Multilayer composite protective face resistant to high speed impact damage and method of making same

Abstract

The application discloses a multilayer composite protection surface resisting high-speed impact damage and a preparation method thereof. The protection surface is composed of an orthogonal basalt layer, a fiber modified reinforced concrete layer, a polymer composite toughness aggregate mortar layer and a steel support layer from the impact surface downwards, and the thickness ratio of the four layers is 40-60:130-170:290-300:1-10. Basalt plates in the orthogonal basalt layer are double-layered and orthogonally laid at an elevation angle of 10-30 degrees. The protection surface is poured layer by layer by using a template, and is integrally cured and formed, so that the structural characteristics between the layers of the protection surface are greatly reserved while good combination between the layers is ensured, the technical purpose of multi-structure coupling strengthening wave absorption and penetration resistance is achieved. Based on the composite structural characteristics of the protection surface, the penetration resistance of the protection surface is improved, the overall structural toughness of the protection surface is significantly strengthened, stress waves generated by super-high-speed impact can be effectively absorbed, collapse and fragmentation caused by excessive deformation of the protection surface can be avoided, and secondary injury can be avoided.

Description

Technical Field

[0001] This invention relates to a protective surface, specifically a multi-layered composite protective surface resistant to high-speed impact damage and its preparation method, belonging to the field of ultra-high-speed impact protection. Background Technology

[0002] Explosion-proof and bulletproof materials have significant application value in demolition sites, security systems of important institutions, and national defense and military protection facilities. Typical applications include special structural parts such as underground engineering openings, entrances and exits, and shaft installations, as well as military strategic targets such as field fortifications. Explosive impacts exhibit multi-physics field coupling characteristics, specifically the combined effect of high-pressure shock waves and high-speed fragments. This type of damage is characterized by high destructive strength, wide impact range, and far-reaching subsequent effects. Because the energy transfer of an explosion involves a multi-field coupling mechanism of thermo-mechanical-chemical fields, protective systems must simultaneously cope with various forms of energy impact, posing multi-dimensional performance requirements for existing impact-resistant materials. Concrete, with its excellent compressive strength, has long been widely used in building load-bearing components and impact protection engineering. However, traditional reinforced concrete systems are limited by material properties, exhibiting inherent defects such as low toughness index, insufficient ductility, and low energy dissipation efficiency. This makes it difficult to achieve both shock wave energy absorption and projectile penetration protection, and it can no longer meet the growing demand for high-strength composite protection in modern engineering.

[0003] The literature “Research on Penetration Resistance and Explosion Resistance of Ultra-High Performance Concrete” conducted penetration resistance tests using ultra-high performance concrete specimens. Although the ultra-high performance concrete used in the study significantly improved the penetration resistance compared to plain concrete, using only ultra-high performance concrete as a protective material under high-speed impact would lead to crack propagation and structural damage.

[0004] The paper "Penetration Resistance of Ultra-High Performance Concrete Based on Functional Gradient Principle" further investigated the penetration resistance of functionally graded concrete structures based on stress wave propagation theory. The study found that compared to single-structure structures, functionally graded concrete can effectively reduce penetration depth and damage area while maintaining overall protective function. However, the lack of specific blast-resistant design in the functionally graded structure meant that the generated stress waves could not be effectively absorbed, leading to fragmentation and secondary damage. Furthermore, the insufficient support of the buffer layer resulted in excessive deformation on the back side under impact, causing excessive displacement or delamination, making it difficult to withstand multiple impacts.

[0005] The literature "Penetration Resistance Test and Numerical Simulation of Multilayer Heterogeneous Ceramic Composite Target Plate" studied the influence of low-impedance materials on penetration resistance. The study found that low-impedance materials cannot effectively provide sufficient support for the penetration resistance layer to reduce the penetration resistance of the projectile, which will significantly reduce the penetration resistance of the protective structure.

[0006] Patent document (WO2023246417A1) discloses a lightweight bulletproof and blast-resistant multiphase composite armor material based on a high-toughness heterogeneous interface layer, which employs a gradient functional structure. However, compared to dense steel fiber reinforced concrete, the porous material of the penetration-resistant layer has significantly lower compressive strength, making it difficult to effectively perform the function of the penetration-resistant layer. Furthermore, the lack of a biased elastic layer design significantly affects the penetration resistance of the protective structure.

