Glass fiber reinforced aerated concrete and its preparation process

Abstract

The present application relates to the field of concrete preparation technology, and specifically discloses a glass fiber reinforced aerated concrete and its preparation process. A glass fiber reinforced aerated concrete, including the following components of raw materials: 20-30 parts of cement; 10-20 parts of fly ash; 15-25 parts of quicklime; 30-40 parts of silica sand; 0.1-0.3 parts of aluminum powder; 0.5-1.5 parts of foaming agent; 0.5-1 parts of foam stabilizer; 1-3 parts of modified glass fiber; 25-35 parts of water; the modified glass fiber is obtained by nano-titanium dioxide particles forming an ordered nanocomposite layer on the surface of the glass fiber through molecular self-assembly. The aerated concrete of the present application introduces modified glass fiber, which not only enhances the bonding force between the glass fiber and the concrete matrix, but also significantly improves the creep resistance of the glass fiber itself, thereby effectively enhancing the compressive strength and crack resistance of the aerated concrete.

Description

Technical Field

[0001] The present application relates to the technical field of concrete preparation, and more specifically, to a glass fiber reinforced aerated concrete and a preparation process thereof. Background Art

[0002] Aerated concrete is a lightweight, porous silicate product made primarily from siliceous and calcareous materials, mixed with a gas-generating agent, through a series of processes, including batching, mixing, pouring, pre-curing, cutting, autoclaving, and curing. It's named aerated concrete because it contains a large number of uniform, fine pores after aeration. Aerated concrete offers excellent thermal insulation properties, making it convenient and cost-effective for constructing self-insulating walls. It is a sustainable, green building material that conserves energy, land, and waste. Its low production, construction, and heating energy consumption make it the most thermally economical wall material.

[0003] In related art, Chinese patent publication CN104557107B discloses a lightweight autoclaved aerated concrete and its preparation method. The concrete is made from quartz sand, quicklime, cement, gypsum, and aluminum paste as its main raw materials, along with inorganic fiber and grinding aids. The specific ratios are: 60-70 parts quartz sand, 18-25 parts quicklime, 9-13 parts cement, 2-3 parts gypsum, 0.28-0.32 parts aluminum paste, 0.3-0.6 parts inorganic fiber, and 3-6 parts grinding aid. The resulting concrete has a density of 300-325 kg / m³. The preparation steps are briefly described as follows: First, weigh the raw materials in proportion and set aside. Then, add water to the quartz sand and a grinding aid, and wet-grind in a ball mill to produce a quartz mortar. Next, crush and grind the quicklime blocks to produce quicklime powder, and add water to the gypsum to produce a gypsum slurry. The aluminum paste and inorganic fiber are mixed and then stirred with water until uniform. Afterwards, quartz mortar and gypsum slurry are added to the pouring mixer, mixed and stirred while controlling the temperature. Cement and quicklime powder are then added and mixed evenly. Finally, a mixture of aluminum powder paste and inorganic fiber is added. The entire slurry is stirred and poured. After pouring, it is pre-cured at a certain temperature for a period of time, then demolded and cut to obtain the desired green body. Finally, the green body is cured in high-temperature, high-pressure steam, sampled and inspected, packaged and stored, and naturally cured to obtain the finished product. By adding a certain proportion of inorganic fiber and adjusting the preparation process, this concrete significantly improves the material's shrinkage and compressive strength while ensuring a low product density.

[0004] In the aforementioned technologies, aerated concrete enhances its compressive strength and crack resistance by adding inorganic fibers such as glass fibers. However, glass fibers are susceptible to creep deformation under prolonged load. Creep is a gradual process; over time, the glass fibers undergo continuous plastic deformation under stress. Because aerated concrete is porous, while the pores reduce the material's weight, they also provide additional space for the glass fibers to creep. When the glass fibers creep within these pores, the deformation is exacerbated by the presence of the pores, leading to a decrease in the glass fiber's performance. Due to the accumulated deformation and decreased performance of the fibers, the concrete is unable to effectively distribute and bear the load through the fibers when under pressure, resulting in a decrease in compressive strength. Furthermore, glass fibers inherently strengthen and disperse stress in concrete, helping to prevent cracking. However, creep deformation weakens this function, resulting in a decrease in the concrete's crack resistance. As creep progresses, the bond between the fibers and the concrete weakens, making the concrete more susceptible to cracking. Therefore, aerated concrete in the related art suffers from poor compressive strength and crack resistance. Summary of the Invention

[0005] In order to enhance the compressive strength and crack resistance of aerated concrete, the present application provides a glass fiber reinforced aerated concrete and a preparation process thereof.

