JP5831133B2 - Cement composition, mortar composition, and cured mortar - Google Patents

Description

  The present invention relates to a cement composition, a mortar composition, and a mortar hardened body used for various construction works in the civil engineering and construction fields.

  Concrete used for various structures is inherently excellent in durability, but part of it may deteriorate depending on the structure and use environment. Such deterioration causes a decrease in the strength of the concrete and needs to be repaired. In repairing, after removing the deteriorated portion, a cross-sectional repair material such as a mortar composition is used.

  Patent Documents 1 to 4 are known as mortar compositions that are lightweight and have high strength and are used for cross-sectional restoration in the field of civil engineering and construction, and cement compositions used in the manufacture of mortar compositions. Patent Document 1 includes a cement and a glass aggregate produced by mixing a foaming agent with glass powder, granulating and firing as a mortar composition that is lightweight and has a certain level of strength and adhesive strength. A mortar composition is disclosed. In this patent document 1, the compression strength is improved by using silica fume as a part of the binder, the strength and adhesion can be improved by adding a polymer binder, and the waste glass is made of glass aggregate. It is disclosed that it can be recycled by making it a raw material.

Patent Document 2 contains a ceramic-based fired fine aggregate and silica fume, and is a lightweight mortar particularly having a specific gravity of 1.6 or less and a compressive strength of 50 N / mm ² or more as a lightweight mortar for spraying construction. Is disclosed.

  Patent Document 3 uses a lightweight aggregate for mortar in which foamed glass is coated with an organic polymer and a lightweight aggregate for mortar as a lightweight aggregate for mortar having excellent strength and alkali resistance and water permeability. A mortar composition was disclosed. In Patent Document 4, when the mortar composition is applied to the repaired part by blemish, the surface of the coating film is not conspicuous, rich in smoothness, excellent in appearance, and workability when applied with a hammer. In addition, a cement composition containing a granulated glass powder aggregate and dredged sand (natural sand) is disclosed as an excellent cement composition.

JP 2000-233961 JP 2001-039782 A JP 2003-089558 A JP 2004-256368 A

  However, the mortar composition using the lightweight aggregate of granulation type has good workability and, when integrated with the concrete structure, it was possible to obtain an appropriate compressive strength. Adhesiveness, especially adhesion durability was not sufficient.

  The present invention has good workability, and has a suitable compressive strength when integrated with a concrete structure, and can form a mortar cured body having excellent adhesion and adhesion durability. An object is to provide a cement composition and a mortar composition. Moreover, it aims at providing the mortar hardened | cured material which has moderate compressive strength, and has the outstanding adhesiveness and adhesion durability.

  In order to achieve the above object, in the present invention, a cement composition comprising Portland cement, limestone powder, inorganic expansion material, fine aggregate, lightweight aggregate and re-emulsified resin powder, The re-emulsified resin powder contains a styrene / acrylic copolymer resin as a main component and has a glass transition temperature (Tg) of −10 to 22 and is obtained by firing a raw material containing glass as a component. A cement composition that is at 0C is provided.

  By using the cement composition of the present invention as a cement composition for repair, it has good workability and has an appropriate compressive strength when integrated with a concrete structure (that is, a compressive strength equal to or higher than that of a concrete structure). ) And a cured mortar body having excellent adhesion and adhesion durability. As described above, the reason why the cured mortar obtained using the cement composition of the present invention has both excellent adhesiveness and adhesive durability is not necessarily clear. Each component contained in the product interacts with each other, and the action caused by the combination of the specific lightweight aggregate and the specific re-emulsified resin powder is considered to contribute to the improvement of adhesion and adhesion durability. ing.

  Another reason may be that the behavior at the adhesive interface with respect to fluctuations in outside air temperature is improved. That is, the mortar composition usually tends to generate fine cracks due to fluctuations in the outside air temperature (for example, when one year has passed outdoors), and the adhesiveness tends to decrease. However, according to the mortar composition of the present invention, by including the styrene / acrylic copolymer-based re-emulsified resin powder having a glass transition temperature of −10 to 22 ° C., in an environment where the temperature varies between low temperature and high temperature. It is considered that a mortar cured body having excellent adhesion and adhesion durability can be formed even when used.

  The cement composition of the present invention preferably has the following aspect. The cement composition of the present invention more preferably combines the following aspects as appropriate.

  The lightweight aggregate has a bulk specific gravity of 0.25 to 0.60, a particle size of 1200 μm or more and a mass ratio of particles of less than 2500 μm of 45% by mass or less, a particle size of 600 μm or more and It is preferable that the mass ratio of the particle | grains which are less than 1200 micrometers is 40-70 mass%. Thereby, it can be set as the cement composition which has the further outstanding construction property.

  5 to 80 parts by weight of limestone powder, 5 to 15 parts by weight of an inorganic expansive material, 5 to 90 parts by weight of fine aggregate, 3.5 to 30 parts by weight of lightweight aggregate, relative to 100 parts by weight of Portland cement And 3 to 15 parts by mass of the re-emulsified resin powder. This makes it possible to form a mortar cured body having better compressive strength and better adhesion durability.

