KR101150458B1 - Environmental friendly fiber-reinforced concrete - Google Patents

Abstract

PURPOSE: An environmentally-friendly fiber-reinforced concrete is provided to improve slump and mechanical properties by including kenaf fiber. CONSTITUTION: An environmentally-friendly fiber-reinforced concrete includes 0.3-3kg of kenaf fiber per 1m^3 of cement mixture. The cement mixture comprises30-60 parts by weight of water, 100-300 parts by weight of fine aggregate, 150-400 parts by weight of coarse aggregate, and 0.1-5 parts by weight of an admixture. The average length of the kenaf fibers are 0.1-2cm. A slump values which are measured by KS F 2402 rules for the fiber reinforced concrete satisfies equation 1 which follows. Equation 1: Initial slump value(mm) -15mm<= slump value(mm) <= initial slump value(mm) +15mm. In equation 1, the slump value is a measured slump value 30 minutes after manufacturing unsolidified concrete.

Description

Environmental friendly fiber-reinforced concrete

The present invention relates to fibre-reinforced concrete, and more particularly, to an environmentally friendly fibre-reinforced concrete that can improve the overall mechanical properties of concrete while using natural fibers other than wire mesh or artificial fibers.

As the properties required for concrete are diversified due to the recent development of the building industry, significant progress has been made in terms of performance on the basic properties of concrete and the compressive strength after hardening. However, concrete takes time to develop strength and is weak in tension. There are problems such as brittleness and occurrence of plastic shrinkage cracking at the initial stage of casting. These cracks can lead to severe structural problems, as well as deterioration in durability and damage to the appearance, as well as corrosion when the rebar is exposed to air or moisture due to the cracks.

There are four types of cracking factors that occur in concrete structures such as material factors, construction factors, structural factors, and environmental factors. Among them, plastic shrinkage that occurs in the early stages of casting due to the complexity of materials and construction factors. The crack causes tensile stress on the surface due to the confinement of the internal concrete that is not dried, and if the initial tensile strength of the concrete is exceeded, cracking occurs and the durability of the concrete decreases.

As an alternative method, conventionally, the wire mesh is mixed with concrete, but the reinforcement effect of the increase of the city park price and the wire mesh due to the sudden increase in the cost of steel such as reinforcing bars are recently verified. There are problems such as unclearness, existence of difficult construction part of wire mesh, and air delay.

Accordingly, in order to improve and reinforce the mechanical properties of concrete by adding fibers instead of wire mesh, fiber reinforced concrete (FRC), in which discontinuous and single-phase fibrous materials are dispersed in concrete, is frequently used. It is a trend, and the trend of being used a lot recently, such as the convenience of construction, economics. However, depending on the type, shape and mixing rate of the fiber, the dispersion force problem due to the fiber ball phenomenon occurs, the adhesive strength with the cement paste is insufficient, resulting in a decrease in strength, and the surface finish due to hair exposure during finishing Difficulty, workability (workability) problem due to the reduction of slump occurs, and also there is a difference in the mechanical performance effect such as crack resistance, there is a problem that must be determined the selection of the optimized fiber and the mixing ratio according to the application.

In addition, artificial fibers such as polypropylene fiber, steel fiber, and nylon fiber are widely used as reinforcing fibers. However, in recent years, interest in natural fibers that can be naturally produced without being harmful to the human body has been increasing. The research and development of fiber reinforced concrete is insufficient.

The present inventors endeavored to develop a new environmentally friendly fiber reinforced concrete, the introduction of the sheep was found to be able to produce concrete that is environmentally friendly and excellent mechanical properties, and completed the present invention. In addition, by knowing the optimum usage and conditions of use of horses, the present invention was completed.

Eco-friendly fiber-reinforced concrete of the present invention for solving the above problems is characterized in that it comprises a cement mixture and hemp fiber.

Eco-friendly fiber reinforced concrete of the present invention including a sheep is not only improve the concrete slump, but also excellent mechanical properties such as compressive strength, tensile strength, bending strength, and also excellent mechanical properties such as dry shrinkage length change rate, Since the rate of change in drying shrinkage length is small according to the elapsed time, it is possible to prevent plastic shrinkage cracking due to material factor, which is a cracking factor of concrete structures.

Each of A and B of FIG. 1 is a picture of the hemp fiber and jute fiber used in the embodiment of the present invention.
A and B of Figure 2 is a pulp fiber and wood fiber picture used in the embodiment of the present invention.
Each of A and B of FIG. 3 is a photo of polypropylene fiber and nylon fiber used in the embodiment of the present invention.
4 is a macro-synthetic fiber picture used in the embodiment of the present invention.

