KR20030070251A - Fiber reinforced permeating concrete block and method for manufacturing same - Google Patents

Abstract

PURPOSE: A fiber-reinforced water-permeable concrete block and its preparation method are provided, wherein the concrete block is improved in the bending strength and the water permeability and is used as a concrete interlocking block for a road or pavement and a vegetation block. CONSTITUTION: The fiber-reinforced water-permeable concrete block comprises aggregate joined by using cement as a binder, and 1-3 wt% of a mixture of an inorganic fiber and an organic fiber in the ratio of 5:5 to 9:1 by weight as a reinforcing fiber. Preferably the inorganic fiber is a glass fiber and the organic fiber is a polypropylene fiber. The concrete block has a compression strength of 240 kgf/cm2 or more, a bending strength of 50 kgf/cm2 or more, a pore ratio of 16% or more and a coefficient of water permeation of 0.6 cm/sec or more.

Description

FIBER REINFORCED PERMEATING CONCRETE BLOCK AND METHOD FOR MANUFACTURING SAME}

The present invention relates to a concrete block having excellent permeability and manufactured by mixing two kinds of reinforcing fibers in order to increase the flexural strength and a method of manufacturing the same. Specifically, the present invention relates to a fiber-reinforced water-permeable concrete block and a method for manufacturing the same, wherein the inorganic fiber and the organic fiber are used together as a reinforcing fiber.

Generally, permeable concrete blocks are manufactured by mixing fine aggregates, liquid admixtures or powder admixtures according to the function and use of cement, water, coarse aggregates, etc. There are disadvantages to losing. Such permeable concrete blocks have the most important physical properties according to their use.

Prior art of the present invention, the Republic of Korea Patent Publication No. 1993-0002274 uses cement as a binder in a permeable concrete block, and the surface of the block is polished to improve the permeability, but the flexural strength is low as 20kgf / cm ² It has a downside.

Meanwhile, Korean Laid-Open Patent Publication No. 1999-0075834 discloses concrete by mixing aggregate, cement, water, strength enhancer, reinforcing fiber, and admixture, and by vibrating with a vibrator using a molding machine in a state where the slump of concrete is 0. The present invention relates to a method for manufacturing a porous concrete block, and a porous concrete block produced thereby, comprising the steps of filling the mold into a mold and molding the mold, demolding the molded article, and curing the molded article. In this method, specifically, ∑1000 (Dongyang Cement Co., Ltd.) mainly composed of anhydrous gypsum and pozzolanic mineral components as strength enhancers was used while using commercially available polypropylene fibers as organic fibers as reinforcing fibers. The permeability coefficient of the block was 6.1-7.0 × 10 ⁻¹ cm / sec, and the flexural strength was 59-62 kgf / cm ² . However, this method has a disadvantage in that the manufacturing process is complicated because a polypropylene fiber, which is an organic fiber having low adhesion to cement, is used as a reinforcing fiber, and a strength enhancer must be separately mixed.

As such, many researchers have been making efforts to manufacture concrete blocks having excellent permeability and bending strength, but have not yet achieved satisfactory results.

Therefore, in the present invention, as a result of studies to fundamentally solve the problems such as lowering the flexural strength of the conventional water-permeable concrete, and the increase of the overall construction cost due to the application of reinforcing materials and expensive strength enhancers, inorganic fibers and organic fibers It is possible to secure the flexural strength of 50kgf / cm ² or more without using the strength enhancer, and to simplify the manufacturing equipment and process of the water-permeable concrete block without using the strength enhancer. It was completed.

According to the above object, the present invention provides a fiber-reinforced water-permeable concrete block, characterized in that in the water-permeable concrete block bonded to the aggregate by cement as a binder, containing a mixture of inorganic fibers and organic fibers as reinforcing fibers. .

In addition, in the present invention, the method comprising the steps of preparing concrete by mixing aggregate, cement, water, reinforcing fibers and admixtures, vibrating, demolding the molded article, curing the demolded molded article, inorganic type as reinforcing fibers Provided is a method for producing a fiber reinforced permeable concrete block, characterized in that a mixture of fibers and organic fibers is used.

Hereinafter, the present invention will be described in detail.

Looking at the configuration and properties of the material used to manufacture the fiber reinforced permeable concrete block in the present invention.

Aggregate used in the present invention is preferably 2.5 to 8mm in size. In addition, in order to manufacture the water-permeable concrete block of the present invention, concrete 1m ³ sugar aggregate is preferably used 1400 to 1800kg / m ³ , cement is 350 to 450kg / m ³ , the ratio of cement to aggregate is weight It is preferably about 1: 4 by reference.

