Water-retaining porous brick and preparation method thereof

Abstract

The invention relates to the technical field of building materials, and particularly discloses a water-retaining porous brick and a preparation method thereof. The water-retaining porous brick provided by the invention is specifically prepared from the following components in parts by weight: 3 to 4 parts of fly ash, 1 to 1.4 parts of clay, 0.6 to 0.8 part of quick lime, 0.2 to 0.3 part of gypsum, 0.3 to 0.5 part of a water-retaining agent and 0.15 to 0.25 part of a durability agent, the water-retaining agent is obtained by mixing straw powder, aluminum hydroxide and a 0.5-1.5 wt% polyvinyl alcohol aqueous solution according to the weight ratio of (10-20): (10-20): (0.5-1.0); the durable agent is prepared by compounding nano silicon dioxide modified zeolite and phenol amine modified diatomite in a weight ratio of (10-15): (0.5-3). The water-retaining porous brick prepared by the invention is high in porosity, excellent in water-retaining property and mechanical property, and relatively high in durability.

Description

Technical Field

[0001] The present application relates to the technical field of building materials, and particularly relates to a water-retaining porous brick and a preparation method thereof. Background Art

[0002] In the current urbanization process, traditional building methods have led to surface hardening, a rapid increase in rainwater runoff, causing urban waterlogging and water resource waste. Existing building materials have limited functions in rainwater collection and utilization, lacking effective permeability and water retention capacity.

[0003] Currently, there are similar porous brick products on the market. However, although traditional porous bricks have a certain degree of water permeability, their water retention capacity, strength, and durability often cannot meet the requirements of sponge city construction. In particular, in heavy traffic areas, the structure of porous bricks is easily damaged, affecting their service life. Summary of the Invention

[0004] In order to solve the above technical problems, the present application provides a water-retaining porous brick and a preparation method thereof.

[0005] In the first aspect, the present application provides a water-retaining porous brick, which specifically includes the following components in parts by weight: 3 - 4 parts of fly ash, 1 - 1.4 parts of clay, 0.6 - 0.8 parts of quicklime, 0.2 - 0.3 parts of gypsum, 0.3 - 0.5 parts of water retention agent, and 0.15 - 0.25 parts of durability agent; The water retention agent is obtained by mixing straw powder, aluminum hydroxide, and 0.5 - 1.5 wt% polyvinyl alcohol aqueous solution in a weight ratio of 10 - 20:10 - 20:0.5 - 1.0; The durability agent is obtained by compounding nano-silica modified zeolite and phenolamine modified diatomite in a weight ratio of 10 - 15:0.5 - 3.

[0006] The present application obtains a water retention agent by mixing straw powder, aluminum hydroxide, and 0.5 - 1.5 wt% polyvinyl alcohol aqueous solution in a specific ratio, and obtains a durability agent by compounding nano-silica modified zeolite and phenolamine modified diatomite in a weight ratio of 10 - 15:0.5 - 3. The prepared water-retaining porous brick has a high porosity, excellent water retention and mechanical properties, and high durability.

[0007] Among the raw material components of the water-retaining porous brick, fly ash and clay, as the main raw materials, provide the basic strength and structural framework of the brick. They have rich mineral components, which help to enhance the strength and stability of the brick. Quicklime and gypsum act as coagulants in the preparation process; they can react with water to form a hard crystal structure, thereby improving the compressive strength and durability of the brick.

[0008] The water retaining agent plays a crucial role in the preparation of water retaining porous bricks. It can form a uniform pore structure inside the bricks, endowing them with strong water absorption capacity and surface tension, which is beneficial for the water retention of the porous bricks. The addition of straw powder provides a natural and renewable pore-forming material for the bricks. During the brick blank forming and firing processes, the straw powder will burn or decompose, leaving tiny pores, which contribute to enhancing the water absorption and water retention capabilities of the bricks. The introduction of aluminum hydroxide further strengthens the pore structure of the bricks. Aluminum hydroxide will decompose at high temperatures, releasing water and leaving voids, and these voids communicate with the pores left by the straw powder to form a more uniform pore network. Polyvinyl alcohol is a polymer with good adhesiveness and film-forming properties. During the brick blank forming process, it helps to promote the balanced micropore-macropore distribution of straw powder and aluminum hydroxide, forming a stable pore structure of the brick blank and further improving the water retention capacity.