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

Eco-friendly fiber-reinforced concrete of the present invention is characterized in that it comprises a cement mixture and sheep horse fibers.

Kenaf is a plant native to Africa and India. Its stem is straight, 3 ~ 5m high, with fine hairs, with hook-like protrusions between nodes. Sheave fibers are fibers that are obtained by fermenting sheep and are tough and somewhat rough. The length of the hemp fiber is about 22cm and has been generally used as a sack, fishing net, rope, paper material, etc. By introducing this as a concrete reinforcement, there is a feature of the present invention to provide an environmentally friendly fiber reinforced concrete.

In the present invention, it is preferable to use the fleece fiber having an average length of 0.1 to 2 cm, more preferably 0.5 to 1 cm, and when less than 0.1 cm, the fiber length is too short to obtain sufficient brittleness. If it is greater than 2 cm, fiber ball phenomenon may occur, so it is preferable to use within the above range.

In addition, the fiber of the sheep is preferably included in the fiber reinforced concrete of the present invention, 0.3 to 3 kg / ㎥, more preferably 0.5 to 2 kg / ㎥. Here, there may be a problem that the mechanical properties of the desired concrete can not be obtained because the amount is less than 0.3 kg / ㎥ is too small, and when used in excess of 3 kg / ㎥ increases the mechanical properties of the concrete according to the increase in the amount of use If there is no, it is preferable to use within the said range.

The cement mixture which is one of the fiber reinforced concrete components of the present invention may include cement, fine aggregate, coarse aggregate, admixture and water. In this case, although not particularly limited, the cement mixture contains 30 to 60 parts by weight of water, 100 to 300 parts by weight of fine aggregate, 150 to 400 parts by weight of coarse aggregate, and 0.1 to 5 parts by weight of admixture with respect to 100 parts by weight of cement. good.

The cement is not particularly limited, but at least one portland cement (KS L 5201) selected from one kind of ordinary cement, two kinds of medium heat cement, three kinds of crude steel cement, and four kinds of low heat cement; White cement (KS L 5204); And steel roughened cement; One or more selected from among them can be used.

When the amount of water used is less than 30 parts by weight of cement, the mortar may not be well stirred and mixed, and when used in excess of 60 parts by weight, the viscosity of the cement mortar may be too high, thereby delaying the curing of concrete.

The type of fine aggregate is not particularly limited, and the amount of the fine aggregate is preferably used in an amount of 100 to 300 parts by weight, more preferably 150 to 250 parts by weight, based on 100 parts by weight of the cement. At this time, if the amount of the fine aggregate is less than 100 parts by weight, there may be a problem that the strength is lowered, and if it exceeds 300 parts by weight, there may be an uneconomic problem, it is recommended to use within the above range.

The type of coarse aggregate is also not particularly limited, but it is preferable to use crushed aggregate, and the amount of coarse aggregate is 150 to 400 parts by weight, more preferably 150 to 300 parts by weight based on 100 parts by weight of cement. good. At this time, if the amount of coarse aggregate is less than 150 parts by weight, there may be a problem that the economic efficiency is lowered, it may be more than 400 parts by weight and there may be a problem that the material separation appears in the above range.

The admixture is used to obtain a water-reducing effect and workability-improving effect, and is not particularly limited, but it is preferable to use at least one selected from AE agents, AE water reducing agents, foaming agents, and fluidizing agents. And the usage-amount of 0.1-5 weight part with respect to 100 weight part of cement, It is good to use 0.5-2 weight part more preferably. In this case, when the amount of the admixture is less than 0.1 parts by weight, there may be a problem that the workability is lowered, and there may be a problem that the material is separated by more than 5 parts by weight, and it is preferable to use within the above range.

Referring to the manufacturing method of the fiber-reinforced concrete of the present invention having the composition as described above, the step of mixing the cement, fine aggregate, coarse aggregate, admixture and sheep fiber to dry the beam to produce a mixture; It comprises; adding water to the mixture, stirring and mixing.

And, in the step of preparing the mixture, the amount and type of each of the mixture is the same as described above, the mixture may be prepared by further mixing jute fibers.

Here, the dry beam is preferably performed for 30 seconds to 2 minutes, preferably 50 seconds to 70 seconds, the mixing step is 2 minutes to 5 minutes, preferably 2 minutes and 30 seconds after adding water It is good to stir 4 minutes and mix the said mixture with water.

