Multi-layer composite high-speed impact damage resistant protective surface and preparation method thereof

Abstract

The invention discloses a multi-layer composite high-speed impact damage resistant protective surface and a preparation method thereof. The protection surface consists of an orthogonal basalt layer, a fiber modified reinforced concrete layer, a polymer composite tough aggregate mortar layer and a rigid supporting layer from an impact surface to the bottom in sequence, wherein the thickness ratio of the orthogonal basalt layer to the fiber modified reinforced concrete layer to the polymer composite tough aggregate mortar layer to the rigid supporting layer is (40-60): (130-170): (290-300): (1-10); basalt plates in the orthogonal basalt layer are laid in a double-layer orthogonal mode at the elevation angle of 10-30 degrees. The protective surface is formed by pouring templates layer by layer and integrally curing, so that the structural characteristics of the layers of the protective surface are greatly reserved while the good combination degree between the layers is ensured, and the technical purpose of multi-structure coupling enhanced wave-absorbing penetration resistance is achieved. Based on the composite structural characteristics of the protective surface, the penetration resistance of the protective surface is improved, the overall structural toughness of the protective surface is remarkably enhanced, stress waves generated by ultra-high-speed impact can be effectively absorbed, cracking fragments caused by excessive deformation of the protective surface are avoided, and secondary damage is avoided.

Description

Technical Field

[0001] The invention relates to a protective surface, in particular to a multi-layer composite protective surface resistant to high-speed impact damage and a preparation method thereof, belonging to the field of ultra-high-speed impact protection. Background Art

[0002] Explosion-proof and bullet-proof materials have important application value in blasting and demolition operation sites, security systems of important institutions, and national defense and military protection facilities. Typical application scenarios include special structural parts such as hole structures, entrance and exit facilities, and shaft devices in underground projects, as well as military strategic targets such as field positions and fortifications. The impact of explosions presents the characteristics of multi-physical field coupling, which is specifically manifested as the combined effect of high-pressure shock waves and high-speed fragments. This type of damage has the characteristics of high destructive strength, wide range of action, and far-reaching subsequent impact. Since the transfer of explosive energy involves the thermal-mechanical-chemical multi-field coupling mechanism, the protection system needs to deal with energy impacts in various forms at the same time, which puts forward multi-dimensional performance requirements for existing impact-proof materials. Concrete has long been widely used in the field of building load-bearing components and impact-resistant protection engineering due to its excellent compressive properties. However, the traditional reinforced concrete system is limited by the material properties, and has inherent defects such as low toughness index, insufficient ductility, and low energy dissipation efficiency. It is difficult to achieve the two functions of shock wave energy absorption and projectile penetration protection, and can no longer meet the growing high-strength composite protection needs of modern protection projects.

[0003] The document "Research on the Penetration and Explosion Resistance of Ultra-High Performance Concrete" used ultra-high performance concrete specimens to conduct penetration resistance tests. Although the ultra-high performance concrete used in the study has significantly improved penetration resistance compared to plain concrete, using only ultra-high performance concrete as a protective material under high-speed impact will lead to structural integrity damage caused by crack expansion.

[0004] The document "Ultra-High Performance Concrete Anti-Penetration Explosion Performance Based on Functional Gradient Principle" further studied the anti-penetration performance of gradient functional concrete structures based on stress wave propagation theory. The study found that compared with a single structure, gradient functional concrete can effectively reduce the penetration depth and damage area so that the overall protection function is still maintained. However, there is no targeted anti-explosion structure design in the gradient functional structure design, and the generated stress waves cannot be effectively absorbed, resulting in secondary killing caused by collapsed fragments. In addition, the buffer layer does not receive sufficient support, which causes excessive deformation of the back under impact, resulting in excessive displacement or delamination, making it difficult to resist multiple blows.

[0005] The document "Anti-penetration test and numerical simulation of multi-layer heterogeneous ceramic composite target plates" studied the influence of low-impedance materials on anti-penetration performance. The study found that low-impedance materials cannot effectively provide sufficient support for the anti-penetration layer to reduce the projectile penetration resistance, which will significantly reduce the anti-penetration performance of the protective structure.

