JP2000355913A - Construction method for sound absorbing wall - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the construction method for a sound absorbing wall not only capable of being utilized for the reduction of noises in an exit in a tunnel, the decrease of factory noises, the lowering of a reflected sound in a valley between buildings and an underground parking and the diminishing of traffic noises in a highway or the like but also having an effect such as the removal of a nitrogen oxide(NOX) in an exhaust gas. SOLUTION: A porous light-weight sound absorbing layer is formed by spraying light-weight cement mortar onto the surface of a sound base material, and a finishing material composed of the ultrafine particles of titanium oxide having a photocatalytic function, a platinum catalyst, a palladium catalyst or the like and a ceramic coating agent selected from a sodium silicate, an alkali silicate, a metallic alkoxide, an aqueous silicate and a silicone resin is sprayed on the surface of the sound absorbing layer in 100-1,000 g/m2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention can be used, for example, to reduce noise in tunnels and exits, reduce factory noise, reduce reflected noise in valleys and underground parking lots, and reduce traffic noise in highways and the like. In addition, the present invention relates to a method for constructing a sound absorbing wall having an effect of removing nitrogen oxides (NO _x ) and the like in exhaust gas and having a self-cleaning property.

[0002]

2. Description of the Related Art Conventionally, various soundproof walls and sound absorbing walls have been proposed and implemented as measures against noise in tunnels, factory noise, and traffic noise on expressways. As a construction method of these conventional soundproof walls and sound-absorbing walls, sound-absorbing panels combining glass wool and perforated steel plates are well known, but glass wool has low weather resistance and steel plates are easily rusted, so that overall durability is low. . Aluminum durable panels, aluminum sintered panels, ceramic panels, foam cement panels, etc. are available as durable ones. It is attached and fixed to the wall base material using sub-components and the like.

[0003]

However, the conventional panel-type construction requires a so-called adhesive (base material) or a sub-constituent material to be attached and fixed to the surface of the wall base material in close contact. It took time and cost for construction. In addition, if the wall is uneven or curved, it is necessary to manufacture panels with a surface shape corresponding to it, and if a flat panel is forcibly applied, the thickness of the base material alone is sufficient. As a result, the durability and design properties were significantly impaired. Furthermore, in the construction of a place where external force such as wind resistance acts strongly, it is necessary to rely on a reinforcing material or the like, and these constructions are extremely troublesome.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been proposed in view of the above, and a lightweight cement mortar is sprayed on a surface of a wall substrate to form a porous lightweight sound absorbing layer. A finishing material comprising titanium dioxide having a photocatalytic function on the surface, a ceramic coating agent selected from sodium silicate, alkali silicate, metal alkoxide, aqueous silicate, and silicone resin, and more preferably a platinum catalyst, a palladium catalyst, etc. ~ 1000g /
relates method of constructing the sound absorption walls, characterized in that m ² spray construction.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The lightweight cement mortar used in the present invention is not particularly limited in its raw material and composition, but cement 20 to 60 wt%, lightweight aggregate 25 to 70 wt%, inorganic admixture 10 to 60 wt. %, The organic admixture is 2 to 24 wt%, and the cement / aggregate ratio is 1.
It is desirable to use a lightweight cement mortar of 0 to 4.0 and to set the sprayed thickness to 10 to 100 mm according to the required adsorption performance. That is, in addition to the properties (bending strength, compressive strength), sound absorbing performance, and the like of the porous lightweight sound absorbing layer obtained by spraying, these compositions are non-shrinkable and have good workability. Is set as a value standard. As the lightweight aggregate, one or more of EVA-calcium carbonate expanded aggregate, obsidian expanded granules, pumice, and the like can be used. As the inorganic admixture, one or more of dolomite plaster, a shrinkage reducing agent, and the like can be used. Can be used,
As the organic admixture, at least one of an acrylic fiber, a re-emulsifiable powder resin, a thickener, a shrinkage reducing agent, and a water reducing agent can be used. Further, by using the lightweight cement mortar in the above range, strength, water absorption, workability, and shrinkability are further improved. Specifically, the flexural strength and the compressive strength are high, and a relatively high wall strength can be obtained relatively early, and the durability is improved because the water absorption is small. Further, since the spraying workability by the pump pressure feeding is good, the working efficiency is of course improved. Moreover, since the drying shrinkage of the mortar is small, cracks are less likely to occur. The sprayed thickness can be 10 to 100 mm depending on the required sound absorbing performance.

