KR20200054573A - Non-Shrinkage Grout Composition Using Ground Fly Ash - Google Patents

Abstract

The present invention relates to a non-shrink activated particulate grout composition using ground fly ash as an admixture, and more specifically, to a non-shrink activated particulate grout composition using ground fly ash as an admixture, characterized in that fly ash generated in a thermal power plant is ground to increase particle energy and the ground fly ash is applied as an admixture for non-shrink grout, and thus, the non-shrink activated particulate grout composition has improved fluidity and durability, can implement strength, and can replace cement. One preferred embodiment of the present invention is achieved by mixing 35-45 parts by weight of water, 50-65 parts by weight of fine aggregates, 0.5-1 parts by weight of a water reducing agent, 4-6 parts by weight of calcium sulfoaluminate, and 0.5-2 parts by weight of ethylene-vinyl acetate with respect to 100 parts by weight of a mixture replacing 10-20 wt% of the ground fly ash in Portland cement.

Description

Active powder non-shrinkage grout composition using ground fly ash as an admixture {Non-Shrinkage Grout Composition Using Ground Fly Ash}

The present invention relates to an active powder non-shrinkable grout composition in which a pulverized fly ash is applied as a miscible material, and more specifically, by pulverizing fly ash generated in a thermal power plant (GFA; Ground Fly Ash) to increase particle energy, and then to increase the particle energy. The present invention relates to an active powder non-shrinkable grout composition in which a pulverized fly ash capable of replacing cement is applied as an admixture with improved fluidity, durability, and strength.

 Recently, the size of the grout market is gradually expanding due to the aging and new installation of facilities. The size of the grout market in Korea is over 700 billion won, and the material market is also over 100 billion won.

The grout is used for the foundation of machinery or the support and joints of bridges, emergency repairs of various structures, etc. And it is a cement-based material for dispersing and transferring the load of the upper part to the lower part by integrating the upper structure and the lower structure by completely filling the gaps between the lower concrete structures. In addition, in order to improve the properties of the soil before excavating the ground, it is mainly used in cases where high strength is required by curing in a short time, such as by grouting in the ground or in the ground. Therefore, conditions such as improved workability, reduced shrinkage, high-early strength, and adjustment of the setting time must be satisfied.

In general, the non-constricted grout used to mix blast furnace slag, fly ash, silica fume, desulfurized gypsum, and bentonite to satisfy the above conditions, but it is difficult to exhibit sufficient effects such as improving fluidity, improving durability and expressing strength. there was.

As a background technology of the present invention, there is a patent registration No. 1709239 "Eco-friendly inorganic grout composition for ground water using industrial by-products" (Patent Document 1). In the background art, 'calcium aluminate amorphous powder 50 ~ 90 wt%, sodium carbonate 4 ~ 30 wt%, anhydrous gypsum 0.1 ~ 20 wt%, inorganic mineral fastener 5 ~ 20 wt%, fly ash 15 ~ 50 wt% A common A suspension prepared by mixing 40% to 65% by weight of water in a dry powder of 5% for 30 minutes; Rapid fly B suspension prepared by mixing 40 to 60% by weight of water in a dry powder containing 35 to 45% by weight of purified fly ash and 5 to 20% by weight of cement; And purified fly ash 35 ~ 45% by weight, cement 5 ~ 20% by weight, surfactant 0.01 ~ 0.5% by weight, mixed with dry powder for 5 ~ 30 minutes, 40 ~ 59% by weight of water We propose an eco-friendly inorganic grout composition for subsurface water using industrial byproducts, characterized in that 2 shots or 1.5 shots are possible through a two-liquid three-earth stirrer that can be applied to the suspension draw-in grout method.

However, although the background technology is to mix fly ash, there is a problem in that the effect of improving fluidity, improving durability, and expressing strength is not exhibited because the powder is not determined.

