A high-strength antifreeze macroporous recycled concrete and its preparation method and application

Abstract

The present invention discloses a high-strength, frost-resistant, macroporous recycled concrete, and its preparation method and application. The raw materials of the macroporous concrete include the following components: 30-50 parts by weight of cement, 2-4.5 parts by weight of fly ash, 130-165 parts by weight of recycled concrete coarse aggregate, 10-16 parts by weight of antifreeze, 21-25 parts by weight of glass particles, 13-18 parts by weight of carbon black or iron black, 2-3.5 parts by weight of plastic fiber filaments, and 11-17 parts by weight of mixing water. The antifreeze is a particle formed by a solid phase change energy storage material core and an asphalt layer covering the surface thereof, and the asphalt layer is doped with a metal thermal conductor, rubber powder, and cement powder, and the phase change energy storage material is paraffin and / or sodium thiosulfate. The above-mentioned high-strength, frost-resistant, macroporous recycled concrete of the present invention effectively improves the strength and frost resistance of macroporous concrete prepared with recycled concrete aggregate, thereby increasing the service life of this type of solid waste macroporous concrete.

Description

Technical Field

[0001] The present invention relates to the technical field of macroporous concrete material preparation, and in particular to high-strength frost-resistant macroporous recycled concrete and a preparation method and application thereof. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to those skilled in the art.

[0003] With the advancement of urbanization in my country, the emission of construction solid waste (hereinafter referred to as construction solid waste) generated by construction, renovation, and demolition has increased year by year, reaching nearly 4 billion tons annually. However, the overall resource utilization rate is less than 10%. Huge amounts of construction solid waste are randomly piled up or simply landfilled, resulting in waste and shortage of land resources and causing serious environmental pollution. my country attaches great importance to the resource utilization of solid waste and actively promotes the concept of green, low-carbon and circular development. The resource utilization of construction solid waste is of great significance to the sustainable development of the construction industry and the protection and improvement of the ecological environment.

[0004] In recent years, research on the resource utilization of construction solid waste has become a hot topic. Relevant policies, standards, and systems in my country are gradually being improved. As construction solid waste resource utilization technology matures, it is crucial to recognize that applying construction solid waste to appropriate engineering fields is the right choice. Recycled concrete aggregate is currently one of the construction solid wastes. Maximizing the disposal of recycled concrete aggregate based on diversified recycled aggregate reinforcement technologies is an important approach to resource utilization of construction solid waste. Macroporous concrete, also known as permeable concrete, is a porous material with a skeleton-pore structure and a key support material for the "sponge city" construction concept. Using recycled concrete aggregate to prepare macroporous concrete is one approach to achieving large-scale resource utilization of construction solid waste. However, to maintain good permeability, macroporous concrete generally does not contain fine aggregate, resulting in weak connections between the recycled concrete aggregates. Furthermore, the inherent strength of recycled concrete aggregate is lower than that of natural aggregate, resulting in insufficient strength of this type of macroporous concrete. Furthermore, insufficient frost resistance of macroporous concrete can easily lead to freeze-thaw damage, directly affecting the service life of macroporous concrete. Summary of the Invention

[0005] The present invention provides high-strength, frost-resistant macroporous recycled concrete, its preparation method, and its application. This method effectively improves the strength and frost resistance of macroporous concrete made with recycled concrete aggregate, thereby extending the service life of this type of solid waste macroporous concrete. Specifically, the technical solution of the present invention is as follows.

[0006] First, the present invention discloses a high-strength, antifreeze, macroporous recycled concrete, the raw materials of which include the following components: 30-50 parts by weight of cement, 2-4.5 parts by weight of fly ash, 130-165 parts by weight of recycled concrete coarse aggregate, 10-16 parts by weight of antifreeze, 21-25 parts by weight of glass particles, 13-18 parts by weight of carbon black or iron black, 2-3.5 parts by weight of plastic fiber filaments, and 11-17 parts by weight of mixing water. The antifreeze is a particle formed by a solid phase-change energy storage material core and an asphalt layer covering the core, wherein the asphalt layer is doped with a metal thermal conductor, rubber powder, and cement powder, and the phase-change energy storage material is paraffin and / or sodium thiosulfate (Na2S2O3).

[0007] Furthermore, the preparation method of the antifreeze includes the following steps: granulating the phase change energy storage material into particles, and then spraying the coating liquid formed by emulsified asphalt and the metal thermal conductor, rubber powder and cement powder on the surface of the rolling particles for coating, and after completion, drying the obtained product.

[0008] Furthermore, the ratio of the emulsified asphalt, metal thermal conductor, rubber powder and cement powder is 100 parts by weight: 12-16 parts by weight: 20-28 parts by weight: 4-9 parts by weight. Preferably, the cement powder is the same as the cement in the above raw materials.

[0009] Furthermore, the ratio of the particles to the coating liquid is 1g:2.5-3.7ml.

