KR101121724B1 - A composition of cement zero concrete using the mixed blast slag, powder type sodium silicate and desulfurization gypsum as binder and method for it - Google Patents

Abstract

The present invention relates to a cementless concrete composition using a binder comprising a blast furnace slag, powdered sodium silicate, desulfurized gypsum, and to a method of manufacturing cementless concrete, the purpose of which is blast furnace slag instead of cement to discharge a large amount of carbon dioxide By using a binder composed of powdered sodium silicate and desulfurized gypsum in an appropriate ratio, it is to provide a cementless concrete composition having a compressive strength of 25 ~ 65MPa grade and excellent workability and room temperature curing, and a method of manufacturing the same.

The present invention for achieving the above object in the concrete composition comprising a binder, fine aggregate, coarse aggregate, blending water, the binder comprises blast furnace slag, powdered sodium silicate and desulfurized gypsum, the ratio thereof is blast furnace slag 77 ~ 83 wt%, powdered sodium silicate 15-18 wt%, desulfurized gypsum 2-5 wt%.

Concrete, binder, blast furnace slag, powdered sodium silicate, desulfurized gypsum

Description

COMPOSITION OF CEMENT ZERO CONCRETE USING THE MIXED BLAST SLAG, POWDER TYPE SODIUM SILICATE AND DESULFURIZATION GYPSUM AS BINDER AND METHOD FOR IT}

The present invention relates to a cementless concrete composition using a binder comprising a blast furnace slag, powdered sodium silicate, desulfurized gypsum, and to a method for producing cementless concrete, and more particularly, to a blast furnace slag, powdered sodium silicate, and desulfurized gypsum. The present invention relates to a cementless concrete composition and a method of manufacturing the same, which not only activate the reaction of concrete but also enhance the strength of concrete.

With various efforts to prevent global warming (adopted in 1997, ending the Kyoto Protocol in effect in 2005), in December 2007, the Bali Roadmap was adopted in Bali, Indonesia, until 2009. Negotiations are in progress for a climate change agreement. Accordingly, there is a need to significantly reduce the amount of greenhouse gas emissions such as carbon dioxide worldwide.

Meanwhile, since the cement industry is a major carbon dioxide emission industry in addition to the steel industry, about 0.9 tons of carbon dioxide is produced to produce 1 ton of cement, which is the basis for the production of concrete. Therefore, methods and alternative materials are urgently required.

Domestic cement production is about 60 million tons a year, which is about 55 million tons of carbon dioxide emissions. As part of the remedy, research to replace cement using industrial by-products is constantly underway.

Domestic and international blast furnace slag, fly ash, and some mixed with cement has been applied to a lot of concrete, but this method has a limit in dramatically reducing carbon dioxide.

Overseas, the technology of alkali-activated cement (concrete) by polymerization reaction was conceptually established by Davidovits (France) in 1978 as a mechanism for using kaolinite mineral and having a structure similar to zeolite. There was no practical use because of economics.

As a conventional technique of producing concrete using only coal ash without using cement at all, a method capable of inducing a reaction by destroying the glassy film of coal ash through a high temperature curing process of 60 ° C. or more, thereby securing 30 MPa or more. have.

However, this method has a problem of energy consumption and carbon dioxide emission due to high temperature curing.

In addition, in the prior art, there is a case in which metakaolin is used, but since the kaolin is calcined at 700 to 800 ° C. to use metakaolin, carbon dioxide is discharged in this process, and the price is expensive, so there is a problem in practical use.

In the prior art, there is a method for producing cement concrete using blast furnace slag alone and alkali activators such as liquid NaOH and KOH having high alkalinity. However, the concrete by this method has a compressive strength of about 50MPa even at room temperature, but it is difficult to secure workability due to a sudden drop in fluidity and initial sudden phenomena, and it is a problem in practical use such as large shrinkage.

