JP2003089558A - Lightweight aggregate for mortar - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lightweight aggregate for mortar, having excellent strengths and excellent resistances to alkalis and water permeability. SOLUTION: The lightweight aggregate for mortar is obtained by coating foamed glass with an organic polymer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lightweight aggregate for mortar, and more particularly to a lightweight aggregate for mortar using foamed glass and a lightweight mortar containing the same. Included mortar (concrete), lightweight spray mortar (concrete), plastered premix lightweight mortar (concrete), etc.

[0002]

2. Description of the Related Art Conventionally, non-cement type hard urethane foam is used for non-cement type cement and air mortar type for lightweight backfilling material, embankment material and gap filling material for filling voids on the backside of tunnel lining concrete. Is used.

These materials are generally expensive, and when used in large quantities for backfill materials, they are extremely economically unreasonable. Moreover, the compressive strength is not sufficient, which is 1.5 N / mm ² or less. Moreover, in the case of urethane foam, it is difficult to control the specific gravity and strength of the urethane because the expansion ratio changes with temperature and humidity. Moreover, since the raw material monomers of urethane are mixed at the filling port and polymerized to form a polymer, unpolymerized monomer which is a toxic substance is liable to remain, and there is a possibility that secondary pollution may occur especially in a place where water is flowing.

On the other hand, air mortar has low strength, and the air tends to disappear during kneading and transportation (pumping, etc.), and it is difficult to control the specific gravity. In particular, in the case of underwater construction, even if a thickener is used, the air may dissolve in water and disappear, making it impossible to manage as designed. Depending on the water depth, a phenomenon such as a volume decrease due to the pressure occurs, and there is a drawback that the management of the unit volume mass is unstable and the strength management is difficult.

[0005]

Mortar and concrete using a lightweight aggregate (foam glass) manufactured from waste glass is about to be applied to various structures. However, mortar using waste glass has a problem of long-term durability. The reason is that glass is generally easily deteriorated by an alkaline component in cement, and the water absorption rate of the foam glass itself is extremely high. For the purpose of improving the alkali resistance of glass, it has been proposed to coat foam glass with viscous mineral and use it in concrete or mortar, but it has not been possible to improve the high water absorption of foam glass. Thus, a method of using the foamed glass after improving its durability is under development.

From the viewpoint of the required performance of the structure, the lightweight mortar may require the mortar and the concrete itself to be further lightweight and have high strength. For example, it can be said that it is rational construction to place mortar and concrete by spraying method, but economical and durable lightweight aggregate that can be used for mortar and concrete spraying method has not been developed. .

[0007] Therefore, there is a demand for a lightweight aggregate for mortar which is excellent in strength and is also excellent in chemical resistance such as alkali resistance and water permeability, and a lightweight mortar using the same.

[0008]

Means for Solving the Problems As a result of intensive studies on the above problems, the present inventor has found that the excellent properties of the foamed glass lightweight aggregate can be utilized by coating the foamed glass lightweight aggregate with an organic polymer. They discovered and succeeded in producing a lightweight mortar with excellent strength, chemical resistance, and water permeability.

That is, the present invention provides a lightweight aggregate for mortar, which is formed by coating foam glass with an organic polymer, and a method for producing the same. Further, the present invention provides a mortar containing the lightweight aggregate. It should be noted that the term "mortar" as used herein is intended to include concrete.

In the present invention, by coating the foamed glass lightweight aggregate with the organic polymer, it is possible to avoid the risk that the silica component in the glass is eluted by the strong alkali coming from the cement. Further, the water-permeable resistance is also improved by coating the foam glass aggregate with the organic polymer. Specifically, by coating the glass aggregate with an organic polymer, the water absorption of the aggregate can be improved to about 40% or less before coating.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION As the material of the foamed glass, any material used for glass can be widely used. As a typical example,
Soda lime glass, potash glass, borosilicate glass,
Lead crystal glass, optical glass, crystallized glass, etc. are available. Reusing these waste glasses is advantageous for both cost and environmental reasons. According to the present invention, glass that has a high glass melting temperature and is difficult to recycle, such as Pyrex (registered trademark) glass, can be reused. Of these, soda lime glass is particularly preferable because it can be obtained in large quantities from inexpensive waste such as plate glass, bottle glass, and tube glass.