[0006] The patent document (WO2023246417A1) discloses a lightweight bulletproof and explosion-resistant multiphase composite armor material based on a high-toughness heterogeneous interface layer, which uses a gradient functional structure. However, the porous material of the anti-penetration layer has a significantly lower compressive strength than the dense steel fiber concrete material, making it difficult to effectively play the role of the anti-penetration layer. At the same time, the lack of a deflection layer design significantly affects the anti-penetration ability of the protective structure.

[0007] The Chinese patent (CN115468457A) discloses an anti-explosion structure with an anti-penetration layer having a profiled surface, in which a profiled deflector plate design is added on the basis of a gradient functional material. The design of the deflector plate can reduce the penetration depth, increase the penetration path of the projectile, and avoid repeated attacks on the same position. However, the commonly used protruding ball deflector plate has a very limited effective area because the gaps between the protruding balls cannot play a deflection role, and it is difficult to fully exert the projectile deflection effect. Summary of the invention

[0008] In view of the problems existing in the prior art, the first purpose of the present invention is to provide a multi-layer composite protective surface that is resistant to high-speed impact damage. The protective surface is based on the synergy between the various layers of the structure to construct an integrated multi-layer composite structure of deflection, penetration resistance and buffering. On the premise of greatly improving the anti-penetration ability of the protective surface and reducing the penetration depth, it also significantly enhances the overall structural toughness of the protective surface, can effectively absorb the stress waves generated by ultra-high-speed impact, avoid the collapse of fragments caused by excessive deformation of the protective surface, avoid secondary damage, and achieve the effect of resisting multiple strikes.

[0009] The second purpose of the present invention is to provide a method for preparing a multi-layer composite high-speed impact-resistant protective surface. The method adopts a layer-by-layer laying-joint maintenance method, which not only ensures good bonding between the layers, but also largely retains the structural characteristics between the layers of the protective surface, achieving the technical purpose of multi-structure coupling to enhance wave absorption and anti-penetration; the method has the advantages of simple process, convenient operation and low equipment cost, and the molding process is carried out at low temperature and normal pressure, without high temperature, high pressure or vacuum conditions, reducing preparation energy consumption, and is suitable for large-scale industrial production.

[0010] In order to achieve the above technical objectives, the present invention provides a multi-layer composite protective surface that is resistant to high-speed impact damage. The protective surface is composed of an orthogonal basalt layer, a fiber-modified reinforced concrete layer, a polymer composite tough aggregate mortar layer and a rigid support layer in sequence from the impact surface downward, and the thickness ratio of the four is 40~60:130~170:290~300:1~10; the basalt plates in the orthogonal basalt layer are orthogonally laid in double layers at an elevation angle of 10~30°.

[0011] As a preferred solution, 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] In the technical solution provided by the present invention, based on the different structural characteristics of each layer, only by arranging them layer by layer in strict accordance with the above requirements can the technical purpose of multi-structure coupling enhanced protective surface wave absorption and anti-penetration be achieved; at the moment when the protective surface is subjected to high-speed impact, the basalt in the surface layer first realizes energy dissipation through local fragmentation, and its double-layer orthogonal arrangement at a specific elevation angle can play a role in impact deflection, and then the fiber-modified reinforced concrete layer of the second layer plays a role in dissipating the main impact energy through the reinforced fiber, while effectively suppressing the generation of diffuse cracks, it also avoids the local concentration of impact stress in the concrete layer; the third layer of polymer composite tough aggregate mortar layer utilizes the characteristics of polymer material long chain structure to increase flexibility and toughness, and plays a role in flexible buffering and absorption of residual shock waves, and the fourth layer of rigid support layer, while destroying the overall structure, also greatly reduces the deformation of the back of the protective surface, reduces secondary damage, and significantly increases the impact resistance of the protective surface.

[0013] As a preferred solution, the compressive strength of the basalt board is ≥80MPa.

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

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

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

[0017] As a preferred solution, the diameter of the fine steel fiber is 100-300 μm, and the aspect ratio is 50-70. More preferably, the diameter of the fine steel fiber is 200 μm, and the aspect ratio is 65.

