KR102432365B1 - Fiber reinforced contrete compostion containg recycle resin - Google Patents

Abstract

The present invention relates to a fiber-reinforced concrete composition including a regenerated resin. Specifically, polyamide (PA) and polypropylene (PP) generated as by-products in the composite manufacturing process instead of expensive high-strength fibers and organic fibers , including reinforcing fibers impregnated with a thermoplastic resin such as polyethylene (PE), can have the effect of not only realizing similar performance to conventional organic fiber and steel fiber reinforced concrete, but also securing economic feasibility.

Description

Fiber reinforced concrete composition containing recycled resin {Fiber reinforced contrete composition containg recycle resin}

The present invention relates to a fiber-reinforced composite material impregnated with a thermoplastic resin required to enhance tensile strength and flexural strength in a concrete composition comprising water, cement, fine aggregate, coarse aggregate and water reducing material 0.1% to 3% based on the concrete volume It relates to a fiber-reinforced concrete composition comprising a range.

Compostie refers to a material made by artificially mixing or combining materials having different components and properties to maximize the properties of each material or to have new properties that are not expressed in a single material. Composite materials are fundamentally superior in physical properties such as strength, corrosion resistance, fatigue life, abrasion resistance, impact resistance, and lightness compared to conventional materials. It is a representative 21st century industrial material that is in the spotlight in the field.

In particular, composite materials can be broadly divided into two types depending on their shape. They are in the form of pellets cut so that kneading in the screw is smooth because they can be put into the injection molding machine, and in the continuous direction (UD) of long tapes without single yarns. In some cases, it is produced in a shape, and the by-products generated by changing the position and shape and realizing a uniform width during the manufacture of the composite are generated in a large amount in a very diverse form at the end face of the product and in the initial and final products. Normally, the by-products generated at this time are disposed of through separate collection, or in the case of thermoplastic composite materials, they can be used after heating again to soften them, so they are mainly used by general reclaimed product molding companies. However, in this case, the by-product must be transported to the molding site, and the transportation cost is excessive due to the volume, so the economic effect is not large.

In addition, when manufacturing recycled products, not only by-products are used, but scrap products collected in various ways are mixed and used. It has the disadvantage of lowering the marketability due to different product deformation or uneven appearance quality.

In addition, in the case of concrete made using only basic water, cement, fine aggregate, and coarse aggregate, its economical efficiency and durability are excellent, so it is widely used in building structures along with steel materials. During flow setting, microcracks due to hardening shrinkage occur, which affects the strength of concrete structures large and small.

Such cracks in concrete are caused by various causes, but among them, shrinkage after drying and plastic shrinkage are the main causes of cracking. These cracks affect low mechanical properties and deterioration of concrete durability, and furthermore, as a source of serious cracks, they may have a potential impact on major accidents. In addition, in the case of ultra-high-strength concrete, it has high compressive strength due to its characteristics, and this causes brittle fracture due to the disadvantage of weakening brittleness, which causes serious damage when vibrations such as earthquakes occur. .

In addition, in order to improve such a problem in the prior art, it is difficult to expect the separation of the fibers and a clear crack improvement effect, although a technique for using a portion of the tensile strength and flexural strength by injecting steel fibers and organic fibers has been improved.

In addition, conventionally, in order to improve separation from concrete, organic fibers such as polyvinyl alcohol (PVA), polyamide (PA), and polyethylene (PE), glass fiber, steel fiber, carbon fiber, etc. are hybridized to mix various types of fibers. However, since the characteristics of different types of fibers are not properly reflected, and organic fibers and reinforcing fibers are separately manufactured for concrete input, sufficient economic feasibility cannot be ensured, making it impossible to maximize the amount of material input. It has limitations.

The present invention is an impregnated thermoplastic resin such as polyamide (PA), polypropylene (PP), and polyethylene (PE) generated as a by-product in the composite manufacturing process for reinforcing fibers required to improve tensile and flexural strength in concrete production. By using the reinforcing fiber by-product, it can be expected to not only realize performance similar to that of conventional organic fiber and steel fiber reinforced concrete, but also to secure manufacturing economical efficiency.

