A damage-resistant, high-insulation, rapid-constructing composite material and a preparation method thereof

Abstract

This invention relates to a damage-resistant, highly insulating, and rapidly constructible composite material and its preparation method. The composite material comprises an outer layer, a middle layer, and an inner layer, sequentially compounded together. The outer layer is made of magnesium phosphate cement-based ultra-high performance concrete, the middle layer is made of magnesium phosphate cement-based foamed concrete, and the inner layer is made of magnesium phosphate cement-based high-strength concrete. Compared with existing technologies, the material of this invention exhibits excellent penetration resistance, blast resistance, and thermal insulation properties. Furthermore, the invented composite material features rapid setting and hardening, enabling efficient construction of components. In addition, the high bond strength between the outer, middle, and inner layers of the invented composite material avoids complex processes such as splicing and anchoring.

Description

Technical Field

[0001] This invention belongs to the field of building materials technology, and relates to a damage-resistant, high-insulation, and rapidly constructible composite material and its preparation method. Background Technology

[0002] In the modern military field, improving the penetration and blast resistance of concrete structures is crucial for ensuring troop safety and combat effectiveness. First, penetration resistance ensures that military facilities and equipment can withstand direct attacks from enemy weapons, thus protecting command centers, warehouses, and personnel. This characteristic not only enhances equipment survivability but also increases combat sustainability, ensuring the smooth conduct of operations. Second, blast resistance is particularly important when facing threats such as bombs and artillery shells. Efficient blast-resistant design can effectively reduce damage caused by blast shock waves, thereby lowering the risk of destruction to military targets. Furthermore, environmental conditions such as those at sea place high demands on the thermal conductivity of concrete structures. Effective thermal insulation not only protects equipment from normal operation in high-temperature environments but also provides a more comfortable living space for combat personnel. In particular, the ability to be rapidly constructed allows engineering structures to be deployed quickly in a short time, thereby improving reaction speed and mobility.

[0003] In summary, improved resistance to penetration, blast, and heat insulation, along with rapid construction capabilities, form the core elements of modern military engineering, providing a solid guarantee for achieving a superior position on the battlefield. However, existing concrete materials struggle to achieve the synergistic effect of these four properties.

[0004] Magnesium phosphate cement has the characteristics of early strength and rapid hardening. At present, research on magnesium phosphate cement mainly focuses on the repair of road surfaces and structures. For example, Chinese patent CN201911194878.2 discloses a slow-setting high-toughness magnesium phosphate cement road rapid repair material. However, its application in the fields of damage-resistant materials and rapid construction has not yet been seen. Summary of the Invention

[0005] The purpose of this invention is to provide a damage-resistant, highly insulating, and rapidly constructible composite material and its preparation method. This composite material comprises three layers: an outer layer of magnesium phosphate cement-based ultra-high performance concrete, possessing ultra-high strength and high toughness to ensure high penetration resistance; an inner layer of magnesium phosphate cement-based foamed concrete, ensuring high blast resistance and high thermal insulation; and a third inner layer of magnesium phosphate cement-based high-strength concrete, serving as the structural layer. Furthermore, the cementitious material is primarily magnesium phosphate cement, ensuring rapid construction of the composite material, thereby solving the problem of the difficulty in synergistically achieving penetration resistance, blast resistance, thermal insulation, and rapid construction in existing concrete materials.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] In one aspect, the present invention provides a damage-resistant, highly heat-insulating, and rapidly constructible composite material, comprising an outer layer material, a middle layer material, and an inner layer material sequentially compounded together. The outer layer material is made of magnesium phosphate cement-based ultra-high performance concrete, the middle layer material is made of magnesium phosphate cement-based foamed concrete, and the inner layer material is made of magnesium phosphate cement-based high-strength concrete.

[0008] The magnesium phosphate cement-based ultra-high performance concrete (outer layer material) comprises the following raw material components in parts by weight:

[0009] 500-1100 parts of calcined magnesium oxide, 400-900 parts of potassium dihydrogen phosphate, 9-25 parts of borax, 110-210 parts of fine sedimentary beads, 50-220 parts of steel fiber, 1000-2000 parts of river sand, and 180-250 parts of water.

[0010] The magnesium phosphate cement-based foamed concrete (intermediate layer material) comprises the following raw material components in parts by weight:

[0011] 500-1100 parts of calcined magnesium oxide, 400-900 parts of potassium dihydrogen phosphate, 5-50 parts of sodium carbonate, 5-50 parts of sodium bicarbonate, 0.5-3 parts of PE fiber, 100-650 parts of river sand, and 400-800 parts of water.

[0012] The magnesium phosphate cement-based high-strength concrete (inner layer material) comprises the following raw material components in parts by weight:

[0013] 500-1100 parts of calcined magnesium oxide, 400-900 parts of potassium dihydrogen phosphate, 15-45 parts of borax, 600-1200 parts of river sand, 600-1200 parts of crushed stone, and 300-500 parts of water.

