KR102510283B1 - Perimeter supporting material for constructing phc pile - Google Patents

Abstract

The present invention relates to a main surface fixing material for high-flowability PHC pile construction using a large amount of circulating resources, and more particularly, volume stability while securing fluidity and initial strength by using a large amount of desulfurization process by-products from steelworks and power plants as a stimulant for blast furnace slag fine powder It relates to a main surface fixing material composition for this excellent PHC pile construction.
The main surface fixing material for high fluidity PHC pile construction using a large amount of circulating resources according to the present invention is based on 100 parts by weight of type 1 cement, 100 to 2,000 parts by weight of blast furnace slag fine powder, 50 to 2,000 parts by weight of sodium bicarbonate reaction by-product in the desulfurization process of steel mills, , 10 to 500 parts by weight of slaked lime reaction by-products in the steelworks desulfurization process, and 50 to 5,000 parts by weight of bottom ash discharged from the lower part of the circulating fluidized bed boiler.

Description

Main surface fixing material for high fluidity PHC pile construction using a large amount of circulating resources {PERIMETER SUPPORTING MATERIAL FOR CONSTRUCTING PHC PILE}

The present invention relates to a main surface fixing material for high-flowability PHC pile construction using a large amount of circulating resources, and more particularly, volume stability while securing fluidity and initial strength by using a large amount of desulfurization process by-products from steelworks and power plants as a stimulant for blast furnace slag fine powder It relates to a main surface fixing material composition for this excellent PHC pile construction.

Recently, pile construction using the embedded pile method is increasing according to the trend of strengthening noise and vibration regulations during pile foundation construction at construction sites.

Embedded pile construction is a method of digging a hole in the ground using an auger and planting a ready-made PHC pile or tip-extended pile. It is manufactured by mixing water with powder of first-class cement or first-class cement with bentonite added to the space between the ground and the pile. It is performed as a method of reinforcing the frictional force and bearing capacity of the pile by filling the fixed solution.

The basic role of the fixing material between the drilled hole and the pile is to play the function of the fixing material for the independence of the pile and the frictional force of the pile in the initial stage of loading.

However, since Type 1 cement is manufactured by mining limestone, which is the main raw material, and calcining it at a high temperature of 1,450 ° C, a large amount of CO ₂ gas, which is the main cause of greenhouse gases, is generated during the decarboxylation process of limestone, which causes global warming.

In addition, since cement is strong enough to reach a pH of 13 or more, it is not preferable when used in soil.

In addition, bentonite is a mineral that does not exist as a natural resource in Korea, and is an expensive material that is entirely dependent on imports. When it comes into contact with salt, its degree of swelling significantly decreases, resulting in a significant decrease in water repellency.

Recently, several technologies have been proposed to improve the performance of these existing cements. This technology uses type 1 cement as the main raw material, replaces some of it with blast furnace slag and pulverized coal boiler fly ash, and adds various expensive admixtures and admixtures (anhydrite, bentonite, calcium sulfoaluminate, calcium aluminate, etc.) am.

Therefore, the manufacturing process is very complicated, the production costs are high, and since various raw materials must be used at the same time, it is difficult to select a mixture according to variations in physical and chemical quality characteristics of raw materials.

On the other hand, in the LH specification, “the space around the pile created after driving the pile is filled with a fixing solution with a water-binding material ratio (W/B) of standard uniaxial compressive strength of 0.49 MPa or more in order to secure the horizontal resistance and surface friction of the pile. shall. If this liquid permeates into the ground, if the upper surface of the fixing liquid settles, it must be continuously replenished.” In other words, since the main fixing solution requires a very low uniaxial compressive strength, it is possible to sufficiently secure a standard uniaxial strength of 0.49 MPa or more even if the water-bonding material ratio (W/B) is 83% or more at the construction site, but high water-bonding Even if the main fixing solution of the empty mixing ratio with remediation is injected, it escapes to the ground around the pile and is not filled. Accordingly, in a site with high permeability or a lot of groundwater, a method of increasing surface friction by changing the water-binder ratio (W/B) from 83% or less to a sub-mixture such as 68% or 59% is used to secure fluidity and It is very important to prevent clogging of the tube.

