JP6446307B2 - 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 have improved corrosion resistance even if the acid resistance is improved, due to the difference in the chemical components of the alumina cement. Some cases were affected. 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 hydraulic compositions and mortar compositions that are capable of providing high strength and adhesion.

  Therefore, the present invention is capable of forming a mortar cured body having excellent corrosion resistance (particularly acid resistance) and adhesiveness, and has excellent strength development, and such a mortar composition. It is an object to provide an acid-resistant hydraulic composition that can be prepared. 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 diligent studies to achieve the above object, the present inventors achieved excellent results by using an acid-resistant hydraulic composition containing alumina cement, alumina cement clinker, blast furnace slag, silica fume, fine aggregate, and lithium carbonate. It was found that a mortar composition and a mortar cured body having stable acid resistance, strength development and adhesiveness were obtained, and the present invention was 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, and lithium carbonate, and the SiO ₂ content in the alumina cement is 2.0 to 7 .0 wt%, _Al 2 _{O 3} content of 25.0 to 65.0 wt%, _Fe 2 _{O 3} content is 0.5 to 20.0% by weight and CaO content 29.0 to 45.0 20% to 90% by mass of the blast furnace slag has a Blaine specific surface area of 6000 to 10000 cm ² / g, and the acid resistant water contains 1 to 12 parts by mass of silica fume with respect to 100 parts by mass of the alumina cement. A rigid composition is provided.

  According to the acid-resistant hydraulic composition of the present invention, a mortar composition having excellent strength development can be prepared. Moreover, the mortar hardening body which has the outstanding corrosion resistance (especially acid resistance) and adhesiveness reliably 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 (6)] 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) Acid resistance hydraulic composition of the present invention, the mineral composition of alumina cement, CA 50-90 _{wt%, C} 2 AS is 0 to 35 wt%, CA ₂ is 0 to 25 _{mass%, C 12} A ₇ is 0 to 20 mass%, _{C 3} A is 0 to 25 _{mass%, C} 4 AF is 0 to 30 mass%, _{C 2} S is 0 to 25% by weight, and 3 (CA) C S is 0-7 mass % Is preferred. 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) The acid-resistant hydraulic composition of the present invention preferably contains 1 to 100 parts by mass of blast furnace slag with respect to 100 parts by mass of alumina cement. 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.

  (3) 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.

  (4) 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.

(5) 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.

(6) 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.

  ADVANTAGE OF THE INVENTION According to this invention, the mortar composition which can form the mortar hardened | cured material which has excellent corrosion resistance (especially acid resistance) and adhesiveness reliably, and has the outstanding strength development, and such mortar composition It is possible to provide an acid-resistant hydraulic composition that can be prepared. Moreover, the mortar hardening body which has the outstanding corrosion resistance (especially acid resistance) and adhesiveness reliably can be provided by using the above-mentioned acid-resistant hydraulic composition and mortar composition.

  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, and lithium carbonate. The acid-resistant hydraulic composition is a hydraulic composition having high acid resistance. Hereinafter, each component will be described in detail.

Alumina cement is inherently excellent in acid resistance, and several types having different chemical components are known. In the acid resistant hydraulic composition of the present embodiment, the SiO ₂ content in the alumina cement is 2.0 to 7.0% by mass, the Al ₂ O ₃ content is 25.0 to 65.0% by mass, Fe a ₂ O ₃ content of 0.5 to 20.0% by weight and CaO content of 29.0 to 45.0% by weight, preferably, the SiO ₂ content in the alumina cement 2.5-6. 8 wt%, _Al 2 _{O 3} content of 30.0 to 64.0 wt%, _Fe 2 _{O 3} content is from 0.6 to 15.0% by weight and CaO content 30.0 to 44.0 mass More preferably, the SiO ₂ content in the alumina cement is 3.0 to 6.6% by mass, the Al ₂ O ₃ content is 33.0 to 63.0% by mass, and the Fe ₂ O ₃ content is Is 0.7 to 10.0% by mass and the CaO content is 31.0 to 43.0% by mass, more preferable. Is, SiO ₂ content in the alumina cement is from 3.5 to 6.4 wt%, _Al 2 _{O 3} content of 35.0 to 62.0 wt%, _Fe 2 _{O 3} content of 0.8 to 5 0.02 mass% and CaO content are 32.0-42.0 mass%, particularly preferably, SiO ₂ content in alumina cement is 4.0-6.0 mass%, Al ₂ O ₃ content. There 40.0 to 60.0 wt%, _Fe 2 _{O 3} content of 1.0 to 4.0% by weight and CaO content is 33.0 to 41.0 wt%.

