JP6326992B2 - Acid-resistant hydraulic composition, mortar composition, and cured mortar - Google Patents

Description

  The present invention is an acid resistant material that can be suitably used for construction, repair, and repair of concrete structures such as civil engineering and building facilities under corrosive environments such as sewage treatment facilities, agricultural settlement drainage facilities, and hot spring drainage facilities. Water-soluble hydraulic composition and mortar composition. The present invention also relates to a mortar cured body.

  In sewage treatment facilities such as sewage treatment plants, sludge treatment plants, and sewage pipes, sulfate contained in the wastewater is decomposed by sulfate-reducing bacteria to generate hydrogen sulfide. The hydrogen sulfide is converted into sulfuric acid by sulfur-oxidizing bacteria that inhabit the inner wall surface of the concrete structure used in sewage treatment facilities. If sulfuric acid remains on the inner wall surface as it is, the inner wall surface of the concrete structure will continue to be exposed to the sulfuric acid acidic atmosphere, and concrete elution, that is, corrosion will occur. In addition, organic acids contained in the wastewater synergistically cause corrosion deterioration of concrete.

  As the corrosion of concrete structures progresses, it may lead to the leakage of sewage, as well as the collapse of the facilities themselves, so the suppression of corrosion of concrete structures is an important issue in cities where sewerage has developed. Yes. Under such circumstances, various materials having acid resistance performance including an alumina cement-based material as a main component have been proposed.

For example, in Patent Document 1, acid resistance is obtained by using a water retaining agent, a retarder, or the like in a mixture comprising 20 to 90% by weight of alumina cement and 10 to 80% by weight of slag powder having a specific surface area of 3000 to 15000 cm ² / g. There has been proposed a hydraulic composition with improved properties and brittleness on the surface of a cured body.

  Patent Document 2 proposes a mortar composition for corrosive environment facilities containing alumina cement and alumina cement clinker aggregate as essential components. Patent Document 3 proposes an acid-resistant cement composition having improved acid resistance and adhesiveness by containing alumina cement, alumina cement clinker aggregate, and steelmaking dust. In patent document 4, the cement composition which has an effect in prevention of the conversion of a calcium aluminate type compound and improves acid resistance by containing a calcium aluminate type compound and a blast furnace fume is proposed.

  Patent Document 5 has both acid resistance and crack resistance by coating an organic-inorganic composite type coating curing agent on a mortar or concrete surface containing a calcium aluminate compound and ground granulated blast furnace slag, An anticorrosive composite capable of suppressing swelling and peeling of a coating layer has been proposed.

Patent Document 6, the alumina cement clinker over 20-330 parts by weight with respect to the alumina cement 100 parts by weight, and by including the hormite clay mineral 0.1-5.0 parts by weight, and improved鏝塗Ri workability Acid resistant mortar compositions have been proposed.

JP 2003-192423 A JP 2003-261372 A JP 2004-292245 A JP 2006-151733 A JP 2007-001803 A JP 2007-070153 A

  However, hydraulic compositions and mortar compositions containing an alumina cement-based material as the main component, even if the acid resistance is increased, the adhesion durability of the cured mortar obtained by the difference in acrylic resin is not sufficient Was also seen. For this reason, from the viewpoint of improving the long-term durability of the concrete structure and reducing the life cycle cost of the concrete structure, a mortar cured body having excellent corrosion resistance and such a mortar cured body are reliably formed. There is a need for a hydraulic composition and a mortar composition that are capable of achieving high strength, adhesion, and adhesion durability.

  Therefore, the present invention provides a mortar composition that can form a cured mortar that has excellent corrosion resistance (particularly acid resistance), adhesion, and adhesion durability, and that has excellent strength development, and its An object is to provide an acid-resistant hydraulic composition capable of preparing such a mortar composition. Moreover, an object of this invention is to provide the mortar hardening body which has the outstanding corrosion resistance (especially acid resistance) reliably.

  As a result of intensive studies to achieve the above object, the present inventors use an acid-resistant hydraulic composition containing alumina cement, alumina cement clinker, blast furnace slag, silica fume, fine aggregate, lithium carbonate and acrylic resin. Has found that a mortar composition and a cured mortar having stable acid resistance, strength development and adhesiveness can be obtained, and the present invention has been completed.

That is, the present invention is an acid-resistant hydraulic composition containing alumina cement, alumina cement clinker, blast furnace slag, silica fume, fine aggregate, lithium carbonate and acrylic resin, and 20 to 90% by mass of the blast furnace slag is 6000. A compound having a Blaine specific surface area of 10000 cm ² / g, containing 1 to 12 parts by mass of silica fume with respect to 100 parts by mass of alumina cement, and a compound having an isocyanate group as an acrylic resin as a crosslinking agent, a compound having an aziridine ring, The glass transition temperature (Tg) of the acrylic resin includes at least one selected from the group consisting of a compound having an oxazoline ring, a compound having a carbodiimide group, a compound having an epoxy group, and a compound having an alkoxysilyl group, Acid-resistant hydraulic resistance of 15 to -1 ° C To provide a Narubutsu.

  According to the acid-resistant hydraulic composition of the present invention, a mortar composition having excellent strength development can be prepared. Moreover, the hardened | cured mortar body which has the outstanding corrosion resistance (especially acid resistance), adhesiveness, and adhesion durability can be formed. In other words, the acid-resistant hydraulic composition of the present invention and water are blended and kneaded to prepare a mortar composition, which is applied to the surface of the concrete structure, cured and integrated, thereby providing excellent resistance. A concrete structure having corrosiveness and adhesiveness can be obtained. Such a concrete structure has excellent long-term durability.

