KR20050082083A - Concrete compositions using bottom ash and method of making - Google Patents

Abstract

The present invention relates to a composition of high-performance concrete using bottom ash instead of natural sand, which is gradually being depleted, and a method of manufacturing the same. In order to efficiently use resources by using bottom ash as fine aggregate, water, cement, aggregate In the composition of high-performance concrete used in combination with the general sand, the aggregate is a coarse aggregate of natural crushed stone, the size of the coarse aggregate of natural crushed stone is 10 to 25mm, waste generated in thermal power plants as a substitute for the general sand In bottom ash sand is used, the size of the bottom ash sand is 5mm or less, 20 to 26% of the total required composition components per m 3 as the constituent of the concrete composition, the bottom ash sand is thick Aggregates comprise 34-46% of the total required composition components per m 3 and are admixtures in the composition Fluidizing agent is added, the concrete composition is applied to the concrete design strength of 400 to 800kg / cm ^2.

By using such a composition of high-performance concrete and a method of manufacturing the same, the effect of using a bottom ash as a substitute for artificial aggregate can provide cement concrete having a compressive strength similar to or higher than that of existing products.

Description

Concrete compositions using bottom ash and method of making

The present invention is a ash ash bottom ash attached to a furnace wall, a superheater and a preheater in ash generated after burning coal in a coal-fired power plant as part of a method of replacing the natural or masonry aggregate, which is gradually being depleted, and falls on the boiler floor by its own weight. The present invention relates to a high-performance concrete composition and a method for manufacturing the same, using bottom ash as an alternative, and to applying concrete to a concrete mix to recycle resources that are disposed of in landfills around power plants and to reduce the use of natural aggregates. High performance concrete compositions and methods for their preparation.

Generally, ash is defined as residues remaining after incineration or combustion. The majority of ash is generated from thermal power plants, but also from waste incinerator cogeneration plants and other industrial sites as a result of combustion processes. Ash is an inorganic material (eg SiO ₂ , Al ₂ O ₃ , Fe ₂ O ₃ ) in that it is a remnant of combustion products, but ash is always an unburnt carbon due to the combustion process. It is technically problematic that this incidental content is contained.

Ash is divided into two types according to the particle size. When the particle size is 100 µm or less, it is a fly ash (flying ash), and when it is larger, it is treated as a bottom ash (falling ash).

In total, coal can be divided into anthracite and bituminous coal depending on the degree of carbonization. Anthracite contains about 90-95% of carbon, and bituminous coal has less carbon than anthracite. Peat, peat, and lignite belong to bituminous coals, each containing 60% peat, 70% peat and lignite, and 80-90% carbon. Depending on coal quality, about 30-50% of raw coal remains ash in anthracite coal, and about 10-15% of raw coal is generated in bituminous coal because of its high combustion efficiency.

When the coal powder is burned, the organics are burned as fuel and the inorganics remain "ash". As the ash is dispersed in the boiler flue, heavy particles fall to the bottom of the boiler and light particles are collected by the electric precipitator from the boiler flue while still flying. Ash that falls down due to heavy particles is called a "bottom ash", and ashes that are dispersed and fly and are collected by a dust collector are called "fly ashes".

That is, most of the coal ash is collected in the dust collector or collected at the bottom of the boiler, and the amount of generated ash is 15-45% of the total pulverized coal, and the amount of fly ash collected in the whole coal ash dust collector is about 60-80%. -40% is bottom ash collected from the bottom of the boiler.

The bottom ash is attached to a wall of a boiler, a preheater, a cutter, and the like, and falls to the bottom of the boiler by self-weight or a load fluctuation damper, is integrated in a hopper, and then crushed by a grinder.

Generally, the bottom ash hopper is filled with water at about 60 ° C. This water causes the bottom ash at high temperatures (above 760 ° C.) to be destroyed by thermal shock, the hopper is heated to prevent the bottom ash from joining the melt, and friction with the hopper wall during bottom ash discharge. Reduce resistance, etc.

The bottom ash system basically includes a direct sluicing system, a storage system in dewatering bin, a water recirculation system, and a chain conveyer system.

The concept of this process is briefly described as follows.

In the direct ashing method, the bottom ash discharged from the hopper at the bottom of the boiler is directly transported with water through the recovery pipe to the ash processing plant. The ashing process consists of crushing the bottom ash in a clinker state mixed with water in a pulverizer at the outlet of the hopper and transporting it to the ashing plant by a jet pump. This method is very useful when the distance from the power plant to the ash treatment plant is relatively short, and since the amount of water required for ash treatment is large, the sea water is generally used. In addition, the water used for ashing is recycled to the bottom ash hopper to prevent water pollution and to reduce the amount of water used.

In addition, in the dehydration tank storage method, the crushed bottom ash is moved to a dewatering bin together with water through a return pipe, and stored for at least 24 hours for dehydration. In other words, it is embedded in ash processing plant or used for other purposes. This method is suitable when the bottom ash is used as a subgrade material or cement raw material.

The recirculation method is the same as the dehydration tank storage method in which the bottom ash mixed with water is moved to the dehydration tank and then dewatered.In particular, the water discharged from the dehydration tank is transferred to the sedimentation basin or sedimentation tank and settled. The point is unusual. This method is used in large-scale coal-fired power plants because it can minimize the amount of water used for the ash treatment.

The immersion machine type is a method of installing a submerged chain conveyor at the bottom of the boiler to crush the bottom ash dropped into the bottom of the boiler by quenching water in the hopper and then discharging it out of the hopper using the conveyor. This method has the advantages of small power and installation space, and a small amount of water used for ashing, which is used in Europe mainly in Germany.

Next, the basic chemical and physical properties of the batem ash used in the present invention will be described.

The bottom ash is observed as a dark gray uneven grain, and the particle surface shows a porous surface, and is an irregularly shaped particle having a particle similar to sand and having a size of 5 mm or more in diameter. The main chemicals of the bottom ash include SiO ₂ , Al ₂ O ₃ , Fe ₂ O ₃ , CaO, MgO, Na ₂ O and K ₂ O. Among the bottom ash chemistries, the composition ratio of double silica (SiO ₂ ), alumina (Al ₂ O ₃ ), and iron oxide (Fe ₂ O ₃ ) was 70.0-45.4%, 28.3-15.9%, and 14.3-2.0%, respectively. Occupies a large amount.

Bottom ash does not contain a large amount of glass paste, such as fly ash or blast furnace slag, but it does contain a glass phase that is likely to affect long-term strength.

Table 1 below is a comparison of the chemical composition of the bottom ash and general cement.

(Table 1) Bottom ash and general cement chemical composition

Chemical composition Bottom ash (wt%) Portland Cement (wt%) Boryeong Seocheon ('98) A ('98) B ('02) SiO ₂ 52.0 46.1 48.6 20.5 Al ₂ O ₃ 21.1 18.7 26.7 6.4 Fe ₂ O ₃ 10.87 10.2 5.51 2.9 CaO 4.22 18.8 1.74 61.4 MgO 1.22 1.80 1.04 3.0 SO ₃ 0.06 - 5.07 2.1 Na ₂ O, K ₂ O 1.58 1.79 0.1 2.0

As can be seen in Table 1, the bottom ash may be found that the main constituent chemical components are present in similar sizes, although the main constituent chemical components are somewhat different according to region and year. Among them, it is found that since CaO is contained in a large part, it can play a role in the strength expression by cement and hydration reaction.

In addition, the bottom ash is mostly gray in color, depending on the production environment, ranging from dark yellow to blackish-white. The unburned carbon particles are black in color, while the silica and alumina content is grayish white and yellow in color. Bottom ash does not meet the conditions such as particle shape or chemical composition to serve as a binder. As shown in Table 2 below, which shows the physical properties of the bottom ash, the specific gravity of the bottom ash is about 2.1 to 2.7. The bottom ash has a dry weight of 720-1600 kg / m 3, no plasticity, and an absorption rate of 2.0% -10.0%.

Table 2 Physical Properties of Bottom Ash

characteristic importance Dry weight Plasticity Water absorption Bottom ash 2.1 to 2.7 720 to 1600㎏ / ㎥ None 2.0-10.0%

As shown in Table 3 below, the particle size distribution through the sieve of the bottom ash shows a particle size distribution similar to that of the fine aggregate.

Table 3 Particle size distribution of bottom ash and fine aggregates (sand)

division sand % B / A % 4.75 mm 6.6 g 0.66% 57.7 g 5.77% 4.75 or less 2.36 or more 26.2 g 2.62% 148.3 g 14.83% 2.36 or less 1.18 or more 72.2 g 7.22% 217.2 g 21.72% 1.18 or less 850㎛ or more 111.7 g 11.17% 141.6 g 14.16% 850 or less 600㎛ or more 138.8 g 13.88% 80.2 g 8.02% 600 or less 300㎛ or less 595.4 g 59.44% 171.4 g 17.14% 300㎛ or less 49.1 g 4.91% 183.6 g 18.36% Gross weight 1 kg 100% 1 kg 100%

The amount of ash produced depends on the carbon. Anthracite accounts for about 30-40% of ash generated, of which about 60-80% is fly ash and 20-40% is treated as bottom ash. However, in the case of bituminous coal, the combustion efficiency is high and ash is not generated as much as anthracite coal. It is usually about 10-20% of the raw coal and the ratio of fly ash to bottom ash is about 7: 3. The amount of fly ash and bottom ash generated is shown in Table 4.

(Table 4) Coal Consumption and Bottom / Fly Ash Generation

                                                  (Unit: thousand tons)

year Coal consumption Fly ash Bottom ash Bituminous coal hard coal Bituminous coal hard coal Bituminous coal hard coal 1987 4,957 2,183 652 1,090 39 114 1989 5,894 2,337 783 1,063 35 112 1991 7,017 2,044 781 1,284 35 134 2001 29,214 1,334 4,382 600 197 63 2006 33,732 850 5,060 382 227 40

The quality of fly ash is improved with the improvement of power generation facilities, and its recycling rate is gradually increasing to 32.2% in 1998 and 42.5% in 1999, and more than 90% is used as concrete admixture and cement raw material. Currently, about 5.5 million tons of fly ash and 270,000 tons of bottom ash are expected in 2006 when the long-term electricity supply and demand plan is completed in Korea.

Usually, these coal ashes, which are by-products of coal-fired power plants, were treated mainly at the coal ash processing plant (company head) installed at the point where environmental preservation and resource recycling were emphasized. In the past, when the utilization of land was high, it was rather easy to process, but it is relatively difficult to find a manager who needs three to four times the size of the power plant facilities due to the rapid increase in factory land and land price due to the recent high economic growth rate. The reality is getting harder.

Therefore, fly ash has been used in various fields such as cement admixtures, landfills, land improvement materials, lightweight aggregates, etc., as a result of steady research in various research institutes and academia. Furnaces are active, accounting for about 90% of the total recycling rate.

An example of using the bottom ash as an aggregate is to replace a part of the natural and artificial aggregate (Korean Patent Publication No. 97-074076), or to use a part of the bottom ash of the thermal power plant in the manufacture of lightweight construction materials (Korea Patent Publication) Publication No. 97-061815) and fly ash, gypsum, calcium carbonate and lime and the like to extrude at a high pressure to produce a brick product (US Patent 5.358, 760). In addition, research to manufacture high strength cement mortar using bottom ash as fine aggregate is being conducted in various institutions.

However, in most cases of bottom ash, it is simply landfilled at the company site near the power plant, mixed with fly ash inland or coastal landfill, and used in small amounts as roadbed soil material around the power plant. Therefore, as a main material causing the problem of environmental pollution, as well as the difficulty of securing the processed paper, the treatment thereof has become a problem.

Looking at the main status of aggregate used as a component of domestic concrete, river aggregates accounted for more than 90% until the early 1980s, and the main source of aggregate was river or river. However, river aggregates have been used for a long time and the collection of aggregates is restricted in order to maintain and protect the rivers, making it difficult to obtain high-quality river aggregates and exhausting them. . Recently, as a countermeasure against this, crushed aggregate, sea sand, concrete waste materials, etc. are already in use, and in addition, the use of artificial aggregates and blast furnace slag aggregates has been actively examined and activated.

Therefore, in light of the trend of depletion of natural aggregates, the inventors of the present invention efficiently utilize resources in addition to solving environmental problems caused by landfilling of waste materials if bottom ash generated in thermal power plants and currently disposed of landfills is used as concrete aggregates. Considering that it will be of great significance in terms of its use, the application of bottom ash as a high-performance concrete aggregate was examined.

An object of the present invention is to solve the problems of the prior art as described above by applying the bottom ash as a substitute material for the electric pole or pile concrete to the bottom ash which can recycle the resources that are currently disposed in the landfill around the power plant It is to provide a high-performance concrete composition and a method of manufacturing the same that can be applied to high-performance concrete by developing high-strength cement mortar while using it as fine aggregate (sand).

Another object of the present invention is a coarse aggregate (-25mm) using natural crushed stone aggregate used in general ready concrete, and bottom ash sand as a natural crushed aggregate, 28 days underwater curing strength can be applied to Jeonju or pile concrete It is to provide a high performance concrete composition and a method of producing the same.

In order to achieve this purpose, as a first step, instead of the standard yarn suggested by KS L 5105, it was replaced with bottom ash so that the compressive strength of cement mortar was 600-800 kg / cm ² (age 28 days).

For this, the cement / bottom ash ratio was controlled, the pozzolanic admixture selection test and the high fluidizing agent selection test were performed.

In addition, the coarse aggregate (-25mm) for the purpose of using the natural crushed aggregates used in the general ready-mixed concrete, natural crushed aggregates replaced by bottom ash sand, 28 days underwater curing strength can be applied to Jeonju or pile concrete In order to develop high-performance concrete (compressive strength: 600-800 kg / cm ² ), coarse aggregate size change, fluidizing agent comparison, pozzolanic addition, compressive strength change according to cement amount were tested.

