KR101065037B1 - Latex modified concrete composition comprising fibrous reinforcement - Google Patents

Abstract

The present invention relates to a latex modified concrete composition comprising cement, latex, and aggregate, and more particularly, to a latex modified concrete composition further comprising a fiber reinforcement in an amount of 0.5 to 1.5 parts by weight based on 100 parts by weight of cement.

According to the present invention, it is possible to prevent cracks generated in the latex modified concrete (LMC) paving section of the bridge, to improve the flexural toughness, to prevent the detachment of concrete during partial breakage of the LMC pavement, and to progress the deterioration of the package by direct sunlight. It is possible to construct a multifunctional cross-linked package that suppresses and improves the sharpness of the lane.

Latex modified concrete, fiber reinforcement, flexural toughness, carbon black

Description

LATEX MODIFIED CONCRETE COMPOSITION COMPRISING COMPRISING FIBROUS REINFORCEMENT}

The present invention relates to latex modified concrete compositions comprising cement, latex, aggregate, and fiber reinforcement.

In general, the latex modified concrete (LMC) method refers to a pavement material which improves the performance of concrete by adding latex to a general concrete composition.

This LMC method is a method of increasing the use area of the waterproof bridge and the adhesion in the construction of the bridge pavement construction is currently being widely used as the optimal bridge pavement method in consideration of the life cycle cost of the structure (Life Cycle Cost). Currently, the LMC method is more frequently used for repairing defects in the occurrence of deterioration of bridge pavement and bridge pavement of new highway bridges because of excellent waterproofness, durability, and maintainability compared to other bridge pavement methods.

Conventionally, ascon paving method and concrete paving method are commonly used as a method of repairing a bridge structure. Ascon packing method needs to be repacked periodically to secure necessary driving due to plastic deformation, deterioration, etc., resulting in over-injection of maintenance costs and traffic obstacles, and it is difficult to identify signs of aging on bridge decks. In addition, when the construction of the waterproof layer is poor, chloride penetrates into the upper plate to corrode the steel or deteriorate concrete, thereby shortening the commonness of the bridge.

On the other hand, according to the concrete pavement method, it is excellent in workability by simultaneous pouring with the floor slab concrete of the bridge, but it is difficult to secure the flatness required. There is a disadvantage that the degradation of the bridge occurs.

Bridges are usually about four years in life, so repacking every four years involves maintenance and traffic problems. In addition, the bridge pavement has to serve as a roof to protect the bridge, so it is necessary to prevent leakage and improve the life of the mold. Currently, the bridge construction method in Korea requires waterproofing construction between pavement and floor concrete surface, which leads to an increase in construction cost. Ascon pavement, which has been commonly applied, has low strength and low density of material properties. Therefore, when repeatedly subjected to repeated heavy load due to illegal heavy vehicle or traffic increase, plastic deformation, debonding, spalling, shoving, etc. occur in the pavement pavement, causing asphalt to fall off from concrete, which is a pavement material. Rainwater, air, and chloride ions penetrate through the cracks, deteriorating the concrete deck and causing corrosion of the reinforcing bars, resulting in radical aging of the bridge, which ultimately degrades the durability of the bridge.

In order to improve the disadvantages of the existing concrete pavement method, LMC method of adding a latex to the concrete composition is widely used as the optimal cross-section paving method.

However, as the usability of the LMC method is increased, it is difficult to secure quality due to insufficient construction management and poor maintenance. In particular, LMC is excellent in bonding strength between internal particles of concrete (Con'c) by latex particles, but the installation thickness is at least 3.5 ~ 5 cm. There is a risk that a piece of concrete may hit the driving vehicle and cause a safety accident of the driving vehicle.

Therefore, it is necessary to study the development of latex modified concrete that can minimize the occurrence of cracks and prevent the falling of concrete fragments even if cracks occur.

The present invention is to provide a latex modified concrete composition that can increase the cracking inhibiting power of the existing LMC method and prevent partial breakage during cracking.