[0014] Furthermore, in the raw material composition ratio of the above-mentioned layers, each component can independently select an extreme value or any intermediate value within the above-defined range. For example, for 500-1100 parts of reburned magnesium oxide, its weight parts can be selected as the two extreme values ​​of 500 parts and 1100 parts, or any intermediate value such as 600 parts, 700 parts, 800 parts, 900 parts, or 1000 parts. The same applies to the other components.

[0015] Furthermore, the recalcined magnesium oxide is obtained by melting and calcining magnesite powder at a high temperature above 1500℃.

[0016] Furthermore, the potassium dihydrogen phosphate is chemically analytical grade KH2PO4;

[0017] The borax is chemically analytical grade Na2B4O7·10H2O;

[0018] The sodium carbonate mentioned is chemically analytical grade Na2CO3;

[0019] The sodium bicarbonate mentioned is chemically analytical grade NaHCO3.

[0020] Furthermore, the particle size of the river sand is 0-5mm, and not equal to 0.

[0021] Furthermore, the crushed stone has a continuous gradation of 5-25mm.

[0022] Furthermore, the fine beads are solid spheres with a continuous particle size distribution, and the median particle size of the laser-coated beads is 5.5 mm.

[0023] Furthermore, the steel fiber is a micro-copper-plated steel fiber with a diameter of 0.15-0.25 mm, a length of 12-14 mm, an aspect ratio of 60-70, and a tensile strength of 2800-3200 MPa.

[0024] Furthermore, the PE fiber has a diameter of 11-13 μm, a length of 6-10 mm, an aspect ratio of 650-680, and a tensile strength of 2750-2850 MPa.

[0025] Furthermore, the outer layer material has a thickness of 60-200mm, the middle layer material has a thickness of 50-150mm, and the inner layer material has a thickness of 80-200mm.

[0026] In a second aspect, the present invention provides a method for preparing a damage-resistant, highly thermally insulating, and rapidly constructible composite material, comprising the following steps:

[0027] (1) Weigh the raw material components except water according to the proportion of magnesium phosphate cement-based high-strength concrete, add them to the mixer and mix them thoroughly to obtain a dry mixture. Then add water and mix to obtain a slurry, which is then poured into a mold to form the inner layer material.

[0028] (2) Continue to weigh the calcined magnesium oxide, potassium dihydrogen phosphate, PE fiber and river sand according to the proportion of magnesium phosphate cement-based foamed concrete and add them to the mixer. Mix them thoroughly to obtain a mixed dry material. Then add a mixture of sodium carbonate, sodium bicarbonate and water and mix it thoroughly to obtain a mixed slurry. Pour it directly onto the inner layer material to form the middle layer material.

[0029] (3) Finally, according to the proportion of magnesium phosphate cement-based ultra-high performance concrete, weigh the calcined magnesium oxide, potassium dihydrogen phosphate, borax, fine sedimentary beads, steel fiber and river sand and add them to the mixer. Mix them thoroughly to obtain a mixed dry material. Then add water to the mixed dry material and mix it evenly to obtain a mixed slurry. Pour it directly onto the intermediate layer material to form the outer layer material.

[0030] This composite material comprises three layers: the outer layer is magnesium phosphate cement-based ultra-high performance concrete, which improves the density of the matrix by using a low water-cement ratio and adding fine permeable beads. Furthermore, the addition of steel fibers enhances the toughness of the concrete, giving the outer layer ultra-high strength and high toughness, ensuring the composite material's high penetration resistance. The inner layer is magnesium phosphate cement-based foamed concrete, which introduces pores into the matrix by adding sodium carbonate and sodium bicarbonate, improving the energy absorption characteristics of the concrete and ensuring the composite material's high blast resistance and high thermal insulation performance. The final inner layer is magnesium phosphate cement-based high-strength concrete, serving as the structural layer. In addition, the cementitious material is primarily magnesium phosphate cement, ensuring rapid construction of the composite material. This combination of functional layers solves the problem of the difficulty in synergistically achieving penetration resistance, blast resistance, thermal insulation, and rapid construction in existing concrete materials. Detailed Implementation

[0031] The present invention will now be described in detail with reference to specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0032] The raw materials used in the following embodiments have the following requirements:

[0033] The calcined magnesium oxide was purchased from Qunli Mining Co., Ltd. in Haicheng City, Liaoning Province. It was obtained by melting and calcining magnesite powder at a high temperature above 1500℃, and the particle size was mainly distributed in 10-100μm.

[0034] Potassium dihydrogen phosphate is chemically analytical grade KH2PO4.

[0035] Borax is chemically analytical grade Na2B4O7·10H2O.

[0036] The particle size of the river sand is 0-5mm.

[0037] The crushed stone has a continuous gradation of 5-25mm.