When the lightweight sound absorbing layer is applied, a net material may be pressed and buried on the surface or inside of the sprayed lightweight cement mortar to improve the strength of the formed lightweight sound absorbing layer. . As the netting material, for example, an alkali-resistant glass fiber net, an aramid fiber net, a vinylon fiber net, and the like can be used, and the material and characteristics thereof are not particularly limited, but preferably have a mass of 40 to 250 g / m ² . With tensile strength of 100kg
Use a net material of f / mm ² or more. Nets in this range
It reduces drying shrinkage, reinforces the tensile strength of the lightweight cement mortar (disperses the tensile stress), prevents cracks, prevents the cement mortar layer from falling off, and ensures safety. In addition, the net material may be embedded in the entire surface or the inner surface of the wall surface, or may be embedded in a partial surface or the inner surface of the wall surface, for example, in a weak portion where a crack or the like is likely to occur. .

Further, a metal lath may be attached to the surface of the wall base material prior to the construction of the lightweight sound absorbing layer. The metal lath is not particularly limited in terms of its shape configuration, material configuration, and the like, but is generally preferably a metal lath rust-proof product, and has a mass of 300 to 4000.
It is desirable to use g / m ² . This metal lath uniforms the coating thickness of the lightweight cement mortar,
As a result, construction management is facilitated and cracks are prevented.

Further, when attaching the metal lath to the surface of the wall substrate, an insertion hole is formed in the thickness direction of the wall substrate, and a hairpin-shaped bifurcated shaft having flexibility is press-fitted into the insertion hole. Then, the metal lath may be loosely fixed (engaged) to the bent bulging portion of the coaxial body, or the metal lath may be fixed with a fixing pin. You may. The bifurcated shaft and the fixing pin can connect the wall base material and the lightweight sound absorbing layer to enhance the integrity, and in particular, the bifurcated shaft is resistant to shrinkage due to temperature changes and wet and dry. The resulting movement is suppressed and absorbed, and safety is ensured.

The titanium dioxide having a photocatalytic function used in the present invention is about 1% less than titanium dioxide used as a white pigment in the fields of paints, plastics, paper, fibers and the like.
/ 20 size and extremely small particle size,
Absorbs light energy (ultraviolet light), generates excited oxygen molecules or highly reactive electrons, reacts with other molecules,
The effect can be increased by utilizing the properties of producing various products to oxidatively decompose organic substances and adding a platinum catalyst, a palladium catalyst or the like. Therefore, there are effects such as sterilization, purification, and deodorization. By mixing this titanium dioxide with a ceramic coating agent and using it as a finishing material, air purification can be achieved. Since this titanium dioxide is already commercially available, it can be easily obtained.

[0010] The ceramic coating agent to be mixed with the titanium dioxide is sodium silicate, alkali silicate,
It is selected from metal alkoxides, aqueous silicates, and silicone resins, and has already been used on building exteriors for the purpose of imparting functions such as weather resistance, nonflammability, contamination resistance, heat resistance, high hardness, and ventilation.

The amount of titanium dioxide to be added to these ceramic coating agents is 10 to 80% by weight, and the amount of these finishing materials sprayed on the surface of the lightweight sound absorbing layer is 100 to 1000 g / m ² , preferably 200 to 1000 g / m ² . 8
00 g / m ² . If less than 100 g / m ² ,
No sufficient effect, i.e. low NO _x removal rate, 1000
If it is more than g / m ² , the NO _x removal rate will not increase any more, but the cost will increase, and moreover, the fine voids on the surface of the lightweight sound absorbing layer will be filled, and the sound absorbing efficiency will be reduced or lost.

