Fabricated thermal insulation firewall based on recycled concrete

Abstract

The invention provides a recycled concrete-based fabricated thermal insulation firewall, which comprises an outer protective shell, an inner protective plate and a middle functional layer, the periphery of the outer protective shell is bonded with the inner protective plate, a cavity is formed between the outer protective shell and the inner protective plate, the middle functional layer is arranged in the cavity, and the outer protective shell and the inner protective plate are bonded through the middle functional layer. The middle functional layer comprises a fireproof isolation layer, an embedded heat preservation material layer and a recycled concrete base body which are sequentially arranged from inside to outside. Wherein the recycled concrete matrix adopts recycled aggregate, the recycled aggregate is obtained by soaking and modifying waste concrete in a modifying solution, and toughening fibers are also added into the recycled concrete matrix. The nano modified recycled aggregate and hybrid fiber reinforcement technology is adopted, the surface performance of the recycled aggregate is improved, the usage amount of the aggregate and cement is remarkably reduced, and the environmental friendliness of the material is improved; the outer protective shell serves as a polyvinyl chloride isolating layer carrier and serves as a mold for pouring recycled concrete, assembly type production is facilitated, and the production and installation efficiency is high.

Description

Technical Field

[0001] The invention relates to a thermal insulation fire wall for buildings, and in particular to an assembled thermal insulation fire wall based on recycled concrete. Background Art

[0002] Traditional concrete walls use virgin aggregate, consuming approximately 1.8 tons of natural stone per cubic meter. This consumes a lot of stone and results in high economic costs. The Chinese invention patent CN114316615B separates the insulation layer from the fireproof layer, increasing the wall thickness by more than 30%. Furthermore, on-site welding connections are inefficient, with an average daily installation volume of less than 10m. 2 While Chinese invention patent application CN118997390A utilizes a recycled concrete and rock wool board design, it fails to address the issue of integrated thermal insulation and fire protection. Chinese invention patent application CN119390404A also utilizes recycled concrete aggregate and fiber reinforcement, but fails to demonstrate superior fire and thermal insulation properties. Therefore, it is necessary to propose an assembled thermal insulation fire wall based on recycled concrete. Summary of the Invention

[0003] The present invention proposes an assembled thermal insulation fire wall based on recycled concrete to solve the problems existing in the prior art.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] A prefabricated thermal insulation fire wall based on recycled concrete includes an outer protective shell, an inner protective plate, and an intermediate functional layer. The outer protective shell is bonded to the inner protective plate on all sides, and a cavity is formed between the outer protective shell and the inner protective plate. The intermediate functional layer is provided in the cavity, and the intermediate functional layer includes a fireproof isolation layer, an embedded thermal insulation material layer, and a recycled concrete matrix, which are arranged in sequence from the inside to the outside.

[0006] Preferably, the recycled concrete matrix comprises 45%-50% by mass of recycled aggregate with a particle size of 5-20 mm, 30-35% by mass of Portland cement, 14-16% by mass of fly ash, and 1.8-2.2% by mass of a water reducer.

[0007] Preferably, the recycled aggregate is obtained by soaking and modifying waste concrete in a modifying liquid, wherein the modifying liquid is a nano-silica sol solution or a potassium silicate solution with a concentration of 5%-8%.

[0008] Preferably, after 24 hours of modification, the porosity of the recycled aggregate is tested to be less than or equal to 12%, and the water absorption rate is less than or equal to 5%.

[0009] Preferably, toughening fibers are further added to the recycled concrete matrix, wherein the toughening fibers are a mixture of basalt fibers and polypropylene fibers, wherein the polypropylene fibers account for 30-50%; alternatively, the toughening fibers are polyvinyl alcohol (PVA) fibers; and the dosage of the toughening fibers is 12-18 kg / m³.

[0010] Preferably, the embedded thermal insulation material layer is a composite layer of vacuum insulation panel and aerogel, with a thermal conductivity of less than or equal to 0.025W / (m·K), a surface density of less than or equal to 1.5kg / m², and a thickness of 15-25mm.