[0006] The glass fiber reinforced aerated concrete provided in this application adopts the following technical solution:

[0007] A glass fiber reinforced aerated concrete, comprising the following raw materials:

[0008] 20-30 parts of cement;

[0009] 10-20 parts fly ash;

[0010] 15-25 parts of quicklime;

[0011] 30-40 parts of silica sand;

[0012] Aluminum powder 0.1-0.3 parts;

[0013] 0.5-1.5 parts of foaming agent;

[0014] 0.5-1 part of foam stabilizer;

[0015] 1-3 parts of modified glass fiber;

[0016] 25-35 parts water;

[0017] The modified glass fiber is obtained by forming an ordered nano composite layer on the surface of the glass fiber through molecular self-assembly of nano titanium dioxide particles.

[0018] By adopting the above technical solution, cement serves as the primary cementitious material, providing basic strength and adhesion to concrete. The gel structure formed by its hydration products tightly binds the other raw materials. Fly ash has pozzolanic activity, which not only improves the workability of concrete and reduces the heat of hydration, but also undergoes a secondary reaction with calcium hydroxide in the cement hydration products in the later stage to produce more gel substances such as hydrated calcium silicate, thereby improving the durability of concrete. Quicklime and silica sand react chemically in an alkaline environment to produce products such as hydrated calcium silicate with gelling properties, further enhancing the strength of concrete. Aluminum powder acts as a gas-generating agent, reacting with alkaline substances in the system to produce hydrogen. This hydrogen forms a large number of evenly distributed tiny pores within the concrete, giving the aerated concrete its lightweight properties while also optimizing its thermal insulation properties.

[0019] The modified glass fiber is one of the core innovations of this application. It significantly enhances the performance of the glass fiber by forming an ordered nanocomposite layer on the surface of the glass fiber through molecular self-assembly of nano-titanium dioxide particles. From a microscopic perspective, the nano-titanium dioxide particles have a high specific surface area and excellent mechanical properties. When the nano-titanium dioxide particles form a composite layer on the surface of the glass fiber through molecular self-assembly, multiple interactions are formed between the nano-particles and the glass fiber. On the one hand, the active groups on the surface of the nano-titanium dioxide particles are connected to the groups on the surface of the glass fiber through chemical bonding, forming a stable chemical connection; on the other hand, there are strong intermolecular forces such as van der Waals forces between the nano-particles and the glass fiber. These interactions enhance the interaction between the molecular chains in the glass fiber, making the molecular chains less likely to slip and deform when subjected to external forces, thereby effectively reducing creep deformation. In traditional aerated concrete, the reinforcing effect of glass fiber gradually weakens over time due to creep. However, the modified glass fiber of this application can continuously and effectively disperse stress under long-term stress conditions due to its stable nanocomposite layer structure. When aerated concrete is subjected to pressure, the modified glass fiber can evenly distribute the load throughout the concrete matrix, avoiding stress concentration and significantly improving the compressive strength of the aerated concrete. In terms of crack resistance, the modified glass fiber can restrain the deformation of the concrete matrix. When tensile stress is generated within the concrete, the modified glass fiber can bear part of the tensile stress, preventing the formation and expansion of cracks, thereby enhancing the crack resistance of the aerated concrete.

[0020] Optionally, the modified glass fiber is prepared by the following steps:

[0021] A. Tetrabutyl titanate was added dropwise to anhydrous ethanol and mixed under magnetic stirring to form solution A;

[0022] B. Deionized water, anhydrous ethanol and glacial acetic acid are mixed to form solution B. Solution A and solution B are taken at a volume ratio of 1:1. Solution B is added dropwise to solution A under stirring at a dropping rate of 1 drop / second. After the addition is completed, stirring is continued for 1-3 hours to obtain a nano-titanium dioxide sol;

[0023] C. Aging, drying, and calcining the nano-titanium dioxide sol to obtain nano-titanium dioxide particles;

[0024] D. adding the nano-titanium dioxide particles to a toluene solution containing 3-aminopropyltrimethoxysilane at a concentration of 0.1-0.3 mol / L, and reflux reacting at 80° C. for 4-6 hours. After the reaction, washing with anhydrous ethanol, centrifuging, and drying to obtain amino-grafted nano-titanium dioxide particles;

[0025] E. Sodium lauryl sulfate, amino-grafted nano-titanium dioxide particles and aluminum triisopropoxide are mixed to obtain a reaction solution, and then the pH value of the reaction solution is adjusted to 6.5 with a dilute hydrochloric acid solution, and then glass fiber is added. Then, the reaction is stirred at 40-50° C. and a speed of 200 r / min for 3-5 hours to obtain modified glass fiber.