  Preferred embodiments [(1) to (5)] of the acid-resistant hydraulic composition of the present invention are shown below. In the present invention, it is more preferable to appropriately combine these aspects.

  (1) It is preferable that the acid-resistant hydraulic composition of this invention contains 1-100 mass parts of blast furnace slag with respect to 100 mass parts of alumina cements. Thereby, a mortar hardened body having further excellent corrosion resistance and adhesiveness can be obtained. Moreover, the mortar composition which has the further outstanding strength expression can be obtained.

  (2) It is preferable that the acid-resistant hydraulic composition of this invention contains 0.001-0.1 mass part of lithium carbonate with respect to 100 mass parts of alumina cements. As a result, a mortar cured body having more excellent acid resistance and adhesiveness can be obtained. Moreover, the mortar composition which has the further outstanding strength expression can be obtained.

  (3) The acid-resistant hydraulic composition of the present invention preferably has a mass ratio of alumina cement to alumina cement clinker of 0.3 to 2.5. Thereby, a mortar hardened body having further excellent corrosion resistance and adhesiveness can be obtained. Moreover, the mortar composition which has the further outstanding strength expression can be obtained.

(4) The silica fume in the acid-resistant hydraulic composition of the present invention preferably has a BET specific surface area of 15 to 23 m ² / g and a bulk specific gravity of 100 to 600 kg / m ³ . Thereby, a mortar hardened body having further excellent corrosion resistance and adhesiveness can be obtained. Moreover, the mortar composition which has the further outstanding strength expression can be obtained.

(5) The blast furnace slag in the acid-resistant hydraulic composition of the present invention contains a first blast furnace slag and a second blast furnace slag having different brain specific surface areas, and the first blast furnace slag has a brain specific surface area. It is preferably 6000 to 10000 cm ² / g, and the second blast furnace slag preferably has a brane specific surface area of 3000 to 5800 cm ² / g. By including a plurality of types of blast furnace slag having different specific surface areas of branes as described above, it is possible to form a mortar cured body having further excellent corrosion resistance and adhesion.

  The present invention also provides a mortar composition containing the above acid-resistant hydraulic composition and water. Since the mortar composition of the present invention contains the acid-resistant hydraulic composition having the above characteristics, the mortar has excellent strength development and excellent adhesiveness, and has excellent corrosion resistance. A cured body can be formed.

  The mortar composition of the present invention preferably contains a synthetic resin emulsion. As a result, a mortar cured body having more excellent acid resistance and adhesiveness can be obtained.

  The present invention also provides a mortar cured product obtained by curing the mortar composition described above. Since the mortar cured body of the present invention contains the acid-resistant hydraulic composition and the mortar composition having the above characteristics, it has excellent corrosion resistance and adhesiveness.

  According to the present invention, a mortar composition capable of forming a cured mortar that has excellent corrosion resistance (particularly acid resistance), adhesion and adhesion durability, and has excellent strength development, and its It is possible to provide an acid-resistant hydraulic composition capable of preparing such a mortar composition. In addition, by using the above acid-resistant hydraulic composition and mortar composition, it is possible to provide a cured mortar that stably has excellent corrosion resistance (particularly acid resistance), adhesion, and adhesion durability. .

  The cured mortar body of the present invention can provide superior corrosion resistance, especially acid resistance, compared to conventional alumina cement-based acid mortar with improved corrosion resistance, so it should not be used in combination with lining methods such as synthetic resins. However, it has sufficiently long-term durability. For this reason, the initial cost of construction of a concrete structure can be suppressed. Furthermore, since it is excellent in adhesiveness, it contributes to improvement of long-term durability and reduction of life cycle cost by integrating with a concrete structure. Moreover, since the mortar composition of this invention is excellent in intensity | strength expression, it can shorten a construction period.

  Hereinafter, preferred embodiments of the present invention will be described. The acid-resistant hydraulic composition of the present embodiment includes alumina cement, alumina cement clinker, blast furnace slag, silica fume, fine aggregate, lithium carbonate, and acrylic resin. The acid-resistant hydraulic composition is a hydraulic composition having high acid resistance. Hereinafter, each component will be described in detail.

  Alumina cements are inherently excellent in acid resistance, and several types with different mineral compositions are known. Any alumina cement may be used for the acid-resistant hydraulic composition of the present embodiment. Among these, it is preferable to use an alumina cement having a monocalcium aluminate content of 50% by mass or more.

  The content of the alumina cement in the acid-resistant hydraulic composition of the present embodiment is preferably 30 to 50% by mass, more preferably 32 to 45% by mass.

  Alumina cement clinker is excellent in acid resistance because the mineral composition is basically the same as that of alumina cement. Moreover, the alumina cement clinker has very good binding properties with the alumina cement. In addition, since the alumina cement continuously hydrates, the transition of the alumina cement hydrate can be suppressed, and thereby excellent corrosion resistance can be sustained for a long time.

  The content of the alumina cement clinker in the acid resistant hydraulic composition of the present embodiment is preferably 30 to 60% by mass, more preferably 32 to 55% by mass.

  The mass ratio of alumina cement to alumina cement clinker (alumina cement / alumina cement clinker) is preferably 0.3 to 2.5, more preferably 0.5 to 2.0. The total content of alumina cement and alumina cement clinker in the acid-resistant hydraulic composition of the present embodiment is preferably 65 to 90% by mass, more preferably 70 to 85% by mass.

