Thermal insulation aerated rubber recycled concrete block and preparation method thereof

Abstract

The invention discloses a thermal insulation aerated rubber recycled concrete block and a preparation method thereof, and belongs to the technical field of concrete block preparation. Comprising the following raw materials in parts by weight: 100 parts of cement, 92-153 parts of natural coarse aggregate, 153-215 parts of recycled coarse aggregate, 80-141 parts of natural fine aggregate, 16-33 parts of modified waste rubber particles and 0.1-0.3 part of sodium abietate. According to the invention, the waste concrete is fully utilized, the cost is saved, the construction waste is effectively consumed, and the carbon emission is reduced; and through the introduction of sodium abietate, a large number of uniform and closed microbubbles are introduced into a concrete mixture, so that the heat preservation property of the concrete block is remarkably improved, and meanwhile, the workability of the mixture is improved.

Description

Technical Field

[0001] This application belongs to the field of concrete block preparation technology, and specifically relates to a thermal insulation aerated rubber recycled concrete block and its preparation method. Background Technology

[0002] With the acceleration of urbanization, the demand for indoor temperature control equipment such as air conditioners and heating systems has increased significantly, leading to a surge in energy consumption. Ordinary concrete blocks, due to their high thermal conductivity, low specific heat capacity, and poor insulation performance, result in low efficiency of indoor temperature control equipment, further exacerbating energy consumption. Therefore, improving the insulation performance of concrete has significant environmental benefits and engineering implications.

[0003] The development of recycled concrete technology stems primarily from the urgent need for resource utilization and sustainable development of construction waste. With the deepening of urbanization and urban renewal in my country, the generation of large amounts of construction waste has brought enormous environmental pressure; simultaneously, the over-exploitation of natural sand and gravel resources has triggered a resource depletion crisis. Against this backdrop, processing waste concrete blocks through crushing, screening, and strengthening to produce recycled aggregates for use in the preparation of new concrete has become a key technological path to turning construction waste into a valuable resource. This technology not only aims to dispose of solid waste but also strives to ensure that recycled concrete meets structural engineering requirements through optimized mix proportions and aggregate strengthening, thereby promoting the transformation of the construction industry towards a green and low-carbon direction.

[0004] Waste lightweight rubber, as a super-elastic organic material, possesses lightweight and wear-resistant properties. Its ability to replace fine aggregates in the concrete mixing process in granular form creates a porous structure in rubber concrete. This effectively increases the air content of the original concrete, thereby improving its thermal insulation performance and leveraging its advantages. It not only alleviates some of the rubber pollution problem but also demonstrates significant research potential in combining waste rubber and recycled aggregates—two renewable materials—to create novel recycled concrete blocks.

[0005] In recycled rubber concrete, significant interfacial compatibility issues exist between hydrophobic rubber particles and the hydrophilic cement matrix and recycled aggregates, leading to a weak interfacial transition zone and reduced strength—key shortcomings. Silane coupling agents, acting as molecular bridges, possess a unique amphiphilic structure. One end of this structure forms a strong chemical bond with inorganic materials (such as cement hydration products and aggregates), while the other end exhibits good compatibility or entanglement with organic materials (rubber particles). Through this efficient bridging effect, silane coupling agents can significantly enhance the interfacial adhesion between components, thereby effectively improving the strength of the composite material and further enhancing its mechanical properties by improving density. Summary of the Invention

[0006] To address the aforementioned issues, this application provides a thermally insulated aerated rubber recycled concrete block and its preparation method.

[0007] The first objective of this application is to provide a thermally insulated aerated rubber recycled concrete block, comprising the following raw materials in parts by weight: 100 parts cement, 92-153 parts natural coarse aggregate, 153-215 parts recycled coarse aggregate, 80-141 parts natural fine aggregate, 16-33 parts modified waste rubber granules, and 0.1-0.3 parts sodium rosinate.

[0008] In a specific embodiment of this application, the thermal insulation and aerated rubber recycled concrete block comprises the following raw materials in parts by weight: 100 parts cement, 153 parts natural coarse aggregate, 153 parts recycled coarse aggregate, 141 parts natural fine aggregate, 24 parts modified waste rubber granules, and 0.1 parts sodium rosinate.

