A mixing processing method of bamboo aggregate concrete

Abstract

A kind of mixing processing method of bamboo aggregate concrete, it is characterized in that natural bamboo is cut into block particles, and is treated to form a new type of bamboo aggregate, then the bamboo aggregate is replaced by gravel, pebble, ceramsite and other inorganic coarse aggregate, and a new type of bamboo aggregate concrete is mixed.The waterproof and corrosion-resistant performance and mechanical properties of the new type of bamboo aggregate are significantly improved, and the surface roughness is improved, the cementing property with cement is good during the mixing process of concrete, so that the workability of bamboo aggregate concrete is better, and the slump loss is smaller.The bamboo aggregate concrete mixed by the mixing method fully utilizes the advantages of high compressive strength and high strength-weight ratio of bamboo aggregate.In addition, the mixing processing method provided by the present application is simple to operate, easy to process, high in economic benefit, uses renewable and sustainable bamboo as building material, is green and environmentally friendly, and has high ecological benefit.

Description

Technical Field

[0001] This invention specifically relates to a method for mixing and processing bamboo aggregate concrete, belonging to the field of civil engineering. Background Technology

[0002] Bamboo has become a promising and noteworthy building material due to its environmental friendliness, sustainability, and ease of recycling. Bamboo grows rapidly, reaching harvest time within 3-5 years; compared to other common construction materials such as wood and wood-based composites, bamboo also boasts superior specific strength. From a construction perspective, bamboo is easy to process and meets building safety requirements, while also being lightweight, having low shrinkage, high modulus of elasticity, and high radial tensile strength. The texture and hollow structure of bamboo also contribute to its excellent thermal insulation properties. As a lightweight material, bamboo saves costs and labor during construction. Currently, bamboo is used in civil engineering in two main forms: raw bamboo and glued bamboo composites.

[0003] In concrete, sand and gravel aggregates are one of the essential raw materials for infrastructure construction. With the continuous development of the construction industry, sand and gravel aggregates have become the product consuming the largest amount of solid resources, and this trend is increasing year by year. Due to environmental protection and restrictions on the mining of natural sand and gravel, there is a current situation where the supply of inorganic aggregates such as sand and gravel cannot meet the demand, and prices continue to rise. Therefore, finding a renewable and sustainable building material as a new type of aggregate to replace inorganic aggregates such as sand and gravel, and solving the problem of sand and gravel aggregate shortage, is of great significance to the future of the construction industry. At the same time, in the global context of pursuing green and low-carbon economic development, it is even more important to manufacture a lightweight, green, and renewable material to replace traditional concrete.

[0004] Existing concrete mainly consists of cement, fine aggregate, coarse aggregate, and water. Commonly used cement types include ordinary Portland cement, fly ash cement, and slag cement. Conventional fine aggregates include river sand, manufactured sand, desalinated sea sand, and mountain sand. Coarse aggregates include crushed stone, gravel, and pebbles, as well as artificial aggregates such as recycled concrete and steel slag. Admixtures include water-reducing agents, retarders, and air-entraining agents. Admixtures include slag, fly ash, and silica fume. The components of this type of conventional concrete mix and set together to achieve the mechanical properties required for the concrete structure. Conventional concrete mixing methods include manual mixing and mechanical mixing. Regardless of the mixing method, the cement in the concrete can effectively disperse and coat the fine and coarse aggregates. However, conventional concrete component mixing and methods are insufficient for achieving good mechanical properties in concrete using biomass aggregates such as bamboo. Summary of the Invention

[0005] This invention provides a method for mixing and processing bamboo aggregate concrete. The bamboo aggregate is made from natural bamboo through cutting and surface treatment. The bamboo aggregate concrete is formed by replacing inorganic coarse aggregates such as crushed stone, pebbles, and expanded clay with bamboo aggregate. The surface-treated bamboo aggregate exhibits significantly improved waterproof and corrosion-resistant properties, as well as enhanced mechanical properties. Furthermore, its increased surface roughness improves its adhesion to cementitious materials, resulting in better workability and less slump loss in the bamboo aggregate concrete. The bamboo aggregate concrete prepared using this method fully utilizes the advantages of bamboo aggregate, such as high tensile strength, high strength-to-weight ratio, high rigidity and toughness, and low density. This results in a lightweight, high-strength, and well-deformable concrete. In addition, the mixing and processing method provided by this invention significantly improves the utilization rate of bamboo materials, is simple to operate, easy to process, and offers good economic and ecological benefits, addressing the current problems of scarce building materials and environmental damage.

