JP4193991B2 - Air pollution control paving aggregate - Google Patents

Description

  The present invention relates to an air pollution control paving aggregate (hereinafter simply referred to as “paving aggregate” as necessary), and more particularly to an paving aggregate made of granular wood ceramics made from waste wood. The present invention relates to a paving aggregate to which a photocatalyst such as titanium dioxide is added. “Wood ceramics” refers to “wood, wood material, etc. impregnated with a phenol resin and fired” as described later.

  By using such aggregate for paving, the waste wood can be used effectively, and pollutants such as nitrogen oxides in the atmosphere can be adsorbed to the porous part and then removed by rainwater etc. Furthermore, it is intended to purify the environment by, for example, oxidative decomposition by photocatalytic reactions such as nitrogen oxides and organic pollutants contained in the atmosphere and rainwater.

  In the present specification, the term “waste wood” is used to include not only timber to be incinerated but also various wooden products such as houses, playground equipment, and furniture that are no longer needed.

To recycle waste wood,
・ Use as fuel ・ Chip and use as new construction wood.

  However, the use of new construction wood, etc. overlaps with that of new wood, and the market price of new wood is sluggish and the quality of waste wood is inferior to that of new wood. Without being reused, it is left as it is or incinerated.

  Conventionally, since waste wood is left without being reused, there is a problem in that harmful substances such as carbon dioxide and methane gas are discharged due to the corrosion, causing air pollution.

  In addition, since waste wood is incinerated without effectively using it, there is a problem that resources are wasted.

  In order to make active use of waste wood under such circumstances, it is desirable not to simply recycle but to reuse it in a form that exhibits high added value.

  Therefore, in the present invention, by using substantially granular wood ceramics made from waste wood as a raw material and a photocatalyst (titanium dioxide, etc.) added thereto as a paving aggregate, in addition to recycling of waste wood, air and rainwater The purpose is to purify the environment by removing nitrogen oxides and organic substances contained in the environment.

The present invention solves the above problems as follows.
(1) In granular air pollution countermeasure pavement aggregate made of ceramics made from waste wood (for example, pavement aggregate 11 described later),
As the ceramics,
Wood that has been carbonized by impregnating the waste wood with a phenol resin and firing it, and having both a porous structure that adsorbs atmospheric pollutants as the nature of the wood and the strength as the nature of the phenol resin Ceramics (for example, wood ceramics 11a and 51a described later) are used.
(2) In (1) above,
A photocatalyst such as titanium dioxide (for example, titanium dioxide 11b and 51b described later) is added to the wood ceramic.

  In the present invention, as in the above (1), the waste wood is recycled by using the aggregate for paving made of wood ceramics which is made of waste wood and made of impregnated phenolic resin and fired. In order to purify the environment, pollutants such as nitrogen oxides in the atmosphere are adsorbed on the porous portion of the aggregate for paving. For example, nitrogen oxides adsorbed in the porous portion are dissolved in rainwater and flow. The size and shape of the substantially granular wood ceramics are arbitrary.

  In addition, as described in (2) above, by using an aggregate for pavement in which a photocatalyst such as titanium dioxide is added to substantially granular wood ceramics made from waste wood, waste wood is recycled and the atmosphere Nitrogen oxides and organic pollutants in rainwater are oxidatively decomposed by photocatalytic reaction to purify the environment.

  In the present invention, since the aggregate for air pollution control pavement made of wood ceramics using waste wood as a raw material is used in this way, waste wood is used effectively, and pollutants such as nitrogen oxides in the atmosphere are used. It is possible to purify the environment by adsorbing to the porous portion of the aggregate.

  In addition, because it uses aggregate for air pollution control paving aggregate that added photocatalyst such as titanium dioxide to wood ceramics made from waste wood, the waste wood is used effectively, and nitrogen oxides in the atmosphere and rainwater, It is possible to purify the environment by oxidative decomposition of organic pollutants and the like by photocatalytic reaction.

