JP2006249733A - Pavement block for cleaning environment and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pavement block for cleaning an environment and its manufacturing method capable of eliminating and detoxifying a pollutant such as nitrogen oxides and granular matter. <P>SOLUTION: This pavement block for cleaning the environment is composed of cement paste mixed cement with water, a powdery carbonized material of crushing a carbonaceous substance provided by carbonizing a woody biomass 3, a coarse aggregate, a fine aggregate and an admixture material. Concrete mixed with the cement paste, the coarse aggregate, the fine aggregate and the admixture material is filled in a form. A mortar mixture mixed with the cement paste, the carbonized material, the fine aggregate and the admixture material is filled in the form so as to be laminated on a surface of the concrete. The pavement block is provided by solidifying, curing and solidifying the filled concrete and the mortar mixture. Charcoal powder eliminates and detoxifies the pollutant. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an environmental purification pavement block that eliminates and detoxifies pollutants such as nitrogen oxides (NOx) and particulate matter (PM) harmful to the human body diffused in the atmosphere, and a method for manufacturing the same.

  Mankind has been given convenience and comfort through the remarkable development of science and technology since the last century, but on the other hand, the destruction of the environment such as global warming and the generation of harmful gases due to the consumption of resource energy has progressed. The era of "

Global warming is based on the expansion of energy consumption at the cost of convenience and comfort, that is, based on a significant increase in greenhouse gases such as carbon dioxide. As long as the raw material is used, the technology for suppressing the amount of carbon dioxide (CO ₂ ) generated has almost reached the limit.

In recent years, the sustainable growth of forest resources and their use as carbides have attracted attention as a means of reducing the amount of CO ₂ generated, and this has become a highly promising era.

In Japan, pollution from exhaust gas from factories and automobiles in cover roads such as metropolitan areas and tunnels, particularly nitrogen oxides (NOx) and particulate matter (PM) harmful to the human body, has become serious.
In order to suppress these effects, purification technology of the exhaust gas generation source and the surrounding environment after diffusion, especially the air environment in cover roads such as tunnels, has been studied, and it is closed using NOx concentration, heat desorption operation, or a ventilator. Techniques such as discharging contaminated air in the space to the outside are used.
These have high energy consumption, and have the problem that both the equipment cost and the operating cost can be huge, and are merely diffusing polluted air to the outside.

On the other hand, in the fiscal year 1996-1997, the Ministry of Education, Culture, Sports, Science and Technology subsidy, “Development of detoxifying conversion material of NOx by combining high-temperature calcined coal of residual wood and transition metal element oxide” etc. In particular, wood carbides carbonized at 600 to 1000 ° C. can convert NOx in the surrounding environment into harmless dinitrogen (N ₂ ) at room temperature, high heat resistance, oxidation resistance, thermal shock resistance, and high heat resistance. Technology development of dimensional stability charcoal preparation method and high-functional composite materials, and carbonized wood is carbonized by self-heating generated from the wood itself, so the amount of carbon dioxide (CO ₂ ) produced in the manufacturing process It has been reported that it has a feature such that it is small and does not generate CO ₂ unless it is burned, and the creation of a harmless conversion composite material of NOx has been proposed.

Conventionally, a composite composition comprising a powdered, granular or flake wood carbonized material and a powdered natural porous inorganic material is integrally molded by heating at a high temperature in a state of filling a mold of a predetermined shape. The purified product thus obtained is disclosed as Patent Document 1.
JP 2003-201189 A

  The 21st century is said to be the "environmental era" because today's socio-economic system has received many conveniences and comforts due to advances in science and technology since the last century. This is because mass consumption and mass disposal economic activities have rapidly increased the environmental load, and have unbalanced the natural environment, which is the basis for human survival, and have caused various environmental problems.

In particular, there are two major environmental problems related to the atmospheric environment: global warming due to the generation of greenhouse gases, and an increase in harmful gases that cause health damage.
In order to solve these problems, a material and a technique capable of eliminating and detoxifying the exhaust diffused gas without using new energy are required.

  In addition, there is a demand for technological development that uses forest resources and local resources of the global environment and contributes to the promotion of local industries while preserving the global environment and revitalizing economic activities.