[0010] Furthermore, the metal thermal conductor includes any one of aluminum powder, copper powder, etc. Optionally, the particle size of the metal thermal conductor is 400-600 mesh. The metal thermal conductor can effectively slow down the heat release rate of the antifreeze agent, thereby improving the antifreeze performance of the antifreeze agent.

[0011] Furthermore, the product is naturally dried at room temperature for 8 to 12 hours to dry the composite coating layer coated on the surface of the particles, and the particles are sealed in the coating layer to obtain the core-shell antifreeze.

[0012] Furthermore, the particle size of the recycled concrete coarse aggregate is 5 to 7 mm. Using the recycled concrete coarse aggregate as raw material not only promotes its resource utilization, but also utilizes the original alkaline slurry layer coated on the surface of the recycled concrete coarse aggregate as an alkali activator, promoting the hydration reaction of the cement, increasing the bonding strength between the recycled concrete coarse aggregate, and helping to improve the strength of the macroporous concrete of the present invention.

[0013] Furthermore, the particle size of the antifreeze agent is 0.4 to 1.0 mm. The antifreeze agent can fully utilize the phase change energy storage material to enhance the antifreeze ability of the macroporous concrete of the present invention.

[0014] Furthermore, the glass particles have a particle size of 20 to 50 mesh. Preferably, the glass particles are made from crushed waste glass. The addition of the glass particles helps increase the surface light transmittance of the prepared macroporous concrete, thereby promoting the absorption and conduction of solar heat by the carbon black or iron black in the macroporous concrete.

[0015] Furthermore, the plastic fiber filaments include at least one of polyvinyl alcohol fiber filaments, polypropylene fiber filaments, polyester fiber filaments, etc. Optionally, the plastic fiber filaments are 20 to 40 mm in length and 0.2 to 0.6 mm in diameter. The plastic fiber filaments are not only water-resistant and corrosion-resistant, but also effectively increase the crack resistance of macroporous concrete.

[0016] Furthermore, the invention further comprises 0.002 to 0.007 parts by weight of an air entraining agent. Optionally, the air entraining agent comprises any one of dodecyl sulfonate, alkylbenzene sulfonate, fatty alcohol polyoxyethylene ether, sodium fatty alcohol polyoxyethylene sulfonate, sodium fatty alcohol sulfate, methyl cellulose ether, and the like.

[0017] Furthermore, the invention further comprises 0.5 to 1.1 parts by weight of a water reducer. Optionally, the water reducer comprises any one of a polycarboxylate water reducer, a naphthalene water reducer, a lignin sulfonate water reducer, and the like.

[0018] Secondly, the present invention discloses a preparation method of the high-strength antifreeze macroporous recycled concrete, comprising the following steps: uniformly mixing the cement, fly ash, recycled concrete coarse aggregate, plastic fiber, glass particles, carbon black or iron black, and then adding the antifreeze agent and mixing water and mixing evenly to obtain the high-strength antifreeze macroporous recycled concrete.

[0019] Again, the present invention discloses the application of the high-strength antifreeze macroporous recycled concrete in the fields of construction engineering, road engineering, etc.

