KR102335008B1 - Additive for high early strength cement comprising modified sulfur binder, method for preparing the same, high early strength cement conctrete composition comprising the same, and high early strength cement conctrete composition - Google Patents

Abstract

The present invention provides an additive for high early strength cement comprising a resin, rubber, or a combination thereof, and a modified sulfur binder, a method for manufacturing the additive, a high early strength cement composition comprising the same, and a high early strength cement concrete composition comprising the same. The additive of the present invention can improve the durability performance of a concrete structure by suppressing the occurrence of microcracks in the concrete and increasing the watertightness of the concrete.

Description

BACKGROUND OF THE INVENTION 1. High-speed cement additives comprising a modified sulfur binder; , METHOD FOR PREPARING THE SAME, HIGH EARLY STRENGTH CEMENT CONCTRETE COMPOSITION COMPRISING THE SAME, AND HIGH EARLY STRENGTH CEMENT CONCTRETE COMPOSITION}

The present invention relates to an additive for cementing per second containing a modified sulfur binder, a method for preparing the additive, a cement composition for cementing per second and a cement composition for cementing per minute per second including the additive, and more particularly, to a cementitious composition at a temperature of 100° C. or less. The present invention relates to an additive for cementing per second prepared by using a modified sulfur binder having re-melting properties, a method for producing the same, and a cement composition for cementing per second and perforation and a cement and concrete composition comprising the additive.

Sulfur is one of the non-metal elements and is frequently generated during the desulfurization process of crude oil or natural gas. Rather than treating sulfur generated during the desulfurization process of crude oil or natural gas as simple industrial waste, many studies are being conducted to utilize it in various industrial fields. In particular, recently, a technique for improving the performance of construction materials by using sulfur instead of or together with conventional construction materials has been developed and used.

However, the physical properties of sulfur are that it dissolves at a temperature of 119°C or higher and is a solid at room temperature. In addition, the flash point is 207 ℃, the spontaneous ignition temperature is 245 ℃, there are problems such as having ignitability, there was a disadvantage that it is difficult to actually use in various industrial fields such as construction materials.

Although various technologies have been developed to improve the disadvantages of sulfur, there are disadvantages such as difficulty in controlling the reaction of sulfur in physical properties and rapidly becoming solid at room temperature and thus cannot be molded. In particular, there are many research and development efforts on modified sulfur binders that have improved physical properties by adding various substances to sulfur, but it is still difficult to control the reaction, and the disadvantages that it cannot be molded because it rapidly becomes solid at room temperature are not solved.

Accordingly, as an invention completed by the present inventor, Korean Patent Application No. 2007-0062430 has been filed and registered for a modified sulfur binder capable of overcoming the problems of the conventional modified sulfur binder and a method for manufacturing the same. The modified sulfur binder disclosed in the patent application can be remelted at a temperature of 100° C. or less, which is the evaporation temperature of water, and the modified sulfur binder, which is usually hydrophobic, can be completely dissolved in water of 100° C. or less. In addition, it can be changed according to the range of the addition amount of sulfur and additives, and has excellent performance in strength, waterproofness, chemical resistance, elasticity, fire resistance and non-explosion resistance.

On the other hand, super-velocity cement is generally called jet cement, etc., and is a type of special cement that reaches a compressive strength of 150 to 250 kgf/cm 2 in 2 to 3 hours. While the setting time has a very short setting time within 2 to 3 hours, in terms of expressed strength, it is relatively higher than that of super-strength cement, which is stronger than ordinary ordinary cement, and has a strength comparable to that of ordinary cement.

Since such cements can express strength in a shorter period of time than ordinary cements, they are used in various fields where time must be shortened by forming a concrete composition using cement using super-velocity cement. For example, in the repair work of a road paved with cement concrete, the use of ultra-fast cement concrete can achieve effects such as reducing traffic blocking time, and it is also widely used in runway repair work, general civil engineering, and building work. .

However, the concrete containing the super-velocity cement generates a high heat of hydration for early strength development compared to the concrete containing the general cement, and microcracks occur due to temperature stress and shrinkage according to the movement of heat and moisture in the concrete. There is a problem that the water permeability of concrete is increased due to these microcracks, thereby reducing the durability of the concrete structure. In addition, there is a problem in that the production cost of cement per second is high, so that it is limitedly used only for emergency repair work of roads or emergency repair works of runways.

In order to solve the conventional problems as described above, the present invention provides an additive for super-velocity cement comprising a modified sulfur binder capable of improving the durability of a concrete structure by suppressing the occurrence of microcracks to increase the watertightness of concrete, and the It is to provide a manufacturing method, a cement composition for cement per second and a cement composition for cement per second including the additive.

In addition, it is relatively inexpensive to provide an additive for cementing per second including a modified sulfur binder that can be widely used in various fields, a method for manufacturing the same, cement composition containing the additive, and cement concrete composition will be.

Other objects of the present invention will be easily understood through the description of the following embodiments.

According to one aspect of the present invention, resin, rubber, or a combination thereof; And there is provided an additive for cementing the super-fast cement comprising a modified sulfur binder.

According to another aspect of the present invention, a powder consisting of a resin, rubber, or a combination thereof; and mixing the modified sulfur binder at a temperature of 80° C. or higher and 200° C. or lower.

According to another aspect of the present invention, there is provided a cement composition for cement per second and a cement composition for cement and concrete composition per second per second, including the additives for cement at per second prepared according to the present invention.

According to the present invention, there is provided an additive for cement with super-velocity cement, in which the bonding strength with concrete is remarkably improved by the graft reaction of rubber and/or resin with a modified sulfur binder, and the additive of the present invention suppresses the occurrence of microcracks in concrete, It is possible to improve the durability performance of concrete structures by increasing the watertightness of concrete.

1 (a) is a photograph of the surface of concrete obtained from the concrete composition containing the general cement of Comparative Example 1, and FIG. 1 (b) is a photograph of the surface of the concrete obtained from the concrete composition containing the cement of Comparative Example 2. and FIG. 1 ( c ) is an electron micrograph of a cross section of concrete obtained from the concrete composition including the crude steel cement obtained in Example 2.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiment of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below.

According to the present invention, when the cement per second cement additive is mixed with concrete, it is possible to suppress the occurrence of micro cracks in the cement per second cement to increase the watertightness of the concrete, thereby improving the durability performance of the concrete structure.

The additive for cementing per second of the present invention includes a resin, rubber or a combination thereof and a modified sulfur binder.

The modified sulfur binder that can be applied in the present invention is sulfur and a modifier of the sulfur, 1) 10 to 100 parts by weight of a dicyclopentadiene modifier, 2) a heterocyclic ring with respect to 100 parts by weight of the sulfur 0.1 to 50 parts by weight of amines or quaternary ammonium salts are melt-mixed, and the heterocyclic amines are at least one selected from the group consisting of pyridine, a pyridine homologue, quinoline and isoquinoline. As one characterized in that, the content related to the modified sulfur binder described in Korean Patent Application No. 2007-0062430 is incorporated herein in its entirety.

More specifically, in the present specification, the meaning of "modified sulfur binder" is, in order to modify sulfur, in sulfur, as a sulfur modifier, heterocyclic amines or quaternary ammonium salts, and a dicyclopentadiene-based modifier. refers to both the modified sulfur binder and the solid modified sulfur binder obtained by cooling the liquid modified sulfur binder to room temperature.

At this time, the sulfur is normal sulfur, and the sulfur includes natural sulfur or sulfur produced by desulfurization of petroleum or natural gas, and the sulfur is heated and melted at 120 ° C. or higher, preferably 125 to 140 ° C. One molten sulfur may be used.