  Therefore, an object of the present invention has been made in view of the above circumstances, and uses woody biomass such as wood capable of stable supply of raw materials locally, with cement and charcoal powder as main raw materials. The mortar mixture can be used as a molding material for paving blocks, the manufacturing cost is low, and pollutants such as nitrogen oxides and particulate matter that are harmful to the human body diffused in the atmosphere can be saved and made harmless with energy saving. It is possible to provide a pavement block for environmental purification that is possible and excellent in purification of rainwater, and a method for manufacturing the same.

  The environmental purification pavement block of the present invention is a two-layered environmental purification pavement block having a base layer and a surface layer for eliminating and detoxifying contaminants such as nitrogen oxides and particulate matter diffused in the atmosphere. , Cement paste mixed with cement, water, powdered carbonized material obtained by carbonizing woody biomass, coarse aggregate, fine aggregate, and admixture Generating concrete that forms a base layer of a block in which the cement paste, the coarse aggregate, the fine aggregate, and the admixture are mixed, and the cement paste, the carbonized product, the fine aggregate, and the admixture A mortar mixture constituting the surface layer of the block mixed with is formed, and the concrete is filled in a mold, and the mortar mixture is laminated on the concrete surface of the mold And sea urchin filled, coupled together by clamping the said concrete filled with the mortar mixture, curing the mortar mixture with the concrete obtained by binding, those having a structure formed by solidification.

  Furthermore, the cement is in conformity with the cement standard specified in the Japanese Industrial Standard, or the quality is equal to or higher than this, and the woody biomass is wood such as thinned wood, forest waste, etc. Configuration: The carbonaceous material is configured to be carbonized wood (charcoal).

  In addition, the carbonization temperature of the woody biomass is 400 to 1800 ° C., the carbonized product is charcoal powder, and the charcoal powder has a particle size of 0.1 to 5.0 mm. To do.

  Further, the coarse aggregate is crushed stone or gravel, the fine aggregate is land sand, river sand or sea sand, and the admixture is a standard for concrete admixture as defined in Japanese Industrial Standards. Or the quality is equivalent or better.

  The method for producing a pavement block for environmental purification of the present invention includes a step of kneading cement and water to produce a cement paste, a step of carbonizing woody biomass to obtain a carbonaceous material, and crushing the carbonaceous material To obtain a powdered carbonized product, a step of mixing the cement paste, coarse aggregate, fine aggregate and admixture to produce concrete constituting a base layer of the block, the cement paste and the carbon A step of generating a mortar mixture constituting a surface layer of a block by mixing a chemical compound, a fine aggregate and an admixture; a step of filling the concrete into a mold; and a surface of the concrete of the mold with the mortar mixture A step of filling the laminate so as to be laminated thereon, a step of fastening the filled concrete and the mortar mixture together and integrally bonding, and the combined concrete Over preparative and curing the mortar mixture, which is characterized by comprising a step of solidifying.

  As described above, according to the present invention, a woody biomass such as wood capable of stably supplying raw materials in the local area is used, and a mortar mixture mainly composed of cement and charcoal powder is used as a molding material for pavement blocks. It can be used as a low-cost product and can be manufactured at low cost. It can be used to remove pollutants such as nitrogen oxides and particulate matter that are harmful to the human body and save energy. An excellent pavement block for environmental purification and a method for producing the same can be obtained.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings.

  The pavement block for environmental purification according to the present invention is a pavement block having a two-layer structure having a base layer and a surface layer for eliminating and detoxifying contaminants such as nitrogen oxide (NOx) and particulate matter (PM) diffused in the atmosphere. It is.

  The pavement block for environmental purification of the present invention includes a cement paste in which cement and water are kneaded, a powdered carbonized material obtained by pulverizing a carbonaceous material obtained by carbonizing a woody biomass, a coarse aggregate, and a fine aggregate. Consists of aggregate and admixture.

