High-performance anti-penetration concrete and preparation method thereof

Abstract

The invention relates to the technical field of special low-carbon building materials, in particular to high-performance anti-penetration concrete and a preparation method thereof.The high-performance anti-penetration concrete is prepared by taking industrial solid waste as a cementing material, taking waste nano ceramic balls, carbonized steel slag coarse aggregate and modified steel slag fine aggregate as aggregate and matching basalt fiber, wollastonite fiber and nano carbon fiber for composite toughening; a water reducing agent and a retarder are added as additives, so that the high-performance anti-penetration concrete which is good in fluidity, high in mechanical property and excellent in anti-penetration performance is prepared.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of special low-carbon building materials, in particular to a high-performance anti-penetration concrete and a preparation method thereof. BACKGROUND

[0002] The anti-penetration concrete is a material specially designed or reinforced, which can significantly improve the battlefield survivability of structural facilities, ensure the safety of military command and weapon equipment in war environment, and guarantee the operation of people's livelihood. The research and development of the anti-penetration concrete in the prior art focuses on three directions, one is to add steel fibers to improve the toughness of the concrete, the second is to use high-strength coarse aggregate to improve the anti-penetration performance, and the third is to set a functional gradient layer to improve the comprehensive protection capability. However, the steel fibers are not easy to disperse, the preparation and construction of the concrete are difficult, the source of the high-strength coarse aggregate is limited, which is a non-renewable resource, and the preparation process of the multi-layer functional gradient concrete is complex, and a large amount of high-strength cement is used, which is high in cost.

[0003] Grinding is one of the main processing procedures in the mineral processing process. Through the impact grinding of the grinding medium on the mineral, the mineral is broken and refined. In recent years, nano ceramic balls are more used for grinding. In the preparation process of the nano ceramic ball, rare earth materials and oxides are added, and the fineness of the calcined powder and the calcination temperature are strictly controlled. The nano ceramic ball has the advantages of lighter weight, higher strength, good wear resistance, strong heat resistance and corrosion resistance, and the particle size can be as large as φ25mm or more. During use, the grinding medium loss and grinding power consumption can be reduced. During the grinding process, some small particle size balls will escape from the grate plate during use. During the grinding process, the grinding medium will be abandoned. The shape of the abandoned nano ceramic ball changes due to wear. Generally, it is abandoned and not recycled.

[0004] Cement production emits a large amount of carbon dioxide. Solid waste recycling is a hot topic in the development of the building materials industry. Most anti-penetration concretes are produced using high-strength cement. How to use solid waste to meet the performance requirements of anti-penetration concrete still has a technical gap. SUMMARY

[0005] To solve the problems in the prior art, the present application provides a high-performance anti-penetration concrete. Industrial solid waste is used as a cementitious material, waste nano ceramic balls, carbonized steel slag coarse aggregate, and modified steel slag fine aggregate are used as aggregate, and basalt fiber, wollastonite fiber, and nano carbon fiber are used for composite toughening. Water reducing agent and retarder are used as admixtures to prepare a high-performance anti-penetration concrete with good fluidity, high mechanical properties, and excellent anti-penetration performance.

[0006] Specifically, the high-performance anti-penetration concrete of this invention is composed of the following raw materials in parts by weight: 320-350 parts mineral powder, 200-220 parts metakaolin, 150-160 parts red mud, 20-40 parts silica fume, 15-20 parts sodium silicate, 5-8 parts high-alumina cement clinker, 450-500 parts waste nano-ceramic balls, 500-550 parts coarse aggregate of carbonized steel slag, 800-850 parts modified steel slag fine aggregate, 3-5 parts basalt fiber, 2-5 parts wollastonite fiber, 2-4 parts nano-carbon fiber, 7-12 parts water-reducing agent, 3-6 parts retarder, and 150-165 parts water. The modified steel slag fine aggregate is prepared by soaking the steel slag fine aggregate in saturated lime water for water saturation treatment, followed by carbonization treatment.