In the composition of high-performance concrete used by mixing water, cement, aggregate, and general sand of the present invention for achieving the above object, the aggregate is a coarse aggregate of natural stone, the size of the coarse aggregate is 10 to 25 mm Bottom ash sand, which is a waste generated from a thermal power plant, is used as a substitute for the general sand, and the size of the bottom ash sand is 5 mm or less, and the bottom ash sand is a total required composition per m3 as a component of the concrete composition. 20 to 26% of the constituents are included, and the natural crushed coarse aggregate contains 34 to 46% of the total required composition constituents per m 3, admixtures and glidants are added to the composition, and the concrete composition has a design strength of concrete 400 To 800kg / cm ² .

In the composition of the high-performance concrete according to the present invention, the admixture is a pozzolanic admixture, and is characterized in that it is added about 10% to the amount of cement.

In the composition of the high-performance concrete according to the present invention, the fluidizing agent is PCA (Poly Carbonate Acid), and the composition of the high-performance concrete using the bottom ash, characterized in that the addition of 0.25 to 0.75% to the cement amount.

In addition, the method for producing a composition of the high-performance concrete of the present invention for achieving the above object is a method for producing a composition of high-performance concrete using a mixture of water, cement, aggregate, and general sand, the aggregate of 10 to 25mm A process for preparing coarse aggregate of natural stone, a process of collecting bottom ash having a particle diameter of 5 mm or less using a sorting machine among bottom ash generated in a thermal power plant, etc., and the total required composition per m3 of the cement and the high-performance concrete. 20 to 26% bottom ash sand, 34 to 46% natural crushed coarse aggregate of the total required composition constituents per m 3 of the high performance concrete, and a process for mixing admixtures and glidants.

In addition, in the method for producing a composition of high performance concrete according to the present invention, the admixture is a pozzolanic admixture, and is characterized in that it is added about 10% to the amount of cement.

In addition, in the method for producing a composition of high-performance concrete according to the present invention, the fluidizing agent is PCA, characterized in that 0.25 to 0.75% is added to the amount of cement.

In addition, in the method for producing a composition of high performance concrete according to the present invention, the concrete composition is characterized in that it is applied to the design strength 400 to 800kg / cm ² of concrete.

Hereinafter, embodiments of the present invention will be described so that those skilled in the art can easily carry out the present invention.

First, the aggregate is demonstrated as a factor on concrete strength.

Aggregate is a material of minerals constituting mortar or concrete in combination with a binder such as cement, and since it occupies 70% or more of the concrete volume, it has a great influence on the strength, durability, workability, and adhesion of concrete or mortar.

Aggregate quality greatly affects the properties of concrete and mortar. Therefore, selecting and using aggregate suitable for the compounding condition may be the biggest reason for producing high strength mortar. Aggregate properties are not the properties of individual aggregate particles, but the properties of the whole made up of small and large particles, as follows: ① possessing strength to secure concrete strength, ② specific gravity to satisfy the specific gravity of concrete, ③ weather conditions and Durable to the conditions of use, ④ It must be granular and granular to make concrete with good fluidity, ⑤ It does not contain harmful substances that adversely affect the properties of concrete, ⑥ It needs to be fireproof. .

The specific gravity of concrete using ordinary aggregates is about 2.3, but the lightweight aggregates and heavy aggregates can be used to obtain concrete with specific gravity from about 1 to about 4. The specific gravity and absorption rate of aggregates are correlated with each other, although they vary by mother rock. As the weathering of the rock progresses, fine cracks are generated inside, which leads to a decrease in specific gravity and an increase in absorption rate. Therefore, concrete using such aggregates generally has a low strength and modulus of elasticity, an increase in dry shrinkage, and neutralization and freeze-thawing. The durability tends to be lowered.

The particle size distribution of aggregate is investigated by the sieve test method of aggregate. The size of the sieve used for the test was prescribed | regulated as follows.

  Aggregate: 0.15, 0.3, 0.6, 1.2, 2.5, 5, 10mm

  Coarse aggregate: 2.5, 5, 10, 15, 20, 25, 30, 40, 60, 80, 100mm

Aggregates should be stable against repetitive vapor phase actions such as solar radiation, temperature changes, water absorption and freeze thawing. Stability is shown to the extent that the aggregate is broken by repeating the operation of immersing the aggregate in a saturated solution of sodium lactate and drying. However, since the expansion pressure does not work effectively on aggregates with many voids and difficult to absorb, such as artificial lightweight aggregates, this stability test is not applied. Aggregate durability is examined by the freeze thaw test for concrete using the aggregate. The abrasion resistance of aggregates is to determine the loss of abraded aggregates when rotating aggregates and steel balls in drums. It is specified as 30% or less in paving concrete and 40% or less in dam concrete. The fire resistance of the aggregate is obtained by heating the coarse aggregate particles at 800 ° C for 30 minutes to obtain the weight reduction rate and the reduction rate of the number of damaged particles. If both the weight reduction rate and the number reduction rate are 5% or less, the fire resistance is acceptable. Shall be.

Because aggregates contain substances that weaken the properties of concrete, the types of pests and their tolerances are determined (see Table 5).

(Table 5) Regulations on harmful substances

       Item  standard Organic impurities Wash test loss rate (%) salt(%) Clay content (%) Soft stone powder (%) Particles floated in a liquid with a specific gravity of 1.95 (5) Independence rate of lightweight aggregate aggregate (%) KASS5 I class Aggregate O 2.0 0.04 1.0 - - - Coarse aggregate - 1.0 - 0.25 - - 10 Class II Aggregate O 3.0 0.1 1.0 - - - Coarse aggregate - 1.0 - 0.25 - - 10 Class III Aggregate O 5.0 0.1 2.0 - - - Coarse aggregate - - 0.5 - - - RC Specification Aggregate O 5.0 (3.0) 0.1 1.0 - 1.0 (0.5) - Coarse aggregate - 1.0 - 0.25 50 1.0 (0.5) -

Examples of organic impurities in aggregate include fuminic acid and tannic acid. Because of the decay of vegetation in the ground, they are at high risk for inclusion in land and mountain sands. If organic impurities are contained, the coagulation and hardening of the cement will be delayed, and if the amount is increased, it may cause hardening.

Aggregates (particularly land and mountain sands) may contain bipartite such as silt and clay. This large amount of concrete increases the amount of water to obtain a slump. As a result, the initial volume shrinkage and long-term dry shrinkage increase, and cracking is likely to occur, and the strength decreases and the durability decreases.

Salinity on aggregates promotes the oxidation of rebar in concrete. Normally, while concrete retains alkalinity, the inner rebar is protected by a passivation film of ferrous hydroxide, making it difficult to rust. However, since Cl ⁻ destroys this passivation film, a local battery is formed there, which in turn converts to ferric hydroxide (red rust), which causes corrosion.

Anode: Fe → Fe ⁺⁺ + 2e

Cathode: H ₂ O + 1 / 2O ₂ + 2e →

Fe ⁺⁺ = → 2 (OH) ₂ → Fe (OH) ₂ : ferrous hydroxide

Fe (OH) ₂ + 1 / 2H ₂ O + 1 / 4O ₂ → Fe (OH) ₃ : ferric hydroxide

The relationship between salinity in fine aggregates and bar sanding is rapidly increased when salinity exceeds 0.04%. Therefore, the average aggregate is set to 0.04% salinity limit, and up to 0.1% on the premise that design and construction are specially considered.

Aggregates may contain sandstones, curbs, pumice, and clay ingots, coal and coal particles. They are generally low in specific gravity, high in water absorption and low in strength, so they can cause defects in concrete if they are mixed in high-quality aggregates.

Next, the use characteristic of various aggregates is demonstrated.

Gravel and sand in rivers are generally of good quality, but when collected in a place where the flow of the river flows, curb and wood chips are easily mixed, and they must be selected and used well because they contain dichotomy and organic impurities.

Mountain sand is generally produced for a long time, so it is weathered and contains a lot of bismuth. Mountain sand with raised seabeds may contain a lot of seashells and mica, so be careful.

The quality of sea sand is enough to be used as aggregate for concrete when salt is removed. The most problematic is the salt content. The seawater contains about 3% of salt, proportional to the sea water content of the sea sand, and 0.3-0.4% immediately after being taken in the sea. If the sea sand is left unsealed for a long time, it is considerably decontaminated by rainfall, but generally it is sprayed with water when it is loaded from the harvester.

Although crushed stone and coal sand depend on the quality of the rock, the quality of the crushed stone is usually defined as follows.

(Table 6) Quality of crushed stone

         importance           2.5 or more          Water absorption           3% or more          stability          12% less than          Wear loss          40% less than

Concrete using chain sand is as follows when compared with concrete using steel sand.

① To get the same slump, 5 ~ 10% more unit is needed.

② As the amount of fine powder decreases, the slump decreases, and the fine aggregate ratio (S / A) is lowered by the amount.

③ When material separation and bleeding of unhardened concrete increases, the amount of fine powder is increased to decrease the degree.

④ As the amount of fine powder increases, the initial time and the final time of condensation are shortened.

⑤ The compressive strength of concrete does not have a big difference if the amount of fine powder is less than 10%.

⑥ Dry shrinkage increases as the amount of fine powder increases.

⑦ If the amount of fine powder increases, the air volume decreases, so increase the air volume if necessary.

In addition, since the influence of a fine powder changes with kinds of mother rock, it is necessary to examine about each.

Blast furnace slag is obtained by using specific gravity difference in molten state simultaneously with the production of pig iron in the furnace. When molten slag is cooled outdoors, it becomes a hard mass, which is broken down into crushed coarse aggregate. In addition, quenching results in fine particles, which are used as fine aggregates. At this time, the thing quenched by water is called the wind and the thing quenched by wind is called wind. Slag crushed stone has the following characteristics when compared with steel gravel concrete due to the surface state when bubbles remain inside during cooling and crushed.

① In order to make concrete of the same construction year, the unit quantity and fine aggregate rate are slightly increased.

② The bleeding phenomenon becomes larger.

③ It may lower slump when pump is pumped.

④ The initial strength of concrete is a little high but in the long run it is almost the same.

⑤ The weight ratio is a little small, but the Young's modulus can satisfy the existing formula.

⑥ The drying shrinkage is a little smaller.

⑦ Resistance to freezing and thawing does not change.

Lightweight aggregates are classified into three types: artificial lightweight aggregates, natural lightweight aggregates, and Busan lightweight aggregates.

There are two types of artificial lightweight aggregates, prefabricated and unassembled. The non-assembled type is made by crushing and expanding the raw stone (mainly shale) to a suitable size, while the granulated type is made by crushing the raw stone once, assembling it into a suitable size and plastically expanding.

Since natural light aggregate has no volcano except Jeju Island, volcanic gravel is hardly produced. Heavy aggregates are heavy aggregates with a specific gravity of more than three, containing iron ore, pearlite (barite), and copper. They have a specific gravity of 3 to 4, which makes them concrete. In addition, high strength can be obtained, but the construction time is poor and the bleeding is large, and there are disadvantages in handling.

In addition, the mixed material is a material other than cement, water, and aggregate, and is added to impart a special quality or improve properties to mortar and concrete. Generally, admixtures are roughly classified into admixtures and admixtures. The admixture is that the volume of the admixture is not added to the volume at the time of the mixing design of concrete or mortar, and the admixture is added to the volume. Generally, the amount is used as about 1% or less of the amount of cement, the chemical characteristics are admixtures, and about 5% or more, the terms are classified as admixtures.

Such admixtures are classified as follows.

AE (air entraining agent) is an admixture used to generate independent microbubble inside the concrete, to improve the workability of the concrete and to have resistance to freeze-thawing. In general, even if the AE agent is not added, air of about 1% is contained and relatively large particle size (entrapped air) is irregularly present. In contrast, air entrained by the AE agent is uniformly distributed as a columnar phase having an entrained air particle diameter of about 10 to 100 µm. This entrained bubble acts as a ball bearing in the concrete before hardening, improving workability. In addition, in the durability of concrete after hardening, especially for freezing and thawing, the microbubbles introduced therein absorb the expansion pressure during freezing to significantly increase resistance to tissue destruction.

A water reducing agent and an AE water reducing agent are admixtures that can reduce the unit amount by dispersing cement particles in concrete, or improve workability while entraining fine bubbles, and reduce the unit amount due to the dispersing effect. Water reducing agents and AE water reducing agents can be classified into standard type, delay type and accelerated type according to the effect on the setting time of concrete. In addition, when only the AE agent is added, the water reducing effect is about 8%, or in combination with an excellent water reducing agent, or when using an AE water reducing agent, the water reducing effect is about 10-15%, and there is no decrease in strength due to the increase in air volume. Recently, it is widely used in almost all ready mixed concrete, civil engineering, and building concrete in order to increase durability and economic efficiency of concrete.

High performance sensitizers are admixtures that can significantly reduce the amount of units because they effectively disperse the cement by further improving the function of the general sensitizer and do not affect excessive air entrainment and strength degradation. High-performance water reducing agents are classified into high-density concrete water reducing agents and fluidizing agents by the method of use, but the basic performance is the same. That is, a high performance water reducing agent mainly uses water cement ratio reduction, and a fluidizing agent is used when the purpose is to produce concrete having excellent work performance as the same water cement ratio.

Shrinkage reducing agents are admixtures that have an effect of reducing shrinkage that occurs during drying, and are mainly used for reducing or preventing mortars and cracks in concrete, improving fillability, preventing peeling, and the like. Shrinkage reducing agent (organic admixture) is a form that reduces the shrinkage by reducing the capillary tension during drying by dissolving in capillary water, which dominates the shrinkage without causing an expansion reaction. Cement pastes with higher water-cement ratios shrink more, but aggregates act to alleviate dry shrinkage in mortar and concrete.

