Building solid waste-based double-curing high-strength wallboard and preparation method thereof

Abstract

Belonging to the technical field of building materials, the invention discloses a building solid waste based double curing high-strength wallboard, which comprises 45-65 parts of building solid waste, 10-20 parts of coarse river sand, 5-15 parts of granulated blast furnace slag powder, 15-25 parts of ordinary Portland cement, 1-5 parts of polyvinyl alcohol fiber, and 1-5 parts of polycarboxylic acid admixture. According to the scheme, the concrete strength can be rapidly enhanced through steam curing, and the production time is shortened through rapid demolding; carbon dioxide curing can chemically react with calcium oxide in the concrete to generate calcium carbonate with a stable structure, so that the strength of the concrete is enhanced. Through carbon dioxide curing, compressive strength is improved, and production material cost is effectively reduced; meanwhile, carbon dioxide can be effectively captured, and carbon dioxide emission is reduced.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, specifically to a high-strength wall panel based on solid waste for building materials and its preparation method. Background Technology

[0002] With the development of urbanization, construction waste has gradually become the largest type of solid waste generated in people's production and daily life, with an annual output of over 2 billion tons nationwide. The resource utilization of construction waste has become an urgent research task for society.

[0003] Traditional construction waste recycling mainly focuses on producing solid bricks and paving bricks, which have low added value. Recycling construction waste into precast wall panels, however, yields higher added value and can be widely used in various types of construction.

[0004] Therefore, providing a high-strength wall panel based on building solid waste with higher strength and the ability to effectively capture carbon dioxide, and its preparation method, is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a high-strength wall panel based on building solid waste with dual curing and its preparation method.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A high-strength wall panel based on building solid waste with dual curing properties, comprising the following raw materials in parts by weight: 45-65 parts of construction solid waste, 10-20 parts of coarse river sand, 5-15 parts of granulated blast furnace slag powder, 15-25 parts of ordinary silicate cement, 1-5 parts of polyvinyl alcohol fiber, and 1-5 parts of polycarboxylate admixture (i.e., polycarboxylate superplasticizer).

[0008] Furthermore, the construction solid waste consists of 35-45 parts of construction solid waste with 5mm-25mm particles and 10-20 parts of construction solid waste with 1mm-5mm particles.

[0009] Furthermore, the specific surface area of ​​the granulated blast furnace slag powder is not less than 450 m² / kg.

[0010] Furthermore, the granulated blast furnace slag powder is a material obtained by grinding steel slag from a steelmaking plant.

[0011] This invention also provides a method for preparing the above-mentioned high-strength wall panel based on building solid waste with dual curing, comprising the following steps: (1) Mixing: Weigh each raw material according to the above weight proportions, then mix each raw material with water and stir evenly, while controlling its slump to 170mm-180mm to obtain the mixture; (2) Fabric forming: Place the tied double-layer bidirectional steel mesh into the steel mold, then pour in the mixture, and form it by vibration on a vibrating table and manual tamping, and then finish the surface; (3) Steam curing: The steel mold is transported into the curing box, left to stand, and then steam is introduced to raise the temperature and keep it warm before cooling it down to within 10°C of the external environment temperature to complete the steam curing. (4) Demolding: After steam curing is completed, the wall panels are removed from the curing box and the mold is removed; (5) Carbon dioxide curing: The wall panel is placed in the curing box and carbon dioxide is introduced for curing. After curing, a high-strength wall panel with double curing based on building solid waste is obtained.

[0012] Furthermore, the settling time in step (3) is 5-7 hours; the heating and heat preservation method is to heat from room temperature to 80°C at a rate of 10-20°C / h and then maintain the temperature for 6 hours; the cooling method is to cool down at a rate of 10-15°C / h.

[0013] Furthermore, in step (5), the carbon dioxide introduction rate is 0.1-0.5 m³ / min, the carbon dioxide volume concentration is 10-20%, and the carbon dioxide curing time is 2 h.

[0014] The beneficial effects of adopting the above-mentioned further solutions are as follows: by using carbon dioxide curing technology, excess calcium oxide in concrete reacts with carbon dioxide to generate structurally stable calcium carbonate, which can improve the strength of concrete while absorbing carbon dioxide and reducing carbon dioxide emissions from building material production.

