JP2005088221A - Porous concrete body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a porous concrete body constituted so as to realize a structure suitable for growing algae at a low cost using a waste material such as slag or the like and capable of accelerating the adhesion growth of algae to restore a submarine forest. <P>SOLUTION: Blast furnace slow cooling slag is used as coarse aggregate becoming the principal part of concrete or copper slag is used as regenerated aggregate and fine aggregate to form the porous concrete body in a porous state with a predetermined void ratio. Bamboo materials having through-holes formed by processing the nodal parts of a bamboo are arranged so as to be embedded in concrete in a piercing state to provide a large number of voids and through-holes in a state arranged in the sea. Cost reduction is realized using slag being a waste material as aggregate and metal components essential to organisms are dissolved in seawater to accelerate the addition and growth of algae on the surface of the porous concrete body. Further, the inhabitation of small fishes and shellfishes is assisted by the through-holes in the bamboo material, and algae and fishes and shellfishers living in an ecosystem in a mutually related state are fixed at the same time not only to establish a state nearer to nature but also to restore the submarine forest. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a porous concrete body that is installed in the sea in order to construct a seaweed reef that restores a seaweed bed, and in particular, a porous concrete body that can easily establish seaweed at a low cost and that is suitable for a seaweed bed restoration. About.

  In recent years, a phenomenon of seaweed decay called “sake burning” has occurred on the coasts of Japan. Causes of this `` burning '' are sea level fluctuations such as water temperature and nutrients, temporary environmental changes such as typhoons, feeding by herbivores, inhibition of other seaweed formation by coral algae, seawater pollution, etc. It is thought that various elements act in a complex manner.

For this reason, conventionally, attempts have been made to restore algae beds by installing algae reefs such as concrete blocks in which seaweed has been established in the sea. Under such circumstances, the porous concrete body is excellent as a material constituting algae reefs and fish reefs because it has a porous structure suitable for the inhabiting of small marine organisms, and its shape can be freely processed in the same way as general concrete. It has characteristics and has been conventionally used for the purpose of restoring seaweed beds. As such a porous concrete body for seaweed restoration, an example in which a material containing a seaweed nutrient such as a nitrogen compound, phosphoric acid or iron is incorporated in a porous material is described in JP-A-5-308771. In addition, JP 2002-315468 A discloses an example in which a steel fiber for enhancing strength and elution of iron ions and a fossil shell for elution of calcium ions are mixed in porous concrete.
Japanese Patent Laid-Open No. 5-308871 JP 2002-315468 A

  The conventional porous concrete body is configured as described above, and it is necessary to prepare all the materials of the porous concrete body by collecting or refining them. Also, the production of the concrete body is complicated and time-consuming. Since the process was included, there existed a subject that cost became high.

  The present invention has been made to solve the above-mentioned problems, and by using a waste material such as slag as a material, a low-cost structure suitable for seaweed growth is realized, and seaweed adhesion growth is promoted to restore seaweed beds. It aims at providing the porous concrete body which can be aimed at.

The porous concrete body according to the present invention is a porous concrete body formed into a predetermined three-dimensional shape using at least cement and water, coarse aggregate, and fine aggregate. A predetermined amount of 25 mm blast furnace cooling slag or recycled aggregate having a particle size of 5 to 20 mm is used, and a predetermined amount of copper slag having a particle size of 2.5 mm or less is used as the fine aggregate, so that the porosity is 10 to 20%. At the same time, the compressive strength is 18 N / mm ² or more and the unit volume mass is 2.3 t / m ³ or more. It is arranged and embedded as it is.

  As described above, in the present invention, the blast furnace decooled slag or recycled aggregate is used as the coarse aggregate which is the main part of the concrete, and the copper slag is used as the fine aggregate, respectively. Bamboo material having a through-hole processed into a knot is embedded and arranged in a penetrating state, and by providing a large number of voids suitable for living organisms and a through-hole surrounded by the bamboo material in an underwater state, In addition to being able to reduce costs by using slag, which is a waste material, lumber also dissolves essential metal components for living organisms into seawater, resulting in a state that helps the growth of seaweed, and seaweed on the surface The growth of seaweed can be promoted together with the attachment of the seawater to be more tough due to the porous nature, and the holes in the bamboo become a place to hide small seafood, helping inhabit and interacting with each other in the ecosystem Seaweed Through the by simultaneously fixed, it is possible to more algae reefs and reef naturally close state, suitable for recovery of the seaweed. In addition, the use of scrap wood that has been cut from the forest for the bamboo that surrounds the through-holes does not increase costs, and bamboo gradually decays and decomposes in the sea to become a nutrient source for seaweed and microorganisms. It is possible to assist, and more seaweed can adhere to the surface and grow.