[0009] However, the multi-porous structure of the brick blank tends to result in poor mechanical and durability properties. To solve this problem, in this application, by adding a durable agent, nano-silica modified zeolite has an extremely high specific surface area and adsorption capacity, which can effectively absorb and store water, providing a long-lasting water retention effect for the porous bricks; at the same time, it can effectively absorb and fix the free water and harmful ions in the bricks, which not only reduces the destructive effect on the brick structure but also prevents the erosion of harmful ions on the brick materials, thereby extending the service life of the porous bricks. Phenolamine modified diatomite has excellent water absorption and water retention properties. The hydrophilic groups on its surface can better combine with the surrounding water molecules to form a stable water storage layer; during the firing process, the unique pore structure of diatomite is retained, which is not only beneficial for the storage and release of water but also can increase the compressive strength of the bricks to a certain extent. When these two modified materials are compounded and mixed and then fired, they form a strengthened network structure inside the porous bricks; this structure, through the filling of nano-silica modified zeolite and the pore support of phenolamine modified diatomite, jointly improves the compressive strength of the porous bricks; at the same time, diatomite itself has excellent physical and chemical stability, and phenolamine modification enhances its compatibility and weather resistance with the surrounding environment; this enables phenolamine modified diatomite to form a protective barrier on the surface of the bricks to resist the erosion of adverse factors such as water, oxygen, and ultraviolet rays in the external environment on the bricks. In addition, through reasonable compounding and mixing of nano-silica modified zeolite and phenolamine modified diatomite, a stable chemical bonding and network structure can also be formed during the firing process. This structure not only improves the overall strength of the porous bricks but also enhances their ability to resist external factors such as temperature changes and mechanical wear.

[0010] Preferably, the water-retaining porous brick specifically comprises the following components in parts by weight: 3.2-3.8 parts of fly ash, 1.1-1.3 parts of clay, 0.65-0.75 parts of quicklime, 0.22-0.28 parts of gypsum, 0.35-0.45 parts of water-retaining agent, and 0.17-0.22 parts of durability agent.

[0011] Preferably, the water-retaining agent is obtained by mixing straw powder, aluminum hydroxide, and 0.5-1.5 wt% aqueous polyvinyl alcohol solution in a weight ratio of 10-14:16-20:0.7-0.9.

[0012] Preferably, the viscosity of the polyvinyl alcohol is 40-48 mPa·s.

[0013] Preferably, the durability agent is obtained by compounding nano-silica modified zeolite and phenolamine modified diatomite in a weight ratio of 11-14:0.7-2.

[0014] Preferably, the preparation method of the nano-silica modified zeolite is as follows: Disperse zeolite in an ethanol-water mixed solvent with a volume ratio of 0.5-1.5:0.5-1.5, add tetraethyl orthosilicate and ammonia water, react at 60-80 °C for 5-10 h, centrifuge, wash, and dry to obtain nano-silica modified zeolite; the weight ratio of the ethanol-water mixed solvent, zeolite, tetraethyl orthosilicate, and ammonia water is 100:20-30:2-6:0.2-0.8.

[0015] Preferably, the preparation method of the phenolamine modified diatomite is as follows: Immerse diatomite in a catechol-tetraethylenepentamine mixed aqueous solution, and adjust its pH to 9.0-10.5; stir and react at room temperature for 6-12 h, centrifuge, and dry to obtain phenolamine modified diatomite; the concentration of catechol in the catechol-tetraethylenepentamine mixed aqueous solution is 1-5 mmol / L, and the concentration of tetraethylenepentamine is 25-35 mmol / L; the performance parameters of the diatomite are: 5-20 μm, specific surface area 20-40 m 2 / g.