[0020] Compared with the prior art, the technical solution of the present invention has at least the following beneficial technical effects: the present invention uses recycled concrete aggregate as raw material to prepare macroporous concrete, which can promote the large-scale resource utilization of such bulk buildings and also contribute to the construction of "sponge cities". However, the mechanical strength and frost resistance of the macroporous concrete prepared from such construction solid waste are insufficient, which affects the life of the macroporous concrete. To this end, the present invention adds plastic fiber filaments to the macroporous concrete, which form an interwoven network structure in the macroporous concrete, which can effectively increase the crack resistance of the macroporous concrete and improve its mechanical strength. At the same time, the present invention utilizes the original alkaline slurry layer wrapped on the surface of the recycled concrete coarse aggregate as an alkali activator, which helps to promote the hydration reaction of the cement, thereby increasing the bonding force between the recycled concrete coarse aggregate and improving the strength of the macroporous concrete. In addition, the present invention also provides a core-shell antifreeze agent, and adds glass particles and carbon black or iron black, which work together to effectively improve the frost resistance of the macroporous concrete of the present invention. The reason is: first, the antifreeze of the present invention is a particle formed by a solid phase change energy storage material core and an asphalt layer covering its surface, and the asphalt layer is doped with metal thermal conductor and rubber powder. The composite coating layer formed by the asphalt layer and the metal thermal conductor, rubber powder and cement powder provides a stable place for solid-liquid conversion for the phase change energy storage material core, thereby avoiding the loss and consumption of the phase change energy storage material and allowing the antifreeze to play its role repeatedly. The asphalt layer and rubber powder have relatively poor thermal conductivity, which allows them to better lock in the heat stored in the phase-change energy storage material. The metal thermal conductors dispersed within the composite coating act as heat transfer sites, enabling both internal and external heat exchange and controlling the release of heat from the phase-change energy storage material. This is due to the poor thermal conductivity of the asphalt layer and rubber powder, which allows heat to be preferentially released outward from these heat transfer sites. Furthermore, the macroporous concrete of the present invention, based on a matrix of low-thermal-conductivity cement, fly ash, and recycled concrete coarse aggregate, encapsulates the antifreeze agent, allowing the heat in the antifreeze agent to be gradually released primarily through these heat transfer sites. This effectively increases the duration of the antifreeze agent's effectiveness and enhances its antifreeze effectiveness. Furthermore, the asphalt layer and the rubber powder dispersed therein impart a certain degree of deformation to the antifreeze agent, absorbing the pressure caused by the volume expansion of frozen water within the pores of the macroporous concrete, thereby improving the concrete's crack resistance and the antifreeze agent's adaptability. The cement powder dispersed in the asphalt layer can undergo a hydration reaction with the cement in the raw materials under the action of mixing water to form a gelling component, so that the antifreeze of the present invention participates in the reaction of the macroporous concrete matrix and is organically integrated into one, preventing the antifreeze particles from being separated from the matrix due to volume changes caused by freezing and thawing during the service of the macroporous concrete, thereby preventing the blockage of water-permeable pores.Furthermore, the glass particles added to the present invention not only promote the resource utilization of waste glass, but also help increase the surface light transmittance of the macroporous concrete during the day, increasing the heat-receiving area of the macroporous concrete. This allows sunlight to penetrate deeper into the surface layer of the macroporous concrete and come into contact with more of the carbon black or iron black. The carbon black or iron black distributed on the surface and in the surface layer of the macroporous concrete efficiently absorbs solar energy and converts it into heat, which is then transferred to the phase change energy storage material in the antifreeze agent for storage. This heat is then released when the ambient temperature drops, thereby improving the antifreeze ability of the macroporous concrete. Furthermore, the carbon black or iron black dispersed in the macroporous concrete of the present invention also helps improve its crack resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute undue limitations thereon. The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0022] Figure 1 This is a rendering of the macroporous concrete mixture prepared in the following Example 1.

[0023] Figure 2 This is a diagram showing the effect of the compressive strength test of the macroporous concrete prepared in Example 1 below. DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are intended to illustrate the present invention only and are not intended to limit the scope of the invention. The experimental methods in the following examples, for which specific conditions are not specified, are generally performed under conventional conditions or as recommended by the manufacturer.

[0025] Unless otherwise defined, all professional and scientific terms used in the present invention have the same meaning as those familiar to those skilled in the art. The reagents or raw materials used in the present invention can be purchased through conventional channels. Unless otherwise specified, the reagents or raw materials used in the present invention are used in a conventional manner in the art or according to the product instructions. In addition, any method and material similar to or equivalent to the described content can be applied to the inventive method. The preferred embodiments and materials described in the present invention are for demonstration purposes only.

[0026] Example 1

[0027] A method for preparing high-strength frost-resistant macroporous recycled concrete comprises the following steps:

[0028] (1) Preparation of antifreeze: The phase change energy storage material (paraffin powder) is granulated into paraffin particles in a granulator and set aside. Then, emulsified asphalt with a solid content of 20% (model PC-3, Guangzhou Naika Waterproof Building Materials Co., Ltd., other embodiments use the same emulsified asphalt), 500-mesh aluminum powder, 100-mesh rubber powder, and 42.5 ordinary Portland cement powder are mixed in a ratio of 100 parts by weight: 14 parts by weight: 25 parts by weight: 7 parts by weight, and stirred evenly to form a coating liquid. Then, the coating liquid is gradually sprayed on the surface of the rolling paraffin particles in a material-liquid ratio of 1 g: 3.2 ml to coat the surface. After completion, the obtained product is naturally dried at room temperature for 10 hours to obtain antifreeze particles. Then, particles with a particle size between 0.4 and 0.7 mm are screened out and set aside.

[0029] (2) Prepare the following raw materials: 42 parts by weight of 42.5% ordinary Portland cement, 3.8 parts by weight of fly ash, 155 parts by weight of recycled concrete coarse aggregate, 14 parts by weight of the antifreeze prepared in this example, 23 parts by weight of glass particles, 16 parts by weight of N115 carbon black, 3 parts by weight of polypropylene fiber, and 15 parts by weight of mixing water. The particle size of the recycled concrete coarse aggregate is between 5 and 7 mm. The particle size distribution of the glass particles is between 20 and 30 mesh. The length of the polypropylene fiber is 30 to 40 mm, and the diameter is 0.4 to 0.6 mm.

[0030] (3) The cement, fly ash, recycled concrete coarse aggregate, polypropylene fiber, glass particles, and carbon black prepared in step (2) are placed in a mixer and mixed for 10 minutes. Then, the antifreeze particles and mixing water are added and stirred for 5 minutes to obtain a macroporous concrete mixture. Figure 1 shown.