It has been proposed to apply titanium dioxide to a sound-absorbing wall for the purpose of preventing air pollution. However, the conventional method is only a method in which titanium dioxide is mixed in a mortar composition, and is not used in sunlight. In order to expose titanium dioxide to the surface of the sound absorbing wall irradiated with (ultraviolet rays), a large amount of titanium dioxide is required. This titanium dioxide is extremely expensive, so that the cost is enormous.
On the other hand, in the present invention, expensive titanium dioxide is blended into the finishing material and spraying is performed, and the amount of titanium dioxide used may be significantly smaller than that in the above-described conventional method. In the case of renovation, repainting of paint is sufficient.

In the present invention, preferably, a metal lath is first fixed to the wall base material of the sound absorbing wall as described above, and more preferably, the metal lath is attached by the bifurcated shaft.
Next, after spraying construction of lightweight cement mortar so that a porous lightweight sound absorbing layer is formed, if necessary, the surface or inside of the entire wall surface, or the surface or inside of a part of the wall surface, for example, on the weak point etc. After the net material is pressed and embedded, a finishing material composed of titanium dioxide having a photocatalytic function and a ceramic coating agent is sprayed extremely thinly. Therefore, in the sound-absorbing wall obtained by the present invention, the light-weight sound-absorbing layer has high sound-absorbing efficiency and reduces noise to the neighborhood, and the finished layer formed on the surface of the light-weight sound-absorbing layer is formed by the nitrogen oxides in the atmosphere. It contributes to the removal of (NO _x ) and the like. Moreover, even if organic substances adhere to the surface of the sound absorbing wall, they are decomposed into lower molecular weight organic substances by the oxidative decomposition action of the organic substance of titanium dioxide contained in the finishing material layer, so that they are removed as the rainwater flows down. With the self-cleaning effect, the surface of the sound absorbing wall is maintained beautifully.
The mesh material embedded in the lightweight sound-absorbing layer can reduce the drying shrinkage of the lightweight cement mortar, reinforce the tensile strength, and suppress cracks. When buried, the tensile stress can be dispersed over the entire surface without partially concentrating the tensile stress. Further, by embedding the net material, the apparent support strength is improved, so that the finishing work can be performed without leaving it for a long time, the workability can be improved, and the construction period can be shortened. In addition, since the movement of the wall surface can be absorbed, rubber elasticity can be given to the outer wall, so that even if a large stress such as an earthquake occurs due to the resonance between the net material and the iron net, cracks reaching the inside Etc. can be prevented from occurring, and safety can be ensured.

[0014]

EXAMPLES [Measurement of Physical Properties] A lightweight cement mortar composition for spraying having the composition shown in Table 1 was prepared, and its physical properties were measured. The measurement of the sound absorption performance is described in detail in [Sound absorption coefficient (normal incidence) measurement] described later.

[Table 1]

[Sound absorption coefficient (normal incidence) measurement] Test method The test was performed in accordance with JIS A 1405 “Method of measuring the normal incidence sound absorption coefficient of building materials by the in-pipe method”. The specimen is 100 × 100mm (1
00 cm ² ). 2. Evaluation Method Using the sound absorption test apparatus shown in FIG. 1, the reverberation time in a normal incidence test tube was measured with and without the test specimen, and the sound absorption coefficient of the material was evaluated from the change in the reverberation time. 3. Measurement case Table 2 shows the measurement cases and their conditions.

