High-performance concrete capable of preventing gamma-ray radiation and preparation method of high-performance concrete

Abstract

The invention discloses high-performance concrete capable of preventing gamma-ray radiation and a preparation method of the high-performance concrete, and belongs to the technical field of building materials. Comprising 1000-2400 kg / m < 3 > of gamma-ray shielding aggregate, less than or equal to 95 kg / m < 3 > of gamma-ray shielding gelling components and 200-260 kg / m < 3 > of steel fibers. The gamma-ray shielding gelling component is one or a mixture of two of lead powder and barite powder; the gamma-ray shielding aggregate is one or a mixture of more of selected magnetite aggregate, barite aggregate, hematite aggregate and high-titanium heavy slag sand; the high-performance concrete has good working performance, mechanical performance, gamma-ray shielding performance, dynamic impact performance and durability, the gamma-ray shielding performance of a UHPC material can be effectively improved while excellent dynamic / static mechanical performance is guaranteed, and the high-performance concrete has important actual popularization value.

Description

Technical Field

[0001] This invention belongs to the field of building materials technology, specifically a high-performance concrete that protects against gamma-ray radiation and its preparation method. Background Technology

[0002] The rapid development of nuclear technology has driven the development of fields such as energy, medicine and military. However, the process of nuclear fission and the use of radioactive nuclides will generate a large number of secondary particles and secondary rays. Long-term exposure to these particles and rays can cause immune deficiencies in the human body and increase the risk of disease and death.

[0003] Concrete, as the mainstream building material worldwide, is the most widely used and economically superior radiation shielding material due to its advantages such as abundant raw materials, low cost, controllable shape and size, and convenient construction. However, currently in-service concrete shielding structures have a high water-cement ratio and relatively insufficient mechanical properties. Ultra-high performance concrete (UHPC) materials possess characteristics such as high damage tolerance, high fracture toughness, ultra-high strength, and excellent durability. Using UHPC materials to prepare radiation shielding materials can not only improve the mechanical properties of the material but also enhance its durability, thereby extending its lifespan.

[0004] Gamma rays interact with matter in numerous ways, with three being the most representative: the photoelectric effect, Compton scattering, and the pair production effect. The interaction between gamma rays and matter depends not only on the energy of the incident photon but also on the atomic number (Z) of the matter. Within the dominant energy ranges of the photoelectric effect, Compton scattering, and pair production effect, their interaction cross-sections are related to Z, respectively. 4-5 Z, Z 2 The effect is directly proportional. Therefore, it can be concluded that materials containing elements with high atomic numbers are beneficial for shielding gamma rays. Based on this theory, the gamma-ray shielding performance of UHPC materials can be improved by adding aggregates and cementitious components containing high atomic numbers. However, existing gamma-ray resistant concrete still has the following technical problems: I. Insufficient mechanical and durability properties The current concrete shielding structures have a high water-cement ratio, which directly results in relatively poor mechanical properties, making them unable to meet the requirements of high-load and high-damage-risk scenarios. At the same time, an excessively high water-cement ratio reduces the density of concrete, thereby affecting its durability. Under long-term service or complex environments, problems such as cracking and erosion are likely to occur, shortening the service life of the shielding structure and making it difficult to guarantee the long-term stability of radiation protection.

[0005] II. Limited gamma-ray shielding performance The aggregates and cementitious components of existing ordinary concrete are mostly conventional materials with low atomic numbers (Z). However, the shielding effect of gamma rays is closely related to the atomic number of the material; the interaction cross-sections of the photoelectric effect, Compton scattering, and pair production are respectively related to Z. 4-5 Z, Z 2 Proportional to this, the low atomic number array composition makes concrete weak in its interaction with gamma rays, making it difficult to achieve higher protection standards for shielding effectiveness and failing to meet the needs of scenarios with high gamma ray shielding requirements.

[0006] III. Lack of dynamic impact performance Existing concrete shielding structures are not optimized for dynamic impact scenarios and lack sufficient impact resistance. In nuclear-related scenarios, they may face dynamic conditions such as accident impacts and external loads. Ordinary concrete has insufficient fracture toughness and damage tolerance, making it prone to structural damage after impact. Once the shielding structure fails, the risk of radiation leakage will increase significantly.