[0026] By adopting the above technical solution, tetrabutyl titanate is first dissolved in anhydrous ethanol to form solution A. Anhydrous ethanol can not only evenly disperse tetrabutyl titanate, but also regulate its hydrolysis rate, forming a homogeneous system through magnetic stirring. Deionized water, anhydrous ethanol and glacial acetic acid are mixed to form solution B, and solution A is added dropwise at a specific speed. Deionized water participates in the hydrolysis reaction, while glacial acetic acid inhibits excessive hydrolysis, controlling the formation of nano-titanium dioxide sol. The dropwise addition rate and stirring time are precisely controlled to ensure the quality of the sol. The sol is aged, dried and calcined. Aging allows the particles to grow and aggregate, drying removes moisture, and calcination improves crystallinity and stability, resulting in high-quality nano-titanium dioxide particles. Next, the nano-titanium dioxide particles react with 3-aminopropyltrimethoxysilane in a toluene solution. The siloxy groups condense with the hydroxyl groups on the particle surface, successfully grafting amino groups and providing active sites for subsequent self-assembly.

[0027] Finally, utilizing the micellar structure formed by sodium dodecyl sulfate (SDS) in solution, aluminum triisopropoxide, as a catalyst, promotes the stable formation of the SDS micelle structure and facilitates the interaction of the nano-titanium dioxide particles with the glass fiber surface. SDS forms micelles in solution, with its hydrophilic head facing outward in contact with water and its hydrophobic tail facing inward. When the glass fiber is immersed in the solution, the SDS micelles adsorb onto the surface, altering the physicochemical properties of the glass fiber surface. Furthermore, the surface amino groups of the nano-titanium dioxide particles interact with the SDS micelles and the glass fiber surface in various ways, such as hydrogen bonding and electrostatic interactions. The catalytic action of aluminum triisopropoxide further enhances these interactions, allowing the nano-titanium dioxide particles to be more rapidly and stably attracted to the glass fiber surface. Under heating and stirring conditions, driven by these intermolecular interactions, the nano-titanium dioxide particles gradually arrange themselves in an orderly fashion around the SDS micelles surrounding the glass fiber surface. Over time, the nanoparticles become further fixed to each other and to the glass fiber surface through chemical bonding (such as the chemical bonds formed after grafting with silane coupling agents) and stronger intermolecular forces, forming a tightly bound and structurally ordered nanocomposite layer. This nanocomposite layer greatly enhances the creep resistance of the glass fiber, allowing it to better play its reinforcing role in aerated concrete.

[0028] Optionally, in step A, the volume ratio of tetrabutyl titanate to anhydrous ethanol is 1:(3-5).

[0029] By adopting the above technical solution, the above ratio ensures that tetrabutyl titanate has good solubility and dispersibility in anhydrous ethanol, while moderately controlling the hydrolysis rate, which is conducive to forming a uniform and stable sol system.

[0030] Optionally, in step B, the volume ratio of deionized water, anhydrous ethanol and glacial acetic acid is 5:(4-6):2.

[0031] By adopting the above technical solution, the above ratio control ensures the balance of hydrolysis and polycondensation reactions, and the content of glacial acetic acid effectively inhibits particle agglomeration, which helps to form a nano-titanium dioxide sol with uniform particle size and stable performance.

[0032] Optionally, in step D, the mass ratio of the nano-titanium dioxide particles to the toluene solution containing 3-aminopropyltrimethoxysilane is 1:(3-5).

[0033] In the step D, the mass ratio of the nano-titanium dioxide particles to the toluene solution containing 3-aminopropyltrimethoxysilane is preferably 1:4.

[0034] By adopting the above technical solution, the above mass ratio ensures that the grafting reaction is fully carried out, so that sufficient amino groups are successfully grafted onto the surface of the nano-titanium dioxide particles, providing conditions for subsequent self-assembly.

[0035] Optionally, in step E, the mass ratio of sodium lauryl sulfate, amino-grafted nano-titanium dioxide particles and aluminum triisopropoxide is 5:10:3.

[0036] By adopting the above technical solution, the above mass ratio ensures that a uniform and dense nano-composite layer is formed on the surface of the glass fiber, thereby enhancing the creep resistance of the glass fiber.

[0037] Optionally, the foaming agent is any one of hydrogen peroxide, azodicarbonamide and sodium bicarbonate.

[0038] By adopting the above technical solution, the foaming agent can produce uniform and fine bubbles when reacting with other raw materials, optimize the pore structure of aerated concrete, and cooperate with modified glass fiber to reduce the deformation of glass fiber in the pores, thereby improving the strength and crack resistance of aerated concrete.

[0039] Optionally, the foam stabilizer is any one of calcium stearate, sodium dodecylbenzenesulfonate and polyvinyl alcohol.

[0040] By adopting the above technical solution, the foam stabilizer can stabilize the bubbles generated during the foaming process, making the pore structure of the aerated concrete more stable, improving the stress conditions of the glass fiber therein, and synergizing with the modified glass fiber to enhance the performance of the aerated concrete.

