JP4680451B2 - Permeable concrete products and road paving - Google Patents

Description

【００２４】
３．成形及び養生
試験例１〜18の各粒体（混練物）を、気温５℃又は20℃の条件下で、100×60×15cmの型枠に投入し、空隙率が15％となるようにテーブルバイブレータで成形した（6000vpm×30秒）。成形後、養生シートでコンクリート表面を覆い、表２に示す条件（気温及び期間）で養生して、100×60×15cmの成形体を作製した。
【００２５】
４．評価
上記各粒体（混練物）を、型枠に投入し成形する際の作業性を、「○：良好」「×：悪い」で評価した。
また、上記成形体を切断して、10×10×40cmの供試体を３本作製し、「JIS A 1106（コンクリートの曲げ試験方法）」に準じて曲げ強度を測定した。
また、上記成形体を切断して、10×10×20cmの供試体を３本作製し、「インターロッキングブロック舗装設計施工要領 8-3 透水性試験」に準じて、透水係数を測定した。
それらの結果を表２に示す。
【００２６】
【表２】

【００２７】
表２から、本発明で規定する透水性コンクリート製品では、作業性や早期強度発現性に優れていることが分かる。特に、早強ポルトランドセメントを使用した場合では、材齢１日で4.0N/mm²以上の曲げ強度を発現した。
【００２８】
【発明の効果】
以上説明したように、本発明の透水性コンクリート製品では、早期強度発現性に優れるものであり、特に、早強ポルトランドセメントを使用した場合、早期強度発現性に優れる。また、低温環境下（気温２〜10℃程度）においても、混練物の作業性が良好であるので、製造が容易である。したがって、本発明の透水性コンクリート製品では、コンクリート製品の製造の効率を向上させることができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a permeable concrete product used for sidewalks, road pavements, and the like, and is particularly excellent in early strength development and is easy to manufacture even when manufactured in a low temperature environment (temperature 2-10 ° C.). It relates to a certain permeable concrete product.
[0002]
[Prior art]
Permeable concrete has good characteristics such as good drainage of rainwater, sound absorption and planting of vegetation, so it can be used for various applications such as road pavement, road side walls, river revetment, etc. It has been. However, since water-permeable concrete has voids inside, it has a lower bending strength than normal concrete and is difficult to apply to a high-traffic roadway.
[0003]
In recent years, as a result of research to overcome this problem of strength, permeable concrete that combines excellent water permeability and high bending strength has been developed, and its use as a paving material for high-traffic roadways has also been studied. ing. For example, in JP-A-7-206537, a water-permeable concrete having a large bending strength and a good water permeability can be obtained by specifying the blending amount, constituent components, etc. of the paste or mortar used together with the coarse aggregate. It is disclosed.
[0004]
[Problems to be solved by the invention]
Since the water-permeable concrete described in the above publication has high strength (such as bending strength), it can be applied to a roadway with a large amount of traffic. However, in order to develop a predetermined strength, it is necessary to cure at room temperature (about 20 ° C.) for 7 days or more, which is troublesome.
Moreover, when the water-permeable concrete described in the above publication is produced in a low-temperature environment (at a temperature of about 2 to 10 ° C.), there is a problem that workability of the kneaded material is reduced and work such as molding is troublesome. .
Therefore, improvement of the early strength development and improvement of workability of the kneaded material in a low temperature environment (temperature 2-10 ° C.) have been desired.
[0005]
[Means for Solving the Problems]
As a result of earnest research to solve the above problems, the present inventors,
The inventors have found that the above problems can be solved by specifying the components of the concrete and also specifying the blending ratio thereof, and the present invention has been completed.
[0006]
That is, the present invention is a water permeable product formed by putting a kneaded product of a composition comprising a coarse aggregate and a paste or mortar having a volume ratio of 30 to 80% with respect to the coarse aggregate into a mold, and curing the composition. In which the above paste or mortar is ordinary Portland cement or early strength Portland cement 100 parts by weight, ultrafine powder 0.5 to 4.5 parts by weight, fine aggregate 0 to 150 parts by weight, water reducing agent 0.1 to 3.0 parts by weight, A water-permeable concrete product comprising only 15 to 30 parts by mass of water, wherein the water reducing agent is a naphthalenesulfonic acid-based or polycarboxylic acid-based water reducing agent (Claim 1).
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
The material which comprises the water-permeable concrete product of this invention, and its compounding ratio are as follows.
(1) Coarse aggregate The coarse aggregate includes gravel having a particle size of 2.5 to 40 mm, crushed stone, or a mixture thereof, and a lightweight aggregate.
[0008]
(2) Cement The cement used in the present invention is ordinary Portland cement or early-strength Portland cement. By using the specific cement, it is possible to develop a bending strength of 4.0 N / mm ² or more at an early stage (within 5 days of material age). The bending strength of 4.0 N / mm ² or more can be expressed in a day), and the workability of the kneaded material is good even in a low temperature environment (temperature 2-10 ° C.).
[0009]
(3) Ultrafine powder As the ultrafine powder used in the present invention, an average particle diameter of 5.0 μm or less, preferably an average particle diameter of 3.0 μm or less, more preferably an average particle diameter of 1.0 μm or less, Examples include ash, fine limestone powder, fine silica powder, and silica fume. As the ultrafine powder, blast furnace slag fine powder and / or silica fume are preferable from the viewpoint of early strength development and workability of the kneaded material in a low temperature environment (at a temperature of about 2 to 10 ° C.).
[0010]
The addition amount of the ultrafine powder is 0.1 to 5.0 parts by mass, preferably 0.5 to 4.5 parts by mass, more preferably 1.0 to 4.0 parts by mass with respect to 100 parts by mass of normal Portland cement or early strong Portland cement (hereinafter abbreviated as cement). Part. When the addition amount of the ultrafine powder is less than 0.1 parts by mass with respect to 100 parts by mass of cement or exceeds 5.0 parts by mass, the early strength development is reduced, which is not preferable.
[0011]
(4) Fine aggregate Examples of the fine aggregate include 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, particles having a particle size of less than 5 mm, preferably 2.5 mm or less, more preferably 1.0 mm or less are used, and the particle size of the coarse aggregate is In the case of 2.5 to 5 mm, a particle having a particle size of less than 2.5 mm, preferably 1.5 mm or less, more preferably 0.5 mm or less is used. When the particle size of the fine aggregate is too close to the particle size of the coarse aggregate, it becomes difficult to coat the coarse aggregate with the mortar, which is not preferable.
[0012]