[0009] In a specific embodiment of this application, the thermal insulation and aerated rubber recycled concrete block comprises the following raw materials in parts by weight: 100 parts cement, 127 parts natural coarse aggregate, 180 parts recycled coarse aggregate, 90 parts natural fine aggregate, 24 parts modified waste rubber granules, and 0.2 parts sodium rosinate.

[0010] In a specific embodiment of this application, the thermal insulation and aerated rubber recycled concrete block comprises the following raw materials in parts by weight: 100 parts cement, 95 parts natural coarse aggregate, 200 parts recycled coarse aggregate, 120 parts natural fine aggregate, 32 parts modified waste rubber granules, and 0.3 parts sodium rosinate.

[0011] In a specific embodiment of this application, the recycled coarse aggregate is continuously graded crushed stone obtained by screening crushed construction waste, with a particle size of 5-25 mm.

[0012] In a specific embodiment of this application, the natural coarse aggregate is continuously graded limestone crushed stone with a particle size of 5-25 mm.

[0013] In a specific embodiment of this application, the natural fine aggregate is continuously graded natural river sand with a particle size of 0.075 to 4.75 mm.

[0014] In specific embodiments of this application, the particle size of the modified waste rubber particles is 1-3 mm.

[0015] In a specific embodiment of this application, the modified waste rubber particles are waste rubber particles with silane coupling agent surface modification, and the waste rubber particles are obtained by crushing waste tires.

[0016] In a specific embodiment of this application, the method for preparing the modified waste rubber particles includes: Waste rubber granules are soaked in a silane coupling agent solution for 1-2 hours and then dried at 50-70℃ to obtain modified waste rubber granules. The silane coupling agent solution is composed of silane coupling agent, water, and ethanol in a mass ratio of 1-3:20-25:65-80.

[0017] In a specific embodiment of this application, the mass ratio of the waste rubber particles to the silane coupling agent is 10:1-3.

[0018] In a specific example of this application, the silane coupling agent is KH-550.

[0019] Silane coupling agents can significantly enhance the interfacial bond between rubber and cement matrix, effectively improve the mechanical property loss caused by rubber incorporation, and improve the strength of concrete blocks. They are a key technology for achieving high-performance aerated rubber recycled concrete blocks.

[0020] The second objective of this application is to provide a method for preparing thermally insulated aerated rubber recycled concrete blocks, comprising: The recycled coarse aggregate is soaked to obtain water-saturated recycled coarse aggregate; The water-saturated recycled coarse aggregate and natural coarse aggregate are stirred and mixed evenly to obtain the first mixture; Natural fine aggregate and modified waste rubber granules are stirred and mixed evenly to obtain a second mixture; After the first and second mixtures are mixed evenly, water and an aqueous solution of sodium rosinate are added, and stirring is continued. After being stirred evenly, the mixture is shaped, dried, demolded, and cured to obtain thermal insulation and aerated rubber recycled concrete blocks.

[0021] In a specific embodiment of this application, the mass of water added is 30-50% of the mass of cement added. Preferably, the mass of water added is 50% of the mass of cement. In a specific embodiment of this application, the mass fraction of the aqueous solution of sodium rosinate is 8-12%.

[0022] Compared with the prior art, this application has the following advantages: This application discloses an insulated aerated rubber recycled concrete block and its preparation method, which makes full use of waste concrete, saves costs, effectively disposes of construction waste, and reduces carbon emissions. Using waste rubber granules can significantly improve the toughness, impact resistance and crack resistance of materials, while reducing the material's own weight and improving the thermal insulation effect, providing an effective way for the resource utilization of waste tires; The introduction of sodium rosinate introduces a large number of uniform, closed microbubbles into the concrete mixture, which significantly improves the thermal insulation of the concrete blocks and enhances the workability of the mixture.

[0023] Other features and advantages of this application will be set forth in the following description and will be apparent in part from the description or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures indicated in the description. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below in conjunction with the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0025] In the embodiments of this application, the cement used is PO 42.5 grade ordinary Portland cement produced by Huaxin Cement Ezhou Co., Ltd.; the natural fine aggregate is continuously graded natural river sand with a particle size of 0.075-4.75 mm and a fineness modulus of 2.62; the natural coarse aggregate is continuously graded limestone crushed stone with a particle size of 5-25 mm; the recycled coarse aggregate is continuously graded coarse aggregate obtained by crushing and screening construction waste with a particle size of 5-25 mm; the rubber granules are made from crushed waste tires with a particle size of 1-3 mm; the silane coupling agent is KH-550; and the sodium rosinate is anionic surfactant in solid powder form.