  The pavement block for environmental purification of the present invention mixes cement paste, coarse aggregate, fine aggregate and admixture to produce concrete, which is used as the base layer of the pavement block. Further, the cement paste, the carbonized material, the fine aggregate, and the admixture are mixed to produce a mortar mixture, which is used as the surface layer of the pavement block. Then, the concrete is filled into the mold, and the mortar mixture is filled into the mold so as to be laminated on the surface of the concrete, and the filled concrete and the mortar mixture are fastened and bonded together, and the combined concrete And mortar mixture is cured and solidified.

  The cement for the environmental purification pavement block conforms to the standard of the cement as stipulated in the Japanese Industrial Standard, or the quality is equal to or higher than this. In this embodiment, it is ordinary Portland cement or white cement.

  Woody biomass of paving blocks for environmental purification is wood such as thinned wood and forest waste, carbonaceous material is carbonized wood (charcoal), and carbonization temperature of woody biomass is 400-1800 ° C .

  Moreover, the particle size of the carbonized material (charcoal powder) constituting the surface layer is 0.1 to 5.0 mm.

The coarse aggregate forming the base layer of the environmental purification pavement block is crushed stone or gravel, and the fine aggregate is land sand, river sand, sea sand and the like.
In addition, the admixture material for the environmental purification pavement block conforms to the standard of the admixture material for concrete as stipulated in the Japanese Industrial Standard, or the quality is equal to or higher than this. In this embodiment, for example, the AE agent Is used.

In the method for producing a pavement block for environmental purification according to the present invention, cement and water are kneaded to produce a cement paste. Then, after carbonizing the woody biomass to obtain a carbonaceous material, the carbonaceous material is pulverized to obtain a powdered carbonized product having a particle size of about 0.1 to 5.0 mm. Next, the cement paste, the coarse aggregate, the fine aggregate, and the admixture are mixed to produce concrete that is the base layer of the block.
On the other hand, cement paste, carbonized material, fine aggregate such as land sand, river sand and sea sand and admixture are mixed to produce a mortar mixture that becomes the surface layer of the block. Concrete is filled into a mold and the mortar mixture is filled into the mold on the surface of the concrete and laminated. Then, the concrete and the mortar mixture are fastened and bonded together to be cured and solidified.

  Pavement blocks for environmental purification crush and classify charcoal, which is a carbonaceous material obtained by carbonizing cement paste, which is a raw material cement and water kneaded, and woody biomass, which is a woody biomass that is the raw material. It consists of charcoal powder, which is a powdered carbonized product, crushed stone, which is coarse aggregate, land sand, which is fine aggregate, and AE agent, which is an admixture. A mortar mixture obtained by mixing cement paste, charcoal powder, land sand, and AE agent is used as a molding material for a paving block.

  As woody biomass, for example, Todo pine thinning from Hokkaido is used. This Hokkaido Todomatsu thinning material is carbonized at a carbonization temperature of 800-1000 ° C using a batch type carbonization device with logs, or this Hokkaido Todomatsu thinning material made into chips and using a continuous type carbonization device. Processing to obtain Todomatsu charcoal.

  The todomatsu charcoal was crushed with a hammer or the like, and then the crushed todomatsu charcoal was further pulverized with a conventional pulverizer. As a result, charcoal powder having a particle size of 0.1 μm to 5.0 mm could be obtained.

  The pulverized charcoal powder was classified to 100 μm or less, 100 μm to 1 mm, and 1 to 5 mm using a classifier.

  The particle size of the charcoal powder was investigated, mainly focusing on the impact on the work environment due to dust scattering, the effect on the miscibility with other materials, and the NOx reduction performance.

  As a result, charcoal powder having a particle size of 0.1 mm or less has a high floating property in the gas phase space due to porosity and low specific gravity, and it is difficult to manage work associated with dust scattering.

  Charcoal powder having a particle diameter of 0.1 to 5.0 mm can minimize dust scattering and can be mixed with cement.

  From the above examination, it was found that the particle size of the charcoal powder is 0.1 to 5.0 mm, and particularly preferably 0.1 to 1.0 mm.

  The cement paste and charcoal powder having a desired particle size were mixed with a mixer to produce a mortar mixture as a molding material for an environmental purification pavement block.