The addition amount of the fine aggregate is 0 to 150 parts by mass, preferably 20 to 140 parts by mass, and more preferably 30 to 130 parts by mass with respect to 100 parts by mass of cement. By adding a fine aggregate, shrinkage due to drying after curing can be suppressed. When the amount of fine aggregate added exceeds 150 parts by mass with respect to 100 parts by mass of cement, early strength development is reduced and workability of the kneaded material in a low-temperature environment (temperature of about 2 to 10 ° C.) is also reduced. Therefore, it is not preferable.
[0013]
(5) Water reducing agent The water reducing agent used in the present invention includes lignin-based, naphthalenesulfonic acid-based, melamine-based, and polycarboxylic acid-based water reducing agents (including AE water reducing agents, high-performance water reducing agents, and high-performance AE water reducing agents). ). In the present invention, it is preferable to use a naphthalene sulfonic acid-based or polycarboxylic acid-based water reducing agent in consideration of early strength development and workability of the kneaded material under a low temperature environment (temperature 2-10 ° C.). .
The water reducing agent can be used in a liquid or powder form.
[0014]
The addition amount of the water reducing agent is 0.1 to 3.0 parts by mass, preferably 0.3 to 2.0 parts by mass in terms of solid content, with respect to 100 parts by mass of cement. If the amount of the water reducing agent added is less than 0.1 parts by mass in terms of solid content, the workability of the kneaded product is lowered and the early strength development is also lowered, which is not preferable. On the other hand, even if an amount exceeding 3.0 parts by mass is added, the workability of the kneaded material is hardly improved and the cost is increased. Moreover, when there is too much addition amount of a water reducing agent, the runoff of a paste or mortar will also occur and a water permeability coefficient becomes small, and it is not preferable.
[0015]
(6) The amount of water is 15 to 30 parts by mass, preferably 16 to 28 parts by mass with respect to 100 parts by mass of cement.
If the amount of water is less than 15 parts by mass, the workability of the kneaded product is lowered, and the early strength development is also lowered. When the amount of water exceeds 30 parts by mass, the granules after granulation are bonded to each other, so that the particles do not become independent from each other, the paste or mortar also flows down, and the water permeability coefficient becomes small.
[0016]
(7) Volume ratio of paste or mortar to coarse aggregate The volume ratio of paste or mortar to coarse aggregate is 30 to 80% (outer percentage) with respect to 100% of coarse aggregate. If the volume ratio of the paste or mortar is less than 30%, the early strength development is low, which is not preferable. If the volume ratio of the paste or mortar exceeds 80%, the granules after granulation are bonded to each other, so that the granules do not become independent from each other, the paste or mortar also flows down, and the water permeability coefficient becomes small, which is not preferable. .
[0017]
The manufacturing method of the water-permeable concrete product of this invention is demonstrated.
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 biaxial mixer.
The kneading method is not particularly limited. For example, (1) a method in which materials are collectively put into a mixer and kneaded for 1 minute or more, and (2) after materials other than water are put in the mixer and kneaded empty. And a method of adding water and kneading for 1 minute or more.
In the present invention, the kneading is carried out until the coarse aggregates become independent granules (kneaded material) in a state where the coarse aggregate is coated with a paste or mortar made of a material other than the coarse aggregate.
[0018]
After kneading, the kneaded product is put into a predetermined mold and is preferably subjected to vibration molding with external vibration having a frequency of 3000 to 8000 vpm. If the frequency is less than 3000 vpm, sufficient compaction may not be performed, and the bending strength may be reduced. If the frequency exceeds 8000 vpm, the paste or mortar may flow down and the water permeability may be reduced.
The vibration molding can be performed using a table vibrator or a vibrator that can be attached to a formwork. The vibration time is approximately 4 to 30 seconds.
In addition, a pressure of 1 to 100 kPa may be applied during vibration molding. For pressurization, a hydraulic or pneumatic pressurizer or the like can be used.
In the present invention, the curing method is not particularly limited.
[0019]
The water-permeable concrete product of the present invention is formed into a block shape or the like, and can be suitably used for applications such as road pavements, sidewalks, parking lots, road side walls, river revetments. The thickness of the product may be determined according to the application, for example, 25 to 30 cm in the case of a high-traffic roadway.
[0020]
The permeable concrete product of the present invention is excellent in early strength development, and can exhibit a bending strength of 4.0 N / mm ² or more within 5 days of age. In particular, when early-strength Portland cement is used as the cement, a bending strength of 4.0 N / mm ² or more can be developed in one day of material age.
Moreover, the water-permeable concrete product of this invention is excellent in workability | operativity, such as shaping | molding, also in a low temperature environment (temperature 2-10 degreeC).
[0021]
[Test example]
Hereinafter, the present invention will be described with test examples.
1. Materials used The following materials were used.
(1) Cement A: Early strong Portland cement (manufactured by Taiheiyo Cement Co., Ltd.)
Cement B: Ordinary Portland cement (manufactured by Taiheiyo Cement Co., Ltd.)
(2) Silica fume; Elchem microsilica (manufactured by Elchem Japan, average particle size 0.15 μm)
(3) Blast furnace slag: Fine Serament 10A (Daiichi Cement Co., Ltd., average particle size 3.0 μm)
(4) Fine aggregates; Hosameyama sand (original size: 2.5mm or less)
(5) Coarse aggregate: Ome crushed stone No. 6 (particle size 5-13mm)
(6) Water reducing agent A: “Mighty 100” (Naphthalenesulfonic acid type, manufactured by Kao Corporation)
Water reducing agent B: “Core Flow NF-100” (polycarboxylic acid, manufactured by Taiheiyo Cement Co., Ltd.)
▲ 7 ▼ Water; Tap water [0022]
2. Blending and kneading of water-permeable concrete Using the above materials, according to the blending shown in Table 1, each material is put into a biaxial forced kneading mixer (0.1m ³ ) and kneaded for 4 minutes. Particles (kneaded material) independent from each other in a state of being coated with a paste or mortar made of a material other than the above were prepared.
[0023]
[Table 1]

