阅读说明：本技术 一种氧化石墨烯增强铁尾矿陶粒混凝土及其制备方法 (Graphene oxide reinforced iron tailing ceramsite concrete and preparation method thereof ) 是由 李晓光 屈雅安 陶斌 王旭 于 2021-07-22 设计创作，主要内容包括：本发明属于工程材料技术领域,公开了一种氧化石墨烯增强铁尾矿陶粒混凝土及其制备方法,包括以下制备原料：水泥基胶凝材料、氧化石墨烯、粗骨料、石英砂、减水剂和水。可明显提高铁尾矿陶粒混凝土的抗压强度、劈裂抗拉强度和弹性模量,显著提高陶粒混凝土的安全性以及扩大其在建筑行业的应用范围；其制备方法简单,造价成本低廉,便于工业化生产及应用,可适用于装配式建筑的非承重构建,显著降低其安全风险。(The invention belongs to the technical field of engineering materials, and discloses graphene oxide reinforced iron tailing ceramsite concrete and a preparation method thereof, wherein the graphene oxide reinforced iron tailing ceramsite concrete comprises the following preparation raw materials: the concrete comprises a cement-based cementing material, graphene oxide, coarse aggregate, quartz sand, a water reducing agent and water. The compression strength, the splitting tensile strength and the elastic modulus of the iron tailing ceramsite concrete can be obviously improved, the safety of the ceramsite concrete is obviously improved, and the application range of the ceramsite concrete in the building industry is expanded; the preparation method is simple, low in manufacturing cost and convenient for industrial production and application, and is suitable for non-bearing construction of the fabricated building, so that the safety risk of the fabricated building is remarkably reduced.)

1. The graphene oxide reinforced iron tailing ceramsite concrete is characterized by comprising the following preparation raw materials: the concrete comprises a cement-based cementing material, graphene oxide, coarse aggregate, quartz sand, a water reducing agent and water.

2. The graphene oxide reinforced iron tailing ceramsite concrete according to claim 1, wherein the raw materials are used in the following amounts: 30.1-34.6% of coarse aggregate, 34.4-38.3% of quartz sand, 21.1-25.2% of cement-based cementing material and 7.8-8.6% of water; the graphene oxide accounts for 0.02-0.10% of the mass of the cement-based cementing material; the water reducing agent accounts for 1.70-2.15% of the mass of the cement-based cementing material.

3. The graphene oxide reinforced iron tailing ceramsite concrete according to claim 1, wherein the cement-based cementing material comprises ordinary portland cement with a strength grade of 42.5 and more than two grades of fly ash.

4. The graphene oxide reinforced iron tailing ceramsite concrete according to claim 3, wherein the median diameter of the ordinary portland cement is 11.02-15.10 μm; the activity of the fly ash is 65-70%.

5. The graphene oxide reinforced iron tailing ceramsite concrete according to claim 1, wherein the graphene oxide has a specific surface area of 700-1500 m²A single-layer carbon nano-sheet with the length-width ratio of 2500-10000, the elastic modulus of 25-35 GPa, the tensile strength of 126-135 MPa and the diameter of 0.7-5 nm.

6. The graphene oxide reinforced iron tailing ceramsite concrete according to claim 1, wherein the coarse aggregate is iron tailing ceramsite; the water reducing agent is a polycarboxylic acid water reducing agent, and the water reducing rate of the water reducing agent is 20-30%.

7. The graphene oxide reinforced iron tailing ceramsite concrete according to claim 1, wherein the purity of the quartz sand is 97% -99%, and the fineness modulus is 0.75-1.23.

8. The preparation method of the graphene oxide reinforced iron tailing ceramsite concrete is characterized by comprising the following steps:

step 1, mixing and stirring graphene oxide and water, and then performing ultrasonic dispersion to obtain a graphene oxide aqueous solution;

step 2, mixing and stirring the graphene oxide aqueous solution and a water reducing agent to obtain an aqueous solution;

step 3, mixing the coarse aggregate, the quartz sand and the cement-based cementing material, and stirring to obtain a mixture;

and 4, mixing the water agent, the mixture and water, and stirring to obtain the graphene oxide reinforced iron tailing ceramsite concrete.

