KR20170113737A - Vinyl acetate-ethylene polymer modified concrete compostion and Method for pavement using the same - Google Patents

Abstract

The present invention relates to a VAE modified cement composition.
The VAE modified cement composition according to the present invention is a polymer modified concrete composition comprising a mixture of cement, aggregate, polymer emulsion and water, wherein the polymer emulsion is characterized by comprising a vinyl acetate-ethylene (VAE) copolymer.
The VAE modified cement composition according to the present invention can be applied to a cement composition itself, a concrete composition including both coarse aggregate and fine aggregate, and a mortar composition including only fine aggregate.

Description

[0001] The present invention relates to a VAE modified cement composition,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cement composition, and more particularly, to a polymer-modified cement used for packing a load intensive structure such as a bridge surface or a building roof.

A bridge is a collective term for high-priced structures that are designed to pass over the upper parts of streams, coasts, and roads. On the surface of the bridge, a bridge pavement layer is formed on the concrete bottom plate so that the vehicle can pass smoothly.

The pavement pavement layer is a part that directly transmits the traffic load. In addition to having strength and crack resistance suitable for repeated traffic loads, it is required to have waterproof performance because it is exposed to moisture such as rainwater. In particular, It is required to have a low chloride ion permeability in order to prevent the rebar from being corroded by penetration.

Conventionally, a conventional concrete pavement method or an ascon pavement method has been widely known as such a pavement pavement method. However, concrete pavement methods and cracks easily occur, and the flame resistance is poor. The asbestos packaging method has problems such as periodic repackaging by plastic deformation and surface deterioration.

In order to solve these problems, a polymer-modified concrete having a rubber-like polymer latex (SB-Latex) mixed with concrete has been developed.

 As shown in FIG. 1, when the latex is uniformly dispersed in the concrete, the water evaporates and a polymer film is formed between the cement particles to increase the adhesive strength and elasticity of the concrete. From the aspect of physical properties, there is an advantage that the adhesion strength and flexural strength of the concrete are increased, and the microvoids between the cements are filled with the latex to prevent diffusion of chlorine ions.

However, the existing SB-Latex uses styrene and butadiene, which are materials derived from petroleum, as main raw materials, so supply and demand are unstable depending on oil prices and there is a problem that price fluctuation is severe. Supply chain stability and price stability are very important factors in manufacturing management. Supply and demand should be stabilized and forecasts for the future can be made, and consumers can respond appropriately to demand.

It is an object of the present invention to solve the above-mentioned problems, and it is an object of the present invention to provide a method for improving the physical properties of concrete, which is capable of stable supply and demand and which is more economical than SB-Latex, Cement composition for use in the present invention.

In order to accomplish the above object, the VAE modified cement composition according to the present invention is a mixture of cement, aggregate, polymer emulsion and water, and the polymer emulsion is characterized by comprising a vinyl acetate-ethylene (VAE) copolymer have.

According to the present invention, the vinyl acetate-ethylene copolymer is preferably used by mixing a plurality of vinyl acetate-ethylene copolymers having different glass transition temperatures. In particular, the vinyl acetate-ethylene copolymer preferably has a glass transition temperature of less than 0 ° C in comparison with a subzero temperature and a glass transition temperature of 30 ° C or more in comparison with a high temperature.

In one embodiment of the present invention, the vinyl acetate-ethylene copolymer is mixed with three different glass transition temperatures, and the glass transition temperature of each of the three VAE copolymers is in the range of -50 to -20 ° C, 30 < 0 > C, and 30-60 < 0 > C.

According to the present invention, it is preferable to mix 5 to 20% by weight of cement, 67 to 90% by weight of aggregate, 1 to 6% by weight of water and 2 to 10% by weight of polymer emulsion.

In the mortar according to one embodiment of the present invention, it is preferable that the mortar is mixed in the range of 15 to 40 wt% of cement, 40 to 75 wt% of fine aggregate, 3 to 12 wt% of water and 4 to 10 wt% of polymer emulsion.