[0006] The technical solution of this invention: a method for mixing and processing bamboo aggregate concrete, characterized by the following construction steps:

[0007] 1) Cutting bamboo ribs: Select bamboo that is over 3 years old and has no obvious diseases, pests and damage. Remove the green and yellow parts of the bamboo. Break the hollow round bamboo tubes or split the hollow round bamboo tubes into bamboo strips and then tie multiple bamboo strips together and cut them into new block bamboo ribs. The length-to-diameter ratio of the bamboo ribs is 1 to 3 and the size is 2mm to 30mm.

[0008] 2) Surface Treatment of Bamboo Frames: A method involving pre-coating with cement slurry, applying adhesive, and bonding sand is used to treat the surface of the bamboo frames. Before surface treatment, contaminants are removed to ensure a smooth and clean surface. For pre-coating with cement slurry, cement and bamboo frames are added to a container in batches and mixed. Then, a predetermined amount of water is added, with a water-cement ratio of 0.4–0.6. Simultaneously, an adhesive with a ratio of 1:10 to 1:5 to the cement slurry is added and mixed for 5–15 minutes to enhance the bond between the cement slurry and the bamboo frames. For applying adhesive, the adhesive is pre-mixed and then applied in one layer to the surface of the bamboo frames. The application method is as follows: This includes brushing, rolling, and spraying. After the bamboo aggregate is pre-coated with cement slurry and adhesive, it is left to stand indoors for 24 hours. The coverage of the cement slurry or adhesive is then checked, and touch-ups are made to ensure that the surface of the bamboo aggregate is completely covered by the cement slurry or adhesive and that the cement slurry or adhesive does not flow naturally. The total coating thickness of the cement slurry or adhesive is 0.05mm to 1.0mm. When applying sand, a layer of sand is evenly sprinkled on the surface of the wet bamboo aggregate after the adhesive has been applied. The sand is densely distributed on the surface of the bamboo aggregate. Areas with large gaps on the surface of the bamboo aggregate are repeatedly covered with sand. The sand covers no less than 3 / 5 of the surface area of ​​the bamboo aggregate.

[0009] 3) Drying bamboo aggregate: After surface treatment, the moistened bamboo aggregate is poured out and laid flat on the grid board. Multiple grids are set on the top surface of the grid board, and each grid can only hold one piece of bamboo aggregate to ensure the separation of bamboo aggregates and avoid dense accumulation of bamboo aggregates. The drying treatment of wet bamboo aggregates includes placing them in a well-ventilated environment to air dry naturally for 2 to 5 days, using a cold air blower or air drying room at a low temperature for more than 24 hours, using an oven or hot air gun at a high temperature of 100℃ to 200℃ for 6 to 12 hours, or using ultraviolet lamps for more than 24 hours.

[0010] 4) Bamboo aggregate concrete mix: Bamboo aggregate concrete includes the following raw materials by weight: 400-530 parts of cementitious materials, 660-820 parts of fine aggregate, 0-1100 parts of inorganic coarse aggregate, 20-600 parts of bamboo aggregate, 180-200 parts of water, and 8-10 parts of water-reducing agent.

[0011] 5) Mixing bamboo aggregate concrete: Add the water-reducing agent to the mixing water and stir evenly. Before mixing the concrete, wet the mixer, then add the cementitious materials, inorganic coarse aggregate, and fine aggregate and dry mix for 2 to 10 minutes. Add 30% to 60% of the total mixing water and stir for 2 to 10 minutes, then pause for 2 to 10 minutes. Then add the remaining mixing water and evenly add the bamboo aggregate and stir for 5 to 15 minutes. Finally, pour the mixed bamboo aggregate concrete into the mold. To reduce the risk of segregation of the bamboo aggregate, vibrate the bamboo aggregate concrete in layers, with each layer not exceeding 25 cm in thickness.

[0012] 6) Demolding: When the average temperature of bamboo aggregate concrete is above 25℃, the demolding time shall not exceed 24 hours; when the average temperature is below 25℃, the demolding time shall be 2 to 7 days.

[0013] 7) Curing bamboo aggregate concrete: Before demolding, cover the surface of bamboo aggregate concrete with a curing film, spray or water to keep it moist, and after demolding, place the bamboo aggregate concrete in water for curing for no less than 7 days.

[0014] The bamboo aggregate substitution method is either continuous gradation substitution or single-particle gradation substitution.

[0015] The inorganic coarse aggregate is one of crushed stone, pebbles, or ceramsite, with a nominal particle size of 5mm to 40mm. The cementitious material is one of ordinary cement, silicate cement, magnesium cement, aluminate cement, slag cement, or fly ash cement. The fine aggregate is one of natural sand or artificial sand, with a particle size of less than 4.75mm.

