Composite multi-layer polyurea concrete protection structure resistant to strong impact

Abstract

The invention belongs to the field of protective engineering, and particularly relates to a composite multi-layer polyurea concrete protective structure resistant to strong impact. Comprising a concrete layer I, a bearing plate made of high-strength steel, a concrete layer II and a polyurea coating which are sequentially arranged, wherein the concrete layer I is an explosion facing surface; a W-shaped array support made of steel bars is poured in the concrete I layer, a plurality of bonding holes are arrayed in the force bearing plate, and two inflection points of the bottom of each W-shaped unit of the W-shaped array support abut against the outsides of the bonding holes of the force bearing plate. A composite reinforcing rib frame is poured in the concrete layer II, and composite reinforcing ribs forming the composite reinforcing rib frame are composed of metal round pipes, glass fiber rods arranged in the metal round pipes and metal round pieces at the two ends of the metal round pipes. And cross points of the composite reinforcing ribs are connected by spot welding. According to the invention, firepower strike of enemies can be effectively resisted, and secondary damage caused by scattering of concrete broken stones can be effectively prevented; due to the modular design, replacement can be facilitated, and repair after strong impact damage is easy.

Description

Technical Field

[0001] The invention belongs to the field of protective engineering, and in particular relates to a composite multi-layer polyurea concrete protective structure resistant to strong impact. Background Art

[0002] In order to resist the enemy's firepower attack and protect the safety of facilities and personnel, fortifications play an extremely important role. Today's fortifications are mostly concrete structures. The strong impact formed by artillery shells, rockets, etc. is the main means of attacking fortifications. It not only contains high-temperature and high-pressure shock waves, but also contains explosion products such as fragments. After the impact damage, high-speed concrete fragments are formed, which also cause damage to the equipment and personnel inside the fortifications. Therefore, a highly protected and effective fortification that can resist strong impacts can greatly reduce the killing efficiency of the enemy's firepower and improve our sustained combat capability.

[0003] At present, the concrete structure of the protective fortification follows the structural design of civil houses and bridges, and is built by matching steel bars and concrete. This protective structure has the following defects:

[0004] (1) Low protection capability. The design strength of reinforced concrete is low and it is difficult to resist enemy fire. Increasing the thickness will greatly increase the construction difficulty, time and cost.

[0005] (2) Destruction produces debris. Concrete is a brittle material. After being damaged by fire, it produces high-speed debris, causing secondary damage to equipment and personnel in the fortifications.

[0006] (3) It is difficult to repair after damage. Because concrete is heavy and is cast in one piece, it is difficult to repair quickly and effectively.

[0007] In summary, the existing reinforced concrete fortifications have the disadvantages of low protection capabilities, secondary debris generation and difficulty in repair, and cannot effectively protect the safety of our facilities and personnel. Summary of the invention

[0008] The purpose of the present invention is to provide a composite multi-layer polyurea concrete protective structure resistant to strong impact.

[0009] The technical solution to achieve the purpose of the present invention is: a composite multi-layer polyurea concrete protective structure resistant to strong impact, comprising a concrete layer I, a bearing plate made of high-strength steel, a concrete layer II and a polyurea coating arranged in sequence, wherein the concrete layer I is the explosion-facing surface;

[0010] A W-shaped array bracket made of steel bars is cast in the concrete layer I, and a plurality of bonding holes are arrayed on the load-bearing plate. The two inflection points at the bottom of each W-shaped unit of the W-shaped array bracket are arranged outside the bonding holes of the load-bearing plate; a composite reinforcement rib frame is cast in the concrete layer II, and the composite reinforcement ribs constituting the composite reinforcement rib frame are composed of a metal round tube, a glass fiber rod arranged in the metal round tube, and metal discs at both ends of the metal round tube; the intersections of the composite reinforcement ribs are connected by spot welding.

[0011] Furthermore, the W-shaped array bracket is composed of multiple groups of reinforcing ribs arranged in a criss-cross manner, each group of reinforcing ribs includes multiple W-shaped units extending in one direction, and each of the top two ends of the W-shaped unit is provided with extension parts extending outward, and the two adjacent W-shaped units are welded into one body through the extension parts, and the connection parts of the extension parts are welded to the connection parts of the extension parts of another group of reinforcing ribs arranged orthogonally, and the middle inflection point of the W-shaped unit is welded to the orthogonally arranged connecting steel bars.