In one embodiment of the present invention, the polymer emulsion may be styrene butadiene rubber (SBR) or acrylic alone or in combination. When SBR or acryl is contained, the polymer emulsion may contain 50.1 to 99.9% by weight of the vinyl acetate- (Acrylic, or a mixture thereof) in the range of 0.1 to 49.9% by weight.

In one embodiment of the present invention, it is preferred that the polymer emulsion further comprises a polymer modifier, and the polymer modifier may be mixed in the range of 0.1 to 10 wt% in the entire polymer emulsion.

Particularly, as the polymer modifier, a polycarboxylic acid surfactant or an aqueous dispersion urethane surfactant and a nonionic surfactant are added singly or in combination.

More specifically, the polycarboxylic acid-based surfactant may be a copolymer of polyethylene glycol mono (meth) allyl ether and maleic anhydride, a copolymer of phenol mono (meth) allyl ether and (meth) acrylic acid, a polyalkylene glycol mono (Meth) acrylic acid copolymer, a methacrylic acid ester having a sulfonic acid group and a (meth) acrylic acid copolymer, and a polyglycerin (meth) acrylic acid ester copolymer.

The water-dispersible urethane-based surfactant may include a modified water-dispersed polyurethane copolymer.

In an embodiment of the present invention, the nonionic surfactant is selected from the group consisting of fatty acid diethanolamine compounds, amine oxides, nonylphenol ethylene oxide adducts, sorbitan esterified compounds, alkylpolyglycosides, fatty acid ethylene oxide adducts, polyethylene oxide (C12 to C22) ethylene oxide (EO) adducts (EO is 1 to 50), alkyl (C4 to C22), polypropylene oxide C20) amine oxides, alkyl (C4 to C20) phenol ethylene oxide adducts (EO is 1 to 50), sorbitan esterified compounds and ethylene oxide adducts (EO is 1 to 50), alkyl (C1 to C20) (Molecular weight: 100 to 100,000), polypropylene oxide (molecular weight: 100 to 100,000), poly (ethylene oxide) Polyethylene oxide and polypropylene jade Id there is at least one or two or more may be combined in the copolymer (molecular weight of 100 ~ 100,000), polyethyleneimine (molecular weight of 100 ~ 100,000), polyglycerol (molecular weight of 100 ~ 100,000).

The VAE modified cement composition according to the present invention is prepared by mixing a polymer emulsion containing vinyl acetate-ethylene as a main component into concrete, thereby realizing a physical property of concrete such as compressive strength, crack resistance and flame retardancy comparable to that of existing SB-Latex modified concrete . ≪ / RTI >

In particular, VAE copolymers are advantageous in that a cement composition ensures a constant performance irrespective of changes in temperature of the four seasons by using a mixture of different glass transition temperatures.

Above all, the modified cement composition according to the present invention not only remarkably improves the economical efficiency of concrete production but also stably supplies the modified cement as compared with the case of mixing the existing SB-Latex by mixing vinyl acetate-ethylene. .

The use of VAE as a main ingredient of modifiers has the advantage of being friendly to human and natural ecosystems.

Meanwhile, in the embodiment of the present invention, even when the polymer is mixed with concrete, the use of the polymer emulsion modifier that maintains the fluidity of the concrete for a certain period of time can be used not only in the case of using a mobile mixer car, And concrete pavement is possible.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view for explaining improvement of physical properties of a latex modified concrete. FIG.
2 is a schematic diagram showing the chemical structure of vinyl acetate-ethylene.
FIG. 3 is a table showing the mixing ratio of the samples for testing the physical properties of the VAE modified cement composition according to the invention.
FIG. 4 is a table showing the results of testing the physical properties of the VAE modified cement using the sample according to the table of FIG.
FIG. 5 is a table showing the compounding ratio of the sample for testing the physical properties of the VAE modified mortar according to the invention.
6 is a table showing the results of the physical properties of the VAE modified mortar using the sample according to the table of FIG.

The present invention relates to a polymer modified cement composition. Although the present invention is generally used mainly for the purpose of packaging the surfaces (bridges) of bridges, the subject of application of the concrete composition according to the present invention is not necessarily limited to bridges. That is to say, it can be widely used for bottom packing of a rooftop parking lot of a building, floor packing of an area where loads are applied repeatedly and repeatedly, such as a factory and a distribution center. Accordingly, the polymer modified cement composition according to the present invention should be determined by the matters described in the claims of the present invention regardless of the application.