The present invention provides a latex modified concrete composition further comprising a fiber reinforcement in an amount of 0.5 to 1.5 parts by weight based on 100 parts by weight of cement in the latex modified concrete composition comprising cement, latex, and aggregate.

The present invention also provides a latex modified concrete prepared using the composition, having a slump of 160 to 220 mm and an air volume of 3% to 6%.

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

The present invention is to mix the latex (Latex) in the concrete, at the same time, by mixing the fiber reinforcement material in the optimum range to increase the cracking suppression force of the existing LMC method and to prevent partial breakage when the crack occurs, the latex (the main raw material of the concrete performance improving material) It is to provide an economical latex modified concrete (LMC) composition according to the material cost reduction by reducing the amount of latex (M).

In particular, in the case of latex modified concrete (LMC) in which latex is added to cement concrete as in the present invention, the latex particles act independently during concrete placing, thereby increasing the fluidity of the concrete, and a hydration reaction. In the process, a latex particle film is formed around the cement hydrate to increase adhesion, and after curing, the micropores in the concrete are filled by the latex solids to suppress the occurrence of cracking.

In general, when the cement concrete is dried, the cement hydrate shrinks to cause microcracks in the cement hydrate, and the propagation of the microcracks causes the concrete to lose its tensile strength and increase the penetration of chlorides or harmful chemicals. , The present invention is because the effect of the latex and fiber reinforcement effective reinforcing effect is filled with microcrack pores in the cement hydrate, and the propagation of microcrack is suppressed, the effect that the tensile strength, flexural strength, flexural tensile strength, etc. of concrete is increased. Can be obtained.

The latex modified concrete composition of the present invention is characterized in that it further comprises a fiber reinforcement in an amount of 0.5 to 1.5 parts by weight with respect to 100 parts by weight of cement.

It is preferable to use Portland cement as the cement, but in addition to this, all kinds of commercially available cements may be used.

In addition, the fiber reinforcing material may be at least one selected from the group consisting of polyamide fiber, polyethylene fiber, polyacrylic fiber, polyester fiber, polypropylene fiber, polyvinyl alcohol fiber, cellulose fiber and the like. Among them, it is preferable to use polyamide fibers in terms of high affinity with all the components to obtain uniform dispersibility without fiber-ball and impart excellent physical properties such as strength. Examples of the polyamide fiber reinforcement include polyamide (nylon) 6, polyamide (nylon) 66, aramid, and the like, and more preferably nylon 6 may be used. In general, polyamide fiber is a relatively good inert material, and has excellent resistance to various organic and inorganic materials including strong bases, so that it can be effectively used as a fiber reinforcement in the latex modified concrete composition of the present invention.

In addition, the fiber reinforcement may be used in a variety of forms, for example, using a standard (Crimp) type and (Crimp) type, or may be used in a variety of cross-sectional shapes, such as triangular, square, round. For example, the length of the fiber reinforcement may be 1 to 100 mm, preferably 6 to 40 mm, the diameter of the cross section of the fiber reinforcement or may be 10 to 70 ㎛, preferably 20 to 40 ㎛. The length and diameter or thickness of the fiber reinforcement can be adjusted to the optimum range according to the quality of the concrete, durable performance and compressive strength, bending strength and toughness.

In a preferred example, the fiber reinforcement may be used in a single length and a single diameter to maintain a single shape. In this case, the single shape in the fiber reinforcement means that different fibers of any length or diameter are not mixed, and a fiber reinforcement having a single shape having a single length and a single diameter in terms of dispersibility in concrete is used. It is desirable to.

In addition, the fiber reinforcement has a strength measured by a gauge length of 5 mm (7.5 mm) or more, preferably 9.5 g / d or more, and an elongation measured by a gauge length (5 mm). It may be 50% to 120%, preferably 70 to 110%. In the present invention, when the strength and elongation of the fiber reinforcing material is out of the above range, the effect of improving the bending strength of the concrete, etc. may be insignificant.

The fiber reinforcement may have a relative viscosity (RV) of 2.9 or more, or 2.9 to 5.0, preferably 3.2 or more, or 3.2 to 4.5, and the relative viscosity (RV) of the fiber reinforcement is lower than the above range. If the fiber itself, the strength and wear resistance of the fiber may be lowered.

