Multi-density grade pumped radiation shielding concrete and method of making

Abstract

The application relates to the technical field of building materials, and particularly discloses a multi-density-grade pumping radiation-proof concrete and a preparation method thereof. The multi-density-grade pumping radiation-proof concrete comprises the following raw materials: cement, fly ash, lead-zinc tailings, heavy spar, polyethylene, boron carbide, basalt fiber, water and a water reducing agent. The preparation method of the multi-density-grade pumping radiation-proof concrete comprises the following steps: S1, mixing and stirring cement, fly ash, lead-zinc tailings, heavy spar, basalt fiber and a water reducing agent to obtain a mixture; S2, mixing and stirring polyethylene and boron carbide to obtain a polyethylene-boron carbide mixture; and S3, mixing and stirring the mixture obtained in the step S1, the polyethylene-boron carbide mixture obtained in the step S2 and water to obtain the multi-density-grade pumping radiation-proof concrete.

Description

Technical Field

[0001] This application relates to the field of building materials technology, and in particular to a multi-density grade pumpable radiation-proof concrete and its preparation method. Background Technology

[0002] With the rapid development of nuclear technology in my country, it has been integrated into all aspects of people's lives. Besides the well-known applications of nuclear weapons and nuclear power, the nuclear industry also has wide-ranging applications in light industry. Nuclear reactors and other radiation sources inevitably release various energetic rays during operation, which can harm the environment and human health. Neutron radiation, as well as X-rays and gamma rays, are the main components of nuclear reactor radiation, making shielding and protection against these two types of rays particularly important.

[0003] Radiation-shielding concrete, also known as shielding concrete, is currently the most widely used and economical nuclear radiation protection material. Compared with metals and other protective materials, it has advantages such as a wide availability of raw materials, ease of construction, and low manufacturing costs. It also has a wide range of applications, including nuclear industry facilities, medical facilities, and research institutions. Radiation-shielding concrete is generally formulated using barite and various iron ores with high apparent density as aggregates. Its ability to shield against radiation is improved by increasing apparent density and compactness. However, the range of apparent densities of available barite is limited, making it difficult to meet engineering design requirements, and its radiation resistance performance is also limited. Summary of the Invention

[0004] In order to solve at least one of the above-mentioned technical problems and develop a type of concrete with high apparent density and high radiation resistance, this application provides a multi-density grade pumpable radiation-resistant concrete and its preparation method.

[0005] On the one hand, the multi-density grade pumpable radiation-proof concrete provided in this application comprises the following components by weight: 230-260 parts cement, 70-100 parts fly ash, 500-700 parts lead-zinc tailings, 800-1120 parts barite, 400-500 parts polyethylene, 50-100 parts boron carbide, 80-100 parts basalt fiber, 145-180 parts water, and 2-10 parts water-reducing agent.

[0006] By adopting the above technical solutions, this application uses barite and lead-zinc tailings as aggregates, cement as the main gelling material, and the addition of fly ash can improve the fluidity, cohesiveness and water retention of concrete mix, making the concrete mix easy to pump and cast; the addition of polyethylene and boron carbide can absorb neutrons and reduce their penetrating power, thereby effectively reducing and shielding neutron radiation, exhibiting good radiation resistance and effectively improving the radiation protection performance of concrete; the addition of basalt fiber has advantages such as high strength, high heat resistance and good chemical stability, which can enhance the strength and stability of concrete.

[0007] Optionally, the weight ratio of lead-zinc tailings to barite is (0.5-0.75):1.

[0008] Optionally, barite includes barite crushed stone and barite sand, wherein the weight ratio of barite crushed stone to barite sand is (1-2):1.

[0009] Optionally, barite crushed stone includes large barite crushed stone and small barite crushed stone. The large barite crushed stone has a particle size of 10-20mm and the small barite crushed stone has a particle size of 5-10mm.

[0010] Optionally, the weight ratio of large barite fragments to small barite fragments is (1.5-2.5):1.