  The inorganic expansion material preferably contains quick lime-gypsum expansion material. This makes it possible to form a mortar cured body having better compressive strength and better adhesion durability.

  The present invention also provides a mortar composition containing the cement composition and water, and a mortar cured body obtained by curing the mortar composition. Since this mortar composition includes the cement composition having the above-mentioned characteristics, it has excellent workability and forms a cured mortar body having appropriate compressive strength, excellent adhesiveness and adhesive durability. Can do. For this reason, it can be suitably used as a mortar composition for repair. Moreover, since the said mortar hardened | cured material is obtained using this mortar composition, it has the compressive strength equivalent to or more than concrete when integrated with concrete, and also has excellent adhesiveness and excellent adhesion durability. Combined with sex. Therefore, it is suitable as a restoration material for deteriorated concrete.

  According to the present invention, it is possible to form a mortar cured body having good workability, having a suitable compressive strength when integrated with a concrete structure, and having excellent adhesion and adhesion durability. Possible cement and mortar compositions can be provided. Moreover, according to this invention, the lightweight mortar hardening body which has moderate compressive strength, the outstanding adhesiveness, and the outstanding adhesion durability can be provided. The cement composition and the mortar composition of the present invention are suitably used for repairing a cross section of a concrete structure as a repair cement composition or a repair mortar composition. Moreover, if the cement composition or mortar composition of the present invention is used, it is possible to easily carry out the glazing or spraying.

<Cement composition>
Hereinafter, preferred embodiments of the cement composition of the present invention will be described below. The cement composition of the present embodiment is a repair cement composition used for repairing concrete. The cement composition of the present embodiment is a repair cement composition including Portland cement, limestone powder, inorganic expansion material, fine aggregate, lightweight aggregate, and re-emulsified resin powder.

  The lightweight aggregate contained in the cement composition is a lightweight aggregate (glass-fired lightweight aggregate) obtained by firing a raw material containing glass as a main component. The re-emulsifying resin powder contained in the cement composition contains a styrene / acrylic copolymer resin as a main component and has a glass transition temperature of (Tg) −10 to 22 ° C. The mortar composition for repair obtained by blending and kneading the repair cement composition of the present embodiment and water has good workability. Moreover, if this repair mortar composition is used, a cured mortar cured body having an appropriate compressive strength when combined with a concrete structure and having both excellent adhesiveness and excellent adhesion durability can be obtained. Can do. Hereinafter, each component contained in the cement composition of this embodiment is demonstrated in detail.

  As the Portland cement, it is preferable to use at least one selected from ordinary Portland cement, early-strength Portland cement, ultra-early strong Portland cement, moderately hot Portland cement, sulfate-resistant Portland cement, low heat Portland cement, and white Portland cement.

  As the limestone powder, a normal commercially available product can be used. Among these, it is preferable to use limestone powder (cold stone powder) with high whiteness.

  The limestone powder preferably does not contain particles having a particle size of 300 μm or more, based on the whole limestone powder, and has a particle size of 150 μm or more and a particle mass ratio of less than 300 μm of less than 20% by mass, The mass ratio of particles having a particle size of 75 μm or more and less than 150 μm is 10 to 50% by mass. By including the limestone powder having a particle diameter in the above-mentioned range, the cement composition of the present embodiment can sufficiently secure the time for constructing the repair mortar composition, and exhibits good strength. Can be obtained.

  The particle diameter of the limestone powder can be measured using several sieves having different nominal dimensions as defined in JIS Z 8801: 2006. Further, in this specification, “a mass ratio of particles having a particle diameter of 150 μm or more and less than 300 μm” means that when a sieve having a sieve size of 300 μm is used, the sieve passes through a sieve having a sieve size of 300 μm, and When a sieve having a mesh size of 150 μm is used, it means a mass ratio of particles remaining on the sieve having a mesh size of 150 μm to the entire limestone powder.

The content of limestone powder in the cement composition of the present embodiment is 100 parts by mass of Portland cement.
Preferably it is 5 to 80 parts by mass,
More preferably, it is 10-70 parts by mass,
More preferably, it is 15-60 mass parts,
Especially preferably, it is 20-58 mass parts.

  By containing the limestone powder in the above-described preferable range, it is possible to sufficiently secure the time for constructing the repairing mortar composition and to obtain good strength.

  As the inorganic expansion material, quick lime-gypsum expansion material, gypsum expansion material, calcium sulfoaluminate expansion material and the like can be used. Among these, it is preferable to include a quicklime-gypsum-based expansion material from the viewpoint of obtaining a mortar cured body having further excellent adhesion durability.

The content of the inorganic expansion material in the cement composition of the present embodiment is based on 100 parts by mass of Portland cement.
Preferably it is 5-15 parts by mass,
More preferably, it is 6 to 13 parts by mass,
More preferably, it is 7-12 mass parts,
Most preferably, it is 8-11 mass parts.

  By adjusting the content of the inorganic expansive material to the above range, more appropriate expansibility is expressed, and excessive shrinkage of the repaired mortar cured body can be suppressed. In addition, the generation of cracks due to excessive expansion can be sufficiently suppressed.