[0016] When the surface of the bamboo aggregate is pre-coated with cement slurry, pre-coated with adhesive, or bonded with sand, the cement is one of ordinary cement, silicate cement, magnesium cement, aluminate cement, slag cement, and fly ash cement; the adhesive is one of epoxy resin, epoxy mortar, phenolic resin, and polyurethane resin; and the sand is one of river sand, sea sand, quartz sand, and corundum.

[0017] The beneficial effects of this invention are as follows:

[0018] 1) The surface-treated bamboo aggregate has significantly improved waterproof and anti-corrosion properties as well as mechanical properties, and its surface roughness is increased, resulting in better adhesion to cement. This makes the bamboo aggregate concrete more workable and reduces slump loss.

[0019] 2) The concrete prepared by this mixing method fully utilizes the advantages of bamboo aggregate, such as high compressive strength, high strength-to-weight ratio, and low density, resulting in bamboo aggregate concrete with light weight, high strength, and good deformation capacity, thus forming a de facto ultra-lightweight and high-ductility concrete.

[0020] 3) Bamboo is sourced from nature, is easy to process, and has a low cost. This mixing and processing method uses renewable and sustainable bamboo as a building material, which can solve the problems of existing building raw material shortages and environmental damage, while vigorously promoting the development of green buildings and sustainable building materials. Detailed Implementation

[0021] The present invention will be further described below with reference to specific embodiments. A method for mixing and processing bamboo aggregate concrete, characterized in that its construction steps are as follows:

[0022] 1) Cutting bamboo ribs: Select bamboo that is over 3 years old and has no obvious diseases, pests and damage. Remove the green and yellow parts of the bamboo. Break the hollow round bamboo tubes or split the hollow round bamboo tubes into bamboo strips and then tie multiple bamboo strips together and cut them into new block bamboo ribs. The length-to-diameter ratio of the bamboo ribs is 1 to 3 and the size is 2mm to 30mm.

[0023] 2) Surface Treatment of Bamboo Frames: A method involving pre-coating with cement slurry, applying adhesive, and bonding sand is used to treat the surface of the bamboo frames. Before surface treatment, contaminants are removed to ensure a smooth and clean surface. For pre-coating with cement slurry, cement and bamboo frames are added to a container in batches and mixed. Then, a predetermined amount of water is added, with a water-cement ratio of 0.4–0.6. Simultaneously, an adhesive with a ratio of 1:10 to 1:5 to the cement slurry is added and mixed for 5–15 minutes to enhance the bond between the cement slurry and the bamboo frames. For applying adhesive, the adhesive is pre-mixed and then applied in one layer to the surface of the bamboo frames. The application method is as follows: This includes brushing, rolling, and spraying. After the bamboo aggregate is pre-coated with cement slurry and adhesive, it is left to stand indoors for 24 hours. The coverage of the cement slurry or adhesive is then checked, and touch-ups are made to ensure that the surface of the bamboo aggregate is completely covered by the cement slurry or adhesive and that the cement slurry or adhesive does not flow naturally. The total coating thickness of the cement slurry or adhesive is 0.05mm to 1.0mm. When applying sand, a layer of sand is evenly sprinkled on the surface of the wet bamboo aggregate after the adhesive has been applied. The sand is densely distributed on the surface of the bamboo aggregate. Areas with large gaps on the surface of the bamboo aggregate are repeatedly covered with sand. The sand covers no less than 3 / 5 of the surface area of ​​the bamboo aggregate.

[0024] 3) Drying bamboo aggregate: After surface treatment, the moistened bamboo aggregate is poured out and laid flat on the grid board. Multiple grids are set on the top surface of the grid board, and each grid can only hold one piece of bamboo aggregate to ensure the separation of bamboo aggregates and avoid dense accumulation of bamboo aggregates. The drying treatment of wet bamboo aggregates includes placing them in a well-ventilated environment to air dry naturally for 2 to 5 days, using a cold air blower or air drying room at a low temperature for more than 24 hours, using an oven or hot air gun at a high temperature of 100℃ to 200℃ for 6 to 12 hours, or using ultraviolet lamps for more than 24 hours.

[0025] 4) Bamboo aggregate concrete mix: Bamboo aggregate concrete includes the following raw materials by weight: 400-530 parts of cementitious materials, 660-820 parts of fine aggregate, 0-1100 parts of inorganic coarse aggregate, 20-600 parts of bamboo aggregate, 180-200 parts of water, and 8-10 parts of water-reducing agent.