  When the content of the alumina cement clinker is too small, or when the mass ratio is too large, it may be difficult to obtain sufficiently excellent strength development and acid resistance. On the other hand, when the content of the alumina cement clinker is too large, or when the mass ratio is too small, shrinkage and cracks at the time of curing tend to occur, and workability of the glazing operation tends to decrease.

  The particle diameter of the alumina cement clinker is preferably 150 μm to 4 mm, more preferably 150 μm to 2.5 mm, and further preferably 150 μm to 2.0 mm. The maximum particle size of the alumina cement clinker is preferably 2.0 mm or less. As a result, the spraying workability and the wrinkling workability can be further improved. The particle diameter of the alumina cement clinker can be measured by using several sieves having different nominal dimensions as defined in JIS Z 8801-2006.

  Blast furnace slag is a common cement admixture, and any commercially available product can be used. Among these, it is preferable to use blast furnace slag fine powder prescribed | regulated by JIS A 6206-1997 "Blast furnace slag fine powder for concrete". The blast furnace slag has the effect of improving the strength of the hardened body due to the latent hydraulic property and the effect of suppressing the strength reduction due to the transfer of the alumina cement hydrate, like the alumina cement clinker. By using the above-mentioned blast furnace slag fine powder, a mortar cured body excellent in chemical reactivity, particularly acid resistance can be formed.

It is preferable that the blast furnace slag has a brain specific surface area in the range of 2000 to 10000 cm ² / g. Moreover, the ratio of the blast furnace slag (1st blast furnace slag) which has a Blaine specific surface area of 6000-10000 cm < ² > / g with respect to the whole blast furnace slag is 20-90 mass%. The ratio is more preferably 30 to 80% by mass, further preferably 35 to 70% by mass, and particularly preferably 40 to 60% by mass.

The ratio of the blast furnace slag having a brain specific surface area of 7000 to 9000 cm ² / g with respect to the entire blast furnace slag is preferably 20 to 90% by mass, more preferably 30 to 80% by mass, and 35 to 70% by mass. % Is more preferable, and 40 to 60% by mass is particularly preferable.

It is preferable that the blast furnace slag contains the first blast furnace slag having the above-mentioned brain specific surface area and the second blast furnace slag having a smaller brain surface area than the first blast furnace slag. Blaine specific surface area of the second blast furnace slag is preferably less than 6000 cm ² / g, more preferably 3000~5800cm ² / g.

  By including each blast furnace slag having the above-mentioned predetermined specific surface area of branes at a predetermined ratio, the acid resistance and strength development can be further improved. When the proportion of the first blast furnace slag having a large brain specific surface area is increased, the acid resistance tends to be improved, but the coating workability tends to be lowered and cracks tend to be generated. On the other hand, when the proportion of the second blast furnace slag having a small Blaine specific surface area increases, it is difficult to obtain sufficiently excellent acid resistance and strength development. Therefore, by containing the first blast furnace slag having a predetermined Blaine specific surface area in the above range, a mortar composition and a mortar cured body having further excellent characteristics can be obtained.

  The content of blast furnace slag is preferably 1 to 100 parts by weight, more preferably 3 to 50 parts by weight, still more preferably 7 to 30 parts by weight, particularly preferably 100 parts by weight of alumina cement. Is 10 to 20 parts by mass.

  By adjusting the content of the blast furnace slag to the above range, the acid resistance and the initial strength development can be further improved.

  Silica fume is a common cement admixture, and any commercially available product can be used. Among these, it is preferable to use a silica fume defined in JIS A 6207-2006 “Silica fume for concrete”. Such a silica fume has the effect of improving the glazing workability by the bearing effect as well as the effect of improving the strength of the cured body. Moreover, the mortar hardening body which was further excellent in durability can be formed.

The BET specific surface area of the silica fume is preferably 15 to 23 m ² / g, more preferably 16 to 22 m ² / g, still more preferably 17 to 21 m ² / g, and particularly preferably 18 to 20 m ² / g. g.

The bulk specific gravity of the silica fume is preferably 100 to 600 kg / m ³ , more preferably 150 to 400 kg / m ³ , still more preferably 200 to 350 kg / m ³ , and particularly preferably 250 to 300 kg / m ^3. It is.

  By setting the BET specific surface area and bulk specific gravity of the silica fume within the above ranges, it is possible to improve the glazing workability and further improve the strength development and durability.

  The content of silica fume is preferably 1 to 12 parts by mass, more preferably 2 to 10 parts by mass, further preferably 3 to 8 parts by mass, particularly preferably 100 parts by mass of alumina cement. 4 to 6 parts by mass.

  By setting the content of silica fume within the above range, it is possible to improve the glazing workability and further improve the strength development and durability. On the other hand, when the content of silica fume exceeds the above range, the coating workability tends to decrease due to an increase in viscosity, and sufficiently excellent acid resistance tends to be impaired.

  As the fine aggregate, it is preferable that the mass ratio of particles having a particle diameter of 1200 μm or more is less than 30 mass% with respect to the entire fine aggregate. As the most aggregate, for example, a material 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. In the present specification, the “mass ratio of particles having a particle diameter of 1200 μm or more” refers to the mass ratio of particles on the sieve when a sieve having a sieve mesh of 1200 μm is used.