9. The preparation method of the graphene oxide reinforced iron tailing ceramsite concrete according to claim 8, wherein in the step 1, the ultrasonic power for ultrasonic dispersion is 971-1126 w, the time interval for ultrasonic dispersion is 1-4s, and the dispersion time for ultrasonic dispersion is 40-80 min; the using amount ratio of water in the step 1 and the step 4 is 7: 3; the stirring speed is 700-900rpm, and the stirring time is 5-10 minutes.

10. The preparation method of the graphene oxide reinforced iron tailing ceramsite concrete according to claim 8, wherein in the step 3 and the step 4, the concrete mixer is adopted for stirring, and the stirring is firstly carried out at a low speed for 5min, then is carried out at a high speed for 10min, and finally is carried out at a low speed for 3 min; the low speed is 145 +/-5 r/min of autorotation and 60 +/-5 r/min of revolution of the concrete mixer; the high speed is that the concrete mixer rotates 275 +/-10 r/min and revolves 120 +/-10 r/min.

Technical Field

The invention relates to the technical field of engineering materials, and particularly relates to graphene oxide reinforced iron tailing ceramsite concrete and a preparation method thereof.

Background

Until now, ordinary portland cement is still the first choice building material in the civil engineering field, and is a cementing material which cannot be replaced in construction due to wide source and low price. However, cement-based cementitious materials have the disadvantage of limited strain capacity, resulting in poor crack resistance and tensile properties.

The nano material has obvious promotion effect on the hydration process of cement due to the unique material property. The adhesion phenomenon is generated by the interaction of the nano material and the cement on the nano scale, so that the strength and the compactness of the cement-based cementing material are obviously improved. Compared with common fibers, the graphene oxide has a reasonable and more appropriate length-diameter ratio in the aspect of enhancing the performance of the cement-based cementing material. In the aspect of hydration reaction, the graphene oxide plays a seed crystal role in cement hydration and promotes the growth of hydration products. The breaking form of the set cement is known, and the graphene oxide can improve the ductility of the set cement.

At present, the ceramsite concrete is mainly applied to non-bearing components such as heat-insulating wall boards, stairs, internal and external partition boards and the like in an assembly type building. With the further development of the fabricated building in the future, the performance of the ceramsite concrete is improved to be of great importance. Therefore, the fabricated building becomes the mainstream direction of the building industry, and the ceramsite concrete also becomes one of the mainstream building materials of the building industry. Compared with common concrete, the ceramsite concrete has the characteristics of light self weight, good fire resistance, good shock resistance and good freezing resistance, but when the ceramsite concrete and the common concrete have the same water-cement ratio, the mechanical property of the ceramsite concrete is obviously lower than that of the common concrete, and the development and the application of the ceramsite concrete are hindered due to the defect of the mechanical property of the ceramsite concrete.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide the graphene oxide reinforced iron tailing ceramsite concrete and the preparation method thereof, which can obviously improve the compressive strength, the splitting tensile strength and the elastic modulus of the iron tailing ceramsite concrete, obviously improve the safety of the ceramsite concrete and expand the application range of the ceramsite concrete in the building industry; the preparation method is simple, low in manufacturing cost and convenient for industrial production and application, and is suitable for non-bearing construction of the fabricated building, so that the safety risk of the fabricated building is remarkably reduced.

In order to achieve the purpose, the invention is realized by adopting the following technical scheme.

The graphene oxide reinforced iron tailing ceramsite concrete comprises the following preparation raw materials: the concrete comprises a cement-based cementing material, graphene oxide, coarse aggregate, quartz sand, a water reducing agent and water.

Preferably, the raw materials are used in the following amounts: 30.1-34.6% of coarse aggregate, 34.4-38.3% of quartz sand, 21.1-25.2% of cement-based cementing material and 7.8-8.6% of water; the graphene oxide accounts for 0.02-0.10% of the mass of the cement-based cementing material; the water reducing agent accounts for 1.70-2.15% of the mass of the cement-based cementing material.

Preferably, the cement-based cementing material comprises ordinary portland cement with a strength grade of 42.5 and more than two grades of fly ash.