[0016] Preferably, the density of the fly ash is 2200-2300 kg / m 3 , water demand ratio 92-96%, fineness 15-17%, loss on ignition 2.0-2.3%.

[0017] In the second aspect, the present application provides a method for preparing the above-mentioned water-retaining porous bricks, which specifically includes the following steps in sequence: according to Table 1, weigh the corresponding weight of each raw material component respectively; mix the fly ash, clay, quicklime, gypsum, water-retaining agent and durability agent evenly; add water with a moisture content of 11-18% to the dry powder material, stir it thoroughly until there is no dry powder to obtain a slurry, press the slurry into bricks with a brick-making machine, dry it in the shade at room temperature for 6-12 hours, and then burn it to obtain a water-retaining porous brick.

[0018] Preferably, the firing process parameters are: preheating the air-dried bricks from room temperature to 150-250°C at a heating rate of 2-15°C / min, and maintaining for 30-60min; then heating to 850-1050°C at a heating rate of 5-20°C / min, and roasting for 15-30min; then cooling to 400-550°C at a cooling rate of 5-10°C / min, and stabilizing for 10-20min; finally cooling to room temperature at a cooling rate of 2-20°C / min, and then naturally curing for 24h to obtain water-retaining porous bricks.

[0019] In summary, the technical solution of this application has the following effects: The present application adopts straw powder, aluminum hydroxide, and 0.5-1.5wt% polyvinyl alcohol aqueous solution to mix in a specific ratio to obtain a water-retaining agent, and adopts nano-silicon dioxide-modified zeolite and phenolamine-modified diatomaceous earth to compound to obtain a durability agent. The prepared water-retaining porous brick has a high porosity, excellent water retention and mechanical properties, and the porous brick has high durability. DETAILED DESCRIPTION

[0020] The present application is further described in detail below in conjunction with examples, comparative examples and performance testing experiments. These examples should not be construed as limiting the scope of protection claimed in the present application.

[0021] The performance parameters or sources of the raw materials used in this application are as follows: straw powder is crushed to a particle size of ≤400 mesh; polyvinyl alcohol (article number V30211, viscosity 40-48mPa.s), (article number V30210, viscosity 54-66mPa.s), purchased from Shanghai Yuanye Biotechnology Co., Ltd.; zeolite is mordenite, pore size 0.3-1nm, specific surface area 380m 2 / g, particle size 200-400 mesh; diatomite particle size 5-20μm, specific surface area 30m 2 / g; the density of fly ash is 2280kg / m 3 , water requirement ratio 94%, fineness 16%, loss on ignition 2.1%; the clay was purchased from Shijiazhuang Allen Mineral Products Co., Ltd. Example

[0022] Examples 1-5 Examples 1-5 respectively provide a water-retaining porous brick and a preparation method thereof.

[0023] The differences among the above examples are as follows: the dosages of each component in the water-retaining porous brick are different, as specifically shown in Table 1.

[0024] The preparation method of the water-retaining porous brick in the above examples is specifically as follows.

[0025] Water-retaining agent: obtained by mixing straw powder, aluminum hydroxide, and 1wt% aqueous polyvinyl alcohol solution with a weight ratio of 12:18:0.8, and the viscosity of polyvinyl alcohol is 40-48 mPa·s.

[0026] The preparation method of nano-silica modified zeolite is as follows: disperse 250 g of zeolite in 1000 g of ethanol-water mixed solvent with a volume ratio of 1:1, add 40 g of tetraethyl orthosilicate and 5 g of ammonia water, react at 70 °C for 7 h, centrifuge, wash with the reaction solvent, and dry at 104 °C to obtain nano-silica modified zeolite; the weight ratio of ethanol-water mixed solvent, zeolite, tetraethyl orthosilicate, and ammonia water is 100:25:4:0.5.