[0012] Furthermore, the thickness of the concrete protective structure is H0, the length and width are both L0, the thickness of the concrete layer I is H1, the height of the concrete layer II is H1, the height of the W-shaped array bracket, that is, the height of the W-shaped unit is h1, the bending height of the W-shaped unit is h2, the bending angle of the bending position of the W-shaped unit is 60°, the length of the W-shaped unit is 2b1, and the length of the W-shaped unit from the outermost end of the extension part on one side to the corresponding side inflection point at the bottom is b2; the size of the W-shaped unit satisfies the following formula:

[0013]

[0014] b2=tan 30°*h1

[0015] b1-b2=tan 30°*(h1-h2)

[0016]

[0017] The thickness H1 of concrete layer I satisfies the following formula:

[0018] H1≥h1+20mm

[0019]

[0020] Furthermore, the yield strength of the steel bars used in the W-shaped array bracket is not less than 500 MPa, and the tensile strength is not less than 630 MPa.

[0021] Furthermore, the composite reinforcement ribs of the composite reinforcement rib frame are arranged in two layers, each layer is arranged in a crisscross pattern, the two layers of composite reinforcement ribs are connected by composite reinforcement ribs, and the intersections are welded; the height of the composite reinforcement rib frame is f1, the distribution width is f2, and the following requirements are met:

[0022] f1=(H2-20) / 2

[0023] f2=(L0-40) / 9.

[0024] Furthermore, the diameter of the glass fiber rod is equal to the inner diameter of the metal tube and is not less than 6 mm; the glass fiber rod is made of 60 ± 10 fiber bundles wound and woven, and the density of each fiber bundle is not less than 2.45 g / cm 3 , tensile strength is not less than 919MPa, Young's modulus is not less than 113MPa, and elongation is not less than 1.5%; the metal round tube is made of Q235, with an outer diameter of 8mm-10mm and a wall thickness of not less than 1mm.

[0025] Furthermore, the material of the bearing plate is Q960E, the yield strength is not less than 960MPa, the thickness is not less than 5mm, the diameter of the bonding hole of the bearing plate is not less than 140mm, the distance between the center of the edge bonding hole and the edge of the bearing plate is c1 and d1, the longitudinal and transverse hole spacing is c2 and d2, and meets the following requirements:

[0026] c1=d1

[0027] c2=d2=(L0-2c1-r-40) / 8.

[0028] Furthermore, the polyurea coating is applied to the concrete surface using static mixing spraying equipment, with a thickness of not less than 5 mm, a yield strength of not less than 17.8 MPa, a fracture strength of not less than 36 MPa, and an elongation of not less than 340%.

[0029] Furthermore, the concrete grade of the first layer of concrete used in concrete layer I and concrete layer II shall not be lower than C40, the cement strength grade shall not be lower than 42.5, and the coarse sand ratio shall not be lower than 37%.

[0030] Furthermore, nuts are embedded in the concrete protective structure for connection with the fortification skeleton bolts.

[0031] Compared with the prior art, the present invention has the following significant advantages:

[0032] 1. The invention provides a composite multi-layer polyurea concrete protective structure resistant to strong impact, which can effectively resist enemy fire attack, and comprises two layers, the first layer is used to disperse strong impact, and the second layer is used to resist strong impact;

[0033] 2. The present invention provides a composite multi-layer polyurea concrete protective structure resistant to strong impact, with a load-bearing plate in the middle and a polyurea coating on the back. The load-bearing plate disperses the impact force and enhances the overall rigidity, as well as the flexibility of the polyurea coating, which can effectively prevent secondary damage caused by the flying of concrete gravel;

[0034] 3. The invention provides a composite multi-layer polyurea concrete protective structure resistant to strong impacts. The overall structure is a flat plate structure with a modular design, which can be easily replaced and repaired after being damaged by strong impacts. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is an overall schematic diagram of the composite multi-layer polyurea concrete protective structure of the present invention; wherein (a) is a three-dimensional diagram, (b) is a main view, and (c) is a frame schematic diagram.

[0036] Figure 2 Schematic diagram of the W-shaped array bracket of the present invention; wherein (a) is a three-dimensional diagram, (b) is a schematic diagram of the W-shaped unit, and (c) is a main view.

[0037] Figure 3 It is a schematic diagram of the bearing plate of the present invention.

[0038] Figure 4 Schematic diagram of the composite reinforcing rib frame of the present invention; wherein (a) is a three-dimensional diagram, (b) is a top view, (c) is a reinforcing rib cross-sectional view, and (d) is a main view.

