JP2001072456A - Paste or mortar for joining water-permeable concrete, and method for joining water-permeable concrete - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paste or mortar which is disposed between an existing concrete cured article and water-permeable concrete to improve the adhesion strength, when the water-permeable concrete is newly built on the existing concrete cured article. SOLUTION: This paste or mortar for joining water-permeable concrete comprises 100 pts.wt. of a cement or a powder mixture containing the cement, 0 to 300 pts.wt. of a small aggregate, 0.2 to 2.0 pts.wt. (converted into solid content) of a water-reducing agent, 0.01 to 0.2 pt.wt. of a retarder, 0.5 to 5 pts.wt. of contraction-reducing agent, and water in such an amount that the total amount of the water and the contraction-reducing agent is 20 to 40 pts.wt. The powder mixture containing the cement preferably comprises >=50 wt.% of the cement and <=50 wt.% of one or more kinds of inorganic powder selected from blast furnace slag powder, fly ash and silica fume.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint between a hardened body such as an existing concrete pavement and a permeable concrete which is newly transferred to the hardened body. The present invention relates to a paste or mortar, and a method of joining permeable concrete using the paste or mortar.

[0002]

2. Description of the Related Art Permeable concrete has been put to practical use as a pavement for a sidewalk or a parking lot because drainage of rainwater or the like is improved. In recent years, permeable concrete having excellent water permeability and large bending strength has been developed, and its practical use on roads with heavy traffic has been promoted. Further, as a use other than the above-mentioned pavement, practical use as seawall concrete is also being studied.

Conventionally, permeable concrete cast in place is:
After the gravel was laid at the casting site, it was cast on the gravel. However, in order to further expand the applications of permeable concrete in the future, the establishment of technology for passing permeable concrete over existing hardened bodies (for example, hardened concrete such as concrete pavement and concrete structures, asphalt pavement, etc.) is necessary. In particular, it is very important to find a means for adhering the existing hardened body and the permeable concrete with a sufficient adhesion strength.

Conventionally, when new ordinary concrete is to be transferred over an existing hardened body (for example, a concrete structure), the construction has been performed in the following procedure. That is, first, the latency layer or the thin paste layer on the surface of the existing cured body is removed to form an uneven rough surface.
Then, a joint mortar is thinly applied on the rough surface of the cured product in a layered manner. Finally, new ordinary concrete is cast on the upper surface of the joint mortar. Here, as the mortar for jointing, mortar containing water, cement, fine aggregate and retarder is usually used. Also, in order to prevent temperature cracking at the time of splicing, Japanese Patent Application Laid-Open No. 63-7896 is disclosed.
No. 6 proposes a mortar containing components of water, cement, fine aggregate, super retarder and non-breathing agent.

[0005]

Heretofore, it has not been practiced to transfer permeable concrete to an existing hardened body. Therefore, if a paste or mortar of any composition is used for joining permeable concrete,
Until now, there was no knowledge whether sufficient adhesion strength could be obtained. Therefore, the present invention, when casting the permeable concrete on the existing hardened body, interposed between the existing hardened body and the permeable concrete, to improve the adhesive strength of the permeable concrete joint paste or It is an object of the present invention to provide a mortar and a method of joining permeable concrete using the paste or the mortar.

[0006]

Means for Solving the Problems The paste or mortar for transferring permeable concrete according to the present invention is a paste or mortar which is used by being interposed between an existing hardened body and permeable concrete to be transferred to the hardened body. Mortar,
100 parts by weight of cement or a powder mixture containing cement,
0 to 300 parts by weight of fine aggregate, 0.2 to 2.0 parts by weight of water reducing agent (in terms of solid content), 0.01 to 0.2 parts by weight of retarder, 0.5 to shrinkage reducing agent
5 parts by weight, and water mixed so that the total amount of the shrinkage reducing agent is 20 to 40 parts by weight (claim 1). By interposing the paste or mortar having the specific components and the mixing ratio between the existing hardened body and the permeable concrete in this manner, a large bonding strength can be given to the joint (joining surface). . The above-mentioned powder mixture containing cement comprises 50% by weight or more of cement and 50% by weight or less of blast furnace slag powder, fly ash,
It is preferable that it is composed of at least one inorganic powder selected from silica fume (claim 2).