[0007] Chinese patent (CN115468457A) discloses an anti-explosion structure with an irregularly shaped surface anti-penetration layer, which adds an irregularly shaped deflector plate design to the base material of a graded functional material. The deflector plate design can reduce the penetration depth, increase the penetration path of the projectile, and prevent repeated impacts on the same location. However, this commonly used protruding ball deflector plate has a limited effective area because the gaps between the protruding balls cannot play a deflecting role, making it difficult to fully realize the projectile deflection effect. Summary of the Invention

[0008] To address the problems existing in the prior art, the first objective of this invention is to provide a multi-layered composite protective surface resistant to high-speed impact damage. This protective surface, based on the synergistic effect between its various layers, constructs an integrated multi-layered composite structure of elasticity, penetration resistance, and buffering. While significantly improving the surface's penetration resistance and reducing penetration depth, it also significantly enhances the overall structural toughness of the protective surface. This effectively absorbs stress waves generated by ultra-high-speed impacts, preventing excessive deformation of the protective surface from causing fragmentation, avoiding secondary damage, and achieving the ability to withstand multiple impacts.

[0009] The second objective of this invention is to provide a method for preparing a multi-layered composite protective surface resistant to high-speed impact damage. This method employs a layer-by-layer laying and co-curing approach, ensuring good bonding between layers while significantly preserving the structural characteristics of each layer of the protective surface, achieving the technical objective of multi-structure coupling to enhance wave absorption and anti-penetration. This method has advantages such as simple process, convenient operation, and low equipment cost. The molding process is carried out at low temperature and normal pressure, eliminating the need for high temperature, high pressure, or vacuum conditions, reducing energy consumption and making it suitable for large-scale industrial production.

[0010] To achieve the above-mentioned technical objectives, the present invention provides a multi-layered composite protective surface resistant to high-speed impact damage. The protective surface consists of, from the impact surface downwards, an orthogonal basalt layer, a fiber-modified reinforced concrete layer, a polymer composite tough aggregate mortar layer, and a rigid support layer, with the thickness ratio of the four layers being 40~60:130~170:290~300:1~10; the basalt slabs in the orthogonal basalt layer are laid in two orthogonal layers at an elevation angle of 10~30°.

[0011] As a preferred embodiment, the thickness ratio of the orthogonal basalt layer, the fiber-modified reinforced concrete layer, the polymer composite tough aggregate mortar layer, and the rigid support layer is 50:150:295:5.

[0012] The technical solution provided by this invention, based on the different structural characteristics of each layer, requires strict adherence to the above requirements for layer-by-layer arrangement to achieve the technical objective of multi-structure coupling to strengthen the protective surface and resist wave penetration. At the moment the protective surface is subjected to a high-speed impact, the basalt of the surface layer first dissipates energy through localized fragmentation. Its double-layer orthogonal arrangement at a specific elevation angle can deflect the impact. Then, the second layer, fiber-modified reinforced concrete, dissipates the main impact energy through reinforcing fibers, effectively suppressing the generation of diffuse cracks while preventing localized concentration of impact stress in the concrete layer. The third layer, a high-polymer composite tough aggregate mortar layer, utilizes the flexibility and toughness of the long-chain structure of polymer materials to provide flexible buffering and absorb residual shock waves. The fourth layer, a rigid support layer, while disrupting the overall structure, significantly reduces deformation on the back of the protective surface, minimizing secondary damage and significantly increasing the surface's impact resistance.

[0013] As a preferred embodiment, the basalt slab has a compressive strength ≥80MPa.

[0014] As a preferred embodiment, the binder in the orthogonal basalt layer is an emulsified asphalt mortar with a compressive strength ≥10MPa.

[0015] As a preferred embodiment, the thickness of the emulsified asphalt mortar is 5~10cm.

[0016] As a preferred embodiment, the compressive strength of the fiber-modified reinforced concrete layer is ≥120MPa, and the modified fiber is fine steel fiber, with an addition amount of 1~5%. More preferably, the addition amount of the fine steel fiber is 3%.

[0017] As a preferred embodiment, the diameter of the microfiber is 100~300μm and the aspect ratio is 50~70. More preferably, the diameter of the microfiber is 200μm and the aspect ratio is 65.

[0018] As a preferred embodiment, the compressive strength of the polymer composite tough aggregate mortar layer is 1.5~3.5MPa, and the polymer composite tough aggregate is polypropylene fiber-reinforced microporous rubber particles.