Patent registration No. 1709239 "Eco-friendly inorganic grout composition for ground water using industrial by-products"

The present invention is to solve the above problems, by crushing the fly ash generated in the thermal power plant (GFA; Ground Fly Ash) to increase the particle energy and then applied as a mixed material for a non-shrink grout to improve fluidity, improve durability And crushing fly ash that is economical as well as economical by solving the problem of environmental pollution and efficient use of resources, and high cost of existing solidified materials due to cement replacement by allowing cement to be replaced with expression of strength and It is an object to provide an active powder non-shrink grout composition applied as a miscible material.

The present invention is 100 parts by weight of a mixture of 10-20% by weight of fly ash crushed in Portland cement, water 35-45 parts by weight, fine aggregate 50-65 parts by weight, water reducing agent 0.5-1 part by weight, calcium sulfo-aluminate It is intended to provide an active powder non-shrink grout composition to which 4 to 6 parts by weight of ethylene-vinyl acetate is mixed with 0.5 to 2 parts by weight of pulverized fly ash as a mixture.

In addition, the fly ash is intended to provide an active powder non-shrink grout composition to which a pulverized fly ash, which is pulverized to 6500 to 7500 cm ² / g, is used as an admixture.

In addition, the water reducing agent is to provide an active powder non-shrink grout composition applying a pulverized fly ash as an admixture, which is any one of a lignin sulfonate-based, naphthaline sulfonate-based, melamine sulfonate-based, and polycarboxylic acid salt-based. .

The active powder non-shrink grout composition to which the pulverized fly ash of the present invention is applied as an admixture is pulverized by pulverizing the fly ash generated in a thermal power plant (GFA; Ground Fly Ash) to increase the particle energy and then applied as a admixture for non-shrink grout. It is possible to replace cement with improvement, durability improvement, and strength, effectively solving environmental pollution problems, efficient use of resources, and high cost of existing solidified materials due to cement replacement. It has a very useful effect.

The following drawings attached in the present specification are intended to illustrate preferred embodiments of the present invention, and serve to further understand the technical idea of the present invention together with the detailed description of the present invention, so the present invention is only described in the accompanying drawings. It should not be interpreted as limited.
1 is a diagram showing a flow experiment.
2 is a graph showing the measured flow time according to the GFA and RFA content.
Figure 3 is a graph showing the results of the condensation test of the shrinkage grout composition according to the GFA and RFA content.
Figure 4 is a photograph of the bleeding experiment of the non-contraction grout composition.
Figure 5 is a graph showing the length change according to the curing date of the non-shrinkable grout composition.
6 is a graph showing the results of the compressive strength test according to the curing date of the non-shrinkable grout composition in the order of 1 day, 3 days, and 7 days.

The present invention will be described in detail below with reference to the embodiments presented in the accompanying drawings, but the presented embodiments are illustrative for a clear understanding of the present invention and the invention is not limited thereto.

Hereinafter, a detailed description of the technical configuration of the present invention according to a preferred embodiment.

The present invention is 100 parts by weight of a mixture of 10 to 20% by weight of fly ash crushed in Portland cement, 50 to 65 parts by weight of fine aggregate, 4 to 6 parts by weight of calcium sulfo-aluminate, 0.5 to 2 parts by weight of EVA, water It is made by mixing 35 to 45 parts by weight and 0.5 to 1 part by weight of a water reducing agent.

In the present invention, fly ash was applied to the non-constricted grout to express the strength of the grout and to improve durability.

Fly ash is used as a substitute for OPC for the purpose of promoting pozzolanic reaction and enhancing durability, and it is replaced by less than 10% by weight of OPC, so that it is not good in fluidity when mixed, and has effects such as expressing compressive strength, improving durability, or reducing setting time. Does not appear, and it is preferable to mix 10 to 20% by weight in OPC because the strength is lowered when the mixture is replaced by exceeding 20% by weight.

In the present invention, after the fly ash is crushed to increase the particle energy, it is used as an admixture for a non-shrink grout, and the pulverization has a uniform powderiness and is preferably crushed to 6500 to 7500 cm ² / g. The fly ash has a spherical shape, thereby exerting a ball bearing effect and contributing to an increase in the fluidity of the paste.