[0007] The method of joining permeable concrete according to the present invention comprises a first step of casting the paste or mortar for joining permeable concrete on the upper surface of an existing hardened body.
Before the paste or mortar for permeable concrete is cured, a second step of casting permeable concrete on the upper surface of the paste or mortar for permeable concrete ( Claim 3). As described above, by using the specific joining paste or mortar and performing the joining operation before the paste or the mortar is hardened, a large adhesive strength can be given to the joining portion.

[0008] The jointing method may further include, between the first step and the second step, a step of spraying an anti-drying agent on the upper surface of the paste or mortar for joining the permeable concrete. Preferred (claim 4). By spraying the anti-drying agent in this way, it is possible to prevent the paste or mortar from drying, whereby
Even if the amount of the paste or mortar used is small, it is possible to obtain high adhesive strength.

Examples of the above-mentioned anti-drying agent include, for example, a general formula: RO (AO) _n H (wherein R is an alkyl group having 1 to 6 carbon atoms, and A is one or two of carbon atoms having 2 to 3 carbon atoms). A kind of alkylene group, n is an integer of 1 to 10), and an alkylene oxide adduct of a lower alcohol represented by the following formula: or a polyhydric alcohol such as polyethylene glycol.

[0010] In the joining method, prior to the first step, a latence layer or a thin paste layer on the upper surface of the existing cured body is removed using a wire brush or the like, and a rough surface having irregularities is removed. The method may further include a pre-treatment step of forming (claim 6). By including such a pretreatment step, it is possible to further increase the adhesive strength at the joint.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. (1) Cement or powder mixture containing cement Examples of the cement used in the present invention include Portland cement such as ordinary Portland cement, early-strength Portland cement, moderate heat Portland cement, low heat Portland cement, white cement, and alumina cement. Can be The powder mixture containing cement refers to a mixture obtained by adding an inorganic powder such as blast furnace slag powder, fly ash, limestone powder, silica stone powder, and silica fume to the above cement. Among inorganic powders, blast furnace slag powder, fly ash, and silica fume are preferred. The proportion of cement in the powder mixture containing cement is preferably 50% by weight or more in order to ensure strength development.

(2) Fine aggregate The fine aggregate used in the present invention includes river sand, sea sand, mountain sand, crushed sand, and a mixture thereof. The added amount of the fine aggregate is 0 to 300 parts by weight, preferably 30 to 100 parts by weight, based on 100 parts by weight of cement or a powder mixture containing cement. By adding the fine aggregate, it is possible to suppress the mortar from drying and shrinking after curing. If the amount of the fine aggregate exceeds 300 parts by weight, the workability of the mortar deteriorates, and the adhesive strength between the existing hardened body and the permeable concrete decreases.

(3) Water reducing agent Examples of the water reducing agent used in the present invention include alkyl allyl sulfonic acid type, naphthalene sulfonic acid type, melamine sulfonic acid type and polycarboxylic acid type water reducing agents. Among them, a high-performance water reducing agent or a high-performance AE water reducing agent has a large water reducing effect and is preferred. The water reducing agent may be used alone or in combination of two or more. In addition, either liquid or powder can be used.

The amount of the water reducing agent to be added is 0.2 to 2.0 parts by weight (in terms of solid content), preferably 0.3 to 1.5 parts by weight, based on 100 parts by weight of cement or a powder mixture containing cement. If the addition amount is less than 0.2 parts by weight, the workability of the paste or mortar becomes poor, which is not preferable. If the amount exceeds 2.0 parts by weight, the adhesive strength between the existing hardened body and the permeable concrete tends to decrease, and the cost increases, which is not preferable.

