Bridge construction waste recycled static pressure brick and preparation method thereof

Abstract

This application relates to the field of solid waste utilization technology, specifically disclosing a method for preparing recycled static-pressure bricks from bridge construction waste. The method for preparing recycled static-pressure bricks from bridge construction waste includes the following steps: S1, mixing graded aggregates with sulfoaluminate cement, fly ash, and pigments, then adding water and stirring until homogeneous to obtain a mixture; S2, molding the mixture into bricks, curing them after molding, to obtain recycled static-pressure bricks; the graded aggregates are obtained by the following method: first, crushing and screening the bridge construction waste, then performing four-level grading of the aggregates, and mixing aggregates A, B, C, and D in a specific mass ratio to obtain graded aggregates. The method for preparing recycled static-pressure bricks in this application is simple, low-cost, environmentally friendly, and yields high-strength recycled static-pressure bricks with broad market prospects.

Description

Technical Field

[0001] This application relates to the field of solid waste utilization technology, and more specifically, it relates to a static pressure brick made from recycled bridge construction waste and its preparation method. Background Technology

[0002] With the development of my country's national economy and the acceleration of industrialization and urbanization, the pace of urbanization and new rural construction has also accelerated, leading to an unprecedented increase in the construction of various infrastructure projects. New buildings are springing up everywhere, giving old cities a new look. Construction waste is a major component of urban waste. Currently, the main methods for dealing with construction waste are traditional open-air dumping and deep landfilling. While these methods are convenient, simple, and inexpensive, they actually occupy land resources. If construction waste is not recycled in a timely manner, it not only pollutes the environment but also wastes resources.

[0003] Currently, aggregates made primarily from bridge construction waste are mixed with cementitious materials, organic adhesives, and additives to form recycled bricks. These mixtures are then molded through casting, static pressing, and vibration pressing. This waste-to-resource process not only reduces environmental pressure but also improves resource recycling rates. However, compared to natural sand and gravel aggregates, the resulting aggregates have higher porosity and lower strength, leading to brittle recycled bricks with low compressive strength. This significantly limits the application of recycled bricks in construction projects, thus necessitating efforts to improve their strength. Summary of the Invention

[0004] To address the problem of poor strength in existing recycled bricks made from construction waste, this application provides a method for preparing statically pressed bricks made from recycled bridge construction waste.

[0005] In the first aspect, this application provides a statically pressed brick made from recycled bridge construction waste, which adopts the following technical solution: A statically pressed brick made from recycled bridge construction waste includes the following raw materials in parts by weight: 60-100 parts of graded aggregate, 18-35 parts of sulfoaluminate cement, 8-20 parts of fly ash, 1-3 parts of pigment, and 15-30 parts of water.

[0006] By adopting the above technical solution, graded aggregates are obtained from bridge construction waste. The recycled static pressure bricks of this application use graded aggregates, sulfoaluminate cement, fly ash, pigments and water as the main raw materials, and control the weight of each raw material to promote the interaction between the components, which greatly improves the strength of the recycled static pressure bricks.

[0007] Secondly, this application provides a method for preparing statically pressed bricks made from recycled bridge construction waste, employing the following technical solution:

[0008] A method for preparing recycled static-pressed bricks from bridge construction waste includes the following steps:

[0009] S1. After mixing graded aggregate with sulfoaluminate cement, fly ash, and pigment, add water and stir evenly to obtain a mixture.

[0010] S2. The mixture is laid into bricks, and after molding and curing, recycled static pressure bricks are obtained.

[0011] The mass ratio of the graded aggregate, sulfoaluminate cement, fly ash, pigment, and water is 60-100:18-35:8-20:1-3:15-30; the graded aggregate is prepared by the following method:

[0012] First, the bridge construction waste is crushed and screened, with the maximum aggregate size being 15mm. Then, the aggregate is graded: 0-2mm aggregate is designated as aggregate A, 2-6mm aggregate as aggregate B, 6-10mm aggregate as aggregate C, and 10-15mm aggregate as aggregate D. Aggregates A, B, C, and D are then uniformly mixed at a mass ratio of 4:1-5:2:1-3 to obtain graded aggregate.

[0013] By adopting the above technical solution, bridge construction waste is crushed and screened, and then graded into aggregates in four stages according to the particle size. The mass ratio of each graded aggregate is controlled. The graded aggregate can effectively reduce the porosity of recycled static pressure bricks, improve their density, and enhance their strength. The graded aggregate is mixed with sulfoaluminate cement, fly ash, and pigments. Sulfoaluminate cement, as a cementing material, can reduce curing time and alleviate autogenous shrinkage, which is beneficial to enhancing the strength of recycled static pressure bricks. At the same time, the interaction between sulfoaluminate cement and fly ash can increase the cohesion of the graded aggregate and form a stable structure. By strictly controlling the mass ratio of the graded aggregate to sulfoaluminate cement, fly ash, pigments, and water, the bonding between the raw materials is strengthened, resulting in better mechanical properties of the recycled static pressure bricks, which can be widely used in the construction field.

[0014] Preferably, the graded aggregate can also be obtained by the following methods:

[0015] S11. First, crush the bridge construction waste and then screen it. The maximum particle size of the aggregate is 15mm. Then, the aggregate is graded. The particle size of 0-2mm is aggregate A, the particle size of 2-6mm is aggregate B, the particle size of 6-10mm is aggregate C, and the particle size of 10-15mm is aggregate D.

