Aerated concrete applied to floor sound insulation and heat preservation and a preparation method thereof

Abstract

The application relates to the technical field of floor concrete, and discloses aerated concrete applied to floor sound insulation and heat preservation and a preparation method thereof, aiming at the problems of poor structural stability of aerated concrete, poor long-acting sound insulation effect and mechanical property of existing sound insulation floor containing aerated concrete, and the aerated concrete comprises, in terms of mass fractions, 30-40 parts of fly ash, 25-35 parts of sand, 15-20 parts of phosphogypsum, 10-15 parts of quicklime, 5-8 parts of silicon-aluminum porous microspheres, 3-5 parts of slaked lime, 1-2 parts of Fe3O4@polypropylene fiber and 0.2-0.5 parts of aluminum powder; the preparation method of the silicon-aluminum porous microspheres comprises the following steps: mixing a silicon source, an aluminum source and a surfactant, uniformly stirring, obtaining silicon-aluminum homogenate; then adding nano titanium dioxide, ultrasonic dispersion, freeze-drying, then being transferred into a heating furnace, heating calcination, obtaining silicon-aluminum porous microspheres. The application realizes the support and reinforcement of pores through the gas production reaction in the material, so that the structural strength and durability of the aerated concrete are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of floor concrete, in particular to an aerated concrete applied to floor sound insulation and heat preservation and a preparation method thereof. BACKGROUND

[0002] In the construction industry, the sound insulation performance of the floor impact sound is closely related to the sound transmission path, material properties and structural design. The impact sound generated by the floor mainly includes two paths: one is direct sound transmission, the impact energy directly acts on the surface of the floor, causing structural vibration, which is transmitted to the adjacent space through the floor body, connection nodes and support structure; the other is lateral sound transmission, which spreads to adjacent building components through non-continuous parts such as floor edges, wall connections or pipeline holes, forming a "sound bridge". Therefore, impact sound insulation needs to block the vibration transmission path and consume sound energy, which requires the floor to have high damping and other characteristics.

[0003] To this end, aerated concrete is applied to the research and practice of floor sound insulation due to its lightweight, thermal insulation and other characteristics. For example, the patent with publication number CN116290528A proposes an aerated concrete floor based on UHPC and a construction method thereof. A thermal insulation material is used as a formwork, and a truss reinforcement is inverted and bound in the formwork, with the upper end of the truss reinforcement extending into the formwork and the lower end exposed outside the formwork. The fiber-modified autoclaved aerated concrete material is poured on the side of the formwork with the truss reinforcement, and gasification and cutting are performed to form an aerated concrete blank with truss reinforcement. The aerated concrete blank is heated and pressurized to generate strength and melt the formwork to expose the upper end of the truss reinforcement. The truss reinforcement is connected to the UHPC bottom lining using a buckle connector. The ordinary concrete is post-cast on the fiber-modified autoclaved aerated concrete layer with the UHPC bottom lining to form an aerated concrete floor.

[0004] However, the existing sound insulation floor with aerated concrete as described above still has the following problems: the structural stability of the aerated concrete is poor, which causes the porous structure to deform over time, affecting the impact sound insulation effect, and also causing problems such as degradation of the strength of the floor and shortening of the service life. SUMMARY

[0005] The present application aims to solve the problem of poor structural stability of aerated concrete in existing sound insulation floors containing aerated concrete, i.e., poor long-term effectiveness of sound insulation effect and mechanical properties.

[0006] The present application is achieved by the following technical solutions:

[0007] The present application provides a preparation method of an aerated concrete applied to floor sound insulation and heat preservation, comprising the following steps:

[0008] S1 mixes fly ash, sand, phosphogypsum, quicklime, hydrated lime, Fe3O4@polypropylene fiber and aluminum powder in the specified proportions, injects the mixture into the mold in multiple batches, and simultaneously injects silicon-aluminum porous microspheres. After heat treatment, it obtains initial set concrete.

[0009] S2 places the initially set concrete in a magnetic field, applies a uniform magnetic field, then transfers it to a heater for heating treatment, and then cools it at a uniform rate of 5-12℃ / h to obtain the aerated concrete.