More preferably, the median diameter (D50) of the ordinary portland cement is 11.02-15.10 μm.

More preferably, the activity of the fly ash is 65-70%.

Preferably, the graphene oxide has a specific surface area of 700-1500 m²A single-layer carbon nano-sheet with the length-width ratio of 2500-10000, the elastic modulus of 25-35 GPa, the tensile strength of 126-135 MPa and the diameter of 0.7-5 nm.

Preferably, the coarse aggregate is iron tailing ceramsite.

Preferably, the water reducing agent is a polycarboxylic acid water reducing agent, and the water reducing rate of the water reducing agent is 20-30%.

Preferably, the purity of the quartz sand is 97-99%, and the fineness modulus is 0.75-1.23.

(II) the preparation method of the graphene oxide reinforced iron tailing ceramsite concrete comprises the following steps:

step 1, mixing and stirring graphene oxide and water, and then performing ultrasonic dispersion to obtain a graphene oxide aqueous solution;

step 2, mixing and stirring the graphene oxide aqueous solution and a water reducing agent to obtain an aqueous solution;

step 3, mixing the coarse aggregate, the quartz sand and the cement-based cementing material, and stirring to obtain a mixture;

and 4, mixing the water agent, the mixture and water, and stirring to obtain the graphene oxide reinforced iron tailing ceramsite concrete.

Preferably, in the step 1, the ultrasonic power for ultrasonic dispersion is 971-1126 w, the time interval for ultrasonic dispersion is 1-4s, and the dispersion time for ultrasonic dispersion is 40-80 min.

Preferably, the ratio of water used in step 1 to step 4 is 7: 3.

Preferably, in step 1, the stirring speed is 700-900rpm, and the stirring time is 5-10 minutes.

Preferably, in the step 2, the stirring is manual stirring, and the stirring time is 5-10 min.

Preferably, in the step 3 and the step 4, the concrete mixer is adopted for stirring, and the stirring is firstly low-speed stirring for 5min, then high-speed stirring for 10min, and finally low-speed stirring for 3 min; the low speed is 145 +/-5 r/min of autorotation and 60 +/-5 r/min of revolution of the concrete mixer; the high speed is that the concrete mixer rotates 275 +/-10 r/min and revolves 120 +/-10 r/min.

Compared with the prior art, the invention has the beneficial effects that:

(1) the graphene oxide reinforced iron tailing ceramsite concrete provided by the invention can obviously improve the compressive strength, the flexural strength and the fracture toughness of the graphene oxide reinforced iron tailing ceramsite concrete. The graphene oxide reinforced iron tailing ceramsite concrete prepared by using different contents of graphene oxide has better durability, has higher compressive strength and flexural strength in 28 days, is optimal when the graphene oxide accounts for 0.02-0.04% of the mass of the cement-based cementing material, has obviously improved compressive strength, tensile strength and elastic modulus compared with the comparative example 1, and can be suitable for non-bearing members of fabricated buildings.

(2) The graphene oxide reinforced iron tailing ceramsite concrete provided by the invention does not influence the elastic modulus of the concrete, and the preparation method of the graphene oxide reinforced iron tailing ceramsite concrete is simple, low in price and convenient for industrial production and application.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to examples, but it will be understood by those skilled in the art that the following examples are only illustrative of the present invention and should not be construed as limiting the scope of the present invention.

Example 1

The graphene oxide reinforced iron tailing ceramsite concrete comprises the following raw materials in percentage by mass:

31.8 percent of coarse aggregate iron tailing ceramsite, 36.5 percent of quartz sand with fineness modulus of 1.13, 23.4 percent of cement-based gelling material and 8.3 percent of water; the graphene oxide accounts for 0.02% of the mass of the cement-based cementing material, and the polycarboxylic acid high-efficiency water reducing agent accounts for 2.0% of the mass of the cement-based cementing material. Wherein the barrel pressure strength of the iron tailing ceramsite is 5.43MPa, and the bulk density of the iron tailing ceramsite is 811kg/m³1756kg/m of apparent density³And the water absorption rate is 5.94 percent. The cement-based cementing material comprises ordinary portland cement with the strength grade of 42.5 and more than two grades of fly ash, wherein the median diameter (D50) of the portland cement is 11.02-15.10 mu m, and the activity of the fly ash is 68%. The specific surface area of the graphene oxide is 1000m²A single-layer carbon nano sheet with the diameter of 2.5nm, the length-width ratio of 3000, the elastic modulus of 32GPa, the tensile strength of 130MPa and the diameter of 32 GPa. The alkali water rate of the polycarboxylic acid high-efficiency water reducing agent is 25.5 percent. The purity of the quartz sand was 97%.