The present inventors have repeatedly studied and experimented to use the blast furnace slag as a binder of concrete, and the present invention proposes the present invention, instead of cement which emits a large amount of carbon dioxide, blast furnace slag, powdered sodium silicate and desulfurized gypsum. By using a binder composed of a proper ratio, excellent workability and room temperature curing is possible to provide a cementless concrete composition of 25 ~ 65MPa grade strength and its manufacturing method, and its purpose.

Concrete composition of the present invention for achieving the above object is a concrete composition comprising a binder, fine aggregate, coarse aggregate, blending water, the binder comprises blast furnace slag, powdered sodium silicate and desulfurized gypsum, the ratio of these It is characterized in that the slag 77 ~ 83% by weight, powdered sodium silicate 15 ~ 18% by weight, desulfurized gypsum 2 ~ 5% by weight,

In addition, the concrete manufacturing method of the present invention for achieving the above object in the method for producing a concrete composition comprising a binder, fine aggregate, coarse aggregate, the process of mixing the blending water, stirring, curing process, the binder The blast furnace slag is characterized by consisting of 77 to 83% by weight, powdered sodium silicate 15 to 18% by weight, desulfurized gypsum 2 to 5% by weight.

As described above, the non-plastic binder and the concrete composition using the same have a compressive strength by presenting a suitable mixing ratio of a bottom ash, a sodium or / and potassium-based alkaline inorganic material, a sodium silicate, and a ratio of water and the binder. There is an advantage that can be secured in the 25 ~ 55MPa range. In addition, the concrete composition according to the present invention has the advantage that the fluidity is maintained until a certain time after the concrete is poured to ensure sufficient workability.

Cementium concrete composition of the present invention as described above and a method for producing the same, blast furnace slag, powdered sodium silicate, desulfurized gypsum 5 ~ 40 without presenting a binder and a suitable mixing ratio of the binder and the blending water by presenting a suitable mixing ratio Compressive strength can be secured to a range of 25 ~ 65MPa even at room temperature of ℃ ℃, there is an advantage to provide a concrete composition that maintains fluidity until 1 hour 30 minutes after concrete production,

In addition, the cementless concrete composition of the present invention and its manufacturing method is excellent in dry shrinkage and durability by powdered sodium silicate and the like, replacing the ordinary concrete using cement has an advantage that can be sufficiently applied to the concrete structure,

In addition, the cementless concrete composition of the present invention and a method of manufacturing the same by using powdered sodium silicate, NaOH, liquid sodium silicate and water in the liquid alkali activator must be produced through a constant ratio and complex process Anyone can measure and manufacture in the field without any hassle, and there is an advantage of ease of construction.

In addition, the cementless concrete composition of the present invention and its manufacturing method do not use any cement and do not require high temperature curing in the production of concrete, so that a large amount of CO _{2 is} produced during cement production and concrete production. It can reduce the generation of gas has the advantage of reducing environmental pollution,

In addition, the cement concrete composition of the present invention and the method of manufacturing the blast furnace slag as an industrial by-product is recycled as well as an economic burden for securing landfills, as well as an advantage that can reduce many environmental problems caused by leachate generated during landfill There is this.

Hereinafter, the present invention will be described in more detail.

Concrete according to the present invention comprises a binder, fine aggregate, coarse aggregate, blending water, the binder is composed of blast furnace slag, powdered sodium silicate, desulfurized gypsum.

The desulfurized gypsum and the blast furnace slag is produced by the reaction of Hydration (Ettringite; 3CaOAl ₂ O ₃ 3CaSO ₄ 32H ₂ O) in the early stages of regeneration, desulfurized gypsum and blast furnace slag as the age of Calcium hydroxide (Ca (OH) ₂ ) produced by the hydration reaction of the stimulation of the blast furnace slag to exhibit the potential hydraulic properties to activate the reaction of the concrete.

In addition, the powdered sodium silicate and the blast furnace slag is to produce calcium silicate hydrate (CSH gel; 3CaO.2SiO ₂ 3H ₂ O) by the hydration reaction and polymerization (Polymersation) to enhance the strength of the concrete.