[0016] S12. Modify aggregate A and aggregate D respectively to obtain aggregate A dispersion and aggregate D complex;

[0017] S13. Mix aggregate A dispersion, aggregate B, aggregate C and aggregate D complex uniformly in a mass ratio of 4:1-5:2:1-3 to obtain graded aggregate.

[0018] By adopting the above technical solution, the graded aggregate of this application can also be obtained by mixing aggregate A dispersion, aggregate D composite, and aggregates B and C as raw materials; aggregate A dispersion and aggregate D composite can not only play their own role in reinforcing recycled static pressure bricks, but also have additional functions. Aggregate A dispersion can act as a dispersant, and aggregate D composite can act as a water-reducing agent; therefore, the graded aggregate of this application can further improve the strength of recycled static pressure bricks.

[0019] Preferably, the aggregate A dispersion is prepared by the following method:

[0020] First, add aggregate A to citric acid solution for acidification for 1-2 hours, filter, and dry to obtain activated aggregate A; then add activated aggregate A, sodium lignosulfonate, and N-methylpyrrolidone to water, ultrasonically disperse for 2-3 hours, freeze dry, and crush into particles with a particle size of less than 2.5 mm to obtain aggregate A dispersion.

[0021] Preferably, the mass ratio of aggregate A, citric acid solution, sodium lignosulfonate, N-methylpyrrolidone, and water is 10:20-30:2-5:1:10-15.

[0022] Preferably, the citric acid solution has a mass fraction of 30-50%.

[0023] Preferably, the conditions for ultrasonic dispersion are: power of 50-100W, frequency of 10-100kHz, and temperature of 40-60℃.

[0024] Preferably, the freeze-drying conditions are: temperature of (-20)-(-5)℃ and time of 3-5h.

[0025] By adopting the above technical solution, the particle size of aggregate A in this application is 0-2 mm, which is relatively small. In order to further improve the reinforcing effect of aggregate A in recycled static pressure bricks, this application improves the dispersibility of aggregate A. First, aggregate A is acidified with citric acid solution to load active groups on the surface of aggregate A, thus obtaining activated aggregate A. Then, taking advantage of the amphiphilic nature and cyclic conjugated structure of sodium lignosulfonate, it is adsorbed onto the surface of activated aggregate A, forming a double electric layer structure on activated aggregate A. Through electrostatic interaction, agglomeration between aggregate A particles is effectively avoided. In addition, the obtained aggregate A dispersion can not only act as a reinforcing agent, but also as a dispersant and water-reducing agent. It can significantly improve the flowability and plasticity of aggregate A dispersion, reduce the harmful porosity of recycled static pressure bricks, and significantly enhance the compressive strength of recycled static pressure bricks.

[0026] Preferably, the aggregate D complex is prepared by the following method:

[0027] After plasma pretreatment of aggregate D, it is added to cement coating liquid, soaked for 2-3 hours, filtered, and dried to obtain aggregate D composite.

[0028] Preferably, the plasma pretreatment conditions are as follows: the treatment medium is oxygen; the gas flow rate is 60-100 cm³ / h. 3 / min; plasma generation power is 100-400W; processing time is 300-600s.

[0029] Preferably, the mass ratio of aggregate D to cement coating liquid is 1:2-4.

[0030] Preferably, the cement coating liquid is obtained by mixing cement, larch tannin, nano zinc oxide and water in a mass ratio of 30-60:1-10:3:20-40.

[0031] By employing the above-mentioned technology, the aggregate D of this application has a particle size of 10-15 mm. Plasma treatment of aggregate D not only cleans the surface of aggregate D but also etches and activates the surface of aggregate D, improving its adhesion and bonding ability. Subsequently, aggregate D is added to a cement coating solution, which is obtained by mixing cement, larch tannin, nano zinc oxide, and water. The phenolic hydroxyl groups in larch tannin can complex with the metal ions in cement, forming a tightly structured film on the surface of aggregate D, effectively reducing the water absorption rate of aggregate D. Furthermore, larch tannin contains tannic acid, which can combine with calcium ions in aggregate D to form calcium tannate particles. The synergistic effect of calcium tannate and nano zinc oxide greatly reduces the porosity of aggregate D and enhances its density. The resulting aggregate D composite can effectively improve the structural stability and mechanical properties of recycled static pressure bricks.

[0032] Preferably, the pigment is at least one of phthalocyanine green, iron oxide green, iron oxide brown, and carbon black.

[0033] By adopting the above technical solution, the pigment of this application is at least one of phthalocyanine green, iron oxide green, iron oxide brown, and carbon black. The resulting recycled static pressure brick can be used as an antique-style blue brick, which is green and environmentally friendly, low in cost, and has significant social and economic benefits.

[0034] Preferably, the curing conditions are: curing for 3 days at a temperature of 18-22℃ and humidity ≥95%, followed by environmental curing; or curing for 8 hours at a temperature of 60℃ and humidity ≥95%, followed by environmental curing.

[0035] By adopting the above technical solution, this application strictly controls the curing conditions, effectively preventing internal cracking of recycled static pressure bricks, resulting in higher strength, better quality stability, and extended service life.

