KR20170076146A

KR20170076146A - Cement-Mortar Composites Mixed With By-Product Of Graphene

Info

Publication number: KR20170076146A
Application number: KR1020150186048A
Authority: KR
Inventors: 엄철환
Original assignee: 대영건설주식회사
Priority date: 2015-12-24
Filing date: 2015-12-24
Publication date: 2017-07-04

Abstract

The present invention is produced by mixing graphene by-products into water, cement, and sand, and the graphene by-product is a byproduct produced in the process of producing graphene.
The graphene byproduct of the present invention is also characterized by incorporating 1% to 7% or 5% to 7% by weight of the cement.

Description

Cement-Mortar Composites Mixed With By-Product Of Graphene < RTI ID = 0.0 >

The present invention relates to a cement-mortar composite containing graphene byproducts, and more particularly, to a cement-mortar composite containing graphene byproducts which are improved in compressive strength and tensile strength by incorporating a predetermined graphene by- Lt; / RTI >

Mortar is a building material mixed with a certain proportion of cement and sand.

Recently, as the scale of the construction work has become larger and higher, the design strength of the building structure has been greatly increased, so that a mortar having high strength and high durability is desperately required.

Portland cement is a brittle material with a very low strain rate due to tensile stress as well as general ceramics and has low fracture strength, despite its excellent properties.

The cement hardened body is a porous body composed of inorganic minerals constituting the cement, its hydrate and pores. The strength of the cement hardened body is basically the strength of the hydrate aggregate, but it depends on the size of porosity and porosity since it is a porous body.

In general, the relatively low strength of cement hardened bodies has been attempted to eliminate such defects due to defects such as cracks and voids existing in the cement hardened body and on the surface, and ultrafine particles can be used to improve the filling property of the particles And densified system containing homogeneously arranged ultrafine particles (DSP) cement materials are used to combine dispersant and ultrafine powder in Portland cement and knead it in a very small amount of work to reduce voids and enable compact molding. This material is patented by H.H.Bache of Denmark (PCT / DK81 / 00048) and is widely applied as a cement concrete material for high strength development.

However, the cement material has a very homogeneous matrix, which greatly improves the compressive strength. However, the improvement in flexural strength, toughness and impact resistance is insignificant compared to the compressive strength. Therefore, efforts have been made to add fibers or to compound polymers that are organic compounds in order to compensate for these problems. Especially, the composite of cement concrete and organic material, which are inorganic materials, has been evaluated as a desirable direction for high strength, high toughness, high durability and high impact resistance of cement concrete.

Among the efforts for complexing polymers, the technique of impregnating a polymer into a cement hardened body is the latest method of composite material of polymer and cement. However, it is mainly used for improving the surface layer of concrete, that is, improving the surface strength, watertightness, chemical resistance, and abrasion resistance, even though it has excellent properties due to restrictions on the manufacturing method.

On the other hand, fiber reinforced concrete, which is produced by mixing about 1% of steel fiber and organic fiber into a mixture of ordinary concrete to prevent brittle fracture of concrete, is used in some concrete structures.

However, since the fiber reinforced concrete injects fibers into the blend of ordinary concrete, a large amount of fibers can not be supplied due to a lack of viscosity of the concrete, so that it can not secure a satisfactory toughness. Also, a fiber ball phenomenon occurs, There are cases where the performance is deteriorated. In addition, fiber content of about 1% does not completely prevent the brittle fracture of high strength concrete, and it has a vulnerability that structure is destroyed immediately when earthquake, repetitive and impact load of vehicle, fire and natural deterioration occur.

Disclosure of Invention Technical Problem [8] The present invention has been made to solve the above-mentioned problems of the prior art, and it is an object of the present invention to provide a method for producing a graphene, To provide cement-mortar composites incorporating graphene byproducts.

In order to solve the above technical problems, the present invention provides a method for producing graphene by-products, which is produced by mixing graphene by-products into water, cement and sand, Lt; RTI ID = 0.0 > cement-mortar < / RTI >

The graphene byproduct of the present invention is also characterized by incorporating 1% to 7% or 5% to 7% by weight of the cement.

As described above, according to the present invention, by mixing the above-mentioned graphene by-products in addition to cement, water, and sand, which are the conventional mortar constituting elements, a certain amount of the graphene byproduct is mixed, thereby exhibiting the effect of increasing the tensile strength by up to about 20% as well as the compressive strength.

At this time, the graphene by-products use the byproducts generated during the graphene generation process, thereby reducing the cost.