An object of the present invention is to provide a technology for standardizing the by-products of the first and last products generated during the continuous production of thermoplastic composites, and the side yarn (mimi) cutting scraps generated during the production of continuous fiber tapes to be inputted during the production of concrete.

In addition, the embodiments of the present invention utilize the by-products generated during the manufacture of the composite resin and include them in the concrete composition, thereby satisfying the tensile strength and flexural strength similar to that of fiber-reinforced concrete of the prior art, as well as securing economic feasibility, making it a general-purpose building material It is intended to provide a technology for easy application to phosphorus concrete.

In a preferred embodiment of the present invention, in the concrete composition comprising water, cement, fine aggregate, coarse aggregate and water reducing material, the thermoplastic composite material by-product is contained in an amount of 0.1 to 3% based on the volume, and the thermoplastic composite material by-product is To provide a fiber-reinforced concrete composition that is a reinforcing fiber impregnated with a thermoplastic resin.

The reinforcing fiber impregnated with the thermoplastic resin is characterized in that the length of the fiber length is 5 to 40 mm.

The reinforcing fibers impregnated with the thermoplastic resin have a density of 1.1 to 1.7 g/cm 3 .

The reinforcing fiber is characterized in that at least one selected from glass fiber, carbon fiber, aramid fiber and basalt fiber.

The thermoplastic resin is characterized in that at least one selected from polyolefin resin, polypropylene, polyamide, and polyphenyl sulfide.

The composition is characterized in that the water/binder ratio (W/B) is 25-40% by volume, the fine aggregate ratio is 40-65% by volume, and the average air amount is 1-5% by volume with respect to the composition.

The composition is characterized in that it further comprises at least one additive selected from the group consisting of a thickener, an air entraining agent, a waterproofing agent, a foaming agent, a water reducing agent and an antifoaming agent.

The fiber-reinforced concrete composition including the regenerated resin according to the present invention can improve tensile strength and flexural strength characteristics.

In addition, according to the present invention, it can be expected to reduce wastes that cause environmental pollution, including by-products generated during the manufacture of composite materials.

In addition, according to the present invention, it is possible to replace the conventional organic fiber and steel fiber for the utilization range of the composite material by-product, so that economic effects can be expected.

1 is a photograph taken of a by-product of a thermoplastic composite material according to an embodiment of the present invention.
2 is a graph measuring the compressive strength of Examples 1 to 5 and Comparative Examples.
3 is a graph measuring the flexural strength of Examples 1 to 5 and Comparative Examples.

According to a preferred embodiment of the present invention, in the concrete composition comprising water, cement, fine aggregate, coarse aggregate and water reducing material, the thermoplastic composite material by-product is contained in an amount of 0.1 to 3% based on the volume, and the thermoplastic composite material The by-product is to provide a fiber-reinforced concrete composition that is a reinforced fiber impregnated with a thermoplastic resin.

In addition, it should be considered that the contents (%) and ratios expressed in the examples and means for the invention are all composed on the basis of the volume.

The thermoplastic composite material by-product is preferably included in an amount of 0.1 to 3%. If it is less than 0.1% of the concrete volume, it is difficult to expect improvement in tensile strength and flexural strength. If it exceeds 3% of the concrete volume, it may be appropriately considered depending on some usage environments, but the input price and the original compressive strength of concrete It may cause a problem of deterioration of physical properties, and may not be economical considering the price of the input by-products.

In addition, the thermoplastic composite material by-product mainly has a colorless or black color, and in the case of black, it can be seen as an external black spot after concrete mixing and curing. .

At this time, the production of the thermoplastic composite material by-product includes the composite material produced in the unstable continuous production process caused at the start and end of the composite material production, and also removes for uniform production in the width direction of the product in the continuous production process. It can be manufactured by inputting the side yarn (Mimi) with a separate cutter.

1 is a photograph taken of a by-product of a thermoplastic composite material according to an embodiment of the present invention. As shown in Figure 1, the thermoplastic composite by-product can be adjusted to various lengths, which can be adjusted according to the required strength and performance level of Portland cement. The by-product according to the present invention is made from a continuous fiber reinforced composite. Specifically, the fiber length is not initially cut in the continuous (UD) direction, and it can be used by cutting it into a shape required for manufacturing by-products. Therefore, the length of the fiber length and the length of the by-product are the same.