The density of the foam glass is usually 1 g / c.
It is less than m ³ , and preferably in the range of 0.6 to 0.8 g / cm ³ . The particle size of the foam glass is usually 0.05 to
It may be 25 mm, preferably 0.1 to 10 mm, more preferably 0.2 to 5.0 mm.

The foamed glass preferably has a structure in which fine closed cells are aggregated in order to exhibit high strength. Methods for producing such foam glass are well known in the art.
For example, it can be obtained by pulverizing the above glass raw material to have a particle size of 5 to 500 μm, sieving and mixing glass powder with a foaming agent and an additive, granulating, firing, and slowly cooling. it can. The effervescent agent is calcium carbonate,
Barium carbonate, magnesium carbonate, silicon carbide, borax,
There are boric acid, boron oxide, carbon and the like. The firing temperature is
Usually, the temperature is equal to or lower than the softening point of glass and is determined according to the glass composition. Specifically, it is in the range of 600 to 1200 ° C. In addition, commercially available foam glass such as G Light (produced by Crystal Clay Co., Ltd.) may be used.

As the organic polymer for coating the foam glass, a natural or synthetic polymer conventionally known in the field of organic chemistry can be used without particular limitation. Typical examples are acrylic resin, MMA resin, epoxy resin, vinyl chloride resin, polyester resin, urethane resin, silicone resin, alkyd resin, aminoalkyd resin,
Synthetic resins such as vinyl acetate resin, fluororesin, phenolic resin, polyvinylidene chloride; natural resins and oils such as rosin, shellac, linseed oil, coconut oil; cellulose derivatives; natural rubber and styrene-butadiene rubber (SBR), chloride Rubber,
Examples thereof include synthetic rubbers such as silicone rubber, acrylic rubber, and fluororubber; and silane coupling agents such as epoxysilane and acrylicsilane. These organic polymers may be used alone or in combination of two or more kinds. In particular, it is desirable to select a resin having a hardness as high as possible among acrylic resin, MMA resin, epoxy resin, vinyl chloride resin, polyester resin, synthetic rubber and the like.

The morphology of the organic polymer in coating the glass aggregate varies depending on when and where the coating is performed. That is, there is a case where the glass aggregate is coated at the mortar construction site, a case where the glass aggregate is subjected to the coating treatment before being brought into the site, and the like. The coating of foam glass at the mortar construction site is advantageous in terms of work convenience.

Therefore, when the glass aggregate is coated at the mortar construction site, the form of the organic polymer may be a solvent type or an emulsion type, but is preferably an emulsion type, and particularly preferably a commercially available polymer emulsion for cement admixture. It is in the form.

On the other hand, when the glass aggregate is subjected to a coating treatment before being brought into the site, or particularly when acid- or alkali-resistant chemical durability is highly required, the form of the organic polymer may be a solvent type. Although it may be an emulsion type, particularly preferably a solvent-based epoxy resin,
Alternatively, a resin having high hardness such as MMA resin is selected.

The organic polymer may be in the form of a mixture of the organic polymer and a hydraulic inorganic material such as cement, silica fume, fly ash and slag. By using this mixture, it is possible to improve the adhesion between the foamed glass lightweight aggregate and the cement containing mortar as a main component. In this case, the organic polymer used is in the form of an emulsion. The mixing ratio (mass ratio (P: C)) of the organic polymer “P” and the hydraulic inorganic material “C” is usually 1
00: 0.5-50.0, preferably 100: 1.0-
It is in the range of 20.0. If the mixing amount of the hydraulic inorganic material is too small, the above effect cannot be obtained. On the contrary, if the mixing amount is too high, the strength of the lightweight aggregate is deteriorated due to the invasion of the alkaline component from the hydraulic inorganic material.