FIGS. 1A to 1G are test results on the compression strength of mortars incorporating graphene byproducts according to the present invention.
FIGS. 2A to 2H are test reports on tensile strength of mortars incorporating graphene byproducts according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIGS. 1A to 1G are test results on the compression strength of a mortar incorporating a graphene byproduct (GP) according to the present invention, and FIGS. 2A to 2H are graphs showing the tensile strength of a mortar It is the test report which tested the strength.

The present invention relates to a cement-mortar composite and is characterized in that the cement-mortar composite is produced by mixing graphene byproduct (GP) into water, cement and sand.

That is, the present invention is a method in which graphene byproduct (GP) is mixed with water, cement, and sand, which are general constituents of mortar.

Graphene is one of the carbon isotopes, and carbon atoms gather to form a two-dimensional plane. The method of manufacturing such graphene can be divided into a physical separation method and a chemical method. Since the physical separation method is difficult to generate large area graphene, a chemical method is recently used. However, these chemical methods produce low-quality graphene, such as unstable graphene sheets, which break apart as well as high-quality graphene.

A low-quality graphene by-product (GP) made of such low-quality graphene is a constituent of the present invention. For example, a low-quality graphene by-product formed in micrometer (탆) (GP) may be used. Of course, the present invention does not use high-quality graphene used in semiconductors and the like in consideration of economical efficiency, but low-quality graphene in nanometer (nm) generated in the process of manufacturing graphene can also be used.

The test results of the cement-mortar composite incorporating such graphene byproduct (GP) can be seen in Figs. 1A to 1G and Figs. 2A to 2H. The average values of the test results of the respective specimens are shown in the table below .

Specimen
Strength (MPa) Compressive strength The tensile strength GM00 37.3 2.0 GM01 41.6 2.2 GM02 42.8 2.1 GM03 44.2 2.2 GM04 44.2 2.2 GM05 44.2 2.3 GM06 44.9 2.4 GM07 44.0 2.4 GM08 39.2 2.1 GM09 34.5 1.9 GM10 32.5 1.5 GM15 30.1 1.4 GM20 28.3 1.1

Experiments on the above results were carried out according to the test and inspection methods of KS L 5105 (compressive strength) and KS L 5104 (tensile strength), and the water-cement ratio of each specimen was the same according to KS regulations.

The number after the GM indicates the weight ratio of graphene to cement. For example, in the case of GM01, it means that graphene is mixed with 1% by weight of cement.

Here, it is preferable that the graphene byproduct (GP) is mixed with 1% to 7% of the cement weight, as shown in Table 1 above, since the compression strength is at least 10% higher than that of the reference sample not containing the graphene by- This is because it shows the effect of increasing up to 20%.

As described above, the cement-mortar composite according to the present invention can be effectively used for long-span and mass concrete without increasing the thickness due to excellent compressive strength characteristics, and also can prevent environmental pollution caused by recycling of graphene by- product (GP) And the cost reduction effect can be obtained.

Also, considering the tensile strength, it is preferable that the graphene byproduct (GP) be mixed with 5 to 7% of the cement weight.

That is, as shown in Table 1 above, it can be seen that the tensile strength of the reference specimen is increased by 15% to 20% as well as the compressive strength when the graphene byproduct (GP) is mixed with 5% to 7% of the cement weight.

Conventionally, there has been a case where carbon fiber or the like is mixed in order to increase the tensile strength of concrete. In this case, when a large amount of carbon fiber is mixed, a synergistic effect of compressive strength is low and manufacturing cost is increased. On the contrary, the present invention exhibits the effect of simultaneously enhancing the compressive strength and the tensile strength at a low cost by incorporating the graphene byproduct (GP) in an amount of 5% to 7% by weight of the cement.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present invention as defined by the appended claims. And it is to be understood that such modified embodiments belong to the scope of protection of the present invention defined by the appended claims.

GP: Graphene byproduct

Claims

Water, cement, and sand by incorporating graphene byproduct (GP)
Wherein the graphene byproduct (GP) is a byproduct produced in the process of producing graphene.

The method of claim 1,
Wherein said graphene byproduct (GP) is incorporated between 1% and 7% of the weight of the cement.

The method of claim 1,
Characterized in that the graphene byproduct (GP) is incorporated between 5% and 7% of the weight of the cement.

4. The method according to any one of claims 1 to 3,
Characterized in that the graphene by-product (GP) is formed in micrometer (m) in granular size.