As disclosed in Korean Patent Publication No. 2006-101878, the dicyclopentadiene-based modifier includes dicyclopentadiene (DCPD) as a modifier. This DCPD may be used alone, or cyclopentadiene (CPD); DCPD derivatives; A mixture to which at least one of a CPD derivative such as methylcyclopentadiene (MCP) or methyldicyclopentadiene (MDCP) is added may be used. As an exemplary composition of such a dicyclopentadiene-based modifier, about 65 to 75% by weight of DCPD, about 10 to 20% by weight of CPD, about 10 to 20% by weight of derivatives thereof (MCP, MDCP, etc.), and about 0.1 to about other components 1.5% by weight. In addition, the dicyclopentadiene-based modifier may be used in a mixed form with an olefin compound such as dipentene, vinyl toluene, styrene monomer, and dicyclo pentene. As disclosed in Japanese Patent Application Laid-Open No. 2002-60491 and Korean Patent Application Laid-Open No. 2005-0026021, the dicyclopentadiene-based modifier has a DCPD content of about 70% by weight (this is referred to as "purity of 70%") or more. It is preferable, and most of the commercial items called so-called dicyclopentadiene can be used.

The heterocyclic amines include at least one selected from the group consisting of pyridine, pyridine homologues, quinoline and isoquinoline.

Meanwhile, the quaternary ammonium salt may be selected from the group consisting of alkyltrimethyl ammonium chloride, alkyldimethylbenzyl ammonium chloride, and alkyldimethylmetharyl ammonium chloride.

Such a solid modified sulfur binder is characterized in that it can be re-melted at a temperature of 100 °C or less. The melting point of the modified sulfur binder is preferably 50°C to 100°C, for example, 80°C to 100°C.

On the other hand, the resin, rubber, or a combination thereof is preferably a powder having an average particle size of 0.1 to 5 mm, for example, a powder having an average particle size of 0.3 to 3 mm. More preferably, it is 0.1 to 3 mm similar to the size of the aggregate, for example, it may be in the range of 0.3 to 0.5 mm or 0.8 to 1.2 mm.

The method of controlling the particle size of the powder is not particularly limited, and for example, the size of the particle size may be selected through sieving after freeze-pulverization.

When the powder particles of the resin, rubber, or a combination thereof exceed 5 mm, compressive strength may be rather reduced when added to the concrete composition afterward. Agglomeration may occur due to the lowering of the chemical composition, and phase separation may occur due to a difference in specific gravity. However, when the powder particles of rubber or a combination thereof exceed 5 mm, it can be used in the manufacture of rubber pavement blocks with coarse concrete structures, for example, concrete for sidewalk blocks. The size of the rubber powder particles is 'fine rubber powder' if the diameter is smaller than this based on the particle size of the fine aggregate among the size of aggregates used in cement raw materials, and the rubber powder larger than the size of the fine aggregate is called 'coarse rubber powder'. can be referred to

In the case of using the super-velocity cement additive of the present invention, it is possible to obtain a resin, rubber, or a combination thereof whose surface is modified and/or grafted with a modified sulfur binder, and in the present specification, the modified sulfur binder obtained as a result is used. Modified and/or grafted resins, rubbers, or combinations thereof may be referred to as 'additives for super-velocity cement'.

Since rubber has hydrophobic properties, especially when added to concrete, there is a problem in that the compressive strength of concrete is rapidly lowered due to phase separation due to the difference in specific gravity and the difference between hydrophilicity and hydrophobicity. Accordingly, in the present invention, a hydrophilic group derived from a modified sulfur binder and a reactive group are given to the surface of the resin and rubber by using a resin, rubber, or a combination thereof modified and/or grafted with a modified sulfur binder. When used as an additive in cement, resin and rubber It can form a miscibility and reaction point for the powder of cement.

The additive for super-velocity cement of the present invention can form an elastic body in which modified sulfur is graft-reacted on the surface of the resin and/or rubber to maintain elasticity and durability through chemical reaction with concrete thereafter. Phase separation from concrete can be minimized by such surface treatment.

That is, when powder such as rubber is simply mixed with concrete, the physical strength of concrete may be lowered due to phase separation, but the additive for super-velocity cement of the present invention prevents the occurrence of fine cracks in concrete by surface treatment of the modified sulfur binder. It is possible to improve the durability performance of concrete structures by increasing the watertightness of concrete by suppressing it.

The modified sulfur binder is preferably included in an amount of 1 to 10 parts by weight per 1 part by weight of resin, rubber, or a combination thereof, for example, 2 to 4 parts by weight or about 3 parts by weight. In the super-velocity cement additive, when the modified sulfur binder is less than the above range, there is an insufficient problem of surface modification of the resin, rubber, or a combination thereof. There is a risk of occurrence, and the phenomenon of aggregation of rubber particles may occur, which may lead to cracks in the concrete.

