KR20100133118A - Concrete block manufacture method to use refreshing aggregate - Google Patents

Abstract

PURPOSE: A method for manufacturing a stiff consistency concrete block is provided to prevent the breakage of the concrete block and reinforce a freezing and thawing preventive property using waste concrete based recycled aggregate. CONSTITUTION: Waste concrete based recycled aggregate, sand, cement, and gypsum are introduced into a mixer. A mixing operation is performed(S1). One or two of a water repellent agent, a waterproof agent, and a water reducing agent are mixed to prepare a solution. The solution is sprayed into the mixer in order to prepare a dry composition(S2). The dry composition is introduced into a block mold. A mixture of water, and the water repellent agent or the waterproof agent is coated on the surface of a molded block(S4).

Description

Concrete block manufacture method to use refreshing aggregate}

The present invention relates to a method for manufacturing a bibimb concrete block using recycled aggregate, and more specifically, using recycled aggregate pulverized waste concrete, which is environmentally friendly, increases compressive strength and freeze-thawing resistance, and decreases absorption rate and prevents whitening phenomenon. The present invention relates to a method for producing a non-beam concrete block using recycled aggregate.

Typically, the retaining wall block manufacturing method is prepared by mixing the binder (cement) and aggregate (sand and stone powder), water-reducing agent, water, vibration and compression molding after the injection into the block molding machine and atmospheric pressure curing.

However, most of the conventional retaining wall blocks have a compressive strength of 180 to 240 kg / cm 2 and an absorption rate of 5 to 12%, which is easily broken due to low strength during construction and structural risks caused by freeze thawing and whitening during use. Many problems have arisen, such as deterioration of landscaping.

In addition, considering the environmentally friendly performance of the near-industrial, research and development has been made to replace the aggregate with the recycled aggregate crushed waste concrete, but the recycled aggregate has a lower compressive strength, higher absorption rate than natural aggregate, Since impurities are leaked to the surface of the retaining wall block after manufacture, they are not suitable for producing concrete products.

Therefore, in the conventional patent registration No. 0324249, the surface of the permeable concrete packaged for permeable concrete using residual particles of 1.5 mm or less, the surface state is clean and the pore clogging is small and the water permeability is continued, as well as the material The technology about the packing method of the thin-film permeable concrete thin layer for easy handling and easy construction has been registered.

However, the above-described technique uses one or two or more of crushed aggregate, crushed waste concrete, recycled aggregate, slag as aggregate instead of aggregate, and has a single grain coarse silica powder, waste gypsum powder, stone powder, glass At least one mixture of powder and waste tire powder is used as the fine aggregate, but the fine aggregate added on the aggregate only serves as the fine aggregate filling the space between the aggregates, and the compressive strength Low, high absorption rate, and was not followed to solve the problems caused by using the crushed waste concrete aggregate, which flows into the retaining wall block surface after manufacture.

Accordingly, the present invention has been conceived to solve the above problems, and more particularly, to provide a method for producing bibim concrete block using recycled aggregates to improve the compressive strength and to enhance the low absorption rate and freeze-thawing resistance and to prevent whitening phenomenon For the purpose of

Features of the present invention to achieve this object,

25 to 50% by weight of recycled concrete, 25 to 50% by weight of sand, 15 to 25% by weight of cement, and 1 to 5% by weight of gypsum are added to the mixer. Mixing for 4 minutes to form a dry mixture (S1); On the basis of 100 parts by weight of the dry mixture, a solution of one or two or more of 0.1 to 3 parts by weight of water repellent, 0.1 to 3 parts by weight of water repellent, and 0.1 to 3 parts by weight of water reducing agent is added to 8 to 12 parts by weight of water at 4 to 15 ° C. Mixing the mixture for 2 to 8 minutes while spraying the inside of the blender to form a dry composition (S2); Injecting the dry composition into a block molding machine and molding for 3 to 10 seconds at a vibration of 1000 to 12000 rpm and a pressure of 100 to 200 kg / cm 3 (S3); Spray coating a solution of a water: water repellent or waterproofing agent in a ratio of 10: 1 on the molded block surface (S4); The coated retaining wall block is put into a curing chamber and steam curing step (S5); characterized in that it is manufactured through.

At this time, the waste concrete recycled aggregate is characterized in that the water: water-soluble phenol resin ratio is prepared by drying after impregnation for 5-15 seconds in a water tank mixed with 10: 1.