Also, the VAE modified cement composition according to the present invention may be a VAE modified concrete composition or a VAE modified mortar composition according to an embodiment. That is, in the present invention, VAE polymer is added to cement, and it can be used as concrete by mixing with coarse aggregate such as gravel. In the case of pure cement including only fine aggregate such as sand except aggregate, Is used. Therefore, the VAE modified cement composition according to the present invention can be utilized as cement itself, mortar and concrete.

Hereinafter, the polymer modified concrete composition according to one embodiment of the present invention will be described in more detail.

The VAE modified concrete composition according to the present invention is generally made by mixing water with cement, sand, and gravel, which are materials of concrete. The concrete composition according to one embodiment of the present invention is mixed in the range of 5 to 20 wt% of cement, 67 to 90 wt% of aggregate, 1 to 6 wt% of water, and 2 to 10 wt% of polymer emulsion.

Then, the polymer emulsion is mixed so as to secure the compressive strength, crack resistance, and salt resistance required for the concrete used in the cross-pavement packaging. Also, in one embodiment of the present invention, the polymer emulsion modifier may be additionally mixed to improve the workability by securing the fluidity of the polymer-modified concrete.

However, in order to improve the physical properties of concrete, blast furnace slag cement, pozzolan cement, high flow cement, low heat cement, multicomponent mixed cement, salt resistant cement, expandable cement, (super) crude steel cement , (Second) cement, and cement powder may be used.

Also, instead of using the above-mentioned special cement as a finished product, a pozzolanic substance, a latent hydraulic material, an expandable material, a hardwood material, a filler and other mineral mixture and an organic admixture are used as a mixed material in general portland cement as a separate additive Concrete may also be produced. Gravel and sand are used as aggregate.

Above all, the present invention has a key feature in that vinyl acetate-ethylene (VAE) is used as the polymer emulsion. Referring to the structure of the vinyl acetate-ethylene of FIG. 2, the vinyl acetate-ethylene consists of a copolymer of vinyl acetate and ethylene. Vinyl acetate is polymerized at a ratio of 60 to 95%, and ethylene at a rate of 5 to 40%. VAE is used in some powder form, but it is generally used in liquid form. VAE is highly viscous and used in glass and plastic products to increase safety and durability. In the present invention, by using VAE, the viscosity of the concrete is improved to improve the crack resistance and strength of the concrete. In addition, when VAE is used in concrete, it has an advantage of being able to prevent the durability of winter snow removing agent from being weakened because the water tightness required in the pavement pavement and the penetration resistance against chlorine ion are increased.

The important point for the VAE resin to maintain the above function is the glass transition temperature. As the temperature is lowered below the glass transition temperature of the resin, the resin hardens and the elasticity deteriorates. When the temperature exceeds the glass transition temperature, the resin becomes too soft and loses its strength. Regardless of the change in temperature, the function of the VAE resin should be able to function properly.

In order to solve this problem, the present invention is characterized in that a plurality of VAEs having different glass transition temperatures are used. For example, a glass transition temperature of less than 0 ° C and a glass transition temperature of 0 ° C or higher may be used in combination. Three VAE resins having different glass transition temperatures may be further mixed and used. In case of using 3, it can be divided into 2 in the temperature range of the image.

Korea should take this into account when using VAE resin because of its distinctive four-seasons and temperature variations. That is, if the glass transition temperature (Tg) of the resin is high, it can be used in the summer, but in winter, the elasticity of the resin lowers, causing cracks and breakage. Conversely, resins with low glass transition temperatures can be used in winter, but they become too soft during summer and lose strength. Therefore, in the present invention, a plurality of VAE resins having different glass transition temperatures are used so that the cement composition can achieve a certain effect regardless of the seasonal change in consideration of annual temperature changes in the Republic of Korea. Therefore, in this embodiment, the glass transition temperature is in the range of -50 to -20 占 폚, -20 to 30 占 폚, and the glass transition temperature is in the range of 30 to 60 占 폚. More specifically, in this embodiment, three VAEs having a glass transition temperature of -40 ° C, 0 ° C, and 50 ° C, respectively, were mixed and used. The mixing ratios of the three can vary depending on the conditions.