(4) Retarder As the retarder used in the present invention, monocarboxylic acid,
Examples thereof include organic acids such as polycarboxylic acids, oxycarboxylic acids, and amino acids, and metal salts thereof such as sodium, potassium, calcium, and magnesium. Specifically, examples of monocarboxylic acids include formic acid and acetic acid, and examples of polycarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, fumaric acid, phthalic acid, and terephthalic acid. And the like. Examples of the oxycarboxylic acid include heptonic acid, gluconic acid, glycolic acid, malic acid, tartaric acid, citric acid, salicylic acid, and mandelic acid, and the amino acids include ethylenediaminetetraacetate (EDTA) and glutamic acid. , Aspartic acid and the like.

Of these, it is preferable to use oxycarboxylic acids or salts thereof, or polycarboxylic acids or salts thereof. The amount of the retarder to be added is 0.01 to 0.2 part by weight, preferably 0.02 to 0.15 part by weight, based on 100 parts by weight of the cement or the powder mixture containing the cement. If the added amount is less than 0.01 parts by weight, the workability of the paste or mortar becomes poor, which is not preferable. When the addition amount exceeds 0.2 parts by weight, the adhesive strength between the existing hardened body and the permeable concrete decreases.

(5) Shrinkage reducing agent The shrinkage reducing agent used in the present invention is preferably a compound mainly composed of an alkylene oxide adduct of a lower alcohol represented by a chemical formula of RO (AO) _n H. Here, R in the formula is an alkyl group having 1 to 6 carbon atoms. Such groups include methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl, n-pentyl, iso-
-Pentyl group, tert-pentyl group and the like.
A in the formula is one or two alkylene groups having 2 to 3 carbon atoms, such as an ethylene group and / or a propylene group. Further, n in the formula is an integer of 1 to 10.

As a commercially available shrinkage reducing agent mainly composed of an alkylene oxide adduct of a lower alcohol, "AS21" (trade name) manufactured by Taiheiyo Cement Co., Ltd. may be mentioned. The addition amount of the shrinkage reducing agent is 0.5 to 5 parts by weight, preferably 1.0 to 4.0 parts by weight, based on 100 parts by weight of cement or a powder mixture containing cement. If the addition amount is outside the above range, the adhesive strength between the existing hardened body and the permeable concrete is reduced. The shrinkage reducing agent is preferably used in place of a part of water.

(6) Water The amount of water used in the present invention is 20 to 40 parts by weight, preferably 25 to 25 parts by weight, in total with a shrinkage reducing agent, based on 100 parts by weight of cement or a powder mixture containing cement. 3838 parts by weight. If the total amount of water and the shrinkage reducing agent is less than 20 parts by weight, the workability of the paste or mortar deteriorates, which is not preferable. Conversely, if the amount exceeds 40 parts by weight, the adhesive strength between the existing hardened body and the permeable concrete decreases.

The paste or mortar for jointing permeable concrete according to the present invention takes J ₁₄ into consideration in consideration of workability at the time of casting the paste or mortar, and adhesion strength between the existing hardened body and the permeable concrete. Funnel flow time is 3 to 15
Seconds are preferred, and 4 to 12 seconds are more preferred. The kneading method and kneading apparatus for the paste or mortar for permeable concrete joint of the present invention are not particularly limited, and a conventional method and a conventional mixer may be used.

In the present invention, as long as the effects of the present invention are not impaired, an expanding material (lime-based expanding material, calcium sulfoaluminate-based expanding material) and gypsum (anhydrite) are added to the paste or mortar for permeable concrete jointing. , Hemihydrate gypsum,
An inorganic powder composed of dihydrate gypsum or a mixture thereof) and clay (montmorillonite clay such as bentonite and acid clay) and a thermoplastic resin such as an ethylene-vinyl acetate copolymer and an acrylic copolymer are added. That is fine.

Next, a method of joining permeable concrete using the paste or mortar for joining permeable concrete of the present invention will be described. The permeable concrete joining method of the present invention is a first step of casting the permeable concrete joining paste or mortar on an upper surface of an existing hardened body, and the permeable concrete joining paste or mortar. A second step of casting permeable concrete on the upper surface of the permeable concrete joining paste or mortar before the stiffening is performed.