[0031] 1. The macroporous concrete mixture prepared in this embodiment is made into a macroporous concrete test block, and then the 28d compressive strength of the macroporous concrete is tested according to GB / T50081-2002 "Standard for Test Methods of Mechanical Properties of Ordinary Concrete" (such as Figure 2 The test results are shown in the following table.

[0032] 2. The macroporous concrete mixture prepared in this embodiment was made into a macroporous concrete test block, and then the frost resistance test of the macroporous concrete test block was carried out according to GB / T4111-2013 "Test Methods for Concrete Blocks and Bricks" (the number of freeze-thaw cycles was 20 times), and the average compressive strength loss rate of the macroporous concrete test block before and after freeze-thaw treatment was calculated (the smaller the loss rate, the better the frost resistance). The test results are shown in the following table.

[0033] 3. The macroporous concrete test block after the frost resistance test was used as the test object. The water permeability coefficient of the object at a water temperature of 15°C was tested according to GB / T25993-2010 "Permeable Pavement Bricks and Permeable Road Slabs" (the larger the water permeability coefficient, the better the water permeability). The test results are shown in the following table.

[0034] Example No. 28d compressive strength Average compressive strength loss rate Permeability coefficient 1 57.32MPa 0.48％ 13.7mm / s

[0035] Example 2

[0036] A method for preparing high-strength frost-resistant macroporous recycled concrete comprises the following steps:

[0037] (1) Preparation of antifreeze: Phase change energy storage material (Na2S2O3 powder) is granulated into sodium thiosulfate particles in a granulator for later use. Then, emulsified asphalt with a solid content of 20%, 600-mesh copper powder, 80-mesh rubber powder, and 42.5-weight ordinary Portland cement powder are mixed in a ratio of 100 parts by weight: 12 parts by weight: 28 parts by weight: 9 parts by weight, and stirred evenly to form a coating liquid. Then, the coating liquid is gradually sprayed onto the surface of the rolling sodium thiosulfate particles in a material-liquid ratio of 1 g: 3.7 ml to coat the liquid. After completion, the obtained product is naturally dried at room temperature for 12 hours to obtain antifreeze particles. Then, particles with a particle size between 0.5 and 0.8 mm are screened out for later use.

[0038] (2) Prepare the following raw materials: 30 parts by weight of 42.5 ordinary Portland cement, 2 parts by weight of fly ash, 130 parts by weight of recycled concrete coarse aggregate, 10 parts by weight of the antifreeze prepared in this example, 25 parts by weight of glass particles, 13 parts by weight of N110 carbon black, 2 parts by weight of polyvinyl alcohol fiber, and 11 parts by weight of mixing water. The particle size of the recycled concrete coarse aggregate is between 5 and 7 mm. The particle size distribution of the glass particles is between 40 and 50 mesh. The length of the polyvinyl alcohol fiber is 20 to 30 mm, and the diameter is 0.2 to 0.5 mm.

[0039] (3) The cement, fly ash, recycled concrete coarse aggregate, polyvinyl alcohol fiber, glass particles, and carbon black prepared in step (2) are placed in a mixer and mixed for 10 minutes, and then the antifreeze particles and mixing water are added and stirred for 5 minutes to obtain a macroporous concrete mixture.

[0040] The same method as in Example 1 was used to test the 28d compressive strength, average compressive strength loss rate, and water permeability coefficient of the macroporous concrete test blocks prepared from the macroporous concrete mixture described in this example. The results are shown in the following table.

[0041] Example No. 28d compressive strength Average compressive strength loss rate Permeability coefficient 2 55.18MPa 0.52％ 13.4mm / s

[0042] Example 3

[0043] A method for preparing high-strength frost-resistant macroporous recycled concrete comprises the following steps:

[0044] (1) Preparation of antifreeze: Phase change energy storage material (Na2S2O3 powder) is granulated into sodium thiosulfate particles in a granulator for later use. Then, emulsified asphalt with a solid content of 23%, 550-mesh copper powder, 100-mesh rubber powder, and 42.5-weight ordinary Portland cement powder are mixed in a ratio of 100 parts by weight: 15 parts by weight: 23 parts by weight: 6 parts by weight, and stirred evenly to form a coating liquid. Then, the coating liquid is gradually sprayed onto the surface of the rolling sodium thiosulfate particles in a material-liquid ratio of 1 g: 3 ml to coat the liquid. After completion, the obtained product is naturally dried at room temperature for 10 hours to obtain antifreeze particles. Then, particles with a particle size between 0.7 and 1.0 mm are screened out for later use.

[0045] (2) Prepare the following raw materials in the following proportions: 50 parts by weight of 42.5 ordinary Portland cement, 4.5 parts by weight of fly ash, 165 parts by weight of recycled concrete coarse aggregate, 16 parts by weight of the antifreeze prepared in this example, 21 parts by weight of glass particles, 18 parts by weight of iron black, 3.5 parts by weight of polyvinyl alcohol fiber, 0.007 parts by weight of sodium lauryl sulfate, 1.1 parts by weight of polycarboxylic acid water reducer, and 17 parts by weight of mixing water. The particle size of the recycled concrete coarse aggregate is between 5 and 7 mm. The particle size distribution of the glass particles is between 30 and 50 mesh. The length of the polyvinyl alcohol fiber is 30 to 40 mm, and the diameter is 0.2 to 0.4 mm. The particle size of the iron black is mainly distributed between 200 and 300 mesh. The water reduction rate of the polycarboxylic acid water reducer is 20%.