[0007] IV. Poor multi-performance synergy Existing concrete cannot simultaneously achieve optimal performance in terms of workability, mechanical properties, gamma-ray shielding, dynamic impact resistance, and durability. While ordinary concrete has advantages such as readily available raw materials and low cost, improving gamma-ray shielding performance often comes at the expense of mechanical or workability properties. Furthermore, concrete materials that have not undergone targeted optimization cannot achieve a balanced improvement in multiple properties, making them unsuitable for radiation protection scenarios with high comprehensive performance requirements. Summary of the Invention

[0008] This invention overcomes the shortcomings of existing technologies and proposes a high-performance concrete that protects against gamma-ray radiation and its preparation method. This invention is achieved through the following technical solution: A high-performance concrete for shielding against gamma-ray radiation, comprising cementitious materials and gamma-ray shielding aggregates of 1000~2400 kg / m³. 3 γ-ray shielding gel component ≤95 kg / m 3 200~260 kg / m² of steel fiber 3 The gamma-ray shielding cementitious component is one or a mixture of two of lead powder and barite powder; the gamma-ray shielding aggregate is one or a mixture of several of selected magnetite aggregate, barite aggregate, hematite aggregate, and high-titanium heavy ore slag sand.

[0009] Preferably, it also includes ≤15 kg / m 3 CaCO3 whiskers.

[0010] Preferably, the apparent density of the CaCO3 whiskers is 2800 kg / m³. 3It has a diameter of 0.5~2 μm, a length of 10~20 μm, an elastic modulus of 410~710 GPa, and a tensile strength of 3~6 GPa.

[0011] Preferably, the steel fiber is a single copper-plated steel fiber or a mixture of copper-plated steel fibers with different aspect ratios and multi-anchor steel fibers.

[0012] Preferably, the copper-plated steel fiber has a nominal length of 12~23 mm, an equivalent diameter of 0.20~0.25 mm, a tensile strength ≥2000 MPa, and an elastic modulus of 200~220 GPa.

[0013] Preferably, the nominal length of the multi-anchor steel fiber is 20~30 mm, the equivalent diameter is 0.30~0.40 mm, the tensile strength is ≥1000 MPa, and the elastic modulus is 210~230 GPa.

[0014] Preferably, the cementitious material includes: cement 550~800 kg / m³ 3 Fly ash microspheres 100~170 kg / m³ 3 Silica fume 120~180 kg / m³ 3 Expanding agent 50~80 kg / m 3 .

[0015] Preferably, the fly ash microspheres have a 28-day activity index > 110%, a water requirement ratio of 102%, and a spherical particle volume fraction ≥ 95%.

[0016] Preferably, the cement is P·O 52.5 or P·II 52.5 type silicate cement. The silica fume has a SiO2 mass content ≥95% and a specific surface area ≥18000 m². 2 / kg, 28-day activity index ≥100%.

[0017] Preferably, the lead powder is industrial-grade lead powder, and its main components are a mixture of lead oxide and lead, with the content of lead oxide and lead being >99%. The main component of the barite powder is BaSO4, and the content of BaSO4 is >99%.

[0018] The apparent density of the high-titanium heavy slag sand is 3100 kg / m³. 3 It has a fineness modulus of 2.8 and a saturated surface dry water absorption rate of 7.0~12.0%.

[0019] The apparent density of the selected magnetite aggregate is 6040 kg / m³. 3 It has a fineness modulus of 3.1 and an Fe2O3 content of >75%.

[0020] The apparent density of the barite aggregate is 3620 kg / m³.3 It has a fineness modulus of 2.5 and a BaSO4 content of >65%.

[0021] The apparent density of the hematite aggregate is 4970 kg / m³. 3 It has a fineness modulus of 3.4 and an Fe2O3 content of >40%.

[0022] Preferably, it also includes 15~30 kg / m³ of polycarboxylate superplasticizer. 3 Mixed with water 170~220 kg / m 3 .

