JP2003184025A - Method for constructing porous concrete slope face - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for constructing a river revetment, a bank slope surface, etc., which gives consideration to vegetation and ecosystem, by porous concrete excellent in permeability. <P>SOLUTION: According to the method, a concrete material is sequentially spread on the slope surface from a slope conveyor 10 which is erected on the slope along a sloping direction and capable of traveling in a slope longitudinal direction. Then, the concrete material spread on the slope surface is sequentially oscillated and rolled by a finisher 30 which follows the slope conveyor 10 and includes a screw spreader 31 and a rolling cylinder 35 which are movable along the sloping direction, to thereby form a unit porous concrete layer having a predetermined porosity. Then, the unit porous concrete layer is laminated according to design specifications, to thereby construct a porous concrete slope face having a predetermined layer thickness. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a porous concrete slope, and a porous concrete slope ensuring a predetermined porosity that enables the construction of slopes such as river revetments and embankment slopes in consideration of vegetation and ecosystem. Regarding how to build.

[0002]

2. Description of the Related Art Cement concrete has contributed significantly to the development of social life and the economy as a leading role in infrastructure development in the 20th century. However, it cannot be denied that it can be cited as one of the protagonists of the harmful effects of urbanization, such as the concrete jungle. In this way, cement concrete is a typical material that has both a "positive heritage" of constructing structures based on its strength and durability and a "negative heritage" of natural environment destruction. is there. It is said that the 21st century is the age of restoration of these negative heritage. From the viewpoint of restoration of such negative heritage, the river law was revised in 1997, and in addition to conventional flood control and water use, water quality and green conservation, amenity of river space, etc. It was decided to be launched. Porous concrete is one of the things that is drawing attention in this situation. This porous concrete is concrete in which a relatively large void is added to cement concrete, and by utilizing this void to facilitate plant entry, river revetment can be greened. Recently, plans for making natural rivers using this technology are increasing. In addition, the weeding work and the treatment of the embankment structures such as roads and railroad tracks are becoming a heavy burden for facility managers, and the use of porous concrete has been drawing attention to these as well. There is.

[0003]

By the way, most of the corresponding technologies in the present situation are porous concrete blocks, which are factory products, and the block products manufactured in advance at the factory are carried to the site and laid on the slope of the river. It is a thing. These have no special problems in terms of quality,
It has problems in economy and workability.

Porous concrete structures cast on site are also constructed. As the construction method is described in "Guide for Porous Concrete River Revetment Method" (Foundation: Center for Advanced Construction Technology), the concrete material that constitutes the porous concrete that has been delivered to the site (hereinafter, this specification Then, the concrete material of the composition that constitutes the porous concrete is referred to as the porous concrete material, and the hardened concrete that achieves the porosity of the specified porosity or more by placing the porous concrete material is simply referred to as the porous concrete. It is carried out by throwing it into the target slope, laying it out with a backhoe and manually, and then rolling the surface with a bucket of the backhoe. This construction method has problems in terms of quality such as insufficient strength and uneven voids. In addition, there are problems in terms of workability and economy, and establishment of a full-scale machine construction method on the slope to solve these problems has been awaited.

Regarding porous concrete pavement on a flat surface (flat land) such as a road or a plaza, for example, a machine construction technique (patent No. 1966352) using an asphalt finisher developed by the present applicant effectively penetrates rainwater in the pavement field. It is widely used as an environmental protection technology. However, this technology does not consider application to the construction of slopes such as river revetments.

On the other hand, regarding the mix of concrete constituting the porous concrete, since the completed porous concrete has a large number of continuous voids, the surface area thereof is usually several tens to several hundred times that of concrete. For this reason, when this porous concrete is used as a vegetation revetment, there is concern that the high PH of cement free lime and the permeated rainwater may adversely affect the plants. No. 54,306) has been developed.