As described above, the reason for using the VAE copolymer in the present invention is to enhance watertightness and flame retardancy. This is because the present invention is used for pavement packaging rather than general road pavement installed on the ground, and water can not enter the pavement layer in the pavement packaging. In addition, the snow removal agent is sprayed in the winter. When the chlorine-based snow remover melts in the water and flows into the inside of the packaging layer, the durability of the packaging layer is remarkably decreased due to the occurrence of salting. Unlike the present invention, VAE can be used for the purpose of adjusting the setting time and increasing the permeability, although the cement composition containing VAE as a modifier can be used for general road pavement. When the VAE is used for the adjustment of the coagulation time and the permeability, the proportion of the VAE in the mixed material is inevitably different from that of the present invention. As will be described later, in the present invention, at least 50% or more of VAE should be used in the entire mixed material, but only a small amount should be included in the case of adjusting the setting time and increasing the permeability. For example, in the addition ratio of VAE, the present invention can be used in an amount of 15 to 50% by weight relative to cement. However, when adjusting the setting time and increasing the permeability, only 2 to 3% by weight of cement should be used.

In addition, the material that should not be confused with vinyl acetate-ethylene is ethylene vinyl acetate (EVA; Ethylene Vinyl Acetate). EVA is mixed with 10 to 40% of vinyl acetate and 60 to 90% dml of ethylene. VAE and EVA have different properties and are treated as different materials because the materials participating in copolymerization are the same but the content ratio is completely different. For example, EVA is dissolved and used in a mold for injection molding in a solid state, but VAE differs in that it is used in an emulsion form.

In the present invention, VAE may be used alone as the polymer emulsion. It may also be used in combination with other polymers used in so-called polymer-modified concrete such as styrene-butadiene rubber or acrylic emulsion. However, even when mixed with polymers such as styrene-butadiene rubber or acrylic emulsion, the content of VAE is used in excess of 50% in the entire polymer emulsion. For example, in the entire polymer emulsion, VAE is contained in an amount of 50.1 to 99.9 wt%, and styrene-butadiene rubber and acrylic polymer are mixed singly or as a mixture in a proportion of 0.1 to 49.1 wt%.

An important point in using the polymer emulsion containing VAE as a concrete modifier is the mixing ratio. Even if the same materials are mixed, the physical properties of the concrete are very different depending on the mixing ratio. The present invention is characterized in that the polymer emulsion is blended in a range of 3 to 9 wt% with respect to the entire concrete composition in which cement, aggregate, water and polymer emulsion (VAE emulsion) are mixed. Such blending ratio is obtained through a number of experiments by the researchers of the present invention. If the compounding ratio of the polymer emulsion is less than the above range, the physical properties of the concrete such as compressive strength, crack resistance and salt resistance can not be formed in a state suitable for the cross- not. In addition, if the compounding ratio of the polymer emulsion exceeds the above-mentioned range, not only the economical efficiency is lowered but also the fluidity of the concrete is drastically lowered, resulting in a problem in workability. Accordingly, it was determined that the polymer emulsion was blended in the range of 3 to 9 wt% in the present invention.

On the other hand, when the conventional polymer modified concrete composition is used to pack the bridges, the polymer-modified concrete is hardened within a very short time (about 30 minutes) after the mixing, so that the concrete can not be manufactured in the ready- Using a mobile mixer. Therefore, it was found that the construction speed was lowered, the concrete properties were limited, and the quality control of concrete was difficult.

In order to solve such a problem, the present invention allows concrete to be manufactured in a concrete mixer or in a concrete mixer plant or in a field plant. Because concrete can be manufactured in ready-mixed concrete factory or plant, it can be mass-produced in a short period of time.

In addition, when the concrete is manufactured at a factory, it is possible to add various mixed materials such as blast furnace slag powder, silica fume, and fly ash, and admixture, thereby improving the physical properties of concrete to be suitable for bridge packaging.

And, when the concrete is manufactured at the factory, the water content of the aggregate can be kept constant and the quality is guaranteed.