[0023] A method for preparing high-performance concrete that protects against gamma-ray radiation includes the following steps: S1. Weigh each raw material according to the proportions; S2. Add the gamma-ray shielding cementitious components, cementitious materials, gamma-ray shielding aggregates, and CaCO3 whiskers to a concrete mixer and premix for 1-3 minutes until homogeneous. Then, pour in 70%-90% water and polycarboxylate superplasticizer and wet mix for 3-5 minutes. Next, sprinkle in steel fibers and mix evenly. Add the remaining water to the mixer and mix for another 1-3 minutes until homogeneous. After molding, vibration, and shaping, cover the surface with an impermeable film for film curing, then remove the mold. Finally, perform standard curing or steam curing until the specified age.

[0024] The principle employed in this invention is as follows: 1. This invention uses gamma-ray shielding aggregates and gamma-ray shielding cementitious components as fine aggregates and partial cementitious materials, respectively, to prepare ultra-high performance concrete (UHPC). The main purpose is to introduce a large amount of high atomic number elements such as Fe and Ba into the UHPC material system. The introduction of these heavy elements can significantly increase the apparent density of UHPC, enhancing the energy loss of UHPC materials during photoelectric effect, Compton scattering, and pair emission of incident gamma rays. In other words, the large-scale introduction of heavy elements increases the interaction cross-section of gamma rays in UHPC during these processes. Therefore, the presence of gamma-ray shielding aggregates and gamma-ray shielding cementitious components improves the gamma-ray shielding performance of UHPC materials. Furthermore, the Fe element in the steel fibers also plays a positive role in improving the apparent density and gamma-ray shielding performance of UHPC materials.

[0025] 2. This invention employs various types of hybrid steel fibers and CaCO3 whiskers as reinforcing and toughening components for UHPC materials, primarily to improve the dynamic impact performance of UHPC materials under high-speed impact. The steel fibers with smaller aspect ratios are numerous and closely spaced, mainly responsible for reinforcing the matrix and inhibiting the initiation and early development of microcracks; the steel fibers with larger aspect ratios are mainly responsible for bridging macroscopic cracks that have already expanded, providing a higher later-stage toughening effect; the multi-anchor steel fibers achieve more efficient and durable mechanical interlocking through end anchors. When cracks open and fibers begin to be pulled out of the matrix, the end anchors strongly interlock with the surrounding matrix material, thus enabling the fiber and matrix to share the force, thereby achieving passive dissipation of impact energy; while the diameter and length of the CaCO3 whiskers are 0.5~2 μm and 10~20 μm, respectively. μm can achieve crack prevention and reinforcement of UHPC cement paste at the micron scale. It dissipates a large amount of fracture energy through whisker pull-out and crack deflection. At the same time, the uniformly dispersed CaCO3 whiskers can not only fill the micropores in the cement matrix, making the matrix more compact, but also serve as nucleation points for heterogeneous nucleation of slurry hydration products, promoting the hydration of cementitious materials and optimizing the structure of the interface transition zone.

[0026] 3. This invention selects silica fume and fly ash microspheres as mineral admixtures, which work together with additives to regulate the workability of UHPC materials. Silica fume contains a large amount of amorphous SiO2, which has a large viscous resistance, and can significantly improve the segregation and bleeding of fresh concrete and increase the viscosity of UHPC materials. The ball-bead effect, filling and water-reducing effect of fly ash microspheres can not only effectively improve the fluidity and homogeneity of fresh concrete, but also fill the voids in UHPC, enhance the density of the cementitious paste, and improve the mechanical properties and durability of concrete. The introduction of water-reducing agents can not only reduce the water-cement ratio of UHPC materials and improve the mechanical properties of UHPC materials, but also effectively regulate the workability of UHPC materials.

[0027] The beneficial effects of this invention compared to the prior art are as follows: 1. This invention uses gamma-ray shielding aggregate as fine aggregate and replaces part of the cementitious material with gamma-ray shielding cementitious components to prepare impact-resistant gamma-ray shielding ultra-high performance concrete. The magnetite, barite, and hematite aggregates in the gamma-ray shielding aggregate contain a large proportion of Fe and Ba elements, respectively, which can significantly increase the density of the prepared UHPC material, thereby enhancing its gamma-ray shielding capability. High-titanium heavy slag sand is waste slag generated during the smelting of vanadium-titanium magnetite, containing more than 20% TiO2 and about 10% elemental iron and its oxides. Its application in gamma-ray shielding UHPC material not only enhances its gamma-ray shielding performance but also alleviates, to some extent, the pollution of land and environment caused by the large accumulation of industrial solid waste. The lead powder and barite powder in the gamma-ray shielding cementitious components contain large amounts of Pb and Ba elements, respectively, which can further improve the density and gamma-ray shielding performance of the UHPC material. In addition, the volumetric content of steel fiber reaches more than 2.5%, and its incorporation also has a beneficial effect on the gamma-ray shielding performance of the UHPC material. By optimizing the mix proportions of cementitious materials, aggregates, and fibers for UHPC, the prepared UHPC material exhibits a 5% to 44% improvement in gamma-ray shielding performance compared to ordinary quartz sand UHPC.