When crushing to less than 6500 cm ² / g, the hydration is slow, so the early strength does not appear high, and when it exceeds 7500 cm ² / g, the calorific value increases, so it is preferable to crush the fly ash to 6500 to 7500 cm ² / g.

When the coal ash is burned in a thermal power plant or the like, the fly ash can be used by cooling and solidifying the floating non-combustible part in a molten state. The fly ash may have a density of 1.95 g / cm 3 or more and a specific surface area of 30,000 g / cm 3 or more conforming to the KS L 5405 standard. In addition, since fly ash is a spherical particle with a smooth surface, it acts as a ball bearing to improve concrete workability, that is, to improve fluidity, by slowly mixing at room temperature with calcium hydroxide dissolved in water to generate an insoluble compound, thereby reducing heat of hydration, long-term strength, and Water tightness can be increased.

Water is mixed with 35 to 45 parts by weight based on 100 parts by weight of the pulverized fly ash mixture, which partially replaces the OPC and the OPC, and the water content can be selectively adjusted to an optimal range in terms of strength and fluidity.

The fine aggregate is preferably mixed with 50 to 65 parts by weight based on 100 parts by weight of the crushed fly ash mixture partially replacing the OPC and the OPC.

Fine aggregate can be used for concrete, generally known as KS F 2526, particle size of 0.15 to 5.0 mm, absolute dry density of 2.5 g / cm 3 or more, absorption of 3% or less, stability of 10% or less can be used. In terms of flowability and material separation reduction, it is reasonable to limit to the above content range.

The water reducing agent is preferably mixed with 0.5 to 1 part by weight based on 100 parts by weight of the pulverized fly ash mixture partially replacing the OPC and OPC.

Water-reducing agents can use a variety of known water-reducing agents such as lignin sulfonate-based, naphthaline sulfonate-based, melamine sulfonate-based, and polycarboxylic acid salt-based, and include any chemical structure to reduce the dispersibility and unit quantity of cement. Can be. For example, it may be a PC-based high performance AE water reducing agent having a structure in which a nonionic surfactant such as ethylene oxide is crosslinked to a polycarboxylic acid water chain.

Typically, when lignin sulfonic acid is added, it is ionized with sulfonic acid anion and calcium cation in water to show strong anionic activity, and flows water and air between particles in agglomerated state to impart fluidity to cement.

If it is composed of 0.5 parts by weight or less, the particles of cement cannot be effectively dispersed, and when it is composed of 1 part by weight or more, it is preferable to be composed of 0.5 to 1 part by weight, because economic efficiency and the effect compared to the composition ratio are not properly expressed. Do.

AE water reducing agent generally refers to a substance that adsorbs on the interface of two or more phases or other substances to significantly change the properties of the interface, and the basic molecular structure is two identical structures, namely hydrophobic groups that are not easily soluble in water and soluble in water. It is composed of hydrophilic groups and classified into anionic, cationic and nonionic based on the electrical properties of hydrophilic ions in aqueous solution.

The anionic AE water reducing agent comprises most of the commercially available AE water reducing agents, the main chemical components of which are resin salts, sulfate esters, and sulfonates, and the cationic AE water reducing agent is a hydrophilic group having a cation and is not used as an AE agent. In addition, the nonionic AE water reducing agent does not dissociate into ions in water, but the ether itself and the ester system are used as the molecule itself acts as a surfactant. The AE water reducing agent is a admixture capable of reducing the unit quantity by dispersing cement particles in concrete or improving the workability while entraining microbubbles in concrete while reducing the unit quantity by dispersion effect. AE water reducing agent is classified into standard type, delayed type, and accelerated type according to the rate of condensation and initial curing of concrete, and depending on its chemical composition, lignin sulfonate, alkylarylsulfonic acid, polyoxyethylene, alkylaryl ether, Oxycarbonic acid-based, melaminesulfonic acid-based, and fullical-carboxylic acid-based may be used.