The fiber-reinforced concrete of the present invention manufactured by the above method is a slump value measured by the KS F 2402 regulation in the state of not hardened, satisfies the following Equation 1, the air volume after the change over time (30 minutes) is 4 ~ 5%.

Equation 1

Initial slump value (mm) -15 mm≤ Slump value (mm) ≤ Initial slump value (mm) +15 mm

In Equation 1, the slump value is a slump measurement value measured 30 minutes after the production of the unconsolidated concrete.

When the fiber reinforced concrete of the present invention is cured, the compressive strength measured according to KS F 2405 is 30 to 40 MPa, and the tensile strength measured according to KS F 2423 is 3.00 to 4.00 MPa. In addition, the flexural strength measured according to KS F 2408 is 4.5 to 6 MPa, and the dry shrinkage length change rate measured according to KS F 2424 is -400 × 10 ^-6 to -550 × 10 ^-6 (based on 49 days of age). It has a very good physical properties.

[ Example ]

Example  One : Yam fiber  Preparation of Fiber Reinforced Concrete

Cement, fine aggregate, and coarse aggregate were added to the biaxial mixer, and then sprinkled evenly with the yarn fibers cut to 1 cm to 0.6 kg per m3 of fiber-reinforced concrete (0.6 kg / ㎥). Then, water was added to the mixture, and the fiber was reinforced after being discharged for 180 seconds to prepare fiber reinforced concrete. The amount of the component of the fiber reinforced concrete used in the preparation is shown in Table 1 below.

Unit (kg) cement water Fine aggregate Coarse aggregate Admixture 40.1 17.2 84.1 90.7 0.28
Cement: Type 1 ordinary Portland cement
Fine Aggregate: Assembly Rate 2.8, Cleaner of Samhan River
Coarse aggregate: crushed aggregate less than 13㎜
Admixture 1: AE Reducing Agent of Southeast Companies

Example  2 to 4

In the same manner as in Example 1 to prepare a fiber-reinforced concrete, Examples 2 to 4 were carried out using 0.9 kg / m 3, 1.2 kg / m 3 and 3 kg / m 3 of the hemp fibers, respectively.

Comparative example  1 to Comparative example  10

In the same manner as in Example 1 to prepare the fiber reinforcement concrete, but not using the sheep fiber, when the amount of the sheep wool fiber produced in excess of 3 kg / ㎥, with a sheep fiber cut to an average length of 2.2 cm Comparative Example 1 to Comparative Example 10 were carried out as shown in Table 2 using the other fibers instead of the case of the preparation and sheep fiber.

In particular, the macrosynthetic fibers of Comparative Examples 8 to 9 are fibers that are currently used as a steel fiber and wire mesh replacement agent in Europe, and a standard amount of 5 to 8 kg / m ³ is used.

division fiber
Kinds fiber
Mixing
(kg / m ³ ) Comparative Example 1 Use X none Comparative Example 2 1 cm shepherd fiber 3.5 Comparative Example 3 2.2 cm hemp fiber 0.9 Comparative Example 4 1 cm Jute Fiber 0.9 Comparative Example 5 Polypropylene fiber 0.9 Comparative Example 6 Pulp fiber 1.2 Comparative Example 7 Wood fiber 1.2 Comparative Example 8 Nylon fiber 0.6 Comparative Example 9 Macro Synthetic Fiber 5 Comparative Example 10 8 Jute Fiber: Contech's jute fiber cut into 1 cm
Polypropylene fiber: A brand name of Nikon material: Power mesh fiber
Pulp Fiber: Deokchang Construction Co., Ltd.
Wood fiber: Product name: Chemius Korea
Nylon fiber: SOS Co., Ltd.
Macrosynthetic fiber: Deokchang Construction

Experimental Example  1: slump measurement test of unconsolidated concrete

The change in the slump value of the concrete not hardened using the fiber reinforced concrete prepared in Examples 1 to 4 and Comparative Examples 1 to 10 was measured according to KS F 2402, and the results are shown in Table 3 below. If the measured slump value is the initial slump value ± 15 mm, the target value is considered to be satisfied.