  The fine aggregate preferably has a mass ratio of particles having a particle diameter of 600 μm or more based on the whole fine aggregate as less than 5% by mass and a water absorption rate of 1.6% or less. As such fine aggregates, those selected from sands such as quartz sand, river sand, land sand, sea sand and crushed sand can be suitably used.

  The particle diameter of the fine aggregate can be measured by using several sieves having different nominal dimensions as defined in JIS Z 8801: 2006. Moreover, in this specification, "the mass ratio of the particle | grains whose particle diameter is 600 micrometers or more" means the mass ratio with respect to the whole fine aggregate of the particle | grains on a sieve residue when a sieve with a sieve mesh of 600 micrometers is used. Say. Further, the water absorption rate of the fine aggregate is a value measured according to the method of measuring the water absorption rate (unit:%) of the aggregate defined in JIS A 1109: 2006.

  When the fine aggregate contains coarse particles having a particle diameter of 600 μm or more in an amount of 5% by mass or more, or when the fine aggregate has a water absorption rate exceeding 1.6%, the cement composition of the present embodiment is sufficient. Excellent workability tends to be impaired. There is no restriction | limiting in particular in the lower limit of the said coarse grain part, and 0 mass% may be sufficient.

From the viewpoint of making a cement composition with even better workability, the coarse particles in the fine aggregate are
Preferably it is 0-3 mass%,
More preferably, it is 0 to 0.5% by mass,
More preferably, it is 0-0.2 mass%,
Most preferably, it is 0.01-0.15 mass%.

There is no restriction | limiting in particular in the lower limit of a water absorption rate, and 0% may be sufficient. From the viewpoint of making a cement composition with better workability, the water absorption rate of fine aggregate is
Preferably 0 to 1.50%,
More preferably 0 to 1.40%,
More preferably, it is 0-1.30%,
Especially preferably, it is 0.1 to 1.28%.

  The unit volume mass of the fine aggregate is preferably 1.45 to 1.70 kg / L. Thereby, it can be set as the cement composition which has the further outstanding construction property. Here, the “unit volume mass” refers to the unit volume mass (unit: kg / L) of the aggregate defined in JIS A 1104-2006.

From the viewpoint of making the cement composition with better workability, the unit volume mass of the fine aggregate is
Preferably it is 1.45 to 1.70 kg / L,
More preferably, it is 1.50-1.60 kg / L,
More preferably, it is 1.51-1.57 kg / L,
Particularly preferred is 1.52 to 1.55 kg / L.

The content of fine aggregate in the cement composition of the present embodiment is 100 parts by mass of Portland cement,
Preferably it is 5-90 parts by mass,
More preferably, it is 10-70 parts by mass,
More preferably, it is 15-55 mass parts,
Especially preferably, it is 30-40 mass parts.

  By making the content of fine aggregate in the cement composition within the above range, it has better workability and has a compressive strength equal to or higher than that of the concrete structure when integrated with the concrete structure. On the other hand, it is possible to obtain a cured mortar cured body having further excellent adhesion durability.

  The lightweight aggregate is a glass aggregate obtained by a production method having a firing step of firing a raw material mainly composed of glass (for example, a glass content of 80% by mass or more). As glass contained in the raw material, waste glass such as bottles and plate glass can be used. Further, since the glass aggregate is lightweight and is a spherical substance containing glass as a main component, it has a high strength and a small amount of water absorption. Therefore, further weight reduction can be achieved while ensuring the strength of the mortar cured body.

  The lightweight aggregate (glass aggregate) manufacturing method includes, for example, a blending process in which a raw material containing waste glass as a main component is pulverized by a pulverizer such as a ball mill, and the blended raw material is granulated by a spray dryer. A spheroidizing step for obtaining a granular product by spheronization, a baking step for baking the granular material with a rotary kiln or the like, and a classification step for classifying with a vibration sieve.

The bulk specific gravity of lightweight aggregate is
Preferably it is 0.25 to 0.60,
More preferably, it is 0.30 to 0.55,
More preferably, it is 0.33-0.50,
Especially preferably, it is 0.35-0.45.

  By setting the bulk specific gravity of the lightweight aggregate within the above range, the workability can be further improved.

The lightweight aggregate does not contain particles having a particle diameter of 2500 μm or more, and the mass ratio of particles having a particle diameter of 1200 μm or more and less than 2500 μm with respect to the entire lightweight aggregate is:
Preferably it is 45 mass% or less,
More preferably, it is 1-40 mass%,
More preferably, it is 2-37 mass%.

In addition, while satisfying the above-described mass ratio, the mass ratio of the particles having a particle diameter of 600 μm or more and less than 1200 μm with respect to the entire lightweight aggregate,
Preferably it is 40-70 mass%,
More preferably, it is 45-65 mass%,
More preferably, it is 50-60 mass%.

  By setting the particle size of the lightweight aggregate within the above-mentioned mass ratio range, a mortar cured body having better adhesion and adhesion durability can be obtained while having better workability.