[0041] The present application also provides a method for preparing glass fiber reinforced aerated concrete, which adopts the following technical solution:

[0042] A method for preparing glass fiber reinforced aerated concrete comprises the following steps:

[0043] S1. Mix the modified glass fiber with water and stir at a speed of 200 r / min for 3-5 minutes to obtain a fiber suspension;

[0044] S2. Add cement, fly ash, quicklime, silica sand, aluminum powder, foaming agent, and foam stabilizer into a mixer and stir for 3-5 minutes. Then add the fiber suspension and continue stirring for 10-15 minutes to obtain a uniform slurry. The stirring speed is 200 r / min.

[0045] S3. The slurry is injected into a mold and foamed at a temperature of 40-50° C. for 3-5 hours. The slurry is stirred every 30 minutes during the foaming process. After the foaming is completed, the slurry is cured to obtain glass fiber reinforced aerated concrete.

[0046] In summary, this application has the following beneficial effects:

[0047] 1. This application achieves a significant improvement in the mechanical properties of aerated concrete by introducing modified glass fiber. Modified glass fiber is an ordered nano-titanium dioxide composite layer formed on the surface of glass fiber by molecular self-assembly technology. This structure not only enhances the bonding force between the glass fiber and the concrete matrix, but also significantly improves the creep resistance of the glass fiber itself. When the concrete is subjected to external forces, the modified glass fiber can effectively disperse the stress and prevent material damage caused by stress concentration. At the same time, the presence of the nano-composite layer also enhances the toughness of the glass fiber, enabling it to better constrain the deformation of the concrete matrix, thereby significantly improving the compressive strength and crack resistance of the aerated concrete. The application of this innovative technology enables aerated concrete to exhibit more excellent mechanical properties when subjected to heavy loads or complex stress environments.

[0048] 2. This application achieves the optimization of the pore structure of aerated concrete by precisely controlling the raw material ratio and preparation process. Reasonable pore distribution not only gives aerated concrete excellent properties such as light weight and thermal insulation, but also provides favorable conditions for the uniform distribution of modified glass fibers. During the preparation process, the synergistic effect of the foaming agent and the foam stabilizer causes a large number of uniform and fine bubbles to form inside the concrete. These bubbles not only improve the thermal insulation performance of the material, but also reduce the deformation and stress concentration of the glass fibers in the pores. Therefore, the optimized pore structure enables aerated concrete to maintain its lightweight characteristics while significantly improving its overall performance.

[0049] 3. The glass fiber-reinforced aerated concrete preparation process of this application is simple and efficient, and the raw material costs are controllable. During the preparation process, the raw materials are evenly mixed in a certain proportion, and a simple stirring and foaming process is used to obtain an aerated concrete material with excellent performance. In addition, the preparation process of the modified glass fiber is also relatively simple, and an orderly nanocomposite layer can be formed on the glass fiber surface through molecular self-assembly technology. This preparation process not only reduces production costs but also improves production efficiency, making this material have good application prospects in the field of building materials. DETAILED DESCRIPTION

[0050] The present application is further described in detail below with reference to the embodiments.

[0051] Preparation example of modified glass fiber

[0052] Preparation Example 1

[0053] The modified glass fiber is prepared by the following steps:

[0054] A. Add 10 mL of tetrabutyl titanate dropwise to 30 mL of anhydrous ethanol and stir at 500 r / min for 30 min under magnetic stirring to form solution A.

[0055] B. Mix 5 mL of deionized water, 4 mL of anhydrous ethanol, and 2 mL of glacial acetic acid to form solution B. Take 10 mL of solution A and 10 mL of solution B respectively. Add solution B dropwise to solution A under stirring at 200 r / min. The dropping speed is controlled at 1 drop / second. After the addition is completed, continue stirring and reacting for 1 hour to obtain a nano-titanium dioxide sol;

[0056] C. Aging the nano-titanium dioxide sol at 60° C. for 24 hours, then drying it at 80° C. for 12 hours, and finally calcining it at 500° C. for 3 hours to obtain nano-titanium dioxide particles;

[0057] D. Add 10 g of nano-titanium dioxide particles to 30 g of a toluene solution containing 3-aminopropyltrimethoxysilane (concentration: 0.1 mol / L) and reflux at 80°C for 4 h. After the reaction, wash with anhydrous ethanol three times for 10 min each, then centrifuge at 5000 rpm for 5 min and dry at 60°C for 6 h to obtain amino-grafted nano-titanium dioxide particles.