Examples of the existing hardened body include hardened concrete such as concrete pavement and concrete structure, asphalt pavement and the like. Examples of the concrete include ordinary concrete and fiber-reinforced concrete reinforced with various fibers. The method for casting the permeable concrete paste or mortar is not particularly limited, and any conventional method can be used. The thickness of the paste or mortar layer formed after the casting is about 1 to 40 mm, preferably 1 to 10 mm, more preferably 1 to 5 mm from the viewpoint of shortening the construction period and reducing the cost.

In the method for joining permeable concrete according to the present invention, it is preferable to spray a drying inhibitor on the upper surface of the paste or mortar for joining permeable concrete. By spraying the anti-drying agent, especially under conditions that are easy to dry, such as during summer hot weather, even when performing permeable concrete joining work, the thickness of the permeable concrete joining paste or mortar layer can be reduced. For example, the thickness can be reduced to about 1 to 5 mm, and the construction period can be shortened.

As the above-mentioned anti-drying agent, for example, the general formula: RO (AO) _n H shown as an example of the above-mentioned shrinkage reducing agent
(Wherein, R is an alkyl group having 1 to 6 carbon atoms, A is one or two alkylene groups having 2 to 3 carbon atoms, and n is 1 to 1
It is an integer of 0. ), An alkylene oxide adduct of a lower alcohol, polyethylene glycol (weight average molecular weight: about 200 to several thousand), ethylene glycol, diethylene glycol, triethylene glycol,
Polyhydric alcohols such as polypropylene glycol (weight average molecular weight: about 200 to several thousands), propylene glycol, dipropylene glycol, glycerin and the like can be mentioned.

The method for spraying the anti-drying agent is not particularly limited, and any conventional method can be used. The application amount of the anti-drying agent is 100 to 500 g / m ² . The spraying of the anti-drying agent is more effective when the surface of the permeable concrete joint or mortar is slightly dried than immediately after the permeable concrete joint or mortar is cast. It is a target.

In the jointing method of permeable concrete of the present invention, a pretreatment for removing a latence layer or a thin paste layer on the upper surface of an existing hardened body and forming a rough surface having irregularities is performed in advance. preferable. The pretreatment can be performed by, for example, a method of brushing using a wire brush, a method of spraying wet sand, or the like.

The type of permeable concrete that is newly cast on the paste or mortar layer is not particularly limited, and is arbitrary. For example, Japanese Patent Application Laid-Open No. 9-2731
No. 05, "Coarse aggregate and coarse aggregate 100
% Of a paste or mortar having a volume ratio of 30 to 80%, wherein the paste or mortar is 100 parts by weight of cement or a powder mixture containing cement, 0 to 140 parts by weight of fine aggregate, a high performance water reducing agent or high performance. AE water reducing agent 0.5 to 2.0 parts by weight of water-permeable concrete pavement comprising laying the paving kneaded product is water 16-28 parts by weight "and is disclosed in Japanese Patent Kokoku 5-34299" cement concrete 1 m ³ 300-400 kg of Portland cement per cement
0.005 to 0.01 parts by weight of binder and 0.35 to 1 part by weight
~ 0.45 parts by weight of water, and a cement concrete mixture having a mixing ratio of the balance of the aggregate, and kneading the kneaded material on a paved surface with a finisher. Is mentioned.

[0029]

The present invention will be described below by way of examples. [Examples 1 to 7, Comparative Examples 1 to 5] Materials used The following materials were used. 1) Cement; ordinary Portland cement (manufactured by Taiheiyo Cement Co., Ltd.) 2) Blast furnace slag; fine cement 10A (manufactured by Daiichi Cement Co., Ltd.) 3) High-performance water reducing agent: "Mighty 150" (trade name) (Kao) 4) Fine aggregate; Ichihara's Hosomeyama sand (2.5 mm or less in particle size) 5) Retarder; Sodium gluconate (Fujisawa Pharmaceutical Co., Ltd.)
6) Shrinkage reducing agent; "AS21" (trade name) (manufactured by Taiheiyo Cement Co., Ltd.) 7) Water; tap water was used.

