JPH0215504B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a pavement construction method for forming pavements that have good water permeability and are suitable for roads, parks, grounds, sports facilities such as tennis courts, etc.

[Conventional technology]

Conventional pavement can be said to be a type of impermeable layer provided on the ground surface, with the exception of some special cases.

However, recently, the importance of permeable pavement has been emphasized. In particular, by ensuring the permeability of road surfaces, etc., it is possible to reduce the amount of drainage from the road surface, eliminating the need for excessively large drainage facilities, and increasing the amount of underground water stored by returning rainwater to the ground. It has many advantages, such as a significant improvement in vegetation and other ecological changes, and also eliminates water splashing on the road surface and increases slip resistance, making it possible to walk comfortably even during rainy days. There was a strong need for improvements to the pavement that would bring about better results.

[Problem that the invention seeks to solve]

The present invention was made in view of the actual situation described above,
In order to significantly improve the water permeability of pavement, a mixture made by mixing additives mainly composed of various inorganic salts with pulverized granulated slag aggregate produces extremely good water permeability of pavement. To provide an epoch-making pavement construction method for forming a pavement in which the compressive, bending, tensile, etc. strengths of the completed pavement are significantly increased, and the elasticity of the road surface is significantly improved. Its purpose is to

[Means for solving problems]

The present invention provides an additive mainly composed of inorganic salts,
The main material is granulated slag, which has self-hardening properties, and if necessary, Portland cement is added to promote an increase in the strength of the pavement base to form a mixture. After this mixture is laid, the surface delamination resistance of the pavement is reduced. This relates to a method of completing permeable pavement by spraying and impregnating a binder to integrate the upper and lower layers, and its gist is as follows: a. 20 to 30 weight of sodium chloride per granulated slag; parts by weight of magnesium chloride, 20 to 30 parts by weight of potassium chloride, 5 to 15 parts by weight of calcium chloride, and 4 to 8 parts by weight of citric acid. (b) A pavement construction method in which c) a pavement is formed with water permeability by laying on a leveled roadbed, and further, as an embodiment thereof, (d) approximately 1 kg of the additive is added to 1 m ³ of granulated slag in an aqueous solution. (e) Portland cement is mixed in the mixture in an amount of 16% by weight or less based on the mixture; (f) A binder is sprinkled on the surface of the laid mixture.

Hereinafter, the present invention will be described based on examples with reference to flowcharts.

〔Example〕

First, the granulated slag used in the present invention contains lime (CaO), silicic acid (SiO ₂ ), alumina (Al ₂ O ₃ ), magnesia (MgO), and other oxides of manganese, iron, titanium, etc. It is produced by water-cooling and pulverizing a molten product made by reacting some components of iron ore, coke, limestone, etc. in a steelmaking blast furnace (generally called a blast furnace). An example _of its _components is: CaO41.0SiO2 _{33.4Al2O314.5MgO6.0Others5.1Total} 100 (parts by weight). This product contains 10 to 30% natural water based on the solid material having the above composition.

Additives mainly composed of inorganic salts that are added to the granulated granulated slag that becomes the aggregate include NaCl, MgCl ₂ ,
Consisting of KCl, _CaCl2 and citric acid, NaCl20~30
parts by weight, 20-30 parts by weight of MgCl ₂ , 35-45 parts by weight of KCl, 5-15 parts by weight of CaCl ₂ and 4-8 parts by weight of citric acid. When the solid content of the agent is 100 parts by weight,
Each salt etc. contains 25 parts by weight of NaCl, 21 parts by weight of _MgCl2 ,
40 parts by weight of KCl, 8 parts by weight of CaCl ₂ and 6 parts by weight of citric acid are used. This additive is added to the granulated slag in an aqueous solution containing about 8 times as much water.

In this method, approximately 1 ^m3 of granulated slag
A mixture is used in which Kg of additives are added and mixed in a soil mixer. The mixture has self-hardening properties.

In the method of the invention, the required amount of Portland cement is added to the mixture to increase the strength of the pavement substrate. The cement components used are, for example, SiO ₂ 22.0 Al ₂ O ₃ 5.5 CaO 65.0 other oxides etc. 5.4 and 3.0% by weight each.

Furthermore, the binder used in the construction method of the present invention is preferably impregnated into the surface after being laid and pressurized, so that the upper and lower layers are integrated to ensure the peeling resistance of the surface. The water permeability of the pavement will not be affected by the application of the binder.

Next, one example of a pavement achieved using each of these materials will be described.

In Fig. 1, 1 indicates subgrade straightening work. After the site has been prepared, a predetermined gradient based on the survey is taken for the roadbed, and then the roadbed is leveled so as not to interfere with subsequent construction work. In this case, the thickness below the roadbed surface is approximately 1
The subgrade soil bearing capacity of the section m should be at least design CBR2.5,
If the value is less than that, measures such as installing a barrier layer will be taken in accordance with the "Japan Road Association Asphalt Pavement Guidelines."

