I. Introduction Colored pervious concrete is a kind of porous lightweight concrete made of gravel, cement, binder, pigment and water. It contains no fine aggregate and is coated with a thin layer of cement from the surface of coarse aggregate. Pulps have a honeycomb structure in which pores are evenly distributed, and therefore have the characteristics of air permeability, water permeability, and light weight. As the environmental load-reducing concrete, the research and development of pervious concrete has received increasing attention.
Pervious concrete has different characteristics from ordinary concrete: small capacity, insignificant water capillary phenomenon, high water permeability, small amount of cement, simple construction, etc. Therefore, the advantages of this new type of building material are continuously known, and The road area is gradually applied. It can increase the infiltration of rainwater into the ground and alleviate some of the urban environmental problems such as the sharp drop in the city's groundwater level.
Second, colored permeable concrete
1, material composition:
Pervious concrete binder ------ It is mainly composed of strengthening agent, flow agent, stabilizer and fiber. It is blended with aggregates, cement, pigments, etc., and can greatly increase the strength of the permeable concrete after stirring. At the same time enhance the stability and fluidity of permeable concrete, so that the permeability of water better.
(1) Gravel: There are also certain requirements for gravel particles, which are divided into 1#, 2#, and 3#, depending on the particle size range. The specific particle range is as follows:
Gravel semicolon 1# 2# 3#
Particle size range (mm) 2.4~4.75 4.75~9.5 9.6~13.2
Gravel is one of the main materials of permeable concrete and its quality must be well controlled.
(2) Water: Normal tap water can be used. Normally unfiltered muddy groundwater or used dirty water cannot be used.
(3) Cement: 42.5 Portland cement can be used.
(4) Pigments: High-quality inorganic pigments.
2. Types of colored permeable concrete (1) Plain permeable concrete: It is a pervious concrete with ordinary cement color.
(2) Color pervious concrete: pervious concrete composed of common cement mixed with inorganic pigments.
(3) Pervious concrete with a combination of compression moulding process: a floor composed of a colored concrete stamping process and a pervious concrete.
The above-mentioned various types of pervious concrete technology are designed and applied according to different locations, environments, bearing requirements and basic conditions of the project, and have more practicality and applicability in pattern changes and color changes. .
Third, the pervious concrete pavement base requirements
1, the thickness of pervious concrete pavement: from the above we can see the reasons for the strength of colored pervious concrete, mostly used in sidewalks, squares, parking lots, garden trails, residential roads and other places. According to the different applications of the pavement, the thickness of the surface layer is different.
For pavements with light loads such as sidewalks and bicycle lanes, the thickness of pervious concrete is generally not less than 8 ;. For permeable floors such as parking lots and plazas, the thickness of pervious concrete shall not be less than 10 。.
2. In order to ensure that the pavement body structure layer has sufficient overall strength and water permeability, a water-permeable base layer and a good water-retaining cushion layer are required under the surface layer.
Grass-roots requirements: on the compacted layer of prime soil, the basic materials used should have appropriate strength, and must have good water permeability, using graded gravel or graded gravel. When using a graded gravel, the maximum particle size of the gravel should be less than 0.7 times the thickness of the base layer and not exceed 50 mm.
The cushion is generally made of natural gravel. The particle size is less than 10mm, commonly known as melon seeds, and the thickness is 15cm~30cm. The laying needs to be even and smooth.
4. The construction of colored permeable concrete is generally based on 8cm as the reference thickness of the sidewalk. Based on this, different thicknesses are designed according to different functions.
1. Pre-construction preparation: Before the construction, three preparations, including personnel, material and technology, should be done.
(1) Personnel preparation: Establishing a sound personnel structure for the construction project organization, based on the principle of fulfilling the work tasks required by the construction project, and the personnel allocation should be strictly controlled.
(2) Material preparation: Pervious concrete is similar to ordinary concrete, and there is less sand in the raw material, and a certain size of gravel replaces the aggregate, and there is a certain amount of material (binder, gravel) in the construction. Material preparation should be site preparations, such as personnel accommodation, required water, electricity supply, engineering materials stacking shed (bonding materials need to have waterproof measures) to build; a set of stirring machinery site and other preparations.
(3) Essential tools such as construction machinery, carts, bricklayer tools, etc.; hydroelectric facilities are in place, domestic water, electricity, and construction hydropower. Electricity for construction: Three-phase electricity, construction water: Common tap water is connected to the mixing equipment.
(4) Pre-construction technical preparation: Understand and analyze the characteristics and progress requirements of the project, understand the objective conditions of the construction, familiarize with the design drawings according to the design requirements, reasonably arrange the construction strength, work out the construction plan, and do a good job for the successful completion of the project On the preparations.
