 262 parts by weight of cement, 122 parts by weight of blast furnace slag, 52 parts by weight of fly ash, 677 parts by weight of fine aggregate, 1027 parts by weight of coarse aggregate with a maximum size of 2.5 mm or less, high performance AE After preparing an anticorrosive concrete composition by mixing with 2.62 parts by weight of water reducing agent and 15.2 parts by weight of admixture for each preparation example, waterproofness, rust prevention and chloride ion penetration resistance were confirmed, and the results are shown in Table 2 below. Details of the performance test for each item will be described later in Examples related to the formulation design.

Item age
(Work) unit Test result Preparation Example 1 Preparation Example 2 Preparation 3 Preparation 4 waterproof water absorption coefficient ratio 28 - 0.56 0.45 0.80 0.59 permeability 28 - 0.62 0.52 0.85 0.65 rust prevention attendance rate - % 61.3 35.5 65.2 63.2 Chloride ion penetration resistance 56 Coulomb 975 1242 1327 988

Referring to Table 2, it was found that the waterproof, rust-preventive and chloride ion penetration resistance of Preparation Examples 1 and 4 corresponding to the composition of a preferred embodiment of the present invention were all excellent. Preparation Example 2 did not have sufficient antirust property and the chlorine ion penetration resistance also exceeded 1000 Coulombs, and Preparation Example 3 showed that the waterproofness was lowered and the chloride ion penetration resistance exceeded 1000 Coulombs, and the high durability concrete performance for the purpose of the present invention was obtained. appeared not to be satisfied.

<Waterproof, rust prevention and durability performance test>

A test was performed to confirm waterproofness, rust prevention and durability through the formulation design of the anticorrosive concrete mixing composition containing the PPS admixture of Preparation Example 1. After mixing concrete by providing a concrete mixing table according to the Examples and Comparative Examples in Table 3 below, waterproof, rust-preventing and durability tests were requested to SGS Korea Construction Testing & Research Institute and conducted according to the test regulations for each item. The results are shown in Table 4 below. In Table 3 below, W/B means water/binder ratio, S/a means fine aggregate ratio, W of unit material is water, C of binder is cement, Slag is blast furnace slag, F/ A stands for fly ash, S stands for fine aggregate, and G stands for coarse aggregate.

division W/B
(%) S/a
(%) Unit material consumption (kg/㎥) W Binder S G high performance
AE water reducer PPS
admixture C Slag F/A Example 36.7 40.0 160 262 122 52 677 1027 2.62 15.2 Comparative Example 1 36.0 38.0 168 279 139 47 627 1034 2.80 - Comparative Example 2 38.0 40.0 157 253 118 51 685 1048 2.50 4.0 Comparative Example 3 38.0 40.0 157 248 116 50 679 1026 2.58 20.7

The waterproof performance of the manufactured anticorrosive concrete was evaluated by confirming the water absorption coefficient ratio and water permeability resistance. For the waterproof performance of concrete concrete, water absorption resistance and water permeability resistance were tested according to KS F4926 for the mortar remaining after the coarse aggregate was separated by sieving unhardened concrete through a 5mm sieve. The water absorption coefficient of the Example measured according to KS F4926 was 0.0045 kg/m ² .h ^0.5 , and the water absorption coefficient of Comparative Example 1 was 0.008 kg/m ² .h ^0.5 , and the water absorption coefficient for each composition in Table 2 below. Ratio represents the relative value of each composition based on the water absorption coefficient value of Comparative Example 1. The water permeability of the Example measured according to the KS F 4926 test method was 2.2 g, and it was found that the water permeation amount of Comparative Example 1 was reduced than 3.55 g.

The rust prevention properties are related to the rebar corrosion prevention function, so the rust prevention performance of the manufactured anticorrosive concrete was confirmed through the reinforcement corrosion promotion test in concrete. 6.6 kg of NaCl was dissolved in the mixing water in advance so that the salt (Cl ^- ) content in the concrete was 4.0 kg/m3 and added to the mixing water, and the rust prevention rate test was performed using the accelerated steam curing method according to KS F 2561. Confirmed. The corrosion area of the measured Example was 1.326 mm ² , and the corrosion area of Comparative Example 1 was 3.426 mm ² . Based on the example, the rust prevention rate is [1-(corrosion area of Example / Corrosion area of Comparative Example 1)] x 100 to obtain a relative rust prevention rate value, and Comparative Examples 2 and 3 also compare each instead of the corrosion area of Examples The corrosion area of the example was introduced and the value was obtained in the same way and shown in Table 2 below.

The durability of the manufactured concrete is verified by performing tests according to the national construction standards standard specifications, the durability performance quality standards of cement concrete pavement construction, and the quality standards of the integrated (exposed) cement concrete surface pavement durability standards in the specialized expressway construction specifications. did Compressive strength according to KS F 2405, chloride ion penetration resistance according to KS F 2711, freeze-thaw resistance according to KS F 2456, surface peel resistance according to SS 13 72 44 (Method A), crack resistance according to AASHTO PP 34 99, Abrasion resistance according to ASTM C 779-12 (Type B) and drying shrinkage test according to KS F 2424 were performed. In the case of Examples, the slump 155mm according to KS F2402, the amount of air according to KS F 2421 is 5.6%, the compressive strength at 7 days of age is 38.9 MPa, the compressive strength at 56 days of age is 54.7 MPa, and the surface according to SS 13 72 44 As a result of the peel resistance test, m ₅₆ : 0.30 kg/m ² , m ₅₆ /m ₂₈ : 1.74 showed excellent physical properties. In the case of Comparative Example 1, the slump 150mm according to KS F2402, the amount of air according to KS F 2421 was 5.1%, the compressive strength at the age of 7 days was 38.7 MPa, the compressive strength at the age of 56 days was 52.4 MPa, and the SS 13 72 44 was As a result of the surface peeling resistance test according to m ₅₆ : 0.35 kg/m ² , m ₅₆ /m ₂₈ : 1.85.