[0027] The preparation method of phenolic amine modified diatomite is as follows: immerse diatomite in a catechol-tetraethylenepentamine mixed aqueous solution, adjust its pH to 10.0 with sodium hydroxide aqueous solution; stir and react at room temperature for 9 h, centrifuge and dry at 104 °C to obtain phenolic amine modified diatomite; the concentration of catechol in the catechol-tetraethylenepentamine mixed aqueous solution is 2 mmol / L, and the concentration of tetraethylenepentamine is 30 mmol / L.

[0028] Durability agent: obtained by compounding nano-silica modified zeolite and phenolic amine modified diatomite with a weight ratio of 12:1.

[0029] According to Table 1, weigh the corresponding weights of each raw material component respectively; mix fly ash, clay, quicklime, gypsum, water-retaining agent, and durability agent evenly; add water (water content 14%) to the dry powder material and stir well until there is no dry powder state to obtain a slurry.

[0030] Press the slurry into bricks with a brick-making machine, with a pressing force of 1 T. After air-drying at room temperature for 8 h, then preheat the bricks from room temperature to 200 °C at a heating rate of 8 °C / min and maintain for 45 min; then heat to 1000 °C at a heating rate of 10 °C / min and roast for 20 min, then cool to 480 °C at a cooling rate of 8 °C / min and stabilize for 15 min, and finally cool to room temperature at a rate of 10 °C / min, and then cure naturally for 24 h to obtain water-retaining porous bricks with a specification of 150 mm × 80 mm × 50 mm.

[0031] Table 1 Dosages of each component in the water-retaining porous bricks of Examples 1-5 Examples 6-9 Examples 6-9 respectively provide a water-retaining porous brick and a preparation method thereof.

[0032] The differences between the above examples and Example 3 are specifically as follows: the compositions of the water-retaining agents are different, as shown below.

[0033] In Example 6: The water-retaining agent is obtained by mixing straw powder, aluminum hydroxide, and 1 wt% polyvinyl alcohol aqueous solution with a weight ratio of 12:18:0.8, and the viscosity of the polyvinyl alcohol is 54-66 mPa·s.

[0034] In Example 7: The water-retaining agent is obtained by mixing straw powder, aluminum hydroxide, and 1 wt% polyvinyl alcohol aqueous solution with a weight ratio of 18:12:0.8.

[0035] In Example 8: The water-retaining agent is obtained by mixing straw powder, aluminum hydroxide, and 1 wt% polyvinyl alcohol aqueous solution with a weight ratio of 10:20:0.7.

[0036] In Example 9: The water-retaining agent is obtained by mixing straw powder, aluminum hydroxide, and 1 wt% polyvinyl alcohol aqueous solution with a weight ratio of 14:16:0.9.

[0037] The other process parameters in the above examples are the same as those in Example 3.

[0038] Examples 10-13 Examples 10-13 respectively provide a water-retaining porous brick and a preparation method thereof.

[0039] The differences between the above examples and Example 3 are specifically as follows: the compositions of the durability agents are different, as shown below.

[0040] In Example 10: The preparation method of nano-silica modified zeolite in the durability agent is as follows: Disperse 250 g of zeolite in an ethanol-water mixed solvent (ethanol-water mixed solvent with a volume ratio of 1:1) containing 2 wt% KH-550, reflux at 80 °C for 2 h; add 40 g of nano-SiO2, adjust the pH to 4-5 to promote the condensation reaction, react at 60 °C for 4 h, centrifuge, and dry at 104 °C to obtain nano-silica modified zeolite.

[0041] In Example 11: The preparation method of phenolic amine modified diatomite in the durability agent is as follows: Immerse diatomite in a catechol-tetraethylenepentamine mixed aqueous solution, and adjust its pH to 10.0 with an aqueous sodium hydroxide solution; stir and react at room temperature for 9 h, centrifuge, and dry at 104 °C to obtain phenolic amine modified diatomite; the concentration of catechol in the catechol-tetraethylenepentamine mixed aqueous solution is 20 mmol / L, and the concentration of tetraethylenepentamine is 5 mmol / L.