[0028] 2. This invention uses various types of hybrid steel fibers and CaCO3 whiskers as toughening and crack-resistant components for UHPC materials. By designing different types of steel fibers and CaCO3 whiskers in the UHPC mix proportion, the aim is to maximize the crack-resistant effect of different toughening and crack-resistant components, suppress the initiation and propagation of cracks in UHPC materials under high-speed impact, and thus improve the dynamic compressive strength and impact toughness of UHPC materials. Regarding the roles of different types of steel fibers and CaCO3 whiskers in UHPC materials, specifically, when crack initiation or microcracks are small, steel fibers with smaller aspect ratios inhibit the initiation and early development of microcracks; when cracks extend to a certain size, steel fibers with larger aspect ratios bridge the extending cracks; the mechanical interlocking between the anchor points of multi-anchored steel fibers and the matrix achieves synergistic stress distribution between the matrix and fibers, reducing the probability of steel fiber pull-out under impact; in addition, CaCO3 whiskers can also achieve crack prevention and reinforcement of UHPC cementitious slurry at the micron scale, dissipating a large amount of fracture energy through whisker pull-out and crack deflection. At the same time, uniformly dispersed CaCO3 whiskers can not only fill the micropores in the cement matrix, making the matrix more compact, but also serve as nucleation sites for heterogeneous nucleation of slurry hydration products, promoting the hydration of cementitious materials and optimizing the structure of the interface transition zone.

[0029] 3. The apparent density of the impact-resistant gamma-ray shielding ultra-high performance concrete obtained by this invention is 2660~3680 kg / m³. 3Meanwhile, its compressive strength can reach C100 or higher, and it has good working performance, mechanical properties and volume stability. It can effectively improve the toughness, impact resistance, durability and gamma-ray shielding performance of UHPC components, and has important practical application value. Detailed Implementation

[0030] To make the technical problem to be solved, the technical solution, and the beneficial effects of the present invention clearer, the present invention will be further described in detail with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. The technical solution of the present invention will be described in detail below with reference to embodiments, but the scope of protection is not limited thereto.

[0031] The following comparative examples and embodiments: The cement used is P.Ⅱ 52.5 type Portland cement produced by Hubei Waishi Cement, with an apparent density of 3.16 g / cm³. 3 Specific surface area is 340 kg / m² 3 ; The fly ash microspheres had a 28-day activity index of 113%, a water requirement ratio of 102%, and were amorphous. They were provided by Tianjin Zhucheng New Material Technology Co., Ltd. The specific surface area of ​​silica fume is 18300 m². 2 / kg, SiO2 mass content is 94%, and 28-day activity index is 105%; The gamma-ray shielding cementing components are industrial-grade lead powder (mainly a mixture of lead oxide and lead) produced in Zhengzhou, Henan Province, and barite powder (mainly BaSO4) produced in Lingshou, Hebei Province. The expanding agent is a CaO-MgO composite expanding agent produced by a company in Wuhan, with a specific surface area of ​​330 m². 2 / kg, the limiting swelling rate in water over 7 days is 0.065%; The high-titanium heavy slag sand in the gamma-ray shielding aggregate was produced by a group in Sichuan Province, with an apparent density of 3100 kg / m³. 3 The porosity is 19%, and the water absorption rate in the saturated surface-dry state is 11.2%. Magnetite, barite, and hematite are all produced in Lingshou County, Hebei Province, with apparent densities of 6040 kg / m³. 3 3620 kg / m 3 and 4970 kg / m 3 ; There are three main types of steel fibers. Type I copper-plated steel fibers have a nominal length of 13 mm, an equivalent diameter of 0.25 mm, and a tensile strength of over 2200 MPa. Type II copper-plated steel fibers have a nominal length of 22 mm, an equivalent diameter of 0.20 mm, and a tensile strength of over 2000 MPa. Multi-anchor steel fibers (Type III) have a nominal length of 25 mm, an equivalent diameter of 0.35 mm, and a tensile strength of over 1000 MPa. CaCO3 whiskers, produced by a company in Hebei Province, are a micron-sized fibrous inorganic filler material with an apparent density of 2800 kg / m³. 3 The diameter and length are 0.5~2 μm and 10~20 μm, respectively, the elastic modulus can reach 410~710 GPa, and the tensile strength can reach 3~6 GPa; The water-reducing agent is a UHPC-specific polycarboxylate high-efficiency water-reducing agent produced by a company in Wuhan, with a solid content of 40% and a water reduction rate of 25%; the water is ordinary tap water. Example 1