[0039] Description of reference numerals:

[0040] 1-concrete layer I, 2-W-shaped array bracket, 3-load-bearing plate, 4-concrete layer II, 5-composite reinforcement frame, 6-polyurea coating, 7-glass fiber rod, 8-metal round tube. DETAILED DESCRIPTION

[0041] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0042] like Figure 1-4 As shown, the present invention provides a composite multi-layer polyurea concrete protective structure resistant to strong impact, comprising a protective matrix and a functional layer;

[0043] The protective matrix includes a concrete layer Ⅰ 1 for direct resistance to fire attack and a concrete layer Ⅱ 4 for strength support and rubble protection;

[0044] The functional layer includes a W-shaped array bracket 2, a load-bearing plate 3, a composite reinforcement rib frame 5 and a polyurea coating 6.

[0045] The thickness of the concrete protection structure is H0, and the length and width are both L0;

[0046] The concrete layer I is cast integrally with the concrete and the W-shaped array bracket 2, and the thickness of the concrete above and below the W-shaped array bracket 2 is not less than 10 mm;

[0047] The W-shaped array bracket 2 plays a role in strengthening the first layer of the matrix and dispersing the force. The steel bar is made into a "W" shape through a bending process, and the impact force is evenly dispersed to the entire first layer through the "W" structure; the material of the W-shaped array bracket 2 is steel bar, and the grade is preferably HRB500, with a yield strength of not less than 500MPa and a tensile strength of not less than 630MPa; Figure 2 As shown, the height is h1 and the length is 2b1. The bending angles of the bending positions b, c, and d are all 60°, which realizes the effective and stable transmission of the impact force. Nine "M"-shaped brackets are set in the vertical and horizontal directions of the concrete. It can be seen from the concrete length L0 that:

[0048]

[0049] The relationship of setting the bending height of the "W" type is as follows:

[0050]

[0051] The calculation can be obtained:

[0052] b2=tan 30°*h1

[0053] b1-b2=tan 30°*(h1-h2)

[0054]

[0055] It can be seen that the total height of the W-shaped array bracket is h1, and the height from the middle corner to the bottom is 2 / 3h1.

[0056] It can be seen that the thickness of concrete layer I is H1:

[0057] H1≥h1+20mm

[0058]

[0059] The concrete grade of concrete used for concrete layer I shall not be lower than C40, the cement strength grade shall not be lower than 42.5, and the coarse sand ratio shall not be lower than 37%.

[0060] The concrete layer II is cast by concrete and composite reinforcement. The thickness of the concrete layer II is H2.

[0061] H2=H0-H1

[0062]

[0063] The composite reinforcement ribs of the composite reinforcement rib frame 5 are composed of glass fiber rods 7 and metal round tubes 8, which have the hard and brittle characteristics of glass fiber and the flexibility of metal round tubes. The cylindrical glass fiber rods 7 are placed inside the metal round tubes 8, and the two ends are welded and sealed with metal discs. The diameter of the glass fiber rods 7 is not less than 6mm; the glass fiber rods 7 are made of 60 fiber bundles twisted and woven, and the density of each fiber bundle is not less than 2.45g / cm 3 , tensile strength is not less than 919MPa, Young's modulus is not less than 113MPa, and elongation is not less than 1.5%; the metal round tube 8 is made of Q235, with an outer diameter of 8mm-10mm and a wall thickness of not less than 1mm.

[0064] The composite reinforcement is set to two layers, upper and lower, with longitudinal composite reinforcement set between the two layers, spot welded at the cross position, with a height of f1 and a distribution width of f2, meeting the following requirements:

[0065] f1=(H2-20) / 2

[0066] f2=(L0-40) / 9

[0067] The concrete requirements in concrete layer II are the same as those in concrete layer I;

[0068] The material of the bearing plate 3 is Q960E, the yield strength is not less than 960MPa, the thickness is not less than 5mm, and the bonding holes with a diameter of r and not less than 140mm are evenly arranged on the bearing plate. The bearing plate 3 can disperse the impact force transmitted by the first layer, evenly transmit the impact force to the second layer of concrete, and block the splash of the first layer of gravel, increase the bonding strength of the first and second layers of concrete, and reduce the weight of the bearing plate.

[0069] like Figure 3 As shown, the distance between the center of the first hole and the edge of the bearing plate is c1 and d1, the longitudinal and transverse hole spacing is c2 and d2, and the following requirements are met:

[0070] c1=d1

[0071] c2=d2=(L0-2c1-r-40) / 8

[0072] The polyurea coating is an explosion-proof coating with a yield strength of not less than 17.8MPa, a breaking strength of not less than 36MPa, and an elongation of not less than 340%. It is applied to the concrete surface using static mixing spraying equipment with a thickness of not less than 5mm.