In the present invention, the fiber reinforcing material may be used having a fineness of 1 to 10 denier, preferably 1.5 to 5 denier. When the fineness is less than 1 denier, there is an advantage that the surface area of the fiber is increased to increase the contact area with the concrete, but the strength of the fiber itself may be lowered and the dispersibility of the fiber in the concrete may be reduced. On the other hand, when the fineness exceeds 10 denier, the number of fibers per unit area of concrete decreases, which may cause a risk of forming a relatively weak portion in concrete.

In addition, the polyamide fiber reinforcing material may be coated with a coating liquid containing an ester-based lubricant and a nonionic surfactant on the fiber surface, through this coating can be greatly improved dispersibility in the concrete and bonding strength with the concrete. Considering the effect of improving the dispersibility and bonding strength of the fiber reinforcement, the coating amount of the coating liquid is preferably 0.5 to 3% by weight based on the total weight of the polyamide fiber. However, in the present invention, the coating amount of the coating solution is not particularly limited, and as a preferred example, the coating solution is 40 to 50 wt% of a polyhydric alcohol ester lubricant, 30 to 40 wt% of nonionic surfactant, and 10 to 10 antistatic agents. It may be used consisting of 30% by weight.

The fiber reinforcing material may be included in an amount of 0.5 to 1.5 parts by weight, preferably 0.7 to 1.3 parts by weight, and more preferably 0.9 to 1.2 parts by weight, based on 100 parts by weight of cement. When the content of the fiber reinforcing material is less than 0.5 parts by weight with respect to 100 parts by weight of cement, it is difficult to obtain an excellent effect difference in structural aspects such as cracking inhibition and LMC particles. When the content of the fiber reinforcing material exceeds 1.5 parts by weight based on 100 parts by weight of cement, the fiber reinforcing material is not uniformly dispersed, and the slump is reduced, so that the workability of the site due to the deterioration of workability may be partially deteriorated.

In addition, the fiber reinforcement is 2.0 to 6.0 kg / m ³ , preferably 3.5 to 4.5 kg / m ³ , more preferably 3.7 to 4.3 kg / m ³ , more preferably 3.9 to 4.1 kg relative to the concrete unit volume / m ³ can be included. It is preferable to maintain the content in the above range in terms of workability and bending strength, compressive strength, durability, wear resistance and the like.

In the present invention, by inserting the fiber reinforcing material in such an optimum range, it is possible to significantly improve the compressive strength, flexural strength and flexural toughness by uniformly dispersed in the concrete. In particular, the fiber reinforcement material can suppress the occurrence of cracks as much as possible and prevent the falling off of the concrete fragments, even if the crack occurs, increase the ductility of the concrete and at the same time reduce the amount of latex can be improved economic efficiency.

On the other hand, in the latex modified concrete composition of the present invention, latex (Latex) generally refers to a natural product obtained from a rubber tree, but most of the latex commercially available styrene (Styrene) and butadiene (Butadiene) is composed of the main monomer A milky liquid substance made by mixing a polymer copolymerized with water and water at a certain ratio, and the polymer occupies about 45% to 47%, and the main component of the polymer is styrene / butadiene in a constant ratio and a small amount. It is a material to which surfactant and stabilizer are added, and small spherical organic polymer particles such as colloid (about 0.5 to 5 µm in diameter) are dispersed in water.

The particles may be coated with a surfactant and remain suspended in water. In the present invention, the unit quantity was calculated based on 47%.

In the present invention, the latex may be included in 10 to 32 parts by weight, preferably 14 to 25 parts by weight, more preferably 19 to 21 parts by weight with respect to 100 parts by weight of cement. If the content of the latex is less than 10 parts by weight, it is difficult to secure sufficient structural properties such as sufficient field workability and required strength, watertightness, and durability. If the content of the latex is more than 32 parts by weight, the latex particle film formed around the aggregate causes the compressive fracture surface. Rather, the compressive strength is reduced because of the formation, which is uneconomically undesirable due to excessive construction costs.