[0042] In Example 12: The durability agent is obtained by compounding nano-silica modified zeolite and phenolic amine modified diatomite with a weight ratio of 15:0.5.

[0043] In Example 13: The durability agent is obtained by compounding nano-silica modified zeolite and phenolic amine modified diatomite with a weight ratio of 10:3.

[0044] In the above examples, other process parameters are the same as those in Example 3.

[0045] Comparative Example Comparative Examples 1-4 Comparative Examples 1-4 respectively provide a water-retaining porous brick and its preparation method.

[0046] The differences between the above comparative examples and Example 3 are specifically as follows.

[0047] In Comparative Example 1: The water-retaining agent is obtained by mixing straw powder, calcium carbonate, and 1wt% polyvinyl alcohol aqueous solution with a weight ratio of 12:18:0.8, and the viscosity of polyvinyl alcohol is 54-66 mPa·s.

[0048] In Comparative Example 2: The water-retaining agent is obtained by mixing straw powder, aluminum hydroxide, and 1wt% polyvinyl alcohol aqueous solution with a weight ratio of 20:2:0.8, and the viscosity of polyvinyl alcohol is 54-66 mPa·s.

[0049] In Comparative Example 3: The durability agent is obtained by compounding nano-silica modified zeolite and diatomite (not modified) with a weight ratio of 12:1.

[0050] In Comparative Example 4: The durability agent is obtained by compounding nano-silica modified zeolite and phenolic amine modified diatomite with a weight ratio of 1:12.

[0051] In the above comparative examples, other process parameters are the same as those in Example 3.

[0052] Performance Detection Test Porosity: Measured and calculated by the Archimedes drainage method.

[0053] Water retention rate: Referring to the test method of JC / T 945-2005, after the brick body is immersed in water for 24 hours to be saturated with water absorption, the mass ratio of the water retained under standard conditions.

[0054] Compressive strength: Referring to the test method of GB / T 4111-2013, the compressive strength is detected.

[0055] Durability: Referring to the test method of GB / T 4111-2013, after 25 freeze-thaw cycles, the water absorption loss rate and compressive strength loss rate are measured.

[0056] Detection results: As shown in Table 2.

[0057] Table 2 Performance test results of water-retaining perforated bricks in examples and comparative examples From the test results in the above table, it can be seen that by using the technical solution provided by this application, the prepared water-retaining perforated brick has a high porosity, excellent water retention and mechanical properties, and high durability of the perforated brick.

[0058] By comparing the test results of Examples 1-5, it can be seen that the dosage of each raw material component has an instructive influence on the performance of the perforated brick. By screening the dosage of each raw material component within a specific range, this application has obtained water-retaining perforated bricks with excellent performance.

[0059] By comparing the test results of Example 3, Examples 6-9, and Comparative Examples 1-2, it can be seen that by selecting a water-retaining agent obtained by mixing straw powder, aluminum hydroxide, and a 0.5-1.5 wt% aqueous solution of polyvinyl alcohol in a weight ratio of 10-20:10-20:0.5-1.0, the performance of the water-retaining perforated brick is further improved.

[0060] By comparing the test results of Example 3, Examples 10-13, and Comparative Examples 3-4, it can be seen that by selecting a durability agent obtained by compounding nano-silica modified zeolite and phenolamine modified diatomaceous earth in a weight ratio of 10-15:0.5-3, the performance of the water-retaining perforated brick is further improved.

[0061] Although the present invention has been described in detail above with general descriptions and specific embodiments, based on the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection required by the present invention.

Claims

1. A water-retaining porous brick, characterized in that, Specifically, it includes the following components in parts by weight: 3 - 4 parts of fly ash, 1 - 1.4 parts of clay, 0.6 - 0.8 parts of quicklime, 0.2 - 0.3 parts of gypsum, 0.3 - 0.5 parts of water retaining agent, and 0.15 - 0.25 parts of durability agent; The water retaining agent is obtained by mixing straw powder, aluminum hydroxide, and 0.5 - 1.5 wt% polyvinyl alcohol aqueous solution in a weight ratio of 10 - 20:10 - 20:0.5 - 1.0; The durability agent consists of a weight ratio of 10 - 15: 0.5 - 3 of nano - silica - modified zeolite and phenol - amine - modified diatomite are compounded.

