Requirements and construction technology of pervious concrete base


Release time:

2016-02-26

Author:

Shandong Xindadi Group

Source:

Requirements and construction technology of pervious concrete base

Requirements for pervious concrete pavement and base course

(1) the thickness of permeable concrete pavement: because the color permeable concrete is mostly used in sidewalks, squares, parking lots, garden trails and other places. The thickness of the panel varies depending on the application of the pavement. For light-load floors such as sidewalks and bicycle lanes, the thickness of the surface layer is generally not less than 8cm; For medium-load floors such as parking lots and squares, the thickness of the surface layer is not less than 10cm. Considering the cost, the surface layer can be divided into two layers, I .e. the surface layer is a colored permeable concrete layer, the thickness is generally not less than 3cm, and the lower layer is a plain permeable concrete layer.

(2) In order to ensure that the structural layer of the road body has sufficient overall strength and water permeability, a permeable base layer and a cushion layer with better water retention are required under the surface layer.

Base requirements: in the solid soil layer compaction layer, with the use of base materials, should have appropriate strength, must have a good permeability, the use of graded gravel or graded gravel. When graded crushed stone is used, the maximum particle size of the crushed stone shall be less than 0.7 times the thickness of the base course and not more than 50mm. Cushion generally uses natural gravel, particle size is less than 10mm, commonly known as melon seed pieces, and paved with a certain thickness, laying to be uniform and smooth.

(3) Considering the seasonal factors of heavy rainstorm, in order to prevent excessive water accumulation at the base and affect the foundation, special permeable pipeline drainage is set at the base, leading to the drainage system beside the road, and excessive rainwater is removed in time.

Construction of color permeable concrete

Generally, 8cm is the standard as the benchmark thickness of the sidewalk, and on this basis, different thicknesses are designed according to different functions. To reduce costs, a layered design can be used.

For the construction of the above-mentioned single-layer or layered permeable concrete pavement, the key construction technology is the guarantee of the quality of the permeable concrete pavement. The specific construction plan is as follows.

1 Preparation before construction (three major preparations such as organization, material and technology should be made before construction)

(1) Organizational preparation: establish and improve the personnel setting of the construction project organization, take the realization of the work tasks required by the construction project as the principle, strictly control the staffing, and strive to be multi-functional and multi-functional.

(2) Material preparation: Permeable concrete is essentially similar to cement concrete construction, with only less sand in its raw materials, while high-grained gravel with a certain particle size replaces aggregate, and has a certain amount of material (cementing material) in construction.

Material preparation should be on-site preparation, such as personnel accommodation, required water and electricity supply, construction of engineering material stacking sheds (sheds with waterproof measures required for cementing materials); A series of preparatory work such as the installation site of mixing machinery.

Mixing machinery setting site, permeable concrete mixing is the use of small horizontal mixer. The best setting scheme of the mixer is the middle section of the construction site. Because the permeable concrete is a dry material concrete, its initial setting is fast, and the transportation time should be as short as possible. In order to prevent the concrete from sticking to the construction site, a certain range of the lower part of the mixer needs to be fortified with protective plates.

(3) Construction machinery, carts, bricklayer tools and other necessary tools, wood or steel for formwork erection, etc.; water and electricity facilities in place, domestic water, electricity and construction water and electricity. Construction electricity: three-phase electricity, construction water: ordinary tap water connected to the mixing equipment.

(4) Technical preparation before construction: understand and analyze the characteristics and progress requirements of the project, understand the objective conditions of construction, be familiar with the design drawings according to the design requirements, reasonably arrange the construction force, formulate the construction plan, and make technical preparations for the smooth completion of the project.

(5) Cooperate with the civil engineering team of the foundation party to lay special permeable pipes while making the ground base. In addition to laying according to the requirements of the drawings, the permeable pipes must be connected with the original road drainage system and become a part of the road drainage system.

2 Construction process: personnel and equipment can enter the site for construction only on the basis of sufficient preparation.

(1) formwork erection: construction personnel shall first separate formwork erection and regional formwork erection according to design requirements, and attention shall be paid to the problems of height, verticality, flood slope, etc. during formwork erection.

(2) Mixing: Agitator: According to the amount of work, mechanical agitators with different capacities shall be configured. On the ground within a certain range of mechanical agitators, material receiving equipment (such as square plate type bucket) to prevent water and materials from being scattered shall be set up to protect the sanitation of the construction environment and reduce the cleaning work after construction.

Permeable concrete cannot be mixed manually. Ordinary concrete mixing machinery is used for mixing. First, cement and adhesive materials are mixed for 1-2 minutes, then crushed stone is poured into the mixture for about 1-2 minutes, and then the specified amount of water is added for 2-3 times to continue mixing for about 1-2 minutes. Depending on the degree of mixing uniformity, the mechanical mixing time can be appropriately extended, but it is not suitable for mixing for a long time. Holding the mixing material in your hand will not cause water loss, viscosity or initial formation, and the amount of water should not be too much or too little.

The mixed slurry is tiled into the feeling tool with a scraper or scraping ruler, rolled and paved with a roller, and the vibrator is eliminated. The permeable concrete cannot be compacted out of the slurry, and if the slurry is blocked out, the particle hole cannot be permeated.

Key words: