KR100901634B1 - Filling grout composition for gravel track rail road and structure of gravel track containing the same - Google Patents

Abstract

A filling grout composition for gravel-track roads and a gravel-track structure thereof are provided to fill the gap between gravel tracks without a bleeding phenomenon or ingredient separation while showing high rapid hardening, intensity, filling and flow properties. A filling grout composition for gravel-track roads comprises: wien mineral with more than 6,000cm^2/g of Blaine specific surface area; Portland cement; lime; gypsum; granulated blast-furnace slag; high-functional water reducing admixture; inorganic thickening agent; polymer powder resin; calsium sulpho aluminate expanding material; anti-shrinkage agent; fluid oil; and silica. The 5-50wt% of wien mineral is added on a weight basis of the Portland cement. The 0.1-5wt% of high-functional water reducing admixture is added on a weight basis of the total filling grout composition. The 0.05-2.0wt% of fluid oil is added on a dry weight basis of the filling grout composition.

Description

Filling grout composition for gravel track rail road and Structure of gravel track containing the same}

The present invention relates to a grout material composition used for the maintenance work of railroad gravel tracks and the railroad gravel track structure injected therein.

The vitalization work of railway gravel tracks is to drastically reduce maintenance efforts of existing ships. Most domestic existing ships are composed of gravel tracks, and a lot of manpower and cost are continuously increasing in maintenance due to high speed, high density, and aging of track components. The main purpose of the vitalization work is to reduce the maintenance effort by basically improving the repair method through the improvement of the track structure.

Track vitalization involves filling gravel voids under railroad ties, and grout material is inevitably required for gravel void filling. The grout material should be characterized by ultra-high hardness, high flow, fillability, high strength, adhesion to aggregate surfaces, and low shrinkage.

Conventional ultra-fast hard grout material is easy to cause material separation or bleeding when high flowability is satisfied, and a retardant must be used to secure working time. However, in order to delay the setting time from several tens of minutes to more than one hour, it is inevitable to use a large amount of the retardant, and even if the working time is secured, the strength expression at 2 hours, 6 hours, and 1 day decreases, and the reproducibility of the setting time delay is reduced. There is a problem with the reality.

Conventional grout materials utilize existing high performance water reducing agents to satisfy high fluidity and fillability, and thickeners and mixtures are used to reduce bleeding, but most of them are bingham fluids or thixotropic fluids with high yield points and low plastic viscosity. There is a fear of voids in the gravel tracks. These voids can eventually lead to a drop in overall strength and a decrease in durability.

In order to improve the adhesion of the aggregate, a method of incorporating an existing polymer or the like has been used, but the existing polymer tends to increase viscosity. In general grout, the increase in viscosity is irrelevant, but in the case of railroads, the increase in viscosity is not suitable because it leads to a decrease in liquidity.

If the mortar in the gravel track contracts, it may eventually cause adhesion surfaces and cracks with the gravel. Therefore, it is important to mix materials with expansion characteristics and low shrinkage characteristics. At the same time, there is a possibility of a loss of strength, so be careful.

The present invention improves the existing condensation delay method and the flow characteristics of the grout material to solve the above problems, and by developing a construction method suitable for the flow characteristics, work time in construction using the grout material for railway gravel track The purpose is to secure safe and efficient pouring work and vitalize the railroad.

The invention Blaine specific surface area 6,000cm ² / g or more Irwin mineral, Portland cement, gypsum, lime, blast furnace slag, superplasticizer, inorganic thickening agents, polymeric resin powder, calcium sulfo-aluminate (calsium sulpho aluminate, CSA) type expandable material, Provided is a fill grout material composition comprising a shrinkage reducing agent, a fluid retainer, and silica sand.

In another aspect, the present invention is a geotextile laid on the upper surface of the subgrade layer 10, a grout injection layer formed on the geotextile, a sleeper 50 laid on the new bed layer, and the rail fastening device on the sleeper It consists of a track installed by; The grout injecting layer provides a railway gravel track structure, characterized in that the filling grout composition is injected into the pores of the gravel filled in the internal space in which the geotextiles are laid.

The grout material composition according to an embodiment of the present invention has a physiological fluid, ultrafast hardness, high flow rate, fillability, high strength, adhesion to the aggregate surface, low shrinkage characteristics, without material separation or bleeding It is possible to fill between the gravel tracks and, after hardening, the compressive strength is expressed in a short time, so it can be suitably used for the vitalization work of the gravel tracks on railways. In addition, by injecting in the gravel track structure by using the pipe injection method injection method in the gravel track can significantly reduce the maintenance efforts of the existing ship.