[0073] The load-bearing plate 3 is ensured to be placed in the center; the poured concrete structure is steam-cured, and after being removed from the mold, water is sprinkled to keep it moist and naturally cured.

[0074] Example

[0075] like Figure 1-4As shown, a composite multi-layer polyurea concrete protective structure resistant to strong impact includes a protective matrix and a functional layer. The protective matrix includes a concrete layer I and a concrete layer II. The concrete layer I 1 and the W-shaped array bracket 2 are cast as a whole. The thickness of the concrete layer I 1 is 125 mm. It serves as the front layer of the entire protective structure and is used to directly resist strong impact and disperse strong impact force. The concrete layer II 4 and the composite reinforcement frame 5 are cast as a whole. The thickness of the concrete layer II 4 is 100 mm. It serves as the back layer of the entire protective structure and is used to indirectly resist strong impact, reduce deformation, and prevent the impact of gravel.

[0076] The functional layer includes a W-shaped array bracket 2, a bearing plate 3, a composite reinforcement frame 5 and a polyurea coating 6. The W-shaped array bracket 2 enhances the strength of the concrete layer I 1, and the top of the W-shaped array bracket 2 faces the explosion-facing surface; the W-shaped array bracket 2 is arranged in a criss-cross pattern, with an evenly arranged spacing of 181.69 mm, 9 in each of the longitudinal and transverse directions, and the intersections are spot welded; a connecting steel bar with a diameter of 5 mm is arranged at the bending angle c of the W-shaped array bracket 2, which is spot welded with the W-shaped array bracket to improve the overall stiffness of the W-shaped array bracket 2 and disperse the impact force. The bearing plate 3 has a thickness of 5 mm and a yield strength of 960 MPa. A bonding hole with a diameter of 140 mm is provided to ensure the connection strength between the concrete layer I 1 and the concrete layer II 4. The bearing plate 3 cooperates with the W-shaped array bracket 2. The b, c, and d bending parts of the W-shaped array bracket 2 are located outside the bonding hole. The impact force is transmitted to the bearing plate 3 through the W-shaped array bracket 2 to disperse the impact force. At the same time, the bearing plate 3 is made of high-strength steel, which improves the overall stiffness of the concrete protective structure and reduces the deformation. The composite reinforcement rib frame 5 is composed of a glass fiber rod 7 and a metal round tube 8. The glass fiber rod 7 has a diameter of 6 mm. The metal round tube 8 is made of Q235, has an outer diameter of 8 mm, and a wall thickness of 1 mm. The glass fiber rod 7 is placed in the metal round tube 8, and both ends are welded and sealed with metal discs. The metal discs have a diameter of 8 mm and a thickness of 1 mm. The composite reinforcement rib frame 5 is arranged in two layers, and the composite reinforcement ribs of each layer are crisscrossed with a spacing of 180 mm, and the intersections are spot welded. The two layers of the composite reinforcement ribs are connected by composite reinforcement ribs with a length of 75 mm, which are evenly arranged at each intersection and spot welded at the intersections. The composite reinforcement ribs have the strength of the glass fiber rod 7 and the toughness of the metal round tube 8, and are used to enhance the stiffness and toughness of the concrete layer II 4 and improve the protective capability of the concrete protective structure. The thickness of the polyurea coating 6 is 5mm. It is sprayed on the back of the concrete protective structure. The grade is NL-40, with a yield strength of 17.8MPa, a breaking strength of 36MPa, and an elongation of 340%. It can effectively prevent the splash of gravel caused by impact and avoid secondary damage to equipment and personnel inside the fortifications.

[0077] The concrete protective structure of the present invention is used in conjunction with a fortification skeleton. The fortification skeleton is "L"-shaped. Nuts can be embedded in the concrete protective structure and connected with the fortification skeleton by bolts to achieve modularization of the fortification. It can effectively resist strong impacts and secondary impacts of gravel, and is convenient for replacement and easy to repair after strong impact damage.