In addition, the latex may be included as 40 to 128 kg / m ³ , preferably 56 to 100 kg / m ³ , more preferably 76 to 84 kg / m ³ with respect to the concrete unit volume. It is desirable to maintain the content in the above range in terms of field workability and required strength, watertightness, durability.

In a preferred embodiment, the fiber reinforcement and latex may be included in a content ratio of 1:10 to 1:35, preferably 1:14 to 1:25, more preferably 1:19 to 1:21 by weight. have. When the content ratio of the fiber reinforcing material and latex exceeds 1:35, the fiber reinforcing material per unit volume is relatively insufficient, and thus, the cracking inhibiting force may not be sufficient due to the fiber reinforcing material, and the structural effect such as bonding strength between the LMC particles may be obtained. In particular, the fiber reinforcement content may not be sufficient, so it may be difficult to obtain the economic efficiency improvement effect due to the improved ductility of the concrete and the amount of latex incorporation. In addition, when the content ratio of the fiber reinforcement and latex is less than 1:10, the fiber reinforcement per unit volume is included in relatively large amount, so that the dispersibility of the concrete is reduced and the slump is reduced, which may not be good in the field workability due to reduced workability. Strength or watertightness may be lowered. Therefore, it is preferable to maintain the content ratio in the above range in order to obtain a sufficient synergistic effect of the concrete according to the mixing of the fiber reinforcement and latex.

The latex modified concrete composition of the present invention may include water in the amount of 322 to 285 parts by weight, preferably 312 to 294 parts by weight based on 100 parts by weight of cement. In the present invention, the water may be included in 1,290 to 1,143 kg / m ³ , preferably 1,250 to 1,176 kg / m ³ with respect to the concrete unit volume. Here, the water content can be adjusted to the optimum range in terms of strength and fluidity of the concrete.

Aggregate in the present invention can be used generally known as concrete, can be used as fine aggregate and coarse aggregate. As the fine aggregate, those having a maximum dimension of 0.15 to 4.5 mm, an absolute dry density of 2.5 g / cm ³ or more, an absorption rate of 3% or less, and a stability of 10% or less can be used as the fine aggregate. As the coarse aggregate, those having a particle size of 4.6 to 40 mm, an absolute dry density of 2.5 g / cm ³ or more, an absorption rate of 3% or less, a stability of 10% or less, and a wear rate of 40% or less may be used as the coarse aggregate.

The latex modified concrete composition of the present invention may be included in the coarse aggregate 177 to 182 parts by weight, preferably 178 to 181 parts by weight based on 100 parts by weight of cement. In addition, the coarse aggregate in the present invention may be included as 710 to 730 kg / m ³ , preferably 715 to 725 kg / m ³ with respect to the concrete unit volume. The coarse aggregate is preferably used in the content range in terms of fluidity and material separation reduction.

The fine aggregate may be included as 235 to 240 parts by weight, preferably 236 to 238 parts by weight based on 100 parts by weight of cement. In addition, the fine aggregate in the present invention may be included as 940 to 960 kg / m ³ , preferably 945 to 955 kg / m ³ with respect to the concrete unit volume. Here, it is preferable to include fine aggregate in the above range in terms of fluidity and material separation reduction.

The present invention may further include a blast furnace slag fine powder for improving the durability and resistance to alkali aggregate reaction together with the aggregate, wherein the blast furnace slag fine powder is granulated by quenching the slag discharged from the furnace Crushed, can be used without particular limitation within the range known to be generally available for concrete mixing.

In a preferred embodiment of the present invention, the latex modified concrete composition is based on 100 parts by weight of cement, 95 to 105 parts by weight of cement, 322 to 285 parts by weight of water, coarse aggregates 177 to 182 parts by weight, fine aggregates 235 to 240 parts by weight , 10 to 32 parts by weight of latex, and 0.5 to 1.5 parts by weight of fiber reinforcement.