[0058] E. Weigh 5 g of sodium lauryl sulfate, 10 g of amino-grafted nano-titanium dioxide particles, and 3 g of aluminum triisopropoxide to obtain a reaction solution, adjust the pH value of the reaction solution to 6.5 with a dilute hydrochloric acid solution, then add 5 g of glass fiber, and then stir the reaction at 40°C and 200 r / min for 3 h to obtain modified glass fiber.

[0059] Preparation Example 2

[0060] The modified glass fiber is prepared by the following steps:

[0061] A. Add 10 mL of tetrabutyl titanate dropwise to 40 mL of anhydrous ethanol and stir at 500 r / min for 30 min under magnetic stirring to form solution A.

[0062] B. Mix 5 mL of deionized water, 5 mL of anhydrous ethanol, and 2 mL of glacial acetic acid to form solution B. Take 10 mL of solution A and 10 mL of solution B respectively. Add solution B dropwise to solution A under stirring at 200 r / min. The dropping speed is controlled at 1 drop / second. After the addition is completed, continue stirring and reacting for 2 hours to obtain a nano-titanium dioxide sol;

[0063] C. Aging the nano-titanium dioxide sol at 60° C. for 24 hours, then drying it at 80° C. for 12 hours, and finally calcining it at 500° C. for 3 hours to obtain nano-titanium dioxide particles;

[0064] D. Add 10 g of nano-titanium dioxide particles to 40 g of a toluene solution containing 3-aminopropyltrimethoxysilane (concentration: 0.2 mol / L) and reflux at 80°C for 5 h. After the reaction, wash the solution with anhydrous ethanol three times for 10 min each, then centrifuge at 5000 rpm for 5 min and dry at 60°C for 6 h to obtain amino-grafted nano-titanium dioxide particles.

[0065] E. Weigh 5 g of sodium lauryl sulfate, 10 g of amino-grafted nano-titanium dioxide particles, and 3 g of aluminum triisopropoxide to obtain a reaction solution, adjust the pH value of the reaction solution to 6.5 with a dilute hydrochloric acid solution, then add 5 g of glass fiber, and then stir the reaction at 45°C and 200 r / min for 4 h to obtain modified glass fiber.

[0066] Preparation Example 3

[0067] The modified glass fiber is prepared by the following steps:

[0068] A. Add 10 mL of tetrabutyl titanate dropwise to 50 mL of anhydrous ethanol and stir at 500 rpm for 30 min under magnetic stirring to form solution A.

[0069] B. Mix 5 mL of deionized water, 6 mL of anhydrous ethanol, and 2 mL of glacial acetic acid to form solution B. Take 10 mL of solution A and 10 mL of solution B respectively. Add solution B dropwise to solution A under stirring at 200 r / min. The dropping speed is controlled at 1 drop / second. After the addition is completed, continue stirring and reacting for 3 hours to obtain a nano-titanium dioxide sol;

[0070] C. Aging the nano-titanium dioxide sol at 60° C. for 24 hours, then drying it at 80° C. for 12 hours, and finally calcining it at 500° C. for 3 hours to obtain nano-titanium dioxide particles;

[0071] D. Add 10 g of nano-titanium dioxide particles to 50 g of a toluene solution containing 3-aminopropyltrimethoxysilane (concentration: 0.3 mol / L) and reflux at 80°C for 6 h. After the reaction, wash with anhydrous ethanol three times for 10 min each, then centrifuge at 5000 rpm for 5 min, and dry at 60°C for 6 h to obtain amino-grafted nano-titanium dioxide particles.

[0072] E. Weigh 5 g of sodium lauryl sulfate, 10 g of amino-grafted nano-titanium dioxide particles, and 3 g of aluminum triisopropoxide to obtain a reaction solution, adjust the pH value of the reaction solution to 6.5 with a dilute hydrochloric acid solution, then add 5 g of glass fiber, and then stir the reaction at 50°C and 200 r / min for 5 h to obtain modified glass fiber.

[0073] Preparation Example 4

[0074] The modified glass fiber is different from Preparation Example 3 in that aluminum triisopropoxide is not added in step E of this Preparation Example. Specifically, step E is as follows:

[0075] 5 g of sodium lauryl sulfate and 10 g of amino-grafted nano-titanium dioxide particles were weighed and mixed to obtain a reaction solution. The pH value of the reaction solution was adjusted to 6.5 with a dilute hydrochloric acid solution, and then 5 g of glass fiber was added. The mixture was stirred at 50° C. and 200 r / min for 5 h to obtain modified glass fiber.

[0076] The other steps are the same as those in Preparation Example 3.

[0077] Preparation Example 5

[0078] The modified glass fiber differs from Preparation Example 3 in that step D is not performed in this Preparation Example, i.e., amino grafting is not performed on the nano-titanium dioxide particles. In the subsequent step E, the nano-titanium dioxide particles are directly used to participate in the reaction. The other preparation steps are the same as those in Preparation Example 3.