The rubber that can be used in the present invention is not particularly limited, but EPDM rubber (ethylene propylene diene methylene rubber), SBR (Styrene Butadiene Rubber), NBR (Nitryl Butadiene Rubber), waste tires, etc. may be used, and the waste tires may include , For example, as a rubber as a main material and may include a tire cord yarn, etc., if it is such a waste tire, it is not particularly limited. In this case, the material of the tire cord yarn may be, for example, polyethylene (PE), polyethylene terephthalate (PET), nylon, or the like.

Meanwhile, the resin that can be used in the present invention may be selected from the group consisting of ethylene vinyl acetate (EVA), unsaturated polyester, polybutadiene compound, and the like, but is not limited thereto.

The resin may be in powder form and/or fiber form, and is preferably ethoxylated. In this case, the ethoxylation may be ethoxylated through a step of dipping the resin in an ethoxy compound.

When the resin is in the form of a fiber, the role of a reinforcing yarn capable of maintaining elasticity as an organic composite material can be enhanced, and the length of the fiber is preferably about 1 to 50 mm, for example, 3 to 15 mm. more preferably. If the length of the fiber exceeds 50 mm, entanglement and agglomeration of the fibers occur when mixing with the concrete material thereafter, and there is a possibility of phase separation. In this case, the average diameter of the fibers may be about 20 to 35㎛.

Meanwhile, dicyclopentadiene may be additionally included in the additive for cementing at very high speed of the present invention, and in this case, the dicyclopentadiene may be included in an amount of 0.1 to 0.5% by weight based on the total weight of the additive for cementing at very high speed. . DCPD can maintain the form of a graft polymer by thermally reacting with the sulfur on the modified surface with a modified sulfur binder to provide additional bonding strength. For example, when using waste rubber, crosslinked rubber powder In order to improve the elasticity of the rubber, DCPD can be additionally added to soften and activate the waste rubber powder to restore the elasticity of the rubber. However, when dicyclopentadiene is contained in excess, rubber elasticity may be reduced due to plasticization of rubber powder with free sulfur that does not react with rubber powder, that is, sulfur that has not undergone a crosslinking reaction.

Furthermore, according to the present invention, there is provided a method for producing an additive for cementing per second cement, the method comprising: a powder made of a resin, rubber, or a combination thereof; And it will include the step of mixing the modified sulfur binder at a temperature of 80 ℃ or more and 200 ℃ or less.

In the method for producing an additive for cementing per second of the present invention, a resin, rubber, or a combination thereof; And the content of the super-fast cement additive containing the modified sulfur binder is applied as it is.

The manufacturing method of the additive for super-velocity cement includes: heating a powder made of a resin, rubber, or a combination thereof at a temperature of 80°C or higher and 200°C or lower; and adding and mixing the modified sulfur binder.

The heating step activates the powder made of resin, rubber, or a combination thereof, and is heated to a temperature of 80°C or higher and 200°C or lower, preferably 100°C to 160°C, for example, 100°C to 150°C. It is preferable to activate the surface by rubbing the surface together with the heating, for example by stirring or rotating. An electrostatic charge is formed on the surface by activation by such friction to generate charged ions, and then an ionic reaction is performed when in contact with the modified sulfur binder. In this case, in the step of heating the powder made of resin, rubber, or a combination thereof, the stirring may be performed by rotation, for example, may be performed in the range of 800 to 1,200 rpm.

The heating may be performed for 1 to 20 minutes, for example, 3 to 15 minutes, preferably 7 to 10 minutes.

Since the resin, rubber, or a combination thereof is phase-separated from the cement material, it is necessary to modify the surface to impart hydrophilicity, and for this purpose, a material having excellent compatibility with cement may be added or modified. According to the present invention, the step of mixing the surface-activated resin and/or rubber with the modified sulfur binder is performed, wherein the temperature is preferably a temperature equal to or higher than the melting point of the modified sulfur binder, for example, 50 ° C. to 100 ° C., for example For example, it is 80 °C to 100 °C. That is, it is preferable that the modified sulfur binder to be mixed at this time is melted and is in a fluidized bed.