When the organic polymer is in the form of an emulsion, the amount of the organic polymer used is usually 0.5 to 10.0%, preferably 1.0 to 10.0, relative to the mass of the foam glass aggregate.
It is 7.0%. On the other hand, when the organic polymer is in the form of a mixture of the organic polymer and the hydraulic inorganic material, it is usually 1.0 to 30.0%, preferably 3.0 to 20.% with respect to the mass of the foam glass aggregate. It is 0%.

The foamed glass aggregate of the present invention is obtained by coating foamed glass with an emulsion or solution of an organic polymer, removing excess emulsion or solution using a centrifuge, etc. Obtained by heating and drying. The coated resin may penetrate into the foam glass. Further, in order to prevent the foamed glass from adhering to each other and preventing agglomeration, the surface of the foamed glass coated with the organic polymer may be further coated with powder such as a hydraulic inorganic material. The coated and optionally dried foamed glass lightweight aggregate can be stored until on-site construction.

[0021] Another aspect of the present invention relates to a mortar containing a hydraulic inorganic material and a foamed glass lightweight aggregate coated with the organic polymer.

The mortar of the present invention is in the range of cement mortar, but the unit volume mass of the mortar is 0.7 to 1.8 by using the foam glass for the fine aggregate having a low density.
Within the range of t / m ³ , the same density as conventional foamed urethane and air mortar can be realized. In addition, when applied to backfill fillers, the compressive strength is 1% of that of conventional air mortar.
It is possible to increase it to 20 N / mm ² or more, which is about 0 times. Furthermore, when it is used as a spraying method or a plastered premix mortar, a high strength of about 40 N / mm ² is obtained.

The hydraulic inorganic material includes ordinary Portland cement, early strength Portland cement, super early strength Portland cement, moderate heat Portland cement, low heat Portland cement, and other Portland cement, ultrafast hardening cement, alumina cement, cement-based expansive material, gypsum. Etc. are selected.

For the mortar, a hydraulic inorganic material is used.
Used at 0-800 kg / m ³ and 20 lightweight aggregates
It is used in the range of 0 to 550 kg / m ³ . The mixing ratio of the hydraulic inorganic material and water is usually 100: 30 to 5 by mass ratio.
It is 5.

The mortar of the present invention includes a hydraulic inorganic material,
In addition to the lightweight aggregate, water and air particles, lightweight aggregates, admixtures, admixtures and the like other than the present invention can be added within a range that does not impair the effects of the present invention. Examples of the admixture include silica fume, fly ash, artificial fine powder such as slag powder, and non-hydraulic fine powder such as stone powder. Admixtures include AE agents, water reducing agents, hardening accelerators, hardening retarders, quick setting agents, waterproofing agents, separation reducing agents, foaming agents, rust preventive agents,
Examples include fluidizing agents.

When the mortar is required to have chemical resistance to acidic soil and the like, a polymer emulsion for cement admixture may be added to the mortar. The amount used is 4 parts by weight of the polymer emulsion based on 100 parts by weight of the hydraulic inorganic material.
˜27 parts by weight (resin solid content concentration of polymer emulsion is 45%), that is, polymer emulsion resin solids content is 2 to 12 with respect to 100 parts by weight of the hydraulic inorganic material.
Parts by weight. The proper blending ratio of these can be appropriately determined within the technical level of the ordinary level of those skilled in the art in consideration of the chemical resistance, the water permeability, etc. of the target lightweight mortar.

By mixing about 30% by volume of air of ordinary air mortar into the mortar of the present invention, the specific gravity is 1.0.
It is also possible to produce the following ultra-lightweight and high-strength mortar.

When the back filling material is filled in the cavity such as the back surface of the tunnel, filling the unnecessary portion with the material becomes a problem from the viewpoint of design and cost. Segregation reducing agent,
By changing the compounding conditions of the fluidizing agent, the hydraulic inorganic material, and the like, it is possible to prepare a thixotropic filling material having appropriate fluidity that can limit the filling range.