  Moreover, the porous concrete body according to the present invention is filled with a plurality of layers of uncured concrete kneaded with each raw material, if necessary, and the granular fertilizer is a plurality of times of the uncured concrete. A predetermined amount is sprayed and injected between each layer obtained by charging and tamping.

  In this way, in the present invention, the concrete layer that has been tamped before between the inputs so that the granular fertilizer is positioned between each layer produced by tamping each time the uncured concrete is thrown into the formwork multiple times. Appropriate granular fertilizer that prevents the cement from agglomerating when the contact area with cement increases due to the organic content contained by dispersing granular fertilizer on top and mixing it in uncured concrete without dispersing it With a simple arrangement, the contact with the cement can be kept to the minimum necessary, and the concrete body can be hardened assuredly, thus ensuring strength in the sea. Moreover, since nutrients from granular fertilizer and shell powder are slowly dissolved from the inside of the concrete body in seawater to help the growth of seaweed, the adhesion and growth of seaweed on the surface can be further ensured.

Hereinafter, the porous concrete body which concerns on one embodiment of this invention is demonstrated based on FIG. FIG. 1 is a schematic configuration diagram of a porous concrete body according to the present embodiment.
As shown in FIG. 1, the porous concrete body 1 according to the present embodiment is formed into a predetermined three-dimensional shape by a mold using cement and water, coarse aggregate, fine aggregate, and the like as raw materials. By compaction, the porosity is finally 10 to 20%, the compression strength is 18 N / mm ² or more, and the unit volume mass is 2.3 t / m ³ or more. Desirably, the porosity is about 15% and the compressive strength is about 21 N / mm ² . And in this porous concrete body 1, before hardening, the bamboo material 2 which penetrated the node part is arrange | positioned in the penetration state in several places, and is embedded as it is.

  Among the above materials, a blast furnace decooling slag having a particle size of 5 to 25 mm or a regenerated aggregate having a particle size of 5 to 20 mm is used as the coarse aggregate, and a particle size of 2.5 mm or less is used as the fine aggregate. A predetermined amount of copper slag is used. By using high-density copper slag for the fine aggregate, the weight per unit volume can be increased and it can be made difficult to be washed away by the ocean current.

  In addition, in the porous concrete body 1, granular fertilizer is mixed with a cement mass ratio of 2.5%, and if necessary, shell powder is mixed with a cement mass ratio of 1.0%. These granular fertilizer and shell powder are not kneaded integrally with each material, but are separately added to uncured concrete kneaded with other materials in a later step.

  Next, the manufacturing process of the porous concrete body based on the said structure is demonstrated. First, as a concrete mixing step, cement and fine aggregate are put into a mixer and mixed for about 30 seconds, and then water and an admixture are added and mixed for about 180 seconds. At this time, the water is kneaded while increasing / decreasing the water so that the target flow value is obtained. Finally, when coarse aggregate is added and kneaded for about 60 seconds, it can be used as ready-mixed concrete and is discharged from the mixer.

  The obtained ready-mixed concrete is put into a mold for forming an algal reef in an uncured state and molded. In the formwork, a plurality of bamboo materials 2 which have been pulled out in advance and placed in a penetrating state are arranged, and in a shape in which the concrete is integrally cured, a state in which the bamboo material 2 penetrates the concrete body together with the central through hole 3 is obtained. .

  The concrete is put into a formwork with two or more layers, and a predetermined amount of concrete is charged and tamped to form one layer a plurality of times. In order to increase the weight in advance, a mortar layer 4 may be separately laid on the lower portion to form a mortar layer 4, and then the concrete may be charged and tamped. After each layer is sufficiently tamped, it is compacted by applying a formwork vibrator from the upper surface until it is firmly compacted.

  Each time a layer is obtained by putting and solidifying the uncured concrete into a mold, a predetermined amount of granular fertilizer and shell powder are sprayed and placed between the concrete layers. By mixing granular fertilizer in uncured concrete without dispersing it, the contact area between granular fertilizer and cement is minimized, and when the contact area between granular fertilizer and cement increases, the granular fertilizer becomes organic. The property of preventing the cement from hardening is not expressed by the minute, and the strength of the concrete body is ensured by ensuring the integral hardening of the concrete body. The porous concrete body 1 thus created in the mold is demolded after a predetermined time, and after completion of curing for a predetermined period, it is in a completed state.

