JP2002302904A - Cast-in-place water permeable concrete pavement construction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cast-in-place water permeable concrete pavement construction method capable of opening traffic in an early stage even when construction is carried out in a low temperature environment (at a temperature of about 2-10 deg.C). SOLUTION: In this cast-in-place water permeable concrete pavement construction method, a kneaded composition consisting of coarse aggregate and paste/ mortar with a volume ratio of 30-80% of the coarse aggregate is compacted by a pressurization vibrator to be laid on a construction field. Subsequently, the surface of the water permeable concrete pavement is covered with a heat curing sheet to be cured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a construction method of in-situ permeable concrete pavement that enables early traffic opening even when constructed at about 2-10 ° C.

[0002]

2. Description of the Related Art Permeable concrete has characteristics such as good drainage of rainwater, sound absorption, and planting of vegetation. Therefore, permeable concrete is suitable for road pavement, road side walls, river bank protection, and the like. It is used for various applications. However, since the permeable concrete has voids inside, it has a lower bending strength than ordinary concrete, and it has been difficult to apply the permeable concrete to a road with a large traffic volume.

[0003] In recent years, as a result of research into overcoming the problem of strength, permeable concrete having both excellent water permeability and large bending strength has been developed and used as a pavement material for roads with heavy traffic. Have been. For example,
No. 9-273105 discloses that by specifying the amount of the paste or mortar used together with the coarse aggregate, the constituent components, etc., a cast-in-place permeable concrete pavement having a large bending strength and a good water permeability can be obtained. Is disclosed.

[0004]

However, in the in-place permeable concrete pavement described in the above-mentioned publication, when the construction is performed in a low-temperature environment (temperature of about 2 to 10 ° C.), a predetermined bending strength is developed. Need to be cured for more than 7 days. Therefore, when the in-place permeable concrete pavement is applied to a roadway or the like, traffic must be cut off during the curing period (7 days or more). for that reason,
Even when constructed in a low temperature environment (temperature about 2-10 ° C),
There has been a demand for a method of constructing a pavement-permeable permeable concrete pavement that enables early traffic opening.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, after laying a kneaded material having a specific (paste or mortar) / coarse aggregate volume ratio on a construction site, It has been found that the above problem can be solved by curing using a heat-curing sheet, and the present invention has been completed.

That is, according to the present invention, a kneaded product of a composition comprising coarse aggregate and a paste or mortar having a volume ratio of 30 to 80% with respect to the coarse aggregate is compacted by a pressure vibrator to a construction site. This is a method of constructing a pour-in-place permeable concrete pavement, characterized in that after laying, the surface of the permeable concrete pavement is covered with a heat curing sheet and cured (claim 1).

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. In the construction method of the cast-in-place permeable concrete pavement of the present invention, first, the coarse aggregate, the volume ratio to the coarse aggregate is
A kneaded mixture of a composition comprising 30 to 80% paste or mortar is compacted with a pressure vibrator and spread on a construction site. If the volume ratio of paste or mortar to coarse aggregate is less than 30%, strength development is low and it is difficult to develop bending strength of 4.5 N / mm ² or more, making it difficult to apply to roads with heavy traffic. Is not preferred. If the volume ratio of the paste or mortar exceeds 80%, the water permeability of the water permeable concrete pavement is undesirably small.

In the present invention, examples of the coarse aggregate include gravel, crushed stone, a mixture thereof, and lightweight aggregate having a particle size of 2.5 to 20 mm. The paste or mortar is composed of 100 parts by weight of cement or a powder mixture containing cement, 0 to 150 parts by weight of fine aggregate, 0.1 to 2.0 parts by weight of a water reducing agent, and 15 parts of water.
Preferably, it contains about 30 parts by weight.

The materials constituting the paste or mortar and the mixing ratio thereof will be described. (1) Cement or powder mixture containing cement Portland cement such as Portland cement such as ordinary, early strength, moderate heat and low heat Portland cement, white cement, alumina cement, and municipal waste incineration ash
Cement (eco-cement) using waste such as sewage sludge incineration ash as a raw material is exemplified. The powder mixture containing cement has a specific surface area of 3000 cm for the cement.
² / g or more of inorganic powder such as blast furnace slag powder, fly ash, limestone powder, silica stone powder, silica fume and the like. As the inorganic powder, blast furnace slag powder, fly ash and / or silica fume are preferred. The proportion of the cement in the powder mixture containing the cement is preferably 50% by weight or more.
It is more preferable that the content be not less than% by weight.