[0011] By adopting the above technical solution, this application uses lead-zinc tailings and barite in combination, and selects barite sand and barite crushed stone of different particle sizes. This can adjust the density and strength of concrete to meet the needs of radiation-proof concrete with different apparent densities. Moreover, lead-zinc tailings contain many heavy metal elements, especially Pb, which are abundant and inexpensive. Using lead-zinc tailings can fully recycle and utilize them, effectively solving the pollution problem caused by waste accumulation.

[0012] Optionally, the polyethylene is ultra-high molecular weight polyethylene.

[0013] Optionally, the boron carbide particle size is 5-25 μm.

[0014] Optionally, the weight ratio of polyethylene to boron carbide is (5-7):1.

[0015] By adopting the above technical solution, this application uses polyethylene and boron carbide to effectively reduce and shield neutron radiation, exhibiting good radiation resistance and effectively improving the radiation protection performance of concrete.

[0016] Optionally, the water-reducing agent is a polycarboxylate superplasticizer.

[0017] Secondly, this application provides a method for preparing the above-mentioned multi-density grade pumped radiation-shielding concrete, including the following steps:

[0018] S1. Mix cement, fly ash, lead-zinc tailings, barite, and water-reducing agent for 5-15 minutes at a speed of 200-300 rpm to obtain a mixture.

[0019] S2. Mix polyethylene and boron carbide for 5-15 minutes at a speed of 200-300 rpm to obtain a polyethylene-boron carbide mixture.

[0020] S3. Mix the mixture obtained in step S1, the polyethylene-boron carbide mixture obtained in step S2, and water. Stir for 20-30 minutes at a stirring speed of 400-500 rpm to obtain the multi-density grade pumpable radiation-proof concrete, which can effectively block electromagnetic radiation such as X-rays, gamma rays, and neutron radiation.

[0021] By adopting the above technical solution, the preparation method of this application is simple and easy to apply in engineering. The multi-density grade pumpable radiation shielding concrete can effectively block electromagnetic radiation such as X-rays, gamma rays and neutron radiation.

[0022] In summary, the present invention has at least one of the following beneficial technical effects:

[0023] 1. By adopting the above technical solution, this application uses barite and lead-zinc tailings as aggregates, cement as the main gelling material, and the addition of fly ash can improve the fluidity, cohesiveness and water retention of concrete mix, making the concrete mix easy to pump and cast; the addition of polyethylene and boron carbide can absorb neutrons and reduce the penetrating power of neutrons, thereby effectively reducing and shielding neutron radiation, and has good radiation resistance performance, which can effectively improve the radiation protection performance of concrete; the addition of basalt fiber has the advantages of high strength, high heat resistance and good chemical stability, which can enhance the strength and stability of concrete.

[0024] 2. This application uses lead-zinc tailings and barite in combination, and selects barite sand and barite crushed stone of different particle sizes. This can adjust the density and strength of the concrete to meet the needs of radiation-proof concrete with different apparent densities. In addition, lead-zinc tailings contain many heavy metal elements, especially Pb, which are abundant and inexpensive. Using lead-zinc tailings can fully recycle and utilize them, effectively solving the pollution problem caused by waste accumulation.

[0025] 3. The preparation method of this application is simple and easy to apply in engineering. The multi-density grade pumpable radiation shielding concrete produced can effectively block electromagnetic radiation such as X-rays, gamma rays and neutron radiation. Detailed Implementation

[0026] The present application will be further described in detail below with reference to the embodiments.

[0027] This application designs a multi-density grade pumpable radiation-proof concrete, which, by weight, comprises the following components: 230-260 parts cement, 70-100 parts fly ash, 550-650 parts lead-zinc tailings, 800-1000 parts barite crushed stone, 400-500 parts polyethylene, 50-100 parts boron carbide, 80-100 parts basalt fiber, 145-180 parts water, and 2-10 parts water-reducing agent.