[0046] (3) The cement, fly ash, recycled concrete coarse aggregate, polyvinyl alcohol fiber, glass particles, iron black, and sodium dodecyl sulfate prepared in step (2) are placed in a mixer and mixed for 10 minutes. Then, the antifreeze particles, polycarboxylate water reducer, and mixing water are added and stirred for 5 minutes to obtain a macroporous concrete mixture.

[0047] The same method as in Example 1 was used to test the 28d compressive strength, average compressive strength loss rate, and water permeability coefficient of the macroporous concrete test blocks prepared from the macroporous concrete mixture described in this example. The results are shown in the following table.

[0048] Example No. 28d compressive strength Average compressive strength loss rate Permeability coefficient 3 58.75MPa 0.41％ 14.2mm / s

[0049] Example 4

[0050] A method for preparing high-strength frost-resistant macroporous recycled concrete comprises the following steps:

[0051] (1) Preparation of antifreeze: The phase change energy storage material (paraffin powder) is granulated into paraffin particles in a granulator and set aside. Then, emulsified asphalt with a solid content of 20%, 400-mesh aluminum powder, 100-mesh rubber powder, and 42.5-weight ordinary Portland cement powder are mixed in a ratio of 100 parts by weight: 16 parts by weight: 20 parts by weight: 4 parts by weight and stirred evenly to form a coating liquid. Then, the coating liquid is gradually sprayed on the surface of the rolling paraffin particles in a material-liquid ratio of 1 g: 2.5 ml to coat the liquid. After completion, the obtained product is naturally dried at room temperature for 8 hours to obtain antifreeze particles. Then, particles with a particle size between 0.5 and 0.7 mm are screened out and set aside.

[0052] (2) Prepare the following raw materials in the following proportions: 45 parts by weight of 42.5 ordinary Portland cement, 4.1 parts by weight of fly ash, 160 parts by weight of recycled concrete coarse aggregate, 14.5 parts by weight of the antifreeze agent prepared in this example, 24 parts by weight of glass particles, 17 parts by weight of iron black, 3.2 parts by weight of polypropylene fiber, 0.002 parts by weight of sodium alkylbenzene sulfonate, 0.5 parts by weight of polycarboxylic acid water reducer, and 15.5 parts by weight of mixing water. The particle size of the recycled concrete coarse aggregate is between 5 and 7 mm. The particle size distribution of the glass particles is between 30 and 50 mesh. The length of the polypropylene fiber is 30 to 40 mm, and the diameter is 0.2 to 0.4 mm. The particle size of the iron black is mainly distributed between 200 and 300 mesh. The water reduction rate of the polycarboxylic acid water reducer is 20%.

[0053] (3) The cement, fly ash, recycled concrete coarse aggregate, polypropylene fiber, glass particles, iron black, and sodium alkylbenzene sulfonate prepared in step (2) are placed in a mixer and mixed for 10 minutes. Then, the antifreeze particles, polycarboxylate water reducer, and mixing water are added and stirred for 5 minutes to obtain a macroporous concrete mixture.

[0054] The same method as in Example 1 was used to test the 28d compressive strength, average compressive strength loss rate, and water permeability coefficient of the macroporous concrete test blocks prepared from the macroporous concrete mixture described in this example. The results are shown in the following table.

[0055] Example No. 28d compressive strength Average compressive strength loss rate Permeability coefficient 4 58.46MPa 0.38％ 14.4mm / s

[0056] Example 5

[0057] A method for preparing high-strength frost-resistant macroporous recycled concrete comprises the following steps:

[0058] (1) Prepare the following raw materials: 42 parts by weight of 42.5% ordinary Portland cement, 3.8 parts by weight of fly ash, 155 parts by weight of recycled concrete coarse aggregate, 14 parts by weight of antifreeze prepared according to the method of Example 1, 23 parts by weight of glass particles, 16 parts by weight of N115 carbon black, and 15 parts by weight of mixing water. The recycled concrete coarse aggregate has a particle size between 5 and 7 mm. The glass particles have a particle size distribution between 20 and 30 mesh.

[0059] (2) The cement, fly ash, recycled concrete coarse aggregate, glass particles, and carbon black prepared in step (1) are placed in a mixer and mixed for 10 minutes, and then the antifreeze particles and mixing water are added and stirred for 5 minutes to obtain a macroporous concrete mixture.

[0060] The same method as in Example 1 was used to test the 28d compressive strength, average compressive strength loss rate, and water permeability coefficient of the macroporous concrete test blocks prepared from the macroporous concrete mixture described in this example. The results are shown in the following table.