2. Construction: On the basis of sufficient preparation work, personnel and equipment can enter the site for construction. (See Annex II)
(1) Stirring permeable concrete mixture has a large consistency and a small quantity. In order to ensure that the slurry can be uniformly wrapped on the aggregate, a forced mixer should be adopted, and the mixing time is longer than that of conventional concrete. The permeable concrete mixture is relatively hard. Before pouring, the roadbed must be wetted with water. The reason is that the amount of stirring water in the permeable concrete is limited. If the roadbed material absorbs some of the mixing water, it will accelerate the condensation of the cement. The time of pouring, vibrating, compacting and seaming on the road, and the rapid loss of water will weaken the bond strength between the aggregates.
Precautions:
1) The person on the construction site must be responsible for the material ratio.
2) Strictly control the water-cement ratio, that is, control the amount of water added. Water is added 2 to 3 times during agitation, and it is not allowed to add it once.
3) In order to stir the material evenly, extend the mechanical stirring time properly, but it should not be too long.
(2) Transport Permeable concrete is a dry concrete material, which is initially set quickly. Generally, the transport time of the mixture is controlled according to climatic conditions. Transportation is generally controlled within 15 minutes. Do not stop during transport and the cart must be stable.
(3) The paving and forming permeable concrete belongs to the dry concrete material, the initial setting is fast, and the paving must be timely. For sidewalks, a large area of ​​construction is paved in a separate way, with a loosening coefficient of 1.1. Spread the mixture evenly on the work surface, use a scraping ruler to find out the flatness and control a certain degree of flooding. Finally, use a spatula to smooth the surface.
Precautions:
1) Loose paving coefficient is the ratio of material paving height to actual height. According to the dry humidity of pervious concrete, it is generally between 1.1 and 1.5.
2) Be as quick and correct as possible when paving.
3) Because of the large porosity of pervious concrete, the water disperses quickly. When the weather temperature is higher than 35°C, construction time should be avoided at noon and it is suitable for construction in the morning and at night.
(4) Maintenance Permeable concrete is similar to cement concrete in terms of properties. Water conservation will be carried out the next day after the construction is completed. If the weather is dry and hot, it can be sprinkling water for 8 hours after pouring, and at least 2 times per day, and the curing time should be no less than 3 days. However, when pouring water, it is not appropriate to use pressure water and water to directly shower the concrete surface. Drench the water directly from above.
3, brushing transparent brightener:
After about 3 days of molding the surface concrete, a transparent brightener is applied or sprayed to enhance durability and aesthetics. To prevent it from being used for a long time causes the pores of the permeable concrete to become contaminated and blocked.
The construction process is as follows:
Material preparation, mixing, transport, unloading, paving, leveling, compaction, receiving, curing, cutting, cutting and painting, brightening agent. Fifth, quality assurance and maintenance services. Our company's construction floor for three years of free maintenance (except for man-made damage). After the maintenance period, the company will provide long-term after-sales services for the manufacturers by collecting the cost of the materials.
Pervious concrete has different characteristics from ordinary concrete: small capacity, insignificant water capillary phenomenon, high water permeability, small amount of cement, simple construction, etc. Therefore, the advantages of this new type of building material are continuously known, and The road area is gradually applied. It can increase the infiltration of rainwater into the ground and alleviate some of the urban environmental problems such as the sharp drop in the city's groundwater level.
Second, colored permeable concrete
1, material composition:
Pervious concrete binder ------ It is mainly composed of strengthening agent, flow agent, stabilizer and fiber. It is blended with aggregates, cement, pigments, etc., and can greatly increase the strength of the permeable concrete after stirring. At the same time enhance the stability and fluidity of permeable concrete, so that the permeability of water better.
(1) Gravel: There are also certain requirements for gravel particles, which are divided into 1#, 2#, and 3#, depending on the particle size range. The specific particle range is as follows:
Gravel semicolon 1# 2# 3#
Particle size range (mm) 2.4~4.75 4.75~9.5 9.6~13.2
Gravel is one of the main materials of permeable concrete and its quality must be well controlled.
(2) Water: Normal tap water can be used. Normally unfiltered muddy groundwater or used dirty water cannot be used.
(3) Cement: 42.5 Portland cement can be used.
(4) Pigments: High-quality inorganic pigments.
2. Types of colored permeable concrete (1) Plain permeable concrete: It is a pervious concrete with ordinary cement color.
(2) Color pervious concrete: pervious concrete composed of common cement mixed with inorganic pigments.
(3) Pervious concrete with a combination of compression moulding process: a floor composed of a colored concrete stamping process and a pervious concrete.
The above-mentioned various types of pervious concrete technology are designed and applied according to different locations, environments, bearing requirements and basic conditions of the project, and have more practicality and applicability in pattern changes and color changes. .
Third, the pervious concrete pavement base requirements
1, the thickness of pervious concrete pavement: from the above we can see the reasons for the strength of colored pervious concrete, mostly used in sidewalks, squares, parking lots, garden trails, residential roads and other places. According to the different applications of the pavement, the thickness of the surface layer is different.
For pavements with light loads such as sidewalks and bicycle lanes, the thickness of pervious concrete is generally not less than 8 ;. For permeable floors such as parking lots and plazas, the thickness of pervious concrete shall not be less than 10 。.