Thus, by using blast furnace slag, powdered sodium silicate and desulfurized gypsum as binders, blast furnace slag and desulfurized gypsum can be used without cement so that the potential hydraulic properties of blast furnace slag can be exhibited without calcination. The reaction of sodium will increase the strength.

The blast furnace slag is added in a ratio of 77 to 83% by weight based on the total weight of the binder, because if the ratio is less than 77% or more than 83% by weight there is a problem in the desired strength. In consideration of strength and reactivity, the blast furnace slag is more preferably 78 to 82% by weight, most preferably 80% by weight.

The blast furnace slag powder is preferably 3,300 ~ 8,200cm ² / g, which is less reactive when the powder density of blast furnace slag less than 3,300cm ² / g, the powder is 8,200cm ² / g This is because the reactivity is large, but because the workability is slightly lowered and is not sold as a normal product, the economic efficiency may be lowered because it has to go through a grinding process or a classification process for fine powdering. The blast furnace slag is more preferably 6,100 ~ 6,300m ² / g, and most preferably 6,200m ² / g in consideration of strength expression and reactivity.

The powdered sodium silicate is added in a proportion of 15 to 18% by weight based on the total weight of the binder, but if the ratio is less than 15% by weight, the hydration reaction and the polymerization reaction are weakened, resulting in a small strength, and exceeding 18% by weight. This is because there is a problem in that there is a problem in that the workability is not greatly improved even when the strength is increased due to rapid freezing, and the effect on economic efficiency is not significant. In consideration of workability and strength, the powdered sodium silicate is more preferably 16-18% by weight and most preferably 17% by weight.

It is preferable to use a powdered sodium silicate having a molar ratio of SiO ₂ to Na ₂ O of 2.3 to 3.4. This means that when the molar ratio of SiO ₂ to Na ₂ O of powdered sodium silicate is less than 2.3, the viscosity of concrete rapidly increases. The increase in slump decreases not only the workability but also decreases the Si component required for the polymerization reaction, and thus the long-term strength is decreased. When the molar ratio exceeds 3.4, it does not affect the workability. This is because there is a problem of decreasing the strength. In consideration of the workability and strength of the powdered sodium silicate, a molar ratio of SiO ₂ to Na ₂ O is more preferably 3.0 to 3.2.

The desulfurized gypsum is added in a ratio of 2 to 5% by weight based on the total weight of the binder, but if the ratio is less than 2% by weight, the formation of ettringite is reduced at the early stage of age, so that the initial strength is lowered and the shrinkage is slightly increased. This is because there is a problem, and when the content exceeds 5% by weight, not only the workability is lowered, but also the ettringite is excessively generated, which causes cracking of the concrete due to expansion, thereby lowering the strength.

In consideration of the initial strength and workability, the desulfurized gypsum is more preferably 3-4% by weight, most preferably 3% by weight.

The desulfurized gypsum is preferably at least 95% purity, because when the desulphurized gypsum is less than 95% purity is less likely to be reactive to achieve a certain strength of the concrete, it is difficult to control the concrete quality to be.

In addition, in order to obtain the cementless concrete composition of the present invention, it is preferable that the mixing ratio of the blending water and the binder is in the range of 25 to 60% by weight ratio (weight ratio of the binder to the blending water, blending water-binder ratio, the same). This is effective to increase the strength when the mixing ratio of the blending water and the binder is less than 25%, but the workability is lowered, and the economic efficiency is reduced by using a large amount of other admixtures such as a water reducing agent. This is because there is a problem in that the sharpness is lowered and the compressive strength cannot be applied to the concrete structure with the compressive strength of less than 25 MPa, and the dry shrinkage is increased. The more preferable compounding ratio is 33 to 37%, and the most preferable compounding ratio is 35%.