  When the fine aggregate contains 20% by mass or more of coarse particles having a particle size of 1200 μm or more, the workability of the highly acid-resistant hydraulic composition tends to decrease. There is no restriction | limiting in particular in the lower limit of the said coarse grain part, and 0 mass% may be sufficient. In order to obtain excellent glazing workability, the coarse particle content in the fine aggregate is preferably 0 to 20% by mass, more preferably 5 to 17% by mass, and further preferably 8 to 15% by mass. It is particularly preferably 10 to 13% by mass.

  The content of the fine aggregate is preferably 5 to 90 parts by mass, more preferably 10 to 70 parts by mass, still more preferably 15 to 50 parts by mass, with respect to 100 parts by mass of the alumina cement. Preferably it is 10-40 mass parts.

  By adjusting the content of the fine aggregate to the above range, the acid resistance and the strength can be further improved while improving the glazing workability.

  It is preferable to use lithium carbonate having a particle size that does not interfere with the characteristics of the acid-resistant hydraulic composition. The maximum particle size of lithium carbonate is preferably 50 μm or less, more preferably 30 μm or less, still more preferably 20 μm or less, and particularly preferably 10 μm or less.

  By setting the maximum particle diameter of lithium carbonate within the above range, the solubility of lithium carbonate can be sufficiently increased, and the strength development and acid resistance can be further improved.

  The content of lithium carbonate is preferably 0.001 to 0.1 parts by mass, more preferably 0.004 to 0.07 parts by mass, and still more preferably 0.001 to 0.1 parts by mass with respect to 100 parts by mass of the alumina cement. It is 007-0.04 mass part, Most preferably, it is 0.01-0.02 mass part.

  By adjusting the lithium carbonate content to the above range, the hydration of alumina cement, alumina cement clinker and blast furnace slag can be promoted, and the strength development and acid resistance can be further improved.

  The acrylic resin in the acid-resistant hydraulic composition of the present embodiment has an effect of improving the adhesion to concrete and acid resistance. Examples of acrylic resins include (meth) acrylic acid such as acrylic acid and methacrylic acid; polymers of (meth) acrylic acid derivatives such as (meth) acrylic acid esters; copolymers of (meth) acrylic acid derivatives and styrene, etc. Is mentioned. Examples of (meth) acrylic acid esters include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate.

  The acrylic resin in the acid-resistant hydraulic composition of the present embodiment further comprises a compound having an isocyanate group as a crosslinking agent, a compound having an aziridine ring, a compound having an oxazoline ring, a compound having a carbodiimide group, a compound having an epoxy group, and an alkoxy It contains at least one selected from the group consisting of compounds having a silyl group. Adhesion durability improves by having a crosslinking agent. Among these, it is preferable to use a compound having an alkoxysilyl group as a crosslinking agent because the adhesion durability is further improved.

  The glass transition temperature (Tg) of the acrylic resin in the acid-resistant hydraulic composition of the present embodiment is -15 to -1 ° C, preferably -14 to -2 ° C, more preferably -13 to -3. ° C, particularly preferably -12 to -3 ° C. When such an acrylic resin is used, it has excellent adhesion durability even when the concrete substrate is in a wet state, and also has good workability.

  The glass transition temperature (Tg) of the acrylic resin is obtained by measuring the following conditions using a differential scanning calorimeter after an appropriate amount of an acrylic resin emulsion is dropped on a glass plate and dried to obtain a dry coating film. Can be measured. Specifically, first, the dried coating film was heated from room temperature to 150 ° C. in 10 minutes, held at 150 ° C. for 10 minutes, and then to a temperature 50 ° C. lower than the Tg of the sample obtained by calculation. Reduce the temperature. When the temperature falls, the temperature is raised again to 150 ° C. in 10 minutes. In the process, the first glass transition temperature (Tg) is measured, and then the second Tg is measured in the process of lowering the temperature to 50 ° C. lower than the Tg measured in the first, and the second Tg is measured. The value is the glass transition temperature of the acrylic resin.

  The acrylic resin in the acid-resistant hydraulic composition of the present embodiment is an acrylic resin emulsion in which acrylic resin particles are emulsified and dispersed in water or a water-containing solvent, or a re-emulsified acrylic resin powder pulverized by a spray drying method or the like. Preferably there is. An acrylic resin emulsion is more preferable from the viewpoint of miscibility.

  As for the content rate of solid content other than water or a water-containing solvent in the whole acrylic resin emulsion, 40-60 mass% is preferable. When the solid content is in the above-mentioned range, the acrylic resin emulsion is excellent in miscibility and storage stability, and more reliably exhibits the effect of improving the adhesion to concrete, adhesion durability and acid resistance. In addition, content of the solid content of an acrylic resin emulsion is the mass of the solid content which remained by evaporating the water | moisture content or water-containing solvent in an acrylic resin emulsion. A product obtained by subtracting the solid content from the acrylic resin emulsion is used as the water or water-containing solvent in the acrylic resin emulsion.

  The content of the acrylic resin (solid content) is preferably 1 to 10 parts by mass, more preferably 2 to 7 parts by mass, further preferably 100 parts by mass of the powder part of the acid-resistant hydraulic composition. Is 2.5 to 6 parts by mass, particularly preferably 3 to 5 parts by mass.

  By adjusting the content of the acrylic resin to the above range, the adhesion to concrete and the acid resistance can be further improved.

  By combining the acid-resistant hydraulic composition according to this embodiment with alumina cement, alumina cement clinker, blast furnace slag, silica fume, lithium carbonate, and acrylic resin in the above-described preferable range, sufficient strength development of the mortar composition is achieved. It is possible to form a mortar hardened body that is improved in terms of acid resistance and adhesion.