In order to revitalize the maintenance of railway gravel tracks, the cost of gravel track maintenance, which accounts for the largest portion of the costs for rail track maintenance, is to be saved. For this purpose, grout material is required to fill and solidify the mortar between the pores on the gravel. Since the grout material has to be worked within a certain time due to the characteristics of the work, the grout material should have characteristics of ultra-high hardness, high flow rate, fillability, and high strength. In addition, the method of injecting the grout material is important because the image must be concreted by penetrating between the gravel.

Hereinafter, with reference to the accompanying drawings will be described a specific configuration and effect of the gravel track filling composition for gravel track and gravel track structure using the same.

First, the gravel track structure according to the present invention will be described.

1 is a schematic perspective view showing a gravel track structure according to an embodiment of the present invention. As shown in the figure, the gravel orbit structure is a subgrade layer 10, the ground fiber 10 laid one or more layers from below, the grout injection layer 21 is formed by injecting the filling grout material composition according to the present invention , Sleeper 50, rail fastening device 60 and the track 70. In FIG. 1, reference numeral 40 denotes an asphalt surface layer 40 that may be additionally formed if necessary for preventing surface contamination such as ease of drainage and dust generation on the grout injection layer 21. The asphalt surface layer 40 may not be formed. Non-woven fabric, geotextile, geomembrane, etc. may be used as the geotextile 30, and is laid on the upper surface of the subgrade layer 10, the bottom surface is in contact with the upper surface of the subgrade layer 10, the left and right both ends of the bottom surface That is, the cross section is laid in a? -Shape so as to have a side surface perpendicular to the direction. In the drawing, reference numeral 22 denotes a side drawing layer 22.

In one embodiment of the present invention, the grout injection conductive layer 21 has a structure in which the filling grout material composition according to the present invention described later is injected and filled into the pores of the gravel gravel. The filling grout material composition according to the present invention, as described below, is composed of a form of a sintering fluid capable of securing a working time while being super fast. Therefore, the filling grout material composition according to the present invention can be injected into the pores of the phase gravel using a pipe in the field. Figure 2 is a schematic diagram showing the injection of the filling grout material composition according to the present invention by inserting the pipe 23 in the phase gravel. As such, when the pipe 23 is inserted and injected, a problem that the filling property is deteriorated due to friction between the filling grout material composition and the aggregate and the injection height can be prevented. However, the present invention is not limited thereto, and the filling grout material composition may be injected into the pores of the island gravel in a natural dropping manner.

Next, the filling grout material composition according to the present invention will be described.

Filling grout material composition according to an embodiment of the present invention is a Bran specific surface area of more than 6,000 cm ² / g of Irwin mineral, portland cement, gypsum and lime, blast furnace slag powder, high performance water-reducing agent, inorganic thickener, polymer powder resin, CSA-based expander, Shrinkage reducing agents, flow retaining agents and silica sand.

Although the amount of subatomic minerals used in the present invention varies depending on the required strength, it is preferably 5 to 50% by weight based on the Portland cement. It is because the effect is small when it is less than 5 weight%, and even if it exceeds 50 weight%, the improvement of the effect cannot be expected.

As gypsum, anhydrous gypsum, hemihydrate gypsum and dihydrate gypsum can be used. Among them, anhydrous gypsum is preferable in view of fastness. As for gypsum use amount, 1-20 weight% with respect to Irwin mineral is preferable at the point of fastness.

Lime lime can be used hydrated lime, quicklime, and among them, hydrated lime is preferred, and the amount of lime used is preferably 1 to 20% by weight based on Irwin minerals.

In the present invention, in order to reduce the amount of water used and increase the fluidity, admixtures such as a high performance water reducing agent, a high performance AE water reducing agent, and a fluidizing agent which are generally used may be added. Melamine type or naphthalene type is preferable, but polycarboxylic acid type may be used. The amount of the admixture is suitably 0.1 to 5% by weight based on the total grout material composition.

The proper amount of fluid retaining agent is 0.05 to 2.0% by weight based on the powder of the grout material. These powders may be used alone or in combination, and may be used in combination with superhard cement, or may be dissolved in an aqueous solution (mixed water) and used.

CSA-based expander refers to a calcium sulpho aluminate system, which provides expansion performance without adversely affecting the mortar's physical properties, thereby inhibiting dry shrinkage due to the external environment. To prevent cracking and improve adhesion strength. 8-12% by weight is appropriate for Portland cement.

In addition, the shrinkage reducing agent may use 0.5 to 1% by weight of the alkylene ether organic based on the portland cement in preparation for long-term shrinkage.

The polymer powder resin used in the present invention is preferably an acrylic powder resin having acid resistance, and may be used in a powder state during powder mixing as a redispersable polymer powder for a premixed mortar composition. It is the molecular weight of the acrylic resin powder is not particularly limited, and generally from 10 ⁵ to 10 ^6. Moreover, it is preferable that the particle diameter of powder resin is 1 micrometer or less. When properly mixed with the cement component, the resin film is formed between the cement hydrate and the adhesion surface between the aggregates, thereby filling the voids, thereby increasing the compactness and the adhesion strength.