The preparation method of the graphene oxide reinforced iron tailing ceramsite concrete comprises the following preparation steps:

step 1, mixing graphene oxide with 5.81% of water, stirring for 5 minutes at a stirring speed of 800rpm, performing ultrasonic dispersion at a power of 1030w every 3 seconds for 60 minutes to obtain a graphene oxide aqueous solution.

And 2, mixing the graphene oxide aqueous solution with the polycarboxylic acid high-efficiency water reducing agent, and manually and slowly stirring for 5min to obtain the aqueous solution.

And 3, mixing the coarse aggregate, the quartz sand and the cement-based cementing material, firstly stirring for 5min at a low speed of 145 +/-5 r/min and 60 +/-5 r/min in a revolution by adopting a concrete stirrer, then stirring for 10min at a high speed of 275 +/-10 r/min in a rotation manner and 120 +/-10 r/min in a revolution manner, and finally stirring for 3min at a low speed of 145 +/-5 r/min in a rotation manner and 60 +/-5 r/min in a revolution manner to obtain a mixture.

And 4, mixing the aqueous agent and the mixture with 2.49 percent of water, firstly stirring for 5min at a low speed of 145 +/-5 r/min and 60 +/-5 r/min in a revolution by using a concrete stirrer, then stirring for 10min at a high speed of 275 +/-10 r/min in a rotation manner and 120 +/-10 r/min in a revolution manner, and finally stirring for 3min at a low speed of 145 +/-5 r/min in a rotation manner and 60 +/-5 r/min in a revolution manner to obtain the graphene oxide reinforced iron tailing ceramsite concrete.

Example 2

The graphene oxide reinforced iron tailing ceramsite concrete comprises the following raw materials in percentage by mass:

31.8 percent of coarse aggregate iron tailing ceramsite, 36.5 percent of quartz sand with fineness modulus of 1.13, 23.4 percent of cement-based gelling material and 8.3 percent of water; the graphene oxide accounts for 0.04% of the mass of the cement-based cementing material, and the polycarboxylic acid high-efficiency water reducing agent accounts for 2.0% of the mass of the cement-based cementing material. Wherein the barrel pressure strength of the iron tailing ceramsite is 5.43MPa, and the bulk density of the iron tailing ceramsite is 811kg/m³1756kg/m of apparent density³And the water absorption rate is 5.94 percent. The cement-based cementing material comprises ordinary portland cement with the strength grade of 42.5 and more than two grades of fly ash, wherein the median diameter (D50) of the portland cement is 11.02-15.10 mu m, and the activity of the fly ash is 68%. The specific surface area of the graphene oxide is 1000m²A single-layer carbon nano sheet with the diameter of 2.5nm, the length-width ratio of 3000, the elastic modulus of 32GPa, the tensile strength of 130MPa and the diameter of 32 GPa. The alkali water rate of the polycarboxylic acid high-efficiency water reducing agent is 25.5 percent. The purity of the quartz sand was 97%.

The preparation method of the graphene oxide reinforced iron tailing ceramsite concrete is the same as that in example 1.