In addition, the present invention proposes a method for producing concrete by combining the blast furnace slag, powdered sodium silicate and a binder containing desulfurized gypsum, such a concrete manufacturing method is a mixture of the binder, fine aggregate, coarse aggregate and water, etc. It is prepared through a process of stirring and curing. The said mixing | blending, stirring, and curing can be performed by a conventional method, and the additive etc. which are added generally can also be added.

Hereinafter, the present invention will be described in more detail with reference to Examples.

Embodiments according to the present invention can be modified in many different forms, the scope of the present invention is not limited to the embodiments described below.

≪ Example 1 >

Effect of Blast Furnace Slag Powder

In cementless concrete composition set forth in this invention, in order to analyze the effect of the degree of blast furnace slag powder, to the degree of blast furnace slag powder, each having the components as shown in Table ^{1 2,700cm 2 / g, 3,300cm 2} / g , 4,500cm ² / g, 6,200cm ² / g, 8,200cm ² / g, 10,100cm ² / g was prepared and adjusted, these blast furnace slag was used by 80% by weight relative to the total weight of the binder.

division SiO ₂
(%) Al ₂ O ₃
(%) Fe ₂ O ₃
(%) CaO
(%) MgO
(%) SO ₃
(%) lg. loss
(%) density
(g / cm ³⁾ Powder
(cm ² / g) BS2700 33.33 15.34 0.44 42.12 5.70 2.08 0.03 2.90 2,700 BS3300 33.33 15.34 0.44 42.12 5.70 2.08 0.03 2.90 3,300 BS4500 33.33 15.34 0.44 42.12 5.70 2.08 0.03 2.90 4,500 BS6200 33.33 15.34 0.44 42.12 5.70 2.08 0.03 2.90 6,200 BS8200 33.33 15.34 0.44 42.12 5.70 2.08 0.03 2.90 8,200 BS10100 33.33 15.34 0.44 42.12 5.70 2.08 0.03 2.90 10,100

And together with the blast furnace slag powdered sodium silicate (molar ratio of SiO ₂ and Na ₂ O 3.1) 17% by weight relative to the total weight of the binder, desulfurized gypsum having a purity of 95% or more to 3% by weight of the total weight of the binder Was constructed.

In addition, the blended water consisting of tap water and the binder was used as a weight ratio of 35%, the remaining fine aggregate, coarse aggregate was used in the same proportion as conventional concrete. And ordinary concrete (water-cement ratio 45%) using normal cement was prepared to compare with cement concrete.

The slump and the compressive strength of the prepared concrete were measured and the results are shown in FIGS. 1 and 2, respectively.

Here, the slump test was evaluated for workability immediately after discharging from the mixer by mixing concrete according to KS F 2402, and the compressive strength was Φ100 × 200mm circumferential test specimens were cured for 1 day at 20 ℃ and then dried ( Curing was carried out at 65 ± 5% humidity) and measured according to KS F 2405 at 3, 7, 28 and 91 days of age.

As can be seen in Figure 1, as the powder density of the blast furnace slag was found to be slightly lower in the workability, but the slump up to 8200cm ² / g slump is 210 ~ 190mm range, but the fluidity is not large, powder 10,100cm ^{In the} case of ² / g, the slump was found to significantly reduce the fluidity to about 150mm.

From the results of FIG. 2, the smaller the powder density of the blast furnace slag, the lower the strength expression. When the powder degree is 2,700 cm ² / g, the strength is relatively low at 25 MPa or less even at 28 days and 91 days. In addition, when comparing the powder degree of 8,200cm ² / g and 10,100cm ² / g, it was found that the powder intensity of 10,100cm ² / g was slightly effective in improving the initial strength until 7 days of age. There was little difference in degrees.

In conclusion, when cementless concrete is manufactured using a binder composed of blast furnace slag, powdered sodium silicate and desulfurized gypsum, blast furnace slag has a powder content satisfying the range of 3,300 to 8,200 cm ² / g. The slump of 190mm or more can secure sufficient workability, and the compressive strength in the range of 25 ~ 65MPa compressive strength in 28 days of age can be secured to manufacture cement concrete to meet the user's purpose.