High-performance water-reducing agent refers to admixture that can improve the function of a general water-reducing agent, effectively disperse cement particles, and use it at a high addition rate without adversely affecting condensation delay, excessive air entrainment, and strength reduction.

Calcium sulfo-aluminate (CSA) is mixed to improve drying shrinkage prevention and early strength properties, based on 100 parts by weight of a pulverized fly ash mixture partially replacing the OPC and OPC, 4 to 6 weights It is preferred to mix by part.

A representative mineral of calcium sulfo aluminate (CSA) -based cement is ettringite, which is a crystal produced by the reaction of limestone, gypsum, and alum. During the production process of CSA-based cement, 85% of ethringite is formed at the beginning of production, so it has long-term stability.

The use of CSA cement, whether mortar, concrete or composite cement, accelerates the setting time of the product, increases the initial strength, and does not affect the late strength. Depending on the addition amount, shrinkage and expansion performances can also be repaired. Due to the excellent performance of these CSA cements, it is often used in products requiring fast setting time and high initial strength.

Therefore, when mixing to less than 4 parts by weight, it is preferable to mix 4 to 6 parts by weight because the super strength is not properly expressed, and when it exceeds 6 parts by weight, the economic efficiency is poor.

Ethylene vinyl acetate (EVA; ethylene-vinyl acetate) is mixed to improve bleeding prevention and material separation resistance, and based on 100 parts by weight of the pulverized fly ash mixture partially replacing the OPC and OPC, 0.5 to 2 parts by weight It is preferred to mix.

When mixing to less than 0.5 parts by weight, the effect of preventing bleeding and the like does not appear, and when mixing more than 2 parts by weight, compatibility and economic efficiency are lowered, so it is preferable to mix 0.5 to 2 parts by weight.

The fly ash was pulverized to a level of 7,000 cm ² / g, and the crushed and unpulverized fly ash was replaced with OPC (usually Portland cement) at a ratio of 10, 20, and 30% by weight, and a mixture was prepared and compared with each other.

As a grout compounding material, EVA and a water reducing agent were added to improve bleeding prevention and material separation resistance, and CSA was added to prevent dry shrinkage and improve early strength properties.

In the flow and flow time tests for the analysis evaluation of workability, results satisfying the performance standards were obtained except for the blending ratio to which 30% by weight of fly ash was not pulverized.

In the setting and bleeding tests, there was no significant difference in the results of the pulverized fly ash and the non-pulverized fly ash, but the higher the fly ash content, the more the tendency for the setting time to decrease.

As for the rate of change in length, the grout without addition of the admixture contracted at the largest rate, but it was confirmed that the change rate was very slight at 0.0005%. The two grout compositions to which pulverized fly ash was applied at 10 and 20% by weight exceeded the grout compressive strength level without addition of admixtures or secured a high strength value as the age increased in the compressive strength characteristics.

Therefore, in the present invention, the fly ash generated in the thermal power plant was pulverized (hereinafter referred to as GFA (Ground Fly Ash)) to increase the particle energy, and then applied as a non-shrinkable grout mixture. Ash)) to make an optimal non-contraction grout composition.

<Experimental Example>

In the present invention, according to KS F 4044, the flow time, flow, setting time, bleeding rate, length change rate and compressive strength of a non-constricted grout were tested.

OPC (ordinary portland cement), calcium sulfo-aluminate (hereinafter referred to as CSA), and fly ash (GFA or RFA) were used as the main raw materials for the active powder non-constricted grout. Fine aggregate was used as No. 6, and water reducing agent and ethylene-vinyl acetate (EVA) were used as additives.

CSA was used to promote curing of the grout, to increase initial strength, and to prevent drying shrinkage during curing. The active powder was pulverized to a level of 5,000 cm ² / g using a vibration mill, and GFA and RFA were used for the purpose of promoting pozzolanic reaction and enhancing durability. Water-soluble polymer EVA and liquid water-reducing agent were used as additives for the purpose of reducing the amount of cement unit, improving fluidity, preventing bleeding, improving filling properties and resisting material separation.