2. Mixing and kneading of paste or mortar for jointing permeable concrete The paste or mortar for jointing permeable concrete was prepared according to the combination shown in Table 1 using the above materials. The kneading was performed for 90 seconds using a hand mixer (0.01 m ³ ).

[0031]

[Table 1]

By brushing and washing the upper surface of the hardened φ10 cm concrete cylindrical specimen,
The latence layer on the surface was removed to obtain a rough surface having irregularities. Each paste or mortar shown in Table 1 is cast (applied) thereon, and a paste or mortar layer having a thickness of about 5 mm is formed.
(0 ° C., laboratory experiment), and cured in the air at 20 ° C. for 7 days to prepare test specimens.

As the water-permeable concrete, 80 parts by weight of ordinary Portland cement, 20 parts by weight of blast furnace slag (Fine Cementament 10A), and fine aggregate (Hosameyama Sand from Ichihara) 5
0 parts by weight, 400 parts by weight of coarse aggregate (crushed stone from Ome No. 6), 1.0 part by weight of a high-performance water reducing agent (Mighty 150), and 20 parts by weight of water, were compacted for 20 seconds at a vibration frequency of 3,000 vpm. Was used.

After the preparation of the specimens, the adhesion strength of each specimen was
It was measured according to "JIS A 6909 (finish coating material for construction)".
In addition, regarding the paste or mortar for joining permeable concrete, the workability at the time of application is “○: very good”,
The evaluation was “△: good” and “x: bad”. Furthermore, the paste or mortar splicing permeable concrete J ₁₄
The flow time of the funnel was also measured. Table 2 shows the results.

[0035]

[Table 2]

From Table 2, it can be seen that Example 1 using the paste or mortar for permeable concrete jointing specified in the present invention.
In Nos. To 7, it can be seen that the adhesive strength between the existing hardened concrete body and the permeable concrete is large, and that there is no problem in workability. On the other hand, in Comparative Examples 1 to 5 using mortars other than those specified in the present invention, it can be seen that the adhesive strength between the existing hardened concrete and the permeable concrete is small, or the workability of the mortar is poor.

[Examples 8 to 10] The upper surface of a hardened concrete cylindrical specimen having a diameter of 10 cm was brushed and washed to remove a latence layer on the surface, thereby forming a rough surface having irregularities. Then, the mortar for permeable concrete jointing of Example 1 is cast (applied) thereon, and the thickness is adjusted.
A mortar layer of about 2 mm was formed. Thereafter, the specimens of Examples 8 to 10 were obtained by the following method. In Example 8, at the stage when the surface of the mortar layer was slightly dried (two minutes after the mortar was cast), “AS21” (trade name; manufactured by Taiheiyo Cement Co., Ltd.) was used as a drying inhibitor on the surface of the mortar layer. ) Was sprayed (sprayed) so as to give a spraying amount of 200 g / m ² , and after a lapse of 10 minutes, the same permeable concrete as in Example 1 was poured, and cured in air at 20 ° C. for 7 days.
Specimens were prepared. In Example 9, polyethylene glycol (molecular weight: 200) was used instead of “AS21” at 200 g / m ^2.
Specimens were prepared in the same manner as in Example 8, except that the spray amount was set to be the same. In Example 10, 5 minutes after the formation of the mortar layer, the same permeable concrete as in Example 1 was cast and cured at 20 ° C. for 7 days in the air to prepare a test piece. In any of Examples 8 to 10, the work from the placement (application) of the mortar for permeable concrete connection to the placement of the permeable concrete is as follows.
The test was performed outdoors at 30 ° C. (when the weather was fine). The adhesion strength of the test specimens of Examples 8 to 10 was measured in the same manner as in Example 1. Table 3 shows the results.

[0038]

[Table 3]

From Table 3, it can be seen that Example 8 using an anti-drying agent,
It can be seen that the test specimen of No. 9 has a higher adhesion strength than the test specimen of Example 10 in which no drying inhibitor is used. In addition, the specimens of Examples 8 and 9 had a thickness of the mortar layer of 5 mm, even though the thickness of the mortar layer was as thin as 2 mm, compared with the specimen of the example 1 (see Table 2). It can be seen that the adhesion strength has no significant difference.