  Moreover, since the light-receiving surface of the spherical air pollution countermeasure pavement aggregate becomes wide as described later, the effectiveness of the photocatalytic reaction can be further enhanced.

  In addition, the air pollution control paving aggregate is securely fixed to the substantially flat holding member as will be described later, so that the paving aggregate is prevented from shifting due to shear stress, etc. Can be bigger.

  Embodiments (application examples) of the present invention will be described with reference to FIGS. As described above, the present invention exhibits a sufficient environmental purification function even when a substantially granular wood ceramic itself made of waste wood, that is, a photocatalyst such as titanium dioxide is not added.

  In the description of this embodiment, for the convenience of explanation, a substantially granular wood ceramic made from waste wood is added to a photocatalyst.

In these figures,
1 is a multi-layered pavement structure, 11 is a pavement aggregate generated from waste wood, 11a is a spherical and porous wood ceramic (substantially granular wood ceramic) constituting the pavement aggregate, and 11b is a wood ceramic 11a Titanium dioxide and zinc oxide (photocatalyst) applied, 12 is a net (substantially flat holding member) for fixing the aggregate 11 for paving, 12a is an adhesive binder impregnated in the net, 13 is paving A space formed between adjacent pavement aggregates 11 in structure 1,
2 is the base layer,
3 is a guide block,
4 is an asphalt for fixing the bottom surface / peripheral surface portion of the pavement structure 1 to the base layer 2 or the guide block 3;
5 is a mixed pavement structure, 51 is a pavement aggregate generated from waste wood, 51a is a spherical and porous wood ceramic (substantially granular wood ceramics) constituting the pavement aggregate, 51b is a wood ceramic 51a Applied titanium dioxide and zinc oxide (photocatalyst), 52 is sand particles mixed with wood ceramics 51a, 52a is an adhesive binder applied to the surface of the sand particles 52,
Respectively.

  The wood ceramics 11a and 51a are made by impregnating a phenol resin with wood, a woody material, etc. and fired. The wood ceramics 11a and 51a have both a porous structure and an anisotropic structure as properties of wood and an excellent strength as a property of phenol resin. . Pavement aggregates 11 and 51 adsorb contaminants such as nitrogen oxides in the atmosphere into the porous portion. Moreover, the water retention of the aggregate for paving itself is good.

  Titanium dioxide and zinc oxides 11b and 51b are photocatalysts. When sunlight is received, they undergo a photocatalytic reaction and oxidize and decompose the materials in contact therewith. For example, nitric oxide or nitrogen dioxide in exhaust gas discharged from a vehicle is oxidized to nitrate ions, or organic pollutants in rainwater are oxidized and decomposed. This oxidizing power causes bactericidal action and malodor decomposition action.

  For the binders 12a and 52a, for example, existing straight asphalt 60/80, high viscosity modified asphalt (Toughphalt Super (registered trademark)), cement milk, or SBR latex is used.

  For the net 12, an existing blended net (mixing ratio 50:50) made of, for example, glass fiber and cotton fiber, a non-blended net of chemically synthesized fiber, or a blended net of chemically synthesized fiber is used.

FIG. 1 shows a multilayer pavement structure 1 as an application example.
The pavement structure 1 includes a plurality of pavement aggregates 11 attached to a net 12 by an adhesive action of a binder 12a. The height of the illustrated pavement structure 1 is about 3 cm. The individual meshes of the net 12 are large enough to prevent the spherical pavement aggregate 11 from slipping through, for example.

  Each of the spherical pavement aggregates 11 (in each layer) arranged in a lattice shape is securely fixed to the net 12 with the adjacent aggregates in a substantially point contact state.

  Thus, by fixing each pavement aggregate 11 in a point contact state to the net 12 to form a sufficient space 13 between the aggregates, that is, by widening the exposed range of the titanium dioxide 11b, the pavement structure This prevents the pavement aggregate 11 from slipping against the shear stress acting on No. 1, promotes the photocatalytic reaction, and ensures good drainage.