The amount of water used in the present invention is about 23 to 27% of the weight of the cement.

In addition, the reinforcing fiber used in the present invention is used to improve the bending strength, and is used by mixing an inorganic fiber and an organic fiber. The inorganic fibers include glass fibers, carbon fibers, and the like, and the organic fibers include polypropylene fibers, polyamide fibers, polyethylene fibers, polyvinyl alcohol fibers, and the like. In consideration of the reinforcing effect and economical efficiency of the fiber reinforced permeable concrete block of the present invention, among these fibers, glass fibers are preferred as inorganic fibers and polypropylene fibers are preferred as organic fibers.

Inorganic fibers and organic fibers used as reinforcing fibers are preferably mixed at a mixing ratio of 5: 5 to 9: 1. In addition, the mixing amount of the reinforcing fiber is preferably about 1 to 3% based on the weight of the cement, about 0.25 to 0.75% based on the aggregate weight, and the mixing amount of the inorganic fiber in the mixing state is 3.6 to 10.8 per unit volume of the concrete. kg / m ^3, and the incorporation amount of the organic fiber is 0.4 to 1.2 kg / m ³ per unit volume of concrete.

Admixtures used in the present invention are classified according to the effect on the amount of air in the concrete, the amount of water used (unit quantity), the setting time, the initial curing rate, and the like, and these admixtures include an AE agent (Air Entraining Agent) for improving durability and Reducing agents to reduce the number of units is mainly used, in addition to shrinkage reducing agent (cracking inhibitor), setting time control agent, waterproofing agent and the like. The amount of admixture used in the present invention is preferably about 0.15 to 0.35% by weight based on the weight of the cement used.

The fiber-reinforced concrete block according to the present invention is prepared by injecting the compounded concrete as described above into the mold placed on the vibrator of the vibration molding machine, vibration molding for a predetermined time, and then demolding.

Curing after demolding, after the initial curing time 2 to 4 hours under atmospheric pressure, the temperature should be raised to 20 ° C. or less every hour and maintained at 60 ° C. to 70 ° C. for 4 to 8 hours, wherein the total curing time is 6 to 12 hours, Relative humidity should be maintained above 90%. The reason why the curing temperature does not immediately rise to the maximum temperature during curing is that if the temperature in the curing chamber changes rapidly, it may cause product cracking and strength degradation. Similarly, when opening the curing room door after curing, if the temperature difference between indoor and outdoor is severe, care should be taken not to give a sudden temperature change to the product because the cold air causes the product to crack and the product is easily deformed. The cured product performs natural curing for 7 days or more to complete the permeable concrete block of the present invention.

The fiber-reinforced permeable concrete blocks produced by the present invention may contain about 16% or more continuous voids, and the flexural strength of the concrete blocks during natural curing for 7 days or more after the completion of steam curing may exhibit 50kgf / cm ² or more. have.

The fiber-reinforced water-permeable concrete blocks manufactured by the method of the present invention is the compression strength more than 240kgf / cm ^2, and bending strength is more than 50kgf / cm ^2, the porosity is at least 16%, a permeability coefficient be at least 0.6cm / sec .

The fiber-reinforced permeable concrete block produced by the present invention has improved flexural strength as compared to the conventional permeable concrete block, has excellent permeability, so that rainfall and rainwater are well transmitted, and the water penetrated into the concrete block is naturally drained. It is also suitable for ecosystem protection and environmental protection because it exhibits ventilation and dehydration effects. Such a water permeable concrete block of the present invention is useful for use as a concrete interlocking block and vegetation block for a walkway that requires excellent permeability and high bending strength.

Hereinafter, the present invention will be described in detail by way of examples.

However, the following examples are merely to illustrate the invention, but the content of the present invention is not limited by the following examples.

In the embodiment of the present invention, cement used a specific type 1 portland cement having a specific gravity of 3.15 and a powder degree of 3,300 cm ² / g, and an aggregate having a specific gravity of 2.58 and an aggregate size of 2.5 to 8.0 mm. As the admixture, Confiux-SP600S (standard type of high performance reducer) of Daehwa Corporation was used.

Inorganic fibers used in the present invention are glass fibers (glass fiber SEH51, Concrete Co., Ltd.), and organic fibers are polypropylene fibers (Super Strong Corn Fiber, Inc.). Same as

Characteristics of Reinforcing Fibers Used in the Present Invention Kinds Fiber diameter (mm) importance Modulus of elasticity (× 10 ^-3 kgf / cm ² ) Tensile strength (kgf / cm ² ) Fiberglass 6.0 2.54 73.5 31,000 Polypropylene fiber 19.0 0.91 35.0 3,500 ~ 7,700

The material combinations used in the following Comparative Examples and Examples of the present invention are shown in Table 2 below.

