JPH0343502A - Pavement method by use of water permeable cement-concrete mixed with steel fiber - Google Patents

Abstract

PURPOSE:To build a road-way which is durable against heavy duty traffics by paving a road surface or a road bed with water-permeable cement-concrete in which water cement, aggregates and the like are mixed by predetermined rates and which is mixed therein with a predetermined quantity of steel fibers. CONSTITUTION:0.1 to 2.0%, by volume, of steel fibers which have been subjected to rust-preservation are mixed in water-permeable cement concrete in which 20 to 40% of water cement and 0 to 40% of aggregates are mixed with a vacant rate of 10 to 20%. Further, thus obtained material is kneaded in a ready-mixed concrete plant or the like, and is then laid uniformly over a road bed or the like. Then, it is rolled and is cured. The thickness of the laid concrete is determined in accordance with a volume of traffics. With this arrangement, it is possible to obtain a pavement having a water-permeability, a high bending strength and a high slip resistance and being suitable for a heavy duty road-way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of paving with water-permeable cement concrete mixed with steel fibers.

[Prior Art] In recent years, rapid urbanization has increased the area where rainwater cannot penetrate, resulting in so-called urban flooding, in which a large amount of rainwater flows out in a short period of time after rainfall, and this has become a social problem. As a countermeasure for these, it is effective to allow rainwater to permeate into the ground as much as possible, which can prevent river flooding, improve the underground ecology of vegetation, and restore the natural system.

For this purpose, asphalt-based and cement-based water permeable pavements have been provided (for example, Japanese Patent Application Laid-open No. 150806/1983).

[Problem to be solved by the invention] However, conventional water permeable pavements are intended for sidewalks and heavy traffic, and have not been put into practical use for heavy traffic roads due to various mechanical properties and durability conditions. .

The object of the present invention is to provide a method of paving with water-permeable cement concrete mixed with steel fibers that can withstand heavy traffic on roadways.

[Means for Solving the Problems] According to the present invention, permeable cement concrete is mixed with a water-cement ratio of 25 to 40%, a fine aggregate ratio of 0 to 40%, and a porosity of 10 to 20%. , the volume of steel fiber with anti-corrosion treatment is 0. 1-2. 0% mixture is used to pave the roadbed or roadbed.

The above-mentioned rust-preventing steel fibers include stainless steel or galvanized steel with a length of 10 to 50 m and a cross-sectional area of 0.
1-1. 0! It is preferable to use generally commercially known fibers of nIA.

[Function] In the paving method using water-permeable cement concrete using steel fibers configured as described above, the mechanical properties such as bending strength and bending toughness are improved due to the inclusion of steel fibers compared to water-permeable cement concrete that does not use this material. This prevents the occurrence of cracks caused by deformation due to vehicle loads and expansion/contraction due to temperature changes.

In addition, since the steel fibers have been subjected to a rust-proofing treatment, rusting due to water permeation is prevented, and changes in the physical properties of the steel fibers due to rust are prevented.

[Example] The present invention will be described in detail below with reference to the drawings.

The water-permeable cement concrete according to the present invention is mixed as shown in FIG. Note that the steel fiber has a length of 10 to 50 mm and a cross-sectional area of 0. 1-1, 0InIA
Commercially available stainless steel fibers with the above formulation, e.g. For example, an acrylic resin emulsion is used in the shin patch.

The above water-cement ratio is a weight ratio, and if this ratio is less than 25%, the amount of water required for the hydration reaction will be insufficient and the required strength will not be obtained, and if it is more than 40%, the mixing of cement and water will be difficult. It becomes too fluid and does not adhere to the aggregate, so as mentioned above, it is set at 32°8%, for example.

In addition, the fine aggregate ratio is the volume ratio of fine aggregate (1) fine aggregate (2) and fine aggregate (1) fine aggregate (2) coarse aggregate,
If this ratio is 40% or more, fine aggregate (sand) fills the water passages and water permeability cannot be obtained.
It was adopted by 5.4%.