Item age
(Work) unit Test result Example Comparative Example 1 Comparative Example 2 Comparative Example 3 waterproof water absorption coefficient ratio 28 - 0.56 1.0 0.84 0.51 permeability 28 - 0.62 1.0 0.91 0.55 rust prevention attendance rate - % 61.3 0 45.2 65.8 durability compressive strength 28 MPa 47.7 46.9 34.2 33.6 Chlorine ion penetration
resistance 56 Coulomb 975 1235 1210 1120 Freeze-thaw resistance 56 % 84.2 83.5 82.8 83.7 Surface peel resistance 56 - Great Great Great Great cracking resistance 56 - no cracks no cracks no cracks no cracks wear resistance 56 mm 0.36 0.41 0.52 0.45 drying shrinkage 56 % -0.0264 -0.0289 -0.0412 -0.0325

Concrete mixing conditions consisted of a maximum coarse aggregate size of 25mm, a water/binding material ratio (W/B) of 40% or less, a standard air volume of 6.5±1.5%, and a slump of 150±25mm. Compressive strength (f=28) It was confirmed as a compounding composition that satisfies the chlorine ion penetration resistance of 1,000 Coulombs or less in the mixing standard of 35 MPa or more.

By comparing Examples and Comparative Example 1 with reference to Table 4, in the case of the concrete mixture composition according to the present invention, the concrete powder-type PPS admixture was added in an appropriate amount and the waterproof performance according to the water repellency component and watertightness of the concrete itself. is improved, and at the same time, due to the synergistic effect of rust prevention due to the blocking of electrochemical corrosion reaction due to the addition of the alkali metal salt-based powder-type rust preventive agent, compared to the composition of Comparative Example 1 which does not contain the concrete powder-type PPS admixture, waterproof, rust-preventive and chloride ion penetration It can be seen that the resistance exhibits a remarkably improved effect.

In the case of Comparative Example 2, it was found that the improvement in antirust property was lower than that of the Example by including the concrete powder-type PPS admixture in an appropriate amount less than the appropriate addition content, and the compressive strength of 28 days of age was also not satisfactory at 35 MPa. In addition, it can be seen that the result in the chlorine ion penetration resistance item is also significantly lower than that of the Example.

In the case of Comparative Example 3, the manufacturing cost was increased by including the concrete powder-type PPS admixture in an excessive amount exceeding the appropriate added content, but the compressive strength was rather lowered, and the chloride ion penetration resistance, which is the most important in the high-durability concrete mixture composition, exceeded 1,000 Coulombs. appeared to be

Referring to the test results, when the PPS admixture according to an embodiment of the present invention is included in an appropriate amount, the concrete mixture composition has improved waterproofness, rust prevention and durability, while satisfying excellent strength properties. The concrete composition including the PPS admixture according to an embodiment of the present invention is suitable to be applied as a high-durability concrete structure having waterproof and rust-proof properties.

Claims (5)

35 to 50 parts by weight of an alkali metal salt-based rust inhibitor, 20 to 30 parts by weight of pozzolan, 1.5 to 2.5 parts by weight of a re-emulsifiable powder resin containing a styrene-acrylic copolymer, 10 to 25 parts by weight of a higher fatty acid-based metal salt, and a lignin sulfonate-based salt 5 to 15 parts by weight of a superplasticizer,
The alkali metal salt-based rust preventive agent is a powder-type rust preventive agent for preventing corrosion of steel materials in which an organic active agent is added to an alkali metal salt containing calcium hydroxide or calcium nitrate,
Admixture for anticorrosive concrete.
0.1 to 1 part by weight of the admixture of claim 1, 0.1 to 0.5 parts by weight of a high performance water reducing agent or high performance AE water reducing agent, 15 to 25 parts by weight of cement binder, 25 to 40 parts by weight of fine aggregate, and 40 to 55 parts by weight of coarse aggregate,
An anticorrosive concrete mix composition with a minimum compressive strength of 35 MPa and a maximum chloride ion penetration resistance of 1,000 coulombs.
The method according to claim 2, wherein the cement binder comprises 45 to 70 parts by weight of Portland cement, 20 to 35 parts by weight of blast furnace slag, and 5 to 20 parts by weight of fly ash based on 100 parts by weight of the cement binder.
The method according to claim 2, Coarse aggregate maximum size 25㎜, water / binder ratio (W / B) 40% or less, standard air amount of 6.5±1.5%, and slump 150±25mm The composition is prepared by mixing, anticorrosive concrete mixing composition.
1 to 5 parts by weight of the admixture of claim 1, 45 to 70 parts by weight of Portland cement, 20 to 35 parts by weight of blast furnace slag, and 5 to 20 parts by weight of fly ash, and prepared in a water/binder ratio (W/B) of 40% or less Cement binder for anticorrosive concrete.