In other words, when concrete for bridge pavement is manufactured in a ready-mixed concrete factory or plant, there are various advantages compared with those manufactured by a mobile mixer.

In the present invention, the modifier is mixed with the polymer emulsion so as not to be hardened within a predetermined time so as to sufficiently secure the working time including the time for transporting the concrete for pavement packing from the factory to the bridge site. The polymer emulsion modifier includes at least one of a polycarboxylic acid-based surfactant for preventing cement aggregation or a water-dispersible urethane-based surfactant for preventing cement aggregation. And nonionic surface active agents for preventing cement agglomeration. Optionally, the cement hydration retardant can also be mixed.

The polycarboxylic acid-based surfactant for preventing cement agglomeration is a copolymer of polyethylene glycol mono (meth) allyl ether and maleic anhydride, a copolymer of phenol mono (meth) allyl ether and (meth) acrylic acid, a polyalkylene glycol mono (meth) (Meth) acrylic acid copolymer, a methacrylic ester having a sulfonic acid group, a (meth) acrylic acid copolymer, and a polyglycerin (meth) acrylic acid ester copolymer.

The water-dispersible urethane surfactant can be added to the polymer emulsion together with the polycarboxylic acid surfactant or alone. As the water-dispersed urethane surfactant, a modified water-dispersed polyurethane copolymer can be used.

In the present invention, the above polycarboxylic acid type and / or urethane type surfactant is mixed with a nonionic surfactant for preventing cement aggregation. The non-ionic surfactant for preventing cement agglomeration includes a fatty acid diethanolamine compound, amine oxide, nonylphenol ethylene oxide adduct, sorbitan esterified compound, alkylpolyglycoside, fatty acid ethylene oxide adduct, polyethylene oxide, polypropylene oxide, polyethylene (C12 to C22) diethanolamine compounds, higher fatty acid (C12 to C22) ethylene oxide (EO) adducts (EO is 1 to 50), alkyl (C4 to C20) amine oxides, alkyl (C4 to C20) phenol ethylene oxide adducts (EO is 1 to 50), sorbitan esterified compounds and ethylene oxide adducts (EO is 1 to 50), alkyl (C1 to C20) polyclicosides (Molecular weight: 100 to 100,000), polyethylene oxide and polypropylene oxide (molecular weight: 100 to 100,000), ethylene oxide (ethylene oxide) ball Polymer (molecular weight of 100 ~ 100,000), and at least any one or two or more mixture of polyethyleneimine (molecular weight of 100 ~ 100,000), polyglycerol (molecular weight of 100 ~ 100,000).

Also, the polymer emulsion modifier may optionally include a cement hydration retardant, and the cement hydration retardant may be at least one of citric acid, tartaric acid, gluconic acid, glucose, oligosaccharide, sorbitol and molasses, And the cement hydration retardant is added in a proportion of 0.1 to 5% by weight based on the whole polymer emulsion modifier.

As described above, the polymer emulsion modifier to be added to the concrete according to the present invention is mixed with a polycarboxylic acid surfactant, an aqueous dispersion urethane surfactant, a nonionic surfactant and a cement hydration retarder. Many experiments were carried out and the optimal content ratio of each material was derived.

In other words, it has been experimentally observed that the polycarboxylic acid surfactant for preventing cement aggregation is contained in a proportion of 0.1 to 10 wt% based on the total weight of the polymer emulsion, the urethane surfactant is used in a proportion of 0.1 to 5 wt% The surfactant is preferably present in a proportion of 0.1 to 10 wt% of the entire polymer emulsion, and finally the cement hydration retarder is preferably blended in a proportion of 0.1 to 5 wt% based on the total weight of the polymer emulsion.

If the above materials are added below the mixing ratios of the respective materials, the effect of retarding the coagulation of the concrete is small and the desired working time can not be secured. If the mixing ratio is exceeded, , It is preferable to add the materials within the above range.