(2) Fine aggregate The fine aggregate includes river sand, sea sand, mountain sand, crushed sand, or a mixture thereof. As the fine aggregate, when the particle size of the coarse aggregate is 5 mm or more, a particle having a particle size of less than 5 mm, preferably 2.5 mm or less, more preferably 1.0 mm or less is used. In the case of 2.5 to 5 mm, particles having a particle size of less than 2.5 mm, preferably 1.5 mm or less, more preferably 0.5 mm or less are used. If the particle size of the fine aggregate is too close to the particle size of the coarse aggregate, it is difficult to coat the mortar on the coarse aggregate, and the water permeability coefficient of the permeable concrete pavement is not preferable. The amount of fine aggregate added is cement or powder mixture containing cement 10
The amount is preferably 0 to 150 parts by weight, more preferably 20 to 140 parts by weight, still more preferably 30 to 130 parts by weight with respect to 0 parts by weight. By adding fine aggregate, shrinkage due to drying after curing can be suppressed. 15 fine aggregate added
If the amount exceeds 0 parts by weight, it is difficult to develop a bending strength of 4.5 N / mm ² or more at an early stage, and it is difficult to quickly open the traffic, which is not preferable.

(3) Water The amount of water depends on the amount of cement or powder mixture containing cement.
The amount is preferably 15 to 30 parts by weight, more preferably 16 to 28 parts by weight with respect to parts by weight. If the amount of water is less than 15 parts by weight, the workability will be reduced and the bending strength of 4.5 N / mm ² or more will be exhibited at an early stage when constructed in a low temperature environment (temperature of about 2 to 10 ° C). It is not preferable because it is difficult to open the traffic early. If the amount of water exceeds 30 parts by weight, the water permeability of the permeable concrete pavement becomes small, which is not preferable.

(4) Water reducing agent As the water reducing agent, a lignin-based, naphthalenesulfonic acid-based, melamine-based, polycarboxylic acid-based water reducing agent, an AE water reducing agent, a high performance water reducing agent or a high performance AE water reducing agent is used. Can be. Among these, it is preferable to use a high performance water reducing agent or a high performance AE water reducing agent having a large water reducing effect. The compounding amount of the water reducing agent is preferably 0.1 to 2.0 parts by weight in terms of solid content based on 100 parts by weight of cement. If the amount of water reducing agent (in terms of solid content) is less than 0.1 part by weight with respect to 100 parts by weight of cement, if the construction is performed in a low temperature environment (temperature about 2 to 10 ° C),
Workability deteriorates, and it is difficult to develop a bending strength of 4.5 N / mm ² or more. On the other hand, even if the amount exceeds 2.0 parts by weight (in terms of solid content), the workability is hardly improved and the cost increases. On the other hand, when the amount of the water reducing agent is too large, the water permeability of the permeable concrete pavement is undesirably small. The water reducing agent can be used in either liquid or powder form.

In the present invention, a thermoplastic resin such as an ethylene / vinyl acetate copolymer or an acrylic copolymer may be added to the paste or mortar as long as the purpose is not impaired. Further, a pigment such as red iron oxide may be added as long as the purpose is not impaired.

In the present invention, the method of kneading the composition comprising the coarse aggregate and the paste or mortar is not particularly limited. For example, the above-mentioned materials are put into a mixer at once and kneaded for 1 minute or more. And a method in which materials other than water are charged into the mixer and kneaded, and then water is charged and kneaded for 1 minute or more. The mixer used for kneading is not particularly limited, and may be kneaded with a conventional mixer such as a pan-type mixer or a twin-screw mixer. The transport of the kneaded material from the concrete factory to the construction site may be performed using either a dump truck or an agitator truck.

When the above-mentioned kneaded material is applied, the kneaded material is compacted by a pressure vibrator and spread on a construction site. As the pressure vibrator, a tamping rammer, a plate compactor, a vibro compactor, a finisher, and the like conventionally used for concrete pavement can be used. The compaction by the pressure vibrator is preferably performed such that the porosity of the permeable concrete pavement is 10 to 20% from the viewpoint of the permeability coefficient and strength of the permeable concrete pavement.
The thickness of the permeable concrete pavement is usually about 25 to 30 cm in the case of a road with a large traffic volume.

In the method for constructing a pour-in-place permeable concrete pavement of the present invention, after the above-mentioned kneaded material is laid on a construction site, the permeable concrete pavement surface is covered with a heat-curing sheet and cured. In curing by heating curing sheet,
Curing is preferably performed so that the temperature of the permeable concrete pavement is 15 to 35 ° C, and more preferably 20 to 35 ° C. If the temperature of permeable concrete pavement is 15 ℃ or more, under low temperature environment (air temperature about 2-10 ℃)
4.5N / mm ² early (within 5 days of age)
The above bending strength can be developed, and early traffic opening is possible. In particular, if the temperature of the permeable concrete pavement is 20 ° C. or more, a bending strength of 4.5 N / mm ² or more can be developed within 3 days, and earlier traffic opening is possible. If the temperature of the permeable concrete pavement is lower than 15 ° C., it is difficult to develop a bending strength of 4.5 N / mm ² or more at an early stage, and it is difficult to open the traffic at an early stage. When the temperature of the permeable concrete pavement exceeds 35 ° C, the temperature change of the permeable concrete pavement increases after the curing by the heat-curing sheet, and the volume changes (shrinks).
Is also undesirably large.

