JP3536035B2 - Method for constructing seaweed beds of seaweed having rhizomes such as eelgrass and self-disintegrating porous concrete block used for the method - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a self-collapsing porous concrete block which is adapted to be collapsed after a suitable number of days has passed after installation, and which is preferably adopted when planting algae or the like under the sea surface. The present invention relates to a seaweed bed formation structure and a seaweed bed formation method using the same.

[0002]

[Background Art] Conventionally, research on techniques for establishing and growing seaweeds has been carried out especially on lambs and slugs that grow in coastal reef areas.
Many things have been done with respect to attached seaweeds such as Honda straw, for example, by putting natural stones and concrete blocks cut out from mountains into the sea and making them exist permanently in the middle. However, as for the planting of seaweeds such as eelgrass having rhizomes, the actual situation has not been proposed yet.

[0003] That is, since eelgrass grows rhizomes on the sandy land in the shallow water near the coast by growing the rhizomes in the sandy land, it is possible to put natural stones or concrete blocks into the sea like attached seaweed. However, effective growth is difficult to achieve, and even if sowing or planting is carried out, even if seedlings or seedlings are not developed, they can be effectively grown by being exposed to scraping by fishing nets, drifting sand, and drainage of sandy land by ocean currents. Cannot be expected.

In order to deal with such a problem,
JP-A-8-242717 and JP-A-9-74939.
Japanese Patent Laid-Open No. 9-191784 and the like propose seaweed bed formation structures such as eelgrass. In all of these, a net-like body stretched and installed on the surface of a sandy ground is made of metal or concrete. The structure is only fixed by a fixed weight consisting of objects, and it can exert a satisfactory effect on problems such as the runoff of sandy land due to ocean currents and the accompanying loss of unengrafted eelgrass. There was never one.

[0005]

The present invention has been made in view of the circumstances as described above, and the problem to be solved by the present invention is that it can be advantageously applied to the formation of seaweed beds such as eelgrass. It is to provide a self-collapsing porous concrete block with a novel structure that is not available in Japan.

Another object of the present invention is to provide a novel seaweed bed construction structure and a new seaweed bed construction method as an invention of the use of such a novel structure of a self-collapsing porous concrete block.

[0007]

SOLUTION AND SPECIFIC STRUCTURE OF THE INVENTION The features of the present invention and the specific structure thereof for solving the above problems will be described below. The features and specific configurations of the present invention described below can be used in any combination as much as possible. In addition, the features and specific configurations of the present invention are as follows.
It is understood that the present invention is not limited to those described below, but is to be understood based on the entire specification and drawings, or based on the inventive idea that can be understood by those skilled in the art from those descriptions. Should be.

First, a feature of the present invention relating to a self-collapsing type porous concrete block is that in the porous concrete in which continuous pores are formed inside by integrally forming aggregates by connecting them with a binder, In at least one of the binders, there is provided a self-collapsing porous concrete block in which an alkali-silica-reactive mineral is used in a blending amount preferable for causing expansion and collapse by alkali stimulation.

That is, since concrete blocks have been very excellent in strength, durability, flexibility in molding, and cost efficiency, concrete blocks have been used in the fields of civil engineering and construction including strength members of various structures. Although widely adopted for the first time, concrete blocks have been endeavoring to improve their durability exclusively over a long history. For example, even in the JIS standard, the concrete amount is limited by limiting the alkali amount of cement or aggregate. It is also clear from the fact that it is specified that the alkali-aggregate reaction, which is the main cause of the deterioration of durability of concrete, is suppressed as much as possible by limiting the material.

However, in response to the extremely difficult technical requirements for creating seaweed beds such as eelgrass as described above, the present inventors have found that the conventional "concrete block is as excellent as possible in strength and durability. By shifting the idea away from the idea of `` desirable '', we arrived at a new innovative technology this time, and as a result, as described above, a self-collapsing porous concrete block with a novel structure. The invention according to can be completed.

Here, the self-collapsing porous concrete block according to the present invention having the above-mentioned structure is, so to speak, "a concrete block intended to collapse" or "a concrete block intended to be actively collapsed". However, in particular, under the change of the idea of 180 degrees that the alkali-aggregate reaction, which was conventionally considered only as a drawback in the technical field of concrete, is positively used as an advantage, By utilizing alkali silica reactive minerals, which have been considered taboo exclusively in the field, and combining them with porous concrete with a continuous porous structure, self-destruction with completely new structure and characteristics It was possible to realize a type of porous concrete.