Table 1 is the formulation design conditions of the shrinkage grout using GFA. GFA and RFA were used to replace the cement to prepare a mixture using 10%, 20% and 30% by weight.

Based on 100 parts by weight of the mixture, fine aggregate was 61 parts by weight compared to powder, CSA was additionally mixed by 5 parts by weight, EVA for improving fluidity and reducing unit quantity, etc., 1 part by weight of EVA, and 0.8 parts by weight of water reducing agent were mixed.

No.
Mixture (% by weight) SANDM
CSA
EVA
Water reducing agent
Mixed Water OPC GFA RFA Ref 100 - - 61 5 One 0.8 39 G1 90 10 - G2 80 20 - G3 70 30 - G4 90 - 10 G5 80 - 20 G6 70 - 30

Before performing the shrinkage grout dough using pulverized fly ash (GFA), the powders and fine aggregates that had been improved were thoroughly mixed. Subsequently, after sufficiently mixing the mixed water and the water reducing agent, a test specimen was prepared in a laboratory having a temperature of 20 ± 2 and a humidity of 45 ± 20% according to the KS F 4044 standard.

1. Slurry characteristics

Table 2 shows flow measurement values according to the content of pulverized fly ash (GFA) and finely pulverized fly ash (RFA).

1 is a diagram showing a flow experiment.

After completing the mixing, the grout composition was filled in a flow cone located in the center on the flow table, and the surface was evened and the flow cone was immediately removed to remove the flow cone and proceed with the experiment. The test was conducted twice, and the average value was used as the measured value.

In all grout formulation conditions, as shown in FIG. 1 (a), flow values exceeding the maximum diameter of the flow table were obtained without material separation, which was a result of satisfying the criterion for non-shrink grout performance (225 mm or more).

This was estimated by the effect of fly ash ball bearing, the optimum mixing ratio without material separation phenomenon, that is, the effect of the proper amount of mixed water ratio and additives. However, in the flow test, it was difficult to analyze the fluidity characteristics according to the content of GFA and RFA, so a flow time experiment that facilitated the analysis of the flow characteristics was additionally performed.

Flow of Non-Shrinkage Grout (Flow Table Method) No. Ref G1 G2 G3 G4 G5 G6 Flow 255 over

Figure 2 shows the measured flow time according to the GFA and RFA content.

The flow test funnel was adjusted to a height adjustment gauge according to the suggested specifications, and the flow time test was conducted within 1 minute after the completion of grout mixing. As in the flow table test, the average value of the two tests was used as the measured value.

Ref obtained a measurement value of 44 seconds through a flow time experiment, which satisfies the criterion for non-shrink grout performance (within 60 seconds). The mixing time of the mixing conditions G1, G2, G3 and G4 did not show a big difference compared to the flowing time of Ref.

The compounding condition G5 was increased by 10 seconds compared to the Ref flow time. G6 obtained a measurement value of 71 seconds, which increased by 27 seconds compared to the Ref flow time, and was confirmed to exceed the flow test performance criterion.

The results of the flow tests according to the content of GFA and RFA showed a tendency to contradict each other. In general, fly ash has excellent adhesion to chemical admixtures. Accordingly, when using fly ash, it does not contribute to improving the flow characteristics of cement, so workability tends to decrease. In particular, in the present invention, the content of the chemical admixture was very high compared to the general mortar (0.1 to 0.5%).

In the present invention, the fly ash content increased (G4 ~ G6), the flow time increased, that is, it showed a result that the workability decreases. However, G1 ~ G3 did not have a significant difference in the flow time, because the volume of the pulverized fly ash increased relative to that of the finely pulverized fly ash, reducing the cement content in the grout of the same volume, and thus, the hydration reaction The amount of cement will decrease.

2. Slurry curing properties

Condensation test results of Non-Shrinkage Grout according to GFA and RFA contents are shown in FIG. 3.