  The obtained porous concrete body 1 is always installed in a state where it is submerged in the sea where seaweed is reduced due to burning in the sea. When installed in the sea, the porous concrete body 1 provides a large number of voids suitable for living organisms and through holes 3 surrounded by the bamboo material 2, and the nutrients from the granular fertilizer and shell powder are slowly added from the inside to the seawater. It can promote the adhesion and growth of seaweed on the concrete body surface. In addition, the through-holes 3 in the bamboo material 2 serve as a place where small fish and shellfish are hidden to help the habitat. On the other hand, the bamboo material 2 gradually decays and decomposes in the sea and becomes a nutrient source for seaweed and microorganisms. It is possible to assist and to allow more seaweed to adhere to the surface and grow. In addition, the porous concrete body 1 is installed in a place where seaweed is likely to adhere and grow. After the seaweed is sufficiently attached to the surface, the porous concrete body 1 is carried to another place where seaweed is reduced due to another burning of seaweed. You can also.

  Thus, in the porous concrete body according to the present embodiment, blast furnace decooled slag or recycled aggregate is used as the coarse aggregate that is the main part of the concrete, and copper slag is used as the fine aggregate. The bamboo material 2 having a through-hole 3 formed in a state and having a through hole 3 is embedded and disposed in a state of being surrounded by a large number of voids and bamboo material suitable for living organisms in the state of being placed in the sea. In addition to realizing cost reduction by using waste slag and the like as aggregate, the indispensable metal component for living organisms also melts into seawater, resulting in seaweed A state that helps the growth is obtained, the adhesion and growth of seaweed to the surface can be promoted, and the holes in the bamboo become a place where small fish and shellfish are hidden, helping the habitat, and living in relation to each other in the ecosystem Seaweed and seafood By wearing it can be more algae reefs and reef naturally close state, suitable for recovery of the seaweed. In addition, granular fertilizer and shell powder are mixed in, and nutrients from the granular fertilizer and shell powder are slowly dissolved from the inside of the concrete body in seawater to help the growth of seaweed. More reliable.

  In the porous concrete body according to the above-described embodiment, granular fertilizer is mixed into the concrete, and this is eluted in the sea so as to assist the adhesion and growth of seaweed. The blast furnace chilled slag can be pre-impregnated with water-soluble fertilizer and then kneaded with cement as a coarse aggregate, and then integrally hardened. After installation in the sea, from the hole on the surface of the chilled slag in contact with seawater The fertilizer will dissolve in the seawater, helping the adhesion and growth of seaweed.

  Moreover, in the porous concrete body according to the embodiment, the surface is configured to remain in a state where the color of cement, coarse aggregate, and fine aggregate appears, but in addition, when mixing concrete It can also be configured to mix with liquid paint or colored powder, making the obtained concrete body closer to the natural sea floor color, making it easier for marine organisms other than seaweed, especially seafood to settle on the concrete body. Therefore, the role as a fish reef can be fully fulfilled. Furthermore, since the concrete body is colored as a whole, even if the surface is eroded in seawater, the color is maintained as it is, and the effect that does not give a sense of incongruity to living things can be maintained.

  A plurality of types of porous concrete bodies according to the present invention will be manufactured under different mixing conditions, and the evaluation results will be described in comparison with the adhesion state of seaweeds installed in the sea together with comparative examples in which the types of coarse aggregates were changed.

  As Example 1 of the porous concrete body according to the present invention, a porous concrete body formed by using blast furnace decooling slag as coarse aggregate and mixing with granular fertilizer serving as a nutrient for promoting adhesion growth of seaweed is obtained. It was. This porous concrete body is a substantially trapezoidal block body having a bottom surface of 300 × 400 mm and a height of 300 mm.

  Moreover, as Example 2 of the porous concrete body, a porous concrete body obtained by replacing the coarse aggregate of Example 1 with a recycled aggregate was obtained. This porous concrete body also has the same shape and size as the first embodiment.

  Moreover, as Example 3 of the porous concrete body, in addition to the preparation of Example 2, a porous concrete body formed by mixing shell powder as a nutrient and black powder as a paint was obtained. This porous concrete body also has the same shape and size as the first embodiment.

  Moreover, as Example 4 of the porous concrete body, a porous concrete body obtained by replacing the paint of Example 3 with a green acrylic resin liquid was obtained. This porous concrete body also has the same shape and size as the first embodiment.