division Type of fiber Early slump
(mm) After change over time (30 minutes)
Slump (mm) Slump change difference (mm) Example 1 Yam fiber 175 165 10 Example 2 Yam fiber 170 160 10 Example 3 Yam fiber 165 160 5 Example 4 Yam fiber 165 155 10 Comparative Example 1 - 180 165 15 Comparative Example 2 Yam fiber 174 160 14 Comparative Example 3 Yam fiber 170 157 13 Comparative Example 4 Jute fiber 165 150 15 Comparative Example 5 Polypropylene
fiber 160 140 20 Comparative Example 6 Pulp fiber 155 130 25 Comparative Example 7 Wood fiber 160 140 20 Comparative Example 8 Nylon fiber 155 140 15 Comparative Example 9 Macro
Synthetic fiber 160 150 10 Comparative Example 10 165 155 10

Looking at the slump value measurement results of Table 3, in the case of Comparative Example 3 using the fleece fiber having an average length of 2.2 cm, a fiber lumping phenomenon occurs that the slump variation difference is greater than the fleece fiber Examples 1 to 4 having an average length of 1 cm You can check it.

In Comparative Examples 5 to 7, the slump change values were 20 mm, 25 mm, and 20 mm, respectively, and the target values were not satisfied. Through this, in the case of fiber-reinforced concrete using polypropylene fiber, pulp fiber, or wood fiber, it was confirmed that a problem of deterioration of workability may occur due to a severe slump change.

Experimental Example  2: Air volume measurement test of unconsolidated concrete

The change in the slump value of the concrete which was not hardened using the fiber reinforced concrete prepared in Examples 1 to 4 and Comparative Examples 1 to 10 was measured according to KS F 2421. The results are shown in Table 4 below.

division Type of fiber Air volume (%) After change over time (30 minutes)
Air volume (%) Example 1 Yam fiber 5.1 4.9 Example 2 Yam fiber 5.3 4.3 Example 3 Yam fiber 5.7 4.1 Example 4 Yam fiber 5.9 4.2 Comparative Example 1 - 5.2 4.7 Comparative Example 2 Yam fiber 5.1 4.7 Comparative Example 3 Yam fiber 5.2 4.5 Comparative Example 4 Jute fiber 5.0 4.3 Comparative Example 5 Polypropylene
fiber 5.1 3.9 Comparative Example 6 Pulp fiber 5.1 4.0 Comparative Example 7 Wood fiber 5.2 4.3 Comparative Example 8 Nylon fiber 4.9 3.7 Comparative Example 9 Macro
Synthetic fiber 4.8 4.4 Comparative Example 10 5.0 4.6

As a result of the measurement results of the air volume measurement of Table 4, as the amount of fiber incorporation increased, it was found that the amount of air increased slightly in all fibers or equivalent to Comparative Example 1, in which no fibers were added. It is analyzed that this is due to the fact that there is no big difference according to the amount of incorporation.

Experimental Example 3 Experiment for Measuring Compressive Strength of Hardened Concrete

The compressive strength of the concrete cured using the fiber-reinforced concrete prepared in Examples 1 to 4 and Comparative Examples 1 to 10 was measured according to KS F 2405, and the results are shown in Table 5 below. And the measurement experiment photograph is shown to A of FIG.

division Type of fiber 7 days of age (MPa) 28 days of age (MPa) Example 1 Yam fiber 27.0 32.3 Example 2 Yam fiber 29.2 34.5 Example 3 Yam fiber 28.9 35.4 Example 4 Yam fiber 29.1 35.9 Comparative Example 1 - 26.0 29.5 Comparative Example 2 Yam fiber 26.1 29.7 Comparative Example 3 Yam fiber 26.2 29.8 Comparative Example 4 Jute fiber 27.2 31.6 Comparative Example 5 Polypropylene
fiber 22.7 31.0 Comparative Example 6 Pulp fiber 26.8 27.6 Comparative Example 7 Wood fiber 25.5 26.9 Comparative Example 8 Nylon fiber 26.5 30.5 Comparative Example 9 Macro
Synthetic fiber 23.7 28.4 Comparative Example 10 22.6 27.1

Looking at the results of measuring the compressive strength of Table 5, in Comparative Example 1 to Comparative Example 3, Comparative Example 6 to Comparative Example 7 and Comparative Example 9 to Comparative Example 10, the compressive strength measured after 28 days elapsed less than 30 MPa You can see that it is not good. Through this, it can be confirmed that in the case of pulp fibers, wood fibers and macro synthetic fibers, which are recently used as steel and wire mesh substitutes in Europe, concrete having satisfactory compressive strength cannot be produced. In addition, even if the use of hemp fiber was used in excess of 3.0 kg / m ³ , or if the average length exceeds 2 cm, it could be confirmed that the compressive strength is not good.