If the density of the lightweight aggregate is too low for water to separate and float, a segregation reducing agent is used. Separation reducing agents include cellulosics such as methyl cellulose, ethyl cellulose, and hydroxyethyl cellulose, PWA
There are polymer materials such as (polynitrile vinylidene acrylate), polyacrylamide, and polysaccharides. The amount of the separation reducing agent used varies depending on the construction conditions such as the case where the intended filling site of the lightweight mortar is underwater and the case where self-leveling property is required. Usually, in the case of a cellulosic type, the mass ratio of hydraulic inorganic material: separation reducing agent is 100: 0.1-0.
5 is used, and in the case of PWA (solid content concentration 2%), 10
It is used in the range of 0: 0.1 to 0.3. Both separation reducing agents may be used in combination.

By adding reinforcing fibers such as glass fibers, steel fibers, synthetic fibers, cellulose fibers and carbon fibers to the mortar of the present invention, it is possible to apply it as a thickened cross-section restoration material. Further, by mixing a curing accelerator acting on the hydraulic inorganic material with a nozzle, it is possible to spray the flame-retardant fireproof coated mortar.

The mortar of the present invention can be obtained by kneading each of the above components using a known method and apparatus. As the kneading device, specifically, a weight mixer such as a drum mixer or a tilting mixer; a forced kneading mixer such as a pan mixer or a pug mixer; an omni mixer or the like is used. The kneading time and other kneading conditions may be appropriately adjusted while observing the state of kneading by mortar trial kneading.

Mortar using the lightweight aggregate of the present invention is
The strength of the mortar of the present invention is higher than that of the conventional one, and in addition, the mortar of the present invention does not require a weight-reducing method such as mixing air by using a foaming agent, etc. Properties such as density change during mixing, transportation and driving do not change. Therefore, the lightweight aggregate of the present invention includes a lightweight backfill material, a lightweight embankment material, a gap filling material, a thickened cross-section restoration material, a lightweight secondary product, a flame-retardant fireproof coating material by a spraying method, and a sprayed concrete (mortar). It can be used for multipurpose purposes such as plaster for concrete (mortar).

[0033]

The present invention will be described in more detail with reference to the following examples. In addition, unless otherwise indicated, a part means a weight part. [Example 1] -Pre-coating of foam glass aggregate and measurement of water absorption rate-After measuring a predetermined amount of commercially available foam glass (trade name G light No. 2 (manufactured by Crystal Clay)) and putting it in a bag-shaped net The net was immersed in a container containing a sufficient amount of acrylic emulsion (TJ emulsion, trade name, manufactured by Takeda Pharmaceutical Co., Ltd., solid content concentration 45%) for about 2 minutes. After that, the net was taken out to remove excess polymer emulsion and then centrifuged for 5 minutes. The lightweight aggregate thus obtained was pre-coated with a polymer emulsion in a mass ratio of 6% with respect to the lightweight aggregate. Density of 0.65 g / cm ³ was lightweight aggregate before treatment became 0.68 g / cm ³ after treatment.

The 24-hour water absorption of the coated foam glass aggregate itself was measured according to JIS A 1134. For comparison, the water absorption of the aggregate not coated with the polymer emulsion was also measured. The water absorption rate of 11.2% before the surface treatment with the polymer emulsion was 4.9%, which was about half the water absorption rate by the treatment.

Example 2 Pressurized Water Absorption Test of Coated Foam Glass Lightweight Aggregate-To investigate the change in water absorption characteristics due to the coating of light weight aggregate, after the foam glass lightweight aggregate was coated with an organic polymer. The water absorption under pressure was measured. Acrylic resin emulsion (total solid content concentration 45%),
Polymer cement milk which mixed solvent type epoxy resin, acrylic emulsion (P) and hydraulic inorganic material (C)
Three types (P: C = 2: 1) were used. First, according to the same procedure as in the pre-coating of Example 1, the above organic polymer was applied so as to be the coating resin / aggregate shown in Table 1. Next, water addition pressure was set to 1 kgf / cm ² , pressure holding time was set to 10 minutes, the lightweight aggregate was put into a non-drained container, and a water absorption test was conducted. Table 1 shows the measurement results of water absorption when each material was coated.