In the self-collapsing porous concrete according to the present invention, since it has a porous structure and a continuous porous structure, for example,
By growing and entering a rhizome such as eelgrass into the pores, in addition to being able to advantageously form a substrate for the medium of seaweed having a rhizome, since it is a self-disintegrating type as described above, for example, It gives a seaweed bed consisting of an artificial block structure made of a heavy rigid body only until the rhizome of seaweeds such as eelgrass develops sufficiently, but after a certain period of time, the rhizome develops specially. Without requiring work, it is possible to collapse such a block structure and bring it into a state close to nature to avoid adverse effects on the environment.

Further, in the present invention relating to the self-collapsing type porous concrete block, it is possible to crush or crush waste glass and employ it as the alkali silica reactive mineral, thereby treating waste. The problematic waste glass can be effectively used, and the recycling of waste can be advantageously realized.

Here, the waste glass used in the present invention includes various kinds of glass such as plate glass, lead crystal glass, lighting glass, physics and chemistry glass, fiber glass, etc., in addition to bottle glass, but especially alkali Those having a remarkable silica reaction are effective. In particular, in the current situation where bottle glass is not being recycled, the reality is that bottle glass as waste is crushed at many disposal sites and left as cullet in order to reduce its volume. It is possible to effectively utilize such waste glass in this embodiment.

Further, the alkali-silica-reactive minerals used in the present invention relating to the self-collapsing porous concrete block include, as well as the waste glass as described above, various alkali-silica-reactive minerals known as alkali-reactive aggregates from the past. Minerals can be adopted, and specifically, for example, negative crystallite quartz, chalcedony, opal, volcanic glass, cristobalite, trijmalite, etc. are known. Of these, implicit microcrystalline quartz and chalcedony are often contained in sedimentary rocks, and other minerals are often contained in volcanic rocks, and there are many examples of damage caused by alkali-silica reaction in Japan. Considering that the seeds are andesite and chert, the andesite and chert can be preferably adopted in the present invention. Whether or not the substance is an alkali-silica-reactive mineral can be easily determined by, for example, the chemical method and the mortar bar method defined by the appendix of JIS A 5308 (ready-mixed concrete).

Here, the alkali-silica-reactive minerals that can be employed in the present invention as described above should be classified as to whether or not they have a problematic alkali-silica reactivity depending on the formation or dyke from which they are produced. In the past, if it was determined that the mineral was an alkali-silica-reactive mineral, the separated rocks are treated as waste, and recycling is not actually done. Therefore, the present invention can be expected to have a new technical effect of effectively utilizing such rocks.

The alkali-aggregate reaction in concrete is a chemical reaction in which an aggregate having reactivity with alkali metal supplied from cement or seawater generally forms an alkali silicate gel and expands with water. As a result, it is possible to destroy the binder and cause the concrete block to naturally collapse. And since such an alkali-aggregate reaction has a track record and results in which many studies, experiments, and studies have been carried out as an extremely large problem in concrete, these results are opposite to each other in the present invention. It can be used from a physical perspective. For example, for alkali-reactive aggregates made of alkali-silica-reactive minerals, the degree of deterioration has already been classified based on the amount of swelling, etc., depending on the type of minerals and their content, and there are many data. Therefore, by appropriately using these known various data,
It is possible to predict or control the time when the self-collapsing porous concrete block having the structure according to the present invention naturally collapses to some extent. When the waste glass is used as the alkali-silica-reactive mineral, it is preferable for the aggregate or the binder in both cases of using it as an aggregate and as a mixture to the binder. Is 5% by weight or more, more preferably 10% by weight or more, and further preferably 25% by weight, and particularly 50% by weight is used as an aggregate.
It is more desirable to use it in a proportion of not less than wt%.

Further, the particle size of the alkali-silica-reactive mineral also affects the alkali-silica reaction, and the inventors of the present invention have studied and found that it generally produces an effective alkali-silica reaction, although it depends on the material. It is desirable that the particle size of the alkali-reactive aggregate is 0.3 mm or more, and the particle size of 0.3 to 30.0 mm is particularly preferably adopted. The waste glass preferably used as the alkali silica reactive mineral in the present invention generally has a crushed particle size of 3 to 2 depending on the kind of the crusher.
Since it is set to about 0 mm, it can be used as it is, or if necessary, only by removing contaminants such as paper adhering to the surface by washing or the like.