  Here, the powder part of the acid-resistant hydraulic composition means a powder part excluding the liquid component and the acrylic resin emulsion when the acid-resistant hydraulic composition contains a liquid component. In the case where the acid-resistant hydraulic composition does not include a liquid component and an acrylic resin emulsion and consists only of a powder component, the powder part of the acid-resistant hydraulic composition means the entire acid-resistant hydraulic composition. It will be.

  The acid-resistant hydraulic composition of the present embodiment may contain a lubricating powder, a fluidizing agent, a setting retarder, and a synthetic resin fiber, if necessary, in addition to the above-described essential components.

  The slippery powder can be appropriately added as long as the characteristics of the acid-resistant hydraulic composition of the present embodiment are not impaired. By using the slippery powder, it is possible to adjust the wiping workability and the spraying workability.

  The slippery powder has an effect of moderately reducing friction between the mortar composition and the wrinkles, for example, in a wrinkling operation. As the lubricious powder, soft inorganic components such as wax and talc can be preferably used. The particle size distribution (particle size distribution) of the lubricating powder is preferably 0.05 to 1500 μm, more preferably 0.09 to 1000 μm, still more preferably 0.12 to 700 μm, and particularly preferably. It is 0.15-500 micrometers.

  The content of the lubricating powder is preferably 1 to 30 parts by mass, more preferably 5 to 25 parts by mass, and further preferably 7 to 10 parts by mass with respect to 100 parts by mass of the alumina cement. Especially preferably, it is 9-15 mass parts.

  By adjusting the particle diameter and addition amount of the slippery powder to the above ranges, a preferable slipping effect can be obtained. In addition, the wiping workability and the spraying workability can be improved.

  The fluidizing agent can be appropriately added as long as the characteristics of the present invention are not impaired. If the content of the fluidizing agent in the acid-resistant hydraulic composition is appropriately adjusted, the flow value of the mortar composition prepared by kneading the acid-resistant hydraulic composition and water can be adjusted.

  The fluidizing agent is selected from commercially available fluidizing agents such as formaldehyde condensate of melamine sulfonic acid, casein, calcium caseinate, polycarboxylic acid, polyether, and polyether carboxylic acid, which have both water reduction effect and suitable fluidity. can do. As the fluidizing agent contained in the highly acid-resistant hydraulic composition of the present embodiment, it is particularly preferable to use a commercially available fluidizing agent such as polyether-based or polyether carboxylic acid. From the viewpoint of imparting a predetermined fluidity while maintaining acid resistance, the fluidizing agent preferably contains a polycarboxylic acid ester.

  The content of the fluidizing agent is preferably 0.02 to 1.00 parts by mass, more preferably 0.04 to 0.50 parts by mass, and still more preferably 0.07 to 0 parts with respect to 100 parts by mass of the alumina cement. .30 parts by mass, particularly preferably 0.10 to 0.20 parts by mass.

  By adjusting the content of the fluidizing agent to the above-described range, preferable fluidity can be imparted, and the tanning workability and the spraying workability can be improved.

  The setting retarder can be appropriately added within a range that does not impair the characteristics of the present invention, and the pot life (the time required for glazing or spraying) can be adjusted.

  A well-known thing can be used as a setting retarder. As an example, one kind selected from organic acids such as oxycarboxylic acids, sugars such as glucose, maltose and dextrin, sodium bicarbonate, sodium phosphate and the like can be used alone or in combination of two or more kinds.

  Examples of oxycarboxylic acids include oxycarboxylic acids and salts thereof. Examples of oxycarboxylic acid include citric acid, gluconic acid, tartaric acid, glycolic acid, lactic acid, hydroacrylic acid, α-oxybutyric acid, glyceric acid, tartronic acid, malic acid and other aliphatic oxyacids, salicylic acid, m-oxy Aromatic oxyacids such as benzoic acid, p-oxybenzoic acid, gallic acid, mandelic acid and tropic acid.

  Examples of the salt of oxycarboxylic acid include alkali metal salts (specifically sodium salt and potassium salt) and alkaline earth metal salts (specifically calcium salt, barium salt and magnesium salt). it can. Of these, sodium salts are preferred. Further, sodium tartrate is more preferable from the standpoints of setting delay effect, availability and price, and it is more preferable to use this sodium tartrate and sodium bicarbonate in combination.

  The content of the setting retarder is preferably 0.01 to 2 parts by mass, more preferably 0.1 to 1.5 parts by mass, and still more preferably 0.2 to 100 parts by mass of the alumina cement. It is -1.0 mass part, Most preferably, it is 0.3-0.5 mass part.

  By adjusting the content of the setting retarder to the above-mentioned range, it is possible to ensure a suitable pot life (spreading operation or spraying operation possible time).

  Synthetic resin fibers can be appropriately added as long as the characteristics of the present invention are not impaired. Synthetic resin fibers have the effect of improving the glazing workability and improving the crack resistance of the mortar cured body.

  As synthetic resin fiber, what consists of synthetic resin components, such as polyolefin, such as polyethylene, ethylene-vinyl acetate copolymer (EVA), a polypropylene, polyester, polyamide, polyvinyl alcohol, vinylon, and polyvinyl chloride, can be used. A synthetic resin fiber can be used individually by 1 type selected from these or in combination of 2 or more types.