[0026] Example 1 The mass ratio of each raw material in the aerated rubber recycled concrete block is 1:1.53:1.53:1.41:0.5:0.24:0.001.

[0027] The method for preparing the aerated rubber recycled concrete blocks includes the following steps: 1) Weigh out all the required raw materials according to the corresponding mixing ratio; 2) Soak the weighed recycled coarse aggregate and rubber granules for 24 hours and drain the water until they reach water saturation.

[0028] 3) Rinse the rubber granules with water and dry them for later use. Prepare a silane coupling agent solution by mixing silane coupling agent, anhydrous ethanol and water in a ratio of 2:76:22. Pour the silane coupling agent solution into the rubber granules and let the rubber granules soak in the solution for 1 hour. Then drain the rubber granules and dry them in a dryer at 60°C. 4) Dissolve sodium rosinate powder in warm water (40-60℃), mix well, and prepare a 10% sodium rosinate solution stock solution for later use; 5) Mix natural fine aggregate and rubber granules evenly to obtain mixture I, and mix natural coarse aggregate and recycled coarse aggregate evenly to obtain mixture II; 6) After mixing mixture I, mixture II and cement, stir for 60-90 seconds. Add the mixing water and the prepared 10% sodium rosinate mother liquor to the mixer and stir for 180-240 seconds to obtain the mixture of aerated rubber recycled concrete blocks. 7) The mixture of the aerated rubber recycled concrete blocks is molded, demolded, and cured to obtain aerated rubber recycled concrete blocks.

[0029] Example 2 The mass ratio of each raw material in the aerated rubber recycled concrete block is 1:1.27:1.80:9.0:0.5:0.24:0.002.

[0030] The method for preparing the aerated rubber recycled concrete blocks includes the following steps: 1) Weigh out all the required raw materials according to the corresponding mixing ratio; 2) Soak the weighed recycled coarse aggregate and rubber granules for 24 hours and drain the water until they reach water saturation.

[0031] 3) Rinse the rubber granules with water and dry them for later use. Prepare a silane coupling agent solution by mixing silane coupling agent, anhydrous ethanol and water in a ratio of 1:74:25. Pour the silane coupling agent solution into the rubber granules and let the rubber granules soak in the solution for 1 hour. Then drain the rubber granules and dry them in a dryer at 60°C. 4) Dissolve sodium rosinate powder in warm water (40-60℃), mix well, and prepare an 8% sodium rosinate solution stock solution for later use; 5) Mix natural fine aggregate and rubber granules evenly to obtain mixture I, and mix natural coarse aggregate and recycled coarse aggregate evenly to obtain mixture II; 6) After mixing mixture I, mixture II and cement, stir for 60-90 seconds. Add the mixing water and the prepared 10% sodium rosinate mother liquor to the mixer and stir for 180-240 seconds to obtain the mixture of thermal insulation aerated rubber recycled concrete blocks. 7) The mixture of the thermal insulation aerated rubber recycled concrete block is molded, demolded, and cured to obtain the aerated rubber recycled concrete block.

[0032] Example 3 The mass ratio of each raw material in the thermal insulation and aerated rubber recycled concrete block is: cement: natural coarse aggregate: recycled coarse aggregate: natural fine aggregate: water: (pre-treated) waste rubber granules: (solid) sodium rosinate, which is 1:0.95:2.00:1.20:0.5:0.32:0.003.

[0033] The method for preparing the aforementioned thermal insulation and aerated rubber recycled concrete blocks includes the following steps: 1) Weigh out all the required raw materials according to the corresponding mixing ratio; 2) Soak the weighed recycled coarse aggregate and rubber granules for 24 hours and drain the water until they reach water saturation.

[0034] 3) Rinse the rubber granules with water and dry them for later use. Prepare a silane coupling agent solution by mixing silane coupling agent, anhydrous ethanol and water in a ratio of 3:75:22. Pour the silane coupling agent solution into the rubber granules and let the rubber granules soak in the solution for 1 hour. Then drain the rubber granules and dry them in a dryer at 60°C. 4) Dissolve sodium rosinate powder and water in warm water (40-60℃) at a mass ratio of 1:9, mix well, and prepare a 12% sodium rosinate solution stock solution for later use. 5) Mix natural fine aggregate and rubber granules evenly to obtain mixture I, and mix natural coarse aggregate and recycled coarse aggregate evenly to obtain mixture II; 6) After mixing mixture I, mixture II and cement, stir for 60-90 seconds. Add the mixing water and the prepared 10% sodium rosinate mother liquor to the mixer and stir for 180-240 seconds to obtain the mixture of thermal insulation aerated rubber recycled concrete blocks. 7) The mixture of the thermal insulation and aerated rubber recycled concrete blocks is molded, demolded, and cured to obtain thermal insulation and aerated rubber recycled concrete blocks.