[0032] This embodiment proposes a high-performance concrete that protects against gamma-ray radiation. The raw material mix proportions are shown in Table 1. ; Example 1 uses cement, silica fume, fly ash microspheres, and an expanding agent as cementing materials, and gamma-ray shielding aggregate as fine aggregate. In this example, the gamma-ray shielding aggregate is specifically high-titanium heavy slag sand; the high-titanium heavy slag sand needs to be soaked in clean water for more than 24 hours until it reaches a saturated surface-dry state. In addition, the steel fiber used in Example 1 is type I copper-plated steel fiber. Example 2

[0033] This embodiment proposes a high-performance concrete that protects against gamma-ray radiation. The raw material mix proportions are shown in Table 2. ; Example 2 uses gamma-ray shielding aggregate as fine aggregate. In this example, the gamma-ray shielding aggregate is specifically a mechanical mixture of barite aggregate, hematite aggregate, and high-titanium heavy ore slag sand, with a volume ratio of 3:1:1. The volume of the gamma-ray shielding aggregate in this example is equal to that in Example 1. In this embodiment, gamma-ray shielding cementitious components are used to replace 10% of the cementitious material in Example 1 by mass. Furthermore, the steel fibers used in Example 2 are Type I copper-plated steel fibers. Example 3

[0034] This embodiment proposes a high-performance concrete that protects against gamma-ray radiation. The raw material mix proportions are shown in Table 3. ; Example 3 uses gamma-ray shielding aggregate as fine aggregate. In this example, the gamma-ray shielding aggregate is the same as in Example 2. The volume of the gamma-ray shielding aggregate in this example is the same as that in Example 1. In this embodiment, gamma-ray shielding cementitious components are used to replace 5% of the cementitious material in Example 1 by mass. Furthermore, the steel fibers used in Example 3 are Type I copper-plated steel fibers. Example 4

[0035] This embodiment proposes a high-performance concrete that protects against gamma-ray radiation. The raw material mix proportions are shown in Table 4. ; The fine aggregate and cementitious material used in this embodiment are the same as in Example 3. The difference is that the steel fibers used in Example 4 are a mixture of Type I, Type II, and Type III steel fibers in a mass ratio of 10:4:12. Furthermore, to further improve the toughness of the prepared UHPC material, Example 4 also incorporates 0.5% CaCO3 whiskers by mass into the mix proportion. Example 5

[0036] This embodiment proposes a high-performance concrete that protects against gamma-ray radiation. The raw material mix proportions are shown in Table 5. ; The fine aggregate and cementitious material used in this embodiment are the same as in Example 2. Unlike Example 2, the steel fibers used in Example 5 are a mixture of Type I, Type II, and Type III steel fibers in a mass ratio of 10:4:12. Furthermore, to further improve the toughness of the prepared UHPC material, Example 5 also incorporates 0.5% CaCO3 whiskers by mass into the mix proportion.

