Multi-scale synergistic high-strength and high-conductivity concrete and preparation method thereof

Abstract

The invention discloses multi-scale synergistic high-strength and high-conductivity concrete and a preparation method thereof. The concrete is prepared from the following components in parts by weight: 200 to 300 parts of cement, 400 to 600 parts of fine aggregate, 800 to 1000 parts of coarse aggregate, 10 to 20 parts of CuNi coating composite carbon fibers, 5 to 10 parts of carbon nanotubes, 3 to 6 parts of graphene, 3 to 5 parts of a water reducing agent and 80 to 120 parts of water. The compressive strength of the concrete is effectively improved through the synergistic enhancement effect of the materials. The carbon nanotubes, the graphene and the CuNi coating composite carbon fibers are tightly combined with a cement matrix, the conductivity is enhanced, meanwhile, the overall strength of the concrete is effectively improved through the synergistic effect of the materials of different sizes, and the bearing requirements of various buildings are met. According to the invention, the requirements of special fields, such as electromagnetic shielding building, intelligent building structure health monitoring and the like, with harsh conductive performance requirements can be met.

Description

Technical Field

[0001] The present invention belongs to the technical field of building materials, and relates to a concrete and a preparation method thereof, and specifically to a multi-scale synergistic high-strength and high-conductivity concrete and a preparation method thereof. Background Art

[0002] With the development of modern construction technology, the requirements for concrete performance are becoming more and more diverse and stringent. In some special fields, such as electromagnetic shielding buildings, intelligent building structural health monitoring, and snow-melting and ice-removing roads, concrete is required to have high strength to meet the load-bearing requirements and good electrical conductivity to achieve the corresponding functions. However, traditional concrete often finds it difficult to achieve both high strength and high conductivity at the same time, which limits its application in these special fields. Summary of the invention

[0003] In view of the problem that traditional concrete is difficult to achieve both high strength and high conductivity at the same time, the present invention provides a multi-scale synergistic high-strength and high-conductivity concrete and a preparation method thereof. Through the rational combination of multi-scale materials, the synergistic improvement of concrete strength and conductivity is achieved.

[0004] The objective of the present invention is achieved through the following technical solutions:

[0005] A multi-scale synergistic high-strength and high-conductivity concrete comprises the following raw materials: 200-300 parts by weight of cement, 400-600 parts by weight of fine aggregate, 800-1000 parts by weight of coarse aggregate, 10-20 parts by weight of CuNi coated composite carbon fiber, 5-10 parts by weight of carbon nanotubes, 3-6 parts by weight of graphene, 3-5 parts by weight of water reducer, and 80-120 parts by weight of water, wherein: the cement is PO 42.5 ordinary Portland cement; the CuNi coated composite carbon fiber has a length of 3-6 mm and a diameter of 5-10 μm; the carbon nanotube has a tube diameter of 20-50 nm and a length of 10-30 μm.

[0006] A method for preparing the above-mentioned multi-scale synergistic high-strength and high-conductivity concrete comprises the following steps:

[0007] Step 1: Dry mix cement, fine aggregate and coarse aggregate in a mixer for 3 to 5 minutes to make them evenly mixed;

[0008] Step 2, adding the CuNi coated composite carbon fiber, carbon nanotubes and graphene into water, and ultrasonically dispersing for 15 to 20 minutes to form a uniform dispersion;

[0009] Step 3, adding the dispersion in step 2 to the dry material in step 1, and continue stirring for 5 to 8 minutes to allow the components to fully contact;

[0010] Step 4: Add water reducing agent and stir for 2 to 3 minutes to obtain a uniform concrete mixture;

[0011] Step 5: Pour the mixture into a mold, vibrate it into shape, and then cure it for 25 to 30 days under standard curing conditions to obtain a multi-scale synergistic high-strength and high-conductivity concrete product.

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] 1. The present invention constructs a multi-scale conductive network. Through a unique material combination, the CuNi coated composite carbon fiber forms a micron-scale conductive network in concrete, and the nano-carbon tubes fill its gaps, and together with graphene, construct a multi-scale conductive channel from nanometers to micrometers. In addition, the CuNi coated composite carbon fiber significantly improves the conductivity of the carbon fiber itself by embedding CuNi nanoparticles on the surface of the carbon fiber, further optimizing the overall conductive performance of the concrete. The present invention can meet the needs of special fields such as electromagnetic shielding buildings and intelligent building structural health monitoring that have strict requirements on conductive performance.