[0040]

The paste or mortar for jointing water-permeable concrete of the present invention is intended to improve the adhesive strength when newly casting water-permeable concrete on the surface of an existing hardened body (hardened concrete, etc.). It is extremely useful as a material for. Moreover, according to the method for joining permeable concrete of the present invention, a high joining strength can be obtained because a specific joining paste or mortar is used. In particular, when the anti-drying agent is sprayed on the adhesion surface, a high adhesion strength can be obtained even by using only a small amount of joint paste or mortar.

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C04B 24:32) 103: 20 103: 30 103: 60 (72) Inventor Nobuki Ogura 2-4-2 Daisaku, Sakura City, Chiba Prefecture 2 Central Research Institute of Pacific Cement Co., Ltd. (72) Mitsuo Ishida, Inventor 2-4-2 Daisaku, Sakura City, Chiba Pref. Central Institute of Pacific Cement Co., Ltd. (72) Katsutoshi Ichikawa, 2-4 Daisaku, Sakura City, Chiba Pref. 2. Within the Central Research Institute of Pacific Cement Co., Ltd. (72) Yoshihide Shimoyama 2-4-2 Daisaku, Sakura-shi, Chiba Pref. Inside the Central Research Laboratory of Pacific Cement Co., Ltd. (72) Akira Obata, 2-4 Daisaku, Sakura-shi, Chiba Pref. -2 Central Research Institute of Pacific Cement Co., Ltd. (72) Inventor Tatsuzo Sato 2-4-2 Daisaku, Sakura City, Chiba Prefecture (72) Inventor Shuji Hashimoto 2-11 Tamagawa, Ota-ku, Tokyo −20 Nippon Road Co., Ltd.Technology Research Institute (72) Inventor Etsu Noda Ota-ku, Tokyo Tama River 2-11-20 Nippon Road Co., Ltd. intra-technology Research Institute (72) inventor Nakahara Oiso, Ota-ku, Tokyo, Tama River 2-11-20 Nippon Road Co., Ltd. intra-technology Research Institute

Claims (6)

[Claims] 1. A paste or mortar for use by being interposed between an existing hardened body and a permeable concrete to be passed on to the hardened body, and 100 parts by weight of a cement or a powder mixture containing cement, 0 to 300 parts by weight of fine aggregate, 0.2 to 2.0 parts by weight of water reducing agent (in terms of solid content), and 0.01 to 0.
2 parts by weight, 0.5 to 5 parts by weight of a shrinkage reducing agent, and water mixed so that the total amount of the shrinkage reducing agent is 20 to 40 parts by weight; Paste or mortar. 2. A powder mixture containing the cement, comprising: 50% by weight or more of cement and 50% by weight or less of blast furnace slag powder;
The paste or mortar according to claim 1, comprising at least one inorganic powder selected from fly ash and silica fume. 3. The method according to claim 1, wherein an upper surface of the existing cured body is provided.
The first step of casting the paste or mortar for permeable concrete described, and before the paste or mortar for permeable concrete is hardened, on the upper surface of the paste or mortar for permeable concrete And a second step of casting permeable concrete. 4. The method according to claim 3, further comprising, between the first step and the second step, a step of spraying a drying inhibitor on the upper surface of the paste or mortar for permeable concrete jointing. Joint method of permeable concrete. 5. The method according to claim 1, wherein the drying inhibitor has a general formula: RO (A
O) _n H ( _where R is an alkyl group having 1 to 6 carbon atoms, A
Is one or two alkylene groups having 2 to 3 carbon atoms, n
Is an integer of 1 to 10. 5) The method for joining permeable concrete according to claim 4, which is an alkylene oxide adduct of a lower alcohol or a polyhydric alcohol. 6. The method according to claim 3, further comprising, before the first step, a pretreatment step of removing a latency layer or a thin paste layer on the upper surface of the existing cured body and forming a rough surface having irregularities. A method of joining permeable concrete according to any one of claims 1 to 5.