  The fiber length of the synthetic resin fiber is preferably 0.5 from the viewpoint of handling properties when mixed with the high acid-resistant hydraulic composition, improved dispersibility in the high acid-resistant mortar composition, and improved characteristics of the mortar cured body. It is -15.0mm, More preferably, it is 1.0-12.0mm, More preferably, it is 2.0-8.0mm, Most preferably, it is 2.5-7.0mm.

  The content of the synthetic resin fiber is preferably 0.01 to 3 parts by mass, more preferably 0.03 to 1 part by mass, and further preferably 0.04 to 0. 3 parts by mass, particularly preferably 0.05 to 0.15 parts by mass.

  By adjusting the fiber length and content of the synthetic resin fiber to the above-described ranges, it is possible to improve the glazing workability and the crack resistance of the mortar cured body.

  Next, preferred embodiments of the mortar composition of the present invention will be described. The mortar composition of this embodiment can be prepared by blending and kneading the above acid-resistant hydraulic composition and water. Here, the flow value and unit volume mass of a mortar composition can be adjusted by changing the compounding quantity of water suitably. Therefore, a mortar composition suitable for the application can be prepared. 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 blending amount of water is preferably 2 to 18 parts by mass, more preferably 4 to 16 parts by mass, and still more preferably 8 to 12 parts by mass with respect to 100 parts by mass of the powder part of the acid-resistant hydraulic composition. Part, particularly preferably 9 to 11 parts by mass.

  When the mortar composition contains a synthetic resin emulsion, the amount of water needs to consider the amount of water in the synthetic resin emulsion. Therefore, it adjusts so that the total amount of the water to mix | blend and the water | moisture content in a synthetic resin emulsion may turn into the preferable amount of water mentioned above.

  The flow value of the mortar composition of this embodiment becomes like this. Preferably it is 145-200 mm, More preferably, it is 150-190 mm, More preferably, it is 155-180 mm, Most preferably, it is 160-175 mm.

  By setting the flow value of the mortar composition within the above-described range, it is possible to improve the coating workability and the spraying workability.

  The unit volume mass of the mortar composition of the present embodiment is preferably 2.05 to 2.55 kg / L (liter), more preferably 2.10 to 2.50 kg / L, and even more preferably 2. It is 15-2.45 kg / L, Most preferably, it is 2.20-2.40 kg / L.

  By setting the unit volume mass within the above-described range, it is possible to improve the wiping workability and the spraying workability.

  The cured mortar formed by curing the mortar composition of the present embodiment is excellent in corrosion resistance (particularly acid resistance). Next, a preferred embodiment of the mortar cured body of the present invention will be described.

  The mortar cured body of the present embodiment can be formed by curing the mortar composition described above. The high acid-resistant mortar cured body formed in this way has excellent strength (compressive strength, bending strength and adhesive strength) when integrated with a concrete structure. It is suitable as a body.

  Here, the compressive strength and the bending strength are values measured in accordance with a test method described in JIS R 5201-1997 “Physical Test Method for Cement”. In addition, the adhesive strength refers to the adhesion described in the "Corrosion Inhibition Technology and Corrosion Prevention Technology Manual for Sewerage Concrete Structures (edited by the Japan Sewerage Corporation, Regional Foundation, published by the Sewerage Business Support Center, April 2012)". It is a value measured according to the strength test.

The compressive strength at the age of 3 days mortar cured body to be measured by the above test method, is preferably 39N / mm ² or more, more preferably 40N / mm ² or more, more preferably 41N / mm ² or more Especially preferably, it is 42 N / mm ² or more.

The bending strength of the cured mortar as measured by the above-described test method is preferably 8.5 N / mm ² or more, more preferably 9.0 N / mm ² or more, and further preferably 9 and a .5N / mm ² or more, and particularly preferably 10.0 N / mm ² or more.

  By setting the compressive strength and the bending strength within the above ranges, the mortar cured body has excellent strength development when integrated with a concrete structure.

The indoor 7-day adhesive strength of the cured mortar body measured by the above test method is preferably 1.2 N / mm ² or more, more preferably 1.3 N / mm ² or more, still more preferably 1.4 N / mm ² or more, and particularly preferably 1.5 N / mm ² or more.

The adhesion strength at 3 months and 12 months of age of exposed cured material of the mortar cured body measured by the above test method is preferably 3.0 N / mm ² or more, more preferably 3.2 N / mm ^2. Or more, more preferably 3.4 N / mm ² or more, and particularly preferably 3.5 N / mm ² or more.

  By setting the adhesive strength within the above-mentioned range, the mortar cured body has excellent adhesion and adhesion durability when integrated with a concrete structure.

  In addition, it is preferable that no floating occurs between the cured mortar and the ground during outdoor exposure curing. The presence or absence of floating can be confirmed by hitting the surface of the mortar hardened body with a percussion stick and listening to the change in sound. When the float is not generated, the mortar cured body has excellent durable adhesiveness when integrated with the concrete structure.

  The mortar hardened body of the present embodiment has excellent acid resistance, and can suppress corrosion of the concrete structure for a long period of time. An example of the acid resistance index is sulfuric acid penetration depth (mm). This sulfuric acid penetration depth is the test described in the "Corrosion Inhibition Technology and Corrosion Prevention Technology Manual for Sewerage Concrete Structures (edited by the Japan Sewerage Corporation, published by the Sewage Works Support Center, April 2012)" It is a value measured according to the method (sulfuric acid penetration depth).

  The sulfuric acid penetration depth (sulfuric acid immersion 112 days) of the cured mortar is preferably 4.0 mm or less, more preferably 3.8 mm or less, still more preferably 3.6 mm or less, and particularly preferably 3. 5 mm or less.