  The particle diameter of the lightweight aggregate can be measured by using several sieves having different nominal dimensions as defined in JIS Z 8801: 2006. Further, in this specification, “the mass ratio of particles having a particle diameter of 1200 μm or more and less than 2500 μm” means that when a sieve having a sieve mesh of 2500 μm is used, the sieve passes through a sieve having a sieve mesh of 2500 μm and has a sieve mesh of 1200 μm. When a sieve is used, it means the mass ratio of particles remaining on a sieve having a sieve mesh of 1200 μm to the entire lightweight aggregate.

The content of lightweight aggregate is 100 parts by mass of Portland cement.
Preferably 10 to 70 parts by volume,
More preferably 15 to 60 parts by volume,
More preferably, it is 20-55 volume parts,
Particularly preferred is 30 to 50 parts by volume.

Since the lightweight aggregate normally defines the blending amount on the basis of volume, the range of the content is indicated by “capacity part”, but the following content is preferable on the mass basis. That is, the lightweight aggregate content is 100 parts by mass of Portland cement.
Preferably it is 3.5 to 30 parts by mass,
More preferably, it is 5 to 25 parts by mass,
More preferably, it is 7-22 mass parts,
Especially preferably, it is 9-20 mass parts.

  By setting the content of the lightweight aggregate in the above range, it is possible to obtain a hardened mortar having excellent workability and further excellent adhesion and adhesion durability.

  As the re-emulsifying resin powder, one produced by a known production method can be used. For example, it is preferable to use a re-emulsified resin powder obtained by spraying an aqueous polymer dispersion or removing the solvent by a method such as freeze drying and drying. The re-emulsified resin powder may have an anti-blocking agent attached to the surface of the re-emulsified resin powder.

  The re-emulsifying resin powder includes a styrene / acrylic copolymer resin as a main component, and contains 50% by mass or more of styrene and at least one alkyl (meth) acrylate in total, based on the total monomer. And what contains 0.1-50 mass% of the copolymer based on an epoxide group containing ethylenically unsaturated comonomer is preferable on the basis of total monomers. More preferably, the comonomer unit of the copolymer includes a reactive epoxide group. As a result, a mortar cured body having even better adhesion durability can be obtained.

The glass transition temperature (Tg) of the re-emulsified resin powder is
-10 to 22 ° C,
Preferably 0-21 ° C
More preferably 5-20 ° C
More preferably, it is 10-20 degreeC.

  When the glass transition temperature (Tg) of the re-emulsified resin powder is in the above-mentioned range, a mortar cured body having further excellent adhesion durability can be obtained. In addition, the glass transition temperature in this specification can be measured by DSC method. Specifically, first, the test piece is heated from room temperature at a rate of 3 ° C./min, and the endothermic amount is measured with a differential scanning calorimeter to obtain an endothermic curve. Next, the glass transition temperature (Tg) can be determined from the intersection of the base line of the obtained endothermic curve and the tangent at the inflection point (the point at which the upwardly convex curve changes to the downwardly convex curve).

The content of the re-emulsified resin powder is 100 parts by mass of Portland cement.
Preferably it is 3-15 parts by mass,
More preferably 4 to 12 parts by mass,
More preferably 5 to 10 parts by mass,
Especially preferably, it is 6-9 mass parts.

  By making the addition amount of the re-emulsifying resin powder within the above range, it is possible to further improve the adhesiveness and adhesion durability between the mortar cured body and the concrete structure.

  The cement composition of the present embodiment preferably includes synthetic resin fibers from the viewpoint of improving the bending strength of the mortar cured body and obtaining a mortar cured body having a good surface in which generation of cracks is sufficiently suppressed. .

  As the synthetic resin fibers, synthetic resin fibers made of synthetic resin components such as polyethylene, ethylene / vinyl acetate copolymer (EVA), polyolefin such as polypropylene, polyester, polyamide, polyvinyl alcohol, and polyvinyl chloride can be used. One kind selected from these can be used alone or in combination of two or more kinds.

The fiber length of the synthetic resin fiber is preferably 2.0 to 15 mm from the viewpoint of handling properties when mixed with the cement composition and dispersibility in the mortar composition for repair,
More preferably, it is 3.0-10 mm,
More preferably, it is 4.0-8.0 mm.
Especially preferably, it is 5.0-7.0 mm.

Synthetic resin fibers can be added as long as the properties of the cement composition are not impaired. The amount of synthetic resin fiber added is 100 parts by weight of Portland cement.
Preferably it is 0.01-5 parts by mass,
More preferably 0.05 to 2 parts by mass,
More preferably 0.08 to 1 part by mass,
Especially preferably, it is 0.3-0.5 mass part.

  By setting the fiber length and addition amount of the synthetic resin fiber within the above-described ranges, a mortar cured body having a surface in which generation of cracks is sufficiently suppressed can be obtained.

  The cement composition of this embodiment can be suitably used for cross-sectional repair of a concrete structure. By using the cement composition of the present embodiment, a lightweight mortar composition for repair that can be easily applied with a bat or sprayed can be obtained.