This mixing step may be performed for 1 minute to 10 minutes, for example, 1 minute to 5 minutes, preferably may be performed for 2 minutes to 4 minutes.

On the other hand, the method of adding the modified sulfur binder in the mixing step is not particularly limited, but for example, melt-modified sulfur may be added by spraying.

By mixing the surface-activated resin and/or rubber with the modified sulfur binder, the modified sulfur binder reacts with the resin and/or rubber surface, and the tissue density increases by tacking action, binding As a result of the action, the bonding strength with cement and the like is increased.

Subsequent to the step of adding and mixing the modified sulfur binder, the step of further adding dicyclopentadiene may be performed.

Furthermore, the method for producing an additive for cement at very high speed of the present invention comprises the steps of: cooling the additive for cement at high speed at high speed obtained by the mixing step to below room temperature; and cutting the cooled additive for super-velocity cement, wherein the cooling temperature is not particularly limited, but for example, a temperature of -20°C to room temperature, preferably -20 to 35°C or less. , for example greater than 0 to 25°C. In this case, the room temperature may mean a temperature of 25 °C to 35 °C.

Meanwhile, the heating and/or mixing may be performed in a mixer accompanied by stirring, for example, a Henschel mixer may be used.

According to another aspect of the present invention, there is provided a cementitious cement composition comprising the cementitious cementitious additive prepared according to the present invention, and a cementitious cementitious composition comprising the cementitious velocity cement composition.

The cementing per second cement composition of the present invention includes a powder made of a resin, rubber, or a combination thereof, the surface of which is modified by a modified sulfur binder, and more specifically includes cement and water, and the cement composition of the present invention Based on 100 parts by weight of silver cement, 0.1 to 5 parts by weight of resin, rubber, or a combination thereof; and 0.5 to 20 parts by weight of the modified sulfur binder, for example, 2 to 7 parts by weight of the modified sulfur binder.

On the other hand, the cementitious cement composition of the present invention includes a powder made of a resin, rubber, or a combination thereof, the surface of which is modified by a modified sulfur binder, and more specifically, cement, fine aggregate, coarse aggregate and water. will be.

The additive for cementing per second cement is included in an amount of 0.1 to 35 parts by weight, for example, 0.1 to 20 parts by weight, based on 100 parts by weight of the cement used in the cementitious super fast cement composition. When the super-velocity cement concrete additive is included below the above range, it is difficult to obtain the effect of improving the watertightness of concrete due to suppression of the occurrence of microcracks in the concrete, and thus it is difficult to secure the effect of improving the durability of the concrete structure. On the other hand, when the content exceeds the above range, the specific gravity of the rubber particles treated with the modified sulfur binder is low, which may cause phase separation between the rubber particles and the cement concrete composition with super-velocity.

According to the present invention, there is provided a super-velocity cement concrete composition in which the bonding strength with concrete is significantly improved by the graft reaction of rubber and resin with a modified sulfur binder, and thus waterproofness, electrical insulation, adhesion and chemical stability can be further improved. It is possible to achieve early strength development, which is the original purpose of ultra-fast cement concrete.

On the other hand, in the cement composition or cement concrete composition with high cementation per second of the present invention, workability may be lowered due to increased initial hydration, and a retarder may be added as necessary to secure workability.

The cement composition for cement composition or cement concrete composition for cementing per second according to the present invention can express the strength desired by the cement concrete composition, as well as prevent the occurrence of microcracks due to the use of the additive. can be significantly reduced. Therefore, when performing road pavement repair work, etc. using the cementitious cement concrete composition according to a preferred embodiment of the present invention for road pavement repair work, the effect of increasing the watertightness due to the adhesive force of the cement per second cement additive is provided. can

On the other hand, in the case of including the addition of the super-velocity cement additive to the super-velocity cement concrete composition, the amount of fine aggregate and/or coarse aggregate may be reduced by an amount corresponding thereto.