Material blending of fiber reinforced permeable concrete blocks Item Classification Cement amount per unit of concrete volume (kg / m ³ ) Aggregate content per unit volume of concrete (kg / m ³ ) Water (% by weight of cement) Admixture (% by weight to cement) Reinforcing fiber content per unit of concrete (kg / m ³ ) Fiberglass Polypropylene fiber Comparative Example 1 400 1600 25.0 0.3 0 0 Comparative Example 2 0 4 Comparative Example 3 4 0 Example 1 3.6 0.4 Example 2 7.2 0.8 Example 3 10.8 1.2

<Comparative Example 1>

Dry mix the cement and aggregate in the amounts shown in Table 2 for 60 seconds, then add the appropriate amount of water and admixture (Confiux-SP600S (standard of high performance reducer), Daehwa Co., Ltd.) The mixed concrete mixture was put into a mold placed on the vibrator of the vibration molding machine, and the molded article was manufactured by vibration molding and demolding at 5600 rpm for 3-7 seconds.

After initial curing for 2 to 4 hours at atmospheric pressure, the temperature was raised to 20 ° C. or lower every hour to reach a temperature of 60 ° C. to 70 ° C., and then maintained at a relative humidity of 90% or more for 4 to 8 hours. The cured product was then naturally cured for at least 7 days.

<Comparative Example 2>

Performed as in Comparative Example 1, when preparing a concrete blend, using a 4kg / m ³ polypropylene fiber as a reinforcing fiber was prepared a fiber reinforced permeable concrete block.

<Comparative Example 3>

Performed as in Comparative Example 1, when preparing a concrete blend, using a glass fiber 4kg / m ³ as a reinforcing fiber was prepared a fiber reinforced permeable concrete block.

<Example 1>

Performed as in Comparative Example 1, when preparing a concrete blend, using a 9: 1 mixture of 4kg / m ³ of glass fiber and polypropylene fiber as a reinforcing fiber was prepared a fiber reinforced permeable concrete block according to the present invention.

<Example 2>

The concrete block was prepared in the same manner as described in Example 1, except that the amount of reinforcing fibers (9: 1 mixture of glass and polypropylene fibers) was 8 kg / m ³ , which is 2.0% of 400 kg / m ³ cement. Prepared.

<Example 3>

The concrete block was prepared in the same manner as described in Example 1 except that the amount of reinforcing fibers (9: 1 mixture of glass and polypropylene fibers) was set to 12 kg / m ³ , which is 3.0% of 400 kg / m ³ of cement. Prepared.

<Measurement of Physical Properties of Manufactured Concrete Block Specimen>

The compressive strength, flexural strength, permeability coefficient, and porosity of the concrete block specimens cured according to the comparative examples and examples were measured.

Compressive strength

The compressive strength of the concrete block was measured in accordance with the concrete compressive strength test method specified in KS F 2405, and then the compressive strength of the test body was calculated according to the following equation (1).

Where σ _c is the compressive strength (kgf / cm ² ), P is the maximum load (kgf), and A is the cross-sectional area of the specimen (cm ² ).

Flexural strength

The flexural strength was measured by the maximum load in accordance with the flexural strength test method of concrete prescribed in KS F 2408, and then the flexural strength of the test specimen was calculated by the following equation.

Where _b is the flexural strength (kgf / cm ² ), P is the maximum load (kgf), l is the span (cm), b is the width of the fracture section (cm), and d is the height of the fracture section ( cm).

Permeability coefficient

The permeability coefficient of the test body was measured according to the permeability coefficient test method of porous concrete of the Eco Concrete Research Committee of the Japan Concrete Engineering Association, and was calculated by the following Equation 3.

Where K is the permeability coefficient (cm / sec) of the porous concrete, H is the height of the test specimen (cm), Q is the permeability (cm ³ ) from time t ₁ to t ₂ , and h is the water level difference (cm) T ₂ -t ₁ is the measurement time (sec), and A is the cross-sectional area of the test object (cm ² ).

Porosity

The porosity of the test body was measured according to the porosity test method of porous concrete of the Eco Concrete Research Committee of the Japan Concrete Engineering Association, and was calculated by the following Equation 4.

Where A is the porosity of the porous concrete (%), W ₁ is the weight in water of the test body (%), W ₂ is the weight in air (g) after 24 hours of indoor standing of the test body, and V is the volume of the test body ( cm ³ ).

Table 3 summarizes the results of measuring the compressive strength, flexural strength, permeability coefficient, and porosity of the concrete block test body manufactured by Comparative Examples and Examples according to the test method.