Example 3

The graphene oxide reinforced iron tailing ceramsite concrete comprises the following raw materials in percentage by mass:

31.8 percent of coarse aggregate iron tailing ceramsite, 36.5 percent of quartz sand with fineness modulus of 1.13, 23.4 percent of cement-based gelling material and 8.3 percent of water; the graphene oxide accounts for 0.06% of the mass of the cement-based cementing material, and the polycarboxylic acid high-efficiency water reducing agent accounts for 2.0% of the mass of the cement-based cementing material. Wherein the barrel pressure strength of the iron tailing ceramsite is 5.43MPa, and the bulk density of the iron tailing ceramsite is 811kg/m³1756kg/m of apparent density³And the water absorption rate is 5.94 percent. The cement-based cementing material comprises ordinary portland cement with the strength grade of 42.5 and more than two grades of fly ash, wherein the median diameter (D50) of the portland cement is 11.02-15.10 mu m, and the activity of the fly ash is 68%. The specific surface area of the graphene oxide is 1000m²A single-layer carbon nano sheet with the diameter of 2.5nm, the length-width ratio of 3000, the elastic modulus of 32GPa, the tensile strength of 130MPa and the diameter of 32 GPa. The alkali water rate of the polycarboxylic acid high-efficiency water reducing agent is 25.5 percent. The purity of the quartz sand was 97%.

The preparation method of the graphene oxide reinforced iron tailing ceramsite concrete is the same as that in example 1.

Example 4

The graphene oxide reinforced iron tailing ceramsite concrete comprises the following raw materials in percentage by mass:

31.8 percent of coarse aggregate iron tailing ceramsite, 36.5 percent of quartz sand with fineness modulus of 1.13, 23.4 percent of cement-based gelling material and 8.3 percent of water; the graphene oxide accounts for 0.08 percent of the mass of the cement-based cementing material, and the polycarboxylic acid high-efficiency water reducing agent accounts for 2.0 percent of the mass of the cement-based cementing material. Wherein the barrel pressure strength of the iron tailing ceramsite is 5.43MPa, and the bulk density of the iron tailing ceramsite is 811kg/m³1756kg/m of apparent density³And the water absorption rate is 5.94 percent. The cement-based cementing material comprises ordinary portland cement with the strength grade of 42.5 and more than two grades of fly ash, wherein the median diameter (D50) of the portland cement is 11.02-15.10 mu m, and the activity of the fly ash is 68%. The specific surface area of the graphene oxide is 1000m²A single-layer carbon nano sheet with the diameter of 2.5nm, the length-width ratio of 3000, the elastic modulus of 32GPa, the tensile strength of 130MPa and the diameter of 32 GPa. The alkali water rate of the polycarboxylic acid high-efficiency water reducing agent is 25.5 percent. The purity of the quartz sand was 97%.

The preparation method of the graphene oxide reinforced iron tailing ceramsite concrete is the same as that in example 1.

Example 5

The graphene oxide reinforced iron tailing ceramsite concrete comprises the following raw materials in percentage by mass:

31.8 percent of coarse aggregate iron tailing ceramsite, 36.5 percent of quartz sand with fineness modulus of 1.13, 23.4 percent of cement-based cementing material and8.3 percent of water; the graphene oxide accounts for 0.10% of the mass of the cement-based cementing material, and the polycarboxylic acid high-efficiency water reducing agent accounts for 2.0% of the mass of the cement-based cementing material. Wherein the barrel pressure strength of the iron tailing ceramsite is 5.43MPa, and the bulk density of the iron tailing ceramsite is 811kg/m³1756kg/m of apparent density³And the water absorption rate is 5.94 percent. The cement-based cementing material comprises ordinary portland cement with the strength grade of 42.5 and more than two grades of fly ash, wherein the median diameter (D50) of the portland cement is 11.02-15.10 mu m, and the activity of the fly ash is 68%. The specific surface area of the graphene oxide is 1000m²A single-layer carbon nano sheet with the diameter of 2.5nm, the length-width ratio of 3000, the elastic modulus of 32GPa, the tensile strength of 130MPa and the diameter of 32 GPa. The alkali water rate of the polycarboxylic acid high-efficiency water reducing agent is 25.5 percent. The purity of the quartz sand was 97%.

The preparation method of the graphene oxide reinforced iron tailing ceramsite concrete is the same as that in example 1.