[0036]

[Table 1]

FIG. 1 is a graph of the results of Table 1. As can be seen from FIG. 1, the water absorption rate tends to decrease as the coating resin amount increases.

[Example 3] -Alkali resistance test of coated foamed glass lightweight aggregate-To check to what extent alkali resistance is improved by coating the lightweight aggregate, the coated lightweight aggregate Was immersed in a 5% NaOH aqueous solution, and the mass reduction rate was measured after a predetermined period. Acrylic emulsion was used for coating. The mass reduction rate is
After soaking for a specified period, remove the aggregate from the aqueous solution and
This was calculated by washing with water on a μm sieve, wiping off the remaining surface water of the aggregate, and measuring the mass at that time.
Table 2 shows the measurement results of the mass reduction rate of the lightweight aggregate immersed in the 5% NaOH aqueous solution.

[0039]

[Table 2]

FIG. 2 is a graph of the results of Table 2. As can be seen from FIG. 2, the mass reduction rate in the alkaline environment decreases as the ratio of the coating resin to bone material amount increases.

[Examples 4 to 7] -Mortar production test-In each of Examples 4 to 7, mortar was prepared using the foamed glass lightweight aggregate of the present invention, and its evaluation test was conducted. First, by mixing the pre-coated foamed glass lightweight aggregate obtained in Example 1 with early-strength Portland cement, water, a superplasticizer, an antifoaming agent, and a separation reducing agent shown in the composition table of Table 3. Mortar was prepared. At this time, the water cement ratio (W /
C) is 40 to 48%, the mixing ratio of the lightweight aggregate (S) and cement (C) is S: C = 0.67 to 0.75: 1.0, and the water reducing agent (A
The d ₁₎ to mass ratio of the cement was changed between 0.3 to 1.0. In addition, an antifoaming agent (Ad ₂ ) and a separation reducing agent (Ad
₃ ) was added so that the cement mass ratio would be constant at 0.15% and 0.25%, respectively. In order to ensure the required fluidity when the water-cement ratio is changed, a high-performance water reducing agent (trade name: Rheobuild SP8S, manufactured by Pozoris Bussan Co., Ltd.) in a ratio of 0.3 to 1.
0% was added. The final blending ratios of Examples 4 to 7 are shown in Table 4.
Are shown together. The volume ratio Sv of 1 m ³ of the surface-treated lightweight aggregate was 50% or more.

[0042]

[Table 3]

[0043]

[Table 4]

In order to confirm the properties of the obtained mortar, measurement tests of flow, inseparability in water, air amount, unit volume mass, and compressive strength were carried out. The flow measurement test was based on JIS R 5201 (cement strength test). In Example 6, in order to confirm a change in fluidity (flow loss) with time, a flow test was performed after kneading the lightweight mortar and leaving it for 30 minutes and 60 minutes. Confirmation of the separability in water was made by visually dropping a mortar sample in a transparent container having a predetermined volume. A sample with good non-separability was marked with ◯, and a sample with poor separation was marked with x. The air amount measurement test and the unit volume mass measurement test conformed to JIS A 1116 (a test method (weight method) based on the weight of the unit volume mass and the air amount of concrete that is not yet solidified (weight method).
S A 1115 (method for sampling concrete that has not yet solidified), JIS A 1132 (how to prepare a specimen for concrete strength test), and JIS A 110
8 (compressive strength test method for concrete).

Table 5 shows the measurement test results of the mortar of the present invention. The lightweight mortars with the water-cement ratio set to 40 to 48% all showed good fluidity. The result of the flow test was about 150 mm. Almost no change in fluidity was confirmed as shown in the graph of FIG. Regarding the inseparability in water, even when dropped into water, cement particles and the like were not washed out, and sufficient inseparability in water was secured.