FIG. 1 is a block diagram illustrating a method for manufacturing an environmental purification pavement block according to an embodiment of the present invention.
First, cement, water, crushed stone (coarse aggregate), land sand (fine aggregate), and AE agent (admixture) as raw materials are mixed to produce base layer concrete constituting the base layer of the paving block (step S100). ).

  Next, the todomatsu thinning material 3 which is woody biomass is used as a raw material, and the todopine thinning material 3 is carbonized by a carbonization device to obtain a log-like or chip-like charcoal which is a carbonaceous material (step S101).

  Next, after the log-like or chip-like charcoal is roughly crushed with a hammer or the like, the roughly crushed charcoal is pulverized with a pulverizer and further classified with a sieving machine (step S102). A charcoal powder having a particle size of 0.1 to 0.6 mm is obtained (step S103).

  Next, cement, water, charcoal powder (carbonized material), land sand (fine aggregate), and AE agent (admixture) are mixed to produce a surface mortar (mortar mixture) that constitutes the surface layer of the pavement block (step) S104).

  Next, the base layer concrete is put into a mold and subjected to primary vibration and pressing (step S105).

  Subsequently, surface layer mortar (mortar mixture) is thrown into the mold so as to be laminated on the surface of the base layer concrete, and is subjected to secondary vibration and pressing (step S106).

  Next, the input base layer concrete and surface layer mortar are removed from the mold (step S107).

  Thereafter, the demolded base layer concrete and the surface layer mortar are cured and solidified (step S108) to obtain a pavement block 80 having a two-layer structure which becomes a pavement block for environmental purification.

FIG. 2 is a front view showing a small tunnel test facility for performing a nitrogen oxide and particulate matter reduction performance test using an environmental purification pavement block according to an embodiment of the present invention, and FIG. 3 is a small tunnel test facility and a small tunnel. FIG. 4 is a front view showing a box culvert constituting the small tunnel test facility, and FIG. 5 is a diagram showing the exhaust gas introduction device of FIG. It is a top view expanded and shown.
As a small tunnel test facility A for measuring the reduction performance of pollutants such as nitrogen oxide (NOx) and particulate matter (PM) contained in exhaust gas by a pavement block for environmental purification, FIG. 2 and FIG. As shown, a tunnel T having a total length of 10 m is formed by connecting five concrete box culverts 4 having a height of 2 m, a width of 2 m, and a length of 2 m in series in the longitudinal direction.

  Concrete end wall plates 5 and 6 having observation windows (not shown) are respectively arranged at both ends of the tunnel T of the small tunnel test facility A, and the both end openings of the tunnel T are the end wall plates 5. , 6.

  Between the upper wall 40 and the bottom wall 41 of the box culvert 4, as shown in FIG. 4, a partition plate 44 that divides the inner space left and right is installed between the side walls 42 and 43 along the longitudinal direction of the tunnel T. The internal space of the box culvert 4 of the tunnel T is divided into two equal parts by the partition plate 44.

  One space in the tunnel T formed between the side wall 42 of the box culvert 4 and the partition plate 44 is a blank section B in which the specimen 8 to be a sample is not placed, and the side wall 43 of the box culvert 4 and the partition plate 44 The other space in the tunnel T formed between the two is a sample section S in which the specimen 8 is put.

  As shown in FIG. 5, an exhaust gas introduction pipe of an exhaust gas introduction device 7 that introduces exhaust gas into the blank section B and the sample section S in the tunnel T is inserted into the end wall plate 5 of the small tunnel test facility A. Through holes 50 and 51 are provided.

On one side wall 42 of the box culvert 4, as shown in FIG. 4, detection for measuring the concentration of NO and NO ₂ contained in the exhaust gas introduced into the blank section B in the tunnel T of the small tunnel test facility A tube NO installing a (not shown), and NO ₂ measurement hole 45a, NOx sensor (FIG measuring the NOx concentration in the exhaust gas introduced into the blank Ward B in the tunnel T in a small tunnel test facility a SPM collection device (not shown) for collecting SPM (floating particulate matter) from exhaust gas introduced into blank section B in tunnel T of small tunnel test facility A SPM measuring hole 47a for suctioning to

Further, on the other side wall 43 of the box culvert 4, a detection tube (not shown) for measuring the concentration of NO and NO ₂ contained in the exhaust gas introduced into the sample section S in the tunnel T of the small tunnel test facility A. installation NO, and NO ₂ measurement hole 45b, a NOx sensor for measuring the NOx concentration in the exhaust gas introduced into the sample-ku S in the tunnel T in a small tunnel test facility a (not shown)) to install A NOx measurement hole 46b for carrying out and an SPM measurement hole 47b for sucking the exhaust gas introduced into the sample section S in the tunnel T of the small tunnel test equipment A into an SPM collection device (not shown) for collecting SPM. Is provided.