Approximately 10 cm of crushed stone (e.g. C-40) is spread on the roadbed after leveling (for cold regions, this will be taken into account depending on the freezing depth), and it is thoroughly compacted using a roller etc. The land is modified to have the required slope. This is the process of crushed stone roadbed work 2.

On the other hand, granulated slag as aggregate, additives mainly consisting of inorganic salts, cement, binder, etc. are carried in (3), and the required amounts of these are mixed (4) in a soil mixer. In this case, a soil mixer is effective because it does not cause uneven mixing. It is also possible to incorporate colorants during mixing. The composition of the mixture is 1 m ³ of granulated slag, 1 Kg/m ³ of additive, and 0.2 of binder.
/m ² (construction after pressurization), but the amount of Portland cement added to this mixture was 4%, 6%.
% and 8%. Portland cement is preferred because it increases the unconfined compressive strength (qu) of the pavement.
However, on the other hand, it somewhat lowers the hydraulic conductivity. In order to ensure the hydraulic conductivity of this method in the range of 10 ^-2 to ^{10 -3} cm/sec, up to 16% cement is allowed.

Next, in step 5, the discharged mixture is laid on the crushed stone roadbed produced in step 2 described above, and further pressurized. This is the step numbered 6. Approximately 100 mm of crushed stone roadbed is formed on the roadbed, which is usually local soil, and a mixture is laid on top of it to form a surface layer of approximately 100 mm.

In this step, it is preferable to install the upper formwork on the crushed stone roadbed and lay the mixture. Pay special attention to levelness when finishing. In addition, consideration must be given to suspending construction during rain or snow, or if these are expected. The pressure is preferably rolled using a small roller plate or the like. Care should be taken as excessive compaction may lead to fragmentation of aggregate particles in the surface area.

After pressurization, there is a curing process indicated by reference numeral 7. It is usually preferable to cure for about 1/2 month, either by leaving it naturally or by covering it with a cover.

At the end of curing, that is, when qu reaches the design value, a surface treatment process using a binder, indicated by reference numeral 8, begins. The binder is sprinkled on the surface and impregnated to prevent the paved surface from peeling off. An emulsion type bond is suitable for the binder.

Paving is completed through the above steps. Paving made with this method has excellent permeability, so it does not form puddles due to rainfall, making it extremely convenient for roads, especially promenades, light vehicle paths for bicycles, sports facilities such as tennis courts, and park plazas. . Furthermore, it is extremely suitable for steel towers that are scattered in urban areas or relatively remote areas and surrounded by houses, fields, forests, etc., and completely prevents weeds from growing, and requires special drainage equipment. It has many advantages, such as being economical because it does not require mixing and stirring on site.

b. Because it is permeable, rainwater is returned to the soil, which has a positive impact on the growth of vegetation around the pavement.

(c) Since granulated slag has a relatively angular shape, the texture of the pavement surface is relatively rough, making it less slippery even during rainy weather. In the case of light vehicles, surface peeling is eliminated.

e By mixing colorants, it is possible to emphasize the color tone and texture of the material, which are close to those of natural soil.

f. During construction, on-site mixing work is possible, and large construction machinery is not required.
It has a narrow width and can be constructed even in curved areas and areas with steep vertical slopes.

g. Partial repairs are possible at any time.

〔Effect of the invention〕

Since the present invention is based on the above configuration,
Permeable pavement can be constructed easily and quickly, and the additives used, such as granulated slag and inorganic salts, are relatively inexpensive, making it extremely economically advantageous. Since the properties are relatively uniform, it has many advantages such as easy construction management and high safety, making it an extremely useful invention.

[Brief explanation of drawings]

Figure 1 is a flowchart of each step of this construction method. 1... Roadbed preparation work, 2... Crushed stone roadbed work, 3...
Bringing in aggregate, inorganic salt additives, cement, etc., 4...
Mixing with soil mixer, 5...Carrying out the mixture, 6...
...Laying/processing, 7...Curing, 8...Surface treatment with binder.

Claims (1)

[Claims] 1. Based on granulated slag, 20 to 30 parts by weight of sodium chloride, 20 to 30 parts by weight of magnesium chloride, 35 to 45 parts by weight of potassium chloride, 5 to 15 parts by weight of calcium chloride, and 4 to 8 parts by weight of citric acid. A pavement construction method characterized by forming a water-permeable pavement by laying a mixture prepared by adding an additive mainly composed of inorganic salts consisting of parts by weight on a leveled roadbed. 2. The paving method according to claim ¹ , wherein a mixture in which approximately 1 kg of the additive is added as an aqueous solution to 1 m 3 of granulated slag is laid. 3. The paving method according to claim 1, wherein the mixture contains Portland cement in an amount of 16% by weight or less based on the mixture. 4. The paving method according to claim 1, wherein a binder is sprinkled on the surface of the laid mixture.