[0019] As a preferred embodiment, the polymer composite tough aggregate is polypropylene fiber-reinforced microporous rubber particles with a particle size range of 0.3~4.5mm, consisting of 8~12 parts polypropylene fiber, 35~45 parts porous microporous particles, and 45~55 parts fine rubber particles.

[0020] As a preferred embodiment, the rigid support layer is a double-layered laminated steel plate with a yield strength ≥500MPa.

[0021] As a preferred embodiment, the thickness of each single-layer steel plate in the double-layer laminated steel plate is 1-5 cm, and the lamination is a 3-10 mm thick silicone adhesive layer. The double-layer laminated steel plate support layer used in this invention effectively ensures the overall stability and penetration resistance of the protective surface structure. Furthermore, the silicone adhesive layer embedded between the steel plates and the rigid rubber supports installed at the bottom of both sides of the steel plates significantly improve the energy absorption capacity of the support layer through viscous energy dissipation, effectively reducing interlayer deformation during impact and ensuring the structural stability of the support layer.

[0022] This invention also provides a method for preparing a multi-layer composite protective surface resistant to high-speed impact damage, comprising:

[0023] Step S1: Fill the double-layer steel plate with silicone adhesive and install rigid rubber supports on both sides of the bottom of the steel plate to obtain a rigid support layer, and then put the template on the rigid support layer.

[0024] Step S2: Mix the mortar layer raw materials, including high-polymer composite tough aggregate particles, evenly and pour them into the template. After thorough vibration, a high-polymer composite tough aggregate mortar layer is formed on the support layer.

[0025] Step S3: Mix the concrete layer raw materials, including reinforcing fibers and concrete, evenly and pour them into the formwork. After thorough vibration, a fiber-modified reinforced concrete layer is formed on the polymer composite tough aggregate mortar layer.

[0026] Step S4: Lay the basalt slabs in two orthogonal layers at an elevation angle of 10-30° in the template, then pour emulsified asphalt mortar, and after thorough vibration, form an orthogonal basalt layer on the fiber-modified reinforced concrete layer, and then cure it.

[0027] As a preferred embodiment, the mortar layer raw materials comprise the following parts by weight: 1 part P.O42.5 cement, 0.6-0.8 parts water, 0.8-1.2 parts high-polymer composite toughening aggregate, and 0.3-0.6 parts river sand. More preferably, the mortar layer raw materials comprise the following parts by weight: 1 part P.O42.5 cement, 0.8 parts water, 1 part high-polymer composite toughening aggregate, and 0.5 parts river sand.

[0028] As a preferred embodiment, the concrete layer raw materials comprise the following parts by weight: 650-750 parts cement, 120-170 parts fly ash, 180-220 parts silica fume, 220-260 parts steel fiber, 600-700 parts river sand, 650-750 parts barite aggregate with a particle size of 5-10 mm, 160-200 parts water, and 20-50 parts polycarboxylate superplasticizer. More preferably, the concrete layer raw materials comprise the following parts by weight: 700 parts cement, 150 parts fly ash, 200 parts silica fume, 240 parts steel fiber, 650 parts river sand, 700 parts barite aggregate with a particle size of 5-10 mm, 180 parts water, and 30 parts polycarboxylate superplasticizer.

[0029] As a preferred option, the curing conditions are as follows: after construction and shaping, immediately cover and wrap for curing for 3 to 5 hours, and then cure for no less than 5 days at 45±5℃ and RH of not less than 95%.

[0030] Compared with the prior art, the superior technical effects of the present invention are as follows:

[0031] 1) The protective surface provided by the present invention is based on the synergistic effect between the layers of the structure to construct an integrated multi-layer composite structure of elasticity, penetration resistance and buffer. While greatly improving the penetration resistance of the protective surface and reducing the penetration depth, it also significantly enhances the overall structural toughness of the protective surface. It can effectively absorb the stress waves generated by ultra-high speed impact, avoid the secondary damage caused by excessive deformation of the protective surface leading to fragmentation, and withstand multiple impacts.

[0032] 2) The preparation method provided by this invention adopts a layer-by-layer laying-co-curing method, which ensures good bonding between each layer while also preserving the structural characteristics between each layer of the protective surface, thereby achieving the technical purpose of multi-structure coupling to enhance wave absorption and anti-penetration. This method has the advantages of simple process, convenient operation and low equipment cost. The molding process is carried out at low temperature and normal pressure, without the need for high temperature, high pressure or vacuum conditions, reducing the energy consumption of preparation and making it suitable for large-scale industrial production. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of the protective surface provided in Embodiment 1 of the present invention;

[0034] Among them, 1-orthogonal basalt layer, 2-fine steel fiber reinforced concrete layer, 3-polypropylene fiber toughened micro-foam porous rubber aggregate mortar layer, 4-double-layer laminated steel plate.

[0035] Figure 2 This is a cross-sectional schematic diagram of the protective surface provided in Comparative Example 1 of the present invention;

[0036] Among them, 5-mixed fiber concrete layer, 6-coarse aggregate steel fiber concrete layer, 7-steel fiber concrete layer;

[0037] Figure 3 This is a schematic diagram of the double-layer laminated steel plate support layer for the protective surface provided in Embodiment 1 of the present invention;

[0038] Among them, 8-single-layer steel plate, 9-rigid rubber support, 10-silicone adhesive layer;

[0039] Figure 4 A schematic diagram of orthogonal basalt layers in a multilayer composite material structure designed to withstand ultra-high-speed impacts;

[0040] Among them, 11-emulsified asphalt mortar, 12-basalt block with a size of 20×12×4mm. Detailed Implementation

[0041] To facilitate understanding of the present invention, a more comprehensive description will be given below with reference to specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of the present invention is for the purpose of describing particular embodiments only and is not intended to limit the invention.

[0042] Example 1

[0043] This embodiment provides a multi-layered composite protective surface resistant to high-speed impact damage, the structure of which is as follows: Figure 1 As shown, from top to bottom, the structure consists of an orthogonal basalt layer, a micro-fiber reinforced concrete layer, a polypropylene fiber toughened micro-foam porous rubber aggregate mortar layer, and a double-layer laminated steel plate. The specific preparation process is as follows:

[0044] Step S1: Fill a double-layer steel plate with a single layer thickness of 1.2mm with a 0.6mm silicone adhesive layer to obtain a support layer, and then fit the support layer onto the plate. PVC pipe template with a diameter of mm, with rigid rubber supports installed at the bottom of the support layer;

[0045] Step S2: Mix 1 part P.O42.5 cement, 0.8 parts water, 1 part high-molecular composite toughness aggregate, and 0.5 parts river sand evenly and pour the mixture into a mold. After thorough vibration, a 177mm thick polypropylene fiber toughened micro-foam porous rubber aggregate mortar layer is formed on the support layer.

[0046] Step S3: Mix 700 parts cement, 150 parts fly ash, 200 parts silica fume, 240 parts steel fiber, 650 parts river sand, 700 parts barite aggregate with a particle size of 5-10mm, 180 parts water, and 30 parts polycarboxylate superplasticizer evenly and pour the mixture into a formwork. After thorough vibration, a 90mm thick layer of fine steel fiber reinforced concrete is formed on the polypropylene fiber toughened microporous rubber aggregate mortar layer.

[0047] Step S4: Lay basalt slabs with dimensions of 20×12×4mm in two orthogonal layers at a 20° elevation angle in the template, then pour emulsified asphalt mortar, and after thorough vibration, form a 30mm thick orthogonal basalt layer on the micro-fiber reinforced concrete layer, and then cure it to obtain the final product.

[0048] The curing conditions are as follows: after construction and shaping, immediately cover and wrap for curing for 4 hours, and then cure for no less than 5 days at 45±5℃ and RH not less than 95%.

[0049] The present invention also conducted performance tests on the protective surface obtained in the above embodiments. The penetrating projectile was a 20mm diameter 35CrMnSi projectile with a firing velocity of 1290m / s. The test results showed that the penetration depth of the protective surface was 62.4mm, and the support layer showed no back-concave deformation.

[0050] Comparative Example 1

[0051] This comparative example is exactly the same as Example 1, except that it consists of a hybrid fiber concrete layer, a coarse aggregate steel fiber concrete layer, and a steel fiber concrete layer from top to bottom.

[0052] The present invention also conducted performance tests on the protective surface obtained in the comparative example above. The penetrating projectile used was a 35CrMnSi projectile with a diameter of 20mm and a firing velocity of 1290m / s. The test results showed that the penetration depth of the protective surface was 81.6mm, and the support layer underwent slight deformation.