In addition, porosity is the ratio of space occupied in water-permeable concrete. If this ratio is less than 10%, the specified water permeability cannot be obtained, and if it is more than 20%, the strength will be insufficient. For example, 14% of respondents said that

In addition, the mixing rate of steel fibers can be determined by bending toughness (a prismatic material is supported at two points, the load-deflection curve is examined, and the span of the two-point support is 1, and the area of the load-deflection curve until the deflection becomes (A'/150) is called bending toughness). %, 0.5% and 2
% of each water permeable cement concrete B1 mixed with
In C and D, the contamination rate is 0. If it is less than 1%, it is not very effective, and if it is more than 2%, the bending strength and bending toughness are lower than that of 0.5%, so it is not very effective. It is being

The porosity is 14% and the steel fiber content is 0. For 5% permeable cement concrete C, mechanics such as bending strength, bending toughness and permeability coefficient,
Physical properties are improved as follows.

FIG. 3 shows the bending strength test results of plain permeable cement concrete A and permeable cement concrete C mixed with 0.5% steel fiber when the porosity was changed. As can be seen from this result, at a porosity of 14%,
The bending strength of concrete A is 49 kgf/cn
Concrete C increases to 51.7 kgf/cf with respect to f. By changing the above-mentioned porosity, a required bending strength of 40 to 60 kgf/at can be obtained.

In Figure 2, the bending toughness of concrete C is
The improvement is about three times that of concrete A.

FIG. 4 shows the test results of the hydraulic conductivity when the porosity was changed. As can be seen from this result, the porosity is 1
The permeability coefficient of the water permeable concrete C containing 0.5% of 4% steel fibers is about 4 X i O-2 am/sec, which is a value higher than the preferred permeability coefficient I X L O-2 cm/s eC.

When paving, the thickness of the permeable cement concrete mixed with steel fibers is determined according to the traffic volume as shown in Figure 5.

In addition, as shown in Fig. 6, the entire thickness of the plate thickness T is made of water permeable cement concrete C mixed with steel fibers, or as shown in Fig. 7, the upper layer of the plate thickness T is made of water permeable cement concrete mixed with steel fibers. C, and the lower layer is plain permeable cement concrete A, or as shown in Figure 8, the plate thickness is T.
The upper layer is plain permeable cement concrete A,
The lower layer can be made of water-permeable cement concrete C mixed with steel fibers. Among these, the pavement shown in Figures 6 and 7 has steel fibers on the surface, so it has high slip resistance and is ideal for automobile roads, and the pavement shown in Figure 8 has steel fibers on the surface. It is ideal for roads with a mixture of pedestrians and cars.

During construction, permeable cement concrete C mixed with steel fibers mixed with ready-mixed concrete, etc. is transported to the site by dump truck, and spread with paper on the roadbed or subgrade E.
After compaction with rollers, curing is performed.

[Effects of the Invention] Since the present invention is configured as described above, it produces effects as described below.

It has high bending strength, bending toughness, and high slip resistance, making it the most suitable method for paving roads with heavy traffic.

In addition, since it has an appropriate porosity, it is effective in returning rainwater to the ground, improving vegetation, and preventing river flooding, and can also eliminate the need for road drainage facilities.

[Brief explanation of drawings]

Fig. 1 is a drawing explaining a formulation example for carrying out the present invention, Fig. 2
The figure is a bending toughness characteristic diagram, Figure 3 is a porosity-bending strength characteristic diagram, Figure 4 is a porosity-permeability coefficient characteristic diagram, Figure 5 is a diagram explaining the relationship between traffic volume classification and plate thickness, and Figure 6 is a diagram explaining the relationship between traffic volume classification and plate thickness. Figures 8 to 8 are vertical sectional views of different pavement types. A...Plain permeable cement concrete C...
Permeable cement concrete mixed with 0.5% steel fiber E・・Roadbed or roadbed

Claims (1)

[Claims] Permeable cement concrete with a water-cement ratio of 25 to 40%, a fine aggregate ratio of 0 to 40%, and a porosity of 10 to 20% is mixed with 0.1 volume of rust-preventing steel fibers.
A method of paving using water-permeable cement concrete mixed with steel fibers, characterized in that the concrete containing ~2.0% of steel fibers is paved on a roadbed or roadbed.