In fact, if you look only at the strength side, ignoring the workability, too much cement is being put into the ground compared to the uniaxial compressive strength required for the main surface fixing solution. In addition, cement may cause environmental pollution due to strong alkali and hexavalent chromium in the ground, and volume shrinkage occurs, resulting in a decrease in frictional force on the surface of the pile.

Recently, several techniques have been proposed to improve the problems of using such conventional cement as an injection material.

For example, in Korean Patent Registration No. 10-1377552, 100 to 300 parts by weight of blast furnace slag fine powder and 20 to 100 parts by weight of petrol coke desulfurized gypsum are mixed with 100 parts by weight of coal ash having a calcium oxide content of 30 to 60%. A milk injection material technology for unused pile construction was presented.

In addition, in Korean Patent Registration No. 10-1402877, 55 to 65% by weight of blast furnace slag fine powder, 10 to 20% by weight of F-class fly ash, 10 to 20% by weight of C-class fly ash having a calcium oxide content of 20% or more, and desulfurized gypsum 2 An eco-friendly eco-filling material manufacturing technology using blast furnace slag mixed with ∼5% by weight and 10∼20% by weight of paper sludge incineration ash was proposed.

In addition, in Korean Patent Registration No. 10-1636277, 100 to 300 parts by weight of blast furnace slag fine powder, pH 12 to 12.5, and calcium oxide content 65 to 300 parts by weight based on 100 parts by weight of fine light-burnt dolomite powder. 75% by weight, a sulfate oxide content of 20 to 30% by weight, and 50 to 200 parts by weight of gypsum having a combined content of calcium oxide and sulfate oxide of 95% or more. A pile injector composition is presented.

These technologies are based on the theory of alkali-activated slag activated by alkali and sulfate stimulation by desulfurized gypsum generated as a by-product of the desulfurization process in a circulating fluidized bed boiler furnace using blast furnace slag fine powder as a main material and petro-coke as fuel as a subsidiary material. Circulating Fluidized Bed Boiler Using Coal as Fuel, High Calcium Fly Ash and Light Burned Dolomite as Expansion Material. That is, the above patents can be said to be technologies for hardening the main surface of piles by utilizing the strength development of alkali activated slag and the expansibility of high calcium fly ash in circulating fluidized bed boilers.

However, in the above technologies, free CaO present in petro-coke desulfurized gypsum and high-calcium fly ash rapidly absorbs a lot of moisture, so the initial fluidity is greatly reduced and the main fixing liquid transfer pipe is clogged. In addition, the initial strength expression is very late, and the follow-up process such as main pile construction is delayed, so it is currently not commercialized as a fixing material for the main pile.

Meanwhile, sodium bicarbonate (NaHCO ₃ ) is used as a desulfurization agent to remove _SOx generated from the flue gas line during the sintering process at the steelworks, and all dust generated after the desulfurization treatment is classified as general waste and landfilled. As a result, the expected amount of sodium bicarbonate desulfurization dust generated is close to about 100,000 tons annually, and the cost burden is high due to the continuous increase in landfill costs due to the lack of landfills.

Recently, several technologies for recycling such sodium bicarbonate desulfurization dust have been proposed.

For example, in Korean Patent Registration No. 10-1840470, 0.5 to 1,000 parts by weight of fluidized bed boiler bottom ash having a CaO content of 15 to 70% by weight and an SO ₃ content of 3 to 30% by weight based on 100 parts by weight of blast furnace slag fine powder and 0.5 to 1,000 parts by weight of fluidized bed boiler fly ash having a CaO content of 15 to 60 wt% and an SO ₃ content of 3 to 20 wt%, and a Na ₂ O content of 10 to 50 wt% and an SO ₃ content of 10 to 50 wt% Suggested eco-friendly ground grout material technology without heavy metal elution containing 0.1 to 500 parts by weight of japonica, which is generated as a by-product in the steelworks desulfurization process.