  When the chemical component of the alumina cement is within the above range, excellent corrosion resistance can be obtained with certainty.

The chemical component of the alumina cement can be measured according to JIS R 2522: 1995 “Chemical analysis method of alumina cement for refractory”. The chemical components of the above-described "CaO", "SiO _2", the content of the _"Al 2 _{O 3"} and _"Fe 2 _{O 3"} is the content ratio to the total mass of the alumina cement (% by mass).

Blaine specific surface area of the alumina cement is preferably 2000~6000cm ² / g from the viewpoints of fluidity and curing properties, more preferably 2000~5000cm ² / g, more preferably from 2000~4000cm ² / g.

Further, the alumina _{cement, CaO · Al 2 O 3,} CaO · 2Al 2 O 3, 3CaO · Al 2 O 3, calcium aluminate such as _{12CaO · 7Al 2 O 3, 4CaO} · Al 2 O 3 · Fe 2 O Calcium aluminoferites such as ₃ , calcium silicates such as 2CaO · SiO ₂ , calcium aluminosilicates such as 2CaO · Al ₂ O ₃ · SiO ₂ , 3CaO · 3Al ₂ O ₃ · CaSO ₄ , CaO · TiO _2, etc. Various minerals can be included.

In this specification, CaO is C, Al ₂ O ₃ is A, SiO ₂ is S, Fe ₂ O ₃ is F, and SO ₃ is S. CaO · Al ₂ O ₃ , CaO · 2Al ₂ O ₃ , 3CaO _{· Al 2 O 3, 12CaO ·} 7Al 2 O 3 , _{respectively,} denoted _{CA, CA 2, C 3 a} , and _C 12 _{a 7,} denoted the _{4CaO · Al 2 O 3 · Fe} 2 O 3 and _C 4 AF the 2CaO · SiO ₂ is denoted as _{C 2} S, the _{2CaO · Al 2 O 3 · SiO} 2 is denoted as _C 2 aS, referred to _{3CaO · 3Al 2 O 3 · CaSO} 4 3 and (CA) C S.

  The mineral composition of the above-mentioned alumina cement is measured by analyzing powder X-ray diffraction data of the alumina cement by a profile fitting method. As the profile fitting method, a Rietveld analysis method or a WPF (Whole pattern fitting) analysis method is used (see Reference Document 1 below).

  Reference 1: Practical X-ray powder diffraction-Introduction to Rietveld method, Analytical Society of Japan, X-ray analysis research round-table [edit]

Mineral composition of alumina cement in acid resistance hydraulic composition according to this embodiment, preferably CA 50-90 _{wt%, C} 2 AS is 0 to 35 wt%, CA ₂ is 0 to 25 _{mass%, C 12} A ₇ is 0 to 20 mass%, _{C 3} A is 0 to 25 _{mass%, C} 4 AF is 0 to 30 mass%, _{C 2} S is 0 to 25% by weight, and 3 (CA) C S is 0-7 wt% And
More preferably, CA is 55 to 85 _{mass%, C} 2 AS 0 to 30 wt%, CA ₂ is 0 to 20 _{mass%, C} 12 _{A 7} is 0 to 15 mass%, _{C 3} A is 0 to 20 mass _{%, C} 4 AF is 0 to 25 mass%, _{C 2} S is 0 to 20% by weight, and 3 (CA) C S is from 0 to 5 wt%,
More preferably, CA 60 to 80 _{mass%, C} 2 AS 0 to 25 wt%, CA ₂ is 0 to 15 _{mass%, C} 12 _{A 7} is 0 to 10 mass%, _{C 3} A is 0-15 mass _{%, C} 4 AF is 0 to 20 mass%, _{C 2} S is 0 to 15% by weight, and 3 (CA) C S is 0 to 3 wt%,
Particularly preferably, CA is 65 to 75 _{mass%, C} 2 AS 0 to 20 wt%, CA ₂ is 0 to 10 _{mass%, C} 12 _{A 7} is 0-5 wt%, _{C 3} A 0-10 mass _{%, C} 4 AF 0 to 15 wt%, _{C 2} S is 0 to 10% by weight and 3 (CA) C S is 0 to 1 mass%.

  When the mineral composition of the alumina cement is within the above range, excellent corrosion resistance can be obtained more reliably.

