Unfired antique black brick and preparation process thereof

Abstract

The baking-free antique black brick is prepared from the following raw materials in parts by weight: 40 to 50 parts of waste concrete recycled aggregate, 20 to 30 parts of coal gangue powder, 15 to 20 parts of 42.5-grade ordinary Portland cement, 3 to 5 parts of water glass, 0.5 to 1 part of calcium lignosulphonate, 0.1 to 0.3 part of lithium carbonate, 0.5 to 1.5 parts of iron oxide black and 0.1 to 0.3 part of carbon black. A large amount of waste concrete recycled aggregate and coal gangue powder are used, construction waste emission and natural resource exploitation are reduced, high-temperature firing energy consumption and pollutant emission are avoided through the non-firing process, the green and environment-friendly concept is met, and the cost benefits are that waste raw materials are utilized, the raw material cost is reduced, and the equipment investment and energy consumption are reduced through the non-firing process; the preparation process is simple, easy to operate and high in production efficiency, and the economic benefits and market competitiveness of enterprises are improved.

Description

Technical Field

[0001] The invention relates to the technical field of building materials, in particular to an unfired antique blue brick and a preparation process thereof. Background Art

[0002] Antique blue bricks are widely used in the fields of ancient building restoration, garden landscape construction and characteristic building decoration due to their simple and elegant appearance. Traditional blue bricks need to be fired at high temperature for a long time, which consumes a lot of energy and causes great pollution. In addition, the bricks are prone to deformation and cracking during firing, and the yield rate is difficult to guarantee.

[0003] With the popularization of environmental protection concepts and the growing demand for sustainable resource utilization, unfired brick technology has emerged. However, some existing unfired antique blue bricks are not strong enough and are easily damaged during transportation, construction or long-term use; some have uneven appearance and color, making it difficult to perfectly restore the ancient texture of traditional blue bricks; others have poor frost resistance, acid and alkali resistance, and poor durability in complex climates and environments, which limits the promotion and application of unfired antique blue bricks. It is urgent to develop an unfired antique blue brick with excellent performance that can meet market demand and its preparation process. Summary of the invention

[0004] In response to the problems in the related art, the present invention aims to provide an unfired antique blue brick and its preparation process, so as to solve the problems of high energy consumption and great pollution in traditional fired blue bricks, as well as the strength, appearance and durability of existing unfired blue bricks, and to produce an unfired antique blue brick with high strength, realistic appearance and good durability.

[0005] Raw material formula:

[0006] Basic aggregate: 40-50 parts of recycled aggregate from waste concrete and 20-30 parts of coal gangue powder are used. The recycled aggregate from waste concrete is crushed and sieved to a particle size of 0.1-5mm, which can effectively utilize construction waste and reduce costs; the coal gangue powder is ground to a specific surface area of ​​300-400m 2 / kg, providing structural support for the green bricks.

[0007] Binder: Use 15-20 parts of 42.5 grade ordinary Portland cement and 3-5 parts of water glass. Cement is the main bonding component, and water glass can enhance the bonding effect and improve the early strength.

[0008] Additives: Add 0.5-1 parts of calcium lignin sulfonate as a water reducer to reduce water consumption and improve the fluidity and density of the mixture; 0.1-0.3 parts of lithium carbonate as a coagulant to accelerate the cement hydration reaction; and 0.5-1.5 parts of black iron oxide and 0.1-0.3 parts of carbon black are used to adjust the color of the blue bricks to give them an ancient blue-black color.

[0009] Preparation process:

[0010] Raw material pretreatment: The waste concrete recycled aggregate and coal gangue powder are dried separately to remove moisture and control the moisture content below 1% to ensure the uniformity and stability of the raw material mixing.

[0011] Mixing: According to the formula ratio, first put the waste concrete recycled aggregate and coal gangue powder into the forced mixer, dry mix for 3-5 minutes to make it initially mixed evenly. Then add cement, calcium lignin sulfonate, lithium carbonate, black iron oxide, and carbon black, and continue dry mixing for 2-3 minutes. Then slowly add water glass and appropriate amount of water, control the water-cement ratio at 0.3-0.35, and wet mix for 8-10 minutes to ensure that all ingredients are fully integrated to form a uniform mixture with good plasticity.

[0012] Molding: The stirred mixture is quickly loaded into the custom antique blue brick mold. The mold is designed according to the size of traditional blue bricks, and the size error is controlled within ±1mm. A hydraulic molding machine is used to maintain pressure at 15-20MPa for 3-5 minutes to shape the brick blank, ensuring that the brick blank has accurate size, smooth surface and dense structure.

