JP5953247B2 - Composition for mortar or concrete having improved frost damage resistance using blast furnace slag, molded product obtained by molding the composition, repair material and repair method - Google Patents

Description

  The present invention relates to a mortar or concrete composition having improved frost damage resistance using blast furnace slag, a molded product formed by molding the composition, a repair material, and a repair method.

  Conventionally, it has been known that the amount of air at the unloading point of ordinary concrete and its tolerance are 4.5% ± 1.5% as countermeasures against frost damage of concrete (for example, JIS A 5308 “Ready Mixed (See Concrete.) In addition, in an experiment by the civil engineering research institute, it has been confirmed that concrete entrained with air using an AE agent has frost resistance.

  On the other hand, as a technology related to measures against frost damage of concrete, for example, a cured body described in Patent Document 1 is known. The hardened body of this Patent Document 1 is obtained by improving the frost damage resistance of a hydrated solidified body of steel slag that is extremely inferior in frost damage resistance.

In addition, the present applicant has already proposed the technique of patent document 2 and Japanese Patent Application No. 2012-209747 regarding such a mortar or concrete composition. Patent Document 2 is a composition for mortar or concrete containing an amorphous blast furnace slag fine aggregate and a binder containing a fine powder of blast furnace slag having a specific surface area of 2500 to 7000 cm ² / g and a Portland cement. The mass ratio of Portland cement to the binder is 0.3 to 0.9. This mortar or concrete composition has a feature of excellent sulfuric acid resistance because a dihydrate gypsum layer is formed on the surface when used in an environment exposed to a sulfuric atmosphere such as a sewerage facility.

  Further, the technology of the above-mentioned Japanese Patent Application No. 2012-209747 is a mortar or concrete composition containing a blast furnace slag fine aggregate and a binder containing a blast furnace slag fine powder and Portland cement. The content of the blast furnace slag fine aggregate is 66.7% or more by mass ratio. This mortar or concrete composition uses blast furnace slag fine aggregate as a fine aggregate, so that the mortar or concrete becomes dense and high strength prevents chloride ion penetration. There is the feature that it is excellent.

JP 2004-299923 A JP 2010-001208 A

  By the way, in precast concrete produced through steam curing, the above-mentioned JIS standard for ready-mixed concrete is applied mutatis mutandis, and the air volume of 4.5% ± 1.5% is entrained using AE agent. As a countermeasure. However, the air that should have been introduced by the AE agent does not escape during steam curing, which may reduce the frost resistance. If no AE agent is used, there is a risk that it will be even lower. Actually, when the freeze-thaw test specified in JIS A 1148 “Concrete freeze-thaw test method” is performed on precast concrete produced using an AE agent, the relative dynamic elastic modulus at 300 freeze-thaw cycles is 60%. Often less than As described above, in general precast concrete products subjected to steam curing, resistance to frost damage has not been secured.

  Then, when this inventor earnestly researched about the frost damage resistance of concrete, it became clear that the composition containing many blast furnace slag as an aggregate or a binder has sufficient frost damage resistance. That is, it has been found that when a large amount of blast furnace slag is contained, the frost damage resistance is improved without using an AE agent. Based on the above findings, the present inventor has reached the following present invention excellent in frost damage resistance.

  The present invention has been made in view of the above, and provides a mortar or concrete composition having improved frost damage resistance using a blast furnace slag, a molded product formed by molding the same, a repair material, and a repair method The purpose is to do.

  In order to solve the above-described problems and achieve the object, a mortar or concrete composition according to the present invention is a mortar or concrete composition containing fine aggregate, a binder containing cement, and water. Freezing based on method A according to JIS A 1148 for a mortar or concrete specimen comprising a material comprising blast furnace slag in at least one of the fine aggregate or the binder and made of the mortar or concrete composition The relative kinematic elasticity coefficient at 300 freeze-thaw cycles in the thawing test is 60% or more, and the frost damage resistance is excellent.

  Another mortar or concrete composition according to the present invention is a salt water having a concentration of 10% by mass in a solution for immersing the mortar or concrete specimen used for the freeze-thaw test in the invention described above. Is also characterized by having freeze-thaw resistance.

  Another mortar or concrete composition according to the present invention is characterized in that, in the above-described invention, the material comprising the blast furnace slag is fine blast furnace slag powder.

  Another mortar or concrete composition according to the present invention is characterized in that, in the above-described invention, the material comprising the blast furnace slag is a blast furnace slag fine aggregate.

  Moreover, the composition for other mortar or concrete according to the present invention is characterized in that, in the above-described invention, a mass ratio of the blast furnace slag fine aggregate to the fine aggregate is 0.6 to 1.0. .