[0079] Preparation Example 6

[0080] The modified glass fiber is different from Preparation Example 3 in that the reaction solution in step E of this Preparation Example is stirred at 200 r / min at 30°C for 5 hours to obtain the modified glass fiber. The other preparation steps are the same as Preparation Example 3.

[0081] Preparation Example 7

[0082] The difference between the modified asbestos fiber and Preparation Example 3 is that in step E of this Preparation Example, an equal amount of asbestos fiber is used instead of glass fiber to participate in the reaction.

[0083] Example

[0084] Example 1

[0085] A glass fiber reinforced aerated concrete, the raw material components and amounts of which are shown in Table 1, wherein hydrogen peroxide is selected as the foaming agent; calcium stearate is selected as the foam stabilizer; and the modified glass fiber is selected from the modified glass fiber prepared in Preparation Example 1.

[0086] A glass fiber reinforced aerated concrete, the preparation method of which is as follows:

[0087] S1. Mixing the modified glass fiber with water and stirring at a speed of 200 r / min for 3 min to obtain a fiber suspension;

[0088] S2. Add cement, fly ash, quicklime, silica sand, aluminum powder, foaming agent and foam stabilizer into a mixer and stir for 3 minutes. Then add the fiber suspension and continue stirring for 10 minutes to obtain a uniform slurry. The stirring speed is 200 r / min.

[0089] S3. The slurry is injected into a mold and foamed at a temperature of 40° C. for 3 hours. Stirring is performed every 30 minutes during the foaming process. After the foaming is completed, the slurry is cured to obtain glass fiber reinforced aerated concrete.

[0090] Example 2

[0091] A glass fiber reinforced aerated concrete, the raw material components and amounts of which are shown in Table 1, wherein azodicarbonamide is selected as the foaming agent; sodium dodecylbenzenesulfonate is selected as the foam stabilizer; and the modified glass fiber is selected from the modified glass fiber prepared in Preparation Example 2.

[0092] A glass fiber reinforced aerated concrete, the preparation method of which is as follows:

[0093] S1. Mixing the modified glass fiber with water and stirring at a speed of 200 r / min for 4 min to obtain a fiber suspension;

[0094] S2. Add cement, fly ash, quicklime, silica sand, aluminum powder, foaming agent and foam stabilizer into a mixer and stir for 4 minutes. Then add the fiber suspension and continue stirring for 13 minutes to obtain a uniform slurry. The stirring speed is 200 r / min.

[0095] S3. The slurry is injected into a mold and foamed at a temperature of 45° C. for 4 hours. Stirring is performed every 30 minutes during the foaming process. After the foaming is completed, the slurry is cured to obtain glass fiber reinforced aerated concrete.

[0096] Example 3

[0097] A glass fiber reinforced aerated concrete, the raw material components and amounts of which are shown in Table 1, wherein sodium bicarbonate is selected as the foaming agent; polyvinyl alcohol is selected as the foam stabilizer; and the modified glass fiber is selected from the modified glass fiber prepared in Preparation Example 3.

[0098] A glass fiber reinforced aerated concrete, the preparation method of which is as follows:

[0099] S1. Mixing the modified glass fiber with water and stirring at a speed of 200 r / min for 5 min to obtain a fiber suspension;

[0100] S2. Add cement, fly ash, quicklime, silica sand, aluminum powder, foaming agent and foam stabilizer into a mixer and stir for 5 minutes. Then add the fiber suspension and continue stirring for 15 minutes to obtain a uniform slurry. The stirring speed is 200 r / min.

[0101] S3. The slurry is injected into a mold and foamed at a temperature of 50° C. for 5 hours. Stirring is performed every 30 minutes during the foaming process. After the foaming is completed, the slurry is cured to obtain glass fiber reinforced aerated concrete.

[0102] Table 1 Concrete components and amounts in Examples 1-3 (g)

[0103]

[0104] Example 4

[0105] A glass fiber reinforced aerated concrete is disclosed. The difference from Example 1 is that the modified glass fiber in this example is the modified glass fiber prepared in Preparation Example 4.

[0106] Example 5

[0107] A glass fiber reinforced aerated concrete is disclosed. The difference from Example 1 is that the modified glass fiber in this example is the modified glass fiber prepared in Preparation Example 5.

[0108] Example 6

[0109] A glass fiber reinforced aerated concrete is disclosed. The difference from Example 1 is that the modified glass fiber in this example is the modified glass fiber prepared in Preparation Example 6.

[0110] Comparative Example

[0111] Comparative Example 1

[0112] A glass fiber reinforced aerated concrete, which differs from Example 1 in that an equal amount of unmodified glass fiber is used instead of modified glass fiber in this comparative example.