[0061] Example No. 28d compressive strength Average compressive strength loss rate Permeability coefficient 5 51.04MPa 1.79％ 10.3mm / s

[0062] Example 6

[0063] A method for preparing high-strength frost-resistant macroporous recycled concrete comprises the following steps:

[0064] (1) Prepare the following raw materials in the following proportions: 42 parts by weight of 42.5 ordinary Portland cement, 3.8 parts by weight of fly ash, 155 parts by weight of recycled concrete coarse aggregate, 23 parts by weight of glass particles, 16 parts by weight of N115 carbon black, 3 parts by weight of polypropylene fiber, and 15 parts by weight of mixing water. The particle size of the recycled concrete coarse aggregate is between 5 and 7 mm. The particle size distribution of the glass particles is between 20 and 30 mesh. The length of the polypropylene fiber is 30 to 40 mm, and the diameter is 0.4 to 0.6 mm.

[0065] (2) The cement, fly ash, recycled concrete coarse aggregate, polypropylene fiber, glass particles, and carbon black prepared in step (1) are placed in a mixer and mixed for 10 minutes, and then the mixing water is added and stirred for 5 minutes to obtain a macroporous concrete mixture.

[0066] The same method as in Example 1 was used to test the 28d compressive strength, average compressive strength loss rate, and water permeability coefficient of the macroporous concrete test blocks prepared from the macroporous concrete mixture described in this example. The results are shown in the following table.

[0067] Example No. 28d compressive strength Average compressive strength loss rate Permeability coefficient 6 57.11MPa 1.54％ 12.5mm / s

[0068] Example 7

[0069] A method for preparing high-strength frost-resistant macroporous recycled concrete comprises the following steps:

[0070] (1) Prepare the following raw materials: 30 parts by weight of 42.5 ordinary Portland cement, 2 parts by weight of fly ash, 130 parts by weight of recycled concrete coarse aggregate, 10 parts by weight of antifreeze prepared according to the method of Example 2, 13 parts by weight of N110 carbon black, 2 parts by weight of polyvinyl alcohol fiber, and 11 parts by weight of mixing water. The particle size of the recycled concrete coarse aggregate is between 5 and 7 mm. The particle size distribution of the glass particles is between 40 and 50 mesh. The length of the polyvinyl alcohol fiber is 20 to 30 mm, and the diameter is 0.2 to 0.5 mm.

[0071] (2) The cement, fly ash, recycled concrete coarse aggregate, polyvinyl alcohol fiber and carbon black prepared in step (1) are placed in a mixer and mixed for 10 minutes, and then the antifreeze particles and mixing water are added and stirred for 5 minutes to obtain a macroporous concrete mixture.

[0072] The same method as in Example 1 was used to test the 28d compressive strength, average compressive strength loss rate, and water permeability coefficient of the macroporous concrete test blocks prepared from the macroporous concrete mixture described in this example. The results are shown in the following table.

[0073] Example No. 28d compressive strength Average compressive strength loss rate Permeability coefficient 7 56.07MPa 0.92％ 12.8mm / s

[0074] Example 8

[0075] A method for preparing high-strength frost-resistant macroporous recycled concrete comprises the following steps:

[0076] (2) Prepare the following raw materials: 30 parts by weight of 42.5% ordinary Portland cement, 2 parts by weight of fly ash, 130 parts by weight of recycled concrete coarse aggregate, 10 parts by weight of antifreeze prepared according to the method of Example 2, 25 parts by weight of glass particles, 2 parts by weight of polyvinyl alcohol fiber, and 11 parts by weight of mixing water. The recycled concrete coarse aggregate has a particle size of 5 to 7 mm. The glass particles have a particle size distribution of 40 to 50 mesh. The polyvinyl alcohol fiber has a length of 20 to 30 mm and a diameter of 0.2 to 0.5 mm.

[0077] (3) The cement, fly ash, recycled concrete coarse aggregate, polyvinyl alcohol fiber, and glass particles prepared in step (2) are placed in a mixer and mixed for 10 minutes, and then the antifreeze particles and mixing water are added and stirred for 5 minutes to obtain a macroporous concrete mixture.

[0078] The same method as in Example 1 was used to test the 28d compressive strength, average compressive strength loss rate, and water permeability coefficient of the macroporous concrete test blocks prepared from the macroporous concrete mixture described in this example. The results are shown in the following table.