In the above technology, free CaO present in the high calcium fly ash of the in-furnace desulfurization method in the form of ultra-fine powder rapidly absorbs a lot of moisture, greatly reducing the fluidity, and at the same time, heat generation and expansion caused by the free CaO component occur, resulting in clogging of the transfer pipe. Occasionally, it is currently not commercialized as a fixing material for embedded piles.

In addition, in Korean Patent Publication No. 2016-0047101, 10 to 500 parts by weight of petroleum coke combustion material having a CaO content of 61 to 85% by weight and Na ₂ O content of 10 to 50% by weight and SO ₃ with respect to 100 parts by weight of blast furnace slag. Suggested is a binder composition containing 0.1 to 50 parts by weight of sodium sulfate generated as a by-product in a sintering process or glass manufacturing process in which the content is 10 to 50% by weight.

Since the above technology uses fine blast furnace slag powder and petroleum coke combustion ash (desulfurized gypsum) as the main materials and uses a small amount of sodium sulfate generated as a by-product in steel mills and glass manufacturing processes, it lacks economic feasibility and has a problem of late initial strength development. In addition, the petroleum coke combustion material rapidly absorbs a lot of moisture, so the fluidity is greatly reduced, and at the same time, the heat generation and expansion phenomenon caused by the free CaO component often causes the transfer pipe to be clogged. am.

In the present invention, petrocoke desulfurization gypsum and high calcium fly ash, which are by-products of desulfurization in the furnace, which have problems such as clogging and lack of strength during transport of milk liquid due to high free CaO used in the cited patents, are fundamentally excluded, and have excellent fluidity By using steelworks desulfurization process reaction by-products and circulating fluidized bed boiler bottom ash in large quantities as a stimulant for blast furnace slag fine powder, it is possible to secure fluidity and initial strength while exhibiting excellent volume stability.

Registered Patent No. 10-1377552 Registered Patent No. 10-1402877 Registered Patent No. 10-1636277 Registered Patent No. 10-1840470 Publication Patent 2016-0047101

The present invention has been made to solve the above problems, and an object of the present invention is to construct PHC piles with excellent volume stability while securing fluidity and initial strength by using a large amount of desulfurization process by-products from steel mills and power plants as stimulants for blast furnace slag fine powder. It is to provide a fixing material for the main surface.

In order to solve the above technical problem, the main surface fixing material for high-flowability PHC pile construction using a large amount of circulating resources according to the present invention is based on 100 parts by weight of type 1 cement, 100 to 2,000 parts by weight of blast furnace slag fine powder, and bicarbonate in the steel mill desulfurization process It includes 50 to 2,000 parts by weight of sodium reaction by-product, 10 to 500 parts by weight of slaked lime reaction by-product in the desulfurization process of steelworks, and 50 to 5,000 parts by weight of bottom ash discharged from the bottom of the circulating fluidized bed boiler.

In addition, it is characterized in that it further comprises 10 to 5,000 parts by weight of waste shells whose particle size is adjusted to 0.01 to 5 mm based on 100 parts by weight of the first-class cement.

In addition, 1 to 100 parts by weight of an alkali stimulant is further included in 100 parts by weight of the first-class cement, and the alkali stimulant further includes any one or a mixture of two or more of calcium hydroxide, magnesium hydroxide, potassium hydroxide, sodium hydroxide, and aluminum hydroxide. characterized by

In addition, 10 to 500 parts by weight of solid fuel fly ash is further included with respect to 100 parts by weight of the first-class cement, and the solid fuel fly ash includes general solid fuel (SRF, Solid Refuse Fuel), bio-solid fuel (BIO-SRF, It is characterized in that it is emitted from a power plant that burns Biomass-Solid Refuse Fuel).

In addition, in order to improve fluidity, it is characterized in that it further comprises 0.01 to 20 parts by weight of liquid and powder type plasticizers based on 100 parts by weight of the first type cement.