[0018] As a preferred solution, the compressive strength of the polymer composite tough aggregate mortar layer is 1.5-3.5 MPa, and the polymer composite tough aggregate is polypropylene fiber-reinforced micro-foam pore-forming rubber particles.

[0019] As a preferred solution, the polymer composite tough aggregate is polypropylene fiber toughened micro-foam porous rubber particles, the aggregate particle size range is 0.3~4.5mm, and is composed of 8~12 parts of polypropylene fiber: 35~45 parts of porous micro-foam: 45~55 parts of rubber fine particles.

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

[0021] As a preferred solution, the thickness of the single steel plate in the double-layer laminated steel plate is 1-5 cm, and the laminate is a 3-10 mm thick silicone adhesive layer. The double-layer laminated steel plate support layer used in the present invention effectively ensures the overall stability and anti-penetration capability of the protective surface structure. In addition, the silicone adhesive layer embedded between the steel plates and the rigid rubber bearings installed at the bottom of both sides of the steel plates can greatly improve the energy absorption capacity of the support layer through viscous energy dissipation, effectively reduce the interlayer deformation generated during the impact of the steel plate, and ensure the structural stability of the support layer.

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

[0023] Step S1, filling a silicone adhesive layer into a double-layer steel plate and installing rigid rubber bearings at the bottom of both sides of the steel plate to obtain a rigid support layer, and then placing a template on the rigid support layer;

[0024] Step S2, mixing the raw materials of the mortar layer including the polymer composite tough aggregate particles and pouring them into the formwork evenly, and vibrating them sufficiently to form a polymer composite tough aggregate mortar layer on the support layer;

[0025] Step S3, mixing the concrete layer raw materials including the reinforcing fiber and the concrete evenly and pouring them into the formwork, and vibrating them sufficiently to form a fiber-modified reinforced concrete layer on the polymer composite tough aggregate mortar layer;

[0026] Step S4, laying the basalt slabs orthogonally in double layers at an elevation angle of 10-30 degrees in the formwork, pouring the emulsified asphalt mortar, and after sufficient vibration to form an orthogonal basalt layer on the fiber-modified reinforced concrete layer, curing is performed.

[0027] As a preferred solution, the raw materials for the mortar layer include the following components in mass parts: 1 part of P.O42.5 cement, 0.6-0.8 parts of water, 0.8-1.2 parts of polymer composite tough aggregate, and 0.3-0.6 parts of river sand. Further preferably, the raw materials for the mortar layer include the following components in mass parts: 1 part of P.O42.5 cement, 0.8 parts of water, 1 part of polymer composite tough aggregate, and 0.5 parts of river sand.

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

[0029] As a preferred solution, the curing conditions are: after construction and forming, immediately cover and wrap for curing for 3 to 5 hours, and then cure for not less than 5 days at 45±5℃ and humidity RH not less than 95%.

[0030] Compared with the prior art, the excellent technical effects of the technical solution of the present invention are:

[0031] 1) The protective surface provided by the present invention is based on the synergistic effect between the various layers of structure to construct an integrated multi-layer composite structure of deflection, anti-penetration and buffering. On the premise of greatly improving the anti-penetration ability of the protective surface and reducing the penetration depth, it also significantly enhances the overall structural toughness of the protective surface, can effectively absorb the stress waves generated by ultra-high-speed impact, avoid the excessive deformation of the protective surface causing fragmentation and secondary damage, and can withstand multiple attacks.

[0032] 2) The preparation method provided by the present invention adopts a layer-by-layer laying-joint maintenance method, which not only ensures good bonding between the layers, but also largely retains the structural characteristics between the layers of the protection 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, thus reducing preparation energy consumption and being suitable for large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of the structure of the protection surface provided in Example 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 pore-forming rubber aggregate mortar layer, 4-double-layer laminated steel plate;

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

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

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

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

[0039] Figure 4 Schematic diagram of orthogonal basalt layers in a multi-layer composite structure resistant to ultra-high-speed impact;

[0040] Among them, 11-emulsified asphalt mortar, 12-basalt blocks with specifications of 20×12×4mm. DETAILED DESCRIPTION

[0041] For ease of understanding of the present invention, the present invention will be described more fully below with reference to specific implementation cases. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments, and are not intended to limit the present invention.