  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 0.50 to 1.66, more preferably 0.58 to 1.40. 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, still more 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 the blast furnace slag is preferably 1 to 100 parts by mass, more preferably 3 to 50 parts by mass, still more preferably 7 to 30 parts by mass, particularly preferably 100 parts by mass of the 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.

  By using alumina cement, alumina cement clinker, blast furnace slag, silica fume and lithium carbonate in the above-mentioned preferred ranges in combination with the acid-resistant hydraulic composition according to this embodiment, the strength development of the mortar composition is sufficiently improved. Further, it is possible to form a mortar cured body having further excellent acid resistance and adhesiveness.

  The acid-resistant hydraulic composition of the present embodiment may contain a lubricating powder, a fluidizing agent, a setting retarder, a synthetic resin fiber, a synthetic resin emulsion, and the like as 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.

  The synthetic resin emulsion can be appropriately added as long as the characteristics of the present invention are not impaired. Synthetic resin emulsions have the effect of improving adhesion to concrete and acid resistance. Here, the synthetic resin emulsion refers to one in which synthetic resin particles are emulsified and dispersed in water or a water-containing solvent.

  The glass transition temperature (Tg) of the synthetic resin component contained in the synthetic resin emulsion is preferably 0 ° C. or higher, more preferably 5 ° C. or higher, and even more preferably 10 ° C. or higher. When such a synthetic resin emulsion is used, it has excellent adhesiveness even when the concrete base is in a wet state, and the workability is also good.

  The glass transition temperature (Tg) of the synthetic resin component contained in the synthetic resin emulsion is the following conditions using a differential scanning calorimeter after a suitable amount of the emulsion is dropped on a glass plate and dried to obtain a dry coating film. It can measure by measuring by. 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 defined as the glass transition temperature of the synthetic resin emulsion.

  As the synthetic resin emulsion, known building material emulsions such as acrylic emulsion and vinyl acetate emulsion can be used. That is, as a synthetic resin of the synthetic resin emulsion, (meth) acrylic acid, (meth) acrylic acid derivatives such as (meth) acrylic acid esters, α-olefin compounds such as ethylene and vinyl acetate, vinyl compounds such as styrene, butadiene, etc. Polymers or copolymers of polymerization components such as can be used.

  The synthetic resin emulsion is preferably an acrylic emulsion from the viewpoint of acid resistance. Examples of acrylic emulsions include (meth) acrylic such as acrylic acid and methacrylic acid; polymers of (meth) acrylic acid derivatives such as (meth) acrylic acid esters; polymers of (meth) acrylic acid derivatives and styrene. Can be mentioned. Examples of (meth) acrylic acid esters include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate.

  The content of the synthetic resin emulsion is preferably 1 to 10 parts by mass and more preferably 2 to 7 parts by mass in terms of solid content with respect to 100 parts by mass of the powder part of the acid-resistant hydraulic composition. Yes, more preferably 2.5-6 parts by mass, particularly preferably 3-5 parts by mass.

  The solid content of the synthetic resin emulsion is the mass of the solid content remaining after evaporation of the water in the synthetic resin emulsion. The water content in the synthetic resin emulsion is obtained by subtracting the solid content from the synthetic resin emulsion. Moreover, the powder part of an acid-resistant hydraulic composition means the powder part except a liquid component, when an acid-resistant hydraulic composition contains a liquid component. In the case where the acid-resistant hydraulic composition does not contain a liquid component and consists only of a powder component, the powder part of the acid-resistant hydraulic composition means the entire acid-resistant hydraulic composition.

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

  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 7-day-old adhesive strength of the mortar cured 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, and further preferably 1 and a .4N / mm ² or more, and particularly preferably 1.5 N / mm ² or more.

  By setting the adhesive strength within the above-described range, the mortar cured body has excellent adhesiveness when integrated with a 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 A to C (made by Kerneos, chemical components “SiO ₂ , Al ₂ O ₃ , Fe ₂ O ₃ , CaO” and Blaine specific surface area are shown in Table 1)

  The chemical component of the alumina cement shown in Table 1 is a content ratio (% by mass) with respect to the total mass, and was measured according to JIS R 2522: 1995 “Chemical analysis method of alumina cement for refractory”. The specific surface area of the brane was measured according to JIS R 5201: 1997 “Cement physical test method”.