[0010] Preferably, in step S1, the mass of the injected silicon-aluminum porous microspheres increases gradually in a gradient.

[0011] Preferably, in step S1, the heating temperature is 40-50℃, and the holding time after heating is 1-2 hours; in step S2, the heating temperature is 80-95℃, and the holding time after heating is 3-5 hours.

[0012] Preferably, in step S1, the fiber length of Fe3O4@polypropylene fiber is 20-200 mm, and the micropore particle size of the silicon-aluminum porous microspheres is 50-200 μm.

[0013] Preferably, by weight, it includes 30-40 parts fly ash, 25-35 parts sand, 15-20 parts phosphogypsum, 10-15 parts quicklime, 3-12 parts porous silica-alumina microspheres, 3-5 parts hydrated lime, 1-2 parts Fe3O4@polypropylene fiber, and 0.2-0.5 parts aluminum powder.

[0014] Preferably, the method for preparing the porous silicon-aluminum microspheres includes the following steps:

[0015] A silicon source, an aluminum source, and a surfactant are mixed and stirred until homogeneous to obtain a silicon-aluminum slurry. Nano-titanium dioxide is then added, ultrasonically dispersed, freeze-dried, and then transferred to a heating furnace for calcination to obtain the silicon-aluminum porous microspheres. The molar ratio of silicon source, aluminum source, and surfactant is 2.5-3.5:0.8-1.2:0.1-0.2.

[0016] Preferably, the amount of nano-titanium dioxide added is 2-10 wt% of the total mass of the silicon-aluminum homogenate.

[0017] Preferably, the freezing temperature is -80℃ to -50℃ and the freezing time is 0.5-3h; the calcination temperature is 500-800℃ and the calcination time is 1.5-5h.

[0018] The aerated concrete prepared by the above-mentioned method for sound insulation and thermal insulation of floor slabs has a porosity of 75-85%, a compressive strength ≥5.6MPa, a flexural strength ≥5.2MPa, and an impact sound insulation ≤62dB.

[0019] The technical solution of the present invention has the following beneficial effects:

[0020] This invention introduces porous silica-alumina microspheres and Fe3O4@polypropylene fibers into aerated concrete to enhance the stability of its pore structure, thereby improving its structural strength and durability. Specifically, firstly, porous silica-alumina microspheres are added in a gradient manner. The hydration and gas-generating properties of these microspheres form uniform secondary pores, which act as a framework to support the primary pores. This gradient porosity effectively increases the frequency range of sound absorption in the aerated concrete while maintaining its lightweight properties. Secondly, a magnetic field is applied to orient the magnetic fibers in the raw materials, guiding the pores along the stress direction and reducing the risk of pore collapse. Furthermore, the polypropylene in the magnetic fibers has good elasticity, which weakens the internal stiffness of the concrete, thus improving its sound insulation effect against impact noise. Finally, segmented low-temperature initial setting and high-temperature curing optimize and control the pore formation process, enhancing pore stability and improving the stability and supporting strength of the aerated concrete over time. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, they are performed according to conventional conditions or conditions recommended by the manufacturer; where the manufacturers of the instruments, equipment, reagents, or raw materials used are not specified, they are all conventional products that can be purchased commercially.

[0022] This invention provides an aerated concrete for sound insulation and thermal insulation of floor slabs, comprising, by weight, 30-40 parts fly ash, 25-35 parts sand, 15-20 parts phosphogypsum, 10-15 parts quicklime, 3-12 parts porous silica-alumina microspheres, 3-5 parts hydrated lime, 1-2 parts Fe3O4@polypropylene fiber, and 0.2-0.5 parts aluminum powder.

[0023] The preparation method of porous silica-alumina microspheres includes the following steps:

[0024] The silicon source, aluminum source, and surfactant are mixed and stirred evenly to obtain a silicon-aluminum slurry. Nano-titanium dioxide is then added and ultrasonically dispersed for 30-60 minutes. The mixture is then frozen at -80℃ to -50℃ for 0.5-3 hours and dried for 10-12 hours. The mixture is then transferred to a heating furnace and heated to 500-800℃ for calcination for 1.5-5 hours to form porous silicon-aluminum microspheres with micropores of 50-200 μm.