In addition, in order to prevent separation in water, it is characterized in that it further comprises 0.01 to 20 parts by weight of an insoluble in water based on 100 parts by weight of the first type cement.

According to the present invention, it is possible to provide a main surface fixing material for embedded pile construction with excellent volume stability while securing fluidity and initial strength by using a large amount of underutilized steelworks and power plant desulfurization process reaction by-products as a stimulus for blast furnace slag fine powder.

In addition, it can replace the first-class Portland cement used as a main surface fixing material for the existing embedded pile construction, thereby reducing production costs due to the reduction in the use of first-class Portland cement, as well as solving problems of natural resources and energy depletion and environmental pollution caused by carbon dioxide emission at the same time. can

Hereinafter, the main surface fixing material for high flowability PHC pile construction using a large amount of circulating resources according to the present invention will be described in detail.

The main surface fixing material for high fluidity PHC pile construction using a large amount of circulating resources according to the present invention is based on 100 parts by weight of type 1 cement, 100 to 2,000 parts by weight of blast furnace slag fine powder, 50 to 2,000 parts by weight of sodium bicarbonate reaction by-product in the desulfurization process of steel mills, , 10 to 500 parts by weight of slaked lime reaction by-products in the steelworks desulfurization process, and 50 to 5,000 parts by weight of bottom ash discharged from the lower part of the circulating fluidized bed boiler.

Although the first-class cement can secure initial strength, the ground environment can be contaminated by the elution of hexavalent chromium, etc., and it consumes a huge amount of natural resources and fossil fuels in the manufacturing process. It may be advantageous to reduce it as much as possible.

The fine powder of blast furnace slag is a by-product obtained by quenching slag in a high-temperature molten state, which is generated as a by-product in the blast furnace process, with water. When the blast furnace slag powder comes into contact with water, it forms an amorphous film and does not undergo a hydration reaction by itself, so the blast furnace slag powder is called latent hydraulic material. In order to exhibit latent hydraulic properties, the amorphous film must be destroyed.

The blast furnace slag fine powder is inspected to have a 0.045 mm (45 μm) sieve residue of less than 10%, or pulverized and classified, and is used after pulverizing slag in a water quenching furnace in which slag is quenched with water. Since the blast furnace slag fine powder consists of less than 10% of the 0.045 mm (45 μm) sieve residue, there is an advantage in that latent hydraulic properties can be exhibited by improving the activity of the particles.

It is preferable that 100 to 2,000 parts by weight of the blast furnace slag fine powder is mixed with respect to 100 parts by weight of Type 1 cement. When the blast furnace slag fine powder is less than 100 parts by weight, the amount of first-class cement is relatively increased and the initial strength is increased, but hexavalent chromium may be eluted, and economic efficiency is unfavorable. Conversely, if it exceeds 2,000 parts by weight, the initial strength is rapidly lowered and there is an excess amount of slag in which the hydration reaction has not been initiated.

The by-product of the sodium bicarbonate reaction in the steelworks desulfurization process is to produce sintered ore before the iron ore _is put into the blast furnace in the steelworks. do. Sodium bicarbonate reaction by-products are finally discharged in the form of dust containing Na ₂ SO ₄ as the main component and partially containing chlorine ions after going through a desulfurization reaction.

(Scheme 1)