  Furthermore, as Example 5 of the porous concrete body, a porous concrete body formed by replacing the paint of Example 3 with a red acrylic resin liquid was obtained. This porous concrete body also has the same shape and size as the first embodiment.

  In addition, as a comparative example 1, the coarse aggregate of Example 1 is replaced with a general crushed stone (crushed stone No. 5 having a particle size of 13 to 20 mm) to obtain a porous concrete body formed without mixing granular fertilizer. It was. This porous concrete body also has the same shape and size as the first embodiment.

  Furthermore, as Comparative Example 2, a porous concrete body made of ordinary concrete using general coarse aggregate and fine aggregate was obtained. This porous concrete body also has the same shape and size as the porous concrete bodies of the above-described Examples and Comparative Example 1.

The materials used for forming the porous concrete bodies in the respective Examples and Comparative Example 1 will be described. Cement is Blast Furnace Cement Type B with a density of 3.04 g / cm ³ , Coarse Aggregate is Crushed Stone No. 5 (in the case of Comparative Example 1), Blast Furnace Cooling Slag with Particle Size of 5-25 mm, or Particle Size of 8-20 mm Recycled aggregate. As the fine aggregate, copper slag having a particle size of 2.5 mm or less was used. In addition, a necessary amount of an admixture such as a polycarboxylic acid-based water reducing agent is also used. In the blending, the water cement ratio is 25% and the target porosity is 15%. The granular fertilizer mixing rate is 2.5% of the cement mass ratio. In addition, the shell powder mixing ratio is 1.0% to cement mass ratio, the black powder paint mixing ratio is 5% to cement weight ratio, and the green and red liquid paint mixing ratio is 5% to water volume ratio to replace water. doing.

  For mixing the concrete, a mixer is used. First, cement and fine aggregate are added and mixed for 30 seconds, and then water and an admixture are added and mixed for 180 seconds. At this time, it adjusts by increasing / decreasing water so that it may become the target flow value (190 mm), and finally, coarse aggregate is thrown in, it mixes for 60 seconds, and it discharges | emits from a mixer.

  The underwater immersion test specimen is placed in three layers after mortar is laid on the lower 50 mm in a formwork in which a plurality of bamboo materials having a diameter of about 40 mm with nodes pierced are arranged. For compaction, after each layer is sufficiently solidified with a stick, a mold vibrator is applied from the upper surface until it is firmly compacted. Each time it is put into each layer and tamped, a predetermined amount of granular fertilizer is sprayed and placed between the layers. Specimens produced by integrating the bamboo material were demolded after 24 hours and subjected to outdoor poultice curing.

  Each example and comparative example of the porous concrete body obtained as described above were submerged in the sea after sufficient curing. And about 3 months after immersion in the sea, the adhesion area of the seaweed to the porous concrete bodies of each Example and Comparative Example was measured. A graph of the measurement results is shown in FIG.

  As for the amount of seaweed attached, from Fig. 2, the porous concrete body using uncooled slag or recycled aggregate as coarse aggregate is more seaweed than those using coarse aggregate as crushed stone or ordinary concrete. It can be seen that more is attached.

  Thus, it can be confirmed that the porous concrete body according to the present invention can promote adhesion and growth of seaweed by using blast furnace decooled slag and recycled aggregate in coarse aggregate and mixing granular fertilizer. It was.

It is a schematic block diagram of the porous concrete body which concerns on one embodiment of this invention. It is seaweed adhesion area measurement result explanatory drawing of the Example and comparative example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Porous concrete body 2 Bamboo material 3 Through-hole 4 Mortar layer

Claims (2)

In a porous concrete body formed into a predetermined three-dimensional shape using at least cement and water, coarse aggregate, and fine aggregate,
As the coarse aggregate, a predetermined amount of blast furnace cooling slag having a particle size of 5 to 25 mm or recycled aggregate having a particle size of 5 to 20 mm is used, and a predetermined amount of copper slag having a particle size of 2.5 mm or less is used as the fine aggregate. The porosity is 10 to 20%, the compressive strength is 18 N / mm ² or more, and the unit volume mass is 2.3 t / m ³ or more.
A porous concrete body characterized in that bamboo material, which has been processed to penetrate through a node portion, is disposed in one or a plurality of locations in a penetrating state at least before being hardened, and is embedded as it is. In the porous concrete body according to claim 1,
The uncured concrete mixed with each raw material is put into a plurality of layers, and granular fertilizer is sprayed in a predetermined amount between each layer obtained by multiple times of the uncured concrete filling and tamping. Porous concrete body characterized by being introduced.

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