Example 6

The graphene oxide reinforced iron tailing ceramsite concrete comprises the following raw materials in percentage by mass:

31.0 percent of coarse aggregate iron tailing ceramsite, 38.2 percent of quartz sand with fineness modulus of 1.13, 22.5 percent of cement-based gelling material and 8.3 percent of water; the graphene oxide accounts for 0.02% of the mass of the cement-based cementing material, and the polycarboxylic acid high-efficiency water reducing agent accounts for 1.7% of the mass of the cement-based cementing material. Wherein the barrel pressure strength of the iron tailing ceramsite is 5.43MPa, and the bulk density of the iron tailing ceramsite is 811kg/m³1756kg/m of apparent density³And the water absorption rate is 5.94 percent. The cement-based cementing material comprises ordinary portland cement with the strength grade of 42.5 and more than two grades of fly ash, wherein the median diameter (D50) of the portland cement is 11.02-15.10 mu m, and the activity of the fly ash is 65%. The specific surface area of the graphene oxide is 1200m²A single-layer carbon nano-sheet with the length-width ratio of 4500, the elastic modulus of 35GPa, the tensile strength of 128MPa and the diameter of 0.95 nm. The alkali water rate of the polycarboxylic acid high-efficiency water reducing agent is 22.2 percent. The purity of the quartz sand was 99%.

The preparation method of the graphene oxide reinforced iron tailing ceramsite concrete comprises the following preparation steps:

step 1, mixing graphene oxide with 5.81% of water, stirring for 8 minutes at a stirring speed of 1000rpm, performing ultrasonic dispersion at a power of 1000w every 2.5 seconds for 45 minutes to obtain a graphene oxide aqueous solution.

And 2, mixing the graphene oxide aqueous solution with the polycarboxylic acid high-efficiency water reducing agent, and manually and slowly stirring for 8min to obtain the water aqua.

And 3, mixing the coarse aggregate, the quartz sand and the cement-based cementing material, firstly stirring for 5min at a low speed of 145 +/-5 r/min and 60 +/-5 r/min in a revolution by adopting a concrete stirrer, then stirring for 10min at a high speed of 275 +/-10 r/min in a rotation manner and 120 +/-10 r/min in a revolution manner, and finally stirring for 3min at a low speed of 145 +/-5 r/min in a rotation manner and 60 +/-5 r/min in a revolution manner to obtain a mixture.

And 4, mixing the aqueous agent and the mixture with 2.49 percent of water, firstly stirring for 5min at a low speed of 145 +/-5 r/min and 60 +/-5 r/min in a revolution by using a concrete stirrer, then stirring for 10min at a high speed of 275 +/-10 r/min in a rotation manner and 120 +/-10 r/min in a revolution manner, and finally stirring for 3min at a low speed of 145 +/-5 r/min in a rotation manner and 60 +/-5 r/min in a revolution manner to obtain the graphene oxide reinforced iron tailing ceramsite concrete.

Example 7

The graphene oxide reinforced iron tailing ceramsite concrete comprises the following raw materials in percentage by mass:

33.5 percent of coarse aggregate iron tailing ceramsite, 35.2 percent of quartz sand with fineness modulus of 1.13, 23 percent of cement-based gelling material and 8.3 percent of water; the graphene oxide accounts for 0.02% of the mass of the cement-based cementing material, and the polycarboxylic acid high-efficiency water reducing agent accounts for 1.9% of the mass of the cement-based cementing material. Wherein the barrel pressure strength of the iron tailing ceramsite is 5.43MPa, and the bulk density of the iron tailing ceramsite is 811kg/m³1756kg/m of apparent density³And the water absorption rate is 5.94 percent. The cement-based cementing material comprises ordinary portland cement with the strength grade of 42.5 and more than two grades of fly ash, wherein the median diameter (D50) of the portland cement is 11.02-15.10 mu m, and the activity of the fly ash is 70%. The specific surface area of the graphene oxide is 750m²A single-layer carbon nano-sheet with/g, length-width ratio of 2800, elastic modulus of 29GPa, tensile strength of 130MPa and diameter of 3.1 nm. The alkali water rate of the polycarboxylic acid high-efficiency water reducing agent is 28 percent. The purity of the quartz sand was 98%.

The preparation method of the graphene oxide reinforced iron tailing ceramsite concrete comprises the following preparation steps:

step 1, mixing graphene oxide with 5.81% of water, stirring for 5 minutes at a stirring speed of 800rpm, performing ultrasonic dispersion at a power of 1030w every 3 seconds for 60 minutes to obtain a graphene oxide aqueous solution.