[0025] Fe3O4@polypropylene fiber is made by blending magnetic iron oxide powder with polypropylene and then melt spinning it. The length of Fe3O4@polypropylene fiber is 20-200mm.

[0026] The aerated concrete of the present invention, applied to sound insulation and thermal insulation of floor slabs, is prepared by the following steps:

[0027] (1) First, mix fly ash, sand, phosphogypsum, quicklime, hydrated lime, Fe3O4@polypropylene fiber and aluminum powder in the specified amounts, stir evenly, and inject into the mold in multiple batches. Each time the mold is injected, silicon-aluminum porous microspheres are added simultaneously, and the amount of silicon-aluminum porous microspheres added increases gradually to form pores with gradient content. Heat to 40-50℃ and keep warm for 1-2 hours. During this process, the low temperature can promote the slow gas production of silicon-aluminum porous microspheres, forming uniform secondary pores, and the entire material system achieves initial solidification.

[0028] (2) Apply a 0.5-1T vertical magnetic field to align Fe3O4@polypropylene fibers along the direction of the magnetic field, guide the pores to form longitudinal channels, reduce transverse stress concentration, and maintain the uniformity and stability of the pores in the aerated concrete; heat to 80-95℃ and keep warm for 3-5 hours to solidify the material system, while the silicon-aluminum porous microspheres continue to produce gas and fill the collapsed pores.

[0029] (3) Place the cured material under a pressure of 1-1.5MPa and cool it at a uniform rate of 5-12℃ / h to avoid thermal stress damaging the pore structure until it is cooled and formed, and then you can get aerated concrete that can be used as a floor slab.

[0030] The aerated concrete prepared by the present invention using the above-mentioned raw materials and methods has a porosity of 75-85%, a compressive strength ≥5.6MPa, a flexural strength ≥5.2MPa, and an impact sound insulation ≤62dB.

[0031] Example 1

[0032] Step 1: Mix 178.5g of tetraethyl orthosilicate (TEOS), 75.0g of aluminum nitrate, and 22.3g of cetyltrimethylammonium bromide, and stir at 200r / min for 45min to form a silicon-aluminum homogenate. Then add 31.7g of titanium dioxide powder with an average particle size of 5nm to the silicon-aluminum homogenate, and ultrasonically disperse for 10min. Then freeze at -50℃ for 45min, and dry for 10h. Finally, place it in a heating furnace, heat to 550℃, calcine for 3h, and cool to room temperature to obtain porous silicon-aluminum microspheres. The average pore size was measured to be approximately 135μm.

[0033] Step 2: Take nano-magnetic iron oxide powder and polypropylene powder that have passed through a 200-mesh sieve at a mass ratio of 1:9, and melt spin them into Fe3O4@polypropylene fibers with a length range of 40-80mm.

[0034] Step 3: By weight, take 35.8 parts fly ash, 26 parts cement sand, 16.5 parts phosphogypsum, 12 parts quicklime, 3.5 parts hydrated lime, 1.45 parts Fe3O4@polypropylene fiber and 0.3 parts aluminum powder, and stir at 80 r / min for 45 min to obtain the initial slurry, which is then ready for use.

[0035] Step 4: The initial slurry is injected into the mold in three parts, and each injection of the initial slurry is accompanied by the injection of porous silica-alumina microspheres. The mass fractions of the porous silica-alumina microspheres injected in the three injections are 1 part, 2 parts and 3 parts. Then, the mold is heated to 50°C and kept warm for 1.5 hours to form initial set concrete with gradient porosity.

[0036] Step 5: Place the initial set concrete in a uniform magnetic field device and apply a vertical magnetic field of 0.8T; then transfer it to a heating chamber, heat it to 90℃, keep it at that temperature for 3.5h, and then transfer it to a 1.2MPa pressure environment and cool it down at a constant pressure of 8℃ / h to obtain aerated concrete material.