[0038] The fine spherical particles are solid, with a continuous particle size distribution and are ultrafine. The median particle size of the laser-etched particles is 5.5 mm. The oxide composition is mainly SiO2, Al2O3 and CaO, etc., and they were purchased from Shenzhen Daote Technology Co., Ltd.

[0039] The steel fiber is a fine copper-plated steel fiber with a diameter of about 0.2 mm, a length of about 13 mm, an aspect ratio of about 65, and a tensile strength of about 3000 MPa.

[0040] The PE fiber has a diameter of approximately 12μm, a length of approximately 8mm, an aspect ratio of approximately 666, and a tensile strength of approximately 2790MPa.

[0041] Sodium carbonate is chemically analytical grade Na2CO3.

[0042] Sodium bicarbonate is chemically analytical grade NaHCO3.

[0043] The water used is tap water, which meets the requirements of the "Standard for Water Used in Concrete" (JGJ63-2006).

[0044] The mixer is a single-shaft mixer.

[0045] Unless otherwise specified, all other raw materials or processing techniques are commercially available materials or conventional processing techniques in the field.

[0046] Example 1

[0047] A damage-resistant, highly thermally insulating, and rapidly constructible composite material, comprising the following components by weight:

[0048] Inner layer material: 880 parts of calcined magnesium oxide, 750 parts of potassium dihydrogen phosphate, 30 parts of borax, 800 parts of river sand, 800 parts of crushed stone, and 360 parts of water.

[0049] Intermediate layer material: 880 parts of calcined magnesium oxide, 750 parts of potassium dihydrogen phosphate, 2 parts of PE fiber, 500 parts of river sand, 20 parts of sodium carbonate, 15 parts of sodium bicarbonate, and 600 parts of water.

[0050] Outer layer material: 880 parts of calcined magnesium oxide, 750 parts of potassium dihydrogen phosphate, 18 parts of borax, 163 parts of fine sedimentary beads, 150 parts of steel fiber, 1690 parts of river sand, and 215 parts of water.

[0051] Preparation method:

[0052] (1) The weighed calcined magnesium oxide, potassium dihydrogen phosphate, borax, river sand and crushed stone are added to the mixer in sequence and stirred for 3 minutes to obtain a mixed dry material. Then water is added to the mixed dry material and stirred for 2 minutes to obtain a mixed slurry. The slurry is poured into a mold with a size of φ500×240mm to form the inner layer of the composite material. The pouring thickness is 80mm, which is magnesium phosphate cement-based high-strength concrete.

[0053] (2) The weighed calcined magnesium oxide, potassium dihydrogen phosphate, PE fiber and river sand are added to the mixer in sequence and stirred for 3 minutes to obtain a mixed dry material. Then, a mixture of sodium carbonate, sodium bicarbonate and water is added to the mixed dry material and stirred for 1 minute to obtain a mixed slurry. This slurry is then poured directly onto the magnesium phosphate cement-based high-strength concrete to form the intermediate layer of the composite material. The pouring thickness is 80 mm, which is magnesium phosphate cement-based foamed concrete.

[0054] (3) The weighed calcined magnesium oxide, potassium dihydrogen phosphate, borax, fine sediment, steel fiber and river sand are added to the mixer in sequence and stirred for 3 minutes to obtain a mixed dry material. Then water is added to the mixed dry material and stirred for 2 minutes to obtain a mixed slurry. This slurry is then poured directly onto magnesium phosphate cement-based foamed concrete to form the outer layer of the composite material. The pouring thickness is 80 mm, which is magnesium phosphate cement-based ultra-high performance concrete.

[0055] (4) After the composite material has hardened, it can be demolded to obtain a damage-resistant, high-insulation, and rapid-construction material.

[0056] Example 2

[0057] A damage-resistant, highly thermally insulating, and rapidly constructible composite material, comprising the following components by weight:

[0058] Inner layer material: 660 parts of calcined magnesium oxide, 420 parts of potassium dihydrogen phosphate, 18 parts of borax, 600 parts of river sand, 800 parts of crushed stone, and 360 parts of water.

[0059] Intermediate layer material: 750 parts of calcined magnesium oxide, 660 parts of potassium dihydrogen phosphate, 2.3 parts of PE fiber, 400 parts of river sand, 18 parts of sodium carbonate, 18 parts of sodium bicarbonate, and 700 parts of water.

[0060] Outer layer material: 800 parts of calcined magnesium oxide, 700 parts of potassium dihydrogen phosphate, 20 parts of borax, 240 parts of fine sedimentary beads, 150 parts of steel fiber, 1690 parts of river sand, and 200 parts of water.

[0061] Preparation method:

[0062] (1) The weighed calcined magnesium oxide, potassium dihydrogen phosphate, borax, river sand and crushed stone are added to the mixer in sequence and stirred for 3 minutes to obtain a mixed dry material. Then water is added to the mixed dry material and stirred for 2 minutes to obtain a mixed slurry. The slurry is poured into a mold with a size of φ500×240mm to form the inner layer of the composite material. The pouring thickness is 80mm, which is magnesium phosphate cement-based high-strength concrete.

