JPH04360903A - Crack-free construction of water-permeable cement pavement - Google Patents

Abstract

PURPOSE:To make the admistration of mixtures before hardening easier and construct pavements having very few cracks. CONSTITUTION:At least color granulated slag and cement as main materials are mixed with a methyl cellulose or acrylic resin admixture to form a paving composition, and the paving composition is mixed with water to obtain a mixture. The mixture is placed on a specified position and compacted into a swirl form.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-permeable cement paving material composition that is applied by compaction in the civil engineering and construction fields.

0002

BACKGROUND OF THE INVENTION Asphalt and concrete are the main materials used for paving, but asphalt is limited to black in color, and concrete has a problem in that it has no water permeability. Therefore, recently, water-permeable cement-based paving material compositions have been developed and are being used. Commonly used water-permeable paving materials include those made by granulating slag produced in steel mills, sintering the slag, and press-molding it with thermosetting resin, and open-grained asphalt concrete. There are also methods in which cement and admixtures are added to granulated slag, kneaded with water, and then compacted to form a pavement (Japanese Unexamined Patent Application Publication No. 63-233103, Japanese Unexamined Patent Publication No. 2-133350, etc.). Japanese Patent Publication No. 63-233
The paving material described in Publication No. 103 is made by adding a dye or pigment and an alkaline aqueous solution of a polyvinyl alcohol derivative having a SiO2 reactive group to granulated slag produced in a steel mill, and then kneading the mixture.
In this method, colored slag is obtained by drying, and cement, a hardening agent, and water are added to the slag, kneaded, and then placed and rolled to form a pavement. The rolling compaction was performed by moving the surface of the poured body back and forth in a U-shape.

0003

[Problems to be Solved by the Invention] The above-mentioned granulated slag-based paving materials have a problem in that they tend to crack after construction. In addition, for kneaded materials used as water-permeable paving materials, the range of the amount of mixing water that is appropriate for ensuring the water permeability of the pavement is generally very narrow, and its management requires time and skill. In particular, in order to ensure water permeability, the amount of kneading water had to be reduced, resulting in low initial strength and easy cracking, which was a major problem.

0004

[Means for Solving the Problems] The present invention has been made to solve the above problems, and water permeability is ensured by adding a methylcellulose-based or acrylic-based admixture and devising a compaction method. This was done after discovering that it was possible to increase the initial strength and greatly reduce the occurrence of cracking.

[0005] That is, the present invention provides a paving composition comprising at least colored granulated slag and cement as main materials and water added to a paving material composition containing a methylcellulose-based or acrylic-based admixture. The present invention relates to a method for constructing a water-permeable cement pavement, which is characterized by rolling this material into a spiral shape.

Colored granulated slag is obtained by coloring granulated slag particles with a dye or pigment and coating them with a polyvinyl alcohol derivative having a SiO2 reactive group. The polyvinyl alcohol derivative having a SiO2 reactive group consists of a structural unit represented by the following formula [I].

[0007]

[Chemical formula 1]

(In the formula, X, X1, and X2 have 10 carbon atoms.
The following alkyl groups, hydrogen atoms, potassium atoms, sodium atoms, and ammonium groups are shown, where l, m, and n are 45.0 to 99.8% of the total polymerization degree (l+m+n), and m is 0 to 35. 0%, n is 0.2-20%. )

[0009] Degree of polymerization (l+m+n) is 300 to 10,0
It is 00. The preferred number of carbon atoms in the alkyl group is 1 to 8
It is. The amount of polyvinyl alcohol derivative added to the slag is 0.
．． 05 to 10% by weight is preferred.

Dyeing and pigments include organic or inorganic pigments,
Although any dye can be used, inorganic pigments are preferred, and those that are weather resistant, acid resistant, and alkali resistant are preferred. The appropriate amount of addition is generally about 0.3 to 20% by weight based on the slag. This amount may be outside this range depending on the type of pigment cement, the amount of cement, and the desired color value.