[0011] Preferably, the aerogel in the embedded thermal insulation material layer is a composite of silica aerogel and glass fiber felt.

[0012] Preferably, the fireproof isolation layer is a rock wool board arranged in a double-layer staggered manner with a thickness of 20-30 mm.

[0013] Preferably, the bonding joint between the outer protective shell and the inner protective plate is filled with an expanded graphite-based fireproof sealant, which has a fire resistance limit of greater than or equal to 2 hours and is composed of 60%-70% by mass of graphite and 30%-40% by mass of a silicone rubber matrix.

[0014] Preferably, the recycled concrete matrix and the embedded thermal insulation material layer are separated by a polyvinyl chloride isolation layer.

[0015] Compared with the prior art, the present invention has the following beneficial technical effects:

[0016] 1) This invention utilizes nano-modified recycled aggregate and hybrid fiber reinforcement technology, innovatively utilizing industrial solid waste, such as recycled concrete, as the core raw material for prefabricated walls, replacing traditional cement-based materials. Recycled aggregate is typically made from construction demolition waste, but due to the presence of old mortar on its surface, it has high water absorption and low strength. Modified with a nano-silica sol solution or potassium silicate solution, the nano-silica sol or potassium silicate particles can fill the tiny pores in the recycled aggregate, reducing its porosity and water absorption. The nano-silica sol or potassium silicate particles also undergo a secondary hydration reaction with the hydration products, strengthening the interfacial transition zone. By optimizing their dosage ratios, the use of aggregate and cement can be significantly reduced (reducing carbon emissions), enhancing the material's environmental friendliness. The simultaneous use of fly ash and a high-efficiency water reducer not only addresses the strength challenges of solid waste recycling materials but also enhances the material's density and impermeability through the fly ash's filling effect, further enhancing the wall structure's core thermal insulation / insulation properties. Experiments have demonstrated that this invention exhibits excellent thermal insulation and fire protection properties.

[0017] 2) The outer protective shell serves as a carrier for the thermal insulation layer, innovatively serving as a mold for pouring recycled concrete, facilitating prefabricated production. The multi-layer structure facilitates construction and assembly, ensuring that concrete pouring and curing, along with the thermal insulation layer, do not interfere with each other during production and application, resulting in high production and installation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a structural diagram of the assembled thermal insulation firewall.

[0019] Figure 2 This is a cross-sectional diagram of an assembled thermal insulation firewall.

[0020] Figure 3 This is a graph showing the test results of the porosity and water absorption of the assembled thermal insulation fire wall in Example 1.

[0021] In the figure: outer protective shell 1; inner protective plate 2; middle functional layer 3; recycled concrete matrix 3a; embedded thermal insulation material layer 3b; vacuum insulation panel 3b1; aerogel felt 3b2; fireproof isolation layer 3c. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0023] Example 1:

[0024] This embodiment provides an assembled thermal insulation fire wall based on recycled concrete, which is applied to exterior walls of residences in cold regions.

[0025] Specifically, the assembled thermal insulation fire wall includes an outer protective shell 1, an inner protective plate 2, and an intermediate functional layer 3. The outer protective shell 1 is bonded to the inner protective plate 2 on all sides. A cavity is formed between the outer protective shell 1 and the inner protective plate 2. The intermediate functional layer 3 is provided in the cavity. The intermediate functional layer 3 includes a fireproof isolation layer 3c, an embedded thermal insulation material layer 3b, and a recycled concrete matrix 3a, which are arranged in sequence from the inside to the outside. That is, the fireproof isolation layer 3c is arranged close to the inner protective plate 2, the recycled concrete matrix 3a is arranged away from the inner protective plate 2, and the embedded thermal insulation material layer 3b is arranged between the fireproof isolation layer 3c and the recycled concrete matrix 3a. The "from inside to outside" described in this embodiment is relative to the building. When the assembled thermal insulation fire wall is in use, the inner protective plate 2 faces the inside of the building and the outer protective shell 1 faces the outside of the building.