In another preferred embodiment of the present invention, the latex modified concrete composition is based on the concrete unit volume of cement 380 to 420 kg / m ³ , water 1,290 to 1,143 kg / m ³ , coarse aggregate 710 to 730 kg / m ³ , Fine aggregate 940 to 960 kg / m ³ , latex 40 to 128 kg / m ³ , and the fiber reinforcement may include 2.0 to 6.0 kg / m ³ .

In addition, the latex modified concrete composition of the present invention by mixing carbon black (Carbon black) resistant to ultraviolet rays in addition to the fiber reinforced LMC, thereby suppressing the progress of the degradation of the package due to direct sunlight of the LMC package, the glare phenomenon It is possible to improve the driver's lane identification by reducing and improving the sharpness of lanes in rainy weather.

The carbon black may be included in an amount of 0.5 to 1.5, preferably 0.75 to 1.25 parts by weight based on 100 parts by weight of cement. In addition, the carbon black in the present invention may be included in 2 to 6 kg / m ³ , preferably 3 to 5 kg / m ³ with respect to the concrete volume. At this time, when the content of the carbon black is less than the lower limit in the above range, it is difficult to obtain sufficient UV resistance and coloring effect of the desired degree when applied to the road. On the other hand, when the upper limit is exceeded in the above range, the compressive strength and the bending strength are remarkably poor, which is not preferable.

On the other hand, the latex modified concrete composition of the present invention is a step of mixing the cement, aggregate, and latex-added water and then thoroughly rubbing, and 0.5 parts by weight to 1.5 parts by weight of the fiber reinforcement in the mixer with respect to 100 parts by weight of cement The method may be prepared by additionally adding the mixture in the amount of parts and mixing the same to perform the rubbing again for about 1.5 minutes.

The present invention also provides a latex modified concrete prepared using the composition, having a slump of 160 to 220 mm, preferably 170 to 190 mm, and an air content of 3% to 6%, preferably 4% to 5%. to provide.

The latex modified concrete according to the present invention was designed based on the bending strength and the wear loss of the existing LMC package, and the flexural strength is 4.5 Mpa or more, the wear loss is 14% or less, and the compressive strength is designed based on the 27 Mpa or more when designing the package. The structural determination method may be 5 to 6 N / mm ² , preferably 5.3 to 5.8 N / mm ² at 28 days (f28) measured according to the KS F2408 method. The abrasion loss measured by using can be 12% to 14%, preferably 12.5% to 13.5% of the sample weight before measurement, and the compressive strength of 36 days of age (f28) measured according to the KS F2405 method is 36 To 38 N / mm ² , preferably 37.5 to 38.5 N / mm ² .

In addition, the latex-modified concrete of the present invention does not cause cracks in the structure in the fracture test under a specific load, or even when the structure is cracked, there is no "brittle fracture" of the phenomenon that is immediately destroyed or both ends, and for a certain period until both ends are destroyed. Delayed phenomenon may result in "ductile failure", which is equivalent to delayed failure. Particularly, even if the loading speed is 0.2 Mpa / sec or more, even if the crack of the structure occurs within at least 30 seconds does not cause the complete destruction or bothover, more preferably the loading speed is 1.0 Mpa / sec or more Under at least 10 seconds even if the crack of the structure of the structure may not cause a complete destruction or both ends.

In such a fracture test, "brittle fracture" is not preferable because the pavement has a short maintenance time necessary for reinforcement when cracking occurs due to rapid pavement breakage when fatigue cracking occurs due to traffic load. In order to prevent such a situation, "soft rupture" is preferable in view of suppressing the progress of cracking until the package reaches full destruction even if the package cracks.

In particular, if the loading speed is brittle fracture within 10 seconds under 1.0 Mpa / sec load, the delayed fracture of the structure is not convinced can cause a lot of problems caused by brittle fracture.

In the present invention, matters other than those described above can be added or subtracted as required, and therefore, the present invention is not particularly limited thereto.

The present invention is further mixed with the fiber reinforcement material in the optimum range of the latex modified concrete composition, thereby improving the physical properties such as compressive strength, flexural toughness, wear loss, etc. from this suppresses the occurrence of cracks and increase the flexural strength, partial dropping when cracking occurs It is effective in prevention.