In the present invention, it is possible to employ an alkali-silica-reactive mineral as an aggregate or a binder, but when it is used as an aggregate, continuous pores are advantageous. For the purpose of forming, it is desirable to set the particle size to a coarse aggregate or a fine aggregate. Specifically, in terms of the aggregate particle size conventionally used as an index, it is a single particle size. No. 5 (13-
25 mm), No. 6 (5 to 13 mm) or No. 7 (2.5 to 5)
mm) is preferably adopted. On the other hand, when compounded in a binder such as cement paste, the particle size is preferably 5 mm or less, more preferably 2.5 mm or less from the viewpoint of the productivity of porous concrete. It

Furthermore, in the present invention, the cement employed as the binder is not particularly limited, and various portland cements, blast furnace cements, alumina cements,
Any of fly ash cement, slag cement, silica cement, magnesia cement and the like can be used, but ordinary portland cement and blast furnace cement are preferably used. Here, in the conventional concrete, a highly alkaline cement, which has not been adopted because it easily causes an alkali-aggregate reaction, for example, a cement having a total alkali content of more than 0.75% is also advantageously used. obtain. In addition to cement, an admixture such as silica fume or an admixture such as an active sustaining polymer may be appropriately mixed with the bonding material.

The alkali required for causing the alkali-aggregate reaction is not only the alkali metal ion contained in the concrete material but also the alkali contained in seawater, the deicing agent, etc. easily from the outside. In particular, low-alkali concrete can be used in the present invention because it can be supplied very easily and abundantly depending on the installation environment of the concrete block.

In particular, since the present invention adopts the porous concrete structure, it is easily and uniformly affected by the external environment throughout the inside of the block. For example, when it is installed in the sea, Since the seawater is guided through the continuous pores formed in the concrete block and brought into a water-passing state, there is a feature that the alkali-aggregate reaction proceeds uniformly.

Further, in the present invention, the continuous pores are
It is desirable to form with a porosity of 15% or more, so that, for example, when forming a seaweed bed or the like by the self-collapsing porous concrete block according to the present invention, sand or the like is filled into continuous pores to advantageously form a medium. In addition to being able to form, seaweeds and the like can easily be allowed to penetrate into the open pores of the rhizome, and the rooting can be made good. Incidentally, if the porosity is too large, in addition to the possibility of causing a problem in strength, for example, the retention in the continuous pores of the medium when forming a seaweed bed or the like may decrease, It is desirable to suppress the porosity to 30% or less.

As a method for achieving the desired porosity, for example, it is possible to adjust by compaction at the time of filling the aggregate into the mold, but in the present invention,
A control method by blending is preferably adopted. The method of controlling the porosity by blending is to obtain the actual rate (filling ratio) of the aggregate in advance, remove the required void volume from other volumes, and fill the remaining volume with cement paste. Say the method. According to the porosity control method based on such a composition, the porosity can be set and controlled with higher accuracy as compared with the control by compaction.

The self-collapsing porous concrete block according to the present invention can be planted by filling the continuous pores with a medium such as soil or sand as described above, Thereby, for example, the rhizome can be allowed to enter the continuous pores to form a seaweed bed or the like. At that time, it is also possible to provide a pot-shaped recess that opens on the surface of the block and to fill the pot-shaped recess with a medium such as soil or sand for planting.

Furthermore, the present invention provides a seaweed bed construction in which a base for planting algae is formed in water by installing the self-collapsing porous concrete block having the structure according to the present invention as described above in water. The structure is also a feature. In such a seaweed formation structure, since the porous concrete structure is adopted, it is possible to realize a seaweed bed where algae can firmly attach and vegetate by allowing the rhizome to enter the inside of the block. By positively utilizing the alkali-aggregate reaction, the concrete block will spontaneously self-collapse after the rhizome has developed sufficiently and sufficient adhesion to the ground can be exerted. The adverse effects on nature and the fishing ground environment can be reduced or avoided as much as possible.

In addition, the present invention fills continuous pores in the self-collapsing porous concrete block having the structure according to the present invention with a medium, and sows or plants algae in the medium, The seaweed bed creating method of immersing such a self-collapsing porous concrete block in seawater and installing it on the seabed is also a feature. According to such a method of the present invention, as described above, the seaweed beds of seaweed having rhizomes can be advantageously formed while reducing or avoiding the influence on the surrounding environment. In addition,
Seeding and planting of algae to the medium, mixing seeds or the like in the preparation of the binder, or pre-mixing seeds or the like in the medium to fill the continuous pores, the seeds to the medium surface provided in the concrete block Various methods such as planting and vegetation can be adopted.