Particularly, considering the workability, strength, and pulverization process, the powder levels of 6,200 cm ² / g and 8,200 cm ² / g do not differ significantly in terms of strength, so the optimum blast furnace slag powder is 6,200 cm ² / g is determined.

<Example 2>

Molar Ratio Effect of SiO ₂ and Na ₂ O on Powdered Sodium Silicate

Mole ratios of SiO ₂ / Na ₂ O 2.2, 2.3, 2.7, 3.1, 3.4, 3.5 in order to analyze the effect of the molar ratio of SiO ₂ and Na ₂ O of powdered sodium silicate in the preparation of cementless concrete compositions presented in the present invention 17% by weight of sodium silicate was used. The binder was used with 80% by weight of blast furnace slag having 4,500 cm ² / g powder and 3% by weight of desulfurized gypsum having a purity of 95% or more.

And the ratio of the mixing water consisting of the tap water and the binder was 35% by weight, and the remaining coarse aggregate and fine aggregate was used in the same manner as in the manufacture of concrete to produce concrete.

The concrete thus prepared was prepared according to KS F 2402 and subjected to slump test and φ100 × 200mm circumferential test specimens, which were cured at 20 ° C for 1 day, and then cured in the air condition (humidity 65 ± 5%). The compressive strength was measured according to KS F 2405 at days, 28 and 91 days. The results are summarized in FIGS. 3 and 4.

As can be seen in Figure 3, as the molar ratio of sodium silicate decreases, the viscosity of the concrete increases, resulting in a decrease in slump, resulting in poor workability. In particular, when the molar ratio of SiO ₂ to Na ₂ O is less than 2.3, the workability is deteriorated, and thus, a chemical admixture such as a high performance water reducing agent is required. In addition, the slump increased from 202 to 207mm in the molar ratio of 3.1 and 3.5.

In addition, from the results of FIG. 4, the lower the molar ratio of the powdered sodium silicate, the lower the long-term intensity expression, and the higher the molar ratio, the lower the initial strength and eventually, the lower the long-term strength. The molar ratio of SiO ₂ and Na ₂ O was excellent in both initial strength and long-term strength at 3.1, and the molar ratio was less than 2.3, which means less Si components for the polymerization reaction. If it is exceeded, it is difficult to use it in concrete structures because Na content is small and the strength of 7 days is relatively low, such as 20 MPa.

In summary, when manufacturing cementless concrete using a binder composed of blast furnace slag, powdered sodium silicate and desulfurized gypsum, the powdered sodium silicate satisfying the molar ratio of SiO ₂ and Na ₂ O in the range of 2.3 to 3.4 In case of using, it is analyzed that cementless concrete can be manufactured with excellent workability and compressive strength. Particularly, powdered sodium silicate having a molar ratio of SiO ₂ and Na ₂ O satisfying 3.1 shows the best results due to its satisfactory workability and excellent strength.

<Example 3>

Effect of Weight Ratio on Binder Material

In order to analyze the effect of the weight ratio of the blast furnace slag, powdered sodium silicate and desulfurized gypsum, the constituent material of the binder when preparing the cement concrete composition presented in the present invention, the blast furnace slag having a powder degree of 4500 cm ² / g, SiO ₂ / Na Powdered sodium silicate with a molar ratio of ₂ O of 3.1 and desulfurized gypsum with a purity of at least 95% by weight 80: 20: 0, 80: 19: 1, 80: 18: 2, 80: 17: 3, 80:16: A binder composed of 4, 80: 15: 5, and 80: 14: 6 was used. And the ratio of the mixing water consisting of the tap water and the binder was 35% by weight, and the remaining coarse aggregate, fine aggregate, etc. were prepared in the same manner as in the conventional concrete production.

The concrete thus prepared was subjected to a slump test in accordance with KS F 2402, and a φ100 × 200 mm column test specimen was made and cured at 20 ° C. for 1 day, followed by curing in a dry state (humidity 65 ± 5%). Compressive strength was measured according to KS F 2405. The results are summarized in FIG. 5.