[0037] Comparative Example The comparative example was used to compare with Examples 1-5. To ensure the reliability of the comparison results, the amounts of cementitious materials, water, and water-reducing agent in the comparative example were kept consistent with those in Example 1. The difference was that the comparative example used conventional silica sand as the fine aggregate, and the amount of silica sand was ensured to be an equal volume replacement of the γ-ray shielding aggregate in Examples 1-5. Consistent with Examples 1-3, the comparative example also used 2.5% by volume of Type I copper-plated steel fiber as the toughening component. Specific mix proportions are shown in Table 6. ; Example 6

[0038] A method for preparing high-performance concrete that protects against gamma-ray radiation is provided. Taking the composition of Example 5 as an example, the preparation steps are as follows: S1. Weigh each raw material according to the proportions described in Table 5; 2) Add the cementitious materials, including the gamma-ray shielding cementitious components and expanding agent, CaCO3 whiskers and gamma-ray shielding aggregates to the concrete mixer and premix for 3 minutes until visually uniform. Then pour in 80% water and all of the polycarboxylate superplasticizer and wet mix for 5 minutes. Finally, sprinkle in the steel fibers and mix evenly. Add the remaining water to the slurry and mix for 5 minutes until uniform. After molding, vibration and shaping, cover the surface with a waterproof film for film curing, then remove the mold. Finally, perform standard curing until the specified age to obtain high-performance concrete that protects against gamma-ray radiation.

[0039] Concrete was prepared using the raw materials of the comparative example and Examples 1-4 according to the above preparation method; the performance test results of the high-performance concrete obtained by the comparative example and each example are shown in Tables 7-9.

[0040] ; ; ; The above results indicate that, compared to the comparative example, the working performance of the UHPC material obtained in Example 1 was improved, while the working performance of the UHPC materials obtained in Examples 2-5 decreased to varying degrees. Compared to working performance, the apparent density and 28-day compressive strength of the UHPC materials obtained in Examples 1-5 were improved, especially in Example 5, where the apparent density, 28-day compressive strength, and 28-day flexural strength were increased by 50.12%, 29.44%, and 22.10%, respectively, compared to the comparative example.

[0041] Compared to the comparative example, the gamma-ray shielding performance of Example 1 was improved by 5.55%, while the improvement in gamma-ray shielding performance of Examples 2-5 reached 35.84%~43.71%. Compared to UHPC materials prepared from ordinary quartz sand, UHPC materials prepared from gamma-ray shielding aggregates and gamma-ray shielding functional components exhibit superior shielding performance. 60 When the Co-source gamma-ray dose reaches 90%, the sample thickness can be reduced by a maximum of 4.91 cm.

[0042] Compared with the comparative examples, the dynamic compressive strength and impact toughness of Examples 4-5 were improved to varying degrees. Compared with Examples 2-3, which did not have hybrid fiber design and did not contain CaCO3 whiskers, the dynamic compressive strength of Examples 4 and 5 increased by 37.37% and 34.44%, respectively; the dynamic peak toughness increased by 18.85% and 12.18%, respectively; and the dynamic ultimate toughness increased by 13.91% and 22.93%, respectively.

[0043] In summary, the impact-resistant gamma-ray shielding ultra-high performance concrete obtained by this invention, especially the UHPC material obtained in Examples 4-5, possesses excellent mechanical properties, dynamic impact resistance, and gamma-ray shielding performance. The apparent density of the obtained ultra-high performance concrete can reach up to 3680 kg / m³. 3 Compared to quartz sand UHPC, the weight of the resulting UHPC increases by more than 50%, and its 28-day compressive strength can reach over 150 MPa. Compared to quartz sand UHPC, the resulting impact-resistant γ-ray shielding UHPC material shows improvements of up to 43%, 35%, and 20% or more in γ-ray shielding performance, dynamic compressive strength, and impact ultimate toughness.

[0044] This invention uses one or more of the following aggregates: selected magnetite aggregate, barite aggregate, hematite aggregate, and high-titanium heavy ore slag sand. Lead powder and barite powder are used as gamma-ray shielding cementing components. The invention leverages the high atomic number elements such as Fe, Ba, and Pb in the gamma-ray shielding cementing components and the gamma-ray shielding aggregates. 60 The Compton scattering and photoelectric absorption between Co-source gamma rays reduce gamma ray energy and absorb photons. A mixture of copper-plated steel fibers with different aspect ratios and multi-anchor steel fibers, incorporating CaCO3 whiskers, serves as a reinforcing and toughening material for impact-resistant and radiation-shielding UHPC. The hybrid fibers and CaCO3 whiskers enhance the dynamic impact performance of the UHPC material at different scales. The steric hindrance effect of polycarboxylate superplasticizer and the "ball effect" of fly ash microspheres optimize the working performance of the UHPC and improve its density. An expanding agent reduces the self-shrinkage and drying shrinkage of the UHPC, improving its volumetric stability. The impact-resistant gamma-ray shielding UHPC material described in this invention, while improving its dynamic impact performance and gamma-ray shielding performance, also possesses excellent working performance, mechanical properties, and durability, making it of significant practical application value.