[0028] The multi-density grade pumpable radiation-shielding concrete of this application is prepared by the following method, including the following steps:

[0029] S1. Mix cement, fly ash, lead-zinc tailings, barite, basalt fiber, and water-reducing agent for 5-15 minutes at a speed of 200-300 rpm to obtain a mixture.

[0030] S2. Mix polyethylene and boron carbide for 5-15 minutes at a speed of 200-300 rpm to obtain a polyethylene-boron carbide mixture.

[0031] S3. Mix the mixture obtained in step S1, the polyethylene-boron carbide mixture obtained in step S2, and water. Stir for 20-30 minutes and at a speed of 400-500 rpm to obtain the multi-density grade pumpable radiation-proof concrete. Specific Implementation

[0033] The cement is grade 42.5 ordinary Portland cement;

[0034] The fly ash is classified as Class I fly ash.

[0035] The polyethylene is ultra-high molecular weight polyethylene, with a molecular weight of 4-5 million.

[0036] Boron carbide: CAS No.: 12069-32-8;

[0037] Basalt fiber: Dazhou Changshi Technology Co., Ltd.;

[0038] Water-reducing agent: Polycarboxylate superplasticizer, Shandong Tianfeng Chemical Technology Co., Ltd.

[0039] Example 1

[0040] A multi-density grade pumpable radiation-shielding concrete, by weight, comprises the following components: 230 parts cement, 70 parts fly ash, 550 parts lead-zinc tailings, 800 parts barite, 400 parts polyethylene, 50 parts boron carbide, 80 parts basalt fiber, 145 parts water, and 2 parts water-reducing agent; the barite includes barite crushed stone and barite sand in a weight ratio of 1:1; the barite crushed stone includes large barite crushed stone with a particle size of 10-20 mm and small barite crushed stone with a particle size of 5-10 mm, with a weight ratio of 1.5:1; the boron carbide has a particle size of 25 μm.

[0041] A method for preparing multi-density grade pumpable radiation-shielding concrete includes the following steps:

[0042] S1. Mix cement, fly ash, lead-zinc tailings, barite crushed stone, basalt fiber, and water-reducing agent for 10 minutes at a speed of 250 rpm to obtain a mixture.

[0043] S2. Mix polyethylene and boron carbide for 10 minutes at a speed of 300 rpm to obtain a polyethylene-boron carbide mixture.

[0044] S3. Mix the mixture obtained in step S1, the polyethylene-boron carbide mixture obtained in step S2, and water. Stir for 30 minutes at a stirring speed of 480 rpm to obtain the multi-density grade pumpable radiation-proof concrete.

[0045] The difference between Examples 2-5 and Example 1 lies in the different weight proportions of raw materials used in preparing multi-density grade pumped radiation-shielding concrete. The differences are shown in Table 1.

[0046] Table 1 shows the differences between Examples 2-5 and Example 1. (See Table 1 for details.)

[0047]

[0048] Comparative Example 1

[0049] The difference between this comparative example and Example 1 is that no lead-zinc tailings were added when preparing multi-density grade pumped radiation-proof concrete in this comparative example.

[0050] Comparative Example 2

[0051] The difference between this comparative example and Example 1 is that boron carbide was not added when preparing multi-density grade pumped radiation-proof concrete in this comparative example.

[0052] Comparative Example 3

[0053] The difference between this comparative example and Example 1 is that basalt fiber was not added when preparing multi-density grade pumped radiation-proof concrete in this comparative example.

[0054] Experimental testing

[0055] Apparent density, slump / spread: GB / T 50080-2016 Standard for Test Methods of Performance of Ordinary Concrete Mixtures; 28-day compressive strength: GB / T 50081-2019 Standard for Test Methods of Physical and Mechanical Properties of Concrete.

[0056] Radiation protection: The concrete prepared in the examples and comparative examples was used to make a wall with a thickness of 250 mm. A radiation source with a radiation rate of 120 Sv / h was placed on one side of the wall, and then a radiation monitoring instrument was used to detect the radiation on the other side of the wall.