As can be seen in Figure 5, depending on the weight ratio of the constituent material of the binder, more than 18% sodium silicate, less than 2% desulfurized gypsum, the slump and compressive strength drop is large, greater than 5% desulfurized gypsum, less than 15% sodium silicate and slump It was found that the compressive strength was lowered. In other words, when sodium silicate is more than necessary, the workability decreases due to the occurrence of rapid freezing and the deterioration of strength expression due to the lack of hydration reaction in the early age due to the lack of desulfurized gypsum. When used, it was found that the workability was reduced due to the occurrence of rapid freezing, and the strength was decreased due to the lack of sodium silicate, which did not activate the hydration reaction and the polymerization reaction at a long age.

From the above results, when the composition ratio of the binder is in the range of 15 to 18% by weight of powdered sodium silicate and 2 to 5% by weight of desulfurized gypsum, the workability and compressive strength are excellent. Particularly, the blast furnace slag , Powdered sodium silicate and desulphurized gypsum are 80: 17: 3 by weight, which is the best in terms of compressive strength and satisfactory workability.

<Example 4>

Effect of Weight Ratio of Mixing Water-Binder

Formulated water consisting of tap water, blast furnace slag (powder degree 4500cm ² / g), powdered sodium silicate (molar ratio of SiO ₂ / Na ₂ O 3.1), desulfurized gypsum having a purity of 95% or more In order to analyze the effect of the blending ratio of the binder composed of 80: 17: 3 by weight, the ratio of the blended water and the binder was 23, 25, 30, 35, 45, 55, 60, 65% by weight, and the remaining coarse aggregate was , Fine aggregates and the like were prepared in the same manner as in normal concrete production.

The concrete thus prepared was subjected to a slump test in accordance with KS F 2402, a φ100 × 200 mm column test specimen was made, and cured for 1 day at 20 ° C., followed by curing in an air condition (humidity 65 ± 5%). The compressive strength was measured according to KS F 2405 at. The results are summarized in FIG. 6.

As can be seen in Figure 6, the smaller the composition ratio of the blended water and the binder, the smaller the quantity, the fluidity is lowered, but the compressive strength was found to be improved. This result shows the same result in ordinary concrete. Specifically, when the ratio of the blended water to the binder is less than 25%, the slump drop is sharply lowered, and it is necessary to use a chemical admixture such as a high-performance sensitizer. When the ratio of the blended water to the binder is greater than 60%, the slump increase is not large and the compressive strength is increased. Due to the sharp drop, it is difficult to apply to concrete structures at 65% of strength at 65%.

From the above results, the ratio of the blended water consisting of tap water and the binder composed of blast furnace slag, powdered sodium silicate and desulfurized gypsum was found to be excellent in construction and compressive strength when it was composed in the range of 25 to 60% by weight. We believe it will be possible to manufacture concrete. Particularly, when the weight ratio of the blended water and the binder is 35%, the workability is satisfied and the compressive strength is excellent.

Example 5

Comparison with Conventional Liquid Alkali Activators

In order to compare the cementless concrete using the powdery binder of the present invention and the cementless concrete using the conventional liquid alkali activator, the concrete was prepared using the formulation using BS4500 (blast furnace slag powder degree of 4,500 cm ² / g) in Example 1. Prepared. The same powder was also used for the manufacture of cementless concrete, and a liquid alkali activator composed of 9% NaOH and liquid sodium silicate (molar ratio of SiO ₂ and Na ₂ O 3.1 by 50%) was used. The rest of the material composition is the same as the formulation of the present invention.

The test was carried out in a slump test and a compressive strength test in a similar manner to Example 1, but the slump test was evaluated for workability by measuring the slump until 1 hour and 30 minutes elapsed according to KS F 2402 after the concrete was prepared. . The results of slump and compressive strength are shown in FIGS. 7 and 8, respectively.