<Sodium bicarbonate desulfurization reaction>

Sodium bicarbonate reaction by-products cannot be recycled in the steelworks process due to the lack of useful components such as Fe and Ca, and there is no appropriate treatment plan other than landfill disposal. However, due to the influence of the Framework Act on Resource Circulation, which has been enforced since 2018, disposal charges are incurred for landfill disposal, and consigned landfill processing costs are also rapidly increasing. Therefore, there is a need for an alternative treatment plan to reduce the landfill amount of desulfurization dust from sodium bicarbonate. However, in the case of sodium bicarbonate reaction by-products, when reacting with water, they dissolve into Na ⁺ and SO4 ^2- to maintain high pH and induce complex stimulation of alkali and sulfate, so that the hydration reaction of the blast furnace slag fine powder can be rapidly promoted in the early stage. In addition, it is easily soluble in water and has no free CaO component, so it has an effect of improving fluidity when mixed with water. In addition, since it is generated in the form of dust, it has the advantage of being usable immediately without separate processing such as crushing or crushing. Therefore, there is a possibility that the by-product of the sodium bicarbonate reaction in the steelworks desulfurization process can be used as a reaction stimulator for the blast furnace slag fine powder. In addition, since it is a material containing chlorine, chlorine ion (Cl ^- ) has the property of accelerating the hydration reaction of blast furnace slag fine powder and cement, replacing calcium chloride and sodium chloride commonly used in fields requiring initial strength in winter. can do. The sodium bicarbonate reaction by-product is preferably used in an amount of 100 to 2,000 parts by weight based on 100 parts by weight of the first type cement. If it is less than 100 parts by weight, the effect of improving rapid setting and fluidity is insufficient, and if it exceeds 2,000 parts by weight, the strength is relatively greatly reduced and whitening may occur.

In order to remove sulfur (S) contained in molten iron produced in a blast furnace such as a steelworks, the slaked lime reaction by-product of the steelworks desulfurization process is stirred after adding desulfurization additives such as high powdered lime to the top of the molten iron to remove sulfur and the desulfurization additives. The sulfur contained in molten iron is removed by promoting the reaction of In this desulfurization process, reaction by-products are generated. The slaked lime reaction by-product of the steelworks desulfurization process is composed of Ca(OH) ₂ and CaSO ₄ , CaCO ₃ and CaCl ₂ as main components, and is a strong alkaline substance with a pH of 11.5 or higher and has no free CaO component, so it has an effect of improving fluidity when mixed with water. there is. In addition, Na ⁺ component among the sodium bicarbonate reaction by-products is easily soluble in water, and leaching may occur when the hardened body is in contact with water for a long time. When used together, it has properties that can perform simultaneous roles as both a stimulant and an accelerator. The slaked lime reaction by-product is preferably mixed in an amount of 10 to 500 parts by weight based on 100 parts by weight of type 1 cement. This makes it difficult to develop initial strength.

In addition, the bottom ash discharged from the bottom of the circulating fluidized bed boiler is mixed with limestone in a circulating fluidized bed boiler that burns petro coke, coal, general solid fuel, bio solid fuel, etc. alone or in combination to desulfurize in the furnace. . In the desulfurization process of the circulating fluidized bed boiler, limestone is injected into the combustion chamber and burned together with fuel. Sulfur phosphate and limestone in the combustion gas react in the furnace to remove sulfur in the combustion gas and produce anhydrous gypsum. It is carbonated and converted to quicklime components and discharged. In particular, circulating fluidized bed boiler bottom ash burns at a temperature of about 850 ° C and has no _glassy components, so it cannot cause a pozzolanic reaction. It can be said that it has a more excellent composition as a stimulant for fine slag powder. However, unlike fly ash collected from the top, it has a large particle size and a heavy specific gravity, so when mixed with water, it improves fluidity and promotes the hydration reaction of cement and blast furnace slag fine powder. In addition, since the appearance is in the form of coarse sand rather than fine powder particles, the surface friction can be greatly improved by increasing the adhesion with the PHC pile when applied as a raw material for the main surface fixing material.

The bottom ash is preferably mixed in an amount of 50 to 5,000 parts by weight with respect to 100 parts by weight of Type 1 cement. If it is less than 50 parts by weight, the effect is not exhibited, and if it is greater than 5,000 parts by weight, the slag content is relatively reduced and the stimulant component is reduced. Excessive strength will be greatly reduced.

In addition, it is preferable to further include 10 to 5,000 parts by weight of waste shells whose particle size is adjusted to 0.01 to 5 mm based on 100 parts by weight of the first-class cement.

The waste shell is a shell remaining after collecting shellfish such as oysters, clams, and abalone, and some salt and organic matter are present in the shell, but a large amount of water and energy are required to remove it. In the present invention, separate salt and organic matter are removed It is preferable to use it immediately after going through a grinding process without a process. When waste shells are mixed in reinforced concrete, etc., if salt and organic matter are present, corrosion of the reinforcing steel and loss of strength can greatly occur. It is possible to utilize it because it is not greatly affected by the content of salt and organic matter in it.