[0036] In summary, this application has the following beneficial effects:

[0037] 1. This application uses bridge construction waste as a base material to replace the clay used in the prior art. It does not require a large amount of natural resources. Furthermore, by adjusting the gradation of the aggregate from the bridge construction waste, the density of the recycled static pressure bricks is improved, thereby enhancing the performance of the recycled static pressure bricks. This achieves the harmlessness, reduction, and resource utilization of bridge construction waste, significantly reducing raw material input and making it green and environmentally friendly.

[0038] 2. The construction waste aggregates of this application are crushed and screened, and then subjected to four-stage gradation to obtain aggregates A, B, C and D. These aggregates are then mixed with sulfoaluminate cement, fly ash and pigments, which effectively reduces the porosity of the recycled static pressure bricks. Furthermore, the use of sulfoaluminate cement as a cementing material improves the self-shrinkage problem of the recycled static pressure bricks. The resulting recycled static pressure bricks have excellent mechanical properties and have significant theoretical and engineering application value.

[0039] 3. The graded aggregate of this application is modified by mixing aggregate A dispersion, aggregate B, aggregate C and aggregate D composite, which improves the bonding ability between the graded aggregate and other raw materials, further inhibits the generation and development of microcracks in recycled static pressure bricks, and improves the crack resistance and durability of recycled static pressure bricks. Detailed Implementation

[0040] The present application will be further described in detail below with reference to the embodiments.

[0041] Preparation Examples 1-6 and Comparative Preparation Examples 1-10 provide methods for preparing graded aggregates.

[0042] Preparation Example 1

[0043] Graded aggregates are prepared by the following methods:

[0044] First, 200 kg of bridge construction waste is crushed and screened, with the maximum aggregate size being 15 mm. Then, the aggregate is graded: 0-2 mm is aggregate A, 2-6 mm is aggregate B, 6-10 mm is aggregate C, and 10-15 mm is aggregate D. 40 kg of aggregate A, 10 kg of aggregate B, 20 kg of aggregate C, and 10 kg of aggregate D are then mixed evenly to obtain graded aggregate.

[0045] Preparation Example 2

[0046] Graded aggregates are prepared by the following methods:

[0047] First, 200 kg of bridge construction waste is crushed and screened, with the maximum particle size of the aggregate being 15 mm. Then, the aggregate is graded: 0-2 mm is aggregate A, 2-6 mm is aggregate B, 6-10 mm is aggregate C, and 10-15 mm is aggregate D. 40 kg of aggregate A, 30 kg of aggregate B, 20 kg of aggregate C, and 20 kg of aggregate D are mixed evenly to obtain graded aggregate.

[0048] Preparation Example 3

[0049] Graded aggregates are prepared by the following methods:

[0050] First, 200 kg of bridge construction waste is crushed and screened, with the maximum aggregate size being 15 mm. Then, the aggregate is graded: 0-2 mm is aggregate A, 2-6 mm is aggregate B, 6-10 mm is aggregate C, and 10-15 mm is aggregate D. 40 kg of aggregate A, 50 kg of aggregate B, 20 kg of aggregate C, and 30 kg of aggregate D are mixed evenly to obtain graded aggregate.

[0051] Preparation Example 4

[0052] Graded aggregates are prepared by the following methods:

[0053] S11. First, crush 200 kg of bridge construction waste and then screen it. The maximum particle size of the aggregate is 15 mm. Then, the aggregate is graded. The particle size of 0-2 mm is aggregate A, the particle size of 2-6 mm is aggregate B, the particle size of 6-10 mm is aggregate C, and the particle size of 10-15 mm is aggregate D.

[0054] S12. First, add 50 kg of aggregate A to 100 kg of 30% citric acid solution and acidify at 600 r / min for 1 hour. Filter and dry to obtain activated aggregate A. Then, add activated aggregate A, 10 kg of sodium lignosulfonate, and 5 kg of N-methylpyrrolidone to 50 kg of water. Disperse ultrasonically at 50 W, 10 kHz, and 40 °C for 2 hours. Freeze-dry at -20 °C for 3 hours, then crush into particles smaller than 2.5 mm to obtain aggregate A dispersion. S13. Take 20 kg of aggregate D and pretreat it using plasma as the treatment medium at a flow rate of 60 cm³ / h. 3 The plasma generation power was 100W / min, and the processing time was 300s. Then, aggregate D was added to 40kg of cement coating liquid, soaked for 2h, filtered, and dried to obtain aggregate D composite.

[0055] The cement coating solution is prepared by mixing 30kg of cement, 1kg of larch tannin, 3kg of nano zinc oxide and 20kg of water at a speed of 200r / min for 1 hour.

[0056] S14. Stir 40 kg of aggregate A dispersion obtained in step S12, 10 kg of aggregate B obtained in step S11, 20 kg of aggregate C obtained in step S11, and 10 kg of aggregate D complex obtained in step S13 at a speed of 200 r / min for 20 min to obtain graded aggregate.

[0057] Preparation Example 5

[0058] Graded aggregates are prepared by the following methods:

[0059] S11. First, crush the bridge construction waste and then screen it. The maximum particle size of the aggregate is 15mm. Then, the aggregate is graded. The particle size of 0-2mm is aggregate A, the particle size of 2-6mm is aggregate B, the particle size of 6-10mm is aggregate C, and the particle size of 10-15mm is aggregate D.