Claims

1. A multi-layered composite protective surface resistant to high-speed impact damage, characterized in that: From the impact surface downwards, the structure consists of an orthogonal basalt layer, a fiber-modified reinforced concrete layer, a polymer composite tough aggregate mortar layer, and a rigid support layer, with a thickness ratio of 40~60:130~170:290~300:1~10; the basalt slabs in the orthogonal basalt layer are laid in two orthogonal layers at an elevation angle of 10~30°. The binder in the orthogonal basalt layer is emulsified asphalt mortar; The modified fibers in the fiber-modified reinforced concrete layer are micro-fine steel fibers; The aggregate in the polymer composite tough aggregate mortar layer is polypropylene fiber-reinforced microporous rubber particles; the high-rigidity support layer is a double-layer laminated steel plate.

2. The multi-layer composite protective surface against high-speed impact damage according to claim 1, characterized in that: The basalt slab has a compressive strength ≥80MPa; the emulsified asphalt mortar in the orthogonal basalt layer has a compressive strength ≥10MPa and a thickness of 5~10cm.

3. The multi-layer composite protective surface against high-speed impact damage according to claim 1, characterized in that: The compressive strength of the fiber-modified reinforced concrete layer is ≥120MPa, and the amount of fine steel fiber added is 1~5%; the diameter of the fine steel fiber is 100~300μm, and the aspect ratio is 50~70.

4. The multi-layer composite protective surface against high-speed impact damage according to claim 1, characterized in that: The compressive strength of the polymer composite tough aggregate mortar layer is 1.5~3.5MPa, the aggregate particle size range is 0.3~4.5mm, and it is composed of 8~12 parts polypropylene fiber, 35~45 parts porous microparticles, and 45~55 parts rubber fine particles.

5. The multi-layer composite protective surface against high-speed impact damage according to claim 1, characterized in that: The yield strength of the high-rigidity support layer is ≥500MPa; the thickness of the single-layer steel plate in the double-layer laminated steel plate is 1~5cm, the lamination is a silicone adhesive layer of 3~10mm thickness, and rigid rubber supports are installed on both sides of the bottom of the steel plate.

6. A method for preparing a multi-layer composite protective surface resistant to high-speed impact damage as described in any one of claims 1 to 5, characterized in that, include: Step S1: Fill the double-layer steel plate with silicone adhesive and install rigid rubber supports on both sides of the bottom of the steel plate to obtain a rigid support layer, and then install a template on the support layer. Step S2: Mix the mortar layer raw materials, including high polymer composite tough aggregate, evenly and pour them into the template. After thorough vibration, a high polymer composite tough aggregate mortar layer is formed on the support layer. Step S3: Mix the concrete layer raw materials, including reinforcing fibers and concrete, evenly and pour them into the formwork. After thorough vibration, a fiber-modified reinforced concrete layer is formed on the polymer composite tough aggregate mortar layer. Step S4: Lay the basalt slabs in two orthogonal layers at an elevation angle of 10-30° in the template, then pour emulsified asphalt mortar, and after thorough vibration, form an orthogonal basalt layer on the fiber-modified reinforced concrete layer, and then cure it.

7. The method for preparing a multi-layer composite protective surface resistant to high-speed impact damage according to claim 6, characterized in that: The raw materials of the polymer composite tough aggregate mortar layer include the following components by weight: 1 part P.O42.5 cement, 0.6~0.8 parts water, 0.8~1.2 parts polymer composite tough aggregate, and 0.3~0.6 parts river sand.

8. The method for preparing a multi-layer composite protective surface resistant to high-speed impact damage according to claim 6, characterized in that: The raw materials for the concrete layer include the following components by weight: 650-750 parts cement, 120-170 parts fly ash, 180-220 parts silica fume, 220-260 parts steel fiber, 600-700 parts river sand, 650-750 parts barite aggregate with a particle size of 5-10mm, 160-200 parts water, and 20-50 parts polycarboxylate superplasticizer.

9. The method for preparing a multi-layer composite protective surface resistant to high-speed impact damage according to claim 6, characterized in that: The curing conditions are as follows: after construction and shaping, immediately cover and wrap for curing for 3-5 hours, and then cure for no less than 5 days at 45±5℃ and RH not less than 95%.

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