[Table 2] 4. Measuring organization Shigen Acoustic Design Office ５． Measurement date and time March 19, 1999 (Fri)

6. Measurement Results From FIGS. 2 to 5, the sound absorption coefficient of the present lightweight cement mortar has a large variation at high frequencies. There was a tendency for the dispersion of the measured values to decrease as the cement / aggregate ratio increased. FIG. 6 shows a comparison between the measured value of the present lightweight cement mortar (cement / aggregate ratio: 2.0 to 3.5) and the measured value of glass wool. As a result, the sound absorption is larger than the glass wool when the cement / aggregate ratio is 3.0 or more. Rate was obtained. From FIG. 7, it is considered from the measurement results of the sound absorbing blocks (including commercially available products) that the sound absorbing performance at low frequencies is increased by increasing the thickness, and the same tendency can be obtained from the present lightweight cement mortar. As shown in FIG. 8, the frequency characteristics of the sound absorption coefficient are such that the sound absorption coefficient rises to the right up to about 1000 Hz, and does not change much beyond that, and is similar to that of a porous material such as glass wool.

[Measurement of NO Gas Removal Ability] Outline of test A simulated pollutant gas (NO 1 ppm) was flowed into a reaction vessel using an ultraviolet-permeable glass material, and a specimen previously set in the reaction vessel was irradiated with ultraviolet rays to continuously collect a certain amount of gas from the reaction vessel outlet. , NO, NO ₂
And by measuring the NO _X, and rated the nitrogen oxides removal performance at that time. As a comparison, a test was performed using a commercially available NO _X purification block.

2. Test Apparatus The outline of the test apparatus is as shown in FIG. The simulated pollutant gas is a standard gas of nitric oxide (2 ppm: manufactured by Nippon Sanso Corporation).
And pure air (A standard: manufactured by Nippon Oxygen Co., Ltd.) are mixed in an equal amount to produce 1.5 L / air of air containing 1 ppm of nitric oxide.
At a flow rate of 1 min. Irradiation ultraviolet light was obtained by adjusting the distance between the specimen and the black light using a black light (manufactured by Toshiba Corporation), and the longer wavelength ultraviolet light (UV
-A) adjust the intensity of the UV intensity meter (UV-MONITOR M
(S-211-I type: manufactured by Eiko Seiki Co., Ltd.). The upper surface of the reaction vessel is made of glass that transmits ultraviolet light, the side surface is made of acrylic, and the lower surface is a wooden rectangular parallelepiped. The upper surface (glass surface) is removable. Side (short side)
Has a gas inlet and an outlet on the opposite side. All gas lines including joints were made of Teflon. The automatic nitrogen oxide measuring device is a measuring device by the chemiluminescence method based on ozone generation (APNA360 type:
(Horiba, Ltd.) was measured using a two-pen type pen recorder (LR4100E: Yokokawa Electric Co., Ltd.), and continuous measurement was performed during the test. Two sets of devices were prepared, and the test was performed in two series.

3. Test conditions The measurement conditions of the removal ability measurement test using each specimen are as shown in Table 3. The temperature in the laboratory was set at 20 ° C by air conditioning control by an air conditioner, and the humidity was not adjusted. The supply gas to the apparatus was set to 2 ppm of nitric oxide, and the supply gas amount was set to 1.5 L / min. The UV intensity is about 1 mW / cm ² (when cloudy outdoors) and about 4 mW / cm ² (when sunny outdoors). A test was performed on the material coated on the flat surface. However, the comparative specimen was a smooth surface only. In addition, tests were performed on the wall material specimens that were present, those that had been wet all over by spraying (wet state), and those that had been dried with a dryer at 105 ° C for 24 hours (dry state). However, only the improved specimens were used as they are.