In addition, the kneading step (S1) is characterized in that the kneading by putting into the mixer in the order of recycled aggregate, sand, cement, gypsum.

In addition, the gypsum is characterized by using any one of anhydrous gypsum (CaSO4), dihydrate gypsum (CaSO4 2H2O), hemihydrate gypsum (CaSO4 1 / 2H2O).

In addition, the steam curing is put into the curing room for 2 hours to stand, the temperature rising step for heating 100 ~ 160 minutes to 60 ~ 70 ℃ at room temperature, the isothermal step for heating 400 ~ 540 minutes at 60 ~ 70 ℃, Characterized in that it consists of a temperature reduction step of 100 ~ 160 minutes at 60 ~ 70 ℃ to room temperature.

According to the above constitution and action, the present invention is impregnated with water-soluble phenolic resin into the recycled aggregate by the waste concrete recycled aggregate pretreatment process, and the fine powder cement and gypsum are tightly adhered to the waste concrete recycled aggregate and the sand surface by the kneading process. As the compressive strength is improved, breakage due to strength decrease is prevented in manufacturing and constructing the concrete product including the retaining wall block, and in particular, the absorption rate is lowered so that the variation of the compressive strength after freeze-thawing is reduced, resulting in structural safety. As it is secured, whitening is prevented.

In addition, by using recycled aggregates, it is effective to reduce costs and to be environmentally friendly.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram sequentially showing a method for producing a bibimb concrete block using recycled aggregate according to the present invention, Figure 2a to 2b is a photograph showing the water repellent performance test state of the specimen of the present invention and the comparative example.

The present invention relates to a method for producing old bibimb concrete block using recycled aggregate, wherein the method for producing old bibimb concrete block using recycled aggregate is a kneading step (S1), a step of forming a dry composition (S2), molding (S3) ), Spray coating step (S4), steam curing is produced through the step (S5), according to the detailed step-by-step description will be described later.

1. Kneading stage

Kneading step (S1) according to the present invention is 25 ~ 50% by weight of sand, 25 ~ 50% by weight of sand, 15 ~ 25% by weight of cement, 1 ~ 10mm of recycled concrete with a particle size of 1 ~ 10mm Add 5% by weight to a blender and mix for 1 to 4 minutes to form a dry mixture.

At this time, the order of feeding into the blender is kneaded by adding recycled aggregate, sand, cement, and gypsum in order of the largest particle size, thus preventing cement and gypsum in the form of fine powder having a relatively small particle size from sticking to the inside of the mixer drum. do.

Then, the recycled aggregate and sand, cement, gypsum rubbed with each other during the mixing through the mixer, the cement with small particle size, the gypsum is adhered to the recycled aggregate with a large particle size, sand surface to form a coating surface.

In addition, the recycled aggregate is used by drying after impregnation for 5 to 15 seconds in a water mixed with water: water-soluble phenolic resin ratio of 10: 1 particles of 1 ~ 10mm particle size washed among the crushed waste concrete, forming step to be described later In (S3), the destruction of the waste concrete recycled aggregate by strong vibration and compression is prevented, and the fine powder is removed from the surface of the recycled aggregate in the kneading step (S1) by removing impurities on the surface of the recycled aggregate while preventing the decrease in strength of the molded body. There is an advantage to improve the fixing rate of cement and gypsum.

Here, the water-soluble phenolic resin is a one-component water-soluble phenolic resin of resol & modified resol type. The mixture mixed with water should penetrate into the recycled concrete aggregate and be completely dried.

In addition, problems such as high absorption rate, self-strength decrease phenomenon and the outflow of impurities appear as a problem when using waste concrete recycled aggregates, such as the mixture of the above-mentioned water-soluble phenolic resin and gypsum added together with water repellent or waterproofing material for bibim concrete which will be described later. As a result, absorption rate is reduced, compressive strength is improved, and capillary tubes and open pores are blocked to prevent precipitation of impurities.

In addition, gypsum is hydrated by using any one of anhydrous gypsum (CaSO ₄ ), dihydrate gypsum (CaSO ₄ 2H ₂ O) and hemihydrate gypsum (CaSO ₄ 1 / 2H ₂ O) having a powder level of 3000 to 5000 kg / cm 3. The hydration product is increased by improving the reactivity of the compound. As an example, hydrated gypsum produces ettingite minerals during hydration reactions, and the ettringite minerals increase the amount of hydration products that densify the hardening body while increasing the hydration reactions, resulting in capillary and open pores. Since the filling is prevented from the strength degradation caused by the use of recycled aggregate.