[0028]

EXAMPLES Hereinafter, examples of the present invention will be described in order to clarify the present invention more specifically, but the present invention is to be construed in a limited manner by the description of the following examples. Not. In particular, the application of the self-collapsing concrete block having the structure according to the present invention is not limited in any way, and is applicable to the formation of seaweed beds of various seaweeds other than eelgrass described in the following examples. Besides, it goes without saying that it can be laid on the slopes of river banks to protect vegetation in the early stages of growth, or can be used for planting trees in parks, etc. It can also be applied to the field of civil engineering, such as efficiently performing embankment such as preloading.

First, a waste glass cullet consisting of another type of bottle glass recovered from a waste disposal site was immersed in a sodium hydroxide solution to remove impurities adhering to the surface. The obtained waste glass cullet as an alkali silica reactive mineral was dried and then classified using a sieve having a mesh of 5 mm into fine cullet of 5 mm or less and coarse cullet of larger than 5 mm. The fine cullet thus obtained is treated with ordinary Portland cement having an alkali content of 0.75% or less and water.
A binder having an alkali-silica-reactive mineral mixed therein was obtained by mixing the cement paste prepared by adjusting the cement ratio to 21 to 23% and kneading the paste with the paste.

In this cement paste, water / water is used as compared with the case of obtaining general concrete.
Considering that the cement ratio is small, 1 to 5% of the high-performance AE water reducing agent was added. In addition, the kneading time of the pre-mixed cement paste is preferably set longer than the general concrete kneading time in consideration of the fact that waste glass cullet is mixed and the water / cement ratio is small,
In this example, which employs a forced twin-screw type kneader, control was performed for 180 to 450 seconds while observing the state. The kneading time varies depending on the type of the kneading machine, and as a result of more experiments, the kneading time of 180 to 450 seconds was suitable for the forced twin-screw type, but it was 270 to 4 for the omni type.
About 50 seconds was suitable.

The coarse cullet as an aggregate and the rock crushing material as an alkali-silica reactive aggregate were added to the slurry-like binder thus obtained and further kneaded. The kneading time after adding the aggregate does not depend on the type of the kneading machine, and a kneading time of about 90 seconds is sufficient, whereby a homogeneous binder can be obtained. Further, in this embodiment, the weight ratio of the coarse cullet in the aggregate is set to 3
It was set to 0 to 60%.

Then, the raw material is put into a molding frame and compacted by vibration and pressure to obtain 20 cm × 20 cm × 10 cm.
The rectangular parallelepiped was molded. In addition, in such molding, the porosity is adjusted by taking a compounding method of filling the remaining volume excluding the filling ratio of the preset aggregate and the volume of the void from the in-mold volume with cement paste. Then, the porosity was set to three types of 15%, 20% and 25% to obtain a plurality of individuals. Then, a curing period was set to obtain a self-collapsing porous concrete block as an example.

When the obtained self-collapsing porous concrete block of this example was observed, as shown in FIG. 1, coarse glass 10 as aggregate and rock crushed material 12 as paste mixture were obtained. It was confirmed that the structure has a continuous porous structure void 18 integrally bonded and fixed by a binder 16 containing the fine glass 14.

A uniaxial compression test was carried out on each of the self-collapsing porous concrete block structures, and it was confirmed that the strength was within the range of 10 to ²⁰ N / mm ² , and that it had a practical strength.

Subsequently, sea sand (particle size: 0.
3 to 2.0 mm), and as shown in FIG.
A medium was constructed by filling the voids 18 in the self-collapsing porous concrete block of the example with this embedding material 20. Then, a plurality of self-collapsing porous concrete blocks obtained in this way, using experimental equipment immersed in a tank of which seawater is constantly pumped and circulated, by sowing eelgrass against such a medium, cultivation A breeding experiment was conducted.

In such an experiment, the seeding time of eelgrass was
Based on December. Although the temperature of the cultivation water was not basically controlled, it was heated to 9 ° C only during the severe winter. Cultivation day length was not controlled and carbon dioxide was not intentionally added.

As a result of the growth experiment under such conditions, germination of eelgrass could be observed in the self-collapsing concrete block structures of any of the examples within 1 to 2 weeks after sowing. After that, it was confirmed that the eelgrass grew smoothly. In addition, due to the test schedule, the concrete block collapse rate has not been observed, but from the past data, all of the self-collapsing concrete blocks used in this example naturally collapsed after a predetermined time. It is clear that you will.