In addition, the present invention can further improve the durability of the LMC by the addition of carbon black (Carbon black) resistant to ultraviolet rays and change the concrete color to black to improve the clarity of the lane to ensure the safety of the driving vehicle.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the scope of the present invention is not limited to the following examples.

Example 1

With the composition as shown in Table 1, 1.0 parts by weight of fiber reinforcement was added to 285 parts by weight of cement and 179 parts by weight of coarse aggregate, 245 parts by weight of fine aggregate, and 10 parts by weight of latex based on 100 parts by weight of cement. A latex modified concrete composition was prepared by rubbing for about 1.5 minutes.

At this time, "Ordinary Portland Cement (OPC)" was used as cement, coarse aggregates used crushed gravel having a maximum dimension of 13 mm, and fine aggregates used by washing sea sand having a maximum dimension of 0.15 to 2.5 mm. It was. The fine aggregate used was made of a density of 2.5 g / cm ³ or more, coarse aggregate was used according to KS F 2526 "concrete aggregates" made of a density of 2.5 g / cm ³ or more.

As a latex, a solid content of 47% by weight was used. As a fiber reinforcing material, a specific gravity of 1.16, a diameter of 23 μm, a length of 20 mm, a tensile strength of 919 MPa, an elastic modulus of 5.3 GPa, an elongation of 87%, and a melting point of 221 ° C. were used. Was used. At this time, the content ratio of the fiber reinforcing material and latex was 1:21.

In addition, the slump and water_cement ratio (W / c), the unit amount of the range as shown in Table 1, the compounding target, water, cement, fine aggregate, coarse aggregate, latex, fiber reinforcement and the like were mixed. At this time, the air content was 4.5 ± 1.5%, fine aggregate (S / A) 58%, the design bending strength was carried out concrete mixing with a targeting goal of 4.5 N / mm ² .

Examples 2-5 and Comparative Examples 1-5

As shown in Table 1, except that the composition, the compounding target value of each component, the fiber stiffener and the latex content ratio was different, the latex modified concrete composition was prepared in the same manner as in Example 1.

The main component content and composition of the concrete composition according to Examples 1 to 5 and Comparative Examples 1 to 5 are as shown in Table 1 below.

division slump
(mm) water-
cement
W / c
(%) fiber
reinforcement
content
(Parts by weight) fiber
reinforcement:
Latex content ratio Unit weight (㎏ / ㎡) water
W cement
C Fine aggregate
S thick
aggregate
G Latex
Latex fiber
reinforcement Carbon
black Example 1 190
± 30 35 1.0 1:21 95 400 982 717 85 4.0 - Example 2 190
± 30 35 1.0 1:21 95 400 982 717 85 4.0 4.0 Example 3 190
± 1.5 33 0.9 1:25 91 400 988 721 94 3.6 - Example 4 190
± 1.5 33 0.75 1:32 91 400 988 721 94 3.0 - Example 5 190
± 30 33 0.75 1:32 91 400 988 721 94 3.0 4.0 Comparative Example 1 190
± 30 33 - - 64 400 953 715 128 - - Comparative Example 2 190
± 30 35 - - 95 400 982 717 85 - - Comparative Example 3 190
± 1.5 33 0.225 1:84 82 400 988 721 94 0.9 - Comparative Example 4 190
± 1.5 33 0.225 1:40 91 400 1000 730 77 0.9 - Comparative Example 5 190
± 30 33 0.225 1: 142 64 400 965 704 128 0.9 4.0

The physical properties of the concrete compositions prepared according to Examples 1 to 5 and Comparative Examples 1 to 5 and the fiber-reinforced latex modified concrete specimens prepared therefrom were measured in the following manner.

slump

It was measured by the concrete slump contest according to the method of KS F2402.

Air volume

According to the KS F2449 method was measured by the volume of the concrete not hardened.

Compressive strength

According to the method of KS F2405, it was measured by the compression fracture method of concrete specimens (age 7 days, age 28 days).

Flexural strength

According to the KS F2408 method, it was measured by the method of three-point load (age 7 days, age 28 days).