Physical property measurement result of fiber reinforced permeable concrete block specimen of the present invention division Compressive strength (kgf / cm ² ) Flexural strength (kgf / cm ² ) Permeability coefficient (cm / sec) Porosity (%) Comparative Example 1 260 39 0.95 19.7 Comparative Example 2 241 45 0.85 17.1 Comparative Example 3 250 52 0.99 19.7 Example 1 249 50 0.98 19.8 Example 2 251 53 0.72 18.1 Example 3 245 57 0.63 16.0

According to the measurement results of the above properties, when the reinforcing fibers were mixed according to the present invention, the compressive strength of the concrete block was slightly lower than that of Comparative Example 1 in which the reinforcing fibers were not mixed at all. It was found to meet all of the maximum specified values of 240 kgf / cm ^{2 and} above.

The flexural strength was 39 kgf / cm ^{2 in} the case of Comparative Example 1, in which no reinforcing fiber was mixed, 45 kgf / cm ^{2 in} the case of Comparative Example 2 in which only the polypropylene fiber was incorporated into the reinforcing fiber, and the glass fiber was mixed into the reinforcing fiber. In the case of Example 3, 52 kgf / cm ² was shown. Therefore, when polypropylene fiber alone is used as the reinforcing fiber, it is judged that it is difficult to use it as a concrete block because the bending strength is 50 kgf / cm ² or less. In Comparative Example 3, the bending strength is satisfied, but the glass fiber is expensive, so it is economical. Considering this, there is a problem that the unit price of the product increases.

On the other hand, in Examples 1 to 3 in which a mixture of inorganic fibers and organic fibers were mixed as the reinforcing fibers, the flexural strength of 50 to 57 kgf / cm ² was shown. Therefore, the bending strength was 25 to 42% due to the incorporation of the reinforcing fibers as compared to Comparative Example 1. It can be seen that the degree is improved, and also as the incorporation rate of the reinforcing fiber increases (Example 1 <Example 2 <Example 3), the bending strength is further improved.

On the other hand, the permeability coefficient of the embodiment performed in the present invention was 0.63 ~ 0.98 cm / sec, it was observed to ensure the porosity more than 16%.

Therefore, as a result of measuring the basic physical properties of the concrete block test specimen according to each embodiment, when mixing a mixture of inorganic fibers and organic fibers as the reinforcing fibers to ensure excellent water permeability by maintaining a sufficient permeability coefficient and porosity as water-permeable concrete The flexural strength of the concrete block was significantly improved to 50 kgf / cm ² or more.

In accordance with the present invention, by mixing the inorganic fibers and organic fibers as a reinforcing fiber in the concrete blend can be prepared a permeable concrete block with excellent permeability and greatly improved bending strength, the permeable concrete block is interlocking concrete interlocking It can be used for the manufacture of concrete secondary products such as blocks and revetment blocks.

Therefore, when the fiber reinforced permeable concrete block disclosed in the present invention is applied to concrete secondary products such as interlocking blocks or rafting blocks, rainwater, rainfall, etc., flow out onto the surface as it flows or flow into rivers or rivers through drains. It will be able to improve various environmental problems such as desertification of the ground and destruction of the natural ecosystem due to the flooding of the city and the destruction of the ground life due to the depletion of the groundwater caused by the depletion of the groundwater.

Claims (6)

A water-permeable concrete block bonded to aggregates using cement as a binder, wherein the fiber-reinforced water-permeable concrete block comprises a mixture of inorganic fibers and organic fibers as reinforcing fibers. The method of claim 1, Fiber-reinforced permeable concrete block, characterized in that the inorganic fibers are glass fibers, the organic fibers are polypropylene fibers. The method of claim 1, The mixing weight ratio of the inorganic fiber and the organic fiber is 5: 5 to 9: 1, the content of the reinforcing fiber is fiber reinforced permeable concrete block, characterized in that 1 to 3% based on the weight of the cement. The method of claim 1, Fiber reinforced permeable concrete block characterized in that the compressive strength is more than 240kgf / cm ² , the flexural strength is more than 50kgf / cm ² , the porosity is 16% or more, the permeability coefficient is 0.6cm / sec or more. The method according to claim 1 or 4, Fiber-reinforced permeable concrete block, characterized in that it is used as a concrete interlocking block or vegetation block for sidewalks. A method of manufacturing a fiber reinforced permeable concrete block comprising mixing aggregate, cement, water, reinforcing fibers, and admixture to produce concrete, vibrating, demolding the molded article, and curing the demolded molded article. A method for producing the fiber reinforced permeable concrete block according to claim 1, wherein a mixture of an inorganic fiber and an organic fiber is used as the fiber.