2. The water-retaining porous brick according to claim 1, characterized in that, Specifically, it includes the following components in parts by weight: 3.2 - 3.8 parts of fly ash, 1.1 - 1.3 parts of clay, 0.65 - 0.75 parts of quicklime, 0.22 - 0.28 parts of gypsum, 0.35 - 0.45 parts of water retaining agent, and 0.17 - 0.22 parts of durability agent.

3. The water-retaining porous brick according to claim 1, wherein The water retaining agent is obtained by mixing straw powder, aluminum hydroxide, and 0.5 - 1.5 wt% polyvinyl alcohol aqueous solution in a weight ratio of 10 - 14:16 - 20:0.7 - 0.9; 4. The water-retaining porous brick according to claim 1, wherein The viscosity of the polyvinyl alcohol is 40 - 48 mPa·s.

5. The water-retaining porous brick according to claim 1, characterized in that, The durability agent is obtained by compounding nano - silica - modified zeolite and phenol - amine - modified diatomite in a weight ratio of 11 - 14:0.7 - 2.

6. The water-retaining porous brick according to claim 1, characterized in that, The preparation method of the nano - silica - modified zeolite is as follows: Disperse zeolite in an ethanol - water mixed solvent with a volume ratio of 0.5 - 1.5:0.5 - 1.5, add tetraethyl orthosilicate and ammonia water, react at 60 - 80 °C for 5 - 10 h, centrifuge, wash, and dry to obtain nano - silica - modified zeolite; the weight ratio of the ethanol - water mixed solvent, zeolite, tetraethyl orthosilicate, and ammonia water is 100:20 - 30:2 - 6:0.2 - 0.

8.

7. The water-retaining porous brick according to claim 1, wherein The preparation method of the phenol - amine - modified diatomite is as follows: Immerse diatomite in an aqueous solution of catechol - tetraethylenepentamine, adjust its pH to 9.0 - 10.5; stir and react at room temperature for 6 - 12 h, centrifuge and dry to obtain phenol - amine - modified diatomite; The concentration of catechol in the catechol-tetraethylenepentamine mixed aqueous solution is 1-5 mmol / L, and the concentration of tetraethylenepentamine is 25-35 mmol / L; the performance parameters of the diatomite are: 5-20 μm, specific surface area 20-40 m 2 / g.

8. The water-retaining porous brick according to claim 1, characterized in that, The density of the fly ash is 2200-2300 kg / m 3 , the water demand ratio is 92-96%, the fineness is 15-17%, and the loss on ignition is 2.0-2.3%.

9. The preparation method of the water-retaining porous brick according to any one of claims 1-8, characterized in that, Specifically, it includes the following steps in sequence: Weigh the corresponding raw material components according to Table 1; mix fly ash, clay, quicklime, gypsum, water retaining agent, and durability agent evenly; add water with a moisture content of 11 - 18% to the dry powder material, stir thoroughly until there is no dry powder state to obtain a slurry, press the slurry into bricks with a brick - making machine, air - dry at room temperature for 6 - 12 h, and then obtain water - retaining porous bricks through firing.

10. The preparation method of the water-retaining porous brick according to claim 9, characterized in that, The technological parameters of the firing are as follows: Preheat the air - dried bricks from room temperature to 150 - 250 °C at a heating rate of 2 - 15 °C / min and maintain for 30 - 60 min; then heat up to 850 - 1050 °C at a heating rate of 5 - 20 °C / min and roast for 15 - 30 min; then cool down to 400 - 550 °C at a cooling rate of 5 - 10 °C / min and stabilize for 10 - 20 min; finally, cool down to room temperature at a cooling rate of 2 - 20 °C / min and then cure naturally for 24 h to obtain water - retaining porous bricks.

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