[0063] (2) The weighed calcined magnesium oxide, potassium dihydrogen phosphate, PE fiber and river sand are added to the mixer in sequence and stirred for 3 minutes to obtain a mixed dry material. Then, a mixture of sodium carbonate, sodium bicarbonate and water is added to the mixed dry material and stirred for 1 minute to obtain a mixed slurry. This slurry is then poured directly onto the magnesium phosphate cement-based high-strength concrete to form the intermediate layer of the composite material. The pouring thickness is 80 mm, which is magnesium phosphate cement-based foamed concrete.

[0064] (3) The weighed calcined magnesium oxide, potassium dihydrogen phosphate, borax, fine sediment, steel fiber and river sand are added to the mixer in sequence and stirred for 3 minutes to obtain a mixed dry material. Then water is added to the mixed dry material and stirred for 2 minutes to obtain a mixed slurry. This slurry is then poured directly onto magnesium phosphate cement-based foamed concrete to form the outer layer of the composite material. The pouring thickness is 80 mm, which is magnesium phosphate cement-based ultra-high performance concrete.

[0065] (4) After the composite material has hardened, it can be demolded to obtain a damage-resistant, high-insulation, and rapid-construction material.

[0066] Example 3

[0067] A damage-resistant, highly thermally insulating, and rapidly constructible composite material, comprising the following components by weight:

[0068] Inner layer material: 880 parts of calcined magnesium oxide, 750 parts of potassium dihydrogen phosphate, 30 parts of borax, 800 parts of river sand, 800 parts of crushed stone, and 360 parts of water.

[0069] Intermediate layer material: 880 parts of calcined magnesium oxide, 750 parts of potassium dihydrogen phosphate, 2 parts of PE fiber, 500 parts of river sand, 20 parts of sodium carbonate, 15 parts of sodium bicarbonate, and 600 parts of water.

[0070] Outer layer material: 880 parts of calcined magnesium oxide, 750 parts of potassium dihydrogen phosphate, 18 parts of borax, 163 parts of fine sedimentary beads, 150 parts of steel fiber, 1690 parts of river sand, and 215 parts of water.

[0071] Preparation method:

[0072] (1) The weighed calcined magnesium oxide, potassium dihydrogen phosphate, borax, river sand and crushed stone are added to the mixer in sequence and stirred for 3 minutes to obtain a mixed dry material. Then, water is added to the mixed dry material and stirred for 2 minutes to obtain a mixed slurry. The slurry is poured into a mold with a size of φ500×240mm to form the inner layer of the composite material. The pouring thickness is 100mm, which is magnesium phosphate cement-based high-strength concrete.

[0073] (2) The weighed calcined magnesium oxide, potassium dihydrogen phosphate, PE fiber and river sand are added to the mixer in sequence and stirred for 3 minutes to obtain a mixed dry material. Then, a mixture of sodium carbonate, sodium bicarbonate and water is added to the mixed dry material and stirred for 1 minute to obtain a mixed slurry. This slurry is then poured directly onto the magnesium phosphate cement-based high-strength concrete to form a composite material intermediate layer with a pouring thickness of 40 mm, which is magnesium phosphate cement-based foamed concrete.

[0074] (3) The weighed calcined magnesium oxide, potassium dihydrogen phosphate, borax, fine sediment, steel fiber and river sand are added to the mixer in sequence and stirred for 3 minutes to obtain a mixed dry material. Then water is added to the mixed dry material and stirred for 2 minutes to obtain a mixed slurry. This slurry is then poured directly onto magnesium phosphate cement-based foamed concrete to form the outer layer of the composite material. The pouring thickness is 100 mm, which is magnesium phosphate cement-based ultra-high performance concrete.

[0075] (4) After the composite material has hardened, it can be demolded to obtain a damage-resistant, high-insulation, and rapid-construction material.

[0076] Example 4

[0077] A damage-resistant, highly thermally insulating, and rapidly constructible composite material, comprising the following components by weight:

[0078] Inner layer material: 880 parts of calcined magnesium oxide, 750 parts of potassium dihydrogen phosphate, 30 parts of borax, 800 parts of river sand, 800 parts of crushed stone, and 360 parts of water.

[0079] Intermediate layer material: 880 parts of calcined magnesium oxide, 750 parts of potassium dihydrogen phosphate, 2 parts of PE fiber, 500 parts of river sand, 20 parts of sodium carbonate, 15 parts of sodium bicarbonate, and 600 parts of water.

[0080] Outer layer material: 880 parts of calcined magnesium oxide, 750 parts of potassium dihydrogen phosphate, 18 parts of borax, 163 parts of fine sedimentary beads, 150 parts of steel fiber, 1690 parts of river sand, and 215 parts of water.