[0014] 2. The present invention effectively improves the compressive strength of concrete through the synergistic reinforcement between materials. Carbon nanotubes, graphene, and CuNi-coated composite carbon fibers with good mechanical properties are closely combined with the cement matrix. While enhancing the conductivity, the synergistic effect of these materials of different scales effectively improves the overall strength of concrete and meets the load-bearing requirements of various types of buildings.

[0015] 3. The preparation method of the present invention is simple and easy to implement, and is convenient for industrial production and promotion and application. The preparation method of concrete only requires simple dry mixing, ultrasonic dispersion, mixing, pouring, vibration and standard curing steps, without the need for complex equipment and processes, and is convenient for industrial large-scale production and promotion and application. The preparation process of CuNi coated composite carbon fiber is mature, and its preparation process uses common chemical reagents and can be completed under conventional temperature and time conditions, and each step is clear, easy to control and repeat, which provides a guarantee for the stable production of high-quality composite materials.

[0016] 4. The present invention significantly improves the conductivity and durability of conductive concrete. The CuNi coated composite carbon fiber not only improves the conductivity, but the CuNi coating on its surface also gives the material good durability, which helps to extend the service life of concrete products, reduce maintenance costs, and enable it to maintain good performance during long-term use. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a flow chart for the preparation of multi-scale synergistic high-strength and high-conductivity concrete.

[0018] Figure 2This is a flow chart for the preparation of CuNi coated composite carbon fibers. DETAILED DESCRIPTION

[0019] The technical solution of the present invention is further described below in conjunction with the accompanying drawings, but is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention should be included in the protection scope of the present invention.

[0020] The present invention provides a multi-scale synergistic high-strength and high-conductivity concrete, comprising the following raw materials: 200-300 parts by weight of cement, 400-600 parts by weight of fine aggregate, 800-1000 parts by weight of coarse aggregate, 10-20 parts by weight of CuNi coated composite carbon fiber, 5-10 parts by weight of nano carbon tubes, 3-6 parts by weight of graphene, 3-5 parts by weight of water reducer, and 80-120 parts by weight of water, wherein:

[0021] The cement is PO 42.5 ordinary Portland cement;

[0022] The CuNi coated composite carbon fiber has a length of 3 to 6 mm and a diameter of 5 to 10 μm, and forms a micrometer-scale conductive network in the concrete;

[0023] The nano carbon tubes have a diameter of 20 to 50 nm and a length of 10 to 30 μm. They can fill the gaps in the carbon fiber network and build a multi-scale conductive channel from nanometers to micrometers together with graphene, greatly improving the conductivity of concrete. At the same time, these nano and micron-scale materials are closely combined with the cement matrix. On the basis of enhancing conductivity, they synergistically improve the overall strength of concrete through their good mechanical properties.

[0024] The CuNi coated composite carbon fiber improves the conductivity of the carbon fiber by embedding CuNi nanoparticles into the surface of the carbon fiber, and has good durability. Figure 2 As shown, the specific preparation steps are as follows:

[0025] Step (1) 1.7 g of carbon fiber was ultrasonically treated in a mixture of ethanol and water for 30 minutes, then washed several times with deionized (DI) water and anhydrous ethanol, and the cleaned carbon fiber was dried in a vacuum at 100° C. for further use;

[0026] Step (2) 0.5 mmol of Ni(NO 3 ) 2 6H 2 O, 0.5 mmol Cu(NO 3 ) 2 ·3H 2and 60 mmol of urea were dissolved in 1 L of deionized water, 1.7 g of the carbon fiber purified in step (1) was added to form a uniform suspension, and then heated at 100 ° C for 12 h, and the obtained brown carbon fiber composite material was dried in an oven at 100 ° C;

[0027] Step (3) The sample obtained in step 2 is 2 The CuNi coated composite carbon fiber was carbonized at 900 °C for 1 h in an ambient environment.