[0007] This invention first studies the aggregate system. A major factor in the penetration resistance of concrete is the aggregate, especially the composition of coarse aggregate. Nano-ceramic balls, as grinding media, have high hardness and strength. The discarded nano-ceramic balls are roughly irregularly elliptical in shape, with a particle size still within the range of coarse aggregates used in concrete. Moreover, their density is close to that of corundum aggregate and slightly larger than that of ordinary coarse aggregates used in concrete. This invention reuses them to prepare penetration-resistant concrete. Through extensive experiments, they are used together with carbonized steel slag coarse aggregate as coarse aggregate. Steel slag is a by-product of the steelmaking industry and has the characteristics of high strength and wear resistance. This invention carbonizes it to eliminate the potential for volume stability issues. The discarded ceramic coarse aggregate and the carbonized steel slag coarse aggregate form a high-strength skeleton, improving the penetration resistance of concrete. The two have a good synergistic effect. The experiment found that if the discarded ceramic coarse aggregate is used alone as coarse aggregate, its penetration resistance effect will be weakened. This may be because the surface of the discarded ceramic coarse aggregate has relatively fewer edges and corners, resulting in a slightly poorer bonding effect with the concrete slurry interface.

[0008] After selecting the coarse aggregate, this invention selects materials for the cementitious material system. The composition of the cementitious material system affects the workability and mechanical properties of concrete. This invention uses mineral powder and metakaolin as the main active substances, adds red mud and sodium silicate as activators, and adds silica fume to supplement the cementitious activity. The cementitious material paste has a moderate viscosity, requiring no thickener, and blends well with the aggregate. To further improve the density of concrete, this invention uses modified steel slag fine aggregate, which is soaked in saturated lime water and then carbonated to generate micro-nano-sized calcium carbonate fine particles, which not only fill the steel slag fine aggregate... The micropores and relatively rough surface facilitate the tight interlocking of coarse aggregate, fine aggregate, and cementitious material, improving the impact resistance of waste nano-ceramic balls as coarse aggregate in concrete. Furthermore, the micro- and nano-sized calcium carbonate can serve as hydration active sites for cementitious material, promoting its hydration. This invention further adds a small amount of high-alumina cement clinker, which can promote the hydration of cementitious active substances. The calcium aluminate minerals therein can react with the micro- and nano-sized calcium carbonate particles on the surface of fine aggregate to generate hydrated calcium carboaluminate, improving the transition zone at the aggregate interface, thereby further enhancing the concrete's impact resistance.

[0009] Preferably, the mineral powder is at least one of S95 grade and S105 grade.

[0010] Preferably, the waste nano-ceramic balls are waste grinding media generated during the mill grinding process, with a particle size of 5-8 mm. Preferably, the waste nano-ceramic balls are primarily made of at least one of zirconium oxide-based, silicon nitride-based, and alumina-based materials.

[0011] Preferably, the carbonized steel slag coarse aggregate is obtained by carbonizing steel slag coarse aggregate, and the particle size of the steel slag coarse aggregate is 5-20mm.

[0012] Preferably, the carbonization process involves carbonizing with CO2-containing gas for 18-36 hours at a pressure of 0.2-0.5 MPa. More preferably, the CO2-containing gas is an industrial product or industrial waste gas.

[0013] Preferably, in the modified steel slag fine aggregate preparation process, the particle size of the steel slag fine aggregate is 0.5-4.25 mm.

[0014] Preferably, the basalt fiber has a length of 3-5 mm, the wollastonite fiber has a length of 0.5-1 mm, and the carbon nanofiber has a diameter of 150-200 nm and a length of 10-20 μm.

[0015] In existing technologies, steel fibers are added to concrete to form a constraint and improve its resistance to penetration. However, they are difficult to disperse, difficult to form, and the steel fibers tend to sink. This invention is a coarse aggregate and cementitious material system that combines waste nano-ceramic balls and coarse aggregate of carbide steel slag. After extensive testing and screening, basalt fiber, wollastonite fiber and nano-carbon fiber are used to improve the toughness of concrete. When subjected to projectile impact, the concrete structure can remain intact and not crack, thus improving the overall resistance of concrete to penetration.

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

[0017] Preferably, the retarder is at least one of borax, sodium gluconate, and sucrose.

[0018] This invention also relates to a method for preparing the above-mentioned high-performance penetration-resistant concrete, specifically comprising the following steps:

[0019] 1) Weigh each ingredient according to its weight.

[0020] 2) Mix all ingredients thoroughly.

[0021] 3) Shape and cure, and you will get the product.

[0022] This invention does not impose specific restrictions on the mixing order of the raw materials. As long as the raw materials are mixed evenly and the concrete has good workability, it falls within the protection scope of this invention. This includes, but is not limited to, mixing powder, adding aggregates and mixing, dissolving admixtures in water and then mixing, or mixing powder and then adding some water and then adding aggregates and mixing, dissolving admixtures in the remaining water and then mixing, or mixing powder and then adding water containing admixtures and then adding aggregates and mixing. Detailed Implementation

[0023] To characterize the technical effects of this invention, concrete was prepared and its performance was tested. The penetration resistance test was a scaled-down test. The concrete cylindrical target had a diameter of 0.6 m and a thickness of 1.5 m. A 3 mm thick steel cylinder was wrapped around the outer perimeter of the cylindrical target to reduce the target boundary effect. The armor-piercing projectile was made of 35CrMnSi steel, with a length of 185 mm, a diameter of 28.2 mm, a CRH of 3, and a wall thickness of 3.3 mm. During the test, S105 grade mineral powder was selected. The waste nano-ceramic balls were alumina-based with a particle size of 5-8 mm. The coarse aggregate of carbonized steel slag was obtained by carbonizing 5-20 mm steel slag coarse aggregate under 90% CO2 gas at 0.2 MPa pressure for 24 hours. The modified steel slag fine aggregate was obtained by soaking 0.5-4.25 mm steel slag fine aggregate in saturated lime water, followed by carbonization under 90% CO2 gas at 0.3 MPa pressure for 20 hours. During the mechanical property testing, the concrete specimens were cured to standard for 28 days, while the concrete cylindrical target was naturally cured to 28 days during the penetration resistance test.

[0024] Example 1

[0025] Concrete is composed of the following raw materials in parts by weight: 330 parts mineral powder, 220 parts metakaolin, 150 parts red mud, 20 parts silica fume, 17 parts sodium silicate, 7 parts high-alumina cement clinker, 470 parts waste nano-ceramic balls, 530 parts coarse aggregate of carbonized steel slag, 840 parts fine aggregate of modified steel slag, 4 parts basalt fiber, 3 parts wollastonite fiber, 3 parts nano-carbon fiber, 11 parts water-reducing agent, 4 parts retarder, and 160 parts water.

[0026] Tests showed that the initial slump spread of the concrete was 700 mm, the 28-day compressive strength was 125 MPa, the 28-day flexural strength was 10.9 MPa, the projectile's impact velocity was 523 m / s, the penetration depth was 92 mm, and the crater diameter was 136 mm. Additionally, tests showed that the projectile's impact velocity was 905 m / s, the penetration depth was 133 mm, and the crater diameter was 157 mm.

[0027] Example 2

[0028] Concrete is composed of the following raw materials in parts by weight: 340 parts mineral powder, 200 parts metakaolin, 150 parts red mud, 30 parts silica fume, 18 parts sodium silicate, 8 parts high-alumina cement clinker, 500 parts waste nano-ceramic balls, 510 parts coarse aggregate of carbonized steel slag, 850 parts fine aggregate of modified steel slag, 3 parts basalt fiber, 4 parts wollastonite fiber, 4 parts nano-carbon fiber, 12 parts water-reducing agent, 4 parts retarder, and 160 parts water.

[0029] Tests showed that the initial slump spread of the concrete was 710 mm, the 28-day compressive strength was 132 MPa, the 28-day flexural strength was 11.6 MPa, the projectile's impact velocity was 526 m / s, the penetration depth was 89 mm, and the crater diameter was 132 mm. Tests also showed that the projectile's impact velocity was 911 m / s, the penetration depth was 128 mm, and the crater diameter was 144 mm.

[0030] Comparative Example 1

[0031] Concrete is composed of the following raw materials in parts by weight: 350 parts P·O52.5 cement, 200 parts fly ash, 120 parts mineral powder, 30 parts silica fume, 500 parts waste nano-ceramic balls, 510 parts coarse aggregate of carbonized steel slag, 850 parts fine aggregate of modified steel slag, 3 parts basalt fiber, 4 parts wollastonite fiber, 4 parts nano-carbon fiber, 12 parts water-reducing agent, 4 parts retarder, and 160 parts water.

[0032] Tests showed that the initial slump spread of the concrete was 680 mm, the 28-day compressive strength was 127 MPa, the 28-day flexural strength was 11.5 MPa, the projectile's impact velocity was 519 m / s, the penetration depth was 98 mm, and the crater diameter was 145 mm. Additionally, tests showed that the projectile's impact velocity was 908 m / s, the penetration depth was 132 mm, and the crater diameter was 160 mm.

[0033] Comparative Example 2

[0034] Concrete is composed of the following raw materials in parts by weight: 340 parts mineral powder, 230 parts fly ash, 158 parts red mud, 18 parts sodium silicate, 500 parts waste nano-ceramic balls, 510 parts coarse aggregate of carbonized steel slag, 850 parts fine aggregate of modified steel slag, 3 parts basalt fiber, 4 parts wollastonite fiber, 4 parts nano-carbon fiber, 12 parts water-reducing agent, 4 parts retarder, and 160 parts water.

[0035] Tests showed that the initial slump spread of the concrete was 720 mm, the 28-day compressive strength was 107 MPa, the 28-day flexural strength was 9.6 MPa, the projectile's impact velocity was 521 m / s, the penetration depth was 118 mm, and the crater diameter was 172 mm. Additionally, tests showed that the projectile's impact velocity was 913 m / s, the penetration depth was 176 mm, and the crater diameter was 197 mm.

[0036] Comparative Example 3

[0037] Concrete is composed of the following raw materials in parts by weight: 340 parts mineral powder, 200 parts metakaolin, 150 parts red mud, 30 parts silica fume, 18 parts sodium silicate, 8 parts high-alumina cement clinker, 1100 parts coarse aggregate of carbonized steel slag, 850 parts fine aggregate of modified steel slag, 3 parts basalt fiber, 4 parts wollastonite fiber, 4 parts nano carbon fiber, 12 parts water-reducing agent, 4 parts retarder, and 160 parts water.

[0038] Tests showed that the initial slump spread of the concrete was 670 mm, the 28-day compressive strength was 119 MPa, the 28-day flexural strength was 10.7 MPa, the projectile's impact velocity was 508 m / s, the penetration depth was 165 mm, and the crater diameter was 227 mm. Additionally, tests showed that the projectile's impact velocity was 908 m / s, the penetration depth was 265 mm, and the crater diameter was 243 mm.

[0039] Comparative Example 4

[0040] Concrete is composed of the following raw materials in parts by weight: 340 parts mineral powder, 200 parts metakaolin, 150 parts red mud, 30 parts silica fume, 18 parts sodium silicate, 8 parts high-alumina cement clinker, 1100 parts waste nano-ceramic balls, 850 parts modified steel slag fine aggregate, 3 parts basalt fiber, 4 parts wollastonite fiber, 4 parts nano-carbon fiber, 12 parts water-reducing agent, 4 parts retarder, and 160 parts water.