[0060] S12. First, add 50 kg of aggregate A to 120 kg of 40% citric acid solution and acidify at 700 r / min for 1.5 h. Filter and dry to obtain activated aggregate A. Then, add activated aggregate A, 15 kg of sodium lignosulfonate, and 5 kg of N-methylpyrrolidone to 60 kg of water. Disperse ultrasonically at 70 W, 50 kHz, and 50 °C for 2.5 h. Freeze-dry at -12 °C for 4 h. Then crush into particles with a particle size of less than 2.5 mm to obtain aggregate A dispersion.

[0061] S13. Take 20 kg of aggregate D and pretreat it using plasma. The treatment medium is oxygen, and the gas flow rate is 80 cm³ / kg. 3 The plasma generation power was 250W / min, and the processing time was 450s. Then, aggregate D was added to 60kg of cement coating liquid, soaked for 2.5h, filtered, and dried to obtain aggregate D composite.

[0062] The cement coating solution is prepared by mixing 50kg of cement, 5kg of larch tannin, 3kg of nano zinc oxide and 30kg of water at a speed of 600r / min for 2 hours.

[0063] S14. Stir 40 kg of aggregate A dispersion obtained in step S12, 10 kg of aggregate B obtained in step S11, 20 kg of aggregate C obtained in step S11, and 10 kg of aggregate D complex obtained in step S13 at a speed of 200 r / min for 20 min to obtain graded aggregate.

[0064] Preparation Example 6

[0065] Graded aggregates are prepared by the following methods:

[0066] S11. First, crush the bridge construction waste and then screen it. The maximum particle size of the aggregate is 15mm. Then, the aggregate is graded. The particle size of 0-2mm is aggregate A, the particle size of 2-6mm is aggregate B, the particle size of 6-10mm is aggregate C, and the particle size of 10-15mm is aggregate D.

[0067] S12. First, add 50 kg of aggregate A to 120 kg of 50% citric acid solution and acidify at 800 r / min for 2 h. Filter and dry to obtain activated aggregate A. Then, add activated aggregate A, 150 kg of sodium lignosulfonate, and 5 kg of N-methylpyrrolidone to 75 kg of water. Ultrasonically disperse the aggregate A for 3 h at 100 W, 100 kHz, and 60 °C. Freeze-dry the aggregate A for 5 h at -5 °C and then crush it into particles with a particle size of less than 2.5 mm to obtain aggregate A dispersion.

[0068] S13. Take 20 kg of aggregate D and pretreat it using plasma. The treatment medium is oxygen, and the gas flow rate is 100 cm³ / kg. 3 The plasma generation power was 400W, and the processing time was 600s. Then, aggregate D was added to 80kg of cement coating liquid, soaked for 3h, filtered, and dried to obtain aggregate D composite.

[0069] The cement coating solution is prepared by mixing 60kg of cement, 10kg of larch tannin, 3kg of nano zinc oxide and 40kg of water at a speed of 600r / min for 2 hours.

[0070] S14. Stir 40 kg of aggregate A dispersion obtained in step S12, 10 kg of aggregate B obtained in step S11, 20 kg of aggregate C obtained in step S11, and 10 kg of aggregate D complex obtained in step S13 at a speed of 200 r / min for 20 min to obtain graded aggregate.

[0071] Comparative Preparation Example 1

[0072] Graded aggregates are prepared by the following methods:

[0073] After crushing 200 kg of bridge construction waste, it was screened to obtain aggregates with a maximum particle size of 15 mm and a particle size range of 0-15 mm as the graded aggregate.

[0074] Comparative Preparation Example 2

[0075] Graded aggregates are prepared by the following methods:

[0076] First, 200 kg of bridge construction waste is crushed and screened. The maximum particle size of the aggregate is 15 mm. Then, the aggregate is graded. The particle size of 0-6 mm is aggregate B, and the particle size of 6-15 mm is aggregate C. 50 kg of aggregate A and 30 kg of aggregate B are mixed evenly to obtain graded aggregate.

[0077] Comparative preparation example 3

[0078] Graded aggregates are prepared by the following methods:

[0079] First, 200 kg of bridge construction waste is crushed and screened. The maximum particle size of the aggregate is 15 mm. Then, the aggregate is graded: 0-5 mm is aggregate A, 5-10 mm is aggregate B, and 11-15 mm is aggregate C. 40 kg of aggregate A, 30 kg of aggregate B, and 20 kg of aggregate C are mixed evenly to obtain graded aggregate.

[0080] Comparative preparation example 4

[0081] Graded aggregates are prepared by the following methods:

[0082] S11. First, crush 200 kg of bridge construction waste and then screen it. The maximum particle size of the aggregate is 15 mm. Then, the aggregate is graded. The particle size of 0-2 mm is aggregate A, the particle size of 2-6 mm is aggregate B, the particle size of 6-10 mm is aggregate C, and the particle size of 10-15 mm is aggregate D.