[0028] A method for preparing the above-mentioned multi-scale synergistic high-strength and high-conductivity concrete, such as Figure 1 As shown, the following steps are included:

[0029] Step 1: Dry mix cement, fine aggregate and coarse aggregate in a mixer for 3 to 5 minutes to make them evenly mixed;

[0030] Step 2, adding the CuNi coated composite carbon fiber, carbon nanotubes and graphene into water, and ultrasonically dispersing for 15 to 20 minutes to form a uniform dispersion;

[0031] Step 3, adding the dispersion in step 2 to the dry material in step 1, and continue stirring for 5 to 8 minutes to allow the components to fully contact;

[0032] Step 4: Add water reducing agent and stir for 2 to 3 minutes to obtain a uniform concrete mixture;

[0033] Step 5: Pour the mixture into a mold, vibrate it into shape, and then cure it for 25 to 30 days under standard curing conditions to obtain a multi-scale synergistic high-strength and high-conductivity concrete product.

[0034] The present invention solves the following technical problems:

[0035] 1. Solve the problem of internal structural defects caused by the addition of conductive materials in traditional concrete: Adding conductive materials in the traditional way can easily form too many pores and defects in the concrete, reducing the integrity and stability of the material. The present invention aims to avoid this problem and ensure the good condition of the internal structure of the concrete.

[0036] 2. It overcomes the problem of traditional concrete that the bonding between cement paste and aggregate decreases due to improved conductivity: conventional means of improving concrete conductivity will weaken the bonding between cement paste and aggregate, affecting the strength and durability of concrete. The present invention solves this drawback through a unique material combination.

[0037] 3. It solves the limitation problem of single performance improvement when traditional concrete is used in special fields: When improving the performance of traditional concrete in special fields, it often only focuses on unilateral improvement of strength or conductivity, and it is difficult to comprehensively meet multiple performance requirements. The present invention can achieve coordinated optimization of multiple performances and break through the limitation of single performance improvement.

[0038] Embodiment 1:

[0039] Take 250 parts by weight of cement, 500 parts by weight of fine aggregate, 900 parts by weight of coarse aggregate, 15 parts by weight of CuNi coated composite carbon fiber, 8 parts by weight of carbon nanotubes, 5 parts by weight of graphene, 4 parts by weight of water reducer, and 100 parts by weight of water. Among them, the length of the CuNi coated composite carbon fiber is 5 mm, the diameter is 5 to 10 μm, the diameter of the carbon nanotube is 20 to 30 nm, and the length is 10 to 30 μm. The specific preparation method is as follows:

[0040] Step 1: Dry mix cement, fine aggregate and coarse aggregate in a mixer for 5 minutes to make them evenly mixed;

[0041] Step 2, adding the CuNi coated composite carbon fiber, carbon nanotubes and graphene into water, and ultrasonically dispersing for 20 minutes to form a uniform dispersion;

[0042] Step 3, add the dispersion in step 2 to the dry material in step 1, and continue stirring for 6 minutes to allow the components to fully contact;

[0043] Step 4: Add water reducing agent and stir for another 3 minutes to obtain a uniform concrete mixture;

[0044] Step 5: Pour the mixture into a mold, vibrate it into shape, and then cure it for 28 days under standard curing conditions to obtain a multi-scale synergistic high-strength and high-conductivity concrete product.

[0045] The concrete obtained in this example has a 28-day compressive strength of more than 60 MPa and an electrical conductivity of 10 -1 S / m, meeting the requirements of high strength and high conductivity.

[0046] Embodiment 2:

[0047] The difference between this embodiment and embodiment 1 is that the raw material ratio is adjusted to 280 parts by weight of cement, 550 parts by weight of fine aggregate, 850 parts by weight of coarse aggregate, 18 parts by weight of CuNi coated composite carbon fiber, 6 parts by weight of carbon nanotubes, 4 parts by weight of graphene, 3.5 parts by weight of water reducer, and 90 parts by weight of water. Among them, the length of the CuNi coated composite carbon fiber is 3mm, the diameter is 5-10μm, the diameter of the carbon nanotube is 40-50nm, and the length is 10-30μm. The concrete prepared in this embodiment has the same excellent performance, and the formula can be flexibly adjusted according to actual needs to adapt to different application scenarios.