Small tunnel test facility with NOx concentration meter (APNA-360 manufactured by Horiba, Ltd.) using NO sensor and NO ₂ sensor of detector tube installed in NO, NO ₂ measuring holes 45a, 45b of side walls 42, 43 of box culvert 4 The concentrations of NO and NO ₂ contained in the standard gas introduced into the blank section B and the sample section S in the tunnel T of A were measured.

  Further, by using NOx sensors installed in the NOx measurement holes 46a and 46b provided in the side walls 42 and 43 of the box culvert 4, a NOx concentration meter (APNA-360 manufactured by HORIBA, Ltd.) is used in the tunnel T of the small tunnel test facility A. The concentration of NOx contained in the standard gas introduced into the blank section B and the sample section S was measured.

  Further, the exhaust gas introduced into the blank section B and the sample section S in the tunnel T of the small tunnel test facility A from the SPM measurement holes 47a and 47b provided in the side walls 42 and 43 of the box culvert 4 is an SPM sampling device (not shown). ), And the concentration of SPM contained in the exhaust gas introduced into the blank section B and the sample section S in the tunnel T of the small tunnel test facility A sucked into the SPM sampling device is measured with an SPM densitometer (APDA manufactured by Horiba, Ltd.). -361).

  At one end of the small tunnel test facility A, as shown in FIG. 3, the exhaust gas and air are mixed to adjust the concentration, and the gas is introduced as a standard gas into the blank section B and sample section S in the tunnel T. An exhaust gas introduction device 7 is installed for this purpose.

  As shown in FIG. 5, the exhaust gas introduction device 7 includes a fan F that sucks outside air (air), and a mixer 70 that adjusts the concentration of exhaust gas so that air and exhaust gas are mixed to become a standard gas. And an air introduction tube 71 for introducing the air sucked by the fan F into the mixer 70, and an exhaust gas introduction tube for introducing the exhaust gas discharged to the outside from the exhaust system of the diesel engine of the diesel vehicle into the air introduction tube 71 72. Further, valves V1 and V2 for controlling the flow rate of the exhaust gas whose concentration has been adjusted by the mixer 70, pipe-type air meters (column eye; trademark) C1 and C2 for measuring the flow rate of the exhaust gas whose concentration has been adjusted, and valves Exhaust gas pipes 73a and 74a for introducing the exhaust gas whose concentration is adjusted after passing through V1 into the air flow meter C1, and exhaust gas pipes 73b and 74b for introducing the exhaust gas whose concentration is adjusted after passing through the valve V2 into the air flow meter C2. The hose 75a for introducing the concentration-adjusted exhaust gas from the exhaust gas pipe 73a to the exhaust gas pipe 74a, the hose 75b for introducing the concentration-adjusted exhaust gas from the exhaust gas pipe 73b to the exhaust gas pipe 74b, and the air flow meter C1 Exhaust gas piping 77a for introducing the exhaust gas whose concentration is adjusted after passing through the short pipe 76a into the blank section B in the tunnel T of the small tunnel test facility A , And a exhaust gas pipe 77b for introducing a concentration adjusted exhaust gas passing through the short pipe 76b of Kazeryoukei C2 sample Ward S in the tunnel T in a small tunnel test facility A.

  The fan F is connected to the proximal end of the air introduction cylinder 71, and the mixer 70 is connected to the distal end of the air introduction cylinder 71.

  One end of an exhaust gas introduction pipe 72 is penetrated and connected to the cylindrical main body of the air introduction cylinder 71.

  The valve V1 is disposed between the mixer 70 and the exhaust gas pipe 73a, and the valve V2 is disposed between the mixer 70 and the exhaust gas pipe 73b.