[0083] S12. First, add 50 kg of aggregate A to 100 kg of 30% citric acid solution and acidify at 600 r / min for 1 h. Filter and dry to obtain activated aggregate A. Then, add activated aggregate A, 10 kg of sodium lignosulfonate, and 5 kg of N-methylpyrrolidone to 50 kg of water. Ultrasonically disperse at 50 W, 10 kHz, and 40 °C for 2 h. Freeze-dry at -20 °C for 3 h. Then, crush into particles with a particle size of less than 2.5 mm to obtain aggregate A dispersion. S13. Stir 40 kg of aggregate A dispersion obtained in step S12, 10 kg of aggregate B obtained in step S11, 20 kg of aggregate C obtained in step S11, and 10 kg of aggregate D obtained in step S11 at 200 r / min for 20 min to obtain graded aggregate.

[0084] Comparative preparation example 5

[0085] Graded aggregates are prepared by the following methods:

[0086] S11. First, crush 200 kg of bridge construction waste and then screen it. The maximum particle size of the aggregate is 15 mm. Then, the aggregate is graded. The particle size of 0-2 mm is aggregate A, the particle size of 2-6 mm is aggregate B, the particle size of 6-10 mm is aggregate C, and the particle size of 10-15 mm is aggregate D.

[0087] S12. Take 10 kg of aggregate D and pretreat it using plasma. The treatment medium is oxygen, and the gas flow rate is 60 cm³ / kg. 3 The plasma generation power was 100W / min, and the processing time was 300s. Then, aggregate D was added to 40kg of cement coating liquid, soaked for 2h, filtered, and dried to obtain aggregate D composite.

[0088] The cement coating solution is prepared by mixing 30kg of cement, 1kg of larch tannin, 3kg of nano zinc oxide and 20kg of water at a speed of 200r / min for 1 hour.

[0089] S13. Mix 40 kg of aggregate A obtained in step S11, 10 kg of aggregate B obtained in step S11, 20 kg of aggregate C obtained in step S11, and 10 kg of aggregate D obtained in step S12 at a speed of 200 r / min for 20 min to obtain graded aggregate.

[0090] Comparative preparation example 6

[0091] Graded aggregates are prepared by the following methods:

[0092] S11. First, crush 200 kg of bridge construction waste and then screen it. The maximum particle size of the aggregate is 15 mm. Then, the aggregate is graded. The particle size of 0-2 mm is aggregate A, the particle size of 2-6 mm is aggregate B, the particle size of 6-10 mm is aggregate C, and the particle size of 10-15 mm is aggregate D.

[0093] S12. Add 50kg of aggregate A, 10kg of sodium lignosulfonate and 5kg of N-methylpyrrolidone to 50kg of water. Disperse the aggregate A by ultrasonication for 2 hours at a power of 50W, a frequency of 10kHz and a temperature of 40℃. Then freeze-dry the aggregate A at a temperature of -20℃ for 3 hours. Finally, crush the aggregate A into particles with a particle size of less than 2.5mm to obtain the aggregate A dispersion.

[0094] S13. Take 10 kg of aggregate D and pretreat it using plasma. The treatment medium is oxygen, and the gas flow rate is 60 cm³ / kg. 3 The plasma generation power was 100W / min, and the processing time was 300s. Then, aggregate D was added to 40kg of cement coating liquid, soaked for 2h, filtered, and dried to obtain aggregate D composite.

[0095] The cement coating solution is prepared by mixing 30kg of cement, 1kg of larch tannin, 3kg of nano zinc oxide and 20kg of water at a speed of 200r / min for 1 hour.

[0096] S14. Stir 40 kg of aggregate A dispersion obtained in step S12, 10 kg of aggregate B obtained in step S11, 20 kg of aggregate C obtained in step S11, and 10 kg of aggregate D complex obtained in step S13 at a speed of 200 r / min for 20 min to obtain graded aggregate.

[0097] Comparative preparation example 6

[0098] Graded aggregates are prepared by the following methods:

[0099] S11. First, crush 200 kg of bridge construction waste and then screen it. The maximum particle size of the aggregate is 15 mm. Then, the aggregate is graded. The particle size of 0-2 mm is aggregate A, the particle size of 2-6 mm is aggregate B, the particle size of 6-10 mm is aggregate C, and the particle size of 10-15 mm is aggregate D.

[0100] S12. First, add 50 kg of aggregate A to 100 kg of 30% citric acid solution and acidify at 600 r / min for 1 hour. Filter and dry to obtain activated aggregate A. Then, add activated aggregate A, 10 kg of sodium lignosulfonate, and 5 kg of N-methylpyrrolidone to 50 kg of water. Disperse ultrasonically at 50 W, 10 kHz, and 40 °C for 2 hours. Freeze-dry at -20 °C for 3 hours, then crush into particles smaller than 2.5 mm to obtain aggregate A dispersion. S13. Take 20 kg of aggregate D and pretreat it using plasma as the treatment medium at a flow rate of 60 cm³ / h. 3 The plasma generation power was 100W, and the processing time was 300s. Then, aggregate D was added to 40kg of cement coating liquid, soaked for 2h, filtered, and dried to obtain aggregate D composite.

[0101] The cement coating solution is prepared by mixing 30kg of cement, 1kg of larch tannin, 3kg of nano zinc oxide and 20kg of water at a speed of 200r / min for 1 hour.

[0102] S14. Stir 40 kg of aggregate A dispersion obtained in step S12, 10 kg of aggregate B obtained in step S11, 20 kg of aggregate C obtained in step S11, and 10 kg of aggregate D complex obtained in step S13 at a speed of 200 r / min for 20 min to obtain graded aggregate.