  Another mortar or concrete composition according to the present invention is characterized in that, in the above-described invention, a mass ratio of water to the binder is 0.25 to 0.40.

  Further, another mortar or concrete composition according to the present invention is the above-described invention, wherein the molded product obtained by molding the mortar or concrete composition is resistant to salt damage and frost damage, and further to their combined deterioration. It is characterized by excellent.

  Moreover, the molded article which concerns on this invention is a molded article formed by shape | molding the composition for mortar or concrete mentioned above.

  In addition, another molded article according to the present invention is a molded article obtained without adding an AE agent to the mortar or concrete composition described above, and is excellent in resistance to salt damage and frost damage, and further to their combined deterioration. It is characterized by.

  Further, another molded article according to the present invention is a molded article obtained by steam curing the mortar or concrete composition described above, and is excellent in resistance to salt damage and frost damage, and further to these combined deterioration. Features.

  Moreover, the repair material which concerns on this invention is comprised including the composition for mortar or concrete mentioned above, It is used for repair of the mortar surface or concrete surface, It is characterized by the above-mentioned.

  Moreover, the repair method which concerns on this invention repairs the mortar surface or concrete surface using the composition for mortar or concrete mentioned above, It is characterized by the above-mentioned.

  According to the composition for mortar or concrete according to the present invention, a composition for mortar or concrete containing fine aggregate, a binder containing cement, and water, the fine aggregate or the binder Relative motion at 300 freeze-thaw cycles in a freeze-thaw test based on method A according to JIS A 1148 for a mortar or concrete specimen containing a material composed of blast furnace slag in at least one of the mortar or concrete composition The elastic modulus is 60% or more, and it is excellent in frost damage resistance. Therefore, there is an effect that it is possible to provide a mortar or concrete composition excellent in frost damage resistance and a molded product formed by molding the same.

FIG. 1 is a diagram of a freeze-thaw test result using a salt solution having a concentration of 10% by mass in a solution in which a specimen is immersed, W / B = 40%, GGBF / B = 0%, fine aggregate: It is a figure at the time of setting it as 100% of hard sandstone crushed sand. FIG. 2 is a view of a freeze-thaw test result using a salt solution having a concentration of 10% by weight in a solution in which the specimen is immersed, W / B = 25%, GGBF / B = 0%, fine aggregate: It is a figure at the time of setting it as 100% of hard sandstone crushed sand. FIG. 3 is a view of a freeze-thaw test result using a salt solution having a concentration of 10% by mass in a solution in which the specimen is immersed, W / B = 40%, GGBF / B = 60%, fine aggregate: It is a figure at the time of setting it as 100% of hard sandstone crushed sand. FIG. 4 is a view of a freeze-thaw test result using a salt solution having a concentration of 10% by mass in a solution in which the specimen is immersed, W / B = 25%, GGBF / B = 60%, fine aggregate: It is a figure at the time of setting it as 100% of hard sandstone crushed sand. FIG. 5 is a diagram of the results of a freeze-thaw test using salt water having a concentration of 10% by weight in a solution in which the specimen is immersed, W / B = 40%, GGBF / B = 0%, blast furnace slag fine bone It is a figure at the time of setting it as material 100%. FIG. 6 is a view of a freeze-thaw test result using a salt solution having a concentration of 10% by mass in a solution in which the specimen is immersed, W / B = 25%, GGBF / B = 0%, blast furnace slag fine bone It is a figure at the time of setting it as material 100%. FIG. 7 is a diagram of the results of a freeze-thaw test using salt water having a concentration of 10% by mass in a solution in which the specimen is immersed, W / B = 40%, GGBF / B = 60%, blast furnace slag fine bone It is a figure at the time of setting it as material 100%. FIG. 8 is a view of a freeze-thaw test result using a salt solution having a concentration of 10% by mass in a solution in which the specimen is immersed, W / B = 25%, GGBF / B = 60%, blast furnace slag fine bone It is a figure at the time of setting it as material 100%. FIG. 9 is a diagram of the results of a freeze-thaw test using salt water having a concentration of 10% by weight in a solution in which the specimen is immersed, W / B = 40%, blast furnace slag fine aggregate 100%, antifoaming agent It is a figure at the time of setting it as nonAE by addition. FIG. 10 is a diagram of the results of a freeze / thaw test using salt water having a concentration of 10% by weight in a solution in which the specimen is immersed, W / B = 25%, blast furnace slag fine aggregate 100%, antifoaming agent It is a figure at the time of setting it as nonAE by addition. FIG. 11 is a diagram of the results of a freeze / thaw test using salt water having a concentration of 10% by weight in a solution in which the specimen is immersed, W / B = 40%, fine aggregate: hard sandstone crushed sand 100%, steam It is a figure at the time of not using curing and AE agent. FIG. 12 is a view of a freeze-thaw test result using a salt solution having a concentration of 10% by mass in a solution in which the specimen is immersed, W / B = 25%, fine aggregate: hard sandstone crushed sand 100%, steam It is a figure at the time of not using curing and AE agent. FIG. 13 is a diagram of the results of a freeze / thaw test using salt water having a concentration of 10% by weight in a solution in which the specimen is immersed, W / B = 40%, blast furnace slag fine aggregate 100%, steam curing, It is a figure at the time of not using AE agent. FIG. 14 is a diagram of a freeze-thaw test result using a salt solution having a concentration of 10% by weight in a solution in which the specimen is immersed, W / B = 25%, blast furnace slag fine aggregate 100%, steam curing, It is a figure at the time of not using AE agent. FIG. 15 is a view of a freeze-thaw test result using a salt solution having a concentration of 10% by mass in a solution in which the specimen is immersed, W / B = 40%, GGBF / B = 60%, steam curing, AE It is a figure at the time of not using an agent. FIG. 16-1 is a photograph of a normal concrete specimen during 100 cycles of a freeze-thaw test using salt water having a concentration of 10% by mass in a solution in which the specimen is immersed, and (1) is taken from the right side. (2) was taken from the left side. FIG. 16-2 is a photograph of the specimen of the present invention during 100 cycles of a freeze-thaw test using a salt solution having a concentration of 10% by mass in a solution in which the specimen is immersed, and (1) is from the right side. Photographed, (2) is photographed from the left side. FIG. 17-1 shows the measured value of the penetration amount of chloride ions after completion of the freeze-thaw test, and is a diagram when the AE agent is added and cured at room temperature. FIG. 17-2 shows the measured value of the penetration amount of chloride ions after completion of the freeze-thaw test, and is a diagram in the case of curing at room temperature without adding the AE agent. FIG. 17-3 shows the measured value of the penetration amount of chloride ions after completion of the freeze-thaw test, and is a diagram when steam curing is performed by adding an AE agent.

