JPS59206502A - Production of water pervious cement concrete construction - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing permeable cement concrete constructions.

In recent years, as the trend of urbanization has progressed, its negative effects have become noticeable in many areas.

This is also the case with asphalt pavement, concrete pavement, and various types of buildings that impermeable water on the ground surface.Rainwater, which had previously permeated naturally into the soil, no longer permeates, resulting in a rapid decrease in groundwater. Land subsidence, slowing of tree growth, changes in the ecology of subsoil organisms, and river flooding caused by torrential rains that occur in various places every year are becoming major social problems, and we need solutions to these problems. has become an urgent task.

Therefore, the emergence of water-permeable pavement is strongly desired, and water-permeable asphalt is conventionally known. However, water-permeable asphalt is not always satisfactory because it has poor water permeability and water content, the asphalt melts and becomes clogged due to sunlight, worsening water permeability, and its strength changes over time. Ta. On the other hand, water permeable concrete using cement concrete cannot be made to have both sufficient water permeability and strength, and so far, no practical water permeable concrete has been known.

As a result of intensive research to make cement concrete structures water permeable and at the same time usable as actual road surfaces, the inventors have discovered that cement concrete structures made with a specific composition have excellent water permeability. The present invention was completed based on the discovery that the material has excellent properties and strength, and that the strength and water permeability change very little over time. This must be said to be truly surprising, considering that it has previously been thought that it was impossible to produce concrete with satisfactory water permeability.

That is, the present invention provides cement concrete mixture 1-3.
The present invention provides a method for producing a 500-400 to 7 Portland cement, a binder of 0.008 to α04 parts by weight (solid content) per 1 part by weight of cement, and a 0.3 aqueous cement concrete construction.

In the present invention, the weight ratio of No. 7 crushed stone and sandy aggregate should be 5:95 to 20:80. As the amount of sand tends to decrease, the strength tends to decrease, so a ratio of 5:95 is suitable for pavements for sidewalks, and a ratio of 10F90 or higher is usually adopted for pavements for light traffic. 15:8
At a ratio of 5, typically the compressive strength σ7=115 K
g/cm". On the other hand, if the amount of sand is increased beyond the upper limit, water permeability will deteriorate. Also, a part of the above-mentioned aggregate, preferably 10 to 50 g/cm, can be mixed with No. 6 crushed stone (particle size 16 to 50 g/cm). 5 simple)
It can also be replaced with . In this case, it is preferable in that the strength increases to some extent (σ7=125 to 140 k'4/cm2), but it has the drawback that the appearance is not good because large crushed stones of No. 6 are mixed in crushed stones of No. 7.

The amount of Portland cement is 1tn”a+)300-400 of the entire cement-concrete mixture including water.
Kg, preferably 2 to 320 to 570. If the cement needle is passed more than 400 Kf, the strength will be increased, but the water permeability will be poor and it is not suitable for the purpose of the present invention. On the other hand, if the amount of cement is less than 500 Kf, the strength will be insufficient.

0.008 to 0040 per part by weight of cement
Parts by weight of binder are added, preferably from 0.015 to 0.05 parts by weight. As binders, it is possible to use all binders which are normally known for VC addition to cement mortars. Natural or synthetic rubber such as S
B.R.

NBR, acrylic resin, epoxy resin, etc. can be used, and these binders are usually added as an emulsion. The amount of binder mentioned above indicates the amount of resin in the emulsion as a solid content. For example, commercially available SBR latex binder (JS
If R+-Max-Par, Japan Synthetic Rubber Co., Ltd. (solid content 0.45%) is used within the above range, an improvement in bending strength of about 10 to 60 inches can be obtained, but if the bending strength is increased beyond the above range, If used for this purpose, the water permeability will be greatly reduced, which is not preferable. When Ashida acrylic binder (X-5142, manufactured by ANR Co., Ltd.) is used, the bending strength can be improved by 60 to 90%. 1j2 with epoxy binder
A curve of 0 to 40% generally does not improve strength, and epoxy binder has the drawback that workability is generally poor.