[0081] Preparation method:

[0082] (1) The weighed calcined magnesium oxide, potassium dihydrogen phosphate, borax, river sand and crushed stone are added to the mixer in sequence and stirred for 3 minutes to obtain a mixed dry material. Then water is added to the mixed dry material and stirred for 2 minutes to obtain a mixed slurry. The slurry is poured into a mold with a size of φ500×240mm to form the inner layer of the composite material. The pouring thickness is 30mm, which is magnesium phosphate cement-based high-strength concrete.

[0083] (2) The weighed calcined magnesium oxide, potassium dihydrogen phosphate, PE fiber and river sand are added to the mixer in sequence and stirred for 3 minutes to obtain a mixed dry material. Then, a mixture of sodium carbonate, sodium bicarbonate and water is added to the mixed dry material and stirred for 1 minute to obtain a mixed slurry. This slurry is then poured directly onto the magnesium phosphate cement-based high-strength concrete to form a composite material intermediate layer with a pouring thickness of 40 mm, which is magnesium phosphate cement-based foamed concrete.

[0084] (3) The weighed calcined magnesium oxide, potassium dihydrogen phosphate, borax, fine sediment, steel fiber and river sand are added to the mixer in sequence and stirred for 3 minutes to obtain a mixed dry material. Then water is added to the mixed dry material and stirred for 2 minutes to obtain a mixed slurry. This slurry is then poured directly onto magnesium phosphate cement-based foamed concrete to form the outer layer of the composite material. The pouring thickness is 170 mm, which is magnesium phosphate cement-based ultra-high performance concrete.

[0085] (4) After the composite material has hardened, it can be demolded to obtain a damage-resistant, high-insulation, and rapid-construction material.

[0086] Example 5

[0087] A damage-resistant, highly thermally insulating, and rapidly constructible composite material, comprising the following components by weight:

[0088] Inner layer material: 880 parts of calcined magnesium oxide, 750 parts of potassium dihydrogen phosphate, 30 parts of borax, 800 parts of river sand, 800 parts of crushed stone, and 360 parts of water.

[0089] Intermediate layer material: 880 parts of calcined magnesium oxide, 750 parts of potassium dihydrogen phosphate, 2 parts of PE fiber, 500 parts of river sand, 20 parts of sodium carbonate, 15 parts of sodium bicarbonate, and 600 parts of water.

[0090] Outer layer material: 880 parts of calcined magnesium oxide, 750 parts of potassium dihydrogen phosphate, 18 parts of borax, 163 parts of fine sedimentary beads, 150 parts of steel fiber, 1690 parts of river sand, and 215 parts of water.

[0091] Preparation method:

[0092] (1) The weighed calcined magnesium oxide, potassium dihydrogen phosphate, borax, river sand and crushed stone are added to the mixer in sequence and stirred for 3 minutes to obtain a mixed dry material. Then water is added to the mixed dry material and stirred for 2 minutes to obtain a mixed slurry. The slurry is poured into a mold with a size of φ500×240mm to form the inner layer of the composite material. The pouring thickness is 80mm, which is magnesium phosphate cement-based high-strength concrete.

[0093] (2) The weighed calcined magnesium oxide, potassium dihydrogen phosphate, PE fiber and river sand are added to the mixer in sequence and stirred for 3 minutes to obtain a mixed dry material. Then, a mixture of sodium carbonate, sodium bicarbonate and water is added to the mixed dry material and stirred for 1 minute to obtain a mixed slurry. This slurry is then poured directly onto the magnesium phosphate cement-based high-strength concrete to form a composite material intermediate layer with a pouring thickness of 120 mm, which is magnesium phosphate cement-based foamed concrete.

[0094] (3) The weighed calcined magnesium oxide, potassium dihydrogen phosphate, borax, fine sediment, steel fiber and river sand are added to the mixer in sequence and stirred for 3 minutes to obtain a mixed dry material. Then water is added to the mixed dry material and stirred for 2 minutes to obtain a mixed slurry. This slurry is then poured directly onto magnesium phosphate cement-based foamed concrete to form the outer layer of the composite material. The pouring thickness is 40 mm, which is magnesium phosphate cement-based ultra-high performance concrete.

[0095] (4) After the composite material has hardened, it can be demolded to obtain a damage-resistant, high-insulation, and rapid-construction material.

[0096] Comparative Example 1:

[0097] The composite material was prepared using a common silicate cement system. The thicknesses of the outer, middle, and inner layers were the same as in Example 1. By weight, it included the following components:

[0098] Inner layer material: 100 parts of PII 52.5 grade ordinary Portland cement, 1000 parts of river sand, 800 parts of crushed stone, and 450 parts of water;

[0099] Intermediate layer materials: 1000 parts of PII 52.5 grade ordinary Portland cement, 2.5 parts of PE fiber, 1500 parts of river sand, 5 parts of composite foaming agent produced by Teshengqian New Building Materials Co., Ltd. (purchased from https: / / www.taobao.com / list / item / wap / 581873402493.htm), and 400 parts of water;

[0100] Outer layer material: 700 parts of PII·52.5 grade ordinary silicate cement, 300 parts of fine sedimentary beads, 100 parts of steel fiber, 1500 parts of river sand, 200 parts of water, and 20 parts of polycarboxylate superplasticizer.