Inorganic thickeners used in the present invention have a needle-like structure such as fibers, and the needle has an electrostatic form as shown in FIG. 3. When the grout material composition according to the embodiment of the present invention including an inorganic thickener and a high-performance reducing agent is mixed with mixed water and injected into a gravel track, the high-performance reducing agent disperses the cement-based particles, and the inorganic thickener in between If the shear stress is not applied, the needle-like thickener is oriented irregularly, and the materials are not homogeneously separated, but are homogeneously mixed. However, when the force is applied, the thickening material is oriented and flows easily, giving high fluidity characteristics. In addition, since it has static electricity, fluidity is further improved. 4 is a schematic diagram showing an inorganic thickener when no force is applied and when a force is applied.

On the other hand, when using the conventional organic thickener, the viscosity is improved to prevent material separation, but as shown in Figure 5 has a disadvantage that it does not fill well in the gravel track because the viscosity remains as improved.

Therefore, the inorganic thickener used in the present invention improves the flow characteristics in addition to the viscosity improvement of the grout material composition, so that the yield point is 0 to 10 Pa, and the plastic viscosity is 1.0 to 5.0 Pa · s. As a result, the grout material composition of the present invention is filled to the corners of the gravel track and has a physicoplastic fluidity in which material separation is suppressed.

The blast furnace slag fine powder used in the present invention was used by pulverizing the particle size distribution as shown in FIG. The blast furnace slag powder was ground into particles having a diameter of about 6 μm. As shown in FIG. 7, when the average particle size of cement is assumed to be 16 μm and the cement particles are round particles, the size of particles that can enter the pores is about 6 μm. Therefore, the blast furnace slag fine powder is pulverized to about 6㎛ to fill the gap between the cement particles to increase the filling rate, densified to improve the physical properties.

On the other hand, the railroad grouting material should have very excellent fluidity due to its characteristics. It is also important to use organic admixtures such as high-performance susceptors to impart the flow characteristics, but since the particle size of the aggregate also affects, the filling rate is higher than 95% by selecting No. 3, No. 4 and No. 5, that is, high fluidity. Aggregate blending ratio was found. Figure 8 shows the correlation between the mixing ratio and filling rate for each aggregate aggregate.

The grout material composition of the present invention provides a construction that can pass through the railroad after 2 hours after construction is completed because the compressive strength of the cured body of 2 hours after kneading is expressed over 20 MPa. can do.

Hereinafter, an embodiment of the present invention is shown below, but the scope of the present invention is not limited to this embodiment.

[ Example  One]

The composition ratio of the grout material Example composition of this invention is shown in Table 1. The water powder ratio was fixed at 24%. After the powder was mixed with a predetermined amount of mixed water for about 2 minutes to prepare a paste, the rheological constants of yield value and plastic viscosity were also measured using rheometer for flow characteristics immediately after mixing and after 20 minutes.

division cement Subatomic mineral gypsum Slaked lime Inflating material Blast Furnace Slag Powder Inorganic thickeners Polymer resin High performance water reducer Shrinkage reducing agent Quartz sand # 3 #4 # 5 Example 1 22 15 5 1.5 8 2 2.5 2.5 One 0.5 11 7 22 Example 2 22 16 3.5 2 8 2 2.5 1.5 2 0.5 Example 3 20 16 3 2 8 2 3.5 3.5 2 0.5 Example 4 20 17 5 1.5 8 2 2.5 2.5 One 0.5 Comparative Example 1 53 4 3 Comparative Example 2 54 4 2

9 is a result of measuring the flow characteristics, the yield value and the plastic viscosity by using a rheometer in Comparative Examples and Examples. In addition, the yield value and the plastic viscosity measured value which are rheological constants are shown in Table 2.

As can be seen in FIG. 9, the embodiment of the present invention is a sintered fluid that is secured at high speed and has a low working time, so that the yield value is low, so that the material can be filled in the gravel orbit, and the plastic viscosity does not cause material separation after filling. .

division Yield Value (Pa) Plastic viscosity (Pas) Right after mixing 20 minutes later Right after mixing 20 minutes later Example 1 0.5 0.7 1.5 2.3 Example 2 0.4 0.8 1.8 2.2 Comparative Example 1 18 - 5.3 - Comparative Example 2 15 - 6.2 -

[ Example  2]

The grout material of the present invention was prepared by mixing the powder with a predetermined amount of water for about 2 minutes at a water powder ratio of 24%. After about 20 minutes, the grout material prepared in Example 1 and Comparative Example 1 was filled with gravel in a specimen mold having a diameter of 15 cm x height of 30 cm, and then injected into a natural drop method. After curing in Fig. 10 is shown a photograph of the concrete fracture surface.