[0079] Example No. 28d compressive strength Average compressive strength loss rate Permeability coefficient 8 52.26MPa 1.39％ 12.2mm / s

[0080] Example 9

[0081] A method for preparing high-strength frost-resistant macroporous recycled concrete comprises the following steps:

[0082] (1) Prepare the following raw materials in the following proportions: 50 parts by weight of 42.5 ordinary Portland cement, 4.5 parts by weight of fly ash, 165 parts by weight of recycled concrete coarse aggregate, 16 parts by weight of antifreeze (sodium thiosulfate particles), 21 parts by weight of glass particles, 18 parts by weight of iron black, 3.5 parts by weight of polyvinyl alcohol fiber, 0.007 parts by weight of sodium lauryl sulfate, 1.1 parts by weight of polycarboxylic acid water reducer, and 17 parts by weight of mixing water. The particle size of the recycled concrete coarse aggregate is between 5 and 7 mm. The particle size distribution of the glass particles is between 30 and 50 mesh. The length of the polyvinyl alcohol fiber is 30 to 40 mm, and the diameter is 0.2 to 0.4 mm. The particle size of the iron black is mainly distributed between 200 and 300 mesh. The water reduction rate of the polycarboxylic acid water reducer is 20%.

[0083] (2) The cement, fly ash, recycled concrete coarse aggregate, polyvinyl alcohol fiber, glass particles, iron black, and sodium dodecyl sulfate prepared in step (1) are placed in a mixer and mixed for 10 minutes, and then the antifreeze agent, polycarboxylate water reducer, and mixing water are added and stirred for 5 minutes to obtain a macroporous concrete mixture.

[0084] The same method as in Example 1 was used to test the 28d compressive strength, average compressive strength loss rate, and water permeability coefficient of the macroporous concrete test blocks prepared from the macroporous concrete mixture described in this example. The results are shown in the following table.

[0085] Example No. 28d compressive strength Average compressive strength loss rate Permeability coefficient 9 54.43MPa 1.28％ 14.4mm / s

[0086] Example 10

[0087] A method for preparing high-strength, antifreeze, macroporous recycled concrete is similar to that of Example 3, except that the antifreeze agent of this embodiment is prepared as follows: a phase change energy storage material (Na2S2O3 powder) is granulated into sodium thiosulfate granules in a granulator and set aside. Emulsified asphalt with a solid content of 23%, 100-mesh rubber powder, and 42.5% ordinary Portland cement powder are then mixed in a ratio of 100 parts by weight: 23 parts by weight: 6 parts by weight and stirred uniformly to form a coating liquid. The coating liquid is then gradually sprayed onto the surface of the rolling sodium thiosulfate granules at a material-liquid ratio of 1 g: 3 ml to coat the granules. The resulting product is then air-dried at room temperature for 10 hours to obtain antifreeze granules. Particles with a particle size between 0.7 and 1.0 mm are then screened to obtain the antifreeze granules.

[0088] The same method as in Example 1 was used to test the 28d compressive strength, average compressive strength loss rate, and water permeability coefficient of the macroporous concrete test blocks prepared from the macroporous concrete mixture described in this example. The results are shown in the following table.

[0089] Example No. 28d compressive strength Average compressive strength loss rate Permeability coefficient 10 58.12MPa 0.84％ 13.9mm / s

[0090] Example 11

[0091] A method for preparing high-strength, antifreeze-resistant, macroporous recycled concrete is similar to the above-mentioned Example 4, except that the antifreeze agent of this embodiment is prepared as follows: a phase-change energy storage material (paraffin powder) is granulated into paraffin wax particles in a granulator and set aside. Then, emulsified asphalt with a solid content of 20%, 400-mesh aluminum powder, and 100-mesh rubber powder are mixed in a ratio of 100 parts by weight: 16 parts by weight: 20 parts by weight and stirred evenly to form a coating liquid. The coating liquid is then gradually sprayed onto the surface of the rolling paraffin wax particles at a material-liquid ratio of 1 g: 2.5 ml to coat the particles. After completion, the resulting product is naturally dried at room temperature for 8 hours to obtain antifreeze particles. Particles with a particle size between 0.5 and 0.7 mm are then screened to obtain the antifreeze particles.

[0092] The same method as in Example 1 was used to test the 28d compressive strength, average compressive strength loss rate, and water permeability coefficient of the macroporous concrete test blocks prepared from the macroporous concrete mixture described in this example. The results are shown in the following table.

[0093] Example No. 28d compressive strength Average compressive strength loss rate Permeability coefficient 11 57.33MPa 0.51％ 11.7mm / s

[0094] Example 12

[0095] A method for preparing high-strength, antifreeze-resistant, macroporous recycled concrete is similar to the above-mentioned Example 4, except that the antifreeze agent of this embodiment is prepared as follows: a phase change energy storage material (paraffin powder) is granulated into paraffin wax particles in a granulator and set aside. Then, emulsified asphalt with a solid content of 20%, 400-mesh aluminum powder, and 42.5% ordinary Portland cement powder are mixed in a ratio of 100 parts by weight: 16 parts by weight: 4 parts by weight and stirred evenly to form a coating liquid. The coating liquid is then gradually sprayed onto the surface of the rolling paraffin wax particles at a material-liquid ratio of 1 g: 2.5 ml to coat the particles. After completion, the resulting product is naturally dried at room temperature for 8 hours to obtain antifreeze particles. Particles with a particle size between 0.5 and 0.7 mm are then screened and set aside.