In the grout setting test, the time when the super setting needle was stopped at 1 mm from the top surface of the base plate was used as the initial setting time, and the measured values were recorded at 5 minute intervals. In addition, the time when the needle for termination was no longer leaving a trace on the surface of the grout was used as the termination time, and measurement values were recorded at 15 minute intervals.

It was confirmed that the setting time satisfies the non-shrink grout performance criterion (more than 1 hr at the beginning and within 10 hr at the end) under all mixing conditions. As the setting time of GFA and RFA increased, a phenomenon in which the initial result and the termination time slightly decreased was observed. The setting time according to the content of GFA and RFA did not show a big difference, but the RFA mixed grout exhibited a characteristic that the initialization and termination time were slightly reduced compared to when mixing GFA. This is a result of reducing the amount of cement by introducing a large amount of the chemical admixture mentioned above and increasing the fly ash content in the same volume grout.

Figure 4 is a photograph of the bleeding experiment of the non-contraction grout composition.

A polyethylene cylinder having a diameter of about 50 mm and a height of 500 mm or more was used as the test container. After filling the mixed grout composition up to about 200 mm according to the mixing conditions, the entrance was sealed with paraflim to prevent evaporation of the bleeding water.

After 3 hours from the start of the measurement, water generated due to bleeding should be taken out to measure the capacity, but bleeding did not occur at all in all mixing conditions.

3. Length change test and compressive strength

For the length change test and the compressive strength test, a test specimen was prepared under the mixing conditions of Table 1 using a mold for molding a 40x40x160mm specimen.

The test specimen for the change in length and compressive strength was demolded after 24 hours in a thermo-hygrostat at 20 ± 2 ℃ and 60% humidity after molding the specimen. Thereafter, the test specimen for length change was cured in a thermo-hygrostat after measurement, and the test specimen for compressive strength was cured in a constant temperature water bath at a temperature of 20 ± 3 ℃.

Figure 5 is a graph showing the length change according to the curing date of the non-shrinkable grout composition.

As can be seen in Figure 5, the 14-day curing specimens are Ref = 143㎛, G1 = 131㎛, G2 = 126㎛, G3 = 100㎛, G4 = 130㎛, G5 = 130㎛ and G6 = 98㎛ level Shrinked. Accordingly, as the content of GFA and RFA increased, the change rate of length was observed to decrease, and the maximum change rate of Ref was also found to be only 0.0005%.

This confirmed that a very good result was derived when compared with the change in length according to the curing date of a typical mortar.

As such, the reason why the rate of change in length is very low is that cement affecting the change in length is reduced due to the replacement of fly ash, and due to the expansion effect caused by the CSA hydration, cement drying shrinkage mostly compensates for the length change of the grout specimen.

6 is a graph showing the results of the compressive strength test according to the curing date of the non-shrinking grout composition in the order of 1 day, 3 days, and 7 days.

The formulation conditions G3 and G6 were found to be mostly below the compressive strength performance criteria.

It was judged that the fly ash was excessively added as a cement substitute admixture, so that the grout did not develop early strength. When the fly ash was applied as an admixture, the compressive strength gradually decreased as the content increased, and the grout with RFA showed lower strength than the grout with Ref and GFA at all ages.

However, the formulation conditions G1 grout showed a compressive strength similar to Ref from the 3rd day of age, and it was confirmed from the 7th day of age that the two formulation conditions of G1 and G2 showed similar or higher strength than Ref. This was judged to be the influence of the intensity expression due to the pozzolanic reaction of fly ash, because GFA caused the pozzolanic reaction as shown in Equation 1 below to be relatively active with RFA.

--(식 1)

-(Equation 1)

4. Porosity

Porosity (%) G1 10.59 G4 11.83 G2 12.04 G5 12.64 G3 11.93 G6 15.59

At the age of 28 days, it was confirmed that the shrinkage grout composition to which GFA was added exhibited a lower porosity compared to the grout composition to which RFA was added. This confirms that the GFA grout cured body has a more compact microstructure than the RFA grout cured body, which is due to the pozzolanic reaction of fly ash that has hydraulic properties such as calcium hydroxide produced by hydration of cement, and the GFA grout composition is composed of the RFA grout composition. This is because it causes a more active pozzolanic reaction.