[0101] Preparation method:

[0102] (1) Weigh out PII·52.5 grade ordinary silicate cement, river sand and crushed stone in sequence and add them to the mixer. Mix for 3 minutes to obtain a mixed dry material. Then add water to the mixed dry material and mix for 2 minutes to obtain a mixed slurry. Pour the slurry into a mold with a size of φ500×240mm to form the inner layer of the composite material with a pouring thickness of 80mm.

[0103] (2) Dilute the foaming agent with water and prepare the foam in advance. Add the weighed PII·52.5 grade ordinary silicate cement, PE fiber and river sand to the mixer in sequence and stir for 3 minutes to obtain the mixed dry material. Then add water to the mixed dry material and stir for 1 minute to obtain the mixed slurry. Add the pre-made foam to the mixed slurry and stir evenly. Pour it directly onto the inner concrete to form the intermediate layer of the composite material with a pouring thickness of 80 mm.

[0104] (3) The weighed PII·52.5 grade ordinary silicate cement, potassium dihydrogen phosphate, borax, fine sediment, steel fiber and river sand are added to the mixer in sequence and stirred for 3 minutes to obtain a mixed dry material. Then, water and polycarboxylate superplasticizer are added to the mixed dry material and stirred for 2 minutes to obtain a mixed slurry. This slurry is then poured directly onto the intermediate layer concrete to form the outer layer of the composite material with a pouring thickness of 80 mm.

[0105] (4) Once the composite material has hardened, it can be demolded.

[0106] Comparative Example 2

[0107] The high-strength concrete based on magnesium phosphate cement consists of the following components: 880 parts of reburned magnesium oxide, 750 parts of potassium dihydrogen phosphate, 30 parts of borax, 800 parts of river sand, 800 parts of crushed stone, and 360 parts of water.

[0108] Preparation method:

[0109] (1) The weighed calcined magnesium oxide, potassium dihydrogen phosphate, borax, river sand and gravel are added to the mixer in sequence and stirred for 3 minutes to obtain a mixed dry material. Then water is added to the mixed dry material and stirred for 2 minutes to obtain a mixed slurry. The slurry is poured into a mold with a size of φ500×240mm.

[0110] (2) Once the composite material has hardened, it can be demolded.

[0111] Comparative Example 3

[0112] The magnesium phosphate cement-based foamed concrete comprises the following components by weight: 880 parts of calcined magnesium oxide, 750 parts of potassium dihydrogen phosphate, 2 parts of PE fiber, 500 parts of river sand, 20 parts of sodium carbonate, 15 parts of sodium bicarbonate, and 600 parts of water.

[0113] Preparation method:

[0114] (1) The weighed calcined magnesium oxide, potassium dihydrogen phosphate, PE fiber and river sand are added to the mixer in sequence and stirred for 3 minutes to obtain a mixed dry material. Then, a mixture of sodium carbonate, sodium bicarbonate and water is added to the mixed dry material and stirred for 1 minute to obtain a mixed slurry. This slurry is then directly poured into a mold with a size of φ500×240mm.

[0115] (2) Once the composite material has hardened, it can be demolded.

[0116] Comparative Example 4

[0117] The ultra-high performance concrete based on magnesium phosphate cement comprises the following components by weight: 880 parts of reburned magnesium oxide, 750 parts of potassium dihydrogen phosphate, 18 parts of borax, 163 parts of fine sedimentary beads, 150 parts of steel fiber, 1690 parts of river sand, and 215 parts of water.

[0118] Preparation method:

[0119] (1) The weighed calcined magnesium oxide, potassium dihydrogen phosphate, borax, fine sediment, steel fiber and river sand are added to the mixer in sequence and stirred for 3 minutes to obtain a mixed dry material. Then water is added to the mixed dry material and stirred for 2 minutes to obtain a mixed slurry, which is then directly poured into a mold with a size of φ500×240mm.

[0120] (2) Once the composite material has hardened, it can be demolded.

[0121] Comparative Example 5

[0122] Inner layer material: 880 parts of calcined magnesium oxide, 750 parts of potassium dihydrogen phosphate, 30 parts of borax, 800 parts of river sand, 800 parts of crushed stone, and 360 parts of water.

[0123] Intermediate layer material: 880 parts of calcined magnesium oxide, 750 parts of potassium dihydrogen phosphate, 2 parts of PE fiber, 500 parts of river sand, 20 parts of sodium carbonate, 15 parts of sodium bicarbonate, and 600 parts of water.

[0124] Outer layer material: The composition is the same as that of the inner layer material.