[0103] Comparative Preparation Example 8

[0104] Compared with Preparation Example 4, the difference in Preparation Example 8 is that the cement coating liquid was prepared by mixing 30 kg of cement and 20 kg of water at a speed of 200 r / min for 1 h.

[0105] Comparative preparation example 9

[0106] Compared with Preparation Example 4, the difference in Preparation Example 9 is that the cement coating liquid was prepared by mixing 30 kg of cement, 10 kg of larch tannin and 20 kg of water at a speed of 200 r / min for 1 h.

[0107] Comparative preparation example 10

[0108] Compared with Preparation Example 4, the difference in Preparation Example 10 is that the cement coating liquid was prepared by mixing 30 kg of cement, 3 kg of nano zinc oxide and 20 kg of water at a speed of 200 r / min for 1 h.

[0109] Examples 1-6 provide a method for preparing statically pressed bricks made from recycled bridge construction waste.

[0110] Example 1

[0111] A method for preparing recycled static-pressed bricks from bridge construction waste includes the following steps:

[0112] S1. Take 60kg of graded aggregate, 18kg of sulfoaluminate cement, 20kg of fly ash, and 1kg of pigment. Stir at 200r / min for 20min, then add 15kg of water and continue stirring at the same speed for 1h to obtain the mixture.

[0113] The graded aggregate was prepared in Preparation Example 1; the pigment was prepared by mixing phthalocyanine green, iron oxide green, iron oxide brown and carbon black in a mass ratio of 1:1:1:1.

[0114] S2. The mixture is fed into a block molding machine and formed. Then it is cured for 3 days at a temperature of 18°C ​​and a humidity of 95%, and then environmental curing is adopted to obtain recycled static pressure bricks.

[0115] Example 2

[0116] A method for preparing recycled static-pressed bricks from bridge construction waste includes the following steps:

[0117] S1. Take 80kg of graded aggregate, 25kg of sulfoaluminate cement, 12kg of fly ash, and 1.2kg of pigment. Stir at 300r / min for 30min, then add 24kg of water and continue stirring at the same speed for 1.5h to obtain the mixture.

[0118] The graded aggregate was prepared in Preparation Example 2; the pigment was prepared by mixing phthalocyanine green, iron oxide green, iron oxide brown and carbon black in a mass ratio of 1:1:1:1.

[0119] S2. The mixture is fed into a block molding machine and formed. Then it is cured for 3 days at a temperature of 22°C and a humidity of 98%, and then environmental curing is adopted to obtain recycled static pressure bricks.

[0120] Example 3

[0121] A method for preparing recycled static-pressed bricks from bridge construction waste includes the following steps:

[0122] S1. Take 100kg of graded aggregate, 35kg of sulfoaluminate cement, 8kg of fly ash, and 3kg of pigment. Mix them at 400r / min for 20min. Then add 30kg of water and continue mixing at the same speed for 1h to obtain the mixture.

[0123] The graded aggregate was prepared in Preparation Example 3; the pigment was prepared by mixing phthalocyanine green, iron oxide green, iron oxide brown and carbon black in a mass ratio of 1:1:1:1.

[0124] S2. The mixture is fed into a block molding machine and then cured for 8 hours at a temperature of 60°C and a humidity of 100%. After that, it is cured in an environmental environment to obtain recycled static pressure bricks.

[0125] Example 4

[0126] Example 4 differs from Example 1 in that the graded aggregate was prepared in Example 4.

[0127] Example 5

[0128] Example 5 differs from Example 1 in that the graded aggregate was prepared from Preparation Example 5.

[0129] Example 6

[0130] Example 6 differs from Example 1 in that the graded aggregate was prepared in Example 6.

[0131] To verify the performance of the recycled static pressure bricks provided in this application, the applicant has set up comparative examples 1-10, in which:

[0132] Comparative Example 1

[0133] Comparative Example 1 differs from Example 1 in that the graded aggregate was prepared from Comparative Preparation Example 1.

[0134] Comparative Example 2

[0135] Comparative Example 2 differs from Example 1 in that the graded aggregate was prepared from Comparative Preparation Example 2.

[0136] Comparative Example 3

[0137] Comparative Example 3 differs from Example 1 in that the graded aggregate was prepared from Comparative Preparation Example 3.

[0138] Comparative Example 4

[0139] Comparative Example 4 differs from Example 4 in that the graded aggregate was prepared from Comparative Preparation Example 4.

[0140] Comparative Example 5

[0141] Comparative Example 5 differs from Example 4 in that the graded aggregate was prepared from Comparative Preparation Example 5.

[0142] Comparative Example 6

[0143] Comparative Example 6 differs from Example 4 in that the graded aggregate was prepared from Comparative Preparation Example 6.

[0144] Comparative Example 7

[0145] Comparative Example 7 differs from Example 4 in that the graded aggregate was prepared from Comparative Preparation Example 7.

[0146] Comparative Example 8

[0147] Comparative Example 8 differs from Example 4 in that the graded aggregate was prepared from Comparative Preparation Example 8.

[0148] Comparative Example 9

[0149] Comparative Example 9 differs from Example 4 in that the graded aggregate was prepared from Comparative Preparation Example 9.

[0150] Comparative Example 10

[0151] Comparative Example 10 differs from Example 4 in that the graded aggregate was prepared from Comparative Preparation Example 10.