As the fine and coarse aggregates that can be used in the present invention, known fine and coarse aggregates may be used within a known content range, and for example, the fine and coarse aggregates may be sand, gravel, or the like.

Furthermore, in the present invention, at least a part or all of the fine aggregate may be replaced with a metal ball formed with a particle size (particle size) in the same range as the particle size commonly used as the fine aggregate, and in this case, the material of the metal ball is not particularly limited if it is a metal. , for example an iron ball can be used. As such, when a metal ball is used as a fine aggregate, the absorption coefficient can be improved in a high frequency region.

Example

1. Manufacture of concrete

(1) Preparation of modified sulfur binder

A 3-neck type glass reactor for 500 ml was manufactured in a thermostat (silicone oil used as a heat medium) in which a constant temperature is maintained by PID (automatic temperature control) method. 300 g of industrial powder sulfur was put into the reactor to melt the sulfur at about 130° C., and 60 g of dicyclopentadiene (a raw material for industrial use with a purity of 85%) was slowly added within about 5 to 10 minutes while stirring the reactor impeller. At this time, stirring was carried out for 40 minutes while maintaining the reaction temperature at 136° C. while paying attention to the sudden rise in temperature due to the exothermic reaction.

When the color of the reaction product changes from an opaque state to dark red when the reaction is carried out for 10 to 20 minutes at the point when the color of the reaction product becomes dark from the transparent state of orange (that is, the time when the precursor starts to be formed), 30 g of pyridine is slowly added Let the reaction proceed. As the reaction time progresses, the color becomes darker and the viscosity begins to form, open one 3-neck stopper and proceed with the vaporization of pyridine. As the pyridine gradually evaporated, the smell almost disappeared and the color changed to dark color (pyridine vaporization time was 30 minutes), and the final reaction temperature was 140 ° C. At this time, the reaction was terminated and cooled at room temperature to obtain a solid modified sulfur binder. prepared. The re-melting temperature of the prepared solid modified sulfur binder was about 85 °C.

(2) Manufacture of additives for super-velocity cement

The additive for super-velocity cement is obtained by reacting the surface of rubber powder obtained by cutting rubber to a particle size of about 1 to 3 mm with the modified sulfur binder obtained from (1) above.

More specifically, the rubber powder is put into a Henschel mixer heated to 100~150℃ and rotated at 800~1,200 rpm for 3 to 10 minutes to activate the rubber surface due to friction between the rubber powders to charge the activated rubber surface to form ions Accordingly, the modified sulfur binder is added to the Henschel mixer to ionically react with the charged ions formed on the surface, so that the super fast cement additive is compatible with the super fast cement concrete composition and has reactivity with the cement mortar. Then, while maintaining the rotation at 800 to 1,200 rpm, the temperature is lowered to -20 to 10° C. and cooled.

The process performed in the Henschel mixer is more specifically, first, a twin screw extruder kneader for rubber powder having a particle size of about 1 to 3 mm, and each extrusion zone of the twin screw extruder as shown in Table 1 below. The temperature was also set and the rubber powder was put into the hopper. At this time, the temperature of the inlet is set to the preheating temperature of the rubber particles, and the temperature is gradually increased so that the decomposed and unvulcanized rubber particles can be processed in area 4, and a side feeding device is attached to the area 4 (1). ) was added to react with the rubber particles.

Temperature conditions for each area of twin screw extruder (℃) hopper Zone 1 Zone 2 Zone 3 Zone 4 Zone 5 Zone 6 die 90 100 125 150 170 150 140 130

(3) Preparation of concrete composition The mixing ratio of the concrete composition is the amount of cement, fine aggregate, coarse aggregate, water, retarder, etc. according to the standard concrete mixing table as shown in Table 2 below. The slump was tested so that the slump value in KS F 2594 was 6 cm, and the amount of air was about 5% in accordance with KS F 2421.

Fine aggregates had an average particle size of 3 mm and coarse aggregates had an average particle size of 19 mm.

For the curing method of the super-velocity cement concrete composition, it was covered with an insulating material so that the temperature did not drop due to atmospheric curing, and then cured sufficiently for 3 hours or more. was cured by underwater curing, and during underwater curing, the concrete test specimen was cured by maintaining a temperature of 20±2℃ before the test.