And 2, mixing the graphene oxide aqueous solution with the polycarboxylic acid high-efficiency water reducing agent, and manually and slowly stirring for 5min to obtain the aqueous solution.

And 3, mixing the coarse aggregate, the quartz sand and the cement-based cementing material, firstly stirring for 5min at a low speed of 145 +/-5 r/min and 60 +/-5 r/min in a revolution by adopting a concrete stirrer, then stirring for 10min at a high speed of 275 +/-10 r/min in a rotation manner and 120 +/-10 r/min in a revolution manner, and finally stirring for 3min at a low speed of 145 +/-5 r/min in a rotation manner and 60 +/-5 r/min in a revolution manner to obtain a mixture.

And 4, mixing the aqueous agent and the mixture with 2.49 percent of water, firstly stirring for 5min at a low speed of 145 +/-5 r/min and 60 +/-5 r/min in a revolution by using a concrete stirrer, then stirring for 10min at a high speed of 275 +/-10 r/min in a rotation manner and 120 +/-10 r/min in a revolution manner, and finally stirring for 3min at a low speed of 145 +/-5 r/min in a rotation manner and 60 +/-5 r/min in a revolution manner to obtain the graphene oxide reinforced iron tailing ceramsite concrete.

Example 8

The graphene oxide reinforced iron tailing ceramsite concrete comprises the following raw materials in percentage by mass:

34.6 percent of coarse aggregate iron tailing ceramsite, 34.4 percent of quartz sand with fineness modulus of 1.13, 22.7 percent of cement-based gelling material and 8.3 percent of water; the graphene oxide accounts for 0.02% of the mass of the cement-based cementing material, and the polycarboxylic acid high-efficiency water reducing agent accounts for 2.1% of the mass of the cement-based cementing material. Wherein the barrel pressure strength of the iron tailing ceramsite is 5.43MPa, and the bulk density of the iron tailing ceramsite is 811kg/m³1756kg/m of apparent density³And the water absorption rate is 5.94 percent. The cement-based cementing material comprises ordinary portland cement with the strength grade of 42.5 and more than two grades of fly ash, wherein the median diameter (D50) of the portland cement is 11.02-15.10 mu m, and the activity of the fly ash is 68%. The specific surface area of the graphene oxide is 1300m²A single-layer carbon nano sheet with the length-width ratio of 4200, the elastic modulus of 30GPa, the tensile strength of 135MPa and the diameter of 0.85 nm. The alkali water rate of the polycarboxylic acid high-efficiency water reducing agent is 29 percent. The purity of the quartz sand was 97%.

The preparation method of the graphene oxide reinforced iron tailing ceramsite concrete comprises the following preparation steps:

step 1, mixing graphene oxide with 5.81% of water, stirring for 5.5 minutes at a stirring speed of 900rpm, performing ultrasonic dispersion at a power of 1010w every 1s for 80 minutes to obtain a graphene oxide aqueous solution.

And 2, mixing the graphene oxide aqueous solution with the polycarboxylic acid high-efficiency water reducing agent, and manually and slowly stirring for 6.5min to obtain the aqueous solution.

And 3, mixing the coarse aggregate, the quartz sand and the cement-based cementing material, firstly stirring for 5min at a low speed of 145 +/-5 r/min and 60 +/-5 r/min in a revolution by adopting a concrete stirrer, then stirring for 10min at a high speed of 275 +/-10 r/min in a rotation manner and 120 +/-10 r/min in a revolution manner, and finally stirring for 3min at a low speed of 145 +/-5 r/min in a rotation manner and 60 +/-5 r/min in a revolution manner to obtain a mixture.

And 4, mixing the aqueous agent and the mixture with 2.49 percent of water, firstly stirring for 5min at a low speed of 145 +/-5 r/min and 60 +/-5 r/min in a revolution by using a concrete stirrer, then stirring for 10min at a high speed of 275 +/-10 r/min in a rotation manner and 120 +/-10 r/min in a revolution manner, and finally stirring for 3min at a low speed of 145 +/-5 r/min in a rotation manner and 60 +/-5 r/min in a revolution manner to obtain the graphene oxide reinforced iron tailing ceramsite concrete.