  The exhaust gas pipe 73a and the exhaust gas pipe 74a are connected by a hose 75a, and the exhaust gas pipe 73b and the exhaust gas pipe 74b are connected by a hose 75b.

  The air flow meter C1 is disposed between the exhaust gas piping 74a and the exhaust gas piping 77a, and the air flow meter C2 is disposed between the exhaust gas piping 74b and the exhaust gas piping 77b.

  The exhaust gas pipe 77a is inserted into the through hole 50 provided in the end wall plate 5 of the small tunnel test facility A, and the exhaust gas pipe 77b is inserted into the through hole 51 provided in the end wall plate 5 of the small tunnel test facility A. Has been.

  The actual NOx concentration in the tunnel varies depending on the length of the tunnel, the capacity of its exhaust equipment, the traffic volume, the season, etc., but it is considered to be about 2 ppm in the middle part of the tunnel with a total length of 1000 m or more in the road. Then, the exhaust gas when the diesel vehicle was operated was mixed with air, and the NOx concentration was adjusted to 2 ppm, and used as a standard gas for the NOx and SPM reduction performance test contained in the exhaust gas.

FIG. 6 is a perspective view showing a sample used for measurement of NOx and SPM reduction performance by a pavement block for environmental purification in a small tunnel test facility, (a) is a specimen mixed with charcoal powder, and (b) is charcoal. It is a blank specimen without mixing powder.
First, as a sample, ordinary Portland cement and water were kneaded to produce a cement paste, and cement paste, crushed stone (coarse aggregate), land sand (fine aggregate), and AE agent (admixture) were mixed. The concrete is filled into the mold, and a mortar mixture in which cement paste, charcoal powder, land sand, and AE agent are mixed is laminated so as to be laminated on the concrete surface of the mold, and the concrete and mortar filled in the mold are filled. After the mixture is clamped and bonded together, the combined concrete and mortar mixture is cured and solidified to form a 20 cm square and 60 mm thick pavement block 80 for NOx and SPM reduction performance tests. A specimen 8 was obtained.
At the same time, as a sample, a blank specimen 8 ′ composed of a paving block 80 ′ having the same size as that of the specimen 8 made of only base layer concrete (base layer material configuration) without mixing charcoal powder was also obtained.

The pavement block 80 has a two-layer structure in which a surface layer 82 is integrally formed on the surface of the base layer 81.
In the carbonized material mixing, charcoal powder having a particle size of 0.6 mm or less obtained by pulverizing carbonized wood (todomatsu) is mixed only in the surface layer of the pavement block at a cement weight ratio of 5%.
The layer thickness of the surface layer 82 of the pavement block 80 is 10 mm.

FIG. 7 is a NOx concentration attenuation graph showing the characteristics of the NOx concentration change over time in the exhaust gas introduction stop state to the blank section and the sample section in the tunnel of the small tunnel test facility.
In FIG. 7, the horizontal axis represents time, and the vertical axis represents concentration.
A blank specimen 8 ', which is not mixed with charcoal powder only of the prepared base layer composition, is laid on the entire floor of the blank section B in the tunnel T of the small tunnel test facility A, and the specimen 8 mixed with charcoal powder is subjected to the small tunnel test. It was laid on the entire floor of the sample section S in the tunnel T of the facility A. Next, the exhaust gas adjusted to a NOx concentration of about 2 ppm is introduced into the blank section B and the sample section S in the tunnel T by the exhaust gas introduction device 7, and the exhaust gas introduced into the blank section B and the sample section S in the tunnel T. When the gas reaches an equilibrium state, the supply of the exhaust gas to the blank section B and the sample section S in the tunnel T is stopped, and the results of measuring the NOx reduction effect with a NOx densitometer are shown in FIG.

Gases measured as nitrogen oxides are NO, NO ₂ and NOx.
In blank section B in tunnel T of small tunnel test facility A where specimen 8 is not contained, the NO concentration dropped to about 1.3 ppm after about 60 minutes, but the small tunnel where specimen 8 is contained. In the sample section S in the tunnel T of the test facility A, the NO concentration dropped to about 1.2 ppm, which is lower than the NO concentration in the blank section B in the tunnel T after about 60 minutes.