2. In order to ensure that the pavement body structure layer has sufficient overall strength and water permeability, a water-permeable base layer and a good water-retaining cushion layer are required under the surface layer.
Grass-roots requirements: on the compacted layer of prime soil, the basic materials used should have appropriate strength, and must have good water permeability, using graded gravel or graded gravel. When using a graded gravel, the maximum particle size of the gravel should be less than 0.7 times the thickness of the base layer and not exceed 50 mm.
The cushion is generally made of natural gravel. The particle size is less than 10mm, commonly known as melon seeds, and the thickness is 15cm~30cm. The laying needs to be even and smooth.
4. The construction of colored permeable concrete is generally based on 8cm as the reference thickness of the sidewalk. Based on this, different thicknesses are designed according to different functions.
1. Pre-construction preparation: Before the construction, three preparations, including personnel, material and technology, should be done.
(1) Personnel preparation: Establishing a sound personnel structure for the construction project organization, based on the principle of fulfilling the work tasks required by the construction project, and the personnel allocation should be strictly controlled.
(2) Material preparation: Pervious concrete is similar to ordinary concrete, and there is less sand in the raw material, and a certain size of gravel replaces the aggregate, and there is a certain amount of material (binder, gravel) in the construction. Material preparation should be site preparations, such as personnel accommodation, required water, electricity supply, engineering materials stacking shed (bonding materials need to have waterproof measures) to build; a set of stirring machinery site and other preparations.
(3) Essential tools such as construction machinery, carts, bricklayer tools, etc.; hydroelectric facilities are in place, domestic water, electricity, and construction hydropower. Electricity for construction: Three-phase electricity, construction water: Common tap water is connected to the mixing equipment.
(4) Pre-construction technical preparation: Understand and analyze the characteristics and progress requirements of the project, understand the objective conditions of the construction, familiarize with the design drawings according to the design requirements, reasonably arrange the construction strength, work out the construction plan, and do a good job for the successful completion of the project On the preparations.
2. Construction: On the basis of sufficient preparation work, personnel and equipment can enter the site for construction. (See Annex II)
(1) Stirring permeable concrete mixture has a large consistency and a small quantity. In order to ensure that the slurry can be uniformly wrapped on the aggregate, a forced mixer should be adopted, and the mixing time is longer than that of conventional concrete. The permeable concrete mixture is relatively hard. Before pouring, the roadbed must be wetted with water. The reason is that the amount of stirring water in the permeable concrete is limited. If the roadbed material absorbs some of the mixing water, it will accelerate the condensation of the cement. The time of pouring, vibrating, compacting and seaming on the road, and the rapid loss of water will weaken the bond strength between the aggregates.
Precautions:
1) The person on the construction site must be responsible for the material ratio.
2) Strictly control the water-cement ratio, that is, control the amount of water added. Water is added 2 to 3 times during agitation, and it is not allowed to add it once.
3) In order to stir the material evenly, extend the mechanical stirring time properly, but it should not be too long.
(2) Transport Permeable concrete is a dry concrete material, which is initially set quickly. Generally, the transport time of the mixture is controlled according to climatic conditions. Transportation is generally controlled within 15 minutes. Do not stop during transport and the cart must be stable.
(3) The paving and forming permeable concrete belongs to the dry concrete material, the initial setting is fast, and the paving must be timely. For sidewalks, a large area of ​​construction is paved in a separate way, with a loosening coefficient of 1.1. Spread the mixture evenly on the work surface, use a scraping ruler to find out the flatness and control a certain degree of flooding. Finally, use a spatula to smooth the surface.
Precautions:
1) Loose paving coefficient is the ratio of material paving height to actual height. According to the dry humidity of pervious concrete, it is generally between 1.1 and 1.5.
2) Be as quick and correct as possible when paving.
3) Because of the large porosity of pervious concrete, the water disperses quickly. When the weather temperature is higher than 35°C, construction time should be avoided at noon and it is suitable for construction in the morning and at night.
(4) Maintenance Permeable concrete is similar to cement concrete in terms of properties. Water conservation will be carried out the next day after the construction is completed. If the weather is dry and hot, it can be sprinkling water for 8 hours after pouring, and at least 2 times per day, and the curing time should be no less than 3 days. However, when pouring water, it is not appropriate to use pressure water and water to directly shower the concrete surface. Drench the water directly from above.
3, brushing transparent brightener:
After about 3 days of molding the surface concrete, a transparent brightener is applied or sprayed to enhance durability and aesthetics. To prevent it from being used for a long time causes the pores of the permeable concrete to become contaminated and blocked.
The construction process is as follows:
Material preparation, mixing, transport, unloading, paving, leveling, compaction, receiving, curing, cutting, cutting and painting, brightening agent. Fifth, quality assurance and maintenance services. Our company's construction floor for three years of free maintenance (except for man-made damage). After the maintenance period, the company will provide long-term after-sales services for the manufacturers by collecting the cost of the materials.
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