By the way, the characteristic of porous concrete is that a sufficient volume of voids is left between the aggregates of the concrete after it has been cast into a predetermined volume. The desired void does not exist. In other words, in the porous concrete of the present invention, the mixing design and the construction method are closely related,
This point is very different from ordinary concrete construction methods.
For example, when assuming 25% of voids in 1 m ^{3 of} concrete, the total volume of mixing elements such as aggregate and cement is 0.
It is 75 m ³ , and if this concrete is 1 m ³ after completion of pouring, porous concrete with 25% voids remaining can be obtained. Therefore, if the compaction energy at the time of pouring is large, the concrete becomes denser than expected and the volume after completion is reduced, that is, the voids are reduced and the strength is increased. On the other hand, if compaction is insufficient, the voids increase and the strength decreases, so porous concrete of a specified standard cannot be obtained. In this way, porous concrete can obtain a predetermined product only when its composition and construction method are closely related.

The peculiarity of the porous concrete material is that it has almost no fluidity in the fresh concrete state as compared with ordinary concrete. Therefore, there is a problem in that the compaction effect cannot be obtained by the conventional compaction means such as a rod-shaped vibrator. For these reasons, it has been earnestly desired to develop a porous concrete method capable of constructing slopes such as a new river bank and embankment slopes, which replace conventional techniques. Therefore, the present invention introduces vibration and roller compaction at the time of finishing a concrete surface, and performs multi-layer casting by laminating unit concrete layers to obtain a porous concrete that is homogeneous and has a predetermined performance over the entire layer. To realize the construction of the slope.

[0009]

In order to achieve the above-mentioned object, the present invention is constructed so that the concrete material is continuously sprinkled on the slope from the material spouting means which is installed along the slope direction and can run in the longitudinal direction of the slope. The concrete material sprinkled on the slope is continuously vibrated in the slope direction by the slope finishing means moving along the slope direction, following the material spraying means, and roller rolling is performed to obtain a predetermined porosity. It is characterized in that a unit porous concrete layer is formed, and the unit porous concrete layer is laminated and constructed to construct a porous concrete slope having a predetermined layer thickness.

At this time, the slope finishing means includes a screw spreader and a compaction cylinder, and the screw spreader is used in consideration of a predetermined excess of the concrete material on the slope with respect to the layer thickness of the unit porous concrete layer. It is preferable to form the unit porous concrete layer having a predetermined layer thickness by the vibration applied by the roller compaction cylinder and the roller roller compaction action after the uniform thickness is scraped.

The unit porous concrete layer has a layer thickness of 8 to
It is preferably 20 cm. Further, in the cast concrete having a predetermined porosity, the porosity and the strength suitable for the porous concrete can be obtained by adjusting the concrete composition such that the mortar amount per unit volume is 130 to 280 l / m ^3. Can be prepared. The water cement ratio (W / C) at this time is preferably in the range of 20 to 45%.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a method for constructing a porous concrete slope according to the present invention will be described below with reference to the accompanying drawings.

[Structure of Slope Placing Device] In order to realize the present invention, a slope having a predetermined design slope by cutting, embankment, etc. (in the present specification, a sloped ground surface, concrete, etc. We have developed a concrete slope pouring device for constructing porous concrete. FIG. 1 is a layout and construction status diagram of a slope driving apparatus used in the present invention, and FIG. 2 is a side view of the slope driving apparatus. The slope driving device is composed of two independent devices, a slope conveyor 10 and a cylinder finisher 20. The slope conveyor 10 and the cylinder finisher 20 are
Steel frames 11 and 21 having rigidity capable of being installed along the slope 1 to be cast are the main structural materials, and support legs 12 composed of lifting cylinders on both sides of the frame upper portions 11a and 21a and lower portions 11b and 21b. Running wheel 1 supported by 22
3,23 are provided. And on the rail 2 laid along the longitudinal direction of the slope 1 at the shoulder and the butt,
The slope conveyor 10 precedes, and the cylinder finisher 20 follows the slope conveyor 10 at predetermined intervals and can be self-propelled by an engine (not shown) mounted. In addition, the steel frames 11 and 21 can be united to have a predetermined installation length by connecting a plurality of unit members having a unit length according to the pave width. Alternatively, a fixed length frame structure is assembled according to the construction span, and the slope conveyor 10 and the cylinder finisher 2 are assembled.
You may make it mount 0. Further, it is also possible to provide a placing device integrally provided with a concrete spraying function, a scraping leveling function, and a rolling compaction function in an integrated structure frame. In addition,
As for the traveling method, any method other than the rail traveling method described above, such as a tire traveling method that does not use rails, can be applied as long as the steel frames 11 and 12 can travel stably.