[Table 3]

4. Specimen The outline of the specimen used for the test is shown below. The test was performed on 22 cases according to the combination of the specimen and the test conditions. Table 4 shows the test conditions of the 22 cases. Photocatalyst-coated glass plate (= Test No. 1, 11) Photocatalyst paint: “Silk Wave H-Ti” (manufactured by Green Chemie) and “MSA-u1” (manufactured by Nissan Research Co., Ltd.)
Using a type of paint, the surface was processed on a glass substrate surface without adsorption of NO (nitrogen monoxide) gas. Any paint could be sprayed on the wall material. Both are coating materials containing functional titanium dioxide. Size of glass plate: 200 mm x 100 mm (thickness t: 8 mm) Spraying wall material (manufactured by Fujikawa Building Materials Co., Ltd.) (= Test No. N
o.2 to 6, 12 to 16) Sound-absorbing substrate: The "sprayed sound-absorbing material (cement / aggregate ratio = 2.5)" in the above [Sound absorption coefficient (normal incidence) measurement] was used. As described above, it has been confirmed that the material has a sound absorbing performance equal to or higher than that of glass wool. Photocatalytic paints: “Silk Wave H-Ti” (manufactured by Green Chemie) and “MSA-u1” (manufactured by Nippon Kensha Co., Ltd.)
The surface of the sound-absorbing substrate was processed (spray application amount: 350 g / m ² ) using various kinds of paints. Improvement of photocatalytic paint (= Test No. 7, 8, 17, 18) The amount of titanium dioxide was set to 50 wt%. Improvement II of photocatalytic paint (= Test No. 9, 10) The amount of titanium dioxide was set to 70 wt%. In comparison specimen (= test Nos No.19~22) NO _x removal performance verified, photocatalytic building materials under test construction application (commercially available NO _X purification block) and the wall Zaika. The shape is the same as above. The difference is that the wall material is a porous mortar, and the photocatalytic processing of the surface is baking.

[Table 4]

5. Test Results The time-dependent changes in the nitrogen oxide outlet concentration after ultraviolet irradiation in 22 cases performed for each specimen are as shown in the graphs (FIGS. 10 to 20) for each case. The initial adsorption to specimen for each test case, the _outlet-side NO _x minimum, maximum N
O _x removal rate, the NO _x minimum arrival time are shown in Table 5-7. Also, shown respectively silk wave, the results of tests conducted under the same conditions among the results of the MSA-u1 and comparative specimen (commercially available NO _X purification blocks) in the same graph (Figure 10-19).

[Table 5]

[Table 6]

[Table 7]

1. Adsorption on test specimens
From the results of the test pieces using the glass plates Nos. 1 and 11, neither silk wave nor MSA-u1 was adsorbed on the catalyst. Further, when the specimen is set in a reaction vessel and a simulated contaminant gas is supplied, initial adsorption to the wall material occurs before irradiation with ultraviolet rays. When ultraviolet light is irradiated in this state, the concentration decreases from the supply concentration minus the amount of adsorption. At first glance, it seems that the effect of the ultraviolet rays is reduced only from the concentration obtained by subtracting the adsorbed amount from the supply concentration. However, as shown in FIG. 20, after a certain period of time has elapsed after the irradiation with the ultraviolet light and the maximum removal ability was exhibited, the irradiation of the ultraviolet light was stopped and the recovery of the concentration at the outlet of the reaction vessel was observed. Recovered. Then, when further irradiating with ultraviolet light, it showed the same value as the initial NO _x minimum value, and it was confirmed that the removal ability of the specimen was judged to be a decrease from the supply concentration and no problem irrespective of the initial adsorption amount. Was.
Therefore, in this test, the reduction from the supply concentration was treated as the removal regardless of the initial adsorption amount to the wall material.

2. Specimens of the NO _x removal capability 1) UV intensity ^{(1mW / cm 2, 4mW /} cm 2) UV intensity, silk wave (Test No. No.2 and 3), MSA-u1 (Test No. No.12 and 13) In both cases of the commercial NO _X purification block (Test No. 19 and Test No. 20), 4 mW / cm ² (Test No. 3, Test No. 3) than 1 mW / cm ² (Test No. ^2, 12, 19). 13, 20) who has had a higher NO _x removal capability.