In the present invention, the polymer emulsion modifier may further include a shrinkage reducing agent, a coagulation retarder, and an emulsion type antifoaming agent. As the shrinkage reducing agent, polyoxyethylene alkyl aryl ether, polyoxyethylene oxypropylene block copolymer, polyoxyalkylene glycol, alkyl or cycloalkyl polyoxyalkylene may be used. The shrinkage reducing agent may be blended in an amount of 0.1 to 3% by weight based on the whole polymer emulsion modifier.

As the coagulation retarder, tartaric acid, citric acid, sodium gluconate, and sugar may be blended in the range of 0.1 to 1% by weight in the entire polymer emulsion, respectively. The antifoaming agent is blended in the range of 0.1 to 10% by weight based on the whole polymer emulsion modifier.

When the polymer emulsion modifier of the composition as described above is used in concrete, the slump and flow reduction of the concrete are considerably lowered, so that the concrete can be installed for at least 1 hour and up to 2 hours after mixing the concrete. If the fluidity of the concrete is maintained up to 1 ~ 2 hours, the concrete installation work and the jointing work time including the transportation time and waiting time from the concrete factory or the site plant to the bridge can be sufficiently secured. .

When the polymer emulsion modifier having the above composition is used, the condensation of the concrete is delayed, so that a sufficient working time for laying the concrete on the road surface can be secured, and the physical properties of the concrete are also improved. That is, the solid part of the polymer (VAE, SBR) is uniformly dispersed in the concrete to form a polymer film, thereby improving the flexural toughness and adhesion strength of the concrete and greatly preventing diffusion of chlorine ions.

Also, since the polymer-modified concrete according to the present invention is manufactured in a concrete mixer factory or a field-disposing plant, it is possible to freely use a storage facility and a metering facility for various materials, so that various materials can be mixed with cement .

For example, various mixed materials such as blast furnace slag fine powder, fly ash, and silica fume, an admixture and an additive can be freely mixed to produce a concrete excellent in chemical resistance and salt resistance.

For example, blast furnace slag powders generate Ca ^{2 +} , Mg ^{2 +} , AlO ₄ ^{4 -} , and SiO ₄ ^{4 -} ions during hydration which react with cement hydrate to form calcium silicate (CSH), calcium aluminate (CAH10) , The alkaline amount of cement is decreased and the cement interior is dense to improve the long - term strength and water tightness, and adsorbs Cl ^- ions and blocks the inflow of Ca ^{2 +} ions from the calcium chloride - containing cleaning agent.

The components of SiO ₂ and Al ₂ O ₃ of fly ash absorb the alkali component of the cement through the pozzolanic reaction with the cement hydrate and make the internal structure of the cured product dense and the aluminum component absorbs the Cl ^- adsorption and blocks the inflow of Ca ^{2 +} ions. That is, it is possible to improve the permeability of the concrete by filling the voids in the cement paste by fixing the calcium hydroxide or the alkali hydroxide mixture which is present in the void structure in the cement paste with the permeating water and is precipitated with the hydrated living material of the cement, Thereby contributing to the improvement of the strength and durability of the concrete.

Silica fume contains more than 80% of silica mainly amorphous crystals and it is composed of very fine and spherical particles (mean particle diameter 0.1 μm), which has a positive effect on the long-term strength increase of concrete because it causes pozzolanic reaction very effectively. Particularly, since the particle size is small enough to form the silica fume having a specific surface area of 150,000 to 250,000 cm 2 / g, the waterproof effect is improved by filling the space between the cement paste and the aggregate. It is possible to maintain watertightness and chloride ion permeability, which are important for concrete for pavement pavement, without additional waterproofing treatment.

In order to confirm the effect of the polymer-modified concrete having the above-described constitution, a physical property test was performed.

In the experiment, the concrete composition according to Examples 1 to 3 containing the VAE emulsion according to the present invention and the concrete composition according to the comparative example in which the VAE emulsion was not included and the conventional SBR was used as the polymer emulsion were prepared. The concrete compositions according to Examples 1 to 3 and Comparative Examples are shown in the table of FIG. Referring to the table of FIG. 3, VAE emulsion alone was included in Example 1, and VAE and SBR were used together as polymer emulsions in Examples 2 and 3. In Examples 2 and 3, a modifier such as a polycarboxylic acid surfactant was used. In Example 1, the modifier was not mixed. In the physical properties test, the slump, the air content, the compressive strength, the chloride ion permeation amount, the length change, and the crack resistance were measured. The results are shown in the table of FIG.