[Mineral composition of alumina cement]
The mineral composition of the alumina cement was measured using a WPF analysis method using powder X-ray diffraction. Powder X-ray diffraction measurement uses a powder X-ray diffractometer RINT-2500 (manufactured by Rigaku Corporation), tube voltage 35 kV, tube current 110 mA, measurement range 2θ = 10-60 °, step width 0.02 °, count The time was 2 seconds, the conditions were a diverging slit: 1 ° and a light receiving slit: 0.15 mm.

For the WPF analysis method, JADE 6.0 (manufactured by Materials Data Inc.), which is a powder X-ray diffraction pattern comprehensive analysis software, was used. About the mineral composition shown in Table 2, the reference literature was made into the initial value, each crystal phase was refined and fitting was performed, and the mineral composition with the total amount of each mineral as 100 was measured. Table 3 shows the obtained mineral composition. Note that CaO is C, Al ₂ O ₃ is A, SiO ₂ is S, Fe ₂ O ₃ is F, and SO ₃ is S.

Reference 2: Ito, S., Suzuki, K., Inagaki, M., Naka, S. Mater. Res. Bull., V15
p925 (1980)
Reference 3: Louisnathan, SJ Can. Mineral., V10 p822 (1971)
Reference 4: Ponomarev VI, Kheiker DM, Belov NV Sov. Phys. Crystallogr.,
15, p995-998 (1971)
Reference 5: Natl. Bur. Stand. (US), Circ. 539, v9 p20 (1960)
Reference 6: Wong-Ng, W., McMurdie, H., Paretzkin, B., Hubbard, C., Dragoo, A.,
NBS (USA). ICDD Grant-inAid (1987)
Reference 7: Colville, AA, Geller, S. Acta Crystallogr., Sec. B, v27 p2311 (19
71)
Reference 8: Natl. Bur. Stand. (US) Monogr. 25, v19 p29 (1982)
Reference 9: Saalfeld H, Depmeier W Kristall und Technik 7 p229-233 (1972)

(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) Synthetic resin emulsion ・ Acrylic copolymer resin emulsion (solid content: 50 mass%, glass transition temperature (Tg): 23 ° C.)

  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 were blended in the proportions shown in Table 4, and each implementation The acid-resistant hydraulic composition (powder part) of Examples and Comparative Examples was prepared.

[Preparation of mortar composition]
With respect to 100 parts by mass of the acid-resistant hydraulic composition blended at a blending ratio shown in Table 2, water and a synthetic resin emulsion were blended at a ratio shown in Table 5 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 5 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 5 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 5 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). Table 5 shows the measurement results.

(5) Measurement method of sulfuric acid penetration depth “Manual of corrosion control and anti-corrosion technology for sewer concrete structures (edited by the Japan Sewerage Corporation, published by the Japan 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 test 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 5 shows the measurement results (average values).

  As shown in Table 5, 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 compositions of Examples 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 sulfuric acid penetration depth of the mortar compositions of Examples 1 and 2 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 can form a cured mortar that has excellent corrosion resistance (particularly acid resistance) and adhesiveness, And it was confirmed that it was possible to prepare the mortar composition which has the outstanding 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 (10)

An acid-resistant hydraulic composition comprising alumina cement, alumina cement clinker, blast furnace slag, silica fume, fine aggregate and lithium carbonate,
The alumina SiO ₂ content in cement 4.0 to 6.0 wt%, _Al 2 _{O 3} content of 30.0 to 64.0 wt%, _Fe 2 _{O 3} content of 0.6 to 15. 0 mass% and CaO content is 33.0-41.0 mass%,
20 to 90% by mass of the blast furnace slag has a Blaine specific surface area of 6000 to 10000 cm ² / g,
An acid-resistant hydraulic composition containing 1 to 12 parts by mass of the silica fume with respect to 100 parts by mass of the alumina cement. Mineral composition of the alumina cement, CA is 65 to 75 _{mass%, C} 2 AS is 0-20 wt%, CA ₂ is 0-10 _{mass%, C} 12 _{A 7} is 0-5 wt%, the _{C 3} A The acid-resistant hydraulic resistance according to claim 1, wherein 0 to 10 % by mass, C ₄ AF is 0 to 15 % by mass, C ₂ S is 0 to 10 % by mass, and 3 (CA) CS is 0 to 1% by mass. Composition.   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 acid-resistant hydraulic composition according to claim 1, wherein the silica fume 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 . 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.   The mortar composition according to claim 8, further comprising a synthetic resin emulsion.   A mortar cured product obtained by curing the mortar composition according to claim 8 or 9.