The following concrete composition A (Comparative Example 1) is a general concrete composition, and the concrete composition B is a concrete composition (Comparative Example 2) in which a modified sulfur binder (E6) is added to the concrete composition A (Comparative Example 2), and the composition is shown in Table 2 below.

Comparative Example Concrete Composition division Unit amount of material (kg/㎥) Cement composition (kg) W C S G retardant THSM TP-C TP-F T.C. P (resin) crude steel cement Comparative Example 1 160 410 878 821 1.54 0 0 0 0 0 410 Comparative Example 2 160 410 878 821 1.54 25 0 0 0 0 385

W: Water, C: Cement, S: Fine aggregate, G: Coarse aggregate, THSM: Modified sulfur binder, TP-C: Coarse rubber powder, TP-F: Fine rubber powder, T.C: Tire cord yarn, P: Resin

On the other hand, the cement concrete composition for super-velocity cement using the super-velocity cement additive of the present invention was prepared as shown in Table 3 below by changing the particle size of rubber powder to the composition shown in Table 3 below, wherein the rubber was used as a powder of waste tire rubber. The fine rubber powder had an average particle size of 1 mm or less, and the coarse rubber powder had an average particle size of 5 mm.

Example concrete composition division Unit amount of material (kg/㎥) Cement composition (kg) W C S G retardant THSM TP-C TP-F T.C. P (resin) crude steel cement Example 1 160 410 878 821 1.54 22.5 2.5 0 0 0 385 Example 2 160 410 878 821 1.54 22.5 0 2.5 0 0 385

W: Water, C: Cement, S: Fine aggregate, G: Coarse aggregate, THSM: Modified sulfur binder, TP-C: Coarse rubber powder, TP-F: Fine rubber powder, T.C: Tire cord yarn, P: Resin

Furthermore, in order to improve the bonding strength of rubber in the tire, an additive for super-velocity cement was prepared by using the inserted nylon tire cord yarn in an unseparated state. At this time, the size of the rubber powder particles containing the tire cord yarn was made into coarse rubber powder particles (the particle size was about 3 to 6 mm), and it was added to the cement prepared.

On the other hand, by adding a small amount of DCPD, it is possible to restore the elasticity of the rubber, which has lost its elasticity due to long-term use and natural environment such as sunlight during the reaction.

Example Initial velocity cement concrete composition - use of rubber powder containing cord yarn division Unit amount of material (kg/㎥) Cement composition (kg) W C S G AE product THSM TP-C TP-F T.C. P (resin) crude steel cement Example 3 160 410 878 821 1.54 20.4 2.3 0 2.3 0 385 Example 4 160 410 878 821 1.54 20.4 0 2.3 2.3 0 385 Example 5 160 412.3 878 821 1.54 20.4 0 2.3 4.6 0 385

W: Water, C: Cement, S: Fine aggregate, G: Coarse aggregate, THSM: Modified sulfur binder, TP-C: Coarse rubber powder, TP-F: Fine rubber powder, T.C: Tire cord yarn, P: Resin

On the other hand, instead of rubber powder, polyamide fibers of Nykon Materials Co., Ltd., which are polymer fibers (hydrophilic Nykon fibers, fiber diameters of 15 to 35 μm) are cut to about 6 to 12 mm in length and put into a Henschel mixer heated to 80 ° C. After stirring for 5 minutes so that the fiber surface was sufficiently heated, 24 kg of modified sulfur binder powder was added, reacted for a certain period of time (15 minutes), and mixed to prepare an additive for super fast cement with the composition shown in Table 5 below.