The reinforcing fiber impregnated with the thermoplastic resin preferably has a length of 5 to 40 mm. If the length of the fiber length is less than 5 mm, there is a high possibility that the adhesion to concrete will decrease, and if it exceeds 40 mm, the adhesion may be advantageous, but the dispersibility may deteriorate and the performance may become non-uniform.

The reinforcing fibers impregnated with the thermoplastic resin preferably have a specific gravity of 1.1 to 1.7 g/cm 3 .

The reinforcing fiber is preferably at least one selected from glass fiber, carbon fiber, aramid fiber and basalt fiber.

In the reinforcing fibers impregnated with the thermoplastic resin, the thermoplastic resin is preferably at least one selected from polyolefin resin, polypropylene, and polyamide.

In particular, the by-product of the thermoplastic composite material included in the concrete composition can be composed of mainly using a polyolefin-based resin that satisfies corrosion resistance. Considering the large aspect ratio during kneading, the adhesion area with concrete increases to improve the properties of concrete. It is advantageous because it can be controlled effectively, but it is preferable to select the fiber in consideration of the price of the fiber used in the production of the thermoplastic composite material and the physical properties of the material to be impregnated.

Since the fibers included in the concrete composition serve to improve the internal dispersibility and adhesion performance during concrete construction and curing, the thermoplastic composite material by-product may be accompanied by a separate treatment on the surface to play such a role.

In addition, in order to maximize the affinity and compatibility with different materials due to the characteristics of the composite material, it can be manufactured by adding 3 to 15% of the compatibilizer based on the volume in the composite material manufacturing process. In order to improve the environmental durability of concrete performance, additives with separate erosion resistance, chemical resistance, and abrasion resistance may be added when manufacturing a composite material, and accordingly, the properties or shape of the composite material by-product may be changed.

The above-described fiber-reinforced concrete composition preferably has a water binder ratio of 25 to 40%, a fine aggregate ratio of 40 to 65%, and an average air amount of 1 to 5%.

The water/binder ratio (W/B) means a ratio of water and cement, and the binder is defined as cement and admixture.

The fine aggregate ratio means a percentage of the absolute volume of the fine aggregate to the sum of the absolute volumes of the fine aggregate and the coarse aggregate. In other words, it means that small sand and gravel are put in as much as the corresponding proportion of the concrete volume.

When describing the amount of air, the internal structure of concrete inevitably generates air in the process of using and manufacturing the composite material. At this time, the generated air is related to the performance of the hardened concrete. If the amount of air is excessive, the strength decreases and cracks occur. If it is appropriate, the freezing resistance becomes excellent. In this respect, in the present invention, it is preferable to satisfy the average air amount of 1 to 5%.

If the water binder ratio is less than 25%, cracks are highly likely to occur after curing, and if it exceeds 40%, a lack of rigidity may occur.

In addition, the fine aggregate ratio must be maintained at 40 to 65% mixing to maintain the average air volume, and when it is less than 40% or exceeds 65%, workability deterioration, adhesion failure, and concrete properties deterioration may occur.

In addition, if the average air amount is less than 1%, workability may be reduced, and if it exceeds 5%, the adhesion between the thermoplastic composite material and aggregate may be deteriorated, so it is preferable to configure within the above range.

The fiber-reinforced concrete composition may add additional erosion resistance, corrosion resistance, chemical resistance, and abrasion resistance additives to improve concrete performance, and accordingly, the properties or shape of the composite material by-product may be changed.

Example

Hereinafter, the present invention will be described in more detail through examples. These examples are only for illustrating the present invention in more detail, and the present invention is not limited thereto.

Example 1 to 5 and comparative example One

Concrete was prepared by a conventional method with the contents and components shown in Table 1 below. At this time, the content of the thermoplastic composite material by-product and water reducing agent is a weight % based on the total solid content in the composition.