The regulator cement begins to hydrate as soon as it comes into contact with water, gradually loses its fluidity and begins to harden, showing strength over time. This process is called coagulation hardening. A coagulation hardening time control agent is a mixed material used for the purpose of accelerating or delaying mortar or concrete's setting time or initial hydration rate by affecting the hydration reaction of cement. These include quick payments, rapid economic (re), accelerating materials, retardants, and super-delays.

Fasteners and economics are admixtures that make the concrete harden and harden very quickly. This quick admixture is added for the purpose of preventing water or rainwater during the construction of the emergency repair tunnel.

Accelerators and retarders are admixtures used for the purpose of reducing the effects of mortar or concrete material temperature or ambient temperature. Super delay agents are used to improve the construction and quality of concrete by arbitrarily delaying the setting time.

Foaming agents are mainly used to reduce the weight of concrete. Most of these applications are made of foamed concrete, mainly based on ALC (Autoclaved Light-weight Concrete) based on the spread of high-rise construction and the increasing use of precast products. Lightweight precast products have been in the spotlight as building materials having excellent properties such as light weight and heat insulation, and are increasing in demand.

In addition, admixtures are classified as follows.

In the iron works of the blast furnace method, slag, which is mainly composed of aluminosilicate, is produced at the same time as pig iron. Granulated balst furnace slag that is quenched by water, air, etc. into granular hot slag is called granulated balst furnace slag, and the crystal state and quality of the product vary depending on the cooling treatment method. , Quench slag, and the like. The uses of these products are shown in Table 7.

Table 7 Uses of Slag

Kinds Usage Slow cooling slag Road use (surface, subgrade, filling), aggregate for concrete, port material, ground improvement material, cement krinka raw material, silicate fertilizer, etc. Quenched Slag (Hydraulic Slag, Granular Slag) For blast furnace cement (cement mixture), cement clinker raw materials, concrete mixtures Lightweight aerated concrete raw materials (ALC), ground improvement materials, fine aggregates for concrete, fine aggregates for asphalt, roadbed stability treatment, lime silicate fertilizer, port materials, civil engineering Semi-cold cold slag (expansion slag) Lightweight Concrete Aggregate, Lightweight Landfill, Other Insulation

The chemical composition of the blast furnace slag powder is represented as a chemical component containing gypsum added as needed. The blast furnace slag powder to which gypsum was added also has high CaO content and a base.

Table 8 Chemical Composition Range of Blast Furnace Slag (wt%)

SiO ₂ Al ₂ O ₃ CaO MgO FeO MnO S TiO ₂ Na ₂ O K ₂ O 31.2 to 36.7 12.1 to 16.3 38.0-45.0 4.7-7.4 0.06-1.00 0.21 to 1.42 0.49 to 1.51 0.38-1.99 0.16 to 0.42 0.22 to 0.56

In the physical properties of the slag, the specific gravity of the crushed slag is 1.89-2.77, but the range is wide. However, the specific gravity of the blast furnace slag powder pulverized to 74㎛ or less has a range of 2.85-2.94 and averages about 2.90. This value is 8% less than the specific gravity of Portland cement (3.15). The initial strength of concrete using blast furnace slag powder of 3,000-4,500 cm ² / g powder is smaller than that of Portland cement concrete, and this tendency is more pronounced with higher slag substitution rate or smaller water cement ratio.

As described above, the fly ash is one of the admixtures representing the pozzolanic system as coal ash produced by combustion boilers such as thermal power plants. The chemical composition varies depending on the composition of the raw coal, but is generally the highest in terms of SiO ₂ 60%, Al ₂ O ₃ 25%, Fe ₂ O ₃ , carbon (C) and the like compared to slag It is characterized by low CaO and abundant SiO ₂ and Al ₂ O ₃ . Fly ash itself is not hydrophobic, but slowly reacts with calcium hydroxide produced during cement hydration at room temperature to produce insoluble stable calcium silicate hydrate. The benefits of mixing fly ash with concrete include: ① improved fluidity, ② improved long-term strength, ③ reduced heat of hydration, ④ suppressed alkali aggregate reactions, ⑤ resistance to sulphate, and ⑥ improved watertightness.

In addition, silica fume is a generic term for by-products generated by floating in exhaust gas when silicon alloys such as silicon and ferrosilicon are manufactured in an electric arc furnace, and are used as raw materials for silicon alloys such as silica, coal, wood chips, iron powder and reducing agents. Coke is introduced into an electric furnace to produce ferrosilicon at a high temperature of about 2,000 ° C. At this time, the intermediate product SiO is gasified, which is oxidized by air to SiO ₂ and condensed to produce ultrafine particles. The generated ultrafine particles are recovered by using an electrostatic precipitator.

Table 9 shows the chemical composition of silica fume produced by the production of the silicon alloy which is a source of silica fume. More than 80% of the main components are composed of SiO ₂ , except for silica fumes from CaSi and SiMn, which are not suitable as pozzolanic materials.

Table 9 Chemical composition of silica fume produced by the production of various silicon alloys

Si FeSi-90% FeSi-75% White silica fume FeSi-75% FeSi-50% FeCrSi CaSi SiMn SiO ₂ 94-98 90-96 86-90 90 84.1 83 53.7 19 Fe ₂ O ₃ 0.02-0.15 0.2-0.8 0.3-5.0 2.9 8.0 1.0 0.7 3.9 Al ₂ O ₃ 0.1-0.4 0.5-3.0 0.2-1.7 1.0 0.8 2.5 0.9 5.5 CaO 0.1-0.3 0.1-0.5 0.2-0.5 0.1 1.0 0.8 23.2 12.4 MgO 0.2-0.9 0.5-1.5 1.0-3.5 0.2 0.8 7.0 3.3 2.4 Na ₂ O 0.1-0.4 0.2-0.7 0.3-1.8 0.9 - 1.0 0.6 1.1 K ₂ O 0.2-0.7 0.4-1.0 0.5-3.5 1.3 - .18 2.4 8.7 C 0.2-1.3 0.5-1.4 0.8-2.3 0.6 1.8 1.6 3.4 3.7 S 0.1-0.3 0.1-0.4 0.2-0.4 0.1 0 - - - MnO 0.1 0.1-0.2 0.02 - 0 0.2 - 28.5 L.O.I 0.8-1.5 0.7-2.5 2.0-4.0 - 3.9 2.2 7.9 7.5

Silica fume is composed of about 90% or more of spherical shape, particle size is less than 1㎛, average particle size is about 0.1㎛, specific surface area is about 20m ² / g, specific gravity is about 2.1-2.2, unit weight is 259-300 kg / m ³ . It is also mainly amorphous but contains a-SiO ₂ and MgFe ₂ O ₄ , and its content also shows a considerable difference.

Silica fume is the main component and the pozzolanic reaction at an early age due to the CSH is generated reacts with the Ca (OH) ₂ as an amorphous SiO ₂ and the ultra fine powder.

As the mixing rate of silica fume increases, the compressive strength increases, but generally, the mixing rate is about 5-15%.

In addition, as a silica-based admixture, rice husks are emitted about 200 kg per tonne of rice, and when burned, rice hulls weighing about 40 kg are obtained. Chaff has very good pozzolanic reactivity because it consists mainly of amorphous silica and has a very large surface area (50-60m ² / g). The amount of condensation increases when the rice hull is mixed with cement, and the flow value decreases at the same water-cement ratio. In addition, when used in high-strength mass concrete, the effect of suppressing the heat of hydration is great, and when about 10% is added to concrete, there is an effect of reducing the alkali-silica expansion reaction.

Natural pozzolanic is obtained from igneous rock minerals such as volcanic ash. Volcanic ash, tuff, siliceous silica, diatomaceous earth, etc. are natural pozzolans. Depending on the main components, they are classified as silica alumina and silica, or as volcanic glasses, volcanic tuffs, diatomateous earth, Sometimes classified as calcined clay.

Volcanic glass (volcanic glasses) is a silica-alumina volcanic glass that has magma from volcanic eruption and quenched in the air, resulting in a porous structure with a large amorphous surface area. This is the factor that increases pozzolanic reactivity.

As a clay pozzolan, volcanic glass can be used without additional heat treatment to enhance pozzolanic properties. However, clay pozzolan does not harden well due to low pozzolanic reactivity unless the heat treatment destroys the crystal structure of the clay mineral. Therefore, it is possible to increase pozalan reactivity by calcining at about 600-900 ° C. to form a crystalline structure or irregular silica-alumina structure.

Diatomaceous earth is a siliceous sedimentary rock formed by sedimentation of single cell-containing fluids called diatoms on the sea floor, lakes and swamps. Diatomaceous earth has a very good reactivity with lime, but due to its special microstructure, a large quantity is required when mixing with concrete, which has a detrimental effect on the durability and strength of concrete. In addition, since the clay component mixed with diatomaceous earth is a factor that inhibits the pozzolanic reaction, it is also good to heat-treat before using it as a miscible material.

The effects of natural pozzolanic addition on concrete properties include ① improvement of workability, ② reduction of heat of hydration, ③ improvement of long-term strength, ④ improvement of chemical resistance such as sulfate resistance, ⑤ improvement of water tightness, and ⑥ inhibition of alkali aggregate reaction.

In addition, in Pozzolanic Cement, Pozzolan does not itself harden by reacting with water, but hardens by reacting with lime (Ca (OH) ₂ ) in the presence of water at room temperature. It is defined as highly reactive silica (Silica) or silicate (Silicate). The scheme is shown below.

CH + S + H → C-S-H (Calcium Silica Hydrate)

(C: CaO, H: H ₂ O, S: SiO ₂ )

They should be high in SiO ₂ and high in soluble silica and soluble alumina which are easy to combine with Ca (OH) ₂ as active. The higher the alumina, the higher the initial strength, and the higher the soluble silica, the higher the long-term strength.

In addition to soluble SiO ₂ and Al ₂ O ₃ , CaO, Fe ₂ O _3, etc. are contained, and it is not known whether they are hydrated, but it is known to contribute to hydration.

Substances having pozzolanic activity include natural acids such as volcanic ash and tuff and artificial ones such as fly ash. One of the natural pozzolanic materials is diatomite. Diatomaceous earth is a shell of diatom and is deposited on the bottom of the sea or lake. It is a soft rock or soil mass composed of more than 95% of silica, and has very small pores, so it absorbs about 4 times its weight. Absorbs enough liquid.

The essence of the pozzolanic reaction is to produce silica / aluminate hydrates in which the free CaO, which is produced when the cement is hydrated, is contained in pozzolanic. Therefore, the formation of the hydrate has the property of showing the high strength of the cement mortar.

Usually, in Portland cement hydration, Ca (OH) ₂ and Ettringite are produced at the beginning of hydration, followed by CSH. When gypsum is consumed, C ₃ AH ₆ (C ₃ FH ₆ ) reacts with CH to produce C ₄ (A, F) H ₁₃ , and AF _t (Al-Fe-Trisulfate) is AFm (Al-Fe-Mona sulfate) Changes to The main hydration reactions are shown in Table 10.

Table 10 Hydration of Cement

Hydration Step Hydration reaction StageⅠ 3CaAl ₂ O ₃ + 3CaSO ₄ + 32H ₂ O → 3CaOAl ₂ O ₃ · 3H ₂ O (Ettringgite) S-tageⅡ 2 (3CaSiO ₂ ) + 6H ₂ O → 3CaO · 2SiO ₂ · 3H ₂ O (CSH) + 3Ca (OH) ₂ Tobermorite-like phase (2CaSiO ₂ ) + 4H ₂ O → 3CaO · 2SiO ₂ · 3H ₂ O ( CSH) + Ca (OH) ₂ StageⅢ 3CaOAl ₂ O ₃ + Ca (OH) ₂ + 12H ₂ O → 4CaOAl ₂ O ₃ 13 H ₂ O Stage IV _{2 (3CaO · Al 2 O 3} ) + 3CaO · Al 2 O 3 · 3CaSO 4 · 32H 2 O + 4H 2 O → (3CaO · Al 2 O 3 · CaSO 4 · 12H 2 O)

In this continuous chemical reaction, the concentration of the hydrate gel becomes thicker and the gel particles harden over time. As time passes again, the formation of gel increases and the cement particles are filled to cure. The hydration of Portland cement is not the same as the overall hydration of each cement compound, but the trend is similar and further complicated by their interaction. Here, the ettringite produced during the initial hydration of cement is known to be very important not only for the immobilization of heavy metal ions but also for elution.

The pozzolanic materials include SiO ₂ , Al ₂ O ₃ , CaO, Fe ₂ O _3, etc. Among them, the components contributing to the activity are SiO ₂ , AlO ₃ , which are Ca (OH) produced when they are hydrated with cement. Reaction with ₂ ) has the effect of increasing the strength of concrete and the general reaction is as follows.

3CaOSiO ₂ + (n + 2) H ₂ O = 3CaOSiO ₂ H ₂ O + 2Ca (OH) ₂

2CaOSiO ₂ + (n + 1) H ₂ O = 3CaOSiO ₂ H ₂ O + Ca (OH) ₂

In addition to these free Ca (OH) ₂ reactions that occur when pozzolanic materials containing fusible silica and alumina

xCa (OH) ₂ + ySiO ₂ mH ₂ O → xCaO ySiO ₂ + nH ₂ O

_{xCa (OH) 2 + yAl 2} O 3 · mH 2 O → xCaO · yAl 2 O 3 + nH 2 O

As the above occurs, hydrates of calcium silica and calcium aluminate are produced to prevent elution of Ca (OH) ₂ and to obtain a pozzolanic effect.

In addition, the characteristics of concrete using pozzolanics generally improve workability, reduce bleeding and material separation, and reduce calorific value by alleviating heat of hydration. In addition, durability, watertightness and chemical resistance to seawater are increased, and the unit strength is slowed but the long-term strength is longer or higher than that of general concrete. Bottom ash or fly ash is applied to concrete.