[0046]

[Table 5]

FIG. 4 is a graph showing changes in the unit volume mass and the 28-day-old compressive strength with respect to the water cement ratio. The unit volume mass of the lightweight mortar of the present invention is 1.
It was in the range of 1 to 1.2 t / m ³ . This is because even if the material is injected into the void behind the tunnel, the material does not flow down naturally,
Moreover, no harmful pressure is applied to the lining concrete. Regarding the property of strength development of the mortar of the present invention (compressive strength of 28 days old), it is always 20 N / m.
A strength of m ² or more was obtained, and 10 times or more high strength was secured as compared with the conventional lightweight void filling material, lightweight embankment, and interstitial filling material.

A characteristic of the filling property of the mortar in the gap of the present invention is that no material is filled in the gap below the set gap. This enables rational material design at the design stage. Therefore, the test of the gap passing property was confirmed using the test apparatus shown in FIG. This test equipment
It is possible to change the flow-down angle (inclination angle) of the material assuming the application location, and the inclination angle that can be set is within the range of 30 ° at maximum.

As a result of testing the light-transmitting mortar of the present invention with respect to the gap passing property using this test apparatus, the material completely stopped flowing at a gap of about 2 cm and a width of 20 cm at an inclination angle of 20 °.

[Example 8] -Example of use of a lightweight mortar as a cross-section restoration material by a spraying method-The pre-coated foamed glass lightweight aggregate obtained in Example 1 was used as an ordinary Portland cement. Mortar was prepared by mixing it with water, water, a water reducing agent, and a polymer emulsion for cement admixture, and various evaluation tests were carried out by spraying. At this time, as a mixing condition of the mortar, the water cement ratio (W / C) is 33%, the mixing ratio of the lightweight aggregate (S) and the cement (C) is 0.5: 1.0, and the water reducing agent (A
The d ₁₎ to mass ratio of the cement was 0.8%. In addition, the mass ratio of the quick-setting admixture (Ad ₂ ) mixed with the nozzle to the cement is 1
It was set to 5.0%. The recipe is shown in Table 7. The volume Sv of 1 m ^{3 of the} surface-treated lightweight aggregate was 50% or more.
P / C in the table is the mixing ratio of the cement (C) and the polymer emulsion for cement admixture (P).

[0051]

[Table 6]

[0052]

[Table 7]

The following items were tested to confirm the physical properties of the sprayed mortar. The flow test is JIS R 52
01 (cement strength test). The unit volume mass test is based on JIS A 1161 (a test method based on the unit volume mass of concrete that has not yet solidified and the weight of air content
(Weight method)). Specimens for the compressive strength test and length change rate test were basically prepared in accordance with JSCE F-561 (How to make specimens for compressive strength of shotcrete). The compressive strength test is based on JIS A for a cylindrical core test body with a diameter of 75 mm and a height of 150 mm.
1108 (compressive strength test method for concrete). The rate of change in length was measured according to JIS A 1129 (method for testing rate of change in length of mortar and concrete). Further, as an adhesive strength test, this lightweight mortar was sprayed on a dried flat plate of 30 cm × 30 cm × 6 cm, and the adhesive strength test was carried out by the method shown in FIG. 6 at the age of 28 days. Specifically, an upper tension jig was bonded to the surface of the mortar, a cut was made in the mortar along the side surface of the jig to reach the substrate, and the upper tension jig was pulled up perpendicular to the mortar surface. Then, the tensile load when the mortar peeled from the substrate was measured.

Table 8 shows the evaluation test results when the mortar of the present invention was sprayed. As a result, the mortar of the present invention was satisfactory as a lightweight mortar that can be applied by the spraying method. Further, the mortar having a flow of 220 mm had good pumpability and good finish.