[0035] Comparative Example 1 The mass ratio of each raw material in the recycled rubber concrete block is: cement: natural coarse aggregate: recycled coarse aggregate: natural fine aggregate: recycled fine aggregate: (untreated) waste rubber particles: water: polycarboxylate superplasticizer = 1: 1.48: 1.48: 0.80: 0.48: 0.32: 0.46: 0.026.

[0036] The method for preparing the aforementioned recycled rubber concrete blocks includes the following steps: 1) Weigh out all the required raw materials according to the corresponding mixing ratio.

[0037] 2) Soak the weighed recycled coarse aggregate, recycled fine aggregate, and rubber granules for 24 hours, and drain the water until they reach water saturation.

[0038] 3) Mix natural fine aggregate and rubber granules evenly to obtain mixture I; mix natural coarse aggregate and recycled coarse aggregate evenly to obtain mixture II; dissolve polycarboxylate superplasticizer in water to obtain mixture III; 4) After mixing mixture I, mixture II and cement, stir for 60-90 seconds, then add mixture III and stir for 240-300 seconds to obtain rubber recycled concrete block mixture; Comparative Example 2 The mass ratio of each raw material in the recycled rubber concrete block is: cement: natural coarse aggregate: recycled coarse aggregate: natural fine aggregate: water: (pre-treated) waste rubber particles, which is 1:1.53:1.53:1.41:0.5:0.24.

[0039] The method for preparing the aforementioned recycled rubber concrete blocks includes the following steps: 1) Weigh out all the required raw materials according to the corresponding mixing ratio; 2) Soak the weighed recycled coarse aggregate and rubber granules for 24 hours and drain the water until they reach water saturation.

[0040] 3) Rinse the rubber granules with water and dry them for later use. Prepare a silane coupling agent solution by mixing silane coupling agent, anhydrous ethanol and deionized water in a ratio of 2:76:22. Pour the silane coupling agent solution into the rubber granules and let the rubber granules soak in the solution for 1 hour. Then drain the rubber granules and dry them in a dryer at 60°C. 4) Mix natural fine aggregate and rubber granules evenly to obtain mixture I, and mix natural coarse aggregate and recycled coarse aggregate evenly to obtain mixture II; 5) After mixing mixture I, mixture II and cement, stir for 60-90 seconds, add mixing water to the mixer, and stir for 180-240 seconds to obtain the mixture of rubber recycled concrete blocks; 6) The mixture of the rubber recycled concrete blocks is molded, demolded, and cured to obtain rubber recycled concrete blocks.

[0041] Comparative Example 3 The mass ratio of each raw material in the aerated rubber recycled concrete block is 1:1.53:1.53:1.41:0.5:0.24:0.0001.

[0042] The method for preparing the aerated rubber recycled concrete blocks includes the following steps: 1) Weigh out all the required raw materials according to the corresponding mixing ratio; 2) Soak the weighed recycled coarse aggregate and rubber granules for 24 hours and drain the water until they reach water saturation.

[0043] 3) Rinse the rubber granules with water and dry them for later use. Prepare a silane coupling agent solution by mixing silane coupling agent, anhydrous ethanol and water in a ratio of 2:76:22. Pour the silane coupling agent solution into the rubber granules and let the rubber granules soak in the solution for 1 hour. Then drain the rubber granules and dry them in a dryer at 60°C. 4) Dissolve sodium rosinate powder in warm water (40-60℃) and mix well to prepare a 10% sodium rosinate solution stock solution for later use; 5) Mix natural fine aggregate and rubber granules evenly to obtain mixture I, and mix natural coarse aggregate and recycled coarse aggregate evenly to obtain mixture II; 6) After mixing mixture I, mixture II and cement, stir for 60-90 seconds. Add the mixing water and the prepared 10% sodium rosinate mother liquor to the mixer and stir for 240-300 seconds to obtain the mixture of aerated rubber recycled concrete blocks. 7) The mixture of the aerated rubber recycled concrete blocks is molded, demolded, and cured to obtain aerated rubber recycled concrete blocks.