[0015] The beneficial effects of this invention are as follows: 1. This invention utilizes a crusher to crush the concrete components in construction waste, removes the mortar coating the stones, and screens the reduced crushed stone to produce high-purity recycled material. With the addition of granulated blast furnace slag powder, high-performance recycled materials can be produced, making full use of construction waste. At the same time, high-ductility fibers can be used to enhance the toughness of recycled concrete, increase flexural strength by 20-30%, and effectively reduce wall panel cracking.

[0016] 2. In the present invention, steam curing can rapidly enhance the strength of concrete and facilitate rapid demolding, reducing curing time; carbon dioxide curing can chemically react with calcium oxide in the concrete to generate structurally stable calcium carbonate, further enhancing the concrete strength. Compared with steam-cured concrete, carbon dioxide curing can increase compressive strength by 10-20%, effectively reducing production material costs; simultaneously, each ton of wall panel can absorb 100-200 kg of carbon dioxide, effectively achieving carbon capture and reducing carbon dioxide emissions from human activities. Attached Figure Description

[0017] Figure 1This is a schematic diagram of the preparation process of the wall panel of the present invention. Detailed Implementation

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Example 1 A method for preparing a high-strength wall panel based on building solid waste with dual curing: (1) Mixing: Weigh 40 parts of 5mm-25mm construction solid waste, 10 parts of 1mm-5mm construction solid waste, 17 parts of coarse river sand, 5 parts of granulated blast furnace slag powder (specific surface area not less than 450㎡ / kg), 25 parts of ordinary silicate cement, 1 part of polyvinyl alcohol fiber, and 2 parts of polycarboxylate additive. Then mix all raw materials with water and stir evenly, while controlling the slump to 170mm to obtain the mixture. (2) Fabric forming: Place the tied double-layer bidirectional steel mesh into the steel mold, then pour in the mixture, and form it by vibration on a vibrating table and manual tamping, and then finish the surface; (3) Steam curing: The steel mold is transported into the curing box, left to stand for 6 hours, and then steam is introduced. The temperature is raised to 80°C at a rate of 10°C / h and kept at a constant temperature for 6 hours. Then the temperature is lowered at a rate of 10°C / h until the temperature difference with the external environment is within 10°C to complete the steam curing. (4) Demolding: After steam curing is completed, the wall panels are removed from the curing box and the mold is removed; (5) Carbon dioxide curing: The wall panel is placed in the curing box and carbon dioxide is introduced at a rate of 0.5 m³ / min for 2 hours, and the volume concentration of carbon dioxide is 20%. After curing, a double-cured high-strength wall panel based on building solid waste is obtained.

[0020] Example 2 A method for preparing a high-strength wall panel based on building solid waste with dual curing: (1) Mixing: Weigh 35 parts of 5mm-25mm construction solid waste, 20 parts of 1mm-5mm construction solid waste, 10 parts of coarse river sand, 15 parts of granulated blast furnace slag powder (specific surface area not less than 450㎡ / kg), 15 parts of ordinary silicate cement, 3 parts of polyvinyl alcohol fiber, and 2 parts of polycarboxylate additive. Then mix all raw materials with water and stir evenly, while controlling the slump to 180mm to obtain the mixture. (2) Fabric forming: Place the tied double-layer bidirectional steel mesh into the steel mold, then pour in the mixture, and form it by vibration on a vibrating table and manual tamping, and then finish the surface; (3) Steam curing: The steel mold is transported into the curing box, left to stand for 5 hours, and then steam is introduced. The temperature is raised to 80°C at a rate of 20°C / h and kept constant for 6 hours. Then the temperature is lowered at a rate of 15°C / h until the temperature difference with the external environment is within 10°C to complete the steam curing. (4) Demolding: After steam curing is completed, the wall panels are removed from the curing box and the mold is removed; (5) Carbon dioxide curing: The wall panel is placed in the curing box and carbon dioxide is introduced at a rate of 0.1 m³ / min for 2 hours. The volume concentration of carbon dioxide is 10%. After curing, a double-cured high-strength wall panel based on building solid waste is obtained.