[0038]

As is apparent from the above description, the self-collapsing concrete block having a structure according to the present invention is a novel structure based on a technical idea that has never been found in the past, and adopts such a structure. Thus, for example, the formation of seaweed beds of seaweed, which grows mainly on rhizomes such as eelgrass, can be advantageously realized.

Further, such a self-collapsing concrete block naturally collapses after a suitable period of time, and in particular, it is possible to use waste glass as an aggregate, whereby the existing glass is used. However, it is also possible to advantageously use comprehensive environmental conservation technologies that restore the natural environment by effectively utilizing waste glass as waste, for which no effective utilization method has been found, as a recycling material. is there.

[Brief description of drawings]

FIG. 1 is a sectional explanatory view showing a self-collapsing concrete block as one embodiment of the present invention.

2 is a cross-sectional explanatory view showing a seaweed bed formed using the self-collapsing concrete block shown in FIG.

[Explanation of symbols]

10 coarse glass 14 thin glass 16 Binder 18 void 20 Embedded materials

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akihiro Maekawa 5-545 Takachaya, Tsu City, Mie Prefecture Mie Prefectural Science and Technology Promotion Center, National Institute of Advanced Industrial Science and Technology (72) Inventor Tsujigado Shun Suzuka City, Mie Prefecture Shirako 1-6277-4 Mie Prefectural Science and Technology Promotion Center Fisheries Technology Center-Isewan Branch (72) Inventor Hiroshi Yamada 1-6277-4 Shirako Suzuka-shi, Mie Fisheries Technology Center Mie Prefectural Science and Technology Center-Isewan Branch Field (56) Reference JP-A-11-137117 (JP, A) JP-A-10-43 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) A01G 33/00

Claims (5)

(57) [Claims] 1. Waste glass is crushed or crushed into five layers
Using a self-disintegrating type porous concrete block in which continuous pores are formed by bonding aggregate containing at least% by volume with cement, a medium is formed by filling continuous pores of the porous concrete with soil or sand. , By sowing or planting seaweed having rhizomes such as eelgrass against the medium, by immersing the porous concrete block in seawater and installing it in a sandy mud on the seabed, such seaweed grows After the development of the rhizome, the sea eelgrass is characterized in that the aggregate made of the waste glass is caused to undergo self-destruction due to an alkaline aggregate reaction, and the porous concrete block is totally collapsed to a seabed state close to nature. Method for creating seaweed beds of seaweeds having rhizomes such as. 2. As the cement for binding the aggregate,
The method for constructing a seaweed bed of seaweed having rhizomes such as eelgrass according to claim 1, wherein a mixture of waste glass having a particle diameter of 5 mm or less is adopted. 3. A porous concrete block used for creating a seaweed bed of seaweed having rhizomes such as eelgrass, which is 5% by weight of crushed or crushed waste glass.
For vegetation of seaweeds having rhizomes such as eelgrass by filling the aggregate containing the above with cement and forming continuous pores in the inside with a porosity of 15 to 30% to fill the continuous pores with soil and sand Alkaline bone of the aggregate consisting of the waste glass after the underground diameter of the seaweed vegetated by immersing it in seawater and installing it in the sandy mud of the sea bottom A self-collapsing porous concrete block for creating a seaweed bed of seaweed having rhizomes such as eelgrass, which is characterized by being able to provide a seafloor state close to nature by self-collapsing due to wood reaction. 4. The cement that bonds the aggregate,
The self-collapsing porous concrete block according to claim 3, wherein a mixture of waste glass having a particle size of 5 mm or less is adopted. 5. those crushed or grinding the waste glass fivefold
Using a self-disintegrating type porous concrete block in which continuous pores are formed by bonding aggregate containing at least% by volume with cement, a medium is formed by filling continuous pores of the porous concrete with soil or sand. , By sowing or planting seaweed having rhizomes such as eelgrass against the medium, by immersing the porous concrete block in seawater and installing it in a sandy mud on the seabed, such seaweed grows After the development of the rhizome, the seaweed having rhizomes such as eelgrass is characterized in that after the self-destruction of the aggregate composed of the waste glass due to the alkaline-aggregate reaction occurs, it becomes a seabed state close to nature. Structure of seaweed beds of various species.