Colored granulated slag can be formed by adding and mixing a dye or pigment and an alkaline aqueous solution of the above polyvinyl alcohol derivative to granulated slag powder. By this mixing, the S of the derivative is
The iO2 reactive group chemically reacts with the SiO2 group on the surface of the slag particles and is irreversibly bonded to the SiO2 group. The dye and pigment may be added at the same time as the polyvinyl alcohol derivative, or may be added and mixed to the granulated slag powder in advance. An ethylene copolymer emulsion or synthetic rubber latex that is compatible with the alkaline aqueous solution of the polyvinyl alcohol derivative can be added to the aqueous alkaline solution of the polyvinyl alcohol derivative. Particularly effective is methacrylic acid methyl ester and acrylic acid butyl ester copolymer emulsion, with COOH and OSO3 in the copolymer.
It contains H, SO3H, or their Na, K, or ammonium salts, and has a molecular weight of about 100,000 to 1,500,000. Emulsion particle size is 0.15±0
．． 02μ, pH 8.0±0.5, concentration 40-50
% by weight is appropriate. The amount added is expressed as solid weight.
5 to 100 per part by weight of polyvinyl alcohol derivative
Parts by weight, preferably 30 to 80 parts by weight. Further, a higher fatty acid alkali salt can be added. This higher fatty acid alkali salt is a saturated or unsaturated fatty acid having 10 or more carbon atoms, and any of stearic acid, oleic acid, tall oil fatty acid, rosin acid, etc. can be used. The amount added is 0.1 to 50% by solid weight, preferably 0.2 to 30% by solid weight, based on the polyvinyl alcohol derivative containing a SiO2-reactive functional group. Details of the method for producing colored granulated slag are described in JP-A-63-233103.

[0012] The cement is usually Portland cement, but white cement or blast furnace cement can also be used if necessary. The appropriate mixing ratio is about 15 to 60 parts by weight per 100 parts by weight of the colored granulated slag.

[0013] The methylcellulose-based or acrylic-based admixture preferably has a high water retention property. Examples of methylcellulose include hydroxypropylmethylcellulose and hydroxyethylmethylcellulose. Acrylic admixtures include polyacrylamide and the like. The appropriate amount to be added is 0.05 to 0.2 parts by weight for methylcellulose-based admixtures, preferably 0.1 parts by weight for 100 parts by weight of kneading water, and 0.05-0.2 parts by weight for acrylic-based admixtures. .05～
Approximately 0.1 part by weight is appropriate. If it exceeds 0.2 parts by weight, the water evaporation prevention effect and the initial strength enhancement effect will be increased, but the water permeability of the cured product will be extremely reduced or completely eliminated. Furthermore, if the amount added is less than 0.05 part by weight, the effect will be small.

The paving material composition of the present invention preferably contains hard sand. The hard sand may be crushed stone, natural sand, air-crushed slag, etc., and one having a particle size of about 0.3 to 2.5 mm is suitable. The reason for limiting the particle size to 0.3 to 2.5 mm is that if the maximum particle size exceeds 2.5 mm, the voids between the particles will be filled with more granulated slag than necessary, and compaction performance will improve. This is because water permeability is extremely reduced. Furthermore, the surface of the compacted pavement becomes rough, which is not aesthetically pleasing. On the other hand, particles with a particle diameter of 0.3 mm are not preferable because the voids between the particles of the granulated slag are filled with hard sand more than necessary, resulting in an extremely low water permeability.

Hard sand having such a particle size may be selected from those existing in nature, or may be obtained by classification by known means. Hard sand can be colored and used in the same manner as the colored granulated slag described above. The appropriate mixing ratio of hard sand is about 10 to 40 parts by weight, preferably about 15 to 25 parts by weight, per 100 parts by weight of colored granulated slag.

The expansible admixture is mixed to prevent cracks caused by drying shrinkage of the cured water-permeable pavement, and may be either lime-based or auin-based. The appropriate amount of addition is 5 to 10 parts by weight per 100 parts by weight of cement.

[0017] In addition, various additives that are added to concrete and the like can be added as necessary. For example, as a cement hardening accelerator, an alumite calcined body or a mixture thereof with Al2O3, CaSO4, etc. can be used. The amount added is 1 to 20% by weight, preferably 5 to 15% by weight of the cement. In addition, water reducing agents, antifreeze agents, etc. can be added. Kneading water amount is 1m3 of kneaded material
per unit, 170 to 190 kg/m3 is appropriate.

A major feature of the construction method of the present invention is that the above-mentioned kneaded material is rolled into a spiral shape. If the pavement is circular, it may be rolled in a circular spiral shape, and if it is square, it may be rolled in any form such as a circular spiral shape or a rectangular spiral shape. A compaction machine such as a vibroplate may be used as the equipment for compaction, and the compaction conditions may be the same as conventional ones.