Further, in blank section B in tunnel T of small tunnel test facility A that does not contain specimen 8, the NO ₂ concentration dropped to about 0.6 ppm after about 60 minutes, but specimen 8 entered. In the sample section S in the tunnel T of the small tunnel test facility A, the NO ₂ concentration decreased to about 0.2 ppm or less, which is lower than the NO ₂ concentration in the blank section B in the tunnel T after about 60 minutes.

  Furthermore, in blank section B in tunnel T of small tunnel test facility A that does not contain specimen 8, the NOx concentration dropped to about 1.8 ppm after about 60 minutes, but specimen 8 is contained. In the sample section S in the tunnel T of the small tunnel test facility A, the NOx concentration decreased to about 1.4 ppm, which is lower than the NOx concentration in the blank section B in the tunnel T after about 60 minutes.

As is clear from FIG. 7, in the blank section B in the tunnel T of the small tunnel test facility A that does not contain the specimen 8, the concrete wall of the box culvert 4 adsorbs NOx, so its concentration decreases. The decrease in NO, NO ₂ , and NOx concentrations was gradual.

However, in the sample Ward S in the tunnel T in a small tunnel test facility A, which contains the specimen 8, after about 60 minutes, _NO, NO 2, NOx concentration with the blank Ward B in the tunnel T NO, NO ₂ , Decreased more rapidly than NOx concentration.
In particular, the reduction rate was found to be greater for the NO ₂ concentration than for the NO concentration.

  Thus, it has been found that simply adding about 5% of charcoal powder to cement provides an excellent environmental purification pavement block that reduces nitrogen oxides (NOx).

  The pavement block in which cement paste containing about 5% of the charcoal powder in the cement weight ratio is laminated on the surface of the base layer exhibits an excellent NOx reduction performance. It turned out that it becomes a NOx reduction performance evaluation test method.

  In addition, you may mix a pigment with a mortar mixture.

The outline | summary of the test result obtained by the pavement block for environmental purification which concerns on the Example of this invention is demonstrated below.
(1) The charcoal obtained by carbonizing Hokkaido Todomatsu thinned wood at around 800 ° C maintained the same NOx reduction performance as that of Honshu cedar and cypress charcoal.
(2) Charcoal can be pulverized with existing technology. The particle size of 0.1 to 5.0 mm can minimize dust scattering and can be mixed with ordinary Portland cement. there were.
(3) Although ordinary Portland cement was mainly used as the composite material, the effect of NOx reduction was recognized to some extent with ordinary Portland cement alone, but it was not remarkable.
However, when ordinary Portland cement was mixed with charcoal powder, the NOx reduction performance approximated to charcoal was maintained within an appropriate blending ratio range.
(4) The molding material using charcoal powder and cement as raw materials exhibited excellent functions for detoxifying NOx and SPM and purifying rainwater.
(5) In a small tunnel test facility using a commercially available box culvert connected, it was possible to perform a test for measuring NOx and SPM reduction performance as a facility close to a full-scale tunnel.
By using an exhaust gas introduction device that mixes exhaust gas from a diesel vehicle with air and introduces it into the tunnel of a small tunnel test facility stably and accurately, a NOx and SPM reduction performance test is performed in a state close to actual conditions. be able to.
(6) As a result of performing a NOx and SPM reduction performance test using a small tunnel test facility on a pavement block formed with a cement and charcoal powder as the main raw material, the pavement block has a remarkable NOx and SPM reduction performance. It was proved.

The block diagram which shows the manufacturing method of the pavement block for environmental purifications based on the Example of this invention. BRIEF DESCRIPTION OF THE DRAWINGS The front view which shows the small tunnel test facility which performs the reduction | restoration performance test of the nitrogen oxide and particulate matter by the pavement block for environmental purification which concerns on the Example of this invention. The top view which shows the arrangement | positioning state of the exhaust gas introduction apparatus which introduces exhaust gas to a small tunnel test facility and a small tunnel test facility. The front view which shows the box culvert which comprises a small tunnel test equipment. The top view which expands and shows the exhaust-gas introduction apparatus of FIG. The perspective view which shows the sample used for the measurement of the reduction performance of NOx and SPM by the pavement block for environmental purification in a small tunnel test facility. The NOx density | concentration attenuation | damping graph showing the characteristic of a temporal change of NOx density | concentration in the exhaust gas introduction stop state to the blank section and sample section in a tunnel of a small tunnel test equipment.