The waste shell powder has a calcium carbonate component of 90% or more and can serve as a filler and aggregate in the main fixing material of the PHC pile of the present invention. It is preferable that the particle size of the waste shell powder is adjusted to 0.01 to 10 mm. If the particle diameter is less than 0.01mm, the cost of grinding is excessively increased, which is disadvantageous in economic efficiency, and if the particle diameter exceeds 5mm, there is a risk of clogging of the transfer pipe. In addition, since the waste shell powder has a smooth surface, it can also play a role in enhancing fluidity, and the surface friction can be greatly improved by increasing the adhesion with the PHC pile. The waste shell powder is preferably mixed in an amount of 10 to 5,000 parts by weight based on 100 parts by weight of type 1 cement. will be greatly reduced.

In addition, 1 to 100 parts by weight of an alkali stimulant is further included with respect to 100 parts by weight of the first-class cement, and the alkali stimulant further includes any one or a mixture of two or more of calcium hydroxide, magnesium hydroxide, potassium hydroxide, sodium hydroxide, and aluminum hydroxide. It is desirable to do The alkali stimulant is an industrial product and can be used as long as it has a purity of 80% or more, and serves to improve the initial strength of the main surface fixing material. In addition, since it is in the form of hydroxide (OH ^- ) ions pre-reacted with water without free CaO, it has the advantage of not adversely affecting fluidity. The alkali stimulant is preferably mixed in an amount of 1 to 100 parts by weight based on 100 parts by weight of Type 1 cement. If it is less than 1 part by weight, the effect is not exhibited, and if it is more than 100 parts by weight, it does not react with cement and blast furnace slag fine powder. The presence of a stimulant component rather lowers the strength and is disadvantageous in terms of economy.

In addition, it is preferable to further include 50 to 2,000 parts by weight of solid fuel fly ash based on 100 parts by weight of the first-class cement. The solid fuel fly ash is preferably discharged from power generation facilities that burn general solid fuel (SRF, Solid Refuse Fuel) and bio solid fuel (BIO-SRF, Biomass-Solid Refuse Fuel). Unlike coal and petro-coke, the solid fuel has a low sulfur content, so it does not mix and burn by separately adding limestone, so there is no free CaO component in the fly ash, so it does not have the property of absorbing excessive moisture. . In addition, the solid fuel combustion ash contains some chlorine components, so it is effective in enhancing the initial strength. The solid fuel fly ash is preferably mixed in an amount of 10 to 500 parts by weight with respect to 100 parts by weight of type 1 cement. If it is less than 10 parts by weight, the effect is not exhibited, and if it exceeds 500 parts by weight, the strength is relatively greatly reduced. .

In addition, it is preferable to further include 0.01 to 20 parts by weight of liquid and powder type plasticizers to improve fluidity with respect to 100 parts by weight of the first type cement. The fluidizing agent is preferably any one selected from the group consisting of naphthalene-based, melamine-based, amine-based, lignin-based, and polycarboxylic acid-based, or a mixture of two or more. If it is less than 0.01 parts by weight, there is no effect on improving fluidity, and if it exceeds 20 parts by weight, fluidity is excessively improved, and material separation may occur and economical efficiency is insufficient.

In addition, it is preferable to further include 0.01 to 20 parts by weight of a non-separating agent in water to prevent separation in water with respect to 100 parts by weight of the first-class cement. Hydroxypropyl methylcellulose (HYDROXY PROPYL METHYL CELLULOSE, HPMC), hydroxy ethyl cellulose (HYDROXY ETHYL CELLULOSE, HEC), carboxymethyl cellulose (CARBOXY METHYL CELLULOSE, CMC), ethyl hydroxyl cellulose (ETHYL HYDROXY ETHYL CELLULOSE, EHEC), polyacrylic, polysaccharide (POLY SACCARIDE), hydroxyethyl methylcellulose (HYDROXY ETHYL METHYL CELLULOSE, HEMC), polyethylene oxide (POLY ETHYLENE OXIDE, PEO), ethylene vinyl acetate (ETHYLENE VINYL ACETATE, It is preferably any one selected from the group consisting of EVA) or a mixture of two or more. If it is less than 0.01 parts by weight, there is no effect of improving the inseparability in water, and if it exceeds 20 parts by weight, the viscosity becomes excessive, making construction difficult.