[0026] 5) Mixing bamboo aggregate concrete: Add the water-reducing agent to the mixing water and stir evenly. Before mixing the concrete, wet the mixer, then add the cementitious materials, inorganic coarse aggregate, and fine aggregate and dry mix for 2 to 10 minutes. Add 30% to 60% of the total mixing water and stir for 2 to 10 minutes, then pause for 2 to 10 minutes. Then add the remaining mixing water and evenly add the bamboo aggregate and stir for 5 to 15 minutes. Finally, pour the mixed bamboo aggregate concrete into the mold. To reduce the risk of segregation of the bamboo aggregate, vibrate the bamboo aggregate concrete in layers, with each layer not exceeding 25 cm in thickness.

[0027] 6) Demolding: When the average temperature of bamboo aggregate concrete is above 25℃, the demolding time shall not exceed 24 hours; when the average temperature is below 25℃, the demolding time shall be 2 to 7 days.

[0028] 7) Curing bamboo aggregate concrete: Before demolding, cover the surface of bamboo aggregate concrete with a curing film, spray or water to keep it moist, and after demolding, place the bamboo aggregate concrete in water for curing for no less than 7 days.

[0029] The bamboo aggregate substitution method is one of continuous graded substitution and single-particle-grade substitution.

[0030] Inorganic coarse aggregate is one of crushed stone, pebbles, or ceramsite, with a nominal particle size of 5mm to 40mm; cementitious material is one of ordinary cement, silicate cement, magnesium acid cement, aluminate cement, slag cement, or fly ash cement; fine aggregate is one of natural sand or artificial sand, with a particle size of less than 4.75mm.

[0031] When the surface of bamboo aggregate is pre-coated with cement slurry, adhesive, or sand, the cement is one of ordinary cement, silicate cement, magnesium cement, aluminate cement, slag cement, or fly ash cement; the adhesive is one of epoxy resin, epoxy mortar, phenolic resin, or polyurethane resin; and the sand is one of river sand, sea sand, quartz sand, or corundum. Specific Implementation Example 1:

[0033] Hollow bamboo tubes from Anji County, Zhejiang Province, were split into strips, and the outer green and inner yellow layers of the bamboo were sanded off. These strips were then cut into bamboo blocks with widths of 6mm, 9mm, and 12mm and a uniform thickness of 7mm using a saw. These were the untreated bamboo aggregates. To improve the physical and mechanical properties of the bamboo aggregates, polyurethane and epoxy mortar were applied as surface treatments. The polyurethane or epoxy mortar was pre-mixed and then applied as a pre-coat layer to the bamboo aggregate surface. After standing indoors for 24 hours, the coverage of the polyurethane or epoxy mortar was checked, and multiple coats were applied to ensure complete coverage without any flow. The total coating thickness of the polyurethane or epoxy mortar ranged from 0.2mm to 1.0mm. The physical and mechanical properties of the untreated, polyurethane-coated, and epoxy-coated bamboo aggregates showed significant differences. The basic densities of the untreated, polyurethane-coated, and epoxy-coated bamboo aggregates were approximately 400 kg / m³, respectively. 3 509kg / m 3 732kg / m 3The water absorption rate of bamboo aggregate is 1 / 3 to 1 / 8 that of gravel aggregate, reflecting the lightweight advantage of bamboo aggregate. The water absorption rate of untreated bamboo aggregate is 169%, which is 4.5 times and 15.4 times higher than that of polyurethane-coated bamboo aggregate (38%) and epoxy-coated bamboo aggregate (3.7%), respectively. The volumetric expansion and contraction coefficient of epoxy-coated bamboo aggregate is 22.7% higher than that of polyurethane-coated bamboo aggregate, indicating that epoxy mortar can effectively improve the dimensional stability of bamboo aggregate. The average compressive strength of epoxy-coated bamboo aggregate is 46.9 MPa, which is 28.8% and 15.8% higher than that of untreated and polyurethane-coated bamboo aggregate, respectively, indicating that epoxy mortar can improve the compressive performance of bamboo aggregate.

Claims

1. A method for mixing and processing bamboo aggregate concrete, characterized in that, The construction steps are as follows: 1) Cutting bamboo ribs: Select bamboo that is over 3 years old and has no obvious diseases, pests and damage. Remove the green and yellow parts of the bamboo. Break the hollow round bamboo tubes or split the hollow round bamboo tubes into bamboo strips and then tie multiple bamboo strips together and cut them into block bamboo ribs. The length-to-diameter ratio of the bamboo ribs is 1 to 3 and the size is 2mm to 30mm. 2) Surface Treatment of Bamboo Frames: Bamboo frames are surface-treated using either pre-coating with cement slurry or applying adhesive. Before surface treatment, contaminants are removed to ensure a smooth and clean surface. For pre-coating with cement slurry, cement and bamboo frames are added to a container in batches and mixed. Then, a predetermined amount of water is added, with a water-cement ratio of 0.4–0.