  DESCRIPTION OF EMBODIMENTS Embodiments of a mortar or concrete composition according to the present invention, a molded product formed from the composition, a repair material, and a repair method will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

  The composition for mortar or concrete according to the present invention is a composition for mortar or concrete containing fine aggregate, a binder containing cement, and water, and is at least one of the fine aggregate and the binder. Relative dynamic elastic modulus at 300 freeze-thaw cycles in a freeze-thaw test based on method A described in JIS A 1148 for a mortar or concrete specimen containing a material composed of blast furnace slag Is 60% or more, and has excellent freeze-thaw resistance (frost resistance). Here, in the freeze-thaw test of the present invention, it is an important point that 10% salt water (10% sodium chloride aqueous solution in mass percent concentration) is used in the solution in which the specimen is immersed. In general, a freeze-thaw test using salt water is a test under severer conditions than that using fresh water.

Here, the blast furnace slag is produced as a by-product when producing pig iron in the blast furnace, and its main components are CaO, SiO ₂ , Al ₂ O ₃ , and MgO. This blast furnace slag can be used in the form of blast furnace slag fine powder or blast furnace slag fine aggregate. In this case, the blast furnace slag fine powder is used as a binder, and the blast furnace slag fine aggregate is used as a fine aggregate.

  The blast furnace slag fine aggregate is an amorphous blast furnace slag fine aggregate. As the amorphous blast furnace slag fine aggregate, for example, blast furnace granulated slag obtained by quenching blast furnace slag with water and lightly crushed and added with an anti-caking agent can be used. The temperature of the molten blast furnace slag immediately before being rapidly cooled in the production of granulated blast furnace slag is 1400-1500 degrees, and by rapid cooling, it is consolidated without any atomic arrangement to the crystals, and is glassy (non-crystalline) It becomes. The quality of blast furnace slag fine aggregate is specified in JIS A 5011-1.

Moreover, the blast furnace slag fine aggregate has a density of, for example, 2.5 to 3.0 g / cm ³ . Thus, by using the blast furnace slag fine aggregate having a density in the range of 2.5 to 3.0 g / cm ³ , the frost resistance of the obtained mortar or concrete is enhanced. When the density of the blast furnace slag fine aggregate is less than 2.5 g / cm ³ , since the blast furnace slag fine aggregate is porous, the strength of the mortar and concrete using the blast furnace slag fine aggregate may be low, and 2.55 g / It is preferably cm ³ or more and 2.90 g / cm ³ or less, and more preferably 2.80 g / cm ³ or less.

