JP4138992B2 - Porous concrete construction method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a construction technique for porous concrete used for water collection / penetration / storage facilities such as permeable pavement, greening concrete, and rainwater.
[0002]
[Prior art]
Ordinary concrete is filled with mortar between coarse aggregates, but porous concrete is less blended with mortar and imparts water permeability by leaving many continuous voids between coarse aggregates. Concrete that can be greened by filling the gap with soil suitable for plant growth, pavement that gives water permeability so as not to impede the penetration of rainwater into the ground, concrete that can be greened, or It is often used for pipes for collecting and draining. Conventionally, this kind of porous concrete has been manufactured by stirring and mixing all materials such as coarse aggregate, fine aggregate, and cement in the same manner as ordinary concrete. However, the following problems are pointed out in the prior art.
[0003]
[Problems to be solved by the invention]
In other words, porous concrete has little mortar content and coarse aggregates are in a state of biting each other, so it has poor fluidity.For this reason, it can be placed by pumping with a concrete pump like ordinary concrete, or by a vibrator. It cannot be compacted. In addition, mortar and paste do not come out on the surface unlike ordinary concrete, so it is impossible to finish the surface, and it is therefore difficult to finish the surface flat.
[0004]
As described above, since porous concrete is poor in workability, it is difficult to mechanize the work, and the placement of the work has to rely on a lot of work manually. In particular, it is difficult to finish the surface flat, and much labor is required when constructing a large area.
[0005]
Also, if coarse aggregates with a large particle size are used, the load on the mixer increases during kneading and the labor required for manual placement increases, so only coarse aggregates with a particle size of about 20 to 40 mm are used. Can not. And as the particle size of the coarse aggregate is smaller, the continuous voids are inevitably smaller. Therefore, the coarse aggregate tends to be blocked by the intrusion of sand and dust, and the water permeability is likely to be impaired. Moreover, in porous concrete with a small gap, when greening, plants that can be vegetated are limited to herbs with small roots such as grass and ivy, and shrubs such as azalea cannot be planted.
[0006]
The present invention has been made under the circumstances as described above, and the main technical problem is to save the labor by mechanization of construction and to use a coarse aggregate with a large particle size. It is to provide a concrete construction method.
[0007]
[Means for Solving the Problems]
As a means for effectively solving the technical problem described above, the porous concrete construction method according to the present invention forms a coarse aggregate layer having a required thickness by spreading coarse aggregate on the ground, The coarse aggregates are bonded together by spraying cement paste on the coarse aggregate layer to flow down and harden the gaps between the coarse aggregates. In this case, by increasing the spraying amount of the cement paste, excess cement paste fills the lower part of the coarse aggregate layer, so that an impermeable layer is formed.
[0008]
[0009]
[0010]
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 to 5 show an embodiment of a method for constructing porous concrete according to the present invention. In FIGS. 1 and 2, the coarse aggregate 11 is spread and a coarse aggregate layer 11S having a required thickness is formed. The forming process is shown. That is, in this process, first, as shown in FIG. 1, the coarse aggregate 11 is sprinkled on the ground G by a heavy machine 1 such as a backhoe with a required scraping thickness, and this is oscillated as shown in FIG. By rolling with 2 etc., as shown in FIG. 3, a coarse aggregate layer 11 </ b> S whose upper surface is finished almost flat is formed.
[0011]
As described above, since the coarse aggregate 11 is squeezed out and pressed by a machine, significant labor saving is possible, and the coarse aggregate 11 has a relatively large crushed stone having a particle size of 40 mm or more. Etc. can be used.
[0012]
Next, FIG. 4 shows a step of spraying the cement paste 13 on the coarse aggregate layer 11S. The cement paste 13 used here is made by adding water and appropriate amounts of fine aggregate and thickener to the cement and kneading with a mixer to give sufficient fluidity, using a concrete pump or the like. The coarse aggregate layer 11S is uniformly dispersed from above. Since the coarse aggregate layer 11S formed by the above-mentioned spread leveling process has the continuous voids 12 that are intricately interlaced between the coarse aggregates 11, 11,. The spread cement paste 13 flows down the continuous voids 12 while traveling along the surface of the coarse aggregate 11 as shown in black in the figure, and a part of the cement paste 13 contacts the coarse aggregate 11 in the process. Retained in the part.
[0013]