[0037] Example 2

[0038] Step 1: Mix 178.5g of tetraethyl orthosilicate (TEOS), 75.0g of aluminum nitrate, and 22.3g of cetyltrimethylammonium bromide, and stir at 200r / min for 45min to form a silicon-aluminum homogenate. Then add 31.7g of titanium dioxide powder with an average particle size of 5nm to the silicon-aluminum homogenate, and ultrasonically disperse for 10min. Then freeze at -50℃ for 45min, and dry for 10h. Finally, place it in a heating furnace, heat to 550℃, calcine for 3h, and cool to room temperature to obtain porous silicon-aluminum microspheres. The average pore size was measured to be approximately 135μm.

[0039] Step 2: Take nano-magnetic iron oxide powder and polypropylene powder that have passed through a 200-mesh sieve at a mass ratio of 1:9, and produce Fe3O4@polypropylene fiber by melt spinning.

[0040] Step 3: By weight, take 35.8 parts fly ash, 26 parts cement sand, 16.5 parts phosphogypsum, 12 parts quicklime, 3.5 parts hydrated lime, 1 part Fe3O4@polypropylene fiber and 0.3 parts aluminum powder, and stir at 80 r / min for 45 min to obtain the initial slurry, which is then ready for use.

[0041] Step 4: The initial slurry is injected into the mold in three parts, and each injection of the initial slurry is accompanied by the injection of porous silica-alumina microspheres. The mass fractions of the porous silica-alumina microspheres injected in the three injections are 0.5 parts, 1.5 parts and 2.5 parts. Then, the mixture is heated to 50°C and kept at that temperature for 1.5 hours to form initial set concrete with gradient porosity.

[0042] Step 5: Place the initial set concrete in a uniform magnetic field device and apply a vertical magnetic field of 0.8T; then transfer it to a heating chamber, heat it to 90℃, keep it at that temperature for 3.5h, and then transfer it to a 1.2MPa pressure environment and cool it down at a constant pressure of 8℃ / h to obtain aerated concrete material.

[0043] Example 3

[0044] Step 1: Mix 178.5g of tetraethyl orthosilicate (TEOS), 75.0g of aluminum nitrate, and 22.3g of cetyltrimethylammonium bromide, and stir at 200r / min for 45min to form a silicon-aluminum homogenate. Then add 31.7g of titanium dioxide powder with an average particle size of 5nm to the silicon-aluminum homogenate, and ultrasonically disperse for 10min. Then freeze at -50℃ for 45min, and dry for 10h. Finally, place it in a heating furnace, heat to 550℃, calcine for 3h, and cool to room temperature to obtain porous silicon-aluminum microspheres. The average pore size was measured to be approximately 135μm.

[0045] Step 2: Take nano-magnetic iron oxide powder and polypropylene powder that have passed through a 200-mesh sieve at a mass ratio of 1:9, and produce Fe3O4@polypropylene fiber by melt spinning.

[0046] Step 3: By weight, take 35.8 parts fly ash, 26 parts cement sand, 16.5 parts phosphogypsum, 12 parts quicklime, 3.5 parts hydrated lime, 1.85 parts Fe3O4@polypropylene fiber and 0.3 parts aluminum powder, and stir at 80 r / min for 45 min to obtain the initial slurry, which is then ready for use.

[0047] Step 4: The initial slurry is injected into the mold in three batches, and each batch of initial slurry is accompanied by the injection of porous silica-alumina microspheres. The mass fractions of the porous silica-alumina microspheres injected in the three batches are 2 parts, 4 parts and 6 parts respectively. Then, the mixture is heated to 50°C and kept at that temperature for 1.5 hours to form initial set concrete with a gradient porosity.

[0048] Step 5: Place the initial set concrete in a uniform magnetic field device and apply a vertical magnetic field of 0.8T; then transfer it to a heating chamber, heat it to 90℃, keep it at that temperature for 3.5h, and then transfer it to a 1.2MPa pressure environment and cool it down at a constant pressure of 8℃ / h to obtain aerated concrete material.