[0026] Specifically, the recycled concrete matrix comprises 45%-50% by weight of recycled aggregate with a particle size of 5-20 mm, 30-35% by weight of Portland cement, 14-16% by weight of fly ash, and 1.8-2.2% by weight of a water reducer. The recycled aggregate is obtained by soaking waste concrete in a nano-silica sol solution or potassium silicate solution as a modifying fluid, with the concentration of the modifying fluid being 5%-8%.

[0027] In a specific embodiment, recycled aggregate was obtained from C30 waste concrete from a demolition site in Beijing. The recycled aggregate was crushed by jaw crusher and then sieved to a size of 5-20 mm. The recycled aggregate was processed as follows: surface dust removal → magnetic separation → immersion in a nano-silica sol solution (pH = 9.5) for 24 hours → drying at 85°C. After 24 hours of modification, the recycled aggregate was tested according to GB / T 17431.2-2010 to determine a porosity of 12% or less and a water absorption of 5% or less. The concrete mix ratio was: 50% modified recycled aggregate, 30% cement, 15% Grade II fly ash (by weight), and 2% water reducer, using a polycarboxylate superplasticizer.

[0028] Specifically, toughening fibers are added to the recycled concrete matrix. The toughening fibers are a mixture of basalt fibers and polypropylene fibers, with polypropylene fibers accounting for 30-50%. Alternatively, the toughening fibers are polyvinyl alcohol (PVA) fibers. The dosage of the toughening fibers is 12-18 kg / m³.

[0029] In a specific embodiment, the toughening fiber is a mixture of basalt fiber and polypropylene fiber, wherein the polypropylene fiber accounts for 40%, the dosage is 15kg / m³, and the length is 15-25mm.

[0030] Specifically, the embedded insulation material layer is a composite layer of vacuum insulation panels and aerogel, with a thermal conductivity of less than or equal to 0.025 W / (m·K), an areal density of less than or equal to 1.5 kg / m², and a thickness of 15-25 mm. The aerogel is a composite of silica aerogel and glass fiber mat (i.e., aerogel mat).

[0031] In a specific embodiment, the embedded thermal insulation material layer is: 25 mm thick vacuum insulation panel 3b1 (ie, VIP panel, the core material gas phase is SiO2) + 5 mm aerogel felt 3b2.

[0032] Specifically, the recycled concrete matrix 3a and the embedded thermal insulation material layer 3b are separated by a polyvinyl chloride isolation layer, such as a polyvinyl chloride film. The fireproof isolation layer is a double-layer staggered rock wool board with a thickness of 30 mm.

[0033] The assembly process of the prefabricated thermal insulation fire wall is as follows: 1) Place the outer protective shell 1 on the support, pour the recycled concrete matrix 3a onto the outer protective shell 1, and after curing to the specified age, cover it with a polyvinyl chloride isolation layer and bond it with glue; 2) Place a double-layer staggered rock wool board (fireproof isolation layer 3c) on the inner protective plate 2, and then place the embedded thermal insulation material layer 3b on the rock wool board and bond it with glue; 3) Press the outer protective shell 1 onto the inner protective plate 2, and fill the bonding joint with expanded graphite-based fireproof sealant. The fire resistance limit of the sealant is greater than or equal to 2 hours, and the joint injection pressure is 0.4MPa. The components of the sealant are 60-70% by mass of graphite and 30-40% by mass of silicone rubber matrix.

[0034] The compressive strength, fire resistance and heat transfer coefficient test results of the assembled thermal insulation fire wall obtained in this embodiment are shown in Table 1. The water absorption and porosity test results are shown in Table 1. Figure 3 .according to Figure 1 As can be seen, the product's compressive strength reaches 35.6 MPa, meeting the performance of C30 concrete and approaching the level of virgin aggregate C35. Furthermore, while achieving a fire resistance of 3 hours, it also meets the 75% energy saving standard for cold regions in Beijing, achieving a composite and lightweight integration of materials and functions. This means that the prefabricated thermal insulation fire wall in this embodiment exhibits excellent thermal insulation and fire protection properties.