[0113] Comparative Example 2

[0114] A glass fiber reinforced aerated concrete is disclosed. The difference from Example 1 is that the modified asbestos fiber prepared in Preparation Example 7 is used instead of the modified glass fiber in this comparative example.

[0115] Comparative Example 3

[0116] A glass fiber reinforced aerated concrete is prepared in accordance with Example 1, which differs from Example 1 in that the amount of modified glass fiber used in this comparative example is 5 g.

[0117] Performance testing

[0118] Compressive strength testing

[0119] Test object: aerated concrete prepared in Examples 1-6 and Comparative Examples 1-3.

[0120] Test method: According to GB / T11969-2020 "Test method for properties of autoclaved aerated concrete", the prepared aerated concrete was cut into 100mm×100mm×100mm cubic specimens, and cured to the specified age at (20±2)℃ and relative humidity (60±5)%. Then, the specimen was loaded at a speed of (2.0±0.5) kN / s on a pressure testing machine until it was destroyed. The failure load was recorded and the compressive strength was calculated.

[0121] Test results: See Table 2.

[0122] Crack resistance testing

[0123] Test object: aerated concrete prepared in Examples 1-6 and Comparative Examples 1-3.

[0124] Testing method: Using the ring method, aerated concrete is made into a ring specimen with an outer diameter of 200mm, an inner diameter of 100mm, and a height of 50mm. Uniform radial tension is applied to the center of the specimen. The appearance and expansion of cracks on the surface of the specimen are monitored by a displacement sensor, and the tension value when the crack appears is recorded as an indicator of crack resistance.

[0125] Test results: See Table 2.

[0126] Table 2 Test results of Examples 1-6 and Comparative Examples 1-3

[0127]

[0128] The modified glass fibers prepared using the complete process in Examples 1-3 function effectively in aerated concrete. From the perspective of reducing creep, the nanocomposite layer on the surface of the modified glass fibers enhances the force between the molecular chains and reduces the creep deformation of the glass fibers. When aerated concrete is subjected to stress, it can continuously disperse stress, which is directly reflected in the compressive strength and crack resistance. In Example 1, because fly ash and other raw materials work well together to generate more hydrated calcium silicate gel, the concrete structure is denser, and the modified glass fibers have a better anchoring effect therein, further suppressing creep, with the compressive strength reaching 5.83 MPa and the crack resistance reaching 4.62 kN. Although the raw material ratios in Examples 2 and 3 have changed, they still maintain relatively high performance, indicating that raw material adjustments within a reasonable range will not affect the core role of modified glass fibers in reducing creep and enhancing performance.

[0129] In Example 4, aluminum triisopropoxide was not added during the preparation of the modified glass fiber. Aluminum triisopropoxide promotes the stable formation of sodium dodecyl sulfate (SDS) micelle structures during the modification process, facilitating the interaction between the nano-titanium dioxide particles and the glass fiber surface. However, the absence of aluminum triisopropoxide results in incomplete formation of the nanocomposite layer, significantly reducing the reinforcing effect of the modified glass fiber. This reduced the compressive strength of the aerated concrete to 4.35 MPa and the crack resistance to 3.10 kN.

[0130] In Example 5, amino grafting was not performed on the nano-titanium dioxide particles. Amino grafting is a key step in providing active sites for subsequent self-assembly. Without amino grafting, it is difficult for the nano-titanium dioxide particles to form a stable bond with the glass fibers, failing to effectively enhance the performance of the glass fibers. The resulting aerated concrete had a compressive strength of only 3.80 MPa and a crack resistance of 2.65 kN.

[0131] In Example 6, during the preparation of modified glass fiber, the reaction solution temperature in Step E was 30°C, below the normal range. This lower temperature affected the orderly arrangement and chemical bonding of the nano-titanium dioxide particles on the glass fiber surface, resulting in a less dense nanocomposite layer structure. This resulted in a compressive strength of 4.10 MPa and a crack resistance of 2.80 kN for the aerated concrete.

[0132] Comparative Example 1 uses unmodified glass fiber, which does not form a nanocomposite layer and cannot effectively reinforce concrete. Glass fiber is prone to creep under long-term stress and cannot effectively disperse stress, resulting in a compressive strength of only 3.20 MPa and a crack resistance of 2.20 kN.

[0133] Comparative Example 2 uses modified asbestos fiber instead of modified glass fiber. Asbestos fiber has different properties from glass fiber and is not effective in synergizing with other raw materials to enhance the performance of aerated concrete, resulting in a compressive strength of 3.00 MPa and a crack resistance of 2.00 kN.