Pozzolanic cement refers to a cement which is mixed with general cement (OPC: Ordinary Portland Cement) as a pozzolanic material and obtains long-term hydration through reaction with free CaO present in the cement itself. As mentioned above, most pozzolanic materials include fly ash, diatomaceous earth, small clays, slag powder, volcanic ash and the like. These materials are not curable in themselves, but are materials capable of producing and curing a stable insoluble compound (Calcium Silica Hydrate) by reacting with Ca (OH) ₂ at room temperature in the presence of water through the following reactivity.

CaO + SiO ₂ + H ₂ O → 3CaO · 2SiO ₂ · 3H ₂ O (Calcium Silicate Hydrate)

Next, the development of cement mortar will be described as a preliminary step for developing high performance concrete according to the present invention.

As shown in Table 11, the chemical analysis of bottom ash and fly ash was compared. The amount of SiO ₂ contained in the bottom ash or fly ash is almost the same, but the amount of Al ₂ O ₃ and Fe ₂ O _{3 in the} bottom ash is much lower than that of the fly ash. However, the CaO content is higher in the bottom ash, so the bottom ash will be more hygroscopic on cement mortar.

Table 11 Chemical Analysis

In the present invention, in order to replace ordinary sand (Ordinary Beach Sand: hereinafter referred to as OBS), the bottom ash has been discarded in Ash Pond for a long time in Boryeong thermal power plant, most of them are collected in a clinker state and sifted after grinding process. Low (-30 # + 50 #) bottom ash sand (Bottom Ash Sand: hereinafter referred to as BAS).

In addition, in the present invention, a domestic L company, which is commercially available, is used as one type of ordinary Portland Cement (hereinafter referred to as OPC). Tables 12 and 13 show the chemical composition and physical properties of the cement.

Table 12 Cement Chemical Analysis

division SiO ₂ Al ₂ O ₃ Fe ₂ O ₃ CaO MgO Na ₂ O K ₂ O SO ₃ TiO ₂ LOI Sum Content (wt%) 20.5 6.4 2.9 61.4 3.0 1.2 0.8 2.1 0.4 0.8 99.5

Table 13 Cement Physical Properties

Blister (㎠ / g) Set time Concentration (w / c) Mortar Flow (mm) Start (min) End (hr: min) 3403 193 6:10 23.9% 198

Next, the pozzolanic raw materials that can be supplied in Korea as the admixture (Pozzolan Admixture) used in the present invention are shown in Table 14. It is usually a fine powder that passes through -320 #.

Table 14 Types of Admixtures

division Contents Statue    Contec N          Company H Special Blend Pozzolan  Gray powder    Contec S          Company H Special Blend Pozzolan  Gray powder    D-650          Company H Diatom Calcined at 650 ℃  Apricot powder    SP-600          Company H Special Blend Pozzolan  White powder    P-800          Y company Ordinary Pozzolan  Light gray powder    ∑1000          Company D Pozzolan  White powder

  The fluidizing agent used in the present invention is shown in Table 15.

Table 15 Types of Glidants

division Contents shape Power Con-100 K Naphtalene Sulphonate Sodium Salt Products Dark brown liquid Polycarbonic acid Company D Poly Carbone Acid Product Light yellow liquid Sodium Gluconate S company imported products Pale yellow liquid Flow 2000S Product composed mainly of Napthalene formaldehyde Sulphonate and High Molecular Weight Polymer of Company D. Light yellow liquid

Next, the compounding ratio used in the present invention was investigated.

First, as shown in Table 16, the change of physical properties of cement mortar was investigated by replacing OBS with BAS.

Table 16 Formulation Ratio

Sample N ^o . material(%) CTL BCM-1              OPC OBS BAS          29.0 71.0-         29.0-71.0 Total Power Con-100 CaCl ₂         100 0.5 0.5        100 0.5 0.5      Flow (mm) (142 ± 10) Water / Cement (%)          48.5        107.8 Compressive strength (kg / cm ² ) 7 days underwater curing 310 77 28 days underwater curing 431 102

          CTL: Control Mix

        BCM: Bottom Ash Cement Mortar

        OPC: Ordinary Portland Cement

        OBS: Ordinary Beach Sand

        SAND: Ordinary Beach Sand

        BAS: Bottom Ash Sand

Next, as shown in Table 7, the change in the physical properties of the cement mortar when the BAS was gradually reduced, while the amount compensated with cement by decreasing the amount.

Table 17 Formulation Ratio

Sample N ^o .Material (%) BCM-1 BCM-2 BCM-3 BCM-4 BCM-5          OPC BAS BAS BAS BAS BAS    29.0 71.0----    31.9-68.1---    34.8--65.2--    40.6---59.4-    52.2----47.8 Sum 100 100 100 100 100

OPC Co., Ltd .: Ordinary Portland Cement

     BCM: Bottom Ash Cement Mortar

     BAS: Bottom Ash Sand

Next, as shown in Table 18, the physical properties of the BAS cement mortar with the addition of pozzolanic admixtures were investigated.

Table 18 Formulation Ratio

Sample N ^o .Material (%) BCM-5 BCM-6 BCM-7 BCM-8 BCM-9 BCM-10 BCM-11      OPC BAS PA-I PA-II PA-III PA-IV PA-V PA-VI   52.2 47.8------   47.0 47.8 5.2-----   47.0 47.8-5.2----   47.0 47.8--5.2---   47.0 47.8---5.2--   47.0 47.8----5.2-   47.0 47.8-----5.2 Sum 100 100 100 100 100 100 100

  PA-I: Pozzolan Admixture (Contec N: German Made Pozzolan)

         PA-II: Pozzolan Admixture (Contec S: German Made Pozzolan)

         PA-III: Pozzolan Admixture (H Company Specially Calcined Diatom)

         PA-IV: Pozzolan Admixture (H Company Specially Blend Pozzolan)

         PA-V: Pozzolan Admixture (Y Company's Ordinary Fly Ash Pozzolan)

         PA-VI: Pozzolan Admixture (∑1000: Y company Pozzolanic Type

                 Material)

Then, as shown in Table 19, the physical properties of the BAS cement mortar with the addition of various kinds of fluidizing agents were investigated.

Table 19 Formulation Ratio

Sample N ^o .Material (%) BAS-12 BAS-13 BAS-14 12-1 12-2 12-3 13-1 13-2 13-3 14-1 14-2 14-3        OPC BAS PA-III PA-IV  52.2 47.8--  52.2 47.8--  52.2 47.8--  47.0 47.8 5.2-  47.0 47.8 5.2-  47.0 47.8 5.2-  47.0 47.8-5.2  47.0 47.8-5.2  47.0 47.8-5.2 Sum 100 100 100 100 100 100 100 100 100

PCA: Poly Carbonate Acid

     SG: Sodium Gluconate

     FS: Flow 2000S

1 shows a manufacturing process of the specimen according to the present invention. 1 is a progress diagram of an experiment for carrying out a composition of high strength cement mortar using a bottom ash according to the present invention and a method for producing the same.

All samples were weighed by weight percentage, and the mixture was mixed for 30 seconds at a first speed after mixing for 30 seconds at a second speed, and then left for 90 seconds according to Korean Industrial Standard KS L 5109. While standing, the mortar on the sides of the container was scraped into the batch, and the lid was placed on the container to prevent evaporation of water, followed by mixing for 2 seconds and 60 seconds. Using a flow table, the mortar having a satisfactory flow value was put back into a mixing vessel, mixed for 15 seconds, and a cube was formed. Compaction for the production of cube molding is made by using a compaction rod to make six cubes on a sample with four wheels of uniform pressure for about 10 seconds and then hitting the cube corners with a rubber hammer so that the mortar is uniformly placed on the cube. It was.

After producing cubes, the samples were dried in a 22 ℃ dryer for 24 hours, demolded, and placed in a container with water of 23 ± 2 ℃. The compressive strength was measured after 7 days and 28 days of curing in water.

In the measuring method used in the present invention, the flow and compressive strength of cement mortar were in accordance with KS L 5105 (Test method for compressive strength of hydraulic cement mortar). For flow measurement, use the flow table and the frame in accordance with KS L 5111 (cement test flow table), drop it to the height of 1.27cm for 25 times in 15 seconds, lift the frame at right angles, and measure the four diameters at approximately equal intervals. Use an average of one flow value (110 ± 10 mm). In the present invention, since the fluidity is not good when the standard yarn is replaced by the bottom ash, the experiment was fixed to the flow value of 142 ± 10 mm.

In addition, in the mineral analysis used in the present invention, XRD (X-Ray Diffraction) was measured by M03XHF type equipment from MAC Science, France, the measurement conditions are shown in Table 20.

Table 20 X-ray Diffraction Parameters

radiation CuKα wavelength 0.15404 nm Voltage 40.0㎸ electric current 30.0 ㎃ Step width 0.020deg Scanning speed 2.000deg / min Slit 1.0 deg. (D.S.) 1.00 deg. (S.S) 0.30 nm (R.S.) Scanning area 5 ° <2θ <70 °

SEM (Scanning Electron Micrograph) was observed at 20㎸, 2,000 times and 5,000 times using SEM ABT-32 of Topcon Japan.

Pore Size Distribution (Pore Size Distribution) used Mercury Intrusion Porosimetry (Auto Pore IV 9500) from Micromeritics.

The porosity changes in the sample was given by measuring each sample of dry weight (W _1), catching the water weight (W _2), PO check gun weight (W ₃₎ to the following equation.

Next, the change of physical properties of cement mortar replacing OBS with BAS was investigated.

2 shows CTL and sample No. when flow 142 ± 10. It is a graph of change in W / C (%) of BCM-1, and FIG. 3 shows CTL and sample No. Compressive strength change graph of BCM-1, Figure 4 is a CTL and a sample No. This is a graph of the change in curing strength versus compressive strength of BCM-1. Table 21 is a table showing the physical relationship.

As can be seen from Table 21 and FIGS. 2 to 4, when BAS was substituted for cement mortar (CTL) using OPC and general sand, the amount of additive required in CTL to maintain flow 142 ± 10 (48.5%) 107.8% is required to add more than 122% more than).

In other words, BAS has absorbency of about 4-10% or more than standard yarn. In addition, in terms of compressive strength, the 7-day strength of CTL mixing was higher than that of 310 kg / cm ² . BCM-1 showed 77 kg / cm ² of compressive strength as low as 400%. Underwater curing 28-day compressive strength was also 431 kg / cm ² CTL mixing compared to sample No. BCM-1 was 102 kg / cm ² expressed about 400% lower. As a result, it was not possible to replace BAS with a standard company, and when BAS was replaced, an appropriate amount of BAS should be derived.

Table 21 Property Changes

Sample N ^o .Material (%) CTL BCM-1              OPC OBS BAS         29.0 71.0-        29.0-71.0 Total Power Con-100 CaCl ₂        100          0.5 0.5       100         0.5 0.5           Flow (mm) Water / Cement (%)        142.4 48.5       136.0 107.8 Compressive strength (kg / cm ² ) 7 days underwater curing 310 77 Underwater Curing 28 Days 431 102

          CTL: Control Mix

        BCM: Bottom Ash Cement Mortar

        OPC: Ordinary Portland Cement

        OBS: Ordinary Beach Sand

        BAS: Bottom Ash Sand

        Powercon-100: 0.5% of cement

CaCl ₂ : 0.5% in amount of cement

Next, the change of physical properties of cement mortar with BAS substitution rate was investigated.

5 is a graph of change in W / C (%) according to BAS substitution rate when flow 142 ± 10, FIG. 6 is a graph of change in compressive strength when BAS is replaced with general yarn, and FIG. 7 is compression of BCM versus BCM Intensity change graph. Table 22 is a table showing the physical property results.

In the CTL mixture, when ordinary yarns were replaced with BAS and compensated by OPC, the curing time and compressive strength of 28 days were replaced by BAS as shown in Table 22 and FIGS. 5 to 7. When it is equal to or higher than the compressive strength of the CTL mixture, the replacement rate of BAS is about 54%, and the amount of OPC required is 46%. Sample No. in cement mortar replacing ordinary sand with BAS BCM-5 has a compressive strength of 534 kg / cm ^{2 in water} and 600 kg / cm ² in 28 days, which is 72% (7 days) and 42% (28 days) higher than CTL mixing, respectively. Therefore, in order to manufacture high strength cement mortar using at least BAS, sample No. BCM-5 is the standard.

(Table 22) Property results

Sample N ^o .Material (%) BCM-1 BCM-2 BCM-3 BCM-4 BCM-5             OPC BAS BAS BAS BAS BAS    29.0 71.0----    31.9-68.1---    34.8--65.2--    40.6---59.4-    52.2----47.8 Total Power Con-100-100 CaCl ₂   100     0.5 0.5   100     0.5 0.5   100     0.5 0.5   100     0.5 0.5   100     0.5 0.5 Flow (mm) (142 ± 10) Water / Cement (%) 107.8 96.2 81.3 64.4 36.3 Compressive strength (kg / cm ² ) 7 days underwater curing 77 97 165 257 534 Underwater Curing 28 Days 102 141 239 344 620

OPC Co., Ltd .: Ordinary Portland Cement

     BCM: Bottom Ash Cement Mortar

     BAS: Bottom Ash Sand

     Powercon-100: 0.5% on cement volume

CaCl ₂ : 0.5% on amount of cement

Next, the change of physical properties of BAS cement mortar with the addition of pozzolanic admixture was investigated.

FIG. 8 is a graph showing a change in W / C (%) of BCM cement mortar with admixtures, FIG. 9 is a graph of change in compressive strength of BCM cement mortar with admixtures, and FIG. 10 is a graph of BCM cement mortar with admixtures. Compressive strength change graph according to curing days. Table 23 is a table showing the physical property results.