[0035]

[0036] This embodiment achieves a recycled aggregate utilization rate of ≥50%, significantly improved heat transfer coefficient, and a fire resistance limit of 3 hours through the coordinated design of recycled aggregate modified with nano-silica sol, a vacuum insulation panel / aerogel composite insulation layer, and an intermediate fire protection layer composed of double-layer offset rock wool panels. This is particularly suitable for high-rise building exterior wall systems.

[0037] The above description is only used to illustrate the technical solution of the present invention and is not intended to limit it. Any modifications or replacements made to the technical solution by other technicians in this professional field should be included in the scope of the claims of the present invention as long as they do not depart from the connotation of the technical solution of the present invention.

Claims

1. A prefabricated thermal insulation and fireproof prefabricated wall based on recycled concrete, characterized by: It includes an outer protective shell, an inner protective plate, and an intermediate functional layer. The outer protective shell is bonded to the inner protective plate on all sides. A cavity is formed between the outer protective shell and the inner protective plate. The intermediate functional layer is provided in the cavity. The intermediate functional layer includes a fireproof isolation layer, an embedded thermal insulation material layer, and a recycled concrete matrix arranged in sequence from the inside to the outside.

2. The assembled thermal insulation and fireproof assembled wall based on recycled concrete according to claim 1, characterized in that: The recycled concrete matrix comprises 45%-50% by mass of recycled aggregate with a particle size of 5-20 mm, 30-35% by mass of Portland cement, 14-16% by mass of fly ash, and 1.8-2.2% by mass of a water reducer.

3. The assembled thermal insulation and fireproof assembled wall based on recycled concrete according to claim 2, characterized in that: The recycled aggregate is obtained by soaking waste concrete in a modification liquid, wherein the modification liquid is a nano-silica sol solution or a potassium silicate solution with a concentration of 5%-8%.

4. The assembled thermal insulation and fireproof assembled wall based on recycled concrete according to claim 3, characterized in that: After 24 hours of modification, the porosity of the recycled aggregate is less than or equal to 12%, and the water absorption rate is less than or equal to 5%.

5. The assembled thermal insulation and fireproof assembled wall based on recycled concrete according to claim 4, characterized in that: Toughening fibers are also added to the recycled concrete matrix. The toughening fibers are a mixture of basalt fibers and polypropylene fibers, wherein the polypropylene fibers account for 30-50%; alternatively, the toughening fibers are polyvinyl alcohol fibers; and the dosage of the toughening fibers is 12-18 kg / m³.

6. The assembled thermal insulation and fireproof assembled wall based on recycled concrete according to claim 1, characterized in that: The embedded thermal insulation material layer is a composite layer of vacuum insulation panels and aerogel, with a thermal conductivity of less than or equal to 0.025W / (m·K), a surface density of less than or equal to 1.5kg / m², and a thickness of 15-25mm.

7. The assembled thermal insulation and fireproof assembled wall based on recycled concrete according to claim 6, characterized in that: In the embedded thermal insulation material layer, the aerogel is a composite of silica aerogel and glass fiber felt.

8. The assembled thermal insulation and fireproof assembled wall based on recycled concrete according to claim 1, characterized in that: The fireproof isolation layer is a rock wool board, which is arranged in a double-layer staggered manner and has a thickness of 20-30 mm.

9. The assembled thermal insulation and fireproof assembled wall based on recycled concrete according to claim 1, characterized in that: The bonding joint between the outer protective shell and the inner protective plate is filled with an expanded graphite-based fireproof sealant, which has a fire resistance limit of greater than or equal to 2 hours and is composed of 60%-70% by mass of graphite and 30%-40% by mass of a silicone rubber matrix.

10. The assembled thermal insulation and fireproof assembled wall based on recycled concrete according to claim 1, characterized in that: The recycled concrete matrix and the embedded thermal insulation material layer are separated by a polyvinyl chloride isolation layer.

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