Herein, the ethrinzite mineral is a needle-like crystal that has the property of expansion, and then the transitioned monosulfate hydrate has the property of shrinkage, which may be affected by concrete cracking, and thus it is necessary to control the amount of gypsum used. As a result of the test to confirm the amount of gypsum used, the amount of gypsum added is preferably 2% by weight.

TABLE 1

On the other hand, only the addition of gypsum has a limit on the control of the absorption rate, and by further adding a mixture of the water repellent material and the waterproofing material for the bibim concrete in the step (S2) of forming a dry composition described later, capillary pores and open pores of the cured body are added. By controlling the movement of water through the capillary and open pores by blocking, to prevent freeze-thaw resistance and whitening phenomenon due to the decrease in absorption rate.

2. The step of forming a dry composition

The step (S2) of forming a dry composition according to the present invention is based on 100 parts by weight of the dry mixture, based on 100 parts by weight of water from 4 to 15 parts by weight of 0.1 to 3 parts by weight of water repellent, 0.1 to 3 parts by weight of water repellent, concrete (concrete) Ordinary additives for improving the strength) Mix 2 to 8 minutes while spraying a solution of one or two or more of 0.1 to 3 parts by weight into the mixer.

At this time, when the temperature of the water falls below 4 ° C, the curing of the cement is delayed or stopped, and when the temperature rises to 20 ° C or more, the curing speed is increased, resulting in insufficient molding time due to the lack of working time due to the step of forming (S4) described later. Therefore, preferably the temperature of the water should be maintained or managed at 10 ~ 15 ℃

Here, the water-repellent material mixed with water is a water-soluble silicone emulsion, has excellent penetration and water repellency, high resistance to penetration of moisture, and breathability, and internal moisture is discharged in the form of vapor, preventing whitening and propagation of microorganisms, In addition, even in high temperature steam curing, it is not discharged like water, but remains inside the cured body, and blocks open pores and capillaries to block water movement inside the cured body, thereby improving freeze-thawing resistance and whitening that occurs on the surface. Not only can it be prevented, but it also improves the properties (absorption rate, compressive strength).

In addition, the waterproofing material is SB Latex, it is freely mixed with water, it is solidified in the concrete serves to block the open pores and capillaries to prevent absorption decrease and whitening, and to increase the compressive strength.

As the mixture is sprayed while spraying evenly for 2 to 8 minutes, the cement and gypsum coated on the recycled aggregate and the sand surface are mixed in a state of being peeled off in the kneading step (S1).

3. Forming Step

In the forming step (S3) according to the present invention, the dry composition is put into a block molding machine and molded for 3 to 10 seconds at a vibration of 1000 to 12000 rpm and a pressure of 100 to 200 kg / cm 3. In the dry composition, the particles are densely arranged by vibration and closely contact each other by the molding pressure to form an integrated block.

4. Spray coating step

Spray coating step (S4) according to the invention spray coating a solution of a water: water repellent or waterproofing agent in a ratio of 10: 1 on the molded block surface. In the forming step (S3), the surface of the molded body is sprayed onto the demolded block by spraying one of water and a water repellent material or a solution mixed with water and a water repellent material to prevent water such as rainwater from penetrating into the block. It also prevents the rapid evaporation of moisture while transporting the demolded block to a curing room to be described later or into the curing room, thereby achieving stable curing of the block.

5. Steam curing step

Steam curing step (S5) according to the present invention is put the coated retaining wall block in the curing chamber and steam curing. Steam curing is placed in a curing room for 2 hours to stand, an elevated temperature step for heating 100 to 160 minutes from 60 to 70 ℃ at room temperature, an isothermal step for heating 400 to 540 minutes at 60 to 70 ℃, 60 to 70 It consists of a temperature reduction step for 100 to 160 minutes at room temperature to ℃.

Here, the stationary step is a natural curing while suppressing the dehydration of the molded block to prevent the occurrence of cracks due to the temperature rise in the subsequent step of the temperature increase step, the stationary step is made inside the curing room to prevent the dehydration phenomenon. In addition, the temperature raising step gradually raises the temperature to prevent crack generation of the block due to the rapid temperature rise, and the isothermal step is a normal curing step, and the temperature reduction step contracts the block due to the rapid temperature drop. In order to prevent the temperature is gradually reduced to room temperature.