However, in Examples 1 to 4, which are concrete of the present invention, it was confirmed that the fibers having a higher compressive strength than other concretes, in particular, jute fibers or concrete using polypropylene fibers, which was compared with the cement paste It is believed that the strength of the concrete structure is increased due to the excellent adhesion performance.

Experimental Example 4 Experiment for Measuring Tensile Strength of Hardened Concrete

The tensile strength of the concrete cured using the fiber reinforced concrete prepared in Examples 1 to 4 and Comparative Examples 1 to 10 was measured according to KS F 2423, and the results are shown in Table 6 below. An experimental photograph is shown in B of FIG. 5.

division Type of fiber 7 days of age (MPa) 28 days of age (MPa) Example 1 Yam fiber 2.13 3.05 Example 2 Yam fiber 2.23 3.14 Example 3 Yam fiber 2.35 3.15 Example 4 Yam fiber 2.41 3.21 Comparative Example 1 - 1.85 2.59 Comparative Example 2 Yam fiber 1.92 2.61 Comparative Example 3 Yam fiber 1.95 2.65 Comparative Example 4 Jute fiber 2.20 3.02 Comparative Example 5 Polypropylene
fiber 2.34 2.72 Comparative Example 6 Pulp fiber 2.00 2.44 Comparative Example 7 Wood fiber 1.89 2.31 Comparative Example 8 Nylon fiber 2.29 2.66 Comparative Example 9 Macro
Synthetic fiber 2.01 2.34 Comparative Example 10 2.14 2.46

Looking at the tensile strength measurement results of Table 6, the tensile strength measured on the 28th day of age except for Examples 1 to 4 and Comparative Example 4 was not good less than 3.00 MPa, concrete containing jute fibers and hemp fibers Tensile strength of was significantly increased 28 days tensile strength compared to 7 days tensile strength. Through this, it was confirmed that the tensile strength of the concrete using the jute fiber or hemp fiber is superior to the concrete using the chemical fiber or synthetic fiber. In addition, in Comparative Example 2 using more than 3.0 kg / m ³ of the hemp fiber and Comparative Example 3 using a sheep fiber having an average length of 2.2 cm, the tensile strength was lower than in Example, through which the present invention suggests In the case of the concrete using the hemp fiber more than the average length, it could be confirmed that the sufficient increase in tensile strength.

Experimental Example  5: Flexural strength measurement experiment of hardened concrete

The flexural strength of the concrete cured using the fiber-reinforced concrete prepared in Examples 1 to 4 and Comparative Examples 1 to 10 was measured according to KS F 2408, and the results are shown in Table 7 below. The photo is shown in Fig. 5C.

division Type of fiber 7 days (MPa) 28 days (MPa) Example 1 Yam fiber 3.9 4.7 Example 2 Yam fiber 4.0 4.96 Example 3 Yam fiber 4.2 5.11 Example 4 Yam fiber 4.24 5.27 Comparative Example 1 - 3.78 4.60 Comparative Example 2 Yam fiber 3.82 4.62 Comparative Example 3 Yam fiber 3.85 4.65 Comparative Example 4 Jute fiber 4.1 4.7 Comparative Example 5 Polypropylene
fiber 4.23 4.85 Comparative Example 6 Pulp fiber 3.95 4.55 Comparative Example 7 Wood fiber 4.07 4.46 Comparative Example 8 Nylon fiber 4.05 4.54 Comparative Example 9 Macro
Synthetic fiber 3.80 4.35 Comparative Example 10 3.89 4.54

Looking at the bending strength measurement results of Table 7, it can be confirmed that only the concrete of Examples 1 to 4 and Comparative Examples 4 to 5 is superior to the bending strength measured on the 28th day than Comparative Example 1 without using the fiber. In addition, although Comparative Example 2 and Comparative Example 3 used hemp fiber, overall bending strength was not better than that of Example. And comparing Example 2 and Comparative Example 3 using the same amount of hemp fibers and jute fibers, it was confirmed that the concrete of Example 2 has a very good flexural strength than Comparative Example 4.

Experimental Example  6: dry shrinkage length change rate measurement experiment

Using the fiber-reinforced concrete prepared in Examples 1 to 4 and Comparative Examples 1 to 10, the dry shrinkage length was measured according to KS F 2424. The results are shown in Tables 8 and 9 below.