<Mortar composition>
The mortar composition of this invention can be prepared by mix | blending and knead | mixing the above-mentioned cement composition and water. Preferred embodiments of the mortar composition of the present invention are described below. The mortar composition of this embodiment can be suitably used as a mortar composition for repair. When preparing a mortar composition, the flow value and unit volume mass of a mortar composition can be adjusted by changing the compounding quantity of water suitably. Thus, the mortar composition for repair suitable for a use can be prepared by changing the compounding quantity of water. Here, the flow value is a value measured in accordance with a test method described in JIS R 5201-1997 “Cement physical test method”, and the unit volume mass is JIS A 1171-2000 “polymer cement”. It is a value (unit: kg / L) measured based on the test method described in “Testing method of mortar”.

The amount of water blended is 100 parts by weight of the cement composition.
Preferably 12 to 27 parts by mass,
More preferably, it is 14 to 25 parts by mass,
More preferably, it is 16-24 mass parts,
Most preferably, it is 18-23 mass parts.

The flow value of the mortar composition of this embodiment is
Preferably it is 155 to 210 mm,
More preferably, it is 160-200 mm,
More preferably, it is 165 to 190 mm,
Especially preferably, it is 170-180 mm.

  By making a flow value into the above-mentioned range, it can be set as the mortar composition which has much more favorable workability (good wiping property and spraying property).

The unit volume mass of the mortar composition of this embodiment is
Preferably it is 1.45-1.85 kg / L,
More preferably, it is 1.50-1.80 kg / L,
More preferably, it is 1.55-1.78 kg / L,
Particularly preferred is 1.50 to 1.76 kg / L (liter).

  By setting the unit volume mass within the above range, while maintaining good workability of the mortar composition (good coatability and sprayability), moderate compressive strength and further integration with the concrete structure A mortar cured body having excellent adhesiveness can be obtained.

<Hard mortar>
The mortar cured body of the present invention can be obtained by curing the mortar composition described above. A preferred embodiment of the mortar cured body of the present invention will be described below. The mortar cured body of this embodiment can be suitably used as a mortar cured body for repair. That is, the mortar cured body of the present embodiment formed by curing the above mortar composition has a compressive strength equal to or higher than that of concrete when integrated with a concrete structure, and has excellent adhesiveness and excellent Combines adhesive durability.

  Here, the compressive strength is a value measured according to a test method described in JIS R 5201-1997 “Cement physical test method”. Moreover, adhesive strength (standard time) is a value measured based on the adhesion strength test method (standard curing) as described in JIS A 6916-2000 “Preparation Coating Material for Architecture”. Adhesive strength (after wet / hot / cold test, after alkali resistance test) is standard for East Japan / Central Japan / West Japan Expressway Co., Ltd. “Structure Construction Management Guidelines July 2009 3-5-5 Performance check It is a value measured according to the adhesion test method with concrete described in “Table 3-5-2 Performance check items for cross-sectional restoration by plastering method”.

The compressive strength of the mortar cured body of this embodiment is
Preferably it is 30 N / mm ² or more,
More preferably, it is 32 N / mm ² or more,
More preferably, it is 34 N / mm ² or more,
Particularly preferably, it is 36 N / mm ² or more.

  When the compressive strength is in the above-described range, the cured mortar body has strength suitable for integration, that is, strength equal to or higher than that of concrete when integrated with the concrete structure.

The adhesive strength (standard time) of the mortar cured body of this embodiment is
Preferably it is 1.5 N / mm ² or more,
More preferably, it is 2.0 N / mm ² or more,
More preferably, it is 2.3 N / mm ² or more,
Particularly preferably, it is ^2.5 N / mm ² or more.

The adhesive strength (when wet) of the mortar cured body of this embodiment is
Preferably it is 1.5 N / mm ² or more,
More preferably, it is 2.0 N / mm ² or more,
More preferably, it is 2.3 N / mm ² or more,
Particularly preferably, it is ^2.5 N / mm ² or more.

  When the adhesive strength (standard time, when wet) is equal to or higher than the above value, the repaired mortar cured body has sufficiently excellent adhesiveness when integrated with the concrete structure.

The adhesive strength of the mortar cured body of the present embodiment (after the hot and cold repeated test) is
Preferably it is 1.5 N / mm ² or more,
More preferably, it is 1.7 N / mm ² or more,
More preferably, it is 1.9 N / mm ² or more,
Particularly preferably, it is 2.0 N / mm ² or more.

The adhesive strength (after the alkali resistance test) of the mortar cured body of this embodiment is
Preferably it is 1.5 N / mm ² or more,
More preferably, it is 1.7 N / mm ² or more,
More preferably, it is 1.9 N / mm ² or more,
Particularly preferably, it is 2.0 N / mm ² or more.

  When the adhesive strength (after the hot and cold repeated test and after the alkali resistance test) is equal to or higher than the above value, the mortar cured body is excellent in adhesion durability after being integrated with the concrete structure.

  The mortar cured body of the present embodiment can be evaluated for durability by an accelerated neutralization test. The accelerated neutralization test of the mortar cured body can measure the neutralization depth in accordance with the test method described in JIS A 1153-2003 “Accelerated neutralization test of concrete”.

The neutralization depth (average value) of the mortar cured body of this embodiment is:
In the case of the age of 28 days, it is preferably 1.0 mm or less,
In the case of 56 days of age, it is preferably 1.0 mm or less,
In the case of the age of 91 days, it is preferably 2.0 mm or less,
In the case of an age of 182 days, it is preferably 3.0 mm or less.