The amount of water is 0.50 to 045 parts by weight, preferably 055 to 040 parts by weight, per 1 part by weight of cement. If the amount of water is more than the upper limit, the water permeability will be poor, while if the amount is less than the lower limit, sufficient kneading cannot be achieved.

In addition to the above-mentioned essential formulations, it is also possible to add customary additives to cement concrete, such as red iron oxide for coloring, in an amount of 5 to 5% based on the amount of cement.

In the present invention, cement concrete structures refer to pavements for sidewalks, parking lots, etc., as well as water-permeable layers built on top and bottom of clothing to improve drainage, and molded blocks used for these, which require water permeability. It covers all general cement concrete structures.

A characteristic feature of the permeable cement concrete construction according to the invention is its high porosity. porosity of 10-50%,
Preferably porosity of 15 to 25% can be obtained according to the invention. Therefore, it is superior to asphalt permeable pavement in that temporary water retention through these voids and subsequent water permeation proceed extremely quickly. It also has the advantage of not clogging, aging, or melting under high temperatures unlike asphalt pavement. Another good point is that even if small pieces of earth and sand are carried by shoes or tires and accumulate on the surface of the structure, when it rains, they will pass through the gaps and be washed away, so there is no need for cleaning.

The hydraulic conductivity is 10-'-10-' cm/sec, typically 10-1 to 10''3crn/5eC-
orders are obtained. 10-' at 20% porosity
On the order of cm/sea, the porosity is 10-2
Indicates the water permeability coefficient in cm/see.

It must be noted that while the water-permeable cement concrete structure of the present invention exhibits large porosity and water permeability as described above, it also has sufficient strength for practical use. The compressive strength of the permeable cement concrete pavement of the present invention is 2 [
] 0-400Ky/cm" (1 week strength, 20℃ constant temperature water curing), bending strength is 20-30Ky/crn2 (4
1 week strength, curing in constant temperature water at 20°C).

Based on these values, the applicability of this pavement is sidewalks, parking lots,
It can withstand not only sports fields but also B traffic as shown in the traffic classification of concrete pavement guidelines.

The implementation of the present invention will be explained in the case of pavement.

Pavement cross sections must be designed taking into consideration rainfall amount, rainfall intensity, load strength on the pavement surface, water storage capacity of the pavement, bearing capacity of the subgrade, and permeability of the subgrade, etc. As a guide, 10crn for sidewalks, 15crn for parking lots, playgrounds, etc.
(7) Light traffic roads can be reinforced by 15cb. It is also possible to install ropes with strong tensile strength (glass fiber netting, etc.) on the pavement surface.

The construction of permeable cement concrete pavement was carried out using general equipment. The concrete is mixed at a concrete plant, transported to the site using a truck mixer or a dump truck, and laid flat on the roadbed or roadbed using a finisher to a predetermined thickness and quality.

In the present invention, an example of a preferable mixing ratio of cement concrete 1/mixture is as follows: Weight ratio of sandia crushed stone - 151es Cement 350 xy/□S Binter A5% emulsion Toshi, 0.04 water emulsion to cement 04 for Semenodo, including the water contained in it.

In summary, the present invention has surprisingly made it possible to manufacture a practical water-permeable cement concrete structure, which was previously thought to be impossible.

Claims (1)

[Claims] t Cement concrete mixture 1 m3a D, 60
0-400 K9 Portland cement, cement 1
o, o o a to 0.04 parts by weight to i parts by weight of binder, 0.5 to 0.45 parts by weight of water, and the remainder in an IT ratio of 5:95 to 20:80. A method of making a permeable cement concrete structure by wet bulbing an aggregate consisting of sand and No. 7 crushed stone, pouring or pouring the resulting mixture, and allowing it to harden. 2. The method according to claim 1, wherein the ratio of sand to No. 7 crushed stone is 10:90 to 15:85. 5. 0.015 to 0.06 per 1 part by weight of cement
2. The method of claim 1, using parts by weight of binder. 4. The method according to claim 1, in which 0.55 to 0.40 parts by weight of water is used per 1 part by weight of cement. 5. The method according to claim 1, wherein the cement is used in an amount of 320 to 570.