[0096] The same method as in Example 1 was used to test the 28d compressive strength, average compressive strength loss rate, and water permeability coefficient of the macroporous concrete test blocks prepared from the macroporous concrete mixture described in this example. The results are shown in the following table.

[0097] Example No. 28d compressive strength Average compressive strength loss rate Permeability coefficient 12 57.81MPa 0.73％ 13.1mm / s

[0098] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A high-strength antifreeze macroporous recycled concrete, characterized in that: The raw materials of the macroporous recycled concrete include the following components: 30-50 parts by weight of cement, 2-4.5 parts by weight of fly ash, 130-165 parts by weight of recycled concrete coarse aggregate, 10-16 parts by weight of antifreeze, 21-25 parts by weight of glass particles, 13-18 parts by weight of carbon black or iron black, 2-3.5 parts by weight of plastic fiber filaments, and 11-17 parts by weight of mixing water; The antifreeze is a particle formed by a solid phase-change energy storage material core and an asphalt layer covering the surface thereof, and the asphalt layer is doped with a metal thermal conductor, rubber powder and cement powder, and the phase-change energy storage material is paraffin and / or sodium thiosulfate; the preparation of the antifreeze comprises the steps of: granulating the phase-change energy storage material into particles, and then spraying a coating liquid formed by emulsified asphalt and the metal thermal conductor, rubber powder and cement powder in a ratio of 100 parts by weight: 12-16 parts by weight: 20-28 parts by weight: 4-9 parts by weight on the surface of the rolling particles for coating, and after completion, drying the obtained product.

2. The high-strength antifreeze macroporous recycled concrete according to claim 1, characterized in that: The particle size of the recycled concrete coarse aggregate is 5-7 mm.

3. The high-strength antifreeze macroporous recycled concrete according to claim 1, characterized in that: The particle size of the antifreeze is 0.4-1.0 mm.

4. The high-strength antifreeze macroporous recycled concrete according to claim 1, characterized in that: The particle size of the glass particles is 20-50 meshes.

5. The high-strength antifreeze macroporous recycled concrete according to claim 1, characterized in that: The glass particles are formed by crushing waste glass.

6. The high-strength antifreeze macroporous recycled concrete according to claim 1, characterized in that: The plastic fiber filaments include at least one of polyvinyl alcohol fiber filaments, polypropylene fiber filaments, and polyester fiber filaments.

7. The high-strength antifreeze macroporous recycled concrete according to claim 1, characterized in that: The length of the plastic fiber filament is 20-40 mm, and the diameter is 0.2-0.6 mm.

8. The high-strength antifreeze macroporous recycled concrete according to claim 1, characterized in that: The ratio of the particles to the coating liquid is 1g:2.5~3.7ml.

9. The high-strength antifreeze macroporous recycled concrete according to claim 1, characterized in that: The product was dried naturally at room temperature for 8 to 12 hours.

10. The high-strength frost-resistant macroporous recycled concrete according to claim 1, characterized in that: The metal thermal conductor includes any one of aluminum powder and copper powder.

11. The high-strength antifreeze macroporous recycled concrete according to claim 1, characterized in that: The particle size of the metal thermal conductor is 400-600 mesh.

12. The high-strength frost-resistant macroporous recycled concrete according to any one of claims 1 to 11, characterized in that: The invention also includes 0.002 to 0.007 parts by weight of an air entraining agent and / or 0.5 to 1.1 parts by weight of a water reducing agent.

13. The high-strength antifreeze macroporous recycled concrete according to claim 12, characterized in that: The air entraining agent includes any one of dodecyl sulfonate, alkylbenzene sulfonate, fatty alcohol polyoxyethylene ether, fatty alcohol polyoxyethylene sulfonate sodium, fatty alcohol sodium sulfate, and methyl cellulose ether.

14. The high-strength antifreeze macroporous recycled concrete according to claim 12, characterized in that: The water reducer includes any one of a polycarboxylate water reducer, a naphthalene water reducer, and a lignin sulfonate water reducer.

15. The method for preparing high-strength frost-resistant macroporous recycled concrete according to any one of claims 1 to 11, characterized in that: The method comprises the following steps: uniformly mixing the cement, fly ash, recycled concrete coarse aggregate, plastic fiber, glass particles, carbon black or iron black, and then adding the antifreeze agent and mixing water and mixing evenly to obtain the product.

16. The method for preparing high-strength frost-resistant macroporous recycled concrete according to any one of claims 12 to 14, characterized in that: The method comprises the following steps: uniformly mixing the cement, fly ash, recycled concrete coarse aggregate, plastic fiber, glass particles, carbon black or iron black and air entraining agent, and then adding the antifreeze agent, water reducing agent and mixing water and mixing evenly to obtain the product.

17. Use of the high-strength frost-resistant macroporous recycled concrete according to any one of claims 1 to 14 or the high-strength frost-resistant macroporous recycled concrete obtained by the preparation method according to any one of claims 15 to 16 in the field of construction engineering or road engineering.

Images