Various types of pozzolanic additives were used as sample No. The compressive strength change when added to BCM-5 is shown in Table 23 and FIGS. 8 to 10. First, when comparing only the 7-day compressive strength of the underwater curing, their strength does not appear to be greatly improved. At the same time, even in 28 days of compressive strength, it is not much improved, but at least sample No. BCM-8 and Sample No. BCM-9 is sample No. It can be seen that about 5-20% (if 28) is improved over BCM-5.

However, Sample No. BCM-8 and 9 are sample No. It was found that the higher the amount of water added than the BCM-5, the better the compressive strength would be.

Table 23. Property Results

Sample N ^o .Material (%) BCM-5 BCM-6 BCM-7 BCM-8 BCM-9 BCM-10 BCM-11          OPC BAS PA-I PA-II PA-III PA-IV PA-V PA-VI   52.2 47.8------   47.0 47.8 5.2-----   47.0 47.8-5.2----   47.0 47.8--5.2---   47.0 47.8---5.2--   47.0 47.8----5.2-   47.0 47.8-----5.2 Total Power Con-100 CaCl ₂  100    0.5 0.5  100    0.5 0.5  100    0.5 0.5  100    0.5 0.5  100    0.5 0.5  100    0.5 0.5  100    0.5 0.5        Flow (mm) Water / Cement (%)  132.5 36.3  132.4 38.5  131.4 42.5  135.8 43.6  132.6 42.5  132.5 43.6  135.4 45.4 Compressive strength (kg / cm ² ) 7 days underwater curing 534 563 488 546 583 480 510 Underwater Curing 28 Days 620 645 545 659 680 648 626

PA-I: Pozzolan Admixture (Contec N: German Made Pozzolan)

      PA-II: Pozzolan Admixture (Contec S: German Made Pozzolan)

      PA-III: Pozzolan Admixture (H Company Specially Prepared Calcined

               Diatom)

      PA-IV: Pozzolan Admixture (H Company Specially Blend Pozzolan)

      PA-V: Pozzolan Admixture (Y Company's Ordinary Fly Ash Pozzolan)

      PA-VI: Pozzolan Admixture (∑1000: Y company Pozzolanic Type

              Material)

      Powercon-100: 0.5% on cement volume

CaCl ₂ : 0.5% on amount of cement

Next, the change of physical properties of BAS cement mortar with fluidizing agent was investigated.

FIG. 11 is a graph showing a change in W / C (%) when the fluidizing agent is added to the BCM cement mortar, FIG. 12 is a graph showing a change in compressive strength when the fluidizing agent is added to the BCM cement mortar, and FIG. Compressive strength change graph when the fluidizing agent is added to BCM-12, Figure 14 is a sample No. Compressive strength change graph when the fluidizing agent is added to BCM-13, Figure 15 is a sample No. Compressive strength change graph when fluidizing agent is added to BCM-14. Table 24 is a table showing the physical property results.

In Table 24 and FIGS. 11 to 15, the cement mortar having the most effective increase in compressive strength in the third step was sample no. BCM-6, Sample No. BCM-8. However, sample No. BCM-6 is a German import additive, sample No. The compressive strength was almost the same as that of BCM-8, and no further experiments were conducted. Therefore, sample No. BCM-8 and Sample No. According to the results of the compressive strength after adding the high performance fluidizing agent to the BCM-9, the high performance fluidizing agent shows a significant improvement in the compressive strength. Among them, PCA (Poly Carbonate Acid) fluidizing agent was the most effective, followed by Powercon-100.

At this time, the cement mortar with the best compressive strength was improved. As the BCM-13-2, and underwater curing 7 days compressive strength of 584kg / cm ^2, the water curing 28 day compressive strength is shown here to 710kg / cm ^2, BAS cement mortar, at least for preparing a high-strength concrete electric pole or a file for Was enough.

(Table 24) Property results

Sample N ^o .Material (%) BCM-12 BCM-13 BCM-14 12-1 12-2 12-3 13-1 13-2 13-3 14-1 14-2 14-3           OPC BAS PA-III PA-IV  52.2 47.8--  52.2 47.8--  52.2 47.8--  47.0 47.8 5.2-  47.0 47.8 5.2-  47.0 47.8 5.2-  47.0 47.8-5.2  47.0 47.8-5.2  47.0 47.8-5.2 Total Power Con-100 PCA SG + FS (1: 1) CaCl ₂ 100   0.5--0.5 100   -0.5-0.5 100   --0.5 0.5 100   0.5--0.5 100   -0.5-0.5 100   --0.5 0.5 100   0.5--0.5 100   -0.5-0.5 100   --0.5 0.5        Flow (mm) Water / Cement (%) 145.5 40.3 136.4 34.0 131.2 40.2 133.6 40.4 142.3 38.5 130.9 43.8 133.6 38.8 139.5 43.1 136.2 39.0 Compressive strength (kg / cm ² ) 7 days underwater curing 421 572 430 530 584 525 583 520 547 Underwater Curing 28 Days 564 693 627 632 710 650 681 635 621

 PCA: Poly Carbonate Acid

       SG: Sodium Gluconate

       FS: Flow 2000S

       PCA: 0.5% on cement volume

       SG + FS: 0.5% on cement volume

CaCl ₂ : 0.5% on amount of cement

Next, XRD analysis results for determining the state of hydration reaction to BAS cement mortar according to the general company and the present invention are shown in FIG. 16. 16 is a view showing the XRD pattern of BAS cement mortar according to the general yarn and the present invention.

In particular, the sample No. showing the highest compressive strength among BAS cement mortars. BCM-5 was selected. In the case of CTL, quartz peaks appeared strongly around 26.6 ° C. In the case of BCM-5, it can be seen that the peaks of C ₂ SH (Dicalcium Silicate Hydrate) and Ca (OH) ₂ are significantly reduced compared to the quartz peak of CTL. The slowing of the quartz peak is due to the reaction with Ca (OH) ₂ to produce C ₂ SH, which is why Ca (OH) ₂ development contains a lot of cement. Sample No. The increase in compressive strength in BCM-5 is also considered to be related to excitation. The formation of C ₂ SH is produced by the hydration of C ₃ S (3CaO · SiO ₂ ) and C ₂ S (2CaO · SiO ₂ ), which occupy the largest amount in cement, as the cement hardens. Initially, the strength of cement is mostly C ₃ S, but after 28 days, C ₃ S and C ₂ S contribute almost half of the strength. K ₂ Mg ₂ (SO ₄ ) ₃ does not significantly affect the development of compressive strength.

In addition, CTL mixing and Sample No. according to the present invention. A comparison on SEM of the BCM-5 mix can be seen in FIGS. 17 and 18. FIG. 17 is a SEM observation diagram of a general yarn and BAS cement mortar according to the present invention at a magnification 2000, and FIG. 18 is a SEM observation view of a general yarn and BAS cement mortar according to the present invention at a magnification 5000.

First, sample No. In BCM-5, more Fiber Crystalline, which is thought to be C ₂ SH, is produced than CTL mixture, and at the same time, Sample No. BCM-5 is better developed. In addition, the sand fed by BAS is evenly distributed so that the overall compact and stable structure can be observed. This fact is not related to the results shown in XRD and the development of compressive strength.

In addition, PSD differences in CTL mixing and BCM mixing according to the present invention can be seen in FIGS. 19 and 20. FIG. 19 is a diagram illustrating PSD distribution of general yarns and BAS cement mortar according to the present invention, and FIG. 20 is a diagram illustrating PSD cumulative distribution of BAS cement mortar according to the present invention.

In the CTL mixture, the pores of about 7,000-12,000 nm are mainly distributed, while the sample No. BCM-5 has a large distribution of 70-80 nm pores but in volume it is much smaller than CTL mixing. In terms of their cumulative pore volume, 100-12,000 nm is mainly seen in the CTL, and in the BCM mixing according to the present invention, the volume is distributed so small that it cannot be compared. This phenomenon can be seen as a matrix in which a large amount of cement evenly and tightly surrounds the BAS. This phenomenon is due to the sample No. BCM-5 mixing is also a factor that can lead to higher compressive strength.

Next, a comparison of the BCM according to the present invention to which ordinary sand cement mortar and pozzolan are added will be described.

Sample No. showing relatively high compressive strength BCM-8 and Sample No. BCM-9 was compared in CTL mixing and XRD. FIG. 21 is a diagram showing an XRD pattern when admixture is added to BCM cement mortar. FIG.

Sample No. BCM-8 and Sample No. The XRD pattern of BCM-9 was sample No. It was not significantly different from BCM-5. At the same time, sample No. It did not change as much as BCM-5. Sample No. BCM-8 is sample No. It is unusual that the Ca (OH) ₂ peak is slower than BCM-5. This slowing phenomenon was observed in sample No. Pozzolanic acid added to BCM-8 was sample no. It is more active in hydration than pozolan added to BCM-9.

In addition, the comparison of the BCM according to the present invention to which the ordinary yarn cement mortar and the pozolan were added can be seen in the SEM image of the CTL mixture and the sample according to the present invention in FIGS. 22 and 23. FIG. 22 is an SEM observation diagram in which the admixture is added to the BCM cement mortar at a magnification of 2000. FIG. 23 is an SEM observation diagram in which the admixture is added to the BCM cement mortar at a magnification of 5000.

Sample No. with Pozolan added rather than CTM mixing BCM-8 and Sample No. BCM-9 blend is more downy tissue. At the same time, sample No. BCM-8 is sample No. It shows a more compact structure than BCM-9, and the fiber crystals were obtained using sample No. Better developed in BCM-9. For this reason, Sample No. BCM-8 and Sample No. BCM-9 has higher compressive strength than CTL mixing.

In addition, the comparison of the pore distribution of the CTL mixture and the sample according to the present invention with respect to the comparison of the BCM according to the present invention to which ordinary sand cement mortar and pozzolan were added can be seen in FIGS. 24 and 25. FIG. 23 is a diagram illustrating a PSD distribution in which a mixed material is added to a BCM cement mortar, and FIG. 24 is a diagram illustrating a PSD cumulative distribution in which a mixed material is added to a BCM cement mortar.

Sample No. with Pozolan added BCM-8 and Sample No. The pore distribution of BCM-9 is not very different. However, when they were compared with CTL mixing, Sample No. BCM-8 and Sample No. The BCM-9 shows much lower voids. In particular, sample No. BCM-8 and Sample No. BCM-9 is mainly interspersed with 70-100nm pores, but CTL shows high porosity of 9,200-12,000nm, so it is not unusual that CTL mixture showing such high porosity shows low compressive strength.

Next, sample No. to which pozzolan was added. The addition of a high fluidizing agent (PCA) of BCM-5 mortar will be described with reference to FIG. 26.

FIG. 26 is a diagram showing an XRD pattern of BCM cement mortar to which a glidant is added. FIG.

Sample No. with Pozolan added Sample No. to which BCM-5 and a high fluidizing agent (PCA) were added. BCM-13-2 and Sample No. The change in the XRD peak shown in BCM-14-1 is not significantly different as shown in FIG. 24. However, if the change is unusual, Ca (OH) ₂ peak is the sample No. In sample BCM-13-2 and sample BCM14-1, sample No. The decrease is much greater than that of BCM-5, and quartz shows the same change. This is sample no. BCM-13-2 and Sample No. In BCM-14-1, sample No. It indicates that the hydration reaction was more active than that of BCM-5. Sample No. from BCM-5 BCM-13-2 and Sample No. The mortar compressive strength of BCM-14-1 is further developed.

Sample No. observed on SEM BCM-5 and Sample No. BCM-13-2 and Sample No. The difference from BCM-14-1 is almost as shown in FIGS. 27 and 28.

FIG. 27 is a view showing an SEM pattern of a BCM cement mortar to which a fluidizing agent is added at a magnification of 2000, and FIG. 28 is a view showing an SEM pattern of a BCM cement mortar to which a fluidizing agent is added at a magnification of 5000.

Sample No. BCM-13-2 and BCM14-1 are sample No. Mingling, or clustering, is more pronounced than the BCM-5. Agglomeration of particles into each other can lead to a dense structure, which is effective in increasing the compressive strength. Mining phenomenon is the pattern found in high-strength concrete cement mortar. Sample BCM-13-2 and sample no. It is unusual to see the same phenomenon in BCM-14-1 cement mortar.

29 and 30, the sample No. BCM-14-1 and Sample No. The PSD of BCM-13-2 is shown. Sample No. PSD of BCM-14-1 was sample No. Although not significantly different from BCM-5, Sample No. BCM-13-2 is sample No. More pores (100nm-10,000nm) are distributed than BCM-5. Sample No. BCM-13-2 is sample No. While there were more 100-1000 nm pores than BCM-14-1, the sample No. The BCM-14-1 is more interspersed with 500-10,000 nm pores, so in fact Sample No. BCM-14-1 is the sample No. It is not more compact than BCM-13-2. In addition, even in the size of 70-80 nm, sample No. BCM-13-2 is the sample No. In view of the overall distribution of BCM-14-1, Sample No. BCM-13-2 is the sample No. It is considered to be more compact than BCM-14-1. Sample No. also in terms of compressive strength. BCM-8 is the sample No. The reason for this is higher than that of the BCM-9.

Hereinafter, an embodiment of the high performance concrete according to the present invention using the bottom ash sand will be described.

In the present invention is to develop high-performance concrete using the high-performance concrete cement mortar and BAS fine aggregate using the above-described BAS fine aggregate.

Test of the BAS fine aggregate concrete according to the present invention will be described according to FIG. 31 is a test flow chart of BAS fine aggregate concrete according to the present invention.

That is, in the present invention is to replace the BAS fine aggregate with natural crushed stone aggregate for the development of high-performance concrete of about 600-800 kg / cm ² of concrete strength. BAS fine aggregates were used for the purpose of supplementing the strength by adding pozzolanic materials in anticipation that BAS fine aggregates could weaken the strength of concrete. At the same time, we investigated how the BAS concrete strength changed when the coarse aggregate size was adjusted.