[0125] Preparation method:

[0126] (1) The weighed calcined magnesium oxide, potassium dihydrogen phosphate, borax, river sand and gravel are added to the mixer in sequence and stirred for 3 minutes to obtain a mixed dry material. Then water is added to the mixed dry material and stirred for 2 minutes to obtain a mixed slurry. The slurry is poured into a mold with a size of φ500×240mm to form the inner layer of the composite material with a pouring thickness of 80mm.

[0127] (2) The weighed calcined magnesium oxide, potassium dihydrogen phosphate, PE fiber and river sand are added to the mixer in sequence and stirred for 3 minutes to obtain a mixed dry material. Then, a mixture of sodium carbonate, sodium bicarbonate and water is added to the mixed dry material and stirred for 1 minute to obtain a mixed slurry. This slurry is then poured directly onto the magnesium phosphate cement-based high-strength concrete to form the intermediate layer of the composite material with a pouring thickness of 80 mm.

[0128] (3) The weighed calcined magnesium oxide, potassium dihydrogen phosphate, borax, river sand and crushed stone are added to the mixer in sequence and stirred for 3 minutes to obtain a mixed dry material. Then water is added to the mixed dry material and stirred for 2 minutes to obtain a mixed slurry. This slurry is then poured directly onto magnesium phosphate cement-based foamed concrete to form the outer layer of the composite material with a pouring thickness of 80 mm.

[0129] (4) Once the composite material has hardened, it can be demolded.

[0130] Comparative Example 6

[0131] Outer layer material: 880 parts of calcined magnesium oxide, 750 parts of potassium dihydrogen phosphate, 30 parts of borax, 800 parts of river sand, 800 parts of crushed stone, and 360 parts of water;

[0132] Inner layer material: 880 parts of calcined magnesium oxide, 750 parts of potassium dihydrogen phosphate, 2 parts of PE fiber, 500 parts of river sand, 20 parts of sodium carbonate, 15 parts of sodium bicarbonate, and 600 parts of water.

[0133] Preparation method:

[0134] (1) The weighed calcined magnesium oxide, potassium dihydrogen phosphate, PE fiber and river sand are added to the mixer in sequence and stirred for 3 minutes to obtain a mixed dry material. Then, a mixture of sodium carbonate, sodium bicarbonate and water is added to the mixed dry material and stirred for 1 minute to obtain a mixed slurry. This slurry is then poured into a mold with a size of φ500×240mm to form the inner layer of the composite material with a pouring thickness of 120mm.

[0135] (2) The weighed calcined magnesium oxide, potassium dihydrogen phosphate, borax, river sand and gravel are added to the mixer in sequence and stirred for 3 minutes to obtain a mixed dry material. Then water is added to the mixed dry material and stirred for 2 minutes to obtain a mixed slurry. The slurry is poured onto the inner layer material to form the outer layer of the composite material with a pouring thickness of 120 mm.

[0136] (4) Once the composite material has hardened, it can be demolded.

[0137] Comparative Example 7

[0138] Inner layer material: 880 parts of calcined magnesium oxide, 750 parts of potassium dihydrogen phosphate, 30 parts of borax, 800 parts of river sand, 800 parts of crushed stone, and 360 parts of water.

[0139] Intermediate layer material: 880 parts of calcined magnesium oxide, 750 parts of potassium dihydrogen phosphate, 2 parts of PE fiber, 500 parts of river sand, 20 parts of sodium carbonate, 15 parts of sodium bicarbonate, and 600 parts of water.

[0140] Outer layer material: 880 parts of calcined magnesium oxide, 750 parts of potassium dihydrogen phosphate, 18 parts of borax, 1690 parts of river sand, and 215 parts of water.

[0141] Preparation method:

[0142] (1) The weighed calcined magnesium oxide, potassium dihydrogen phosphate, borax, river sand and gravel are added to the mixer in sequence and stirred for 3 minutes to obtain a mixed dry material. Then water is added to the mixed dry material and stirred for 2 minutes to obtain a mixed slurry. The slurry is poured into a mold with a size of φ500×240mm to form the inner layer of the composite material with a pouring thickness of 80mm.

[0143] (2) The weighed calcined magnesium oxide, potassium dihydrogen phosphate, PE fiber and river sand are added to the mixer in sequence and stirred for 3 minutes to obtain a mixed dry material. Then, a mixture of sodium carbonate, sodium bicarbonate and water is added to the mixed dry material and stirred for 1 minute to obtain a mixed slurry. This slurry is then poured directly onto the inner layer material to form the intermediate layer of the composite material with a pouring thickness of 80 mm.

[0144] (3) The weighed calcined magnesium oxide, potassium dihydrogen phosphate, borax and river sand are added to the mixer in sequence and stirred for 3 minutes to obtain a mixed dry material. Then water is added to the mixed dry material and stirred for 2 minutes to obtain a mixed slurry. This slurry is directly poured onto the intermediate layer material to form the outer layer of the composite material with a pouring thickness of 80 mm.