  If the sulfuric acid penetration depth is within the above range, the cured mortar body has a more excellent acid resistance, so that corrosion of the concrete structure can be suppressed for a long period of time.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment. For example, the acid-resistant hydraulic composition, mortar composition, and mortar cured product of the present invention may contain components other than the above-described components to the extent that the effect is not significantly impaired.

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

(Examples 1-2, Comparative Examples 1-2)
[Preparation of highly acid-resistant hydraulic composition]
The raw materials shown in (1) to (11) below were prepared.

(1) Alumina cement ・ Alumina cement (Kelneos, Blaine specific surface area: 3100 cm ² / g, monocalcium aluminate content: 53 mass%)
(2) Alumina cement clinker Alumina cement clinker (manufactured by Kerneos, particle size: 1.0 mm or less, alumina content: 40% by mass)
(3) Blast furnace slag-Blast furnace slag A (JIS A 6206-1997, Blaine specific surface area 4660 cm ² / g)
・ Blast furnace slag B (JIS A 6206-1997, Blaine specific surface area 8320 cm ² / g)

(4) Silica fume Silica fume (JIS A 6207-2006, BET specific surface area: 19 m ² / g, bulk specific gravity: 280 kg / m ³ )
(5) Fine aggregate ・ Silica sand (coarse fraction having a particle diameter of 1200 μm or more: 11.7% by mass)
(6) Lithium carbonate ・ Lithium carbonate (maximum particle size: 3 μm)

(7) Lubricant powder ・ Wollastonite (particle size distribution: 0.2 to 120 μm)
(8) Fluidizer-Fluidizer (polycarboxylic acid ester fluidizer)
(9) Setting retarder-Setting retarder A (sodium bicarbonate)
-Setting retarder B (sodium tartrate)

(10) Synthetic resin fiber • Vinylon fiber (fiber length: 6 mm)
(11) Acrylic resin emulsion Acrylic resin emulsions A and B (monomer: including methyl methacrylate and 2-hydroxyethyl methacrylate, cross-linking agent: compound having alkoxysilyl group)
Acrylic resin emulsions C to E (monomer: containing methyl methacrylate and 2-hydroxyethyl methacrylate, no crosslinking agent)
In addition, Table 1 shows each glass transition temperature (Tg), solid content, and minimum film-forming temperature (MFT).

  The above-mentioned alumina cement, alumina cement clinker, blast furnace slag, silica fume, fine aggregate, lithium carbonate, lubricating powder, fluidizing agent, setting retarder, and synthetic resin fiber are blended in the proportions shown in Table 2, and each The powder part of the acid-resistant hydraulic composition of an Example and each comparative example was prepared.

[Preparation of mortar composition]
With respect to 100 parts by mass of the powder part of the acid-resistant hydraulic composition blended at the blending ratio shown in Table 2, water and an acrylic resin emulsion were blended at the ratio shown in Table 3 and kneaded to prepare a mortar composition. 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%. The physical properties of the mortar composition thus obtained were evaluated by the following methods.

[Method for evaluating physical properties]
(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". Table 3 shows the measurement results.
(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". Table 3 shows the measurement results.
(3) Measuring method of compressive strength and bending strength Based on the test method described in JIS R 5201-1997 "Physical testing method of cement", compressive strength and bending strength at the age of 28 days were measured. Table 3 shows the measurement results.
(4) Measurement method of adhesion strength As described in “Corrosion control technology and anti-corrosion technology manual for sewer concrete structures (edited by the Japan Sewage Works Agency, issued by the Japan Sewage Works Support Center, published in April 2012)” The measurement was performed according to a test method (adhesion strength test). In addition, for specimens for measurement of material age of 7 days and 28 days of age, for specimens for measurement at age of 3 months, 6 months and 12 months in a constant temperature room at room temperature of 20 ° C. One day after the preparation of the test specimen, it was cured in a thermostatic chamber at room temperature of 20 ° C., then exposed to the outdoors and cured to a predetermined age. Table 3 shows the measurement results.
(5) Method of measuring float The specimens (5 for each formulation) similar to the adhesive strength measuring method described above were cured in a thermostatic chamber at room temperature of 20 ° C. for 1 day, and then exposed outdoors. Then, the presence or absence of the occurrence of floating was confirmed using a percussion stick at every predetermined age. Here, “0/5” is a case where none of the five specimens are lifted, and “3/5” is the whole or part of each of the three specimens (for example, around the specimen). Part)), and “5/5” is the case where all five specimens floated on the entire surface or part thereof. Table 3 shows the measurement results.

(6) Sulfuric acid penetration depth measurement method "Corrosion control technology and anti-corrosion technology manual for sewer concrete structures (edited by the Japan Sewerage Corporation, published by the Sewage Works Support Center, April 2012)" It measured based on the test method (sulfuric acid penetration depth) of description. Specifically, first, a test specimen for measurement was produced by the following procedure. Three test pieces for measuring the sulfuric acid penetration depth were prepared for each of the following methods.

The preparation method of the test body was based on JIS A 1132-2006. The mortar composition was molded into a cylindrical mold having a diameter of 7.5 cm and a height of 15 cm, and demolded one day later to obtain a cured mortar. A specimen was prepared by curing in tap water at 20 ± 2 ° C. until the age of 28 days. This test body was immersed in a 5% by mass sulfuric acid aqueous solution (test solution) for 112 days. During this time, the test solution was replaced in its entirety every 7 days for the first 4 weeks and every 4 weeks thereafter. After completion of immersion, the test specimen taken out from the test solution is uniformly washed with tap water with the tap fully opened for 1 minute, and then the surface moisture is wiped off to obtain a test specimen for measuring the sulfuric acid penetration depth. It was. The reference amount of the test solution was 0.0044 m ³ (4.4 L) per test specimen.