Wear loss

According to the KS F 2508 method was measured by a method of Los Angeles wear tester. In this case, the test was performed by rotating the test specimens 4 and 12 steel balls (5 kg) 500 times in the case of using the iron ball, and the test was carried out by rotating the test specimens and 2.5 kg of sand 500 times when using sand. .

Fracture Test

According to KS F2408 method, it is called "brittle fracture" when it breaks or ends when a crack occurs in a structure within 10 seconds under a load speed of 1.0 Mpa / sec or more. Even when generated, it is referred to as "ductile fracture" when no fracture or phenomenon occurs for more than 10 seconds.

Measurement results of the physical properties of the concrete composition and concrete prepared according to Examples 1 to 5 and Comparative Examples 1 to 5 are as shown in Table 2 below.

division slump
(mm) Air volume
(%) Flexural strength
(N / mm2) Wear loss
(%) Compressive strength
(N / mm2) Fracture Test f7 f28 Iron ball sand f7 f28 Example 1 215 4.5 4.78 5.84 13.3 4.3 26.2 36.9 Duct failure Example 2 180 4.5 4.78 5.84 13.3 4.3 27.0 35.9 Duct failure Example 3 170 4.5 4.85 5.82 13.3 4.3 28.0 37.6 Duct failure Example 4 185 4.4 4.75 5.72 13.3 4.3 27.8 37.2 Duct failure Example 5 165 4.4 4.75 5.72 13.3 4.3 27.8 37.2 Duct failure Comparative Example 1 215 4.5 4.51 5.20 14.9 5.3 27.4 37.6 Brittle fracture Comparative Example 2 215 4.5 4.51 5.20 14.9 5.3 27.4 37.6 Brittle fracture Comparative Example 3 170 4.4 4.52 5.36 14.9 5.3 26.7 36.9 Brittle fracture Comparative Example 4 155 4.2 4.45 5.00 14.9 5.3 26.4 36.5 Brittle fracture Comparative Example 5 175 4.5 4.65 5.53 14.9 5.3 27.0 36.4 Brittle fracture

In addition, after the flexural strength test for the fiber-reinforced latex-modified concrete prepared according to Example 1 and the conventional latex-modified concrete prepared according to Comparative Example 1 are shown a photograph of the ductile fracture phenomenon of the specimens, respectively, Figure 1a and 1b It was. In addition, the photographs of the specimens before and after the wear loss test for the two concrete are shown in Figures 2a and 2b, respectively.

As a result of the fracture test, the specimens using the existing LMC show brittle fracture which is suddenly destroyed at the time of fracture, but the nylon fiber reinforced LMC shows the ductile fracture phenomenon that catches the crack by nylon fiber reinforcement even if it breaks. Even if the concrete is partially damaged, the fiber reinforcement is expected to play a role of preventing detachment.

In particular, general pavement is a normal pavement breakdown mechanism in which microcracks generated by repeated loads by public vehicles are gradually degraded due to fatigue load and deterioration and durability of pavement is gradually degraded. )to be. However, the fiber reinforcement used in the present invention prevents cracks from forming closely in the bonding force in concrete and prevents further progression even if cracks are generated. It can be seen that driving performance and maintenance cost can be reduced.

As shown in Table 2, the latex modified concrete composition of Examples 1 to 5 including the fiber reinforcement in the optimum range according to the present invention can ensure improved performance in terms of slump, air volume, compressive strength, bending strength, wear It can also be seen that the weight loss is also significantly reduced to have excellent durability. Particularly, in the case of Example 2, which further includes carbon black together with the fiber reinforcing material, it is possible to increase the resistance to ultraviolet rays and to increase the sharpness of the lanes, thereby having multi-function having superior performance in terms of economics and structure compared to conventional LMC. It can be seen that. On the other hand, it can be seen that Comparative Examples 1 and 2 are not preferable in terms of strength.

Furthermore, in the case of the fiber-reinforced latex modified concrete according to the present invention, although the latex content was significantly reduced to 10% compared to Comparative Example 1, which is a conventional LMC specification, it has better performance in compressive strength, bending strength, and wear loss. It was.