The slope conveyor 10 has a structure shown in FIGS.
As shown in (a), the belt conveyor 14 is incorporated along the frame 11 so that the belt surface is exposed from the upper surface. Further, a charging hopper 15 is provided on the upper part, and the porous concrete material C can be supplied from the charging hopper 15 onto the belt conveyor 14. Further, on the side surface, a spreading hopper 16 movable along the frame 11
Is attached. The porous concrete material C on the belt conveyor is passed through the hopper 16 for spreading the slope 1
It can be sprinkled on top with an approximate width and thickness. At this time, since the drop height from the spraying hopper 16 is constant, the porous concrete material can be stably sprayed. Further, the height of the sprinkling hopper can be changed according to the thickness of the unit porous concrete layer to adjust the density when sprinkling the concrete material due to the difference in drop height.

FIG. 3 is a schematic layout diagram showing a schematic structure of a finisher portion 30 which is a drive portion of the cylinder finisher 20. The entire finisher portion 30 can move up and down in the direction of the slope along a traveling guide rail (not shown) provided along the lower chord member of the frame 21 of the cylinder finisher 20. Inside the finisher portion 30, as shown in the schematic configuration of FIG. 3, a screw spreader 31 arranged substantially coaxially and a rolling cylinder 3 are provided.
5 and 5 are arranged. The screw spreader 31
In this embodiment, the rotating shaft 3 has a diameter of about 25 cm and a length of 60 cm.
It rotates through the drive transmission portion 33 connected to the two ends,
As shown in both figures, the porous concrete material sprinkled on the ground surface 1 or on the first unit porous concrete layer C ₁ is scratched to the set approximate width and height (concrete thickness). Can be leveled. The compaction cylinder 35 is arranged substantially coaxially with the screw spreader 31, and in the present embodiment, has the same diameter as the screw spreader 31 and a length of 122 cm. The compaction cylinder 35 has a vibration (vibration) function and a roller compaction function, and can perform a predetermined compaction operation on the porous concrete material C when the roller travels on the concrete placing surface. Note that, in FIG. 4, the screw spreader 31 and the compaction cylinder 35, which are coaxially located, are separated from each other in the direction of the slope for the purpose of explanation, and the vibration by the compaction cylinder 35 and the roller compaction operation make the concrete surface C leveled. The state of progressing later is schematically shown.

In this embodiment, as a vibrating function, a vibrating body (not shown) attached to the cylinder rotary shaft 36 causes a predetermined vibration (vibration) when the cylinder rotary shaft 36 rotates. Rolling cylinder 3
The frequency of 5 is preferably 1,000 to 5,000 vpm. Further, the roller rolling function is performed by the reduction gear box 7
This is achieved by decelerating the cylinder rotation via.
The rotation speed of the compaction cylinder 35 is preferably in the range of 50 to 500 rpm for securing the strength, density, and voids of the porous concrete after compaction finishing. When the rotation speed is lower than this range, the surface finish becomes rough and the strength and density decrease and there are too many voids. Conversely, when the rotation speed is higher than this range, the surface finish becomes too dense and it is not suitable for rooting of plants. Is too small to obtain the desired performance. In order to achieve appropriate porosity and strength during construction, the layer thickness of the unit porous concrete layer C _i depends on the relationship with the design thickness, but in this embodiment it was about 10 cm. The range is preferably 8 to 20 cm. When it is 8 cm or less, the compaction effect is good and the strength is sufficiently obtained, but the porosity may be less than the specified value. On the other hand, if it is 20 cm or more, the specified strength may not be obtained.

[Concrete sprinkling-laying-leveling-finishing process] The flow of each work from the sprinkling process of the porous concrete material to the finishing process by the above-described slope placing device will be described with reference to FIG. First, the porous concrete material C is spread by the slope conveyor 10 arranged on the left side of FIG. The porous concrete material C is the frame 1 of the slope conveyor 10.
As shown in FIG. 2 (a), the spattering hopper 16 supported by 1 is continuously sprinkled from the bottom of the slope 1 into a strip of a predetermined width so that an approximate thickness can be ensured. Will be issued. Further, the cylinder finisher 20 located at the rear of the slope longitudinal direction and following the slope conveyor 10 scatters, compacts and finishes the sprinkled porous concrete material C.