[0145] (4) Once the composite material has hardened, it can be demolded.

[0146] Performance testing:

[0147] Tests were conducted on the concrete used in Examples 1, 2, 3, 4, 5 and Comparative Examples 1, 2, 3, 4, 5, 6, 7. The method for determining the concrete setting time was referenced in GB / T 50080-2016, and the method for determining the thermal conductivity was referenced in GB / T10294-2008. Furthermore, penetration and blast resistance tests were performed on concrete targets. The penetration test used a scaled-down bunker buster with a DT300 high-strength alloy steel body, a diameter of 25 mm, an aspect ratio of 6, and a velocity of 200 m / s. The impact surface of the target was ensured to be perpendicular to the horizontal plane, with the center of the impact surface aligned with the muzzle center to guarantee vertical entry of the projectile into the target at the bullseye. For the blast resistance test, 1.0 kg TNT was used in a contact detonation mode, with the explosive placed directly in the center of the target surface. All explosive charges were effective. After the tests, the penetration depth and crater diameter were measured using a steel ruler. The results are shown in Table 1.

[0148] Table 1 Test Results

[0149]

[0150] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A damage-tolerant, high-thermal-insulation, rapid- construction composite material, characterized in that, It comprises an outer layer material, a middle layer material, and an inner layer material, which are sequentially composited. The outer layer material is made of magnesium phosphate cement-based ultra-high performance concrete, the middle layer material is made of magnesium phosphate cement-based foamed concrete, and the inner layer material is made of magnesium phosphate cement-based high-strength concrete. The magnesium phosphate cement-based ultra-high performance concrete comprises the following raw material components in parts by weight: 500-1100 parts of calcined magnesium oxide, 400-900 parts of potassium dihydrogen phosphate, 9-25 parts of borax, 110-210 parts of fine sedimentary beads, 50-220 parts of steel fiber, 1000-2000 parts of river sand, and 180-250 parts of water. The magnesium phosphate cement-based foamed concrete comprises the following raw material components in parts by weight: 500-1100 parts of calcined magnesium oxide, 400-900 parts of potassium dihydrogen phosphate, 5-50 parts of sodium carbonate, 5-50 parts of sodium bicarbonate, 0.5-3 parts of PE fiber, 100-650 parts of river sand, and 400-800 parts of water. The magnesium phosphate cement-based high-strength concrete comprises the following raw material components in parts by weight: 500-1100 parts of recalcined magnesium oxide, 400-900 parts of potassium dihydrogen phosphate, 15-45 parts of borax, 600-1200 parts of river sand, 600-1200 parts of crushed stone, and 300-500 parts of water. The particle size of the river sand is 0-5mm, and not equal to 0; The steel fiber is a fine copper-plated steel fiber with a diameter of 0.15~0.25 mm, a length of 12-14 mm, and a tensile strength of 2800~3200 MPa; The PE fiber has a diameter of 11~13 μm, a length of 6~10 mm, and a tensile strength of 2750~2850 MPa; The outer layer material has a thickness of 60-200 mm, the middle layer material has a thickness of 50-150 mm, and the inner layer material has a thickness of 80-200 mm. The recalcined magnesium oxide is obtained by melting and calcining magnesite powder at a high temperature above 1500 °C.

2. The damage-resistant, high-thermal-insulation, rapid- construction composite material according to claim 1, characterized in that, The potassium dihydrogen phosphate is chemically analytical grade KH2PO4; The borax is chemically analytical grade Na2B4O7·10H2O; The sodium carbonate mentioned is chemically analytical grade Na2CO3; The sodium bicarbonate mentioned is chemically analytical grade NaHCO3.

3. The method for preparing the damage-resistant, high-thermal-insulation, and rapidly constructible composite material as described in claim 1 or 2, characterized in that, Includes the following steps: (1) Weigh out the raw material components except water according to the proportion of magnesium phosphate cement-based high-strength concrete, add them to the mixer and mix them thoroughly to obtain a dry mixture. Then add water and mix to obtain a slurry, which is then poured into a mold to form the inner layer material. (2) Continue to weigh the calcined magnesium oxide, potassium dihydrogen phosphate, PE fiber and river sand according to the proportion of magnesium phosphate cement-based foamed concrete and add them to the mixer. Mix them thoroughly to obtain a mixed dry material. Then add a mixture of sodium carbonate, sodium bicarbonate and water and mix it thoroughly to obtain a mixed slurry. Pour it directly onto the inner layer material to form the middle layer material. (3) Finally, according to the proportion of magnesium phosphate cement-based ultra-high performance concrete, weigh the calcined magnesium oxide, potassium dihydrogen phosphate, borax, fine sedimentary beads, steel fiber and river sand and add them to the mixer. Mix them thoroughly to obtain a mixed dry material. Then add water to the mixed dry material and mix it evenly to obtain a mixed slurry. Pour it directly onto the intermediate layer material to form the outer layer material.

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