[0021] Example 3 A method for preparing a high-strength wall panel based on building solid waste with dual curing: (1) Mixing: Weigh 35 parts of 5mm-25mm construction solid waste, 15 parts of 1mm-5mm construction solid waste, 15 parts of coarse river sand, 10 parts of granulated blast furnace slag powder (specific surface area not less than 450㎡ / kg), 20 parts of ordinary silicate cement, 3 parts of polyvinyl alcohol fiber, and 2 parts of polycarboxylate additive. Then mix all raw materials with water and stir evenly, while controlling the slump to 175mm to obtain the mixture. (2) Fabric forming: Place the tied double-layer bidirectional steel mesh into the steel mold, then pour in the mixture, and form it by vibration on a vibrating table and manual tamping, and then finish the surface; (3) Steam curing: The steel mold is transported into the curing box, left to stand for 7 hours, and then steam is introduced. The temperature is raised to 80°C at a rate of 15°C / h and kept constant for 6 hours. Then the temperature is lowered at a rate of 12°C / h until the temperature difference with the external environment is within 10°C to complete the steam curing. (4) Demolding: After steam curing is completed, the wall panels are removed from the curing box and the mold is removed; (5) Carbon dioxide curing: The wall panel is placed in the curing box and carbon dioxide is introduced at a rate of 0.3 m³ / min for 2 hours. The volume concentration of carbon dioxide is 15%. After curing, the high-strength wall panel with double curing based on building solid waste is obtained.

[0022] Example 4 A method for preparing a high-strength wall panel based on building solid waste with dual curing: (1) Mixing: Weigh 40 parts of 5mm-25mm construction solid waste, 12 parts of 1mm-5mm construction solid waste, 13 parts of coarse river sand, 10 parts of granulated blast furnace slag powder (specific surface area not less than 450㎡ / kg), 20 parts of ordinary silicate cement, 3 parts of polyvinyl alcohol fiber, and 2 parts of polycarboxylate admixture. Then mix all raw materials with water and stir evenly, while controlling the slump to 175mm to obtain the mixture. (2) Fabric forming: Place the tied double-layer bidirectional steel mesh into the steel mold, then pour in the mixture, and form it by vibration on a vibrating table and manual tamping, and then finish the surface; (3) Steam curing: The steel mold is transported into the curing box, left to stand for 6 hours, and then steam is introduced. The temperature is raised to 80°C at a rate of 15°C / h and kept constant for 6 hours. Then the temperature is lowered at a rate of 12°C / h until the temperature difference with the external environment is within 10°C to complete the steam curing. (4) Demolding: After steam curing is completed, the wall panels are removed from the curing box and the mold is removed; (5) Carbon dioxide curing: The wall panel is placed in the curing box and carbon dioxide is introduced at a rate of 0.4 m³ / min for 2 hours. The volume concentration of carbon dioxide is 20%. After curing, the high-strength wall panel with double curing based on building solid waste is obtained.

[0023] Example 5 A method for preparing a high-strength wall panel based on building solid waste with dual curing: (1) Mixing: Weigh 43 parts of 5mm-25mm construction solid waste, 12 parts of 1mm-5mm construction solid waste, 15 parts of coarse river sand, 7 parts of granulated blast furnace slag powder (specific surface area not less than 450㎡ / kg), 21 parts of ordinary silicate cement, 4 parts of polyvinyl alcohol fiber, and 2 parts of polycarboxylate additive. Then mix all raw materials with water and stir evenly, while controlling the slump to 175mm to obtain the mixture. (2) Fabric forming: Place the tied double-layer bidirectional steel mesh into the steel mold, then pour in the mixture, and form it by vibration on a vibrating table and manual tamping, and then finish the surface; (3) Steam curing: The steel mold is transported into the curing box, left to stand for 6 hours, and then steam is introduced. The temperature is raised to 80°C at a rate of 15°C / h and kept constant for 6 hours. Then the temperature is lowered at a rate of 12°C / h until the temperature difference with the external environment is within 10°C to complete the steam curing. (4) Demolding: After steam curing is completed, the wall panels are removed from the curing box and the mold is removed; (5) Carbon dioxide curing: The wall panel is placed in the curing box and carbon dioxide is introduced at a rate of 0.4 m³ / min for 2 hours. The volume concentration of carbon dioxide is 20%. After curing, the high-strength wall panel with double curing based on building solid waste is obtained.