[0024]
3. Each granule (kneaded material) of molding and curing test examples 1 to 18 is introduced into a mold of 100 × 60 × 15 cm at a temperature of 5 ° C. or 20 ° C. so that the porosity is 15%. Molded with a table vibrator (6000 vpm x 30 seconds). After molding, the concrete surface was covered with a curing sheet and cured under the conditions (temperature and period) shown in Table 2 to produce a molded body of 100 × 60 × 15 cm.
[0025]
4). Evaluation The workability when each of the above granules (kneaded material) was put into a mold and molded was evaluated as “◯: good” or “×: bad”.
The molded body was cut to prepare three 10 × 10 × 40 cm specimens, and the bending strength was measured according to “JIS A 1106 (concrete bending test method)”.
Further, the molded body was cut to prepare three 10 × 10 × 20 cm specimens, and the permeability coefficient was measured according to “Interlocking Block Pavement Design and Construction Procedure 8-3 Permeability Test”.
The results are shown in Table 2.
[0026]
[Table 2]

[0027]
From Table 2, it can be seen that the permeable concrete product defined in the present invention is excellent in workability and early strength development. In particular, when early-strength Portland cement was used, a bending strength of 4.0 N / mm ² or more was developed at a material age of 1 day.
[0028]
【The invention's effect】
As described above, the water-permeable concrete product of the present invention is excellent in early strength development. In particular, when early strength Portland cement is used, the early strength development is excellent. Moreover, since the workability of the kneaded material is good even in a low-temperature environment (temperature of about 2 to 10 ° C.), the production is easy. Therefore, in the water-permeable concrete product of this invention, the efficiency of manufacture of a concrete product can be improved.

Claims (4)

A kneaded product of a composition composed of a coarse aggregate and a paste or mortar with a volume ratio of 30 to 80% to the coarse aggregate is molded into a mold, molded, and cured, ,
The paste or mortar, ordinary Portland cement or high-early-strength portland cement 100 parts by weight, micronized 0.5 to 4.5 parts by mass, fine aggregate 0 to 150 parts by weight water-reducing agent 0.1 to 3.0 parts by weight of water 15 to 30 parts by weight It consists of only,
The water- permeable concrete product, wherein the water reducing agent is a naphthalenesulfonic acid-based or polycarboxylic acid-based water reducing agent .  The water-permeable concrete product according to claim 1, wherein the ultrafine powder is blast furnace slag fine powder and / or silica fume.  The water-permeable concrete product according to claim 1 or 2, wherein the molding is vibration molding by external vibration having a frequency of 3000 to 8000 vpm.  A road pavement comprising the water-permeable concrete product according to any one of claims 1 to 3.