The results will be described with reference to the table of FIG.

In the case of the slump (mm), 60 minutes after the mixing of the concrete showed almost no flow in the comparative example and the example 1. However, in the case of the examples 2 and 3, it was confirmed that the fluidity was secured at a level similar to that of the initial slump Respectively. If the slump above 170 mm is secured even after 90 minutes, concrete can be supplied to concrete site by using concrete or plant without using a mobile mixer car. In addition, when concrete and plant are used, it is possible to mix various additives and admixture together, so that it is possible to control physical properties of concrete according to the characteristics of pavement pavement.

In the case of the amount of air influencing the resistance to freezing and thawing at the time of concrete installation, the comparative examples and Examples 1 to 3 were all similar. That is, even when the VAE modified concrete composition according to the present invention is used, it is confirmed that the same level as that of the polymer modified concrete using the existing SBR is ensured.

In the case of the compressive strength, the strength of Examples 1 to 3 was lower than that of Comparative Example at one day, but it started to show higher than that of Comparative Example at three days. Moreover, in the 28th day of the ages, the compressive strengths of Examples 2 and 3 exceeded 40 MPa, while the comparative example exhibited 37 MPa, proving that the embodiment according to the present invention is more excellent at long-term compressive strength.

The chlorine ion permeability of Examples 1 to 3 was better than that of Comparative Examples. In particular, the amount of chloride ion permeation was the lowest in Example 3 using the VAE emulsion and the modifier, which is considered to be due to the moisture resistance of the VAE emulsion.

Penetration resistance (chlorine ion permeability) to salinity is generally inadequate due to too high chlorine ion permeability if its value is above 4,000 coulombs, and is considered good if it is in the range of 4,000 to 2,000 coulombs. The comparative examples and Examples 1 to 3 were all at a satisfactory level, but Examples 2 and 3 were the most excellent.

In the case of the length variation, the comparative examples and the examples were all at the same level, and cracks were not found in the specimens according to the comparative examples and the examples in the crack resistance.

When the VAE emulsion is used as a polymer emulsion according to the present invention, when concrete is formed, at least the same level as that of the existing SBR modified concrete is exhibited in the physical properties required in the cross-pavement packaging, and the slump, compressive strength, It has been confirmed that the ionic resistance is superior to that of conventional polymer modified concrete. From these experimental results, it has been proved that the present invention is excellent not only in the long-term properties of the cross-linked pavement but also in the workability. Further, in the present invention, by using VAE, concrete can be manufactured much more economically than SBR, and it is advantageous that stable supply and demand can be achieved.

Further, since the fluidity of the concrete is increased by using a polycarboxylic acid-based surfactant or the like, the present invention can be used to manufacture concrete in a factory or mix it with a concrete mixer without depending on a mobile mixer car. When the concrete is manufactured in factories, various mixed materials can be added, which has an advantage that the chemical resistance, salt resistance and durability of the concrete can be increased.

In the bridge pavement method using the concrete composition according to the present invention, polymer-modified concrete is installed on the surface of a bridge after the surface of a bridge to be packaged is cleaned, and the concrete is cured.

More specifically, in order to package a bridge using a concrete composition for a bridge pavement, a surface cleaning operation for removing contaminants attached to the bridge surface and aggregate exposed on the surface of the bridge should be preceded. Such surface cleaning work is usually carried out within 48 hours prior to concrete pouring. Also, before the concrete is poured, the surface of the bridge is wetted with water and then dried to saturate the surface, thereby preventing moisture from being absorbed into the existing concrete.

When the pre-pavement preparation work is completed as described above, concrete for pavement pavement is installed. When the concrete is installed in this manner, the surface is flattened using a vibrator or the like, and the surface finishing is performed through an electric finishing or a manual operation. At this time, depending on the construction situation, texuring can be carried out by using Astroturf drag or the like on the surface where the concrete is poured.

Finally, the coating film is applied to the upper part of the concrete pouring surface, and the polyethylene film is coated on the upper part of the concrete pouring surface, and the pavement pavement using the concrete composition for pavement paving is completed.