[0048] Embodiment 3:

[0049] The difference between this embodiment and embodiment 1 is that the raw material ratio is adjusted to 220 parts by weight of cement, 450 parts by weight of fine aggregate, 950 parts by weight of coarse aggregate, 12 parts by weight of CuNi coated composite carbon fiber, 7 parts by weight of carbon nanotubes, 6 parts by weight of graphene, 5.5 parts by weight of water reducer, and 110 parts by weight of water. Among them, the length of the CuNi coated composite carbon fiber is 6 mm, the diameter is 5 to 10 μm, the diameter of the carbon nanotube is 30 to 40 nm, and the length is 10 to 30 μm. The concrete prepared in this embodiment has the same excellent performance, and the formula can be flexibly adjusted according to actual needs to adapt to different application scenarios.

Claims

1. A multi-scale synergistic high-strength and high-conductivity concrete, characterized in that The concrete comprises the following raw materials: 200-300 parts by weight of cement, 400-600 parts by weight of fine aggregate, 800-1000 parts by weight of coarse aggregate, 10-20 parts by weight of CuNi coated composite carbon fiber, 5-10 parts by weight of nano carbon tubes, 3-6 parts by weight of graphene, 3-5 parts by weight of water reducer and 80-120 parts by weight of water.

2. The multi-scale synergistic high-strength and high-conductivity concrete according to claim 1 is characterized in that The cement is P.O42.5 ordinary Portland cement.

3. The multi-scale synergistic high-strength and high-conductivity concrete according to claim 1 is characterized in that The CuNi coating composite carbon fiber has a length of 3 to 6 mm and a diameter of 5 to 10 μm.

4. The multi-scale synergistic high-strength and high-conductivity concrete according to claim 1, characterized in that The diameter of the nano carbon tube is 20-50 nm, and the length is 10-30 μm.

5. The multi-scale synergistic high-strength and high-conductivity concrete according to claim 1 is characterized in that The concrete includes the following raw materials: 250 parts by weight of cement, 500 parts by weight of fine aggregate, 900 parts by weight of coarse aggregate, 15 parts by weight of CuNi coated composite carbon fiber, 8 parts by weight of carbon nanotubes, 5 parts by weight of graphene, 4 parts by weight of water reducer, and 100 parts by weight of water.

6. The multi-scale synergistic high-strength and high-conductivity concrete according to claim 1, characterized in that The concrete includes the following raw materials: 280 parts by weight of cement, 550 parts by weight of fine aggregate, 850 parts by weight of coarse aggregate, 18 parts by weight of CuNi coated composite carbon fiber, 6 parts by weight of carbon nanotubes, 4 parts by weight of graphene, 3.5 parts by weight of water reducer, and 90 parts by weight of water.

7. The multi-scale synergistic high-strength and high-conductivity concrete according to claim 1, characterized in that The concrete includes the following raw materials: 220 parts by weight of cement, 450 parts by weight of fine aggregate, 950 parts by weight of coarse aggregate, 12 parts by weight of CuNi coated composite carbon fiber, 7 parts by weight of carbon nanotubes, 6 parts by weight of graphene, 5.5 parts by weight of water reducer, and 110 parts by weight of water.

8. A method for preparing the multi-scale synergistic high-strength and high-conductivity concrete according to any one of claims 1 to 7, characterized in that The method comprises the following steps: Step 1: Dry mix cement, fine aggregate and coarse aggregate in a mixer for 3 to 5 minutes to make them evenly mixed; Step 2, adding the CuNi coated composite carbon fiber, carbon nanotubes and graphene into water, and ultrasonically dispersing for 15 to 20 minutes to form a uniform dispersion; Step 3, adding the dispersion in step 2 to the dry material in step 1, and continue stirring for 5 to 8 minutes to allow the components to fully contact; Step 4: Add water reducing agent and stir for 2 to 3 minutes to obtain a uniform concrete mixture; Step 5: pour the mixture into a mold, vibrate it into shape, and then cure it under standard curing conditions for 25 to 30 days to obtain a multi-scale synergistic high-strength and high-conductivity concrete product.

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