[0045] It should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0046] The detailed descriptions listed above are merely specific descriptions of feasible implementation methods of this application and are not intended to limit the scope of protection of this application. All equivalent implementation methods or modifications made without departing from the spirit of the art of this application should be included within the scope of protection of this invention.

Claims

1. A high-performance concrete that protects against gamma-ray radiation, characterized in that, Includes cementitious materials and gamma-ray shielding aggregates of 1000~2400 kg / m³ 3 γ-ray shielding gel component ≤95 kg / m 3 200~260 kg / m² of steel fiber 3 The gamma-ray shielding cementitious component is one or a mixture of two of lead powder and barite powder; the gamma-ray shielding aggregate is one or a mixture of several of selected magnetite aggregate, barite aggregate, hematite aggregate, and high-titanium heavy ore slag sand.

2. The high-performance concrete for protecting against gamma-ray radiation according to claim 1, characterized in that, Also includes ≤15kg / m 3 CaCO3 whiskers.

3. The high-performance concrete for protecting against gamma-ray radiation according to claim 2, characterized in that, The apparent density of the CaCO3 whiskers is 2800 kg / m³. 3 It has a diameter of 0.5~2 μm, a length of 10~20 μm, an elastic modulus of 410~710 GPa, and a tensile strength of 3~6 GPa.

4. The high-performance concrete for shielding against gamma-ray radiation according to claim 1, characterized in that, The steel fiber is a single copper-plated steel fiber or a mixture of copper-plated steel fibers with different aspect ratios and multi-anchor steel fibers.

5. The high-performance concrete for protecting against gamma-ray radiation according to claim 4, characterized in that, The copper-plated steel fiber has a nominal length of 12~23 mm, an equivalent diameter of 0.20~0.25 mm, a tensile strength ≥2000 MPa, and an elastic modulus of 200~220 GPa.

6. The high-performance concrete for shielding against gamma-ray radiation according to claim 4, characterized in that, The nominal length of the multi-anchor steel fiber is 20~30 mm, the equivalent diameter is 0.30~0.40 mm, the tensile strength is ≥1000 MPa, and the elastic modulus is 210~230 GPa.

7. The high-performance concrete for shielding against gamma-ray radiation according to claim 1, characterized in that, Cementitious materials include: cement 550~800 kg / m³ 3 Fly ash microspheres 100~170 kg / m³ 3 Silica fume 120~180 kg / m³ 3 Expanding agent 50~80 kg / m 3 .

8. The high-performance concrete for shielding against gamma-ray radiation according to claim 7, characterized in that, The fly ash microspheres have a 28-day activity index >110%, a water requirement ratio of 102%, and a spherical particle volume fraction ≥95%.

9. The high-performance concrete for protecting against gamma-ray radiation according to claim 1, characterized in that, It also includes polycarboxylate superplasticizer at 15~30 kg / m² 3 Mixed with water 170~220 kg / m 3 .

10. The method for preparing high-performance concrete that protects against gamma-ray radiation according to claim 2, characterized in that, Includes the following steps: S1. Weigh each raw material according to the proportions; S2. Add the gamma-ray shielding cementitious components, cementitious materials, gamma-ray shielding aggregates, and CaCO3 whiskers to a concrete mixer and premix for 1-3 minutes until homogeneous. Then, pour in 70%-90% water and polycarboxylate superplasticizer and wet mix for 3-5 minutes. Next, sprinkle in steel fibers and mix evenly. Add the remaining water to the mixer and mix for another 1-3 minutes until homogeneous. After molding, vibration, and shaping, cover the surface with an impermeable film for film curing, then remove the mold. Finally, perform standard curing or steam curing until the specified age.