[0152] The main properties of the recycled static pressure bricks obtained in Examples 1-6 and Comparative Examples 1-10 were tested respectively, and the following results were obtained, as shown in Table 1:

[0153] The compressive strength and flexural strength of recycled static pressure bricks (240×50×50mm) were tested after 28 days of curing, in accordance with the "Standard for Test Methods of Basic Mechanical Properties of Masonry" GB / T50129-2011. The results are shown in Table 1.

[0154] Table 1:

[0155] Compressive strength / MPa Flexural strength / MPa Are there cracks in the cross-section? Example 1 33.82 12.23 Very few micro cracks Example 2 36.91 15.46 Fewer microcracks Example 3 34.12 13.26 Fewer microcracks Example 4 42.16 17.26 Almost no cracks Example 5 45.85 20.51 Almost no cracks Example 6 43.12 19.46 Almost no cracks Comparative Example 1 18.16 7.46 Many large cracks Comparative Example 2 22.57 9.42 Many large cracks Comparative Example 3 26.68 10.56 Numerous fine cracks Comparative Example 4 34.12 13.86 Fewer microcracks Comparative Example 5 36.75 14.07 Fewer micro cracks Comparative Example 6 40.32 16.28 Fewer microcracks Comparative Example 7 39.12 15.45 Fewer micro cracks Comparative Example 8 37.42 14.16 Fewer micro cracks Comparative Example 9 40.47 16.78 Fewer microcracks Comparative Example 10 38.39 15.14 Fewer microcracks

[0156] As can be seen from the data shown in Table 1 above, the recycled static pressure bricks obtained in Examples 1-6 of this application have excellent performance, indicating that the recycled static pressure bricks of this application have broad application prospects.

[0157] As can be seen from Examples 1 and 4-6, the graded aggregate of Example 1 was prepared by mixing aggregate A, aggregate B, aggregate C and aggregate D. Compared with the graded aggregate of Examples 4-6, which was prepared by mixing aggregate A dispersion, aggregate B, aggregate C and aggregate D composite, the compressive strength and flexural strength of the recycled static pressure bricks obtained in Examples 4-6 are higher than those in Example 1, and the cross-section is almost free of cracks. This shows that the graded aggregate obtained by mixing aggregate A dispersion, aggregate B, aggregate C and aggregate D composite is beneficial to further improve the strength of recycled static pressure bricks.

[0158] As can be seen from Example 1 and Comparative Examples 1-3: the graded aggregate of Example 1 was prepared by Preparation Example 1 and the graded aggregate was four-graded; the graded aggregate of Comparative Example 1 was prepared by Comparative Preparation Example 1 and the aggregate was one-graded; the graded aggregate of Comparative Example 2 was prepared by Comparative Preparation Example 2 and the aggregate was two-graded; and the graded aggregate of Comparative Example 3 was prepared by Comparative Preparation Example 3 and the aggregate was three-graded. The strength of the recycled static pressure bricks obtained in Example 1 was significantly enhanced, and the cracks in the cross-section were significantly reduced, indicating that four-graded aggregate can greatly improve the problem of poor strength of recycled static pressure bricks.

[0159] As can be seen from Example 4 and Comparative Example 4, the graded aggregate of Example 4 was prepared by Preparation Example 4, which was obtained by mixing aggregate A dispersion, aggregate B, aggregate C and aggregate D composite. The graded aggregate of Comparative Example 4 was prepared by Comparative Preparation Example 4, and the graded aggregate was a mixture of aggregate A dispersion, aggregate B, aggregate C and aggregate D. The compressive strength of the recycled static pressure brick obtained in Comparative Example 4 was reduced, indicating that aggregate D composite helps to enhance the mechanical properties of the recycled static pressure brick.

[0160] As can be seen from Example 4 and Comparative Example 5, the graded aggregate of Example 4 was prepared by Preparation Example 4, which was obtained by mixing aggregate A dispersion, aggregate B, aggregate C and aggregate D complex. The graded aggregate of Comparative Example 5 was prepared by Comparative Preparation Example 5, which was a mixture of aggregate A, aggregate B, aggregate C and aggregate D complex. The recycled static pressure brick obtained in Example 5 has better strength, indicating that aggregate A dispersion is more beneficial than aggregate A in improving the performance of recycled static pressure brick.

[0161] As can be seen from Example 4 and Comparative Example 6: The graded aggregate of Example 4 was prepared by Preparation Example 4. The aggregate A dispersion was obtained by first acidifying aggregate A with citric acid solution and then mixing it with sodium lignosulfonate and N-methylpyrrolidone. The graded aggregate of Comparative Example 6 was prepared by Comparative Preparation Example 6. The aggregate A dispersion was obtained by directly mixing aggregate A with sodium lignosulfonate and N-methylpyrrolidone without acidifying it with citric acid solution. The regenerated static pressure bricks obtained in Example 4 have higher compressive strength, indicating that citric acid solution can activate the surface of aggregate A, thereby improving the bonding between aggregate A and sodium lignosulfonate and forming an aggregate A dispersion with better dispersibility.