The heat-curing sheet used in the present invention is not particularly limited as long as the temperature of the permeable concrete pavement can be adjusted to 15 to 35 ° C.
It is preferable to use a heat-curing sheet having a function of automatically adjusting the electric power according to a change in the surrounding temperature and maintaining the temperature of the permeable concrete pavement at 15 to 35 ° C. As a heat curing sheet having such a function, for example,
A seat heater manufactured by Sekisui Plastics Co., Ltd. may be used.

In the present invention, the curing period with the heat-curing sheet is preferably 5 days or less, more preferably 3 days, from the early traffic opening of the permeable concrete pavement.
Within days.

[0019]

Test Examples Hereinafter, the present invention will be described with reference to examples. 1. Materials used The following materials were used. Cement A: Early strength Portland cement (manufactured by Taiheiyo Cement Corporation) Cement B: Ordinary Portland cement (manufactured by Taiheiyo Cement Corporation) Blast furnace slag: Fine cement 10A (manufactured by Daiichi Cement Corporation) Fine aggregate: City Original Hosoume sand (2.5 mm or less in particle size) Coarse aggregate; crushed stone from Ome No. 6 (5 to 13 mm in particle size) Water: Tap water High-performance water reducing agent: Mighty 100 (manufactured by Kao Corporation)

2. Mixing and kneading of permeable concrete Using the above-mentioned materials, each material is put into a 2-axis forced kneading mixer (0.1 m ³ ) at a time according to the mixing shown in Table 1, and kneaded for 4 minutes to obtain coarse aggregate. Independent granules (kneaded material) coated with a paste or mortar made of other materials were prepared.

[0021]

[Table 1]

3. Forming and curing Each of the above granules (kneaded material) is heated at a temperature of 5 ° C to 100 × 6
It was put into a 0 × 25 cm formwork and laid with a plate compactor (MVC-110H; manufactured by Mikasa Corporation) so that the porosity was 18%. After laying, the surface of the permeable concrete pavement is covered with a sheet heater manufactured by Sekisui Plastics Co., Ltd., and cured for the period shown in Table 2 so that the temperature of the permeable concrete pavement becomes the temperature shown in Table 2, and 100 × A 60 × 25 cm permeable concrete paving slab was prepared. The temperature of the permeable concrete pavement during curing is the temperature at the center of the permeable concrete pavement plate.

4. Evaluation The above pavement slab was cut, and three specimens measuring 10 × 10 × 40 cm were prepared. “JIS A 1106 (Bending test method for concrete)”
The bending strength was measured according to the above. In addition, the above-mentioned pavement slab was cut, three specimens of 10 × 10 × 20 cm were prepared, and the water permeability coefficient was measured according to “Interlocking Block Pavement Design and Execution Procedure 8-3 Permeability Test”. Table 2 shows the results.

[0024]

[Table 2]

From Examples 1 to 6 in Table 2, it can be seen that the method of constructing a cast-in-place permeable concrete pavement according to the present invention can quickly produce 4.5 N / m even in a low-temperature environment (temperature of 5 ° C.).
It exhibited a bending strength of m ² or more. On the other hand, in Comparative Examples 1 and 2, which did not use the heat-curing sheet, the early strength development was poor. Further, in Comparative Example 3 in which the mortar / coarse aggregate volume ratio was smaller than the stipulation of the present invention, the strength expression was poor. Also,
In Comparative Example 4 in which the mortar / coarse aggregate volume ratio was larger than that specified in the present invention, the hydraulic conductivity was extremely small.

[0026]

As described above, according to the construction method of cast-in-place permeable concrete pavement of the present invention, even in the case of construction in a low-temperature environment (temperature of about 2 to 10 ° C.), early traffic opening is possible. .

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Akira Kobatake 2-4-2 Daisaku, Sakura City, Chiba Pref. Central Research Institute, Pacific Cement Co., Ltd. F-term (reference) 2D051 AA02 AC05 AF01 AF02 AF03 AF05 AH03 EB04

Claims (3)

[Claims] 1. The method of claim 1, wherein the volume ratio of the coarse aggregate to the coarse aggregate is 30
After kneading the kneaded material of the composition consisting of ~ 80% paste or mortar and laying it on the construction site with a pressure vibrator,
A method for constructing an in-place permeable concrete pavement, wherein the surface of the permeable concrete pavement is covered with a heat-curing sheet and cured. 2. The paste or mortar is composed of 100 parts by weight of cement or a powder mixture containing cement, fine aggregate of 0 to 15 parts.
The method of claim 1, wherein the pavement contains 0 parts by weight, 0.1 to 2.0 parts by weight of a water reducing agent, and 15 to 30 parts by weight of water. 3. A cement or a powder mixture containing cement comprising 50 to 100% by weight of Portland cement and 50 to 0% by weight of one or more powders selected from blast furnace slag powder, fly ash and silica fume. Item 4. The construction method of the cast-in-place permeable concrete pavement according to Item 2.