[0013] Curing: The formed bricks are first placed in an environment with a temperature of 20±2℃ and a relative humidity of more than 90% for 1-2 days for preliminary hardening. Then they are transferred to a steam curing room and cured for 6-8 hours at a temperature of 80-90℃ and a steam pressure of 0.1-0.15MPa to accelerate the cement hydration reaction and improve the strength of the bricks. After the curing is completed, they are naturally cooled to room temperature.

[0014] Beneficial Effects of the Invention

[0015] Environmental protection and energy saving: A large amount of recycled aggregates from waste concrete and coal gangue powder are used to reduce the emission of construction waste and the exploitation of natural resources. The firing-free process avoids high-temperature firing energy consumption and pollutant emissions, which is in line with the concept of green environmental protection.

[0016] Excellent performance: After optimizing the formula and process, the compression strength of the unfired antique blue bricks can reach more than 30MPa, and the flexural strength can reach more than 5MPa, which meets the strength requirements of building use. Through precise control of color additives, the blue bricks have uniform color, simple and natural, and highly restore the appearance of traditional blue bricks. After steam curing, the brick structure is dense, the number of freeze-thaw cycles exceeds 25, the acid and alkali resistance is good, and the durability is greatly improved.

[0017] Cost-effectiveness: Utilize waste raw materials to reduce raw material costs. The firing-free process reduces equipment investment and energy consumption. The preparation process is simple and easy to operate, with high production efficiency, which improves the company's economic benefits and market competitiveness. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0019] Figure 1 The present invention is a process flow chart of a manufacturing process of an unfired antique blue brick; DETAILED DESCRIPTION

[0020] According to an embodiment of the present invention, a non-fired antique blue brick and a preparation process thereof are provided.

[0021] A non-fired antique blue brick is made of the following raw materials in parts by weight: 40-50 parts of recycled aggregate from waste concrete, 20-30 parts of coal gangue powder, 15-20 parts of 42.5-grade ordinary Portland cement, 3-5 parts of water glass, 0.5-1 part of calcium lignin sulfonate, 0.1-0.3 parts of lithium carbonate, 0.5-1.5 parts of black iron oxide, and 0.1-0.3 parts of carbon black. The particle size of the recycled aggregate from waste concrete is controlled at 0.1-5 mm, and the specific surface area of ​​the coal gangue powder is 300-400 m 2 / kg.

[0022] The preparation process of the unfired antique blue brick is characterized by comprising the following steps:

[0023] Raw material pretreatment: The waste concrete recycled aggregate and coal gangue powder are dried separately to control their moisture content below 1%;

[0024] Mixing: According to the formula ratio, first put the waste concrete recycled aggregate and coal gangue powder into the forced mixer for dry mixing for 3-5 minutes, then add cement, calcium lignin sulfonate, lithium carbonate, black iron oxide, and carbon black and continue dry mixing for 2-3 minutes, then slowly add water glass and water, control the water-cement ratio at 0.3-0.35, and wet mix for 8-10 minutes to form a mixture;

[0025] Molding: put the mixture into the antique blue brick mold, and use a hydraulic molding machine to maintain pressure at 15-20MPa for 3-5 minutes to shape the brick;

[0026] Curing: The formed bricks are first placed in an environment with a temperature of 20±2℃ and a relative humidity of more than 90% for 1-2 days, then transferred to a steam curing room, cured for 6-8 hours at a temperature of 80-90℃ and a steam pressure of 0.1-0.15MPa, and naturally cooled to room temperature.

[0027] Embodiment 1:

[0028] Raw material preparation: weigh 42 parts of waste concrete recycled aggregate, 25 parts of coal gangue powder, 18 parts of 42.5 grade ordinary Portland cement, 4 parts of water glass, 0.8 parts of calcium lignin sulfonate, 0.2 parts of lithium carbonate, 1 part of black iron oxide, and 0.2 parts of carbon black. The waste concrete recycled aggregate is crushed and sieved to a particle size of 0.1-5mm, and the coal gangue powder is ground to a specific surface area of ​​350m 2 / kg, the raw materials were dried to a moisture content of 0.8%.

[0029] Mixing: Add waste concrete recycled aggregate and coal gangue powder into a forced mixer and dry mix for 4 minutes. Add cement, calcium lignin sulfonate, lithium carbonate, black iron oxide, and carbon black, and continue dry mixing for 2.5 minutes. Slowly add water glass and water at a water-cement ratio of 0.32, wet mix for 9 minutes to obtain a uniform mixture.