As shown in FIG. 1, the finisher portion 30
Running along the longitudinal direction of the frame 21, that is, along the slope direction, the porous concrete material C sprinkled out causes the preceding screw spreader 31 to move.
It is scraped evenly to a predetermined thickness. Simultaneously with this, the compaction cylinders 35 at the adjacent positions roll compactively on the concrete surface that has been smoothed to a prescribed thickness in the previous step, so that the unit porous concrete layer C having a prescribed porosity is obtained.
₁ is built. Further, by the extension operation of the lifting cylinder (not shown) incorporated in the traveling legs 12 and 22 of the slope conveyor 10 and the cylinder finisher 20, the unit porous concrete layer thickness assumed between the frames 11 and 21 and the concrete surface is obtained. Can be expanded together. In this way, the slope conveyor 10 and the cylinder finisher 20 shown in FIG. 1 perform a placing cycle in which the porous concrete material C is sprinkled, scraped, leveled, compacted, and finished at the same time. A unit porous concrete layer C ₂ can be constructed. By repeating this placing cycle, a thick porous concrete layer can be constructed.

As described above, the porous concrete material has extremely low fluidity unlike ordinary concrete, and in the case of placing a thick layer, compaction energy due to vibration or compaction rotation is difficult to be transmitted to the entire layer. Therefore, in the present invention, a mechanism for vertically elevating the frame with respect to the porous concrete placing surface by extending the support legs is used to divide the thick layer placing operation into multiple layers to form a plurality of unit porous concrete layers. It was decided to perform laminated construction. As a result, a predetermined performance can be secured even in the case of thick-layer porous concrete.

FIG. 5 (a) shows a cross-sectional shape of a porous concrete layer by multi-layer (two-layer) pouring by the slope concrete pouring device of the present invention. As shown in the figure, in order to make a structure of a porous concrete layer having a predetermined thickness (for example, 20 cm), unit porous concrete layers C ₁ and C ₂ having a layer thickness of 10 cm may be laminated in two layers. Further, in the movement of the compaction cylinder 35 along the direction of the slope, the running guide rail (not shown) provided on the frame 21 of the cylinder finisher 20 is formed into a smooth uneven curved line shape so that the upper unit porous layer is formed. The casting surface of the concrete layer C ₂ can be formed into a continuous smooth uneven curved surface shape as shown in FIG.

[0021]

[Examples] In order to confirm the effects of the multilayer concrete pouring method of the present invention, the core strength and the porosity were measured for each example in which the layer thickness and the compaction method were changed. [Mixture of Porous Concrete Material] Table 1 shows a comparative example,
The compounding of the porous concrete material adopted in the examples is shown. Blast furnace cement type B was used as the cement used.
The target compressive strength is 10 N / mm, which is required for river bank protection.
² As the rolling compaction method, the construction thickness was set to 10, 15, 20, 30 cm in the multilayer placing method of the present application, and the porosity and core compressive strength after construction were measured. In addition, as a comparative example, a construction thickness of 10 by a rolling method using a backhoe,
The performance was measured for 20 cm.

[Table 1]

[Test Results] As shown in Table 2, in the comparison in the construction thickness of 10 cm (Example 1 and Comparative Example 2),
In the conventional method, the compaction effect was low, the porosity was large, and the compressive strength was less than 10 N / mm ² . On the other hand, in Example 1, both the compressive strength and the porosity satisfied the specified values. As is clear from Table-2, when the construction thickness increases, the strength tends to decrease in the further construction and the porosity tends to increase, and this result also clearly shows the necessity of multi-layer construction. As can be seen from the construction thickness of 20 cm (Example 3), it was possible to pour up to 20 cm as a unit porous concrete layer.

[Table 2]

[Example of Construction] An example of construction of a porous concrete layer having a layer thickness of 20 cm on the slope 1 having a predetermined slope will be described below with reference to FIGS. First, a porous concrete material is manufactured in a stationary or mobile concrete plant, and it is brought into the site by a concrete mixer truck or a dump truck. Porous concrete material C is loaded into a hopper suspended by a crane or the like using a take-over machine installed on site, and the hopper is transferred to a loading hopper 15 of a slope conveyor 10 installed on a slope and the material is transported in the slope direction. Possible slope conveyor 10
Then, the spouting hopper 16 is used to continuously spout out the porous concrete material C on the slope 1 with a predetermined width and thickness (FIG. 7). At this time, the quality control test shown in Table 3 is performed.