[0057] This experiment will test the apparent density, slump / spread, 28-day compressive strength, and radiation protection performance of the multi-density grade pumped radiation-shielding concrete prepared by Examples 1-5 and Comparative Examples 1-3.

[0058] The test results of this experiment are shown in Table 2.

[0059] Table 2 - Test Results of Examples 1-5 and Comparative Examples 1-3

[0060]

[0061] Results analysis:

[0062] As can be seen from Examples 1-5, Comparative Examples 1-3, and Tables 1 and 2, the multi-density grade pumpable radiation-proof concrete prepared by this application has a higher apparent density, better compressive strength and radiation protection effect, and better workability. Long-distance pumping construction can be achieved using ordinary concrete pumping equipment.

[0063] Comparing Example 1 with Comparative Examples 1 and 2, it can be seen that adding lead-zinc tailings and boron carbide can increase the apparent density of concrete and improve its radiation protection performance.

[0064] Comparing Example 1 and Comparative Example 3, it can be seen that adding basalt fiber can effectively enhance the compressive strength of concrete.

[0065] Examples 6-8

[0066] Example 6

[0067] The difference between Example 6 and Example 3 is that the total weight of lead-zinc tailings and barite is 1560 parts. The weight ratio of lead-zinc tailings to barite is 0.5:1.

[0068] Example 7

[0069] The difference between Example 7 and Example 3 is that the total weight of lead-zinc tailings and barite is 1560 parts. The weight ratio of lead-zinc tailings to barite is 0.68:1.

[0070] Example 8

[0071] The difference between Example 8 and Example 3 is that the total weight of lead-zinc tailings and barite is 1560 parts. The weight ratio of lead-zinc tailings to barite is 0.75:1.

[0072] The experimental test results of Examples 6 to 8 are shown in Table 3.

[0073] Table 3 - Experimental test results of Examples 6 to 8 (see table)

[0074]

[0075] Results analysis:

[0076] As can be seen from Examples 6-8, Example 3 and Table 3, when the weight ratio of lead-zinc tailings to barite is limited, the concrete produced has better performance in various aspects when the weight ratio of lead-zinc tailings to barite is in the range of (0.5-0.75):1.

[0077] Examples 9-11

[0078] Example 9

[0079] The difference between Example 9 and Example 7 is that the weight ratio of barite crushed stone to barite sand is 1.4:1.

[0080] Example 10

[0081] The difference between Example 10 and Example 7 is that the weight ratio of barite crushed stone to barite sand is 1.8:1.

[0082] Example 11

[0083] The difference between Example 11 and Example 7 is that the weight ratio of barite crushed stone to barite sand is 2:1.

[0084] The experimental test results of Examples 9 to 11 are shown in Table 4.

[0085] Table 4 - Experimental test results of Examples 9 to 11 (see table)

[0086]

[0087]

[0088] Results analysis:

[0089] As can be seen from Examples 9-11, Example 7 and Table 4, when the weight ratio of barite crushed stone to barite sand is limited, the concrete produced has better performance in various aspects when the weight ratio of barite crushed stone to barite sand is in the range of (1-2):1.

[0090] Examples 12-14

[0091] Example 12

[0092] The difference between Example 12 and Example 10 is that the weight ratio of large barite fragments to small barite fragments is 1.8:1.

[0093] Example 13

[0094] The difference between Example 13 and Example 10 is that the weight ratio of large barite fragments to small barite fragments is 2.3:1.

[0095] Example 14

[0096] The difference between Example 14 and Example 10 is that the weight ratio of large barite fragments to small barite fragments is 2.5:1.

[0097] The experimental test results of Examples 12-14 are shown in Table 5.

[0098] Table 5 - Experimental test results of Examples 12-14 (see table)

[0099]

[0100] Results analysis:

[0101] As can be seen from Examples 12-14, Example 10 and Table 5, when the weight ratio of large barite crushed stone to small barite crushed stone is limited, the concrete produced has better performance when the weight ratio of large barite crushed stone to small barite crushed stone is in the range of (1.5-2.5):1.