  The mortar cured body of this embodiment can be evaluated for frost damage resistance by a freeze-thaw test. The freeze-thaw test of the mortar hardened body is based on the test method described in JIS A 1148-2010 “Method of freeze-thawing concrete (Method A)”, and the primary resonance frequency and mass of the flexural vibration are measured, and the relative motion is measured. Elastic modulus and mass reduction rate can be calculated.

The relative dynamic elastic modulus of the cured mortar body of this embodiment is
In the case of about 60 cycles, it is preferably 96% or more,
In the case of about 150 cycles, it is preferably 95% or more,
In the case of about 210 cycles, it is preferably 93% or more,
In the case of about 300 cycles, it is preferably 90% or more.

The mass reduction rate of the mortar cured body of this embodiment is
In the case of about 60 cycles, it is preferably 0.1% or less,
In the case of about 150 cycles, it is preferably 0.2% or less,
In the case of about 210 cycles, it is preferably 0.3% or less,
In the case of about 300 cycles, it is preferably 0.5% or less.

  The cement composition of the present embodiment has an appropriate compressive strength when it is integrated with good workability and a concrete structure, and has excellent adhesiveness and excellent adhesion durability.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment.

  Hereinafter, the contents of the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to the following examples.

(Examples 1-5, Comparative Examples 1-9)
[Preparation of cement composition for repair]
The raw materials shown in (1) to (7) below were prepared.
(1) Portland cement Normal Portland cement (manufactured by Ube Mitsubishi Cement Co., Ltd., Blaine specific surface area = 3300 cm ² / g)
(2) Limestone powder Cryosite powder (mass ratio of particles having a particle diameter of 150 μm or more and less than 300 μm = 15.2 mass%, mass ratio of particles having a particle diameter of 75 μm or more and less than 150 μm = 35.6% by mass)
(3) Inorganic expansive material ・ Quicklime-gypsum expansive material (manufactured by Taiheiyo Material Co., Ltd.)
(4) Fine aggregate ・ Silica sand (mass ratio of particles having a particle diameter of 600 μm or more = 0.1 mass%, water absorption rate = 1.25%, unit volume mass = 1.53 kg / L)

(5) Lightweight aggregate-Lightweight aggregate A: Glass aggregate obtained by firing a raw material containing glass as a main component (bulk specific gravity = 0.35, particles having a particle diameter of 1200 μm or more and less than 2000 μm) Mass ratio = 36.7 mass%, particle diameter of 600 μm or more and mass ratio of particles less than 1200 μm = 54.4 mass%)
Lightweight aggregate B: Glass aggregate obtained by firing a raw material containing glass as a main component (bulk specific gravity = 0.40, mass ratio of particles having a particle diameter of 1200 μm or more and less than 2000 μm = 36. 7% by mass, mass ratio of particles having a particle diameter of 600 μm or more and less than 1200 μm = 60.2% by mass)
Lightweight aggregate C: pearlite (bulk specific gravity = 0.19, particle diameter of 1200 μm or more and less than 2000 μm, mass ratio of particles = 79.9% by mass, particle diameter of 600 μm or more and less than 1200 μm) Particle mass ratio = 10.5 mass%)

(6) Re-emulsified resin powder-Resin powder A: Styrene / acrylic copolymer re-emulsified resin powder (glass transition temperature = 15 ° C)
Resin powder B: Styrene / acrylic copolymer re-emulsified resin powder (glass transition temperature = −15 ° C.)
Resin powder C: Styrene / acrylic copolymer re-emulsified resin powder (glass transition temperature = 23 ° C.)
Resin powder D: Acrylic re-emulsified resin powder (glass transition temperature = -3 ° C.)
Resin powder E: Vinyl acetate / veova / acrylic copolymer re-emulsified resin powder (glass transition temperature = 15 ° C.)
(7) Synthetic resin fiber
・ Vinylon fiber (manufactured by Kuraray Co., Ltd., fiber length = 6 mm)

  (1) Portland cement, (2) Limestone powder, (3) Inorganic expansive material, (4) Fine aggregate, (5) Lightweight aggregate, (6) Re-emulsified resin powder, (7) Synthetic resin Fibers were blended at the ratios shown in Tables 1 and 2, and repair cement compositions for each Example and each Comparative Example were prepared. In Tables 1 and 2, the mixing ratio of (2) limestone powder, (3) inorganic expansion material, (4) fine aggregate, (6) re-emulsified resin powder is (1) mass relative to 100 parts by mass of Portland cement. (5) The blending ratio of the lightweight aggregate is shown in (1) capacity part with respect to 100 parts by mass of Portland cement. In addition, if the blending ratio (capacity part) of the lightweight aggregate shown in Tables 1 and 2 is multiplied by the bulk specific gravity of each lightweight aggregate, the blending ratio of the lightweight aggregate to 100 parts by mass of Portland cement (mass part) ) Can be calculated. Blanks in Tables 1 and 2 indicate unmixed.