In the test according to the present invention, the domestically produced crushed natural coarse aggregate was used as it is to develop high-performance concrete of 600-800 kg / cm ² , and the crushed fine aggregate was replaced with BAS fine aggregate to select the optimum compounding ratio. . Therefore, in order to manufacture such high-performance concrete, concrete is produced from the bottom ash generated at the power plant under the condition of using fine aggregates. Therefore, after determining the minimum unit cement amount, minimizing the water / cement ratio in consideration of construction property, and the dosage of the high-performance water reducing agent, etc. In addition, BAS fine aggregates provide the data for developing high-performance concrete.

In addition, in order to solve the problem of increase in the manufacturing cost of concrete, the optimum amount of unit cement to satisfy the required compressive strength is determined. An assimilation agent was used. Coarse aggregates are to be easily purchased crushed aggregates used in ready-mix concrete company, and the size of the coarse aggregates by changing the size of the impact on the concrete strength. And, the bottom ash sand produced as a by-product from the power plant was prepared to 5mm or less.

 That is, the quality of cement has a great influence on the strength expression in the production of high-performance concrete. Therefore, it is necessary to use cement in good storage condition, so that the cement necessary for mixing is purchased and tested at that time.

Next, the cement used in the present invention is manufactured by H company in Korea, and is shown in Chemical Compositions and Tables 25 and 26, respectively.

Table 25 Chemical Composition of Cement

SiO ₂ Al ₂ O ₃ Fe ₂ O ₃ CaO MgO SO ₃ lg-Loss F-CaO 21.2 6.5 3.1 60.9 3.5 2.2 1.7 1.1

Table 26 Physical Properties of Cement

Powder level (cm ² / g) Stability (%) First minute Termination (minutes) 3 days strength 7 days strength 28 days strength 3,556 0.09 292 487 220 286 373

In addition, the granular granules are advantageous for the strength expression of the crushed stone having a specific surface area, small wear rate, and angled grains for increasing adhesion between aggregate and cement paste. In high performance concrete, it is particularly preferable to use a small aggregate in order to increase the attachment area and to reduce the defect of the aggregate itself.

However, according to the existing research results, high-performance concrete having a compressive strength of about 600-800 kg / cm ² can be sufficiently manufactured even by using 25 mm aggregate. In addition, the aggregate is generally used in Korea at this time 25mm is the main species, the situation is the most produced in the present invention uses the maximum size of the coarse aggregate 25mm used for the compounding strength 600-800kg / cm ² in the present invention It was. The physical properties of the coarse aggregate used in the test formulation according to the invention are shown in Table 27.

Table 27 Physical Properties of Natural Coarse Aggregate

Maximum aggregate size Assembly rate importance Water absorption Unit weight 25 mm 6.95 2.61 1.29% 1571 kg / m ³

In addition, in the present invention, the crushed fine aggregate used as fine aggregate was used natural fine aggregate supplied to general ready mixed concrete, and the physical property comparison with bottom ash fine aggregate is shown in Table 28. As can be seen in Table 28, the bottom ash specific gravity 2.20 is very low compared to the crushed stone aggregate specific gravity 2.65.

(Table 28) Fine aggregate physical properties

division Assembly rate importance Salinity Content Water absorption Crushed stone aggregate 2.83% 2.65 0.002% 1.15% BAS Fine Aggregate 3.34% 2.20 - 3.8%

Next, the pozolan and chemical admixture used in the present invention will be described.

In moderate strength concrete, the water / cement ratio is relatively large, so the workability is not a big problem except when the transportation time is long. However, in the case of high-strength concrete with low water / cement ratio, it is inevitable to use a high fluidizing agent which is widely used in Korea in order to secure required workability. However, if a certain amount (about 2%) is used, aggregate separation may occur, and problems such as compatibility with other admixtures may occur, so it is desirable to reduce the amount used. The high performance sensitizers used so far are mainly naphthalene-based, and in recent years, various admixtures having improved performances have been developed. Therefore, in the present invention, the product of H company was used as the naphthalene system as the high performance water reducing agent and the polycarboxylic acid system as the high fluidizing agent. Table 29 shows the chemical composition and physical properties of the high performance water reducing agent and the high fluidizing agent.

Table 29: Chemical Components and Physical Properties of High-Performance Water-Reducing Agents and High Fluidizing Agents

color shape chief ingredient importance pH Solid content bitumen Liquid Naphthalene system 1.20 9.0 40 bitumen Liquid Polycarboxylic acid system 1.20 7.3 39.5

In addition, pozzolanic material (DS ₇₀₀ ), which plays a role in increasing the long-term strength of concrete, is a mixture of blast furnace slag powder and diatomaceous earth powder.

CaO: 33.5, SiO ₂ : 44.2, Al ₂ O ₃ : 14.0, MgO: 4.9, Fe ₂ O ₃ : 0.8, SO ₃ : 1,4, K ₂ O: 0.4, Na ₂ O: 0.9, LOI: 0.1 . DS ₇₀₀ was commercially available from H.

Cement mortar, which was most effective in increasing the compressive strength in the above-mentioned cement mortar test (see Table 24), was used as the sample no. BCM-6, Sample No. BCM-8. However, sample No. BCM-6 is a German import additive, sample No. The compressive strength was almost the same as that of BCM-8, and no further experiments were conducted. Therefore, sample No. BCM-8 and Sample No. Compressive strength after the addition of high performance fluidizing agent to BCM-9 shows a significant improvement in compressive strength. Among them, PCA (Poly Carbonate Acid) fluidizing agent was the most effective, followed by Powercon-100, so the above two chemical admixtures were selected in concrete.

At this time, the cement mortar with the best compressive strength was improved. And BCM-13-2 ² underwater curing 7 days compressive strength of 584kg / cm as, underwater curing 28 day compressive strength is shown here to 710kg / cm ^2, the sample as BAS cement mortar to produce an at least high-performance concrete No. BCM-13-2 was selected.

As can be seen from Table 30 and Table 31, the parameters of the mixing experiment were fixed after the residual aggregate rate was fixed to 22% in order to secure required compressive strength and workability of high-performance concrete in which natural fine aggregate was replaced with BAS fine aggregate. (C: 890 kg / m ³ ), water / cement ratio (W / C: 0.2%), natural coarse aggregate 37%, high-performance fluidizing agent and high-performance water reducing agent at the same time, the slump (slump) to 1-3mm Minimal amounts (8-9%) were mixed as appropriate. The air volume was estimated at 2.0%.

Table 30 Physical Properties of Aggregate

Maximum dimension (mm) importance Assembly rate Crushed coarse aggregate 25 2.61 6.95 BAS Fine Aggregate 5 2.22 3.34

The characteristics of this blend design were as follows.

  Bound air trapped: 2.0%

  Fine aggregate rate: 45%

Unit Quantity: 188 l / m ³

  Design Strength: 15% of construction site's coefficient of variation

800 × 1.123 = 898 kg / cm 2 by the curve II

  W / C: 20%

Table 31 Modified Design of Formulations

Edit item Reference condition Formulation condition s / a = 45% W = 188 l / m ³ F.M. of sand 2.75 3.34 2.95 W / C 0.55 0.20 -7 slump 7.5 One -5.2 Sum Modified design value 41.0% 178 l / m ³

Next, the change in the strength of concrete according to the amount of PCA added will be explained.

The change in compressive strength of high-performance concrete with BAS fine aggregate and natural crushed fine aggregate was changed by 0.25%, 0.50%, and 0.75% of cement addition amount. At this time, 0.5% amount of cement was mixed in all the formulations with CaCl ₂ as a reaction accelerator, and DS ₇₀₀ was once excluded (see Table 32).

(Table 32) Changes in concrete strength with changes in PCA content

(Unit kg / m ³ )

Kind Sample No.Material CTL Concrete BAS Concrete One 2 3 4 5 6 cement 890 890 890 890 890 890 DS ₇₀₀ - - - - - - Crushed coarse aggregate (-25mm) 799 799 799 799 799 799 Crushed stone aggregate (-5mm) 469 469 469 - - - BAS Fine Aggregate (-5mm) - - - 469 469 469 water 178 178 178 178 178 178 PCA (%) 0.25 0.50 0.75 0.25 0.50 0.75 CaCl ₂ (%) 0.5 0.5 0.5 0.5 0.5 0.5 Slump (mm) 1-3 1-3 1-3 1-3 1-3 1-3 Air (%) 2.0 2.0 2.0 2.0 2.0 2.0

CTL Concrete: Control Concrete

     BAS Concrete: Bottom Ash Sand Concrete

DS ₇₀₀ : Pozzolane Blend

Next, the changes in the strength of BAS concrete with the addition of pozzolanic (DS ₇₀₀ ) will be explained.

Based on the test results of the high fluidizing agent, it is considered that 0.5% is appropriate for the amount of concrete for high-performance concrete using BAS fine aggregates, so that 0.5% of the high fluidizing agent and the reaction promoter are fixed by 0.5% and cement amount of DS ₇₀₀ (pozzolanic material) is cemented. After compressing 0%, 5.0%, 10.0% and 20.0%, compressive strength was examined (see Table 33).

Table 33. BAS Concrete Compressive Strength According to Pozzolan (DS ₇₀₀ ) Change

(Unit kg / m ³ )

Kind Sample No.Material BAS Concrete 5 7 8 9 cement 890 845 801 712 DS / 700 0 45 89 178 Crushed coarse aggregate (-25mm) 799 799 799 799 BAS Fine Aggregate (-5mm) 469 469 469 469 water 178 178 178 178 PCA (%) 0.5 0.5 0.5 0.5 CaCl ₂ (%) 0.5 0.5 0.5 0.5 Slump (mm) 1-3 1-3 1-3 1-3 Air (%) 2.0 2.0 2.0 2.0

Next, the change in compressive strength of BAS concrete by aggregate size will be explained.

Change in strength by adding DS ₇₀₀ pozzolan with 10% cement and BAS fine aggregate, and adding high-flowing agent (0.5%) and reaction accelerator (0.5%), respectively, and changing crushed aggregate dimensions to 25mm, 19mm, 13mm, and 10mm Was investigated (see Table 34).

(Table 34) BAS Concrete compressive strength change by aggregate size

(Unit kg / m ³ )

Kind Sample No.Material BAS Concrete 8 10 11 12 cement 801 801 801 801 DS ₇₀₀ 89 89 89 89 Crushed aggregate (-25mm) 799 - - - Crushed aggregate (-19mm) - 799 - - Crushed aggregate (-13mm) - - 799 - Crushed aggregate (-10mm) - - - 799 BAS Fine Aggregate (-5mm) 469 469 469 469 water 178 178 178 178 PCA (%) 0.5 0.5 0.5 0.5 CaCl ₂ (%) 0.5 0.5 0.5 0.5 Slump (mm) 1-3 1-3 1-3 1-3 Air (%) 2 2 2 2

Next, the change of compressive strength according to the design strength (400kg / cm ² , 600kg / cm ² , 800kg / cm ² ) of BAS concrete is explained.

Based on the combination that changes the coarse aggregate dimensions, the natural coarse aggregate (-25mm) is used as it is, the high-flowing agent and the reaction promoter are fixed by 0.5%, respectively, and the design strength is 400, 600, 800 kg / m, respectively. After changing to ² , the compressive strength was examined (see Table 35).

(Table 35) BAS concrete design strength change

(Unit kg / m ³ )

Kind Sample No.Material BAS Concrete Design Strength 400kg / cm ² 600kg / cm ² 800 kg / cm ² 13 14 15 16 17 18 cement 609 548 826 843 890 801 DS / 700 - 61 - 83 - 89 Crushed coarse aggregate (-25mm) 864 864 831 831 799 799 BAS Fine Aggregate (-5mm) 594 594 526 526 469 469 water 185 185 185 185 185 185 PCA (%) C × 0.5 C × 0.5 C × 0.5 C × 0.5 C × 0.5 C × 0.5 Powercon - - - - - - CaCl ₂ (%) C × 0.5 C × 0.5 C × 0.5 C × 0.5 C × 0.5 C × 0.5 Slump (mm) 1-3 1-3 1-3 1-3 1-3 1-3 air(%) 2.0 2.0 2.0 2.0 2.0 2.0

Next, the application of PCA and high performance water reducing agent Powercon to BAS concrete will be described.

Based on the design strength of 800 kg / m ² , the strength of concrete produced from crushed aggregate and BAS aggregate was investigated. At this time, 10% DS ₇₀₀ pozzolanic acid was added to the BAS fine aggregate concrete. At the same time, the performance of the high-flowing agent and the high performance water reducing agent was compared with them (see Table 36).

(Table 36) Change in compressive strength with addition of high fluidizing agent and water reducing agent

(Unit kg / m ³ )

Kind Sample No.Material CTL Concrete BAS Concrete 19 20 21 22 cement 890 890 801 801 DS / 700 - - 89 89 Crushed coarse aggregate (-25mm) 799 799 799 799 Crushed stone aggregate (-5mm) 469 469 - - BAS Fine Aggregate (-5mm) - - 469 469 water 185 185 185 185 PCA (%) C × 0.5 - C × 0.5 - Powercon (%) - C × 0.5 - C × 0.5 CaCl ₂ (%) C × 0.5 C × 0.5 C × 0.5 C × 0.5 Slump (mm) 1-3 1-3 1-3 1-3 air(%) 2.0 2.0 2.0 2.0

Next, the fabrication and testing of the specimen according to the present invention will be described.

According to the high-performance concrete mix design standard, after adjusting the pozzolanic and chemical admixtures as natural ash coarse aggregate (-25mm) and BAS fine aggregate (-5mm) instead of natural fine aggregate, concrete specimens (Ψ100mm × L 200mm) were manufactured. 28 days compressive strength was measured. As described above, the air amount was estimated at 2.0% and the slump was maintained in the range of 1-3 cm.

As a result of aggregate quality, coarse aggregates are shown in Table 37, Coarse aggregate samples were compared with KS specification.