[0102] Examples 15-17

[0103] Example 15

[0104] The difference between Example 15 and Example 13 is that the boron carbide particle size is 20 μm.

[0105] Example 16

[0106] The difference between Example 16 and Example 13 is that the boron carbide particle size is 13 μm.

[0107] Example 17

[0108] The difference between Example 17 and Example 13 is that the boron carbide particle size is 5 μm.

[0109] The experimental test results of Examples 15-17 are shown in Table 6.

[0110] Table 6 - Experimental test results of Examples 15-17 (see table)

[0111]

[0112] Results analysis:

[0113] As can be seen from Examples 15-17, Example 13 and Table 6, when the boron carbide particle size is limited to the range of 5-25 μm, the concrete produced has better performance.

[0114] Examples 18-20

[0115] Example 18

[0116] The difference between Example 18 and Example 17 is that the total weight of polyethylene and boron carbide is 540 parts, wherein the weight ratio of polyethylene to boron carbide is 5:1.

[0117] Example 19

[0118] The difference between Example 19 and Example 17 is that the total weight of polyethylene and boron carbide is 540 parts, wherein the weight ratio of polyethylene to boron carbide is 6.3:1.

[0119] Example 20

[0120] The difference between Example 20 and Example 17 is that the total weight of polyethylene and boron carbide is 540 parts, wherein the weight ratio of polyethylene to boron carbide is 7:1.

[0121] The experimental test results of Examples 18-20 are shown in Table 7.

[0122] Table 7 - Experimental test results of Examples 18-20 (see table)

[0123]

[0124]

[0125] Results analysis:

[0126] As can be seen from Examples 18-20, Example 17 and Table 7, when the weight ratio of polyethylene to boron carbide is limited, the concrete produced has better properties when the weight ratio of polyethylene to boron carbide is in the range of (5-7):1.

[0127] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A multi-density grade pumpable radiation-shielding concrete, characterized in that, By weight, it includes the following components: 230-260 parts cement, 70-100 parts fly ash, 500-700 parts lead-zinc tailings, 800-1120 parts barite, 400-500 parts polyethylene, 50-100 parts boron carbide, 80-100 parts basalt fiber, 145-180 parts water, and 2-10 parts water-reducing agent. The barite comprises barite crushed stone and barite sand, wherein the weight ratio of the barite crushed stone to the barite sand is (1-2):1; The barite crushed stone includes large barite crushed stone and small barite crushed stone. The large barite crushed stone has a particle size of 10-20 mm and the small barite crushed stone has a particle size of 5-10 mm. The weight ratio of the large barite crushed stone to the small barite crushed stone is (1.5-2.5):1; The boron carbide particle size is 5-25 μm; The weight ratio of polyethylene to boron carbide is (5-7):

1.

2. The multi-density grade pumpable radiation-shielding concrete according to claim 1, characterized in that, The weight ratio of lead-zinc tailings to barite is (0.5-0.75):

1.

3. The multi-density grade pumpable radiation-shielding concrete according to claim 1, characterized in that, The polyethylene is ultra-high molecular weight polyethylene.

4. The multi-density grade pumpable radiation-shielding concrete according to claim 1, characterized in that, The water-reducing agent is a polycarboxylate superplasticizer.

5. A method for preparing multi-density grade pumped radiation-shielding concrete as described in claim 1, characterized in that, Includes the following steps: S1. Mix cement, fly ash, lead-zinc tailings, barite, basalt fiber, and water-reducing agent for 5-15 minutes at a speed of 200-300 rpm to obtain a mixture. S2. Mix polyethylene and boron carbide for 5-15 minutes at a speed of 200-300 rpm to obtain a polyethylene-boron carbide mixture. S3. Mix the mixture obtained in step S1, the polyethylene-boron carbide mixture obtained in step S2, and water. Stir for 20-30 minutes and at a speed of 400-500 rpm to obtain the multi-density grade pumpable radiation-proof concrete.

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