2) Specimen state (current, wet, dry state) The specimen state was silk wave (Test No. 3,
When using 4,5), dry (Test No. No.5) indicates the highest 57% NO _x removal capability, then current (Test No. No.3) and the 49% of the NO _x removal capability it is, it has been a NO _x removal capability of 15% in the wet state (test No. No.4). MSA-u1 (Test No. 13, 14, 15)
When using, shows the highest 37% is NO _x removal capability wet (Test No. No.14), then dry (test No. No.15, NO _x removal performance: 35%), current (Test No. N
o.13, NO _x removal performance were: the order of 30%). A commercially available NO _X purification block of a comparative specimen (test numbers No. 20, 21,
For 22), current (Test No. No.20) indicates the highest 76% is NO _x removal capability, then dry (test number N
o.22, NO _x removal performance: 69%), wet (Test No. N
o.21, NO _x removal performance: has become the order of 15%), the difference due to the coating film was observed.

3) Surface coated with photo-oxidation catalyst coating (irregularity, smooth surface) The surface coated with photo-oxidation catalyst coating was silk wave (test number N
o, 3,6,7,8,9,10), spray wall material (cement / aggregate ratio = 2.5), paint improvement (cement / aggregate ratio)
Aggregate ratio = 2.5) and towards the smooth surface in any of the paint improvements II has become a higher or same degree NO _x removal capability,
It was better than the uneven surface. However, when MSA-u1 (test numbers Nos. 13, 16, 17, 18) was used, the sprayed wall material (cement / aggregate ratio = 2.5) had better paint improvement (cement / bone). wood ratio = 2.5) in which towards the uneven surface becomes higher NO _x removal capability respectively, the tendency of the coated surface did not grasp.

4) Evaluation of NO _x removal ability As described above, when comparing the performances of the respective coating films, the highest NO _x removal ability was attained by the silk wave having a UV intensity of 4.25 mW / cm ² and the paint improvement II. , Current condition, smooth surface (Test No. 10)
And the NO _x removal ability was 83%. Comparison in the same conditions Specimen commercially NO _X purification block (Test No. No.20)
The NO _x removal capability of nitrogen oxides was 76%.

[Execution Execution Test] As shown in FIG. 21, a metal lath 2 is attached to the surface of the wall substrate 1 by using fixing pins 3 (or a hairpin-shaped bifurcated shaft 4 having flexibility). Net 6 in lightweight cement mortar 5
And a finishing material 8 containing titanium dioxide was applied to the surface of the lightweight sound absorbing layer 7 thus formed. As the lightweight cement mortar and the finishing material, those used in the above test were used. By using the metal lath, the coating thickness of the lightweight cement mortar could be easily made uniform, and a beautiful sound absorbing wall without cracks or the like was obtained.

Although the present invention has been described based on the embodiments, the present invention is not limited to the above-described embodiments, and may be implemented in any manner unless the configuration described in the claims is changed. Can be.

[0029]

As described above, according to the present invention, since a sound absorbing wall is constructed by spraying a material having excellent sound absorbing properties by the spraying method, the construction cost is low. In addition, since the material itself is lightweight and has excellent adhesion, a measure for preventing peeling is simple. Curved surface is free by spraying method. The sound absorption can be further improved by adding a thickness. Further, the sound absorbing wall obtained by the present invention has a lightweight sound absorbing layer having a high sound absorbing efficiency to reduce noise to the neighborhood,
Finish layer formed on the surface of the light absorbing layer, contributes to the removal of nitrogen oxides in the atmosphere (NO _X) and the like. In addition, when organic matter containing soot and the like adheres to the surface of the sound absorbing wall, the appearance is extremely impaired, but the sound absorbing wall according to the present invention adheres due to the action of titanium dioxide contained in the finishing material layer. The organic matter is decomposed into lower molecular weight organic matter, and the adhering components can be removed as the rainwater flows down (self-cleaning effect), so that the surface of the sound absorbing wall is maintained beautifully.

[Brief description of the drawings]

FIG. 1 is a flow diagram schematically showing a sound absorption test apparatus used for sound absorption measurement.

FIG. 2 is a graph showing test results of sound absorption coefficient measurement.