As shown in FIG. 5, the cement paste 13 that reaches the entire coarse aggregate layer 11 </ b> S hardens with time. For this reason, the coarse aggregates 11, 11,... Are bonded to each other via the hardened cement paste 13, and become porous concrete 10 in which a complicated continuous void 12 remains. Further, in the step of spraying the cement paste 13, by making the amount of the cement paste 13 larger than the amount sufficient to cover the surface of the coarse aggregate 11 without excess or deficiency, the excess cement paste 13 is placed below the coarse aggregate layer 11S. As shown in FIG. 5, an impermeable layer 10c made of cement and having a predetermined layer thickness is formed.
[0014]
The strength of the porous concrete 10 increases as the strength of the cement paste 13 bonding the coarse aggregates 11 increases. Since the strength of the cement paste 13 increases as the water cement ratio decreases, it is effective to reduce the water mixing ratio (reduce the water cement ratio) in order to increase the strength of the porous concrete 10. In general, the smaller the water-cement ratio, the greater the load during kneading with the mixer. However, the load on the mixer is significantly smaller than when mixing coarse aggregate with cement paste as in the conventional method. Therefore, even if the amount of water is reduced, it can be sufficiently kneaded and the strength of the porous concrete 10 can be increased.
[0015]
Further, the thickness of the cement paste 13 that adheres to the coarse aggregate 11 in the process of flowing down the continuous void 12 increases as the viscosity increases, and the volume of the continuous void 12 decreases as the adhesion thickness increases. Become. For this reason, the strength of the porous concrete 10 and the size of the continuous voids 12 can be appropriately set by adjusting the amount of the thickener added during the production of the cement paste 13.
[0016]
As shown in FIG. 6, the porous concrete 10 constructed by the above-described process can be greened by filling the continuous void 12 with a soil component 14 or the like. And since this porous concrete 10 uses the coarse aggregate 11 with a large particle size, the filling volume of the soil component 14 by the continuous space | gap 12 necessarily becomes large, it is not restricted to turf, ivy, etc., For example, a shrub P such as an azalea can be planted.
[0017]
The porous concrete 10 which is applied by the above-described process, the one for having a large continuous void 12 by using a large coarse aggregate 11 of particle size, clogging intrusions such as sand and dust hardly occurs .
[0018]
[0019]
[0020]
[0021]
Moreover, since the lower part of the porous concrete 10 has a water-impermeable layer 10c, rainwater or the like that has entered from the upper part is stored in the continuous gap 12, or applied to a water collecting means or a water channel like a U-shaped groove or a fume pipe. You can also In this case, organic and inorganic pollutants contained in the water slowly flowing in the continuous voids 12 due to the biochemical action of microorganisms and various bacteria attached to the surface of each coarse aggregate 11 and breeding. Since it is decomposed, it can have a function of promoting natural purification of water.
[0022]
[0023]
[0024]
[0025]
[0026]
【The invention's effect】
According to the construction method for porous concrete according to the present invention, since a considerable part of the construction such as the leveling work of the coarse aggregate can be mechanized, the labor can be saved. Also , since it has a water-impermeable layer at the bottom of the porous concrete, it is possible to store rainwater that has entered from the top in a continuous gap, or to apply it to water collection means and waterways, using coarse aggregate with a large particle size Therefore, an excellent effect is realized that clogging is difficult and planting of a shrub with a relatively large root is possible.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is an explanatory diagram showing a step of scooping out coarse aggregate in an embodiment of a porous concrete construction method according to the present invention.
FIG. 2 is an explanatory diagram showing a step of rolling a coarse aggregate in the embodiment .
FIG. 3 is a partial cross-sectional view showing a coarse aggregate layer formed in the embodiment .
FIG. 4 is an explanatory diagram showing a step of spreading cement paste on a coarse aggregate layer in the embodiment .
FIG. 5 is a partial sectional view showing porous concrete constructed according to the embodiment .
FIG. 6 is a partial cross-sectional view showing a state where planting has been performed on porous concrete constructed according to the embodiment .
[Explanation of symbols]
10 Porous concrete
10c Impermeable layer 11 Coarse aggregate
11S Coarse aggregate layer
12 Continuous void 13 Cement paste

Claims (1)

A step of spreading a coarse aggregate on the ground and forming a coarse aggregate layer of a required thickness;
It comprises a step of bonding the coarse aggregates by spreading cement paste on the coarse aggregate layer and flowing down and hardening the gaps between the coarse aggregates .
A method for constructing porous concrete, wherein a portion of the cement paste flowing down the void fills the lower part of the coarse aggregate layer to form an impermeable layer .

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