[0044] Performance tests were conducted on 28-day compressive strength, thermal conductivity, and apparent density for Examples 1 to 3 and Comparative Examples 1 to 3. The test results are shown in Table 1.

[0045] Table 1

[0046] As can be seen from Table 1, the thermal conductivity of the recycled concrete blocks obtained in Examples 1 to 3 of this application is lower than that of Comparative Examples 1 to 3, indicating that the recycled concrete blocks obtained in Examples 1 to 3 of this application have excellent thermal insulation performance.

[0047] Although the introduction of sodium rosinate leads to a decrease in the 28-day compressive strength of the recycled concrete blocks, the strength of the recycled concrete blocks obtained in Examples 1 to 3 is above 19.9, which meets the requirements for use in thermal insulation mixed soil.

[0048] Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A thermally insulated, aerated rubber recycled concrete block, characterized in that, The raw materials include the following parts by weight: 100 parts cement, 92-153 parts natural coarse aggregate, 153-215 parts recycled coarse aggregate, 80-141 parts natural fine aggregate, 16-33 parts modified waste rubber granules, and 0.1-0.3 parts sodium rosinate.

2. The thermally insulated aerated rubber recycled concrete block according to claim 1, characterized in that, The recycled coarse aggregate is continuously graded crushed stone obtained by screening crushed construction waste, with a particle size of 5-25 mm.

3. The thermally insulated aerated rubber recycled concrete block according to claim 1, characterized in that, The natural coarse aggregate is continuously graded limestone crushed stone with a particle size of 5–25 mm.

4. The thermally insulated aerated rubber recycled concrete block according to claim 1, characterized in that, The natural fine aggregate is continuously graded natural river sand with a particle size of 0.075–4.75 mm.

5. The thermally insulated aerated rubber recycled concrete block according to claim 1, characterized in that, The particle sizes of the modified waste rubber particles are 1 to 3 mm.

6. The thermally insulated aerated rubber recycled concrete block according to claim 1, characterized in that, The modified waste rubber particles are waste rubber particles with surface modification by silane coupling agent.

7. A thermal insulation and aerated rubber recycled concrete block according to any one of claims 1-6, wherein the thermal insulation and aerated rubber recycled concrete block comprises the following raw materials in parts by weight: 100 parts cement, 153 parts natural coarse aggregate, 153 parts recycled coarse aggregate, 141 parts natural fine aggregate, 24 parts modified waste rubber granules, and 0.1 parts sodium rosinate. Alternatively, the thermal insulation and aerated rubber recycled concrete block comprises the following raw materials in parts by weight: 100 parts cement, 127 parts natural coarse aggregate, 180 parts recycled coarse aggregate, 90 parts natural fine aggregate, 24 parts modified waste rubber granules, and 0.2 parts sodium rosinate. Alternatively, the thermal insulation and aerated rubber recycled concrete block comprises the following raw materials in parts by weight: 100 parts cement, 95 parts natural coarse aggregate, 200 parts recycled coarse aggregate, 120 parts natural fine aggregate, 32 parts modified waste rubber granules, and 0.3 parts sodium rosinate.

8. A method for preparing a thermally insulated, aerated rubber recycled concrete block according to any one of claims 1-7, characterized in that, include: The recycled coarse aggregate is soaked to obtain water-saturated recycled coarse aggregate; The water-saturated recycled coarse aggregate and natural coarse aggregate are stirred and mixed evenly to obtain the first mixture; Natural fine aggregate and modified waste rubber granules are stirred and mixed evenly to obtain a second mixture; After the first and second mixtures are mixed evenly, water and an aqueous solution of sodium rosinate are added, and stirring is continued. After being stirred evenly, the mixture is shaped, dried, demolded, and cured to obtain thermal insulation and aerated rubber recycled concrete blocks.

9. The method for preparing a thermally insulated, aerated rubber recycled concrete block according to claim 8, characterized in that, The mass of the added water is 46-50% of the mass of the cement.

10. The method for preparing a thermally insulated aerated rubber recycled concrete block according to claim 8, characterized in that, The aqueous solution of sodium rosinate has a mass fraction of 8-12%.

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