[0162] As can be seen from Example 4 and Comparative Example 7: the graded aggregate of Example 4 was prepared by Preparation Example 4, and the aggregate D composite was obtained by first treating aggregate D with plasma and then coating it with cement coating liquid. In contrast, the graded aggregate of Comparative Example 7 was prepared by Preparation Example 7, and the aggregate D composite was obtained by directly coating aggregate D with cement coating liquid without plasma treatment. The recycled static pressure brick obtained in Example 4 showed almost no cracks during fracture, indicating that the plasma-treated aggregate D can be better coated by cement coating liquid, resulting in an aggregate D composite with low water absorption and high strength.

[0163] As can be seen from Example 4 and Comparative Examples 8-10, the graded aggregate of Example 4 was prepared by Example 4, and the cement coating liquid was obtained by mixing cement, larch tannin, nano zinc oxide and water. Compared with Comparative Examples 8-10, the recycled static pressure bricks obtained in Example 4 have better comprehensive performance, indicating that the interaction between the components in the cement coating liquid effectively improves the overall performance of aggregate D composite, thereby enhancing the mechanical properties of the recycled static pressure bricks.

[0164] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A type of statically pressed brick made from recycled bridge construction waste, characterized in that, The raw materials include the following parts by weight: 60-100 parts graded aggregate, 18-35 parts sulfoaluminate cement, 8-20 parts fly ash, 1-3 parts pigment, and 15-30 parts water; The graded aggregate is obtained by the following method: S11. First, crush the bridge construction waste and then screen it. The maximum particle size of the aggregate is 15mm. Then, the aggregate is graded. The particle size of 0-2mm is aggregate A, the particle size of 2-6mm is aggregate B, the particle size of 6-10mm is aggregate C, and the particle size of 10-15mm is aggregate D. S12. Modify aggregate A and aggregate D respectively to obtain aggregate A dispersion and aggregate D complex; S13. Mix aggregate A dispersion, aggregate B, aggregate C and aggregate D complex uniformly at a mass ratio of 4:1-5:2:1-3 to obtain graded aggregate; The aggregate A dispersion is prepared by the following method: First, add aggregate A to citric acid solution for acidification for 1-2 hours, filter, and dry to obtain activated aggregate A; then add activated aggregate A, sodium lignosulfonate, and N-methylpyrrolidone to water, ultrasonically disperse for 2-3 hours, freeze dry, and crush into particles with a particle size of less than 2.5 mm to obtain aggregate A dispersion. The aggregate D complex is prepared by the following method: After plasma pretreatment of aggregate D, it is added to cement coating liquid, soaked for 2-3 hours, filtered, and dried to obtain aggregate D composite. The cement coating liquid is obtained by mixing cement, larch tannin, nano zinc oxide and water in a mass ratio of 30-60:1-10:3:20-40.

2. The bridge construction waste recycled static pressure brick according to claim 1, characterized in that, The aggregate A dispersion is prepared by the following method: The mass ratio of aggregate A, citric acid solution, sodium lignosulfonate, N-methylpyrrolidone, and water is 10:20-30:2-5:1:10-15.

3. The bridge construction waste recycled static pressure brick according to claim 1, characterized in that, The mass ratio of aggregate D to cement coating liquid is 1:2-4.

4. The method for preparing recycled static-pressure bricks from bridge construction waste according to claim 1, characterized in that, A method for preparing recycled static-pressed bricks from bridge construction waste includes the following steps: S1. After mixing graded aggregate with sulfoaluminate cement, fly ash, and pigment, add water and stir evenly to obtain a mixture. S2. The mixture is laid into bricks, and after molding and curing, recycled static pressure bricks are obtained. The mass ratio of the graded aggregate, sulfoaluminate cement, fly ash, pigment and water is 60-100:18-35:8-20:1-3:15-30; The graded aggregate is obtained by the following method: S11. First, crush the bridge construction waste and then screen it. The maximum particle size of the aggregate is 15mm. Then, the aggregate is graded. The particle size of 0-2mm is aggregate A, the particle size of 2-6mm is aggregate B, the particle size of 6-10mm is aggregate C, and the particle size of 10-15mm is aggregate D. S12. Modify aggregate A and aggregate D respectively to obtain aggregate A dispersion and aggregate D complex; S13. Mix aggregate A dispersion, aggregate B, aggregate C and aggregate D complex uniformly at a mass ratio of 4:1-5:2:1-3 to obtain graded aggregate; The aggregate A dispersion is prepared by the following method: First, add aggregate A to citric acid solution for acidification for 1-2 hours, filter, and dry to obtain activated aggregate A; then add activated aggregate A, sodium lignosulfonate, and N-methylpyrrolidone to water, ultrasonically disperse for 2-3 hours, freeze dry, and crush into particles with a particle size of less than 2.5 mm to obtain aggregate A dispersion. The aggregate D complex is prepared by the following method: After plasma pretreatment of aggregate D, it is added to cement coating liquid, soaked for 2-3 hours, filtered, and dried to obtain aggregate D composite. The cement coating liquid is obtained by mixing cement, larch tannin, nano zinc oxide and water in a mass ratio of 30-60:1-10:3:20-40.

5. The method for preparing recycled static-pressure bricks from bridge construction waste according to claim 4, characterized in that, The curing conditions are as follows: curing for 3 days at a temperature of 18-22℃ and humidity ≥95%, followed by environmental curing; or curing for 8 hours at a temperature of 60℃ and humidity ≥95%, followed by environmental curing.