  The degree of clogging of the net 12 after impregnating the binder 12a is at most about 15%, and rainwater passes through the space 13 between the aggregates and the part where the net 12 is not clogged. The structure 1 flows from the surface side to the bottom surface side.

FIG. 2 is an explanatory diagram showing a procedure for generating the paving aggregate 11 from waste wood, and the contents thereof are as follows. The procedure for generating the paving aggregate 51 is the same.
(11) The waste wood medium fiberboard is processed into a cube of about 1 cm square.
(12) While exhausting with an aspirator, this processed body is put into an impregnation tank equipped with an ultrasonic oscillator for about 2 to 4 hours to impregnate with a phenol resin.
(13) While exhausting with a vacuum pump, the processed body impregnated with phenol resin is fired and carbonized in a charcoal furnace. At this time, the temperature is increased from room temperature to 800 ° C. (1-2 degrees) / min. Hold the state at 800 ° C. for about 4 hours and lower to 500 ° C. at 2 degrees / minute. When the temperature falls to 500 ° C., it is naturally cooled.
(14) The carbonized workpiece is crushed with a roller compactor (registered trademark) to obtain a spherical wood ceramic 11a having a particle size of about 2.0 to 9.5 mm.
(15) This wood ceramic 11a is immersed in sol-like titanium dioxide for about 5 minutes.
(16) The wood ceramic 11a after the immersion treatment is centrifuged for about 1 minute to remove the excess titanium dioxide sol on the surface.
(17) The wood ceramic 11a after the removal treatment is vacuum fired at about 200 ° C. for about 1 hour, and a titanium dioxide sol is fixed to the surface to produce the aggregate 11 for paving.

In addition, referring to the pavement test method manual (Japan Road Association 1988), for the wood ceramics 11a before impregnation with titanium dioxide,
・ Specific gravity and water absorption test (JIS A 1109 and 1110 compliant)
-Abrasion weight loss test (JIS A 1121 compliant)
・ Static peeling test (conforms to JPI-5S-27)
・ Aggregate loss test (JIS A 1122 compliant)
The following tests were conducted.

  The specific gravity is an index indicating durability, and the water absorption is an index for determining whether the property is suitable as an asphalt mixture.

  Regarding the surface dry specific gravity and water absorption of the spherical wood ceramics, the respective target values of “2.45% to 3.0%” could not be satisfied.

  The abrasion loss is an index indicating the wear resistance and durability of the coarse aggregate, and the test result satisfies the target value of “30% or less”.

  The static peel test is for confirming the resistance of the heated asphalt mixture to the peel phenomenon. The peeled area ratio of the wood ceramics 11a to be tested is 5%, and it can be said that the film characteristics by straight asphalt are very excellent.

  The aggregate loss test is for determining the durability against freezing and thawing of coarse aggregates and fine aggregates. In the case of wood ceramics 11a to be tested, any size of ceramics with a particle size of 2.36 mm or more that is considered as a target of aggregate for paving satisfies the target value of “12% or less” “7% or less” Met.

  Regarding specific gravity (durability) and water absorption (appropriateness as an asphalt mixture) that did not satisfy the target values among the above test items, the wood ceramics 11a was adhered to the net 12 to ensure the strength of the pavement structure, This is done by reducing the degree of use of asphalt throughout the pavement structure.

FIG. 3 is an explanatory diagram showing a procedure for generating a net 12 for a multi-layer pavement structure as an application example, and the contents thereof are as follows.
(21) Cut into a net 12 having a size of about 50 cm × 50 cm.
(22) The net 12 after cutting is immersed in a straight asphalt 60/80 in a molten state at about 130 to 180 ° C. for about 5 minutes, and the net is impregnated with the binder 12a.
(23) The net 12 after the immersion treatment is placed in a constant temperature bath at about 130 to 180 ° C. to remove excess binder. The final impregnation binder amount is about 100 to 500 g / cm ² .