(Table 37) Quality result of coarse aggregate (-25mm)

Test Items Unit (pass weight percentage,%) KS Specification Standard (Crushed Stone 57 Aggregate) result Crushed stone aggregate  mouth  Degree 40 mm % 100 92.5 25 mm % 95-100 97.4 20 mm % - 82.4 13 mm % 25-60 62.8 10 mm % - 13.1 No.4 % 0-10 0 No.8 % 0-5 0 PAN % - - importance g / cc 2.5 or more 2.63 Water absorption % Less than 3% 0.73 # 200 sieve % 1.0% or less - Unit weight kg / m ³ - 1502 Assembly rate % - 6.95

Crushed aggregates have a specific gravity of 2.63, which satisfies KS 2.5. The water absorption rate is (0.73%), which satisfies KS specification 3.0% or less and is very good. The unit weight of crushed aggregate is 1502 kg / m ^{3, which} is included in the KS specification and the assembly rate is 6.95, which satisfies the specification. Fig. 32 shows the particle size distribution curves by the color difference. As can be seen in Figure 32, generally the crushed aggregates all meet the specification specification KS crushed stone 57 aggregate specifications.

In addition, Table 38 summarizes the BAS fine aggregates used as concrete fine aggregates in comparison with natural crushed sand quality and KS standards. 33 shows the particle size distribution of the crushed sand compared with the KS standard. As can be seen from Table 38 and FIG. 33, the quality of the crushed sand is a good result that satisfies the KS standard. However, the proportion of BAS fine aggregates is 2.22, which falls short of the KS specification.

Table 38 Natural Fine Aggregate (Crushed Sand) Test

  Test Items Unit (pass percentage by weight) KS specification standard (concrete aggregate for concrete) result Natural crushed stone aggregate BAS Fine Aggregate Granularity 10 mm 100 99.8 100 No.4 95-100 95.4 95 No.8 80-100 80.6 86 No.16 50-85 58.5 69 No.30 25-60 39.6 49 No.50 10-30 21.1 30 No.100 2-10 8.3 12 PAN - - importance - 2.5-2.65 2.631 2.22 Water absorption % 1-6 1.594 3.9 stability % - 3.2 -

BAS fine aggregate absorption rate was 3.0%, which was higher than that of crushed stone, but it can be seen that the quality satisfies KS standard of general aggregate.

Table 39 shows the particle size distribution of BAS fine aggregates compared with cinders. In Table 39, it can be seen that the particle sizes of the crushed stone and the BAS fine aggregate are all good particle sizes satisfying the standard particle size range.

(Table 39) Quality comparison of BAS fine aggregates

Test Items BAS Sand Crushedstone KSstandard (general) KS standard (recycled aggregate) Type 1 Type 2 Type 3 Specificgravity 2.22 2.63 2.5 2.2 2.2 2.2 Absorption (%) 3.90 0.73 3%> 3%> 5%> 7%> Passing of 0.08mm (%) - - One%> 1.5%> 1.5%> Unit volumeweight (kg / m ³ ) - 1502 - - - - F.M. 3.34 6.95 - - - -

In addition, mechanical vibration compaction and hand compaction were used simultaneously for the production of concrete specimens. The theoretical air volume was estimated at 2.0%. The specimens were cured under water at room temperature and the compressive strength was measured after curing in water for 7 days and 28 days. However, the specimens were cut with a cutting machine for horizontal adjustment to the specimen surface when measuring the high-strength concrete compressive strength. In addition, in the test of the present invention, since the cutting machine did not perfectly level the surface of the specimen and eccentricity was easily generated, the maximum compressive strength was used among the three specimens. The reason for quoting the maximum value is that when the eccentricity does not occur, the probability of the maximum value can be shown.

Next, in this invention, the effect of a high fluidizing agent (PCA) is demonstrated.

The change in compressive strength when the amount of high fluidizing agent added to concrete is shown in FIGS. 34 and 40. Natural coarse aggregates and natural fine aggregates were used for general and high-strength concrete (adjusted specimens), and the test concrete was replaced with BAS fine aggregates instead of natural fine aggregates. In general high-strength concrete, as the amount of PCA gradually increased, the 7-day and 28-day curing compressive strengths also increased. Based on 28 days curing strength in water, 575 kg / cm ² was added at 0.25%, 737 kg / cm ² at 0.5%, and 883 kg / cm ² at 0.75%. . However, BAS fine aggregate concrete showed high strength as 694 kg / cm ² when 0.25% was added, based on 28 days curing compressive strength, but little change when 0.5% was added (690 kg / cm ² ). In addition, the compressive strength was decreased (630 kg / cm ² ) when 0.75% was added. Even if the amount of PCA was added to the fine aggregate concrete, the compressive strength did not change significantly depending on the amount added. However, assuming that the BAS fine aggregate concrete had a lot of eccentricity, and the BAS fine aggregate was not affected by PCA, it was found that 0.5% of cement was the maximum for using BAS fine aggregate in concrete. Therefore, specimen No. 5 added with 0.5% of PCA and 0.5% of CaCl ₂ was also selected for the production of BAS concrete.

(Table 40) Changes in concrete strength with changes in PCA content

(Unit kg / m ³ )

              Kind Sample No.Material CTL Concrete BAS Concrete One 2 3 4 5 6 cement 890 890 890 890 890 890 DS ₇₀₀ - - - - - - Crushed coarse aggregate (-25mm) 799 799 799 799 799 799 Crushed stone aggregate (-5mm) 469 469 469 - - - BAS Fine Aggregate (-5mm) - - - 469 469 469 water 178 178 178 178 178 178 PCA (%) C × 0.25 C × 0.50 C × 0.75 C × 0.25 C × -0.50 C × 0.75 CaCl ₂ (%) C × 0.5 C × 0.5 C × 0.5 C × 0.5 C × 0.5 C × 0.5 Slump (mm) 1-3 1-3 1-3 1-3 1-3 1-3 Air (%) 2.0 2.0 2.0 2.0 2.0 2.0 Compressive strength (kg / cm ² ) 7 days 460 600 721 419 599 525 28 days 575 737 883 694 690 630

      CTL Concrete: Control Concrete

    BAS Concrete: Bottom Ash Sand Concrete

DS ₇₀₀ : Pozzolane Blend

Next, the effect by the addition amount of pozzolane (DS ₇₀₀ ) is demonstrated.

As can be seen from Table 41 and FIG. 35, 800 kg / cm ² design strength was fixed to 0.5% PCA and 0.5% CaCl ₂ in BAS concrete, and 0%, 5%, 10%, 20 for pozzolanic (DS ₇₀₀ ). % Was replaced with cement and the compressive strength was investigated. In general, when the 28-day curing strength is compared with the 7-day curing strength, the increase in the compressive strength with the longer curing period is consistent with the phenomenon that the strength increases with the general curing period. When the DS ₇₀₀ was added 20%, the 7-day compressive strength was 486 kg / cm ² and the 28-day compressive strength was 719 kg / cm ^2, which was increased by 48% from 7 to 28 days. Compared with this, 17% was reduced. In addition, when the DS ₇₀₀ was added 10%, the curing 7-day compressive strength was 690 kg / cm ² and the curing 28-day compressive strength was 817 kg / cm ² , indicating an increase of about 18% from 7 to 28 days. The addition of 5% of DS ₇₀₀ approximates the design strength. When DS ₇₀₀ was not added, the compressive strength at 7 days was 599 kg / cm ² and at 690 kg / cm ^{2 on} 28 days, it was less than the design strength. The compressive strength increase rate during the 7 to 28 days was 15-48%, but it was hard to believe the curing strength because it did not reach the design strength and did not comply with the strength increase rate after general concrete curing.

In addition, when 10% of DS ₇₀₀ was added and 0% of DS ₇₀₀ was added, the increase in compressive strength of about 15-18% after 7 to 28 days of curing was almost the same as that of general concrete. Invisible In view of this background, No.8 (added 10% DS ₇₀₀ ) concrete is not considered to be a relatively reliable strength change, but compared to the design strength of 800 kg / cm ² , the 28-day curing strength was 817 kg / cm ^2. .8 shows the feasibility of producing high performance concrete.

(Table 41) pozzolan (DS ₇₀₀₎ BAS concrete compressive strength according to the added amount change

(Unit kg / m ³ )

Kind Sample No.Material BAS Concrete 5 7 8 9 cement 890 845 801 712 DS / 700 0 45 89 178 Crushed coarse aggregate (-25mm) 799 799 799 799 BAS Fine Aggregate (-5mm) 469 469 469 469 water 178 178 178 178 PCA (%) C × 0.5 C × 0.5 C × 0.5 C × 0.5 CaCl ₂ (%) C × 0.5 C × 0.5 C × 0.5 C × 0.5 Slump (mm) 1-3 1-3 1-3 1-3 Air (%) 2.0 2.0 2.0 2.0 Compressive strength (kg / cm ² ) 7 days 599 428 690 486 28 days 690 634 817 719

Next, the effect of the coarse aggregate size will be described.

36 and Table 42 show the change in compressive strength in BAS concrete when the standard coarse aggregate (-25mm) is changed to -19mm, -13mm, and -10mm sizes. In general, as the coarse aggregate size was replaced with smaller aggregates, the 7-day and 28-day compressive strengths of curing did not improve significantly. Especially, when comparing 28 days of compressive strength only, sample No.9 concrete replaced with -19mm aggregate was 714 kg / cm ² , which was lower than standard coarse aggregate (-25mm), and replaced with -13mm aggregate. 618 kg / cm ² , which was significantly lower than the standard coarse aggregate. In addition, when replaced with -10mm, it was still 801 kg / cm ² compared to the standard aggregate. The smaller the coarse aggregate size, the lower the compressive strength is considered to be due to the lack of proper compaction due to the increase of cement paste space on the concrete compaction or the eccentricity on the specimen. Therefore, it can be seen that even BAS concrete should fall within the coarse aggregate particle size range suggested in general concrete.

(Table 42) BAS concrete compressive strength change by aggregate size

(Unit kg / m ³ )

                 Kind Sample No.Material BAS Concrete 8 10 11 12 cement 801 801 801 801 DS / 700 89 89 89 89 Crushed aggregate (-25mm) 799 - - - Crushed aggregate (-19mm) - 799 - - Crushed aggregate (-13mm) - - 799 - Crushed aggregate (-10mm) - - - 799 BAS Fine Aggregate (-5mm) 469 469 469 469 water 178 178 178 178 PCA (%) C × 0.5 C × 0.5 C × 0.5 C × 0.5 CaCl ₂ (%) C × 0.5 C × 0.5 C × 0.5 C × 0.5 Slump (mm) 1-3 1-3 1-3 1-3 Air (%) 2 2 2 2 Compressive strength (kg / cm ² ) 7 days 690 631 577 719 28 days 817 744 618 801

Next, the design strength effect of BAS concrete will be explained.

The effect of BAS fine aggregates on compressive strength when the BAS concrete design strength is changed to 400 kg / cm ² , 600 kg / cm ² , 800 kg / cm ² using coarse aggregate (-25mm) The results are shown in Figure 37 and Table 43. First, at 400 kg / cm ² of design strength, the actual measured compressive strength was 58% and 71% higher than the design strength for 28 days of curing, respectively. At the same time, pozzolanic (DS ₇₀₀ ) was higher than the design strength by 35% and 73%, respectively, during the same curing period. In addition, BAS concrete without pozzolanic (DS ₇₀₀ ) at 600 kg / cm ² design strength increased by 14% in 7 days curing and 22% in 28 days curing than design strength. At the same time, when pozzolanic (DS ₇₀₀ ) was mixed, the design strength was higher by 11% and 30%, respectively, during the same curing period. The design strength of 800 kg / cm ² pozzolan (DS ₇₀₀₎ for measuring the actual strength of the concrete mix is BAS curing 7 days was not reached the design strength (23% decrease), it cured 28 days in some reduction in the design strength ( -2% decrease). Even when pozzolanic (DS ₇₀₀ ) was mixed, the actual measured strength decreased 21% and 7%, respectively, from the design strength during the same curing period (see Table 44 and Figure 38).

(Table 43) BAS concrete design strength change

(Unit kg / m ³ )

Kind Sample No.Material BAS Concrete 400kg / cm ² 600kg / cm ² 800 kg / cm ² 13 14 15 16 17 18 cement 609 548 826 743 890 801 DS / 700 - 61 - 83 - 89 Crushed coarse aggregate (-25mm) 864 864 831 831 799 799 BAS Fine Aggregate (-5mm) 594 594 526 526 469 469 water 185 185 185 185 185 185 PCA (%) C × 0.5 C × 0.5 C × 0.5 C × 0.5 C × 0.5 C × 0.5 CaCl ₂ (%) C × 0.5 C × 0.5 C × 0.5 C × 0.5 C × 0.5 C × 0.5 Slump (mm) 1-3 1-3 1-3 1-3 1-3 1-3 Air (%) 2.0 2.0 2.0 2.0 2.0 2.0 Compressive strength (kg / cm ² ) 7 days 631 541 681 665 648 663 28 days 684 692 734 775 784 750

(Table 44) Comparison of design strength and actual measured value

Design strength DS ₇₀₀ (%) Curing days Actual measurement strength increase / decrease rate according to design strength (%) increase decrease 400 0 7 58 - 28 71 - 10 7 35 - 78 73 - 600 0 7 14 - 28 22 - 10 7 11 - 28 30 - 800 0 7 - 23 28 - 2 10 7 - 21 28 - 7

As shown in Table 44, the higher the design strength, i.e. the higher the cement content, the lower the compressive strength and the lower the design strength (e.g. 800 kg / cm ² ) without effect on curing. Since the volume occupied by the aggregate is larger than the volume occupied by the aggregate or because it contains unnecessary cement, it may be an important factor to limit the compaction. In addition, the mixing effect of pozzolanic (DS ₇₀₀ ) also does not seem to have a significant effect on the high compressive strength. Another reason is that because it is designed with high-strength concrete (eg 800kg / cm ² ), more eccentricity is generated when cutting the specimen surface, so that the proper compressive strength could not be measured.