[Preparation of mortar composition for repair]
For each 1 kg of the cement composition for repair prepared at the blending ratio shown in Table 1 and Table 2, the amounts of water shown in Table 3 and Table 4 are blended and kneaded, and the mortar composition for repair in each example and each comparative example A product was prepared. The kneading was performed at a low speed for 3 minutes using a Hobart mixer under the conditions of a temperature of 20 ° C. and a relative humidity of 65%.

[Method for evaluating physical properties of mortar composition for repair and cured mortar]
The flow value, unit volume mass, compressive strength, and adhesive strength of the repaired mortar compositions or cured mortar compositions of each Example and each Comparative Example were measured. The measurement results were as shown in Table 3 and Table 4. Each measurement was performed by the method shown below.

(1) Measurement method of flow value The flow value was measured based on the test method described in JIS R 5201-1997 "Cement physical test method".
(2) Measuring method of unit volume mass Unit volume mass was measured based on the test method as described in JIS A1171-2000 "Test method of polymer cement mortar".
(3) Measuring method of compressive strength Based on the test method described in JIS R 5201-1997 "Physical test method of cement", compressive strength at the age of 28 days was measured.
(4) Measuring method of adhesive strength The adhesive strength was measured under different conditions as follows.
Standard time Adhesive strength at standard time was measured in accordance with the adhesion strength test method (standard curing) described in JIS A 6916-2000 “Preparation Coating Material for Building Construction”.
・ After wet, hot and cold repeated test, after alkali resistance test East Japan / Central Japan / West Japan Expressway Co., Ltd. Standard “Structure Construction Management Guidelines July 2009 Version 3-5-5 Cross Section Restoration Performance Check Table 3- In accordance with the adhesion test method with concrete described in “5-2 Performance Check Items for Cross-Section Restoration by Plastering Method”, the adhesive strength after wet, after the hot and cold repeated test and after the alkali resistance test was measured.

  The adhesive strength at the standard time and when wet was used as an index for evaluating the adhesiveness, and the adhesive strength after the repeated heating and cooling test and after the alkali resistance test was used as an index for evaluating the adhesive durability.

  As shown in Table 3 and Table 4, the mortar hardened bodies of Examples 1 to 5 had high adhesive strength in any environment. The flow values of the mortar compositions for repair in Examples 1 to 5 were 170 to 180 mm. This result has shown that the cement composition for repair of each Example has favorable workability | operativity (good wiping property and spraying property).

  The unit volume mass of the repair mortar compositions of Examples 1 to 5 was 1.50 to 1.80 kg / L. This result has shown that the cement composition for repair of each Example has favorable workability | operativity (good wiping property and spraying property).

The mortar hardened bodies of Comparative Examples 6, 8 and 9 using lightweight aggregate C (perlite) are resin powders having different glass transition temperatures (Tg), but all have low adhesive strength. . In particular, it was confirmed that the adhesive strength after the hot / cold repeated test and the alkali resistance test as an index of the adhesive durability was 0 N / mm ² , and the durability was inferior. In Comparative Example 8, the compressive strength was 30 N / mm ² or more, but since the adhesive strength was low, no correlation was found between the compressive strength value and the adhesive strength value.

From a comparison between Comparative Example 6 in which the resin powder B was blended and Comparative Examples 5 and 7 in which the resin powder B was blended and replaced with the lightweight aggregate C (perlite) to the lightweight aggregate A (glass-fired lightweight aggregate), When lightweight aggregate A was mix | blended, the tendency for adhesive strength to become high was confirmed. However, in Comparative Examples 5 and 7, some of the four types of adhesive strength were as low as 1.5 N / mm ² or less.

From a comparison between Comparative Example 1 in which the resin powder B was blended and Example 1 in which the resin powder A was blended, it was confirmed that the adhesive strength was increased by blending the resin powder A. In Example 1, all four types of adhesive strength is at 1.5 N / mm ² or more, compressive strength was 30 N / mm ² or more.

  From the comparison between Example 1 in which the resin powder A was blended and Comparative Examples 2 and 3 in which the resin powder D was blended, when the resin powder D was blended, regardless of the blending amount of the lightweight aggregate A, after the hot and cold repeated test It was confirmed that the adhesive strength of the sheet was lowered.

From the comparison between Examples 2 and 3 in which resin powder A was blended and Comparative Example 4 in which resin powder D was blended, four types of adhesive strength were obtained regardless of the blending amount of lightweight aggregate A by blending resin powder A. Was confirmed to be 1.5 N / mm ² or more.

In Example 4 and Example 5, lightweight aggregates A and B having different bulk specific gravities are blended, and both have four types of adhesive strengths of 1.5 N / mm ² or more, and a compressive strength of 30 N / mm ² or more.

  From the above, as in Examples 1 to 5, re-emulsified resin powder (resin powder A) having a glass transition temperature in the range of −10 to 22 ° C. and made of a styrene / acrylic copolymer resin and glass firing The repair cement composition containing lightweight aggregates (lightweight aggregates A and B) has good workability, and has an appropriate compressive strength when integrated with a concrete structure, and has excellent adhesiveness and It was confirmed to have excellent adhesion durability. That is, the repair cement composition of this example can be suitably used for cross-sectional repair of a concrete structure, and can easily perform operations such as glazing or spraying.