FIG. 4 is an explanatory diagram showing a procedure for generating the pavement structure 1 of FIG. 1 and the contents thereof are as follows.
(31) Place about 2500 paving aggregates 10 heated to about 140-200 ° C. on the first net 12 and lightly press them from above.
(32) The second net 12 is set on the aggregate 10 for paving.
(33) On the second net 12, about 2500 paving aggregates 10 heated to about 140-200 ° C. are placed and lightly pressed from above.

  Thereafter, the operations (32) and (33) are repeated. The pavement aggregate 11 is heated in order to improve the adhesiveness of the binder 12a. If the amount of the binder 12a is large, this heat treatment may be omitted or the heating temperature may be lowered. It should be noted that the surface layer of the pavement structure 1 may be the pavement aggregate 10 or the net 12, and the number of layers of the pavement structure 1 as a whole is arbitrary.

FIG. 5 shows an on-site construction example (outline) of the multilayer pavement structure 1 as an application example.
Here, asphalt 4 is applied to the base layer 2 excavated from the target area of the pavement, and a pavement structure 1 in the form of a unit is laid on the base layer as many as necessary. )is doing.

  If the pavement structure 1 is prepared in advance, the work on the pavement site is simply arranged and fixed on the asphalt 4 and is simple construction.

  Of course, the pavement structure 1 having a size corresponding to the target area of the pavement may be generated on the pavement site.

FIG. 6 shows a mixed pavement structure 5 of an aggregate 51 for paving and sand particles 52 as an application example.
This is because without using the net 12 in the case of a multilayer type,
・ Making a mixed state of aggregate 51 for pavement in which titanium dioxide or zinc oxide 51b is applied to wood ceramics 51a, and sand particles 52 to which binder 52a is applied,
・ This is laid on the base layer 2 in the same way as in ordinary pavement,
・ Apply rolling pressure to the surface with a road roller, etc.
It is generated by.

  Here, the paving aggregate 51 functions as a coarse aggregate, and the sand particles 52 function as a fine aggregate. The paving aggregate 51 and the sand particles 52 are integrated by the action of the binder 52a.

  Rainwater or the like flows from the surface side of the pavement structure 5 to the bottom surface side through a space where sand particles 52 between the aggregates do not exist.

  The mixed pavement structure 5 may be prepared in advance at a factory or the like and used as in the construction example of FIG.

It is explanatory drawing which shows a multilayer type pavement structure. It is explanatory drawing which shows the procedure which produces | generates the aggregate for pavement from waste wood. It is explanatory drawing which shows the procedure which produces | generates the net | network for multilayer type pavement structures. It is explanatory drawing which shows the procedure which produces | generates a multilayer type pavement structure. It is explanatory drawing which shows the on-site construction example (outline | summary) of a multilayer type pavement structure. It is sectional drawing which shows the mixed type pavement structure of the aggregate for pavement, and a sand grain.

Explanation of symbols

1: Multi-layer pavement structure
11: Aggregate for paving
11a: Spherical wood ceramics (substantially granular wood ceramics)
11b: Titanium dioxide (photocatalyst)
12: Net (substantially flat holding member)
12a: Binder
13: Space 2: Base layer 3: Guide block 4: Asphalt 5: Mixed pavement structure
51: Aggregate for paving
51a: Spherical wood ceramics (substantially granular wood ceramics)
51b: Titanium dioxide (photocatalyst)
52: Sand grain
52a: Binder

Claims (2)

In granular aggregate for paving air pollution measures made of ceramics made from waste wood,
The ceramics are
Wood that is carbonized by impregnating the waste wood with a phenol resin and firing it, and has both a porous structure that adsorbs atmospheric pollutants as the properties of the wood and the strength as the properties of the phenol resin Ceramics,
Air pollution control pavement aggregate characterized by that. A photocatalyst such as titanium dioxide was added to the wood ceramics.
The aggregate for paving against air pollution according to claim 1.

Images