Meanwhile, another embodiment of the present invention provides a VAE modified mortar composition.

The VAE modified mortar composition is the same in all parts compared to the concrete composition described above, except that only coarse aggregate such as sand is used without using coarse aggregate such as gravel, and there is only a slight difference in the mixing ratio only. The compounding ratio is

In the case of mortar, 15 to 40% by weight of cement, 40 to 75% by weight of fine aggregate, 3 to 12% by weight of water and 4 to 10% by weight of polymer emulsion are mixed. Compared with the concrete composition, coarse aggregate was excluded, and thus the blend ratio of cement, fine aggregate, and the like slightly changed, but this is due to the difference between the mortar and concrete. A detailed description thereof will be omitted.

FIG. 5 is a table showing the mixing ratio of samples for testing the physical properties of the VAE modified mortar according to the invention, and FIG. 6 is a table showing the results of the physical properties of the VAE modified mortar using the samples shown in FIG. to be.

As shown in the table of FIG. 5, the present inventors experimented with the VAE modified mortar composition by preparing compositions according to Examples 1 to 3 including VAE and Comparative Examples containing only SBR. Experimental items are flow and compressive strength, which are the most important factors in polymer modified mortar.

Referring to the experimental results shown in the table of FIG. 6, in the case of the comparative example in which SBR alone was added, the flow rate was significantly lowered after 60 minutes, and the flowability dropped to such an extent that the flow could not be measured 90 minutes later. In Example 1, the polymer modifier was not included, and the flow value dropped after 60 minutes passed. However, according to the optimum embodiment of the present invention, in Examples 2 and 3 in which modifiers were mixed together with VAE, the flowability was about 185 mm even after 90 minutes passed, Respectively.

From the standpoint of compressive strength, the initial compressive strengths of Examples 1 to 3 were slightly lower than those of Comparative Examples in the same day, but it was confirmed that the long-term compressive strengths of 3 and 28 days old were excellent.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation and that those skilled in the art will recognize that various modifications and equivalent arrangements may be made therein. It will be possible. Accordingly, the true scope of protection of the present invention should be determined only by the appended claims.

Claims (10)

A polymer-modified cement composition comprising cement, aggregate, polymer emulsion and water mixed therein,
Wherein the polymer emulsion comprises a vinyl acetate-ethylene (VAE) copolymer. The method according to claim 1,
Wherein the composition is mixed in an amount of 5 to 20% by weight of cement, 67 to 90% by weight of aggregate, 1 to 6% by weight of water and 2 to 10% by weight of polymer emulsion. The method according to claim 1,
Wherein the cement composition is mixed in a range of 15 to 40 wt% of cement, 40 to 75 wt% of fine aggregate, 3 to 12 wt% of water and 4 to 10 wt% of polymer emulsion. The method according to claim 1,
Wherein the polymer emulsion is further blended with at least one of styrene butadiene rubber (SBR) and acrylic. 5. The method of claim 4,
Wherein the polymer emulsion is mixed in an amount of 50.1 to 99.9 wt% of the vinyl acetate-ethylene, and 0.1 to 49.9 wt% of any one or combination of styrene butadiene rubber and acrylic. The method according to claim 1,
Wherein the polymer emulsion further comprises a polymer modifier, wherein the polymer emulsion is mixed in the range of 0.1 to 10 wt% in the entire polymer emulsion. The method according to claim 1,
Wherein the vinyl acetate-ethylene copolymer is used by mixing a plurality of different ones having different glass transition temperatures. 8. The method of claim 7,
Wherein the vinyl acetate-ethylene copolymer has a glass transition temperature lower than 0 占 폚 in comparison with a subzero temperature. 8. The method of claim 7,
Wherein the vinyl acetate-ethylene copolymer has a glass transition temperature of 30 占 폚 or higher as compared with a high temperature. 8. The method of claim 7,
The vinyl acetate-ethylene copolymer is mixed with three different glass transition temperatures, and the glass transition temperature is in the range of -50 to -20 ° C, -20 to 30 ° C, and 30 to 60 ° C, respectively ≪ / RTI > VAE modified cement composition.

Images