And based on the above formulation was evaluated for dry shrinkage, sulfate, freeze-thawing, carbonation, salt resistance, the results are shown in Table 3, respectively.

At this time, dry shrinkage was made in 100 × 100 × 400m footnote test specimens and cured at 60 ℃ for 1 day, and then exposed to dry condition (temperature 20 ± 2 ℃, humidity 65 ± 5%), followed by KS F 2424. Measured by day.

In the sulfate test, φ100 × 200mm columnar specimens and 100 × 100 × 400m footnote specimens were prepared and cured at 60 ° C for 1 day, then cured at 20 ° C in air condition (humidity 65 ± 5%) for 28 days, and then 10% sodium sulfate. After soaking in the solution for 91 days, the change in compressive strength and length change rate were measured.

In the freeze-thawing test, 100 × 100 × 400m footnote specimens were prepared and cured at 60 ° C for 1 day, and then cured for 28 days at 20 ° C in air condition (humidity 65 ± 5%), and then the temperature range was + 4 ° C ~- The relative dynamic modulus was measured by 18 ° C. and 1 cycle time of 2 hours 40 minutes to 300 cycles.

In the carbonation test, φ100 × 200mm columnar specimens were prepared and cured at 60 ° C. for 1 day, and then cured at 20 ° C. in a dry state (humidity 65 ± 5%) for 28 days, followed by carbon dioxide concentration of 5%, temperature of 30 ° C., and humidity. The test body was exposed for 91 days in a chamber controlled at 50%, and then the test body was bisected and split to spray a 1% solution of phenolphthalene on the surface to measure the carbonation depth.

Salt resistance was prepared by φ100 × 50mm specimen and cured for 1 day at 60 ℃, then cured for 28 days at 20 ℃ in air condition (65 ± 5% humidity), and then evaluated by electrical accelerated test according to ASTM C 1202. .

As can be seen in Figure 7, the cement concrete prepared using the conventional liquid alkali activator is the initial slump is lowered and the slump is rapidly reduced over time after 30 minutes after the work is produced The castle was not secured. In contrast, in the case of using the powdery binder of the present invention, the initial slump is 200 mm, and even after one hour, the slump is maintained at 200 mm to ensure sufficient workability.

In addition, the compressive strength of FIG. 8 shows that the cementless concrete using the conventional liquid alkali activator increases the initial strength, but the strength expression gradually decreases thereafter. On the contrary, when using the powdery binder of the present invention, the initial strength is lower than that of using the conventional liquid alkali activator, but is expressed as more than ordinary concrete, and as the age is increased, it is equal to or more than the liquid alkali activator. It has been shown to be expressed.

combination
Dry shrinkage
(× 10 ^-6 )
sulfate Carbonation depth
(14 weeks of age)
(mm) Freeze thawing
Relative dynamic modulus
(%) Salt
Total charge
(Chrome) Intensity change rate
(%) Length change rate
(%) General Concrete 680 5.4 3.5 13 85 2450 Liquid Alkali Activator Cement Concrete
(Prior Art)

980

2.7

1.3

9

4

970 Cementless concrete with powder binder
(Invention example)
430
1.7
0.8
6
99
680

As can be seen in Table 2, in the case of cementless concrete using a conventional liquid alkali activator, the dry shrinkage is increased compared to conventional concrete, and the performance of the remaining sulfate, freeze-thawing, etc. are superior to general concrete. Appeared.

On the other hand, in the case of using the powdery binder of the present invention, dry shrinkage was reduced and durability was much higher than that of ordinary concrete, as well as cementless concrete using a liquid alkali activator.

Figure 1 is a graph showing the slump results according to the powder diagram of blast furnace slag.

2 is a graph showing the results of compressive strength according to the powder degree of blast furnace slag.

Figure 3 is a graph showing the slump results according to the molar ratio of powdered sodium silicate.

4 is a graph showing the compressive strength results according to the molar ratio of powdered sodium silicate.

5 is a graph showing the results of slump and compressive strength according to the weight ratio of the binder component material.