This assumption can be demonstrated at 400 kg / cm ² with low design strength. That is, after 7 days of curing, the actual measured strength increased by 58% from the design strength, and after 28 days of curing, it increased by 71%. It can be assumed that the relationship between the cement content and the aggregate content has an effect on compaction, and the low design strength can support the hypothesis that specimen surface cutting does not occur. It is also supported by the fact that pozzolanic (DS ₇₀₀ ) mixing at 400 kg / cm ² influences the strength increase. Cement supports this assumption even at relatively high design strengths of 600 kg / cm ² .

That is, after 7 days and 28 days of curing for pozzolanic (DS ₇₀₀ ), the actual measured strength increased more than the design strength, but was significantly lower than 400 kg / cm ² and significantly higher than 800 kg / cm ^2. This is convincing. In conclusion, the strength of high-performance BAS concrete in the form of 800 kg / cm ² design strength is less than 800 kg / cm ² design strength because the unbalanced volume between cement and aggregate and high-strength concrete make cutting the specimen surface more difficult. It is considered that the cause is the eccentricity on the surface.

Next, the effects of the high fluidizing agent and the high performance water reducing agent on BAS concrete will be explained.

As shown in Table 45 and FIG. 39, in the case of high-performance general concrete made only of crushed natural aggregates, the change in compressive strength due to the addition of a high fluidizing agent and a high-performance water reducing agent did not appear significantly on 7 days or 28 days of curing. On the basis of 7-day curing, the lowest compressive strength (384 kg / cm ² ) was found when the high-flowing agent was added, and the compressive strength (737 kg / cm ² ) increased by almost 100% in 28-day curing. At the same time, even in the same general concrete, high performance water reducing agents were not significantly improved. It is contemplated that illustrates the problematic (yangnae cement aggregate amount of non-related) to the eccentric and the concrete mix design strength 800 kg / cm ² in strength concrete claimed. BAS concrete mixed with pozzolanic DS ₇₀₀ did not show a significant effect of the addition of a high fluidizing agent. The 7-day curing strength of 631 kg / cm ² is a routine result, but after 28-day curing, it does not reach the design strength (800 kg / cm ² ). The effect of the addition of high performance water reducing agents on BAS concrete mixed with pozzolanic DS ₇₀₀ was also not significant. That is, the 7-day curing compressive strength (490 kg / cm ² ) was significantly reduced compared to the high fluidizing agent, but the 28-day curing compressive strength (748kg / cm ² ) was increased by almost 90% compared to the 7-day compressive strength. Almost the same effect as the assimilation. Therefore, in the BAS concrete mixed with pozzolanic (DS ₇₀₀ ), a high fluidizing agent or a high performance water reducing agent did not find any significant difference in compressive strength improvement.

(Table 45) Compressive strength change according to the addition of high fluidizing agent and water reducing agent

(Unit kg / m ³ )

Kind Sample No.Material CTL Concrete BAS Concrete 19 20 21 22 cement 899 899 801 801 DS / 700 - - 89 89 Crushed coarse aggregate (-25mm) 799 799 799 799 Crushed stone aggregate (-5mm) 469 469 - - BAS Fine Aggregate (-5mm) - - 469 469 water 185 185 185 185 PCA (%) C × 0.5 - C × 0.5 - Powercon (%) - C × 0.5 - C × 0.5 CaCl ₂ (%) C × 0.5 C × 0.5 C × 0.5 C × 0.5 Slump (mm) 1-3 1-3 1-3 1-3 Air (%) 2.0 2.0 2.0 2.0 Compressive strength (kg / cm ² ) 7 days 384 546 631 490 28 days 737 647 744 748

28 days water curing the increase, as much as 800 kg / cm ² design strength cement × 0.25% of superplasticizer (PCA) in normal strength concrete and BAS high-performance concrete, cement × 0.5%, cement × 0.75% as described above, Comparing the compressive strength only, the general high strength concrete showed 575 kg / cm ² , 747 kg / cm ² , and 883 kg / cm ² , which increased with increasing PCA. At the same design strength, BAS concrete showed 694 kg / cm ² (0.25%), 690 kg / cm ² (0.5%) and 630 kg / cm ² (0.75%). It was far less than the design strength.

800 kg / cm ² Design strength When BAS concrete was added 0.5% of PCA and CaCl ₂ to cement, respectively, and DS ₇₀₀ pozzolan was replaced with cement by 0%, 5%, 10%, and 20%, 28 days of water curing compressive strength was In general, they did not reach the design strength (800 kg / cm ² ). However, when the DS ₇₀₀ was replaced by 10%, the compressive strength exceeded the design strength as 817 kg / cm ² and the DS ₇₀₀ pozzolanic effect was also very high. DS ₇₀₀ 0% when added exhibited a _{^{670 kg / cm 2, DS 700}} 5% , the addition of _{^{634kg / cm 2, DS 700 20}} % is 719 kg / cm ² during the addition.

Design strength 800 kg / cm ² BAS concrete replaced -25mm of standard natural coarse aggregate with -19mm, -13mm, and -10mm.The resultant aggregates showed compressive strength when standard coarse aggregate was based on 28 days of underwater curing. Lower than (817 kg / cm ² ). -19mm coarse aggregates are 744 kg / cm ² , -13mm coarse aggregates are 618 kg / cm ² , and -10mm coarse aggregates are 801 kg / cm ^{2, which} is generally less than the design strength (800 kg / cm ² ).

When the design strength of the BAS concrete is changed to 400 kg / cm ² , 600 kg / cm ² , 800 kg / cm ² (with or without the addition of 10% pozzolanic DS ₇₀₀ ) In all cases the compressive strength was reduced. The design strength of 800 kg / cm ² BAS concrete, which contains the largest amount of cement used in concrete, did not reach the design strength (800 kg / cm ² ) in both 7 and 28 days of curing water. That is, the 7-day compressive strength (648-663 kg / cm ² ) was reduced by 21-23%, the compressive strength (750-784 kg / cm ² ) was reduced by 2-7% on 28 days. However, the design strength of 600 kg / cm ² illustrates the BAS underwater curing concrete 7 and 28 day compressive strength of each of 665-681kg / cm ² and 734-775 kg / cm ² than the design strength (600kg / cm ²⁾ 11-14 % (Cure 7 days) and 22-30% (28 days). Design strength 400 kg / cm ² BAS concrete underwater curing 7 and 28 days compressive strength was higher than design strength (400kg / cm ² ). The 7-day curing showed 541-631 kg / cm ² and the 28-day curing showed 684-692 kg / cm ² , showing 35-58% increase (7 days) and 71-73% increase (28 days), respectively.

To obtain the compressive strength (600-800kg / cm ² ) of high-performance concrete, BAS concrete has a design strength of 400-600 kg / cm ² , PCA (0.5% cement) + CaCl ₂ (0.5% cement) and pozzolane DS ₇₀₀ Is replaced by 10% cement. The air volume should be maintained at 2.0% and the slump of 1-3cm.

As mentioned above, although the invention made by this inventor was demonstrated concretely according to the said Example, this invention is not limited to the said Example and can be variously changed in the range which does not deviate from the summary.

As described above, according to the composition of the high-performance concrete using the bottom ash of the present invention and a method for producing the same, it has been discarded so far as a substitute for natural aggregates that are gradually depleted or artificial aggregates that cause environmental pollution or natural damage. Bottom ash, a type of coal-fired coal-fired power plant, can be used as a substitute to provide high-performance concrete with similar or higher compressive strength than existing products.

In addition, according to the composition of the high-performance concrete using the bottom ash of the present invention and a method of manufacturing the same, by using the bottom ash, which is an industrial waste discharged from the thermal power plant as a replacement for the existing concrete composition, as well as solving the problems caused by aggregate depletion The effect of contributing to the preservation of the environment is also obtained by utilizing wastes being disposed of as landfills as construction resources.

1 is a progress of an experiment for carrying out the composition of high-strength cement mortar using a bottom ash and a method for producing the same;

Figure 2 is a graph of the change in W / C (%) of CTL and BCM-1 at flow 142 ± 10,

3 is a graph showing changes in compressive strength of CTL and BCM-1 when flow 142 ± 10,

4 is a graph showing the change in curing strength versus compressive strength of CTL and BCM-1,

5 is a graph of the change in W / C (%) according to the BAS substitution rate when flow 142 ± 10,

6 is a graph showing changes in compressive strength when replacing ordinary yarns with BAS,

7 is a graph showing the change in compressive strength of BCM vs. underwater curing days,

8 is a graph of the change in W / C (%) with the BCM cement mortar to which the admixture is added,

9 is a graph showing changes in compressive strength of BCM cement mortar to which admixtures are added;

10 is a graph of change in compressive strength according to the curing days of the BCM cement mortar to which the admixture is added,

11 is a graph of the W / C (%) change when the glidant is added to the BCM cement mortar,

12 is a graph of change in compressive strength when fluidizing agent is added to BCM cement mortar,

13 is a graph of change in compressive strength when a fluidizing agent is added to BCM-12,

14 is a graph of change in compressive strength when a fluidizing agent is added to BCM-13,

15 is a graph of change in compressive strength when a fluidizing agent is added to BCM-14,

16 is a view showing an XRD pattern of ordinary yarn and BAS cement mortar,

17 is an SEM observation diagram of a general yarn and a BAS cement mortar at a magnification of 2000;

18 is an SEM observation diagram of a general yarn and BAS cement mortar at a magnification of 5000;

19 is a diagram showing the distribution of PSD of ordinary yarns and BAS cement mortar,

20 is a diagram showing the cumulative distribution of PSD of general sand and BAS cement mortar,

21 is a view showing an XRD pattern when the admixture is added to BCM cement mortar,

FIG. 22 is an SEM observation diagram in which a admixture is added to BCM cement mortar at a magnification of 2000.

FIG. 23 is an SEM observation diagram in which a admixture is added to a BCM cement mortar at a magnification of 5000;

24 is a view showing the distribution of PSD added to the admixture to the BCM cement mortar,

25 is a view showing the cumulative distribution of PSD added to the admixture to the BCM cement mortar,

FIG. 26 is a diagram showing an XRD pattern of BCM cement mortar to which a glidant is added;

FIG. 27 is an SEM observation diagram of BCM cement mortar to which a glidant is added at a magnification of 2000; FIG.

FIG. 28 is an SEM observation diagram of BCM cement mortar to which a glidant is added at a magnification of 5000;

29 is a view showing a PSD distribution of a BCM cement mortar to which a glidant is added,

30 is a view showing the cumulative distribution of PSD of the BCM cement mortar to which the fluidizing agent is added,

31 is a BAS fine aggregate concrete test plan flow chart according to an embodiment of the present invention,

32 is a view showing the distribution of crushed stone aggregate aggregates according to an embodiment of the present invention,

33 is a view showing a particle size distribution curve of BAS fine aggregate according to an embodiment of the present invention,

34 is a view showing changes in PCA addition amount versus compressive strength according to an embodiment of the present invention;

35 is a view showing the change in strength according to the addition amount of DS ₇₀₀ pozzolanic to BAS concrete according to an embodiment of the present invention,

36 is a view showing a change in compressive strength according to the aggregate size according to an embodiment of the present invention,

37 is a view showing the amount of BAS concrete design strength added according to an embodiment of the present invention,

38 shows a comparison between design intensity and actual measured value increase and decrease according to an embodiment of the present invention;

FIG. 39 is a view showing changes in CTL and BAS compressive strengths according to the addition of a high fluidizing agent (PCA) and a reducing agent (Powercon) according to an embodiment of the present invention (0.5%).

Claims (7)

In the composition of the high-performance concrete which mixes water, cement, aggregate, and general sand, The aggregate is a coarse aggregate of natural stone, the size of the coarse aggregate of natural stone is 10 to 25 mm, Bottom ash sand, which is a waste generated from a thermal power plant, is used as a substitute for the general sand, and the size of the bottom ash sand is 5 mm or less, As a constituent of the concrete composition, the bottom ash sand contains 20 to 26% of the total required composition components per m 3, and the natural crushed coarse aggregate contains 34 to 46% of the total required composition components per m 3, Admixtures and glidants are added to the composition, The concrete composition is a composition of high performance concrete using a bottom ash, characterized in that applied to the design strength of the concrete 400 to 800kg / cm ² . The method of claim 1, The admixture is a pozzolanic admixture, and the composition of the high-performance concrete using the bottom ash, characterized in that about 10% is added to the amount of cement. The method of claim 2, The fluidizing agent is PCA (Poly Carbonate Acid), and the composition of the high-performance concrete using a bottom ash, characterized in that added to the amount of 0.25 to 0.75%. In the manufacturing method of the composition of the high performance concrete which mixes and uses water, cement, aggregate, and general sand, Preparing a natural stone coarse aggregate of 10 to 25 mm as the aggregate, A process of collecting and preparing bottom ash having a particle diameter of 5 mm or less using a sorting machine among bottom ashes generated in a thermal power plant, 20 to 26% of bottom ash sand of the total required composition components per m 3 of the high performance concrete, 34 to 46% of natural crushed coarse aggregate and admixture and fluidizing agent of the total required composition components per m 3 of the high performance concrete Method for producing a composition of high performance concrete using a bottom ash, characterized in that it comprises a step of mixing. The method of claim 4, wherein The admixture is a pozzolanic admixture, and is about 10% added to the amount of cement. The method of claim 5, The fluidizing agent is PCA, the method of producing a composition of high-performance concrete using a bottom ash, characterized in that added to the amount of 0.25 to 0.75%. The method of claim 6, The concrete composition is a method for producing a composition of high performance concrete using a bottom ash, characterized in that applied to the design strength of the concrete 400 to 800kg / cm ² .