6. Simultaneously, an adhesive with a ratio of 1:10–1:5 to the cement slurry is added and mixed for 5–15 minutes to enhance the bond between the cement slurry and the bamboo frames. For applying adhesive, the adhesive is pre-mixed and then applied in one layer to the surface of the bamboo frames. The application method is as follows: This includes brushing, rolling, and spraying. After the bamboo aggregate is pre-coated with cement slurry or adhesive, it is left to stand indoors for 24 hours. The coverage of the cement slurry or adhesive is then checked, and touch-ups are made to ensure that the surface of the bamboo aggregate is completely covered by the cement slurry or adhesive and that the cement slurry or adhesive does not flow naturally. The total coating thickness of the cement slurry or adhesive is 0.05mm to 1.0mm. When applying sand, a layer of sand is evenly sprinkled on the surface of the wet bamboo aggregate after the adhesive has been applied. The sand is densely distributed on the surface of the bamboo aggregate, and the gaps on the surface of the bamboo aggregate are filled multiple times. The sand covers no less than 3 / 5 of the surface area of ​​the bamboo aggregate. 3) Drying bamboo aggregate: After surface treatment, the moistened bamboo aggregate is poured out and laid flat on the grid board. Multiple grids are set on the top surface of the grid board, and each grid can only hold one piece of bamboo aggregate to ensure the separation of bamboo aggregates and avoid dense accumulation of bamboo aggregates. The drying treatment of wet bamboo aggregates includes one of the following: placing it in a well-ventilated environment to air dry naturally for 2 to 5 days, using a cold air blower or a drying room at a low temperature for more than 24 hours, using an oven or hot air gun at a high temperature of 100℃ to 200℃ for 6 to 12 hours, or using an ultraviolet lamp for more than 24 hours. 4) Bamboo aggregate concrete mix: Bamboo aggregate concrete includes the following raw materials by weight: 400-530 parts of cementitious materials, 660-820 parts of fine aggregate, 0-1100 parts of inorganic coarse aggregate, 20-600 parts of bamboo aggregate, 180-200 parts of water, and 8-10 parts of water-reducing agent. 5) Mixing bamboo aggregate concrete: Add the water-reducing agent to the mixing water and stir evenly. Before mixing the concrete, wet the mixer, then add the cementitious materials, inorganic coarse aggregate, and fine aggregate and dry mix for 2 to 10 minutes. Add 30% to 60% of the total mixing water and stir for 2 to 10 minutes, then pause for 2 to 10 minutes. Then add the remaining mixing water and evenly add the bamboo aggregate and stir for 5 to 15 minutes. Finally, pour the mixed bamboo aggregate concrete into the mold. To reduce the risk of segregation of the bamboo aggregate, vibrate the bamboo aggregate concrete in layers, with each layer not exceeding 25 cm in thickness. 6) Demolding: When the average temperature of bamboo aggregate concrete is above 25℃, the demolding time shall not exceed 24 hours; when the average temperature is below 25℃, the demolding time shall be 2 to 7 days. 7) Curing bamboo aggregate concrete: Before demolding, cover the surface of bamboo aggregate concrete with a curing film, spray or water to keep it moist, and after demolding, place the bamboo aggregate concrete in water for curing for no less than 7 days.

2. The method for mixing and processing bamboo aggregate concrete as described in claim 1, characterized in that... The bamboo aggregate substitution method is either continuous gradation substitution or single-particle gradation substitution.

3. The method for mixing and processing bamboo aggregate concrete as described in claim 1, characterized in that... The inorganic coarse aggregate is one of crushed stone, pebbles, or ceramsite, with a nominal particle size of 5mm to 40mm; the cementing material is one of ordinary cement, silicate cement, magnesium cement, aluminate cement, slag cement, or fly ash cement; and the fine aggregate is one of natural sand or artificial sand, with a particle size of less than 4.75mm.

4. The method for mixing and processing bamboo aggregate concrete as described in claim 1, characterized in that... When the surface of the bamboo aggregate is pre-coated with cement slurry or coated with adhesive, the cement is one of ordinary cement, silicate cement, magnesium cement, aluminate cement, slag cement, and fly ash cement; the adhesive is one of epoxy resin, epoxy mortar, phenolic resin, and polyurethane resin; and the sand is one of river sand, sea sand, quartz sand, and corundum.