[0024] Example 6 A method for preparing a high-strength wall panel based on building solid waste with dual curing: (1) Mixing: Weigh 50 parts of 5mm-25mm construction solid waste, 10 parts of 1mm-5mm construction solid waste, 14 parts of coarse river sand, 8 parts of granulated blast furnace slag powder (specific surface area not less than 450㎡ / kg), 25 parts of ordinary silicate cement, 4 parts of polyvinyl alcohol fiber, and 3 parts of polycarboxylate additive. Then mix all raw materials with water and stir evenly, while controlling the slump to 175mm to obtain the mixture. (2) Fabric forming: Place the tied double-layer bidirectional steel mesh into the steel mold, then pour in the mixture, and form it by vibration on a vibrating table and manual tamping, and then finish the surface; (3) Steam curing: The steel mold is transported into the curing box, left to stand for 6 hours, and then steam is introduced. The temperature is raised to 80°C at a rate of 15°C / h and kept constant for 6 hours. Then the temperature is lowered at a rate of 12°C / h until the temperature difference with the external environment is within 10°C to complete the steam curing. (4) Demolding: After steam curing is completed, the wall panels are removed from the curing box and the mold is removed; (5) Carbon dioxide curing: The wall panel is placed in the curing box and carbon dioxide is introduced at a rate of 0.4 m³ / min for 2 hours. The volume concentration of carbon dioxide is 20%. After curing, the high-strength wall panel with double curing based on building solid waste is obtained.

[0025] The wall panels prepared in Examples 1-6 were subjected to performance tests, and the results are shown in Table 1. The results show that the method of the present invention can further improve the strength of the wall panels after curing.

[0026] Table 1

[0027] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A high-strength wall panel based on building solid waste with dual curing properties, characterized in that, Including the following parts by weight of raw materials: 45-65 parts of construction solid waste, 10-20 parts of coarse river sand, 5-15 parts of granulated blast furnace slag powder, 15-25 parts of ordinary silicate cement, 1-5 parts of polyvinyl alcohol fiber, and 1-5 parts of polycarboxylate additives.

2. The high-strength wall panel based on solid waste in construction according to claim 1, characterized in that, The construction solid waste consists of 35-45 parts of construction solid waste with 5mm-25mm particles and 10-20 parts of construction solid waste with 1mm-5mm particles.

3. The high-strength wall panel based on building solid waste with dual curing according to claim 1, characterized in that, The specific surface area of ​​the granulated blast furnace slag powder is not less than 450 m² / kg.

4. A method for preparing a high-strength wall panel based on building solid waste with dual curing, characterized in that, Includes the following steps: (1) Mixing: Weigh each raw material according to the weight proportions of any one of claims 1-3, then mix each raw material with water and stir evenly, while controlling its slump to be 170mm-180mm to obtain a mixture; (2) Fabric forming: Place the tied double-layer bidirectional steel mesh into the steel mold, then pour in the mixture, and form it by vibration on a vibrating table and manual tamping, and then finish the surface; (3) Steam curing: The steel mold is transported into the curing box, left to stand, and then steam is introduced to raise the temperature and keep it warm before cooling it down to within 10°C of the external environment temperature to complete the steam curing. (4) Demolding: After steam curing is completed, the wall panels are removed from the curing box and the mold is removed; (5) Carbon dioxide curing: The wall panel is placed in the curing box and carbon dioxide is introduced for curing. After curing, a high-strength wall panel with double curing based on building solid waste is obtained.

5. The method for preparing a high-strength wall panel based on building solid waste with dual curing according to claim 4, characterized in that, The settling time in step (3) is 5-7h; the heating and heat preservation method is to heat from room temperature to 80℃ at a rate of 10-20℃ / h and then keep it at a constant temperature for 6h; the cooling method is to cool down at a rate of 10-15℃ / h.

6. The method for preparing a high-strength wall panel based on building solid waste with dual curing according to claim 4, characterized in that, The carbon dioxide introduction rate in step (5) is 0.1-0.5 m³ / min, the volume concentration of the carbon dioxide is 10-20%, and the carbon dioxide curing time is 2 h.

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