Claims

1. A composite multi-layer polyurea concrete protective structure resistant to strong impact, characterized in that: It comprises a concrete layer I (1), a load-bearing plate (3) made of high-strength steel, a concrete layer II (4) and a polyurea coating (6) which are arranged in sequence, wherein the concrete layer I (1) is the explosion-facing surface; A W-shaped array bracket (2) made of steel bars is cast in the concrete layer I (1), a plurality of bonding holes are arrayed on the load-bearing plate (3), and two inflection points at the bottom of each W-shaped unit of the W-shaped array bracket (2) are arranged outside the bonding holes of the load-bearing plate (3); a composite reinforcement rib frame (5) is cast in the concrete layer II (4), and the composite reinforcement ribs constituting the composite reinforcement rib frame (5) are composed of a metal round tube (8), a glass fiber rod (7) arranged in the metal round tube (8), and metal discs at both ends of the metal round tube (8); and the intersections of the composite reinforcement ribs are connected by spot welding.

2. The composite multi-layer polyurea concrete protective structure according to claim 1, characterized in that: The W-shaped array bracket (2) is composed of a plurality of groups of reinforcing ribs arranged in a crisscross pattern, each group of reinforcing ribs comprising a plurality of W-shaped units extending in one direction, the top two ends of each W-shaped unit being provided with extension parts extending outward, two adjacent W-shaped units being welded together via the extension parts, and the connection points of the extension parts being welded to the connection points of the extension parts of another group of reinforcing ribs arranged orthogonally, and the middle turning points of the W-shaped units being welded to the connecting steel bars arranged orthogonally.

3. The composite multi-layer polyurea concrete protective structure according to claim 2, characterized in that: The thickness of the concrete protective structure is H0, and the length and width are both L0. The thickness of the concrete layer I is H1, the height of the concrete layer II is H1, the height of the W-shaped array bracket (2), that is, the height of the W-shaped unit is h1, the bending height of the W-shaped unit is h2, the bending angle of the bending position of the W-shaped unit is 60°, the length of the W-shaped unit is 2b1, and the length of the W-shaped unit from the outermost end of the extension part on one side to the corresponding side inflection point at the bottom is b2; the size of the W-shaped unit satisfies the following formula: b2=tan 30°*h1 b1-b2=tan 30°*(h1-h2) The thickness H1 of concrete layer I satisfies the following formula: H1≥h1+20mm 4. The composite multi-layer polyurea concrete protective structure according to claim 3, characterized in that: The yield strength of the steel bars used in the W-shaped array bracket (2) is not less than 500 MPa, and the tensile strength is not less than 630 MPa.

5. The composite multi-layer polyurea concrete protective structure according to claim 4, characterized in that: The composite reinforcement rib frame (5) has two layers of composite reinforcement ribs, each layer is arranged in a crisscross pattern, and the two layers of composite reinforcement ribs are connected by composite reinforcement ribs and welded at the intersections; the height of the composite reinforcement rib frame (5) is f1, and the distribution width is f2, which meets the following requirements: f1=(H2-20) / 2 f2=(L0-40) / 9.

6. The composite multi-layer polyurea concrete protective structure according to claim 5, characterized in that: The diameter of the glass fiber rod (7) is equal to the inner diameter of the metal tube (8) and is not less than 6 mm; the glass fiber rod (7) is made of 60±10 fiber bundles twisted and woven, and the density of each fiber bundle is not less than 2.45 g / cm 3 , tensile strength is not less than 919MPa, Young's modulus is not less than 113MPa, and elongation is not less than 1.5%; the metal round tube (8) is made of Q235, with an outer diameter of 8mm-10mm and a wall thickness of not less than 1mm.

7. The composite multi-layer polyurea concrete protective structure according to claim 6, characterized in that: The material of the bearing plate (3) is Q960E, the yield strength is not less than 960 MPa, the thickness is not less than 5 mm, the diameter of the bonding hole of the bearing plate (3) is not less than 140 mm, the distance between the center of the edgemost bonding hole and the edge of the bearing plate is c1 and d1, the longitudinal and transverse hole spacings are c2 and d2, and meet the following requirements: c1=d1 c2=d2=(L0-2c1-r-40) / 8.

8. The composite multi-layer polyurea concrete protective structure according to claim 7, characterized in that: The polyurea coating is applied to the concrete surface using static mixing spraying equipment, with a thickness of not less than 5mm, a yield strength of not less than 17.8MPa, a breaking strength of not less than 36MPa, and an elongation of not less than 340%.

9. The composite multi-layer polyurea concrete protective structure according to claim 8, characterized in that: The concrete grade of the first layer of concrete used in the concrete layer I (1) and the concrete layer II (4) is not less than C40, the cement strength grade is not less than 42.5, and the coarse sand ratio is not less than 37%.

10. The composite multi-layer polyurea concrete protective structure according to claim 9, characterized in that: Nuts are embedded in the concrete protective structure and used to connect with the fortification frame bolts.

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