Explanation of symbols

3 Todomatsu thinning (woody biomass)
4 Box culvert 5 End wall plate 6 End wall plate 7 Exhaust gas introduction device 8 Specimen (sample)
8 'blank specimen (sample)
40 Upper wall 41 Bottom wall 42 Side wall 43 Side wall 44 Partition plates 45a, 45b NO, NO ₂ measurement holes 46a, 46b NOx measurement holes 47a, 47b SPM measurement holes 50 Through holes 51 Through holes 70 Mixer 71 Air introduction cylinder 72 Exhaust gas Introduction pipes 73a, 73b Exhaust gas pipes 74a, 74b Exhaust gas pipes 75a, 75b Hoses 76a, 76b Short pipes 77a, 77b Exhaust gas pipes 80 Pavement block 80 'Pavement block 81 Base layer 82 Surface layer A Small tunnel test equipment B Blank section C1, C2 Air flow meter F Fan S Sample section T Tunnel V1, V2 valve

Claims (11)

A pavement block for environmental purification having a two-layer structure having a base layer and a surface layer for erasing and detoxifying pollutants such as nitrogen oxides and particulate matter diffused in the atmosphere,
It consists of cement paste in which cement and water are kneaded, powdered carbonized material obtained by pulverizing carbonaceous material obtained by carbonizing woody biomass, coarse aggregate, fine aggregate, and admixture. Producing concrete constituting a base layer of a block in which the cement paste, the coarse aggregate, the fine aggregate, and the admixture are mixed, and the cement paste, the carbonized product, the fine aggregate, and the admixture. A mortar mixture constituting a surface layer of the mixed block is generated, and the concrete is filled into a mold, and the mortar mixture is filled so as to be laminated on the concrete surface of the mold, and the filled concrete The mortar mixture is fastened and bonded together, and the combined concrete and the mortar mixture are cured and solidified. Environment-purifying paving block that.   The paving block for environmental purification according to claim 1, wherein the cement conforms to a cement standard defined in Japanese Industrial Standards, or has a quality equivalent to or higher than that.   The pavement block for environmental purification according to claim 1, wherein the woody biomass is wood such as thinned wood or forest waste.   The pavement block for environmental purification according to claim 1, wherein the carbonaceous material is charcoal.   The pavement block for environmental purification according to claim 1, wherein the carbonization temperature of the woody biomass is 400 to 1800 ° C.   The paving block for environmental purification according to claim 1, wherein the carbonized material is charcoal powder.   The pavement block for environmental purification according to claim 6, wherein the particle size of the charcoal powder is 0.1 to 5.0 mm.   The pavement block for environmental purification according to claim 1, wherein the coarse aggregate is crushed stone or gravel.   The paving block for environmental purification according to claim 1, wherein the fine aggregate is land sand, river sand or sea sand.   The pavement block for environmental purification according to claim 1, wherein the admixture conforms to the standard of admixture for concrete as defined in Japanese Industrial Standards, or has a quality equivalent to or higher than that. A step of kneading cement and water to produce a cement paste, a step of carbonizing woody biomass to obtain a carbonaceous material, a step of pulverizing the carbonaceous material to obtain a powdered carbonized product, and Mixing the cement paste, the coarse aggregate, the fine aggregate, and the admixture to produce concrete constituting the base layer of the block; and mixing the cement paste, the carbonized material, the fine aggregate, and the admixture. A step of generating a mortar mixture constituting a surface layer of the block; a step of filling the concrete into a mold; a step of filling the mortar mixture so as to be laminated on the surface of the concrete of the mold; and filling The concrete and the mortar mixture are fastened together and bonded together, and the combined concrete and the mortar mixture are cured and solidified. Method for producing environmental clean paving block comprising a degree.

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