[0049] Example 4

[0050] Step 1: Mix 178.5g of tetraethyl orthosilicate (TEOS), 75.0g of aluminum nitrate, and 17.5g of cetyltrimethylammonium bromide, and stir at 200r / min for 45min to form a silicon-aluminum homogenate. Then add 31.7g of titanium dioxide powder with an average particle size of 5nm to the silicon-aluminum homogenate, and ultrasonically disperse for 10min. Then freeze at -50℃ for 45min, and dry for 10h. Finally, place it in a heating furnace, heat to 500℃, calcine for 1h, and cool to room temperature to obtain porous silicon-aluminum microspheres. The average pore size was measured to be approximately 135μm.

[0051] Step 2: Take nano-magnetic iron oxide powder and polypropylene powder that have passed through a 200-mesh sieve at a mass ratio of 1:9, and produce Fe3O4@polypropylene fiber by melt spinning.

[0052] Step 3: By weight, take 35.8 parts fly ash, 26 parts cement sand, 16.5 parts phosphogypsum, 12 parts quicklime, 3.5 parts hydrated lime, 1.5 parts Fe3O4@polypropylene fiber and 0.3 parts aluminum powder, and stir at 80 r / min for 45 min to obtain the initial slurry, which is then ready for use.

[0053] Step 4: Inject the initial slurry into the mold in two batches, and at the same time as each injection of the initial slurry, inject 2 parts and 5 parts by mass of porous silica-alumina microspheres. Then heat to 50°C and keep warm for 1 hour to form initial set concrete with gradient porosity.

[0054] Step 5: Place the initial set concrete in a uniform magnetic field device and apply a vertical magnetic field of 0.8T; then transfer it to a heating chamber, heat it to 90℃, keep it at that temperature for 3.5h, and then transfer it to a 1.2MPa pressure environment and cool it down at a constant pressure of 8℃ / h to obtain aerated concrete material.

[0055] Comparative Example 1

[0056] Step 1: Take 35.8 parts fly ash, 26 parts cement sand, 16.5 parts phosphogypsum, 12 parts quicklime, 3.5 parts hydrated lime and 0.3 parts aluminum powder by weight, and stir at 80 r / min for 45 min to obtain the initial slurry, which is then ready for use.

[0057] Step 2: The initial slurry is injected into the mold in three batches, then heated to 50°C and kept warm for 1.5 hours; then it is transferred to a heating chamber, heated to 90°C and kept warm for 3.5 hours, and then transferred to a 1.2MPa pressure environment and cooled at a constant pressure of 8°C / h to obtain the aerated concrete material.

[0058] Comparative Example 2

[0059] Step 1: Take nano-magnetic iron oxide powder and polypropylene powder that have passed through a 200-mesh sieve at a mass ratio of 1:9, and melt spin them to produce Fe3O4@polypropylene fibers with a length range of 40-80mm.

[0060] Step 2: By weight, take 35.8 parts fly ash, 26 parts cement sand, 16.5 parts phosphogypsum, 12 parts quicklime, 4 parts tetraethyl orthosilicate, 3.5 parts hydrated lime, 2 parts aluminum nitrate, 0.6 parts hexadecyltrimethylammonium bromide, 0.2 parts Fe3O4@polypropylene fiber, and 0.3 parts aluminum powder. Stir at 80 r / min for 45 min to obtain the initial slurry, and set aside for later use.

[0061] Step 3: The initial slurry is injected into the mold in three batches, and each batch of initial slurry is accompanied by the injection of porous silica-alumina microspheres. The mass fractions of the porous silica-alumina microspheres injected in the three batches are 1 part, 2 parts and 3 parts. Then, the mixture is heated to 50°C and kept at that temperature for 1.5 hours to form initial set concrete with gradient porosity.

[0062] Step 4: Place the initial set concrete in a uniform magnetic field device and apply a vertical magnetic field of 0.8T; then transfer it to a heating chamber, heat it to 90℃, keep it at that temperature for 3.5h, and then transfer it to a 1.2MPa pressure environment and cool it down at a constant pressure of 8℃ / h to obtain aerated concrete material.

