JPH02266005A - Hydraulic simple paving method - Google Patents

Abstract

PURPOSE:To contrive to improve durability of pavement by blending steelmaking slags having specified grain size and specified mixture ratio in weight per cent with granulated blast furnace slags and uniformly laying the same over a subgrade, and by spraying bituminous material and, as occasion demands, granulated blast furnace slages over the surface st specified rate of quantity. CONSTITUTION:A material is made by blending granulated blast furnace slags and crushed steelmaking slags in 40mm or below grain size in 30-70 weight per cent mixture, and the said material is uniformly laid over a roller-compacted base course. After giving sufficient compaction thereon with a roller or the like, bituminous material such as asphalt emulsion or the like is sprayed thereon at a rate of 0.8-1.5l/m<2>. If occasion demands use at quickest possible time after execution of work, granular material such as granulated blast furnace slags or the like is sprayed further thereon at e rate of 5-10kg/m<2>. Thereby durability of the pavement can be improved by elaborate combination of slags in different properties and, at the same time, term of works can be shortened as the work does not require asphalt concrete, and deterioration of the work environment can be prevented as the work can be executed at the normal temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a simple hydraulic paving method, and more specifically, it relates to a simple hydraulic paving method for parking lots, etc., which has improved durability by utilizing the hydraulic properties of granulated blast furnace slag. This relates to a simple paving method.

(Conventional technology) Paving for parking lots, etc. is usually designed and constructed based on the Asphalt Paving Guidelines (edited and published by the Japan Road Association).
The structure consists of 3 asphalt concrete on top of the roadbed material.
It is paved to a thickness of ~5cm, but if economic efficiency is important when paving a simple parking lot, paving asphalt concrete can be omitted and a bituminous material such as asphalt emulsion is sprinkled on the surface of the roadbed material. Surface treatment methods are being used.

(Problems to be Solved by the Invention) The conventional surface treatment method as described above supports the load by interlocking the aggregates used in the roadbed material, and prevents the movement of the aggregates by the adhesiveness and viscosity of the bituminous material. However, the problem was that the surface protection ability of the bituminous material was lost over time, resulting in poor durability.

(Means for Solving the Problems) The present invention has been made to advantageously solve the problems of the prior art. The old material mixed with 30-70% is leveled on the roadbed or sub-base course, and after compaction, bituminous material such as asphalt emulsion is sprinkled on the surface at 0.8-1.5℃/m2. Hydraulic simple paving method characterized by (2) The hydraulic paving method according to item (1) above, characterized in that 5 to 10 kg/m2 of granular material such as granulated blast furnace slag is sprinkled on top of the bituminous material. The gist is a simple paving method.

The reasons for the limitations of the present invention will be described below.

In the present invention, the mixing ratio of steelmaking slag and granulated blast furnace slag is determined from laboratory test results, and defines a range in which the bearing capacity and compressive strength of the roadbed material are at desirable values. That is, Tables 1 and 2 show the chemical composition and particle size distribution of steelmaking slag and granulated blast furnace slag, and Table 3 shows the laboratory test results of the mixed material. When 30 to 70% (by weight) of steelmaking slag is mixed in, the modified CBR, which represents the interlocking strength of aggregate, is large.
In addition, since the axial compressive strength increased significantly, the mixing ratio of granulated blast furnace slag and steelmaking slag was determined to be 30 to 70% by weight of granulated blast furnace slag and steelmaking slag.

Table 1 Chemical component unit % Table 2 Particle size distribution (passing weight percentage) Table 3 Indoor test results of mixed materials 30 to 50 slowly cooled slag
It is effective to improve particle size by mixing % (weight/external ratio).

If the amount of bituminous material to be spread is less than 0.8 fl/m2, the adhesion force will be insufficient and the road surface will be damaged by movement of aggregate due to traffic load before the granulated blast furnace slag hardens, so the lower limit should be set to 0.8 fl/m2. ℃/m2, and conversely, the spray amount is 1.5u/m2.
If it exceeds m2, enforcement becomes difficult, so the upper limit is set at 15λ/
m2.

The reason why the grain size of the steelmaking slag is set to 40 mm or less is to effectively exhibit the interlocking effect of the aggregate, and from the viewpoint of the interlocking effect, the lower limit is preferably 5 mm or more. Granular materials such as granulated blast furnace slag that are sprinkled on bituminous materials are intended to be used as soon as possible after construction, and this purpose can be achieved with a spraying amount within the range of 5 to 10 kg/m2. . The granular material need not be limited to granulated blast furnace slag, and may be steelmaking slag or natural material as long as it is granular.

(Function) Granulated blast furnace slag has latent hydraulic properties that harden through a hydration reaction in the presence of alkali and water, steelmaking slag has basic properties, and bituminous slag has adhesive properties. Therefore, the present invention skillfully combines and utilizes the properties of these moon phases, and the period during which granulated blast furnace slag hardens at the initial stage of construction is controlled by the interlocking and history of steelmaking slag as an aggregate. The load is supported by the adhesive strength of the two materials, and then the load is resisted by the granulated blast furnace slag, which is hardened by the alkali in the steelmaking slag.

(Example) An example of paving an unpaved area that was used as a parking lot by changing the composition of the paving material will be shown.

After pulling the original ground to make it flat, we rolled it with a macadam roller. On top of that, the mixing ratio of granulated blast furnace slag and steelmaking slag was 60:40.50 and 50.
40: [Spread the paving material mixed in io with a grater, thoroughly roll it with a makatam roller, and reduce the finished thickness to 1.
．． Ocm. Immediately thereafter, asphalt emulsion was spread at 12°C/m2, and a very thin layer of granulated blast furnace slag was spread in order to use the area as a parking lot as soon as possible.

It was opened as a parking lot 24 hours after construction, and even after more than a month had passed, there was no damage to the surface at all, and the flat plate loading test results in Table 4 showed that there was a slight increase in the values for all three types of mixed materials.
It was confirmed that the hydraulic properties of granulated blast furnace slag were demonstrated.

Table 4 Results of flat plate loading test (effects of the invention) The present invention is constructed in exactly the same manner as conventional simple pavement, but due to the physical and chemical properties of each slag, it becomes a durable pavement. Because it does not use asphalt concrete, the construction period is short, and because the work is carried out at room temperature, it does not degrade the working environment.

4 others

Claims (1)

[Claims] 1. A material made by mixing granulated blast furnace slag with 30 to 70% by weight of steelmaking slag crushed to 40 mm or less is spread on a roadbed or lower roadbed, and after being compacted, it can be used as an asphalt emulsion or the like. Hydraulic simple paving method 2 characterized by spreading bituminous material at 0.8 to 1.5 l/m^2 on the surface.After spreading bituminous material, granular material such as granulated blast furnace slag is applied at 5 to 50 ml/m2. The simple hydraulic paving method according to claim 1, characterized in that 10 kg/m^2 is sprayed.