FIG. 3 is a graph showing test results of sound absorption coefficient measurement.

FIG. 4 is a graph showing test results of sound absorption coefficient measurement.

FIG. 5 is a graph showing test results of sound absorption coefficient measurement.

FIG. 6 is a graph showing test results of sound absorption coefficient measurement.

FIG. 7 is a graph showing test results of sound absorption coefficient measurement.

FIG. 8 is a graph showing test results of sound absorption coefficient measurement.

FIG. 9 is a flow diagram schematically illustrating a test apparatus used for measuring NO _X gas removal ability.

10 is a graph showing the test results of the NO _X gas removal capability measurement.

FIG. 11 is a graph showing a test result of NO _x gas removal ability measurement.

12 is a graph showing the test results of the NO _X gas removal capability measurement.

FIG. 13 is a graph showing a test result of NO _x gas removal ability measurement.

14 is a graph showing the test results of the NO _X gas removal capability measurement.

15 is a graph showing the test results of the NO _X gas removal capability measurement.

16 is a graph showing the test results of the NO _X gas removal capability measurement.

FIG. 17 is a graph showing a test result of NO _X gas removal ability measurement.

18 is a graph showing the test results of the NO _X gas removal capability measurement.

FIG. 19 is a graph showing a test result of NO _X gas removal ability measurement.

20 is a graph showing the test results of the NO _X gas removal capability measurement.

FIG. 21 is a side sectional view showing the structure of a sound absorbing wall formed in an execution test.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiroshi Yamauchi 2-5-8 Kitaaoyama, Minato-ku, Tokyo Co., Ltd. Intra-company group (72) Inventor Yasutaka Ueda 2-5-8 Kitaaoyama, Minato-ku, Tokyo Stock Company In-house group (72) Inventor Takayuki Masuda 2-5-8 Kita-Aoyama, Minato-ku, Tokyo Co., Ltd. In-house group (72) Inventor Susumu Harada 13-family Torihama-cho, Kanazawa-ku, Yokohama-shi, Kanagawa Prefecture Inside Fujikawa Building Materials Industry Co., Ltd. (72) Inventor Hidenori Kojima 13-family Torihama-cho, Kanazawa-ku, Yokohama-shi, Kanagawa Prefecture F-term (reference) 2D001 AA01 CB01 CD02 DA08 2E001 DF04 DH23 EA02 FA04 FA30 GA06 GA32 HA07 JA20 KA01 LA16 MA01

Claims (5)

[Claims] 1. A porous lightweight sound absorbing layer is formed by spraying a lightweight cement mortar on a surface of a wall base material, and further, titanium dioxide having a photocatalytic function is formed on the surface thereof, sodium silicate, alkali silicate, 100-1000 g of a finishing material composed of a metal alkoxide, an aqueous silicate, and a ceramic coating selected from silicone resins
/ M ^{2 A} method for constructing sound-absorbing walls, characterized by spraying. 2. The composition of the lightweight cement mortar is 20 to 60 wt% of cement, 25 to 70 wt% of lightweight aggregate, 10 to 60 wt% of inorganic admixture, and 2 to 24 wt% of organic admixture.
The method according to claim 1, wherein the cement / aggregate ratio is 1.0 to 4.0 in%. 3. The method according to claim 1, wherein, when the lightweight sound absorbing layer is applied, the net material is buried by pressing the net material on the entire surface or inside of the wall surface, or on the surface or inside of a part of the wall surface. Construction method of sound absorbing wall. 4. The method according to claim 1, wherein a lightweight sound absorbing layer is formed after attaching a metal lath to the surface of the wall base material. 5. An insertion hole formed in a thickness direction of a wall base material,
A hairpin-shaped bifurcated shaft having flexibility is press-fitted and a metal lath is loosely fixed to the bent bulging portion of the coaxial body, or the metal lath is fixed with a fixing pin. The construction method of the sound absorbing wall according to claim 4.