Comparative example 1

The iron tailing ceramsite concrete comprises the following raw materials in percentage by mass:

31.8 percent of coarse aggregate iron tailing ceramsite, 36.5 percent of quartz sand with fineness modulus of 1.13, 23.4 percent of cement-based gelling material and 8.3 percent of water; the polycarboxylate superplasticizer accounts for 2.0 percent of the cement-based cementing material.

The preparation method of the graphene oxide reinforced iron tailing ceramsite concrete comprises the following preparation steps:

step 1, mixing coarse aggregate, quartz sand and cement-based cementing material, firstly stirring for 5min at low speed by adopting a concrete mixer after autorotation is 145 +/-5 r/min and revolution is 60 +/-5 r/min, then stirring for 10min at high speed by adopting autorotation 275 +/-10 r/min and revolution is 120 +/-10 r/min, and finally stirring for 3min at low speed by adopting autorotation of 145 +/-5 r/min and revolution is 60 +/-5 r/min to obtain a mixture.

And 2, mixing the mixture, water and the polycarboxylate superplasticizer, firstly stirring for 5min at a low speed of 145 +/-5 r/min and 60 +/-5 r/min in revolution by using a concrete stirrer, then stirring for 10min at a high speed of 275 +/-10 r/min in rotation and 120 +/-10 r/min in revolution, and finally stirring for 3min at a low speed of 145 +/-5 r/min in rotation and 60 +/-5 r/min in revolution to obtain the iron tailing ceramsite concrete.

Test of

Preparation of a test piece: according to the invention, the test piece is prepared, the size of the test piece is 100mm multiplied by 100mm, and the test piece is maintained for 28 days under the conditions that the temperature is 20 +/-2 ℃ and the relative humidity is 95 percent.

Respectively preparing the graphene oxide reinforced iron tailing ceramsite concrete of the embodiments 1-5 into test pieces 1-5 according to the preparation method; and preparing the iron tailing ceramsite concrete of the comparative example 1 into a test piece 0.

The compression strength, the splitting tensile strength, the elastic modulus and the fracture toughness of the test pieces 0-5 are respectively tested, and the test method specifically comprises the following steps:

the experimental method comprises the following steps:

compressive strength: refer to GB/T50081-2016 Standard test method for mechanical Properties of general concrete.

Splitting tensile strength: refer to GB/T50081-2016 Standard test method for mechanical Properties of general concrete.

Modulus of elasticity: reference is made to GB/T50081-2002 Standard for Experimental methods for mechanical Properties of ordinary concrete.

Runs 1-5: the test pieces 1 to 5 were measured for compressive strength, tensile strength at cleavage, elastic modulus, and fracture toughness according to the above-mentioned test methods, and the test results are shown in table 1.

Comparative experiment 1: the test results of the test piece 0 on the compression strength, the cleavage tensile strength, the elastic modulus and the test method are shown in table 1.

TABLE 1

As can be seen from table 1, the 28d compressive strength, the cleavage tensile strength and the elastic modulus of the graphene oxide reinforced iron tailing ceramsite concrete obtained in examples 1 to 5 are obviously higher than those of the iron tailing ceramsite concrete obtained in comparative example 1, which indicates that the compressive strength, the cleavage tensile strength and the elastic modulus of the iron tailing concrete can be significantly improved by compounding the graphene oxide with the iron tailing concrete in a proper amount, and the improvement ranges are 5.23% -14.82%, 23.07% -45.48% and 3.28% -8.27%, respectively. The graphene oxide nano concrete is mainly characterized in that the graphene oxide is compounded with concrete, cement hydration is promoted, the microstructure of the concrete is improved, and the graphene oxide nano concrete can prevent cracks from expanding on a micro nano scale, so that the performance of the concrete is effectively improved.

Although the present invention has been described in detail in this specification with reference to specific embodiments and illustrative embodiments, it will be apparent to those skilled in the art that modifications and improvements can be made thereto based on the present invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.