[0055]

[Table 8]

[Example 9] -Example of use of light mortar as cross-section restoration material by plastering method-The same procedure as in Example 1 except that glass having a particle size of 1.2 mm was used and the density after treatment was A foam glass lightweight aggregate pre-coated with an acrylic emulsion to 0.78 g / cm ³ is a fast-setting cement, water, silica sand, water reducing agent, or re-emulsifiable powder resin cement shown in the composition table of Table 9. Mortars were prepared by mixing with the admixture polymer, shrinkage-reducing agent, defoaming agent, and fibers, and after making a test body by the plastering method, various evaluation tests were carried out. At this time, the water-cement ratio (W / C) is 38% as the mixing condition of the mortar,
The mixing ratio of the lightweight aggregate (S) and silica sand (SS) was 0.6: 0.
4, the mass ratio of water reducing agent (Ad ₁ ) to cement is 0.3%, the mass ratio of shrinkage reducing agent (Ad ₂ ) to cement is 3.0%, the mass ratio of defoaming agent (Ad ₃ ) to cement is It was set to 0.5%. The fiber mixing rate was 0.3% in terms of volume ratio of mortar. The recipe is shown in Table 10. Surface-treated lightweight aggregate 1
The volume Sv shown in m ³ was about 27%. P2 / B in Table 10 is cement (C + V) and re-emulsifiable powder resin (P2)
Is a mixing ratio with.

[0057]

[Table 9]

[0058]

[Table 10]

In order to confirm the physical properties of the sprayed mortar, the flow, the unit volume mass, the compressive strength and the rate of change in length were measured in the same procedure as in Example 8. Table 11 shows the evaluation test results when plastering the mortar of the present invention. The finish of the mortar of the present invention in which a flow of 131 mm was obtained was good.

[0060]

[Table 11]

[0061]

According to the present invention, it is possible to obtain a lightweight aggregate for mortar which is lightweight and has high strength, and is also excellent in chemical resistance, water permeability and the like. If waste glass is used as a raw material for foamed glass, the manufacturing cost can be reduced, and it can be a solution to environmental problems.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the resin coating rate and the water absorption rate of the foamed glass lightweight aggregate of the present invention.

FIG. 2 is a graph showing the alkali resistance of the foamed glass lightweight aggregate of the present invention.

FIG. 3 is a graph showing changes with time in flow test values of the mortar of the present invention.

FIG. 4 is a graph showing changes in unit volume mass and 28-day compressive strength with respect to water cement ratio.

FIG. 5 is a schematic view of a fluidity test device.

FIG. 6 is a schematic view of a spray mortar adhesion strength measuring device.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masanori Ito             Tokyu, 1-16-14 Shibuya, Shibuya-ku, Tokyo             Inside the corporation (72) Inventor Kenji Hayakawa             Tokyu, 1-16-14 Shibuya, Shibuya-ku, Tokyo             Inside the corporation (72) Inventor, Nagateru             7-6, Nihonbashi Odenmacho, Chuo-ku, Tokyo

Claims (8)

[Claims] 1. A lightweight aggregate for mortar, which is obtained by coating foamed glass with an organic polymer. 2. The lightweight aggregate for mortar according to claim 1, wherein the foam glass is foamed from waste glass. 3. The organic polymer is acrylic resin, epoxy resin, vinyl chloride resin, polyester resin, MMA.
The lightweight aggregate for mortar according to claim 1 or 2, which is at least one selected from the group consisting of resin and synthetic rubber. 4. The lightweight aggregate for mortar according to any one of claims 1 to 3, wherein the organic polymer is in the form of a polymer emulsion. 5. The lightweight aggregate for mortar according to claim 4, wherein the organic polymer is in the form of a mixture of an organic polymer and a hydraulic inorganic material. 6. A method for producing a lightweight aggregate for mortar, which comprises coating a glass foam with an emulsion or solution of an organic polymer, removing excess emulsion or solution, and then optionally drying. 7. The method for producing a lightweight aggregate for mortar according to claim 6, wherein the coating is performed at a mortar construction site. 8. A mortar containing a hydraulic inorganic material and the lightweight aggregate according to any one of claims 1 to 5.