Change rate of drying shrinkage unit (× 10 ^-6 ) Age
(Work) Example One 2 3 4 0 0 0 0 0 2 -11.2 -10.4 -8.8 -8.5 4 -76.7 -68.9 -56.7 -51.2 6 -121.1 -103 -98.4 -94.7 7 -165.4 -154.4 -121.3 -109.8 14 -194.5 -189.5 -156.5 -124.7 21 -252.3 -239.4 -212.3 -198.9 28 -331.2 -300.1 -298.5 -291.3 35 -401.2 -389.9 -365.6 -347.0 42 -434.5 -425.6 -434.5 -411.2 49 -487.9 -501.2 -467.8 -442.9 56 -562.3 -531.2 -508.1 -484.5

Change rate of drying shrinkage unit (× 10 ^-6 ) Age
(Work) Comparative example One 2 3 4 5 6 7 8 9 10 0 0 0 0 0 0 0 0 0 0 0 2 -26.3 -17.4 -18.5 -13.2 -23.1 -39.5 -13.2 -26.3 -24.2 -39.5 4 -78.9 -74.6 -79.4 -118.4 -88.4 -92.1 -78.9 -157.9 -39.5 -157.9 6 -118.4 -120.2 -120.7 -184.2 -145.6 -157.9 -157.9 -289.5 -105.3 -263.2 7 -184.2 -159.1 -160.3 -250 -198.4 -236.8 -223.7 -328.9 -144.7 -289.5 14 -250 -214.8 -218.1 -315.8 -289.3 -342.1 -289.5 -355.3 -197.4 -342.1 21 -342.1 -259.3 -261.8 -381.6 -332.1 -381.6 -368.4 -394.7 -276.3 -381.6 28 -434.2 -361.9 -367.5 -434.2 -415.1 -447.4 -407.9 -447.4 -381.6 -421.1 35 -500 -453.1 -452.3 -473.7 -489.9 -500 -473.7 -500 -421.1 -473.7 42 -526.3 -493.6 -495.9 -513.2 -537.6 -539.5 -513.2 -539.5 -513.2 -539.5 49 -578.9 -529.5 -531.8 -578.9 -588.9 -565.8 -526.3 -552.6 -539.5 -592.1 56 -592.1 -552.4 -557.3 -580.1 -602.1 -578.9 -526.3 -552.6 -552.6 -605.2

Looking at the measurement results of the dry shrinkage length change rate of Table 8 and Table 9, the dry shrinkage length change rate showed a sharp shrinkage at the early age, and generally showed a tendency after a sudden shrinkage until about 50 days. And, in all concrete except the concrete of Examples 1 to 4 of the present invention showed a similar shrinkage to the concrete of Comparative Example 1. In addition, as the amount of incorporation of hemp fibers increased, the shrinkage tended to decrease, but the difference was not large.

Through the above experimental example, it was confirmed that the concrete using the hemp fiber had better overall mechanical properties than the conventional synthetic fiber and the jute fiber, and also in the case of using the amount and average length of the hemp fiber proposed by the present invention. It was confirmed that concrete with excellent physical properties could not be produced. By providing a new concrete through the fiber reinforced concrete of the present invention, it is expected that more environmentally friendly building, construction and the like.

Claims (10)

30 to 60 parts by weight of water, 100 to 300 parts by weight of fine aggregate, based on 100 parts by weight of cement,
It contains 0.3 to 3 kg of hemp fiber per 1m3 of cement mixture containing 150 to 400 parts by weight of coarse aggregate and 0.1 to 5 parts by weight of admixture. Eco-friendly fiber reinforced concrete, characterized in that the slump value measured by the regulations satisfy the following equation 1;
Equation 1
Initial slump value (mm) -15 mm≤ Slump value (mm) ≤ Initial slump value (mm) +15 mm
In Equation 1, the slump value is 30 minutes after producing the non-solid concrete
It is the slump measurement value measured after the passage.











delete delete delete delete delete The eco-friendly fiber reinforced concrete according to claim 1, wherein the compressive strength measured according to KS F 2405 is 30 to 40 MPa.
The eco-friendly fiber reinforced concrete according to claim 1, wherein the tensile strength measured according to KS F 2423 is 3.00 to 4.00 MPa.
The environmentally friendly fiber-reinforced concrete according to claim 1, wherein the flexural strength measured according to KS F 2408 is 4.5 to 6 MPa.
The eco-friendly fiber reinforced concrete according to claim 1, wherein the dry shrinkage length change rate measured according to KS F 2424 is -400 × 10 ^-6 to -550 × 10 ^-6 (based on 49 days of age).

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