EXAMPLES Cement Concrete Composition with Super-fast Cement - When Using Polymer Fibers division Unit amount of material (kg/㎥) Cement composition (kg) W C S G AE product THSM TP-C TP-F T.C. P (resin) crude steel cement Example 6 160 410 878 821 1.54 24 0 0 0 1.0 385 Example 7 160 411 878 821 1.54 24 0 0 0 2.0 385 Example 8 160 413 878 821 1.54 24 0 0 0 4.0 385

W: Water, C: Cement, S: Fine aggregate, G: Coarse aggregate, THSM: Modified sulfur binder, TP-C: Coarse rubber powder, TP-F: Fine rubber powder, T.C: Tire cord yarn, P: Resin

In this case, the melt-modified sulfur binder is attached to the fiber surface and thermally reacts with the fiber, and the hydrophilic group reacts on the fiber surface to enhance the water dispersing effect, thereby maintaining homogeneous dispersibility in the production of super-velocity cement concrete. At this time, the raw material for cement may be introduced and dispersed to prepare a fiber mixture that is uniform in the raw material for cement.

2. Cement per second Confirmation of properties of concrete

(1) Confirmation of surface structure of super-velocity cement concrete

In order to confirm the surface structure of the super-velocity cement concrete prepared according to the present invention, the surface structure of the concrete was confirmed using an electron microscope (JEOL, 6700F) for the surface photograph.

In more detail, FIG. 1 is a surface photograph of the cementitious cement concrete obtained in Comparative Example 1, and FIG. It can be confirmed that a calcite structure is formed by forming the gelled cement raw material and calcium carbonate, and the formation of this structure increases the strength and modulus of cementitious cement concrete, and the microcracks in the cementitious cement concrete. By suppressing the occurrence of water tightness, it improves the water resistance of concrete structures. The size and number of pores were greatly reduced on the concrete surface of Example 1, and it can be confirmed as a result of electron microscope observation that the rubber powder has excellent adhesion to the particle surface (FIG. 1(c)). This is because the additive for super-velocity cement of the present invention exhibits properties of reducing swelling and shrinkage, and furthermore, it can exhibit an effect of reducing the occurrence of voids due to elastic force.

(2) Confirmation of compressive strength of super-velocity cement concrete

In order to check the compressive strength of the super-velocity cement concrete prepared according to the present invention, the compressive strength was measured after 7 days, 14 days, and 28 days after demolding, respectively, and the compressive strength was measured according to KS F 2403.

These test results are summarized in Table 7 below.

Compressive strength (MPa) 4 hours 7 days 14 days 28 days Comparative Example 1 16.80 22.99 28.09 31.77 Comparative Example 2 23.52 38.48 41.11 45.08 Example 1 22.55 36.24 38.60 43.58 Example 2 21.62 36.08 37.19 41.37 Example 3 23.25 38.29 39.16 44.97 Example 4 20.80 29.00 32.78 36.37 Example 5 22.66 33.63 37.38 39.55 Example 6 21.89 35.10 36.02 38.33 Example 7 18.33 26.09 27.08 28.75 Example 8 22.27 36.18 37.33 41.10 Example 9 20.71 30.92 32.11 34.65 Example 10 17.85 26.29 26.99 29.34

Comparative Example 1 In relation to the compressive strength of cementitious cement concrete, the compressive strength of general concrete should be 35 MPa or more. Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and variations are possible within the scope without departing from the technical spirit of the present invention described in the claims. It will be apparent to those of ordinary skill in the art.

Claims (20)

delete delete delete delete delete delete delete delete a powder of an ethoxylated resin obtained through a step of dipping the resin in an ethoxy compound, or a powder of an ethoxylated resin and rubber obtained through a step of dipping the resin in an ethoxy compound; and mixing the modified sulfur binder at a temperature of 80° C. or higher and 200° C. or lower. The method of claim 9, wherein the powder has an average particle size of 0.1 to 5 mm. The method of claim 9, further comprising: heating the powder at a temperature of 80°C or higher and 200°C or lower; and
Step of mixing by inputting the modified sulfur binder
A method for producing an additive for cementing per second comprising a. The method according to claim 11, wherein the heating step is a step of activating the surface by rubbing the powder at a temperature of 80°C or higher and 200°C or lower. The method of claim 11 , wherein the mixing is performed at a temperature higher than or equal to the melting point of the modified sulfur binder. delete 10. The method of claim 9, wherein the step of cooling the mixture obtained by the mixing step to a temperature of -20 ℃ to room temperature; and cutting the cooled additive for cementing per second cement. delete delete delete delete delete

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