Preferred examples and comparative examples of the present invention will be described below. In addition, the following examples are intended to illustrate the present invention and should not be construed as limiting the scope of the present invention.

Table 1 below shows the mixing ratio of the main surface fixing material of Examples 1 to 4 according to the present invention and the mixing ratio of Comparative Example 1 using only one Portland cement, Comparative Example 2 and Comparative Example 3 using Petro-coke desulfurized gypsum and high calcium fly ash . The water/binder ratio was performed at 68%, which is widely used in the field recently to improve the surface friction.

Table 2 below shows the performance test items and methods of the main surface fixture.

division 1 type
cement blast furnace
slag fine powder bicarbonate
salt
reaction
by-product hydroxylation
calcium
reaction
by-product Circulating Fluidized Bed Boiler Bottom Ash Oyster Shell Powder hydroxylation
calcium solid fuel
fly
Ash Petro
cokes
desulfurization
gypsum Circulating Fluidized Bed Boiler Fly
Ash Comparative Example 1 100 Comparative Example 2 40 5 55 Comparative Example 3 40 30 30 Example 1 10 40 15 15 20 Example 2 10 40 10 10 15 10 Example 3 10 42.5 15 10 20 2.5 Example 4 10 40 10 10 20 10

Experiment method note slump flow KS F 2594 Slump flow test method compressive strength KS F 2343 Uniaxial compressive strength test method

division slump
flow
(cm) Compressive strength (MPa) 3 days 7 days 28 days Comparative Example 1 40 13.23 23.23 29.34 Comparative Example 2 21 2.31 4.06 10.03 Comparative Example 3 18 3.89 5.43 9.25 Example 1 49 10.31 19.89 27.78 Example 2 45 7.33 13.43 20.23 Example 3 49 13.32 19.11 26.78 Example 4 47 11.69 17.73 24.89

(1) Slump flow test results

As a result of observing the fluidity change of the main surface fixing material, as shown in Table 3, Comparative Example 1 using type 1 cement showed 40 cm, and Examples 1, 2, 3 and Example 4 showed 45 to 49 cm, which is very much compared to Comparative Example 1. It showed good fluidity. This is because all the materials used have no free CaO component and have a smooth particle surface, so they do not absorb a large amount of water. Therefore, when used as a fixing material for the main surface of a PHC pile, it is judged that it can be well injected into the ground without clogging of the transfer pipe due to a decrease in initial fluidity.

However, in Comparative Examples 2 and 3, in which petrocoke desulfurization gypsum and high calcium fly ash, which are raw materials discharged from the desulfurization process in the circulating fluidized bed boiler furnace, were used as the main stimulant and expansion material, the initial fluidity was significantly higher than that of the main surface fixing material according to the present invention by about 25 cm or more. It was observed that the deterioration of This is because the raw materials have a high specific surface area and a rough surface to easily absorb water, and show absorption, heat generation and expansion properties due to free CaO components. In this way, when the fluidity is rapidly reduced when mixed with water, the problem of clogging of the milk liquid transfer pipe often occurs, so that it is not currently commercialized as a fixing material for the PHC pile.

(2) Uniaxial compressive strength test results

Examples 1 to 4 of the present invention showed good results, as it was confirmed that strength development of the level of 70 to 95% of Comparative Example 1 using 1 type cement was possible.