[0134] Although modified glass fiber was used in Comparative Example 3, the amount was increased to 5 g. Excessive modified glass fiber may cause uneven dispersion in the concrete, affecting the uniformity of the overall structure, resulting in a compressive strength of 5.20 MPa and a crack resistance of 4.00 kN, both lower than those of Examples 1-3.

[0135] In summary, through the analysis of the performance test results of each embodiment and comparative example, it is fully verified that the present application can significantly improve the compressive strength and crack resistance of aerated concrete by modifying the glass fiber, as well as reasonable raw material ratio and preparation process.

[0136] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A glass fiber reinforced aerated concrete, characterized in that: The raw materials include the following components: Cement 20-30 parts; fly ash 10-20 parts; quicklime 15-25 parts; silica sand 30-40 parts; aluminum powder 0.1-0.3 parts; foaming agent 0.5-1.5 parts; foam stabilizer 0.5-1 parts; modified glass fiber 1-3 parts; water 25-35 parts; The modified glass fiber is obtained by forming an ordered nanocomposite layer on the surface of the glass fiber through molecular self-assembly of amino-grafted nano-titanium dioxide particles. Specifically, sodium lauryl sulfate, amino-grafted nano-titanium dioxide particles and aluminum triisopropoxide are mixed to obtain a reaction solution, and then the pH value of the reaction solution is adjusted to 6.5 with a dilute hydrochloric acid solution, and then the glass fiber is added, and then the reaction is stirred at a speed of 200 r / min at 40-50°C for 3-5 hours to obtain the modified glass fiber.

2. The glass fiber reinforced aerated concrete according to claim 1, characterized in that: The amino-grafted nano-titanium dioxide particles are prepared by the following steps: A. Tetrabutyl titanate was added dropwise to anhydrous ethanol and mixed under magnetic stirring to form solution A; B. Mix deionized water, anhydrous ethanol, and glacial acetic acid to form solution B. Take solution A and solution B at a volume ratio of 1:

1. Add solution B dropwise to solution A under stirring at a rate of 1 drop / second. After the addition is complete, continue stirring and react for 1-3 hours to obtain a nano-titanium dioxide sol. C. Aging, drying, and calcining the nano-titanium dioxide sol to obtain nano-titanium dioxide particles; D. Add nano-titanium dioxide particles to a toluene solution containing 3-aminopropyltrimethoxysilane at a concentration of 0.1-0.3 mol / L, and reflux the solution at 80°C for 4-6 hours. After the reaction, wash the solution with anhydrous ethanol, centrifuge, and dry the solution to obtain amino-grafted nano-titanium dioxide particles.

3. The glass fiber reinforced aerated concrete according to claim 2, characterized in that: In step A, the volume ratio of tetrabutyl titanate to anhydrous ethanol is 1:(3-5).

4. The glass fiber reinforced aerated concrete according to claim 2, characterized in that: In step B, the volume ratio of deionized water, anhydrous ethanol and glacial acetic acid is 5: (4-6):

2.

5. The glass fiber reinforced aerated concrete according to claim 2, characterized in that: In the step D, the mass ratio of the nano-titanium dioxide particles to the toluene solution containing 3-aminopropyltrimethoxysilane is 1:(3-5).

6. The glass fiber reinforced aerated concrete according to claim 5, characterized in that: In the step D, the mass ratio of the nano-titanium dioxide particles to the toluene solution containing 3-aminopropyltrimethoxysilane is 1:

4.

7. The glass fiber reinforced aerated concrete according to claim 1, characterized in that: The mass ratio of the sodium lauryl sulfate, the amino-grafted nano-titanium dioxide particles and aluminum triisopropoxide is 5:10:

3.

8. The glass fiber reinforced aerated concrete according to claim 1, characterized in that: The foaming agent is any one of hydrogen peroxide, azodicarbonamide and sodium bicarbonate.

9. The glass fiber reinforced aerated concrete according to claim 1, characterized in that: The foam stabilizer is any one of calcium stearate, sodium dodecylbenzene sulfonate and polyvinyl alcohol.

10. A method for preparing glass fiber reinforced aerated concrete according to any one of claims 1 to 9, characterized in that: The steps include: S1. Mix the modified glass fiber with water and stir at a speed of 200 r / min for 3-5 minutes to obtain a fiber suspension; S2. Add cement, fly ash, quicklime, silica sand, aluminum powder, foaming agent, and foam stabilizer into a mixer and stir for 3-5 minutes. Then add the fiber suspension and continue stirring for 10-15 minutes to obtain a uniform slurry. The stirring speed is 200 r / min. S3. The slurry is injected into a mold and foamed at a temperature of 40-50° C. for 3-5 hours. The slurry is stirred every 30 minutes during the foaming process. After the foaming is completed, the slurry is cured to obtain glass fiber reinforced aerated concrete.

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