[Table 3]

Next, the screw spreader 31 of the finisher portion 30 provided on the cylinder finisher 20 following the slope conveyor 10 has a thickness of about 10 for a predetermined unit porous concrete layer thickness (for example, 10 cm).
% The expected average thickness (eg about 11c)
Scratch and level so that it becomes m). The first unit porous concrete layer C ₁ is finished by passing it through a compaction cylinder 35 having vibration and roller compaction functions along the slope direction of the leveling surface of the concrete (FIGS. 8 to 9). . Further, the slope conveyor 10 is moved onto the finished unit porous concrete layer C ₁ of the first layer, and the porous concrete material C is sprinkled out in the same process, and the traveling legs 12 are formed so that the layer thickness after compaction is 20 cm. , 22 are extended to raise the frames 11, 21 by a predetermined amount. The second unit porous concrete layer C ₂ is constructed by passing the slope conveyor 10 and the cylinder finisher 20 on the concrete surface C ₁ along the frames 11 and 21 in this state (FIGS. 10 to 11).
Even when the thickness of the designed porous concrete layer is more than that, by repeating the same operation, the porous concrete layer having a predetermined designed thickness can be finished.

[0028]

As described above, by pouring the porous concrete material by vibration and roller rolling so as to have a predetermined unit thickness, and further by pouring the unit porous concrete layers in multiple layers, Stable porosity and strength can be secured over the entire layer, the quality as porous concrete is greatly improved, the workability is sufficiently increased, and the construction cost can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a plan layout and construction state explanatory view showing an embodiment of a method for constructing a porous concrete slope according to the present invention.

FIG. 2 is a device side view showing the configuration of the slope driving device shown in FIG.

FIG. 3 is a plan view showing a schematic configuration of a finisher portion of a cylinder finisher.

FIG. 4 is a state explanatory view showing a leveling and finishing state by a screw spreader and a rolling cylinder.

FIG. 5 is a schematic cross-sectional view showing a construction cross-section example of a porous concrete layer.

FIG. 6 is a construction flow chart showing an example of construction procedure of a porous concrete layer by the construction method of a porous concrete slope of the present invention.

FIG. 7 is an explanatory view showing a state in which the porous concrete material is spilled out.

FIG. 8 is a state explanatory view showing a finished state of a unit porous concrete layer (lower layer).

FIG. 9 is an explanatory view showing a state where finishing of a unit porous concrete layer (lower layer) is completed.

FIG. 10 is a state explanatory view showing a finished state of a unit porous concrete layer (upper layer).

FIG. 11 is an explanatory view showing a state where finishing of the unit porous concrete layer (upper layer) is completed.

[Explanation of symbols]

1 Slope 2 Rail 10 Slope Conveyor 11, 21 Frame 12, 22 Support Leg 14 Belt Conveyor 15 Loading Hopper 16 Scattering Hopper 20 Cylinder Finisher 30 Finisher Part 31 Screw Spreader 35 Rolling Cylinder C Porous Concrete Material C _i Unit Porous Concrete Layer

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Claims (3)

[Claims] 1. A concrete material is continuously sprinkled on a slope from a material spouting means which is installed along the slope direction and is capable of running in the longitudinal direction of the slope, and is followed by the material spouting means, and in the slope direction. The concrete material sprinkled on the slope is continuously vibrated in the slope direction by the slope finishing means that moves along the slope to roll the roller to form a unit porous concrete layer having a predetermined porosity, and the unit porous concrete layers are laminated. A method for constructing a porous concrete slope, which comprises constructing and constructing a porous concrete slope having a predetermined layer thickness. 2. The slope finishing means includes a screw spreader and a compacting cylinder, and the screw spreader takes the concrete material on the slope into consideration of a predetermined excess with respect to the layer thickness of the unit porous concrete layer. The slope of the porous concrete according to claim 1, wherein the unit porous concrete layer having a predetermined layer thickness is formed by the vibration applied by the rolling cylinder and the roller rolling action after being evenly scraped to a thickness. How to build. 3. The method for constructing a slope of porous concrete according to claim 1, wherein the unit porous concrete layer has a layer thickness of 8 to 20 cm.