Of the present invention The concrete fracture surface (a) of the grout material Example 1, which is a sintered fluid, shows that the grout material is present in a completely filled state between the gravel. In the case of Comparative Example 1, it can be seen that empty voids (in the solid line) exist between the gravel (b) and that material separation occurs as shown in (c).

[ Example  3]

Table 3 is the results of the physical properties of the grout material Example 1 and Comparative Example 1 of the present invention prepared by the manufacturing method as described above. For reference, Table 4 lists the performance criteria of grout materials needed for the gravel track vitalization work for the grout material required for railroad work.

Evaluation item Example 1 Comparative Example 1 Remarks and Test Methods Fluidity (flow time) Immediately after mixing 6.0 seconds 10 sec J14 log descent time 20 minutes after mixing 8.0 seconds Not measurable Compressive strength 2 hours 22 MPa Not measurable 28 days 51 MPa 54 MPa Change of concrete length 2.5 x 10 ^-1 6.5x10 ^-7 Durability Good Bad Freeze thawing, chemical resistance

Evaluation item Performance requirements Remarks and Test Methods Fluidity (flow time) Immediately after mixing Within 8 ± 2 seconds J14 log descent time 20 minutes after mixing Within 8 ± 2 seconds Compressive strength 2 hours 10 MPa or more 28 days 40 MPa or more Change of concrete length Within 1x10 ^-4 ± 3 Low shrinkage Durability Good Freeze thawing, chemical resistance

Various physical properties were satisfied with the required performance of the filling grout material for railway gravel tracks, and the durability characteristics were also satisfied with the tests for freeze-thawing resistance and chemical resistance, especially acid rain.

[ Example  4]

 Through the field test construction of the grout material of the present invention, the pipe injection method was adopted to improve the site pouring method. This improvement was able to improve the field workability characteristics.

As a result of injecting Example 1 and collecting the specimen after curing, it was confirmed that it was completely filled.

1 is a schematic perspective view showing a gravel track structure according to an embodiment of the present invention.

Figure 2 is a schematic diagram showing the injection of the filling grout material composition according to an embodiment of the present invention by inserting the pipe 23 in the phase gravel.

Figure 3 is a schematic diagram showing the electrostatic form of the inorganic thickener used in one embodiment of the present invention.

Figure 4 is a schematic diagram showing the inorganic thickener when not applying a force and the inorganic thickener used in one embodiment of the present invention.

5 is a schematic diagram showing a conventional organic thickener.

6 is a graph showing the particle size distribution of blast furnace slag fine powder.

7 is a schematic diagram showing the blast furnace slag fine powder form between cement particles.

8 is a graph showing the correlation between the blending ratio and the filling rate for silica sand.

9 is a graph showing the flow characteristics of the Examples and Comparative Examples of the present invention.

It is a photograph which shows the fracture surface of the charged state in gravel track | orbit.

Claims (11)

Irwin minerals with a specific surface area of 6,000 cm ² / g or more, Portland cement, Gypsum, Lime, Blast furnace slag powder, High performance water reducing agent, Inorganic thickener, Polymer powder resin, Calcium sulpho aluminate (CSA) type expander, Shrinkage reducing agent Filling grout material composition comprising a flow retaining agent and silica sand.  The filling grout material composition of claim 1, wherein the sub-mineral mineral is 5-50% by weight based on the weight of the Portland cement. The filling grout material composition of claim 1, wherein the high performance water reducing agent is 0.1 to 5% by weight based on the total weight of the grout material composition. The filling grout material composition of claim 1, wherein the fluid retaining agent is 0.05 to 2.0% by weight of the dry grout material composition. The filling grout material composition of claim 1, wherein the calcium sulfo aluminate-based expander is 8-12 wt% based on the weight of the Portland cement. The filling grout material composition of claim 1, wherein the shrinkage reducing agent is 0.5 to 1% by weight based on the weight of the Portland cement. The filling grout material composition of claim 1, wherein the inorganic thickener uses magnesium aluminosilicate mineral. The filling grout material composition according to claim 1, wherein the blast furnace slag fine powder has a diameter of 5-6 µm. The filling grout material composition according to claim 1, wherein the yield value is 0 to 10 Pa and the firing viscosity is 1.0 to 5.0 Pa.s. The filling grout material composition according to claim 1, wherein the cured product compressive strength after 20 minutes of pot life is maintained at 20 MPa or more. Geotextiles (30) laid on the upper surface of the subgrade layer (10), And a grout injection layer 21 formed on the geotextile 30; The sleeper 50 is placed in the new icon layer 21, It consists of a track (70) installed by the rail fastening device (60) on the sleeper (50); The grout injection conductive layer 21 is formed by injecting the filling grout material composition according to any one of claims 1 to 10 in the pores of the gravel filled in the internal space in which the geotextile 30 is laid. Railway gravel track structure.

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