---(식 2)

--- (Equation 2)

Through the pozzolanic reaction formula of (Formula 2), C-S-H (Calcium Silicate hydrate) is generated to reduce porosity and contribute to strength enhancement.

5. conclusion

In the present invention, fly ash was applied as an admixture of a non-constricted grout for the purpose of environmental pollution, efficient use of resources, and securing economic efficiency due to cement replacement. Accordingly, the flow rate of fly ash was varied, and flow, flow time, condensation, bleeding, length change rate, and compressive strength experiments were carried out at 7 mixing ratios.

1) The Flow Table Test, which was conducted to evaluate the workability, satisfies all the criteria for non-shrink grout performance under all mixing conditions. In the flow time experiment, which was additionally performed to grasp the trend of flow characteristics, it was confirmed that the grout with GFA had no significant difference in the flow time, while the grout with RFA increased in flow time as the content increased.

2) The slurry curing properties of the GFA non-shrink grout did not cause bleeding under all mixing conditions. It was found that the higher the fly ash content, the shorter the setting time, and when GFA was applied as an admixture than RFA, the setting time was slightly delayed. In addition, the slurry curing properties of the GFA non-shrink grout met performance criteria under all formulation conditions.

3) As the fly ash content applied as a grout admixture increased, the rate of change in length tended to decrease slightly, which was judged to be because the amount of cement affecting the drying shrinkage decreased.

Among the compounding conditions in Table 1, the largest change rate in length was Ref without fly ash, and was 0.0005%.

4) Two grouts (G1, G2) with 10% by weight of GFA and 20% by weight of GFA were compared with Ref as the age increased in compressive strength characteristics, exceeding the strength level, or securing a higher level of strength value.

Based on the above results, GFA-added non-constricted grout formulations G1 and G2 satisfy both performance criteria. In particular, when compared with Ref in the compressive strength characteristics, it was confirmed that the activity exceeds 100%.

Therefore, it was considered that the compounding conditions G1 and G2 with fly ash as the admixture capable of replacing cement with the improvement of fluidity and strength of the non-constricted grout were the most efficient.

The active powder non-shrinkable grout composition to which the pulverized fly ash of the present invention is applied as a miscible material is pulverized fly ash generated in a thermal power plant (GFA; Ground Fly Ash) to increase particle energy and then applied as a non-shrinkable grout material. It improves fluidity, improves durability and enables strength to replace cement with expression of strength, effectively solving environmental pollution problems and efficient use of resources, and high cost of existing solidified materials due to cement replacement. There is a very useful effect that can be saved.

The present invention has been described in detail with reference to the presented embodiments so far, but those skilled in the art can make various modifications and modified inventions without departing from the technical spirit of the present invention with reference to the presented embodiments. will be. The present invention is not limited by such modified and modified inventions, but is limited by the appended claims.

Claims (3)

100 parts by weight of a mixture of 10-20% by weight of fly ash crushed in Portland cement,
35 to 45 parts by weight of water,
Fine aggregate 50 ~ 65 parts by weight,
Water reducing agent 0.5 to 1 part by weight,
4-6 parts by weight of calcium sulfo-aluminate,
Active powder non-shrink grout composition to which pulverized fly ash is applied as an admixture, characterized in that 0.5 to 2 parts by weight of ethylene-vinyl acetate is mixed. The method according to claim 1,
Fly ash is an active powder non-shrink grout composition to which a pulverized fly ash is applied as an admixture, characterized in that it is crushed to 6500 to 7500 cm ² / g. The method according to claim 1,
The water-reducing agent is a lignin sulfonate-based, naphthaline sulfonate-based, melamine sulfonate-based, or polycarboxylic acid salt-based active powder non-shrinking grout composition, characterized in that the pulverized fly ash is applied as a admixture.

Images