However, in the case of Comparative Examples 2 and 3, although it satisfies the uniaxial compressive strength standard of 0.49MPa (28 days) of the main surface fixing material of the ready-made pile in the LH special specification, the tip root material (Korea Road) requires a very high uniaxial compressive strength compared to the main surface fixing material. 20 MPa on the 28th based on the construction specifications, W/B 70% or less) was found to be unsatisfactory. In addition, in general, in the field, since the strength is expressed at the beginning and the PHC pile must be quickly fixed, it is judged that field application will be difficult due to the lack of initial strength required in the field.

Therefore, the PHC pile main surface fixing material of the present invention has no free CaO component, can provide a main surface fixing material for embedded pile construction with excellent volume stability while securing fluidity and initial strength, and is most widely used as a tip root and main surface fixing material. Type 1 ordinary cement can be substituted or its amount can be minimized. In addition, it can reduce production costs by reducing the amount of cement used, as well as solve the problem of natural resource and energy depletion and environmental pollution caused by carbon dioxide emission at the same time.

Claims (10)

Regarding 100 parts by weight of type 1 cement,
100 to 2,000 parts by weight of blast furnace slag fine powder;
50 to 2,000 parts by weight of sodium bicarbonate reaction by-products in the steelworks desulfurization process;
10 to 500 parts by weight of slaked lime reaction by-products in the steelworks desulfurization process;
It is a main surface fixing material containing 50 to 5,000 parts by weight of bottom ash discharged from the bottom of a circulating fluidized bed boiler,
Main surface fixing material for high fluidity pile construction, in which the slump flow test performance according to the KS F 2594 method for the main surface fixing material is 45 to 49 cm compared to 40 cm when using only type 1 cement.
According to claim 1,
Regarding 100 parts by weight of the above type 1 cement
It further comprises 10 to 5,000 parts by weight of waste shells whose particle size is adjusted to 0.01 to 5 mm, wherein the waste shells are used through a grinding process without a separate salt and organic matter removal process.
According to claim 1,
Based on 100 parts by weight of the first-class cement, 1 to 100 parts by weight of an alkali stimulant is further included,
The alkali stimulant further comprises any one or a mixture of two or more of calcium hydroxide, magnesium hydroxide, potassium hydroxide, sodium hydroxide, and aluminum hydroxide.
According to claim 1,
Main surface fixing material for pile construction, characterized in that it further comprises 10 to 500 parts by weight of solid fuel fly ash based on 100 parts by weight of the first-class cement.
According to claim 4,
The solid fuel fly ash is a main surface fixture for pile construction, characterized in that discharged from power generation facilities that burn general solid fuel (SRF, Solid Refuse Fuel) and bio-solid fuel (BIO-SRF, Biomass-Solid Refuse Fuel).
According to claim 1,
Main surface fixing material for pile construction, characterized in that it further comprises 0.01 to 20 parts by weight of liquid and powder type fluidizers based on 100 parts by weight of the first type cement in order to improve fluidity.
According to claim 6,
The fluidizing agent is any one selected from the group consisting of naphthalene, melamine, amine, lignin, and polycarboxylic acid, or a mixture of two or more main surface fixing materials for pile construction.
According to claim 1,
Main surface fixing material for pile construction, characterized in that it further comprises 0.01 to 20 parts by weight of an underwater inseparable agent based on 100 parts by weight of the first type cement in order to prevent separation in water.
According to claim 8,
The water-insoluble separating agent is hydroxypropyl methyl cellulose (HYDROXY PROPYL METHYL CELLULOSE, HPMC), hydroxy ethyl cellulose (HYDROXY ETHYL CELLULOSE, HEC), carboxymethyl cellulose (CARBOXY METHYL CELLULOSE, CMC), ethyl hydroxytyl cellulose (ETHYL) HYDROXY ETHYL CELLULOSE, EHEC), POLY ACRYLIC, POLY SACCARIDE, HYDROXY ETHYL METHYL CELLULOSE, HEMC, POLY ETHYLENE OXIDE, PEO, ETHYLENE VINYL ACETATE , EVA) main surface fixing material for pile construction, characterized in that any one selected from the group consisting of or a mixture of two or more.
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