In particular, as can be seen from the results of the physical properties of Comparative Examples 1 and 2, it can be seen that generally reducing the latex content, thereby significantly reducing the bending strength. However, Examples 1 and 2 of the present invention is significantly less than the latex content of Comparative Example 1, despite the latex content in the same amount as Comparative Example 2, can obtain a significantly superior bending strength improvement effect of about 13% or more It can be seen.

In this way, a low-cost nylon fiber reinforcement material can be used to manufacture latex modified concrete of excellent physical properties corresponding to latex, which is an expensive raw material, and can be used to construct a high-durability nylon fiber reinforced LMC with more economical and durability. It can be seen.

In the present invention, by mixing the fiber reinforcing material in the latex-modified concrete composition, it is possible to obtain the effects of suppressing the occurrence of cracks, increasing the flexural strength, preventing partial dropout when the cracks occur. In particular, it is possible to maintain excellent performance while minimizing the latex content has an excellent effect in terms of economics, it is possible to effectively construct a structurally stable package by increasing the bending strength.

In addition, by adding carbon black resistant to ultraviolet rays, the durability of latex-modified concrete can be improved, and the color of the concrete can be changed to black to improve lane clarity, thereby securing the safety of the driving vehicle. This is very large.

Figure 1a is a photograph showing the ductile fracture phenomenon of the specimen after the fracture test of the fiber reinforced LMC according to Example 1 of the present invention

Figure 1b is a photograph showing the brittle fracture phenomenon of the specimen after the fracture test of the existing LMC according to Comparative Example 1 of the present invention.

FIG. 2A is a photograph of a specimen before and after abrasion loss test to check the amount of wear of the fiber reinforced LMC according to Example 1 of the present invention.

Figure 2b is a photograph of the specimen before wear and wear test after the wear loss test to confirm the amount of wear of the existing LMC according to Comparative Example 1 of the present invention.

Claims (13)

A latex modified concrete composition comprising cement, latex, and aggregate, wherein the latex modified concrete composition further comprises a fiber reinforcement having a relative viscosity (RV) of 2.9 or more in an amount of 0.5 to 1.5 parts by weight based on 100 parts by weight of cement. The method of claim 1, The fiber reinforcing material is at least one selected from the group consisting of polyamide fiber, polyethylene fiber, polyacrylic fiber, polyester fiber, polypropylene fiber, polyvinyl alcohol fiber, cellulose fiber latex modified concrete composition. delete The method of claim 1, Latex modified concrete composition comprising a fiber reinforcement 2.0 to 6.0 kg / m ³ with respect to the concrete unit volume. The method of claim 1, Latex modified concrete composition comprising a latex in 10 to 32 parts by weight based on 100 parts by weight of cement. The method of claim 1, Latex modified concrete composition comprising a latex 40 to 128 kg / m ³ with respect to the concrete unit volume. The method of claim 1, The fiber reinforcement and latex is a latex modified concrete composition having a content ratio of 1:10 to 1:35 by weight. The method of claim 1, Latex modified concrete composition comprising water in 322 to 285 parts by weight based on 100 parts by weight of cement. The method of claim 1, Latex modified concrete composition comprising a coarse aggregate in 177 to 182 parts by weight based on 100 parts by weight of cement. The method of claim 1, Latex modified concrete composition comprising a fine aggregate 235 to 240 parts by weight based on 100 parts by weight of cement. The method of claim 1, Latex modified concrete composition further comprises 0.5 to 1.5 parts by weight of carbon black based on 100 parts by weight of cement. A latex modified concrete prepared using the composition according to any one of claims 1 to 2 or 4 to 11, having a slump of 160 to 220 mm and an air volume of 3% to 6%. The method of claim 12, The bending strength measured according to the KS F2408 method is 5 to 6 N / mm ² , the compressive strength measured according to the KS F2405 method is 36 to 38 N / mm ² , and the wear loss measured according to the KS F2508 method is measured before the measurement. Latex modified concrete that is 12-14% by weight.

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