6 is a graph showing the results of slump and compressive strength according to the ratio of the mixing water and the binder.

7 is a graph illustrating a comparison result of slump over time of existing concrete and cementless concrete.

8 is a graph showing a comparison result of the expression of compressive strength of concrete and cement concrete.

Claims (12)

In the concrete composition comprising a binder, fine aggregate, coarse aggregate, blending water, The binder includes blast furnace slag, powdered sodium silicate and desulfurized gypsum, and their ratio is 77 to 83% by weight of blast furnace slag, 15 to 18% by weight of powdered sodium silicate and 2 to 5% by weight of desulfurized gypsum. Cemented concrete composition using a binder comprising blast furnace slag, powdered sodium silicate, desulfurized gypsum. The method of claim 1, The blast furnace slag is a cement cement composition using a binder comprising a blast furnace slag, powdered sodium silicate, desulfurized gypsum, characterized in that the powder is 3,300 ~ 8,200cm ² / g. 3. The method of claim 2, The blast furnace slag is a cement cement composition using a binder containing a blast furnace slag, powdered sodium silicate, desulfurized gypsum, characterized in that the powder is 6,100 ~ 6,300m ² / g. The method of claim 1, Cemented concrete composition using a binder comprising a blast furnace slag, powdered sodium silicate, desulfurized gypsum, characterized in that the molar ratio of SiO ₂ and Na ₂ O in the powdered sodium silicate is 2.3 to 3.4. The method of claim 4, wherein Cementium concrete composition using a binder comprising a blast furnace slag, powdered sodium silicate, desulfurized gypsum, characterized in that the molar ratio of SiO ₂ and Na ₂ O in the powdered sodium silicate is 3.0 to 3.2. The method of claim 1, The desulfurized gypsum cement cement composition using a binder comprising a blast furnace slag, powdered sodium silicate, desulfurized gypsum, characterized in that the purity is 95% or more. The method of claim 1, The ratio of the binder is blast furnace slag 78 to 82% by weight, powdered sodium silicate 16 to 18% by weight, desulfurized gypsum 3 to 4% by weight, characterized in that the binder containing blast furnace slag, powdered sodium silicate, desulfurized gypsum Cemented concrete composition used. The method of claim 1, Cemented concrete composition using the binder containing the blast furnace slag, powdered sodium silicate, desulfurized gypsum, characterized in that the weight ratio of the binder to the blended water is 25 to 60%. The method of claim 8, Cemented concrete composition using a binder comprising blast furnace slag, powdered sodium silicate, desulfurized gypsum, characterized in that the weight ratio of the binder to the blended water is 33 to 37%. In the method for producing a concrete composition comprising a binder, fine aggregate, coarse aggregate, the process of mixing the blending water, stirring, curing process, The binder is 77 to 83% by weight of blast furnace slag, 15 to 18% by weight of powdered sodium silicate, desulfurized gypsum 2 to 5% by weight of the manufacturing method of cement cement concrete. The method of claim 10, In the blending process, the binder includes blast furnace slag having a powder degree of 3,300 to 8,200 cm ² / g, powdered sodium silicate having a molar ratio of SiO ₂ and Na ₂ O of 2.3 to 3.4, and desulfurized gypsum having a purity of 95% or more. The method for producing cement concrete, wherein the blended water and the binder are blended at 25 to 60% by weight of the binder to the blended water. The method of claim 11, In the blending process, the binder is a blast furnace slag having a powder degree of 6,100 to 6,300 cm ² / g, powdered sodium silicate having a molar ratio of SiO ₂ to Na ₂ O of 3.0 to 3.2, and desulfurized gypsum having a purity of 95% or more. 79 to 81% by weight of blast furnace slag, 16 to 17% by weight of powdered sodium silicate, and 3 to 4% by weight of desulfurized gypsum, respectively, and the weight ratio of the binder to the blended water is 33 to Method for producing cement concrete, characterized in that to be compounded at 37%.

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