[0063] Test case

[0064] The aerated concrete materials prepared in Examples 1 to 4 and Comparative Examples 1 to 2 were taken as samples. The mechanical properties and sound insulation effects of these samples were determined according to the requirements of GB / T 29756-2013 "Test Method for Flexural and Compressive Strength of Hardened Mortar" and GB / T 19889.6-2005 "Sound Insulation Measurement of Acoustic Buildings and Building Components". The results are summarized in Table 1 below:

[0065] Table 1 Performance test results of different samples

[0066] Comparative Example 1 Comparative Example 2 Porosity (%) Compressive strength (MPa) Flexural strength (MPa) Impact sound insulation (dB) ​ ​ 82 71 84 79 48 55 ​ 6.2 5.7 5.6 6.0 5.1 5.3 ​ 5.5 5.2 5.3 5.5 4.7 4.4 ​ 53 58 57 62 72 70

[0067] The test results above show that the aerated concrete materials prepared in Examples 1 to 4 exhibit significantly better overall strength and impact sound insulation performance than those in Comparative Examples 1 and 2. This demonstrates that the aerated concrete and its preparation method proposed in this invention can significantly improve the sound insulation and absorption performance of floor slabs in practical applications, and its significantly enhanced strength allows for more effective support and stability.

[0068] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for producing an aerated concrete for sound insulation and thermal insulation of a floor, characterized by, Comprising the following steps: S1 uniformly mixing fly ash, sand, phosphogypsum, quicklime, slaked lime, Fe3O4@ polypropylene fiber and aluminum powder according to the amount, injecting into the mold in multiple times, the mass of silica-alumina porous microspheres is increased gradually each time, and silica-alumina porous microspheres are injected at the same time, heating treatment, heating temperature is 40-50℃, and the holding time after heating is 1-2h, to obtain initial setting concrete; The fiber length of Fe3O4@ polypropylene fiber is 20-200mm, and the micropore particle size of the silica-alumina porous microspheres is 50-200μm; S2 placing the initial setting concrete in a magnetic field, applying a uniform magnetic field, the magnetic field condition is 0.5-1T vertical magnetic field, then transferring into a heater, heating treatment, heating temperature is 80-95℃, and the holding time after heating is 3-5h, and then cooling at a uniform speed of 5-12℃ / h, to obtain the aerated concrete.

2. The method for producing the aerated concrete for sound and heat insulation of a floor according to claim 1, characterized in that, According to mass fraction, comprising 30-40 parts of fly ash, 25-35 parts of sand, 15-20 parts of phosphogypsum, 10-15 parts of quicklime, 3-5 parts of silica-alumina porous microspheres, 3-5 parts of slaked lime, 1-2 parts of Fe3O4@ polypropylene fiber and 0.2-0.5 parts of aluminum powder.

3. The method for producing the aerated concrete for sound and heat insulation of a floor according to claim 2, characterized in that, The preparation method of the silica-alumina porous microspheres comprises the following steps: Mixing the silicon source, aluminum source and surfactant, stirring uniformly to obtain a silica-alumina homogenate, then adding nano titanium dioxide, ultrasonic dispersion, freeze-drying, then transferring into a heating furnace, heating calcination to obtain the silica-alumina porous microspheres; The molar ratio of the silicon source, aluminum source and surfactant is 2.5-3.5:0.8-1.2:0.1-0.

2.

4. The method for producing the aerated concrete for sound and heat insulation of a floor according to claim 3, characterized in that, The addition amount of nano titanium dioxide is 2-10wt% of the total mass of the silica-alumina homogenate.

5. The method for producing the aerated concrete for sound and heat insulation of a floor according to claim 3, characterized in that, The freezing temperature is-80℃ to-50℃, and the freezing time is 0.5-3h; the calcination temperature is 500-800℃, and the calcination time is 1.5-5h.

6. An aerated concrete for use in sound and thermal insulation of floors, characterized in that, Prepared by the preparation method of any one of claims 1 to 5.

7. The aerated concrete for sound insulation and thermal insulation of floors according to claim 6, characterized in that, The porosity of the aerated concrete is 75-85%, the compressive strength is ≥5.6MPa, the flexural strength is ≥5.2MPa, and the impact sound insulation amount is ≤62dB.