(Neutralization depth)
The mortar composition for repair in Example 5 was designated as Example 6, and 1: 3 mortar prepared with the formulation described in JIS A 5201-2002 “Physical Test Method for Cement” was designated as Comparative Example 10 and JIS A 1153-2003 “ The neutralization depth was measured according to the test method described in “Accelerated neutralization test of concrete”. Three specimens having a square cross-sectional shape with a side length of 100 mm and a length of 400 mm were prepared for use in the accelerated neutralization test.

  The specimen was demolded after one day of material age, cured in water until the age of 4 weeks, and then cured in air until the age of 8 weeks. Moreover, between 7 to 8 weeks of age, the driving surface, bottom surface, and both end surfaces of the specimen were sealed. Neutralization promotion conditions were 20 ° C., relative humidity 65%, and carbon dioxide concentration 5%. About the test piece in each age period, it cut | disconnected in the position of 60 mm from the edge part, sprayed the phenolphthalein 1% alcohol solution, and about the length (mm) of the part which does not turn red, it divided into 6 equally per side 5 The place was measured and the average value of the obtained values was calculated. Table 5 shows the measurement results (average values) of Example 6 and Comparative Example 10.

  As shown in Table 5, for Example 6, the average value of the neutralization depth is 0.0 mm until the material age of 91 days, and the average value is 2.0 mm even at the material age of 182 days, which is excellent in durability. Showed that. On the other hand, as for Comparative Example 10, the average value was 2.4 mm at the age of 28 days, indicating that the durability was not excellent.

(Freeze-thaw)
The mortar composition for repair of Example 5 was designated as Example 7, and 1: 3 mortar prepared with the formulation described in JIS A 5201-2002 “Physical Test Method for Cement” was designated as Comparative Example 11 and JIS A 1148-2010 “ Based on the test method described in “Method for Freezing and Thawing Concrete (Method A)”, the primary resonance frequency and mass of flexural vibration were measured, and the relative dynamic elastic modulus and mass reduction rate were calculated. Three specimens having a square cross-sectional shape with a side length of 100 mm and a length of 400 mm were prepared for the freeze-thaw test.

  The specimens were demolded after 1 day of age, and were cured in water at 20 ° C. until the age of 4 weeks. The test starting material age is 28 days, and in one cycle of freezing and thawing, the center temperature of the specimen decreases from 5 ° C. to −18 ° C. and increases from −18 ° C. to 5 ° C., and 3 to 4 hours. did. Measurement of the primary resonance frequency and mass of the flexural vibration was performed about every 30 cycles, and the average value of the obtained values was calculated. Table 6 shows the measurement results (average values) of Example 7 and Comparative Example 11.

  As shown in Table 6, Example 7 showed less fluctuation in relative kinematic elastic modulus and mass reduction rate than Comparative Example 11, indicating excellent frost damage resistance.

  According to the present invention, a lightweight mortar cured body having good workability and having a compressive strength suitable for integration and excellent adhesiveness and adhesion durability when integrating with a concrete structure. A cement composition and a mortar composition can be provided. Moreover, while having moderate compressive strength, the lightweight mortar hardening body which has the outstanding adhesiveness and the outstanding adhesion durability can be provided. The cement composition and the mortar composition of the present invention are suitably used for repairing a cross section of a concrete structure as a repair cement composition or a repair mortar composition. Moreover, if the cement composition and the mortar composition of the present invention are used, it is possible to easily carry out glazing or spraying.

Claims (6)

A cement composition comprising Portland cement, limestone powder, inorganic expansion material, fine aggregate, lightweight aggregate and re-emulsified resin powder,
For 100 parts by mass of Portland cement,
5 to 80 parts by mass of the limestone powder, 5 to 15 parts by mass of the inorganic expansion material, 5 to 90 parts by mass of the fine aggregate, 3.5 to 30 parts by mass of the lightweight aggregate, and the re-emulsification. 3 to 15 parts by mass of a resin powder,
The lightweight aggregate is obtained by firing a raw material containing waste glass as a main component,
The re-emulsified resin powder contains a styrene / acrylic copolymer resin as a main component, and has a glass transition temperature (Tg) of 5 to 20 ° C. The lightweight aggregate is
The bulk specific gravity is 0.25 to 0.60,
The mass ratio of particles having a particle diameter of 1200 μm or more and less than 2000 μm is 45% by mass or less,
The cement composition according to claim 1, wherein a mass ratio of particles having a particle diameter of 600 µm or more and less than 1200 µm is 40 to 70 mass%. The limestone powder is
The mass ratio of particles having a particle size of 150 μm or more and less than 300 μm is less than 20% by mass,
The cement composition according to claim 1 or 2, wherein a mass ratio of particles having a particle diameter of 75 µm or more and less than 150 µm is 10 to 50 mass%.   The cement composition according to any one of claims 1 to 3, wherein the inorganic expansion material includes a quicklime-gypsum expansion material.   A mortar composition comprising the cement composition according to any one of claims 1 to 4 and water. A mortar cured product obtained by curing the mortar composition according to claim 5.