  The test specimen for measuring the depth of penetration of sulfuric acid produced by the above method is cut with a diamond cutter or the like so that the height of the cylinder is halved, and a 1% by mass solution of phenolphthalein is sprayed on the cut surface. The length in the diameter direction of the red colored portion was measured with calipers at five locations. The initial value (75 mm) of the width of the specimen was subtracted from the average value of the measured values, and 1/2 of the value was defined as the sulfuric acid immersion depth (mm). About each method, the average value of the sulfuric acid immersion depth (mm) of three test bodies for a measurement was calculated | required. Table 3 shows the measurement results (average values).

  As shown in Table 3, the flow values of the mortar compositions of Examples 1 and 2 were in the range of 160 to 175 mm. From this result, it was confirmed that the mortar compositions of Examples 1 and 2 have good glazing workability and spraying workability.

  The unit volume mass of the mortar compositions of Examples 1 and 2 was in the range of 2.20 to 2.40 kg / L. From this result, it was confirmed that the acid-resistant hydraulic compositions of Examples 1 and 2 have good glazing workability and spraying workability.

Compressive strength of the mortar cured body of Example 1 and 2 are 42N / mm ² or more in the age of 7 days, the flexural strength was 9.5 N / mm ² or more in the age of 7 days. From this result, it was confirmed that the acid-resistant hydraulic compositions of Examples 1 and 2 have excellent strength development.

The adhesive strength of the cured mortars of Examples 1 and 2 is 1.5 N / mm ² or more at 7 days of age in indoor curing, 3 months of age in outdoor exposure curing, and 3.0 N of 12 months of age. / Mm < ² > or more, and since there was no occurrence of floating even at 12 months of age in outdoor exposure curing, it was confirmed that the film had excellent adhesion and adhesion durability.

  The sulfuric acid penetration depth of the cured mortars of Examples 1 and 2 at an age of 112 days was 4.0 mm or less. From this result, it was confirmed that the acid-resistant hydraulic compositions of Examples 1 and 2 surely had excellent corrosion resistance (particularly acid resistance).

  From the above, as in Examples 1 and 2, the acid-resistant hydraulic composition of the present invention is a cured mortar that stably has excellent corrosion resistance (particularly acid resistance), adhesion, and adhesion durability. It has been confirmed that it is possible to prepare a mortar composition capable of forming a mortar composition and having an excellent strength development property, and such a mortar composition. In addition, the cured mortar of the present invention provides corrosion resistance, particularly acid resistance, which is definitely superior to conventional alumina cement-based acid-resistant mortar with improved corrosion resistance. Even if not, it has a sufficiently long-term durability. For this reason, the initial cost of construction of a concrete structure can be suppressed. Furthermore, since it is excellent in adhesiveness, it contributes to improvement of long-term durability and reduction of life cycle cost by integrating with a concrete structure. Moreover, since the mortar composition of this invention is excellent in intensity | strength expression, it can shorten a construction period.

Claims (9)

An acid-resistant hydraulic composition comprising alumina cement, alumina cement clinker, blast furnace slag, silica fume, fine aggregate, lithium carbonate and acrylic resin,
20 to 90% by mass of the blast furnace slag has a Blaine specific surface area of 6000 to 10000 cm ² / g,
1 to 12 parts by mass of the silica fume with respect to 100 parts by mass of the alumina cement,
The acrylic resin was selected from the group consisting of a compound having an isocyanate group as a crosslinking agent, a compound having an aziridine ring, a compound having an oxazoline ring, a compound having a carbodiimide group, a compound having an epoxy group, and a compound having an alkoxysilyl group. Including at least one species,
The acid-resistant hydraulic composition whose glass transition temperature (Tg) of the said acrylic resin is -15--1 degreeC. The acid-resistant hydraulic composition according to claim 1, wherein the acrylic resin has a glass transition temperature (Tg) of -12 to -3 ° C. The acid-resistant hydraulic composition according to claim 1 or 2 , comprising 1 to 100 parts by mass of the blast furnace slag with respect to 100 parts by mass of the alumina cement. The acid-resistant hydraulic composition according to any one of claims 1 to 3, comprising 0.001 to 0.1 parts by mass of the lithium carbonate with respect to 100 parts by mass of the alumina cement. The acid-resistant hydraulic composition according to any one of claims 1 to 4 , wherein a mass ratio of the alumina cement to the alumina cement clinker is 0.3 to 2.5. The silica fume is a BET specific surface area of 15~23m ² / g, and a bulk specific gravity of 100~600kg / ^{m 3,} acid-resistant hydraulic composition according to any one of claims 1 to 5. The blast furnace slag contains a first blast furnace slag and a second blast furnace slag having different brain specific surface areas,
The first blast furnace slag has a brain specific surface area of 6000 to 10000 cm ² / g,
The acid-resistant hydraulic composition according to any one of claims 1 to 6, wherein the second blast furnace slag has a brain specific surface area of 3000 to 5800 cm ² / g. A mortar composition comprising the acid-resistant hydraulic composition according to any one of claims 1 to 7 and water. A mortar cured product obtained by curing the mortar composition according to claim 8 .