[0019]

[Operation] One of the causes of cracks in conventional pavement is a lack of initial strength. In other words, in order to form a water-permeable pavement, the amount of water mixed must be extremely small, and as a result, during high temperatures in midsummer or on dry, windy days, water evaporates from the surface of the mixed material, causing cement to deteriorate. Initial strength tends to be insufficient due to lack of moisture necessary for hydration. In the method of the present invention, a methylcellulose-based or acrylic-based admixture is added to the paving material composition to increase water retention, suppress water evaporation, and secure the water necessary for hydration of cement.

Another cause of the cracks is the rolling compaction method, which involves moving the compaction machine back and forth in a U-shape. That is, since cracks that occur along the rolling direction occur several months after construction, it was initially unclear that the cause was due to rolling. Currently, it is believed that the cause of this cracking is that when the compaction machine returns from the first compaction, the composition of the compacted paving material loosens at the edges due to re-vibration of the compacted paving material. Thought. Therefore, in order to reduce this loosening, rolling pressure is applied in a spiral shape to disperse the occurrence of cracks, thereby reducing the number of cracks.

[0021]

【Example】

(1) Preparation of aqueous alkaline solution of polyvinyl alcohol derivative SiO2 reactive group-containing polyvinyl alcohol derivative 2.5
Part by weight Caustic soda
Add 0.07 parts by weight of water
100 parts by weight However, in the SiO2 reactive group-containing polyvinyl alcohol derivative, X, X1, and X2 in the above formula [I] are Na, and the degree of polymerization is 2.
000, of which l was 1700, m was 220, and n was 80.

[0022] The mixture of the above formulation was heated at 80°C and 20~30R.
A clear viscous liquid was obtained by stirring with PM for 1.5 to 2 hours. Above treatment liquid

200 parts by weight 40% methyl methacrylate-butyl acrylate copolymer emulsion 450 parts by weight
5% tall oil saponification liquid
300
Part by weight 5% paraffin emulsion

50 parts by weight

1000 parts by weight

0023
] The above mixture was stirred at 35 RPM, pH 8.2, viscosity (25°C) 50c. p. The following emulsion was obtained as an alkaline aqueous solution of a polyvinyl alcohol derivative.

(2) Preparation of colored granulated slag Slag
1250g (particle size 0.5-2.5mm)
red pigment
42g Aqueous solution of silica reactant of the present invention
20g water
50g
The above mixture was stirred for 3 minutes and air-dried to obtain a colored granulated slag with a water content of 10% by weight and a specific gravity of 2.6.

(3) On-site construction test Ordinary Portland cement was added to the above colored granulated slag.
Expansive admixture ("Expan", Onoda Cement Co., Ltd.)
), methylcellulose-based admixture (Himetrose
90SH-4000'' (manufactured by Shin-Etsu Chemical Co., Ltd.) and water were added in the proportions shown in Table 1, and kneaded with a mortar mixer to obtain a kneaded product.

[0026]

[Table 1]

Each of the above-mentioned kneaded products was poured into a 3 m x 4 m rectangle with a thickness of 4 cm, and was rolled by moving it in a spiral or reciprocating manner using a vibro plate. When each pavement was observed two months later, the occurrence of cracks was as follows.

[0028]

[Table 2]

[0029]

[Effects of the Invention] By the construction method of the present invention, a pavement with very few cracks can be constructed. Moreover, it is easy to manage the kneaded material before solidification.

[Brief explanation of the drawing]

FIG. 1A is a plan view showing a rolling form of the present invention, and FIG. 1B is a plan view showing a reciprocating rolling form.

[Figure 2] Figure 2A is a plan view showing cracks in a pavement rolled in a spiral shape using a kneaded material containing a methylcellulose admixture, and Figure 2B is a plan view showing cracks in a pavement rolled back and forth. FIG. 3 is a plan view showing the situation.

[Fig. 3] Fig. 3A is a plan view showing cracks in a pavement compacted in a spiral shape using a kneaded material without the addition of methylcellulose admixtures, and Fig. 3B is a plan view showing cracks in a pavement compacted in a reciprocating manner. FIG. 3 is a plan view showing the situation.

Claims (1)

[Claims] Claim 1: A kneaded material made by adding water to a paving material composition containing at least colored granulated slag and cement as main materials and containing a methyl cellulose-based or acrylic admixture is poured into a predetermined area, and then the mixture is vortexed. A construction method for a permeable cement pavement characterized by compaction in a shape