[Example]

Waste concrete recycled aggregate having a particle size of 1 ~ 10mm is impregnated for 5-15 seconds in a water tank containing a water: water-soluble phenolic resin ratio of 10: 1, dried to prepare anhydrous dry state,

The pretreated recycled aggregate (1 ~ 10mm aggregate) 390kg, sand 390kg, cement (blast furnace slag cement) 200kg, anhydrous gypsum (powder more than 3000kg / ㎠) in order to put in a mixer for 2 minutes kneading Then, a mixture of 50 liters of water (water supply), 2.5 liters of water repellent (water-soluble silicone oil), 2.5 liters of waterproofing material (SB Latex), and 1 liter of water sensitizer (naphthalene) was mixed into the blender for 4 minutes while being mixed. To create.

Subsequently, the dry composition is introduced into a molding machine and demoulded by molding at a vibration of 1000 to 12,000 rpm for 5 sec at a pressure of 100 to 200 kg / cm 2, and water and a water repellent agent or water and a waterproofing agent on the demolded block surface at a ratio of 10: 1. Spray-coated the mixed solution, and then undergoes a steam curing step, the steam curing cycle is put into the curing chamber to the stationary; 2hr, elevated to 65 ℃; Isothermal at 2 hrs, 65 ° C .; 8 hrs, reduced to room temperature; After 2hr, block production is completed.

In order to compare with the conventional block (comparative example) of the block manufactured by the above-described method, the test results of cutting three specimens of 50 × 50 × 50mm square in the direction perpendicular to the block molded body are shown in Table 2 below. same.

TABLE 2

As described above, the block of the present invention has a significantly lower absorption rate (see FIGS. 2A to 2B), a higher curing post-strength strength, and a less variation in compressive strength after freeze-thawing, as compared with the comparative example. Whitening is also prevented.

1 is a block diagram sequentially showing a method of manufacturing a bibimb concrete block using recycled aggregate according to the present invention.

Figure 2a to 2b is a photograph showing the water repellent performance test state of the specimen of the present invention and the specimen of the comparative example.

Claims (5)

25 to 50% by weight of recycled concrete, 25 to 50% by weight of sand, 15 to 25% by weight of cement, and 1 to 5% by weight of gypsum are added to the mixer. Mixing for 4 minutes to form a dry mixture (S1); On the basis of 100 parts by weight of the dry mixture, a solution of one or two or more of 0.1 to 3 parts by weight of water repellent, 0.1 to 3 parts by weight of water repellent, and 0.1 to 3 parts by weight of water reducing agent is added to 8 to 12 parts by weight of water at 4 to 15 ° C. Mixing the mixture for 2 to 8 minutes while spraying the inside of the blender to form a dry composition (S2); Injecting the dry composition into a block molding machine and molding for 3 to 10 seconds at a vibration of 1000 to 12000 rpm and a pressure of 100 to 200 kg / cm 3 (S3); Spray coating a solution of a water: water repellent or waterproofing agent in a ratio of 10: 1 on the molded block surface (S4); The coated retaining wall block is put into a curing room and steam curing step (S5); Old bibimb concrete block manufacturing method using a recycled aggregate, characterized in that produced through. The method of claim 1, The waste concrete recycled aggregate is a method for producing bibim concrete block using recycled aggregate, characterized in that the water: water-soluble phenolic resin ratio is prepared by drying after impregnation for 5 to 15 seconds in a water tank mixed with 10: 1. The method of claim 1, The kneading step (S1) is a recycled aggregate, sand, cement, gypsum concrete block manufacturing method using recycled aggregates, characterized in that the kneading by mixing into the mixer in order. The method of claim 1, The gypsum is a non-beam concrete block manufacturing method using recycled aggregate, characterized in that using any one of anhydrous gypsum (CaSO4), dihydrate gypsum (CaSO4 2H2O), hemihydrate gypsum (CaSO4 1 / 2H2O). The method of claim 1, The steam curing is put into a curing room for 2 hours to stand, and the temperature rising step for heating 100 ~ 160 minutes to 60 ~ 70 ℃ at room temperature, the isothermal step for heating 400 ~ 540 minutes at 60 ~ 70 ℃, 60 ~ Method for producing a bibim concrete block using recycled aggregate, characterized in that the temperature reduction step to reduce the temperature to 100 ~ 160 minutes at 70 ℃.

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