[0030] Molding: Load the mixture into the antique blue brick mold, maintain the pressure at 18MPa on the hydraulic molding machine for 4 minutes, and the bricks are formed with a dimensional error controlled within ±0.8mm.

[0031] Curing: The bricks were kept at 20℃ and 92% relative humidity for 1.5 days, then transferred to the steam curing room, cured at 85℃ and 0.12MPa steam pressure for 7 hours, and cooled naturally to room temperature. After testing, the compressive strength of the bricks was 32MPa, the flexural strength was 5.2MPa, the appearance color was uniform, and the freeze-thaw resistance was 28 times.

[0032] Embodiment 2:

[0033] Raw material preparation: weigh 45 parts of recycled aggregate from waste concrete, 23 parts of coal gangue powder, 16 parts of 42.5 grade ordinary Portland cement, 3.5 parts of water glass, 0.6 parts of calcium lignin sulfonate, 0.15 parts of lithium carbonate, 1.2 parts of black iron oxide, and 0.25 parts of carbon black. The particle size of recycled aggregate from waste concrete is 0.1-5mm, and the specific surface area of ​​coal gangue powder is 320m 2 / kg, raw material moisture content 0.6%.

[0034] Mixing: First dry mix the aggregate for 3.5 minutes, add other powders and dry mix for 2 minutes, then add water according to the water-cement ratio of 0.33 and wet mix for 8.5 minutes.

[0035] Molding: Molding is carried out at a pressure of 16MPa for 3.5 minutes, and the brick size error is ±0.9mm.

[0036] Curing: 1 day of static curing, steam curing temperature 82℃, pressure 0.11MPa, curing for 6.5 hours. The compressive strength of the bricks was 31MPa, the flexural strength was 5.1MPa, the appearance was simple, and the freeze-thaw resistance was 26 times.

[0037] It can be seen from the above embodiments that the unfired antique blue brick and the preparation process thereof of the present invention can stably produce unfired antique blue bricks with excellent performance and realistic appearance, meeting the market demand for high-quality blue bricks.

[0038] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A kind of unfired antique blue brick, characterized in that: The invention is made of the following raw materials in parts by weight: 40-50 parts of recycled aggregate from waste concrete, 20-30 parts of coal gangue powder, 15-20 parts of 42.5-grade ordinary Portland cement, 3-5 parts of water glass, 0.5-1 part of calcium lignin sulfonate, 0.1-0.3 part of lithium carbonate, 0.5-1.5 parts of black iron oxide and 0.1-0.3 part of carbon black.

2. A process for producing unfired antique blue bricks, characterized in that: The particle size of the recycled aggregate from waste concrete is controlled at 0.1-5 mm, and the specific surface area of ​​the coal gangue powder is 300-400 m 2 / kg.

3. A process for preparing the unfired antique blue brick according to any one of claims 1 to 2, characterized in that: The following steps are involved: Step 1: Raw material pretreatment; Step 2: Mix and stir; Step 3: Molding; Step 4: Maintenance.

4. The process for preparing the unfired antique blue brick according to claim 3, characterized in that: The raw material pretreatment in step 1 is as follows: the waste concrete recycled aggregate and coal gangue powder are dried separately to control the water content thereof to be below 1%.

5. The process for preparing the unfired antique blue brick according to claim 3, characterized in that: The mixing and stirring in the step 2 is as follows: according to the formula ratio, firstly put the waste concrete recycled aggregate and coal gangue powder into a forced mixer and dry mix for 3-5 minutes, then add cement, calcium lignin sulfonate, lithium carbonate, black iron oxide and carbon black and continue dry mixing for 2-3 minutes, then slowly add water glass and water, control the water-cement ratio at 0.3-0.35, wet mix for 8-10 minutes to form a mixture.

6. The process for preparing the unfired antique blue brick according to claim 3, characterized in that: The forming in step three is as follows: the mixture is loaded into an antique blue brick mold, and a hydraulic molding machine is used to maintain the pressure at 15-20 MPa for 3-5 minutes to form the brick.

7. The process for preparing the unfired antique blue brick according to claim 3, characterized in that: Curing in step 4: the formed bricks are first kept still for 1-2 days in an environment with a temperature of 20±2°C and a relative humidity of more than 90%, then transferred to a steam curing room, cured for 6-8 hours at a temperature of 80-90°C and a steam pressure of 0.1-0.15MPa, and naturally cooled to room temperature.

8. The process for preparing the unfired antique blue brick according to claim 3, characterized in that: In the forming step, the antique blue brick mold is designed according to the size of traditional blue bricks, and the size error of the brick after forming is controlled within ±1mm.

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