Thermoplastic Composite by-product Water/Binder Ratio (W/B) (%) Fine aggregate rate (%) Unit mass (kg/m3) water reducing agent water cement fine aggregate coarse aggregate Comparative Example 1 ^* 0.5 35 55 200 570 730 892 1.5 Example 1 0.1 Example 2 0.5 Example 3 One Example 4 2 Example 5 3

Note) *: In Comparative Example 1, a reinforcing agent for admixture was added instead of the thermoplastic composite material by-product.

In Comparative Example 1, as shown in Table 1, the water/binder ratio (W/B) was 35%, the fine aggregate ratio was 55%, the target slump and the air amount were 180 ± 25 mm, respectively, and the air amount was 3 ± 1.5%. . The slump is a criterion for confirming how much it collapses and is disturbed when the compound is put into the concrete slump cone and the slump cone is removed. In other words, if there is a slump of 150 or 180, it means that 180 has collapsed more, and this is because the amount of water in 180 is higher than 150.

In addition, the amount of heat-setting composite material by-product was added in an amount of 0.1 to 3% by weight relative to the total solid content in the concrete composition, and according to KS F 2403, for compressive strength test (Φ100x200mm) and flexural strength test (100x100x400mm) concrete specimens were manufactured.

In addition, the admixture reinforcing agent added in Comparative Example 1 was not impregnated, and was prepared by mixing amorphous steel fiber (ASF) and polyamide fiber in a weight ratio of 1:1. That is, the steel fiber is literally made of steel like a stapler core, and the polyamide fiber itself is manufactured in a form similar to that of the steel fiber.

In particular, for the cement of Comparative Example 1 and Examples 1 to 5, ordinary Portland cement (Asia cement) was used, and for the fine aggregate, Nakdonggangsan river sand produced in Uiryeong, Gyeongnam was used, and coarse aggregates produced in the same area were also used. did. In addition, in the case of a water reducing agent, a liquid high performance water reducing agent of Sanofco's polycarboxylic acid was used.

In addition, the thermoplastic composite material by-products according to Examples 1 to 5 used polypropylene (PP)-impregnated glass fiber, the length of the fiber length was 11 mm, and the density was 1.48 g/cm 3 .

For compressive strength, a 7-day strength test was performed according to KS L ISO 679, and the flexural strength shows the 7-day flexural strength according to the amount of concrete fiber input.

2 is a graph measuring the compressive strength of Examples 1 to 5 and Comparative Example, and FIG. 3 is a graph measuring the flexural strength of Examples 1 to 5 and Comparative Example.

According to the evaluation results with reference to FIGS. 2 and 3, it was found that the compressive strength decreased when the mixing amount was large in proportion to the input amount of the by-product of the thermoplastic composite material. However, in the case of flexural strength, it was found to have an improvement effect, and therefore it was confirmed that it can be used effectively in concrete mixing requiring improvement of tensile strength and flexural strength.

Claims (7)

In the concrete composition comprising water, cement, fine aggregate, coarse aggregate and water reducing material,
It contains 0.1 to 3% by volume of the thermoplastic composite material by-product,
The thermoplastic composite material by-product is a reinforcing fiber impregnated with a thermoplastic resin,
The reinforcing fiber is a glass fiber,
The reinforcing fiber impregnated with the thermoplastic resin is in the form of a tape including continuous fibers,
The fiber-reinforced concrete composition of the reinforcing fibers impregnated with the thermoplastic resin has a length of 5 to 11 mm and a density of 1.48 to 1.7 g/cm 3 . delete delete The fiber-reinforced concrete composition according to claim 1, wherein the reinforcing fiber further comprises at least one selected from carbon fiber, aramid fiber, and basalt fiber. The fiber-reinforced concrete composition according to claim 1, wherein the thermoplastic resin is at least one selected from polyolefin resin, polypropylene, and polyamide. The composition according to claim 1, wherein the composition has a water/binder ratio (W/B) of 25 to 40% by volume, a fine aggregate ratio of 40 to 65% by volume, and an average air amount of 1 to 5% by volume. Fiber-reinforced concrete composition. The fiber-reinforced concrete composition according to claim 1, wherein the composition further comprises at least one additive selected from the group consisting of a thickener, an air entraining agent, a waterproofing agent, a foaming agent, a water reducing agent, and an antifoaming agent.

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