[0041] Tests showed that the initial slump spread of the concrete was 720 mm, the 28-day compressive strength was 97 MPa, the 28-day flexural strength was 9.1 MPa, the projectile's impact velocity was 522 m / s, the penetration depth was 149 mm, and the crater diameter was 185 mm. Additionally, tests showed that the projectile's impact velocity was 904 m / s, the penetration depth was 166 mm, and the crater diameter was 198 mm.

[0042] Comparative Example 5

[0043] Concrete is composed of the following raw materials in parts by weight: 340 parts mineral powder, 200 parts metakaolin, 150 parts red mud, 30 parts silica fume, 18 parts sodium silicate, 8 parts high-alumina cement clinker, 500 parts waste nano-ceramic balls, 510 parts coarse aggregate of carbonized steel slag, 850 parts fine aggregate of modified steel slag, 6 parts polyvinyl alcohol fiber, 5 parts glass fiber, 12 parts water-reducing agent, 4 parts retarder, and 160 parts water.

[0044] Tests showed that the initial slump spread of the concrete was 700 mm, the 28-day compressive strength was 129 MPa, the 28-day flexural strength was 10.2 MPa, the projectile's impact velocity was 510 m / s, the penetration depth was 125 mm, and the crater diameter was 163 mm. Additionally, tests showed that the projectile's impact velocity was 909 m / s, the penetration depth was 177 mm, and the crater diameter was 186 mm.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-performance penetration-resistant concrete, characterized in that... It is composed of the following raw materials in parts by weight: 320-350 parts mineral powder, 200-220 parts metakaolin, 150-160 parts red mud, 20-40 parts silica fume, 15-20 parts sodium silicate, 5-8 parts high-alumina cement clinker, 450-500 parts waste nano-ceramic balls, 500-550 parts coarse aggregate of carbide steel slag, 800-850 parts fine aggregate of modified steel slag, 3-5 parts basalt fiber, 2-5 parts wollastonite fiber, 2-4 parts nano-carbon fiber, 7-12 parts water-reducing agent, 3-6 parts retarder, and 150-165 parts water. The modified steel slag fine aggregate preparation process is as follows: the steel slag fine aggregate is soaked in saturated lime water for water treatment, and then carbonized to obtain the final product.

2. The high-performance penetration-resistant concrete according to claim 1, characterized in that... The mineral powder is at least one of S95 grade and S105 grade.

3. The high-performance penetration-resistant concrete according to claim 1, characterized in that... The waste nano-ceramic balls are waste grinding media generated during the grinding process of a mill, with a particle size of 5-8 mm.

4. The high-performance penetration-resistant concrete according to claim 1, characterized in that... The carbonized steel slag coarse aggregate is obtained by carbonizing steel slag coarse aggregate, and the particle size of the steel slag coarse aggregate is 5-20mm.

5. The high-performance penetration-resistant concrete according to claim 4, characterized in that... The carbonization process involves carbonizing with CO2-containing gas for 18-36 hours at a pressure of 0.2-0.5 MPa.

6. The high-performance penetration-resistant concrete according to claim 1, characterized in that... In the preparation process of modified steel slag fine aggregate, the particle size of steel slag fine aggregate is 0.5-4.25mm.

7. The high-performance penetration-resistant concrete according to claim 1, characterized in that... The basalt fiber has a length of 3-5 mm, the wollastonite fiber has a length of 0.5-1 mm, and the carbon nanofiber has a diameter of 150-200 nm and a length of 10-20 μm.

8. The high-performance penetration-resistant concrete according to claim 1, characterized in that... The water-reducing agent is a polycarboxylate water-reducing agent.

9. The high-performance penetration-resistant concrete according to claim 1, characterized in that... The retarder is at least one of borax, sodium gluconate, and sucrose.

10. The method for preparing high-performance penetration-resistant concrete according to any one of claims 1-9, characterized in that... It includes the following steps: 1) Weigh each ingredient according to its weight. 2) Mix all ingredients thoroughly. 3) Shape and cure, and you will get the product.