[0042] Example 1

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

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

[0045] Step S2, 1 part of P.O42.5 cement, 0.8 part of water, 1 part of polymer composite toughness aggregate, and 0.5 part of river sand are mixed and poured evenly into a mold, and after sufficient vibration, a 177 mm thick polypropylene fiber toughened micro-foam pore-forming rubber aggregate mortar layer is formed on the support layer;

[0046] Step S3, 700 parts of cement, 150 parts of fly ash, 200 parts of silica fume, 240 parts of steel fiber, 650 parts of river sand, 700 parts of barite aggregate with a particle size of 5-10 mm, 180 parts of water, and 30 parts of polycarboxylic acid water reducer are mixed and poured into the formwork, and after sufficient vibration, a 90 mm thick fine steel fiber reinforced concrete layer is formed on the polypropylene fiber toughened micro-foam pore-forming rubber aggregate mortar layer;

[0047] Step S4, lay basalt slabs with a size of 20×12×4 mm in length, width and height in double layers at an elevation of 20° in the formwork, then pour emulsified asphalt mortar, and after sufficient vibration, form a 30 mm thick orthogonal basalt layer on the fine steel fiber reinforced concrete layer and then perform maintenance to obtain the product.

[0048] The curing conditions are: after construction, immediately cover and wrap for curing for 4 hours, and then cure for not less than 5 days at 45±5℃ and humidity RH not less than 95%.

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

[0050] Comparative Example 1

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

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

Claims

1. A multi-layer composite protective surface resistant to high-speed impact damage, characterized in that: From the impact surface downward, it is composed of orthogonal basalt layer, fiber-modified reinforced concrete layer, polymer composite tough aggregate mortar layer and rigid support layer, and the thickness ratio of the four is 40~60:130~170:290~300:1~10; The basalt plates in the orthogonal basalt layer are orthogonally laid in double layers at an elevation angle of 10-30 degrees.

2. The multi-layer composite high-speed impact resistant protective surface according to claim 1, characterized in that: The compressive strength of the basalt board is ≥80MPa; the binder in the orthogonal basalt layer is an emulsified asphalt mortar with a compressive strength of ≥10MPa, and the thickness of the emulsified asphalt mortar layer is 5-10cm.

3. The multi-layer composite high-speed impact resistant protective surface according to claim 1, characterized in that: 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%; the diameter of the fine steel fiber is 100-300μm, and the aspect ratio is 50-70.

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

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

6. The method for preparing a multi-layer composite high-speed impact resistant protective surface according to any one of claims 1 to 5, characterized in that: include: Step S1: Fill the double-layer steel plate with a silicone adhesive layer and install rigid rubber supports at the bottom of both sides of the steel plate to obtain a rigid support layer, and then set a template on the support layer. Step S2, mixing the raw materials for the mortar layer including the polymer composite tough aggregate and pouring them into the formwork evenly, and vibrating them sufficiently to form a polymer composite tough aggregate mortar layer on the support layer; Step S3, mixing the concrete layer raw materials including the reinforcing fiber and the concrete evenly and pouring them into the formwork, and vibrating them sufficiently to form a fiber-modified reinforced concrete layer on the polymer composite tough aggregate mortar layer; Step S4, laying the basalt slabs orthogonally in double layers at an elevation angle of 10-30 degrees in the formwork, pouring the emulsified asphalt mortar, and after sufficient vibration to form an orthogonal basalt layer on the fiber-modified reinforced concrete layer, curing is performed.

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

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

9. The method for preparing a multi-layer composite high-speed impact resistant protective surface according to claim 6, characterized in that: The curing conditions are as follows: after construction, immediately cover and wrap for curing for 3 to 5 hours, and then cure at 45±5℃ with humidity RH not less than 95% for not less than 5 days.

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