Blast furnace slag fine powder is obtained by drying and pulverizing blast furnace granulated slag obtained by quenching blast furnace slag with water, and has a specific surface area of 2500 to 7000 cm ² / g in terms of a brain value. Thus, by using a blast furnace slag fine powder having a specific surface area of 2500 to 7000 cm ² / g as a brain value, a composition for mortar or concrete having excellent anti-frost damage performance can be obtained. When the specific surface area of the blast furnace slag fine powder used is less than 2500 cm ² / g in terms of the brain value, the initial strength may be deteriorated, and the specific surface area is preferably 3000 cm ² / g or more in terms of the brain value. More preferably, it is 3500 cm ² / g or more. On the other hand, when the specific surface area exceeds 7000 cm ² / g in terms of the brane value, the cost increases, the heat of hydration increases, the drying shrinkage strain increases, and there is a risk of causing initial defects in the concrete. Is preferably 6500 cm ² / g or less in terms of Blaine value, and more preferably 5000 cm ² / g or less.

  Examples of the cement used in the present invention include ordinary Portland cement, early-strength Portland cement, super early-strength Portland cement, moderately hot Portland cement, low-heat Portland cement, etc. Among them, it is preferable to use ordinary Portland cement.

  The composition for mortar or concrete of the present invention contains fine aggregate, a binder containing cement, and water, but the mass ratio of the cement (C) and the binder (B) (C / B) is preferably 0.3 to 0.9, more preferably 0.35 or more and 0.85 or less. When the mass ratio (C / B) is in such a range, the resulting mortar or concrete has good frost damage resistance.

  When the blast furnace slag fine powder is included as the binder, the mass ratio (GGBF / B) of the blast furnace slag fine powder (GGBF) to the binder (B) is preferably 0.1 to 0.7, More preferably, it is 0.15 or more and 0.65 or less. When the blast furnace slag fine aggregate is included as the fine aggregate, the mass ratio (BFS / S) of the blast furnace slag fine aggregate (BFS) to the fine aggregate (S) is set to 0.6 to 1.0. Is preferred.

  Of the mortar or concrete composition of the present invention, the concrete composition usually further comprises coarse aggregate, and the mortar or concrete composition is cured to obtain mortar or concrete. Here, as the amount of water used (W) in the mortar or concrete composition, the mass ratio (W / B) of water (W) to the binder (B) is 0.25 to 0.40, That is, it is preferable that water (W) is 25-40 mass parts with respect to 100 mass parts of binder (B). Moreover, as a usage-amount of the coarse aggregate in the composition for concrete, it is preferable that a coarse aggregate is 100-500 mass parts with respect to 100 mass parts of binder (B). In addition, the mortar or concrete composition of the present invention may further contain other components as long as the effects of the present invention are not impaired.

  The composition for mortar or concrete of the present invention is excellent in resistance to frost damage and also excellent in resistance to salt damage as described later. Therefore, in areas where salt damage and frost damage can occur in combination, such as construction of buildings that require salt resistance as well as frost damage resistance, and highways in mountainous areas where snow melting agents are sprayed in winter. It is particularly effective against this. In addition to these uses, for example, it is suitably used at sites where frost resistance and salt damage resistance of coastal structures, marine structures, waterway structures, road structures, retaining wall structures in cold regions are required. . At this time, the mortar or concrete composition of the present invention may be molded in advance and applied as a molded product (precast concrete product), or the mortar surface or concrete surface may be formed using the mortar or concrete composition of the present invention. It may be used in a repair mode (the repair method of the present invention). Here, the repair material of the present invention can be configured to include the mortar or concrete composition described above.

  Next, the effect of this invention is demonstrated using the freeze-thaw test result of FIGS. In this test, in order to confirm that the composition for mortar or concrete of the present invention is excellent in resistance to frost damage and salt damage, and further to their combined deterioration, salt water (mass percent The test based on the A method described in JIS A 1148 is conducted using a 10% aqueous sodium chloride solution). In general, a freeze-thaw test using salt water is a test under severer conditions than that using fresh water.

  Moreover, in FIGS. 1-15, the concrete specimen which added AE agent is described as "AE concrete", and the concrete specimen which does not add AE agent is described as "without AE agent" or "nonAE". . In addition, the curing method distinguishes between steam curing and room temperature curing (underwater curing). “B” means a binder, “GGBF” means blast furnace slag fine powder, “BFS” means blast furnace slag fine aggregate, and “S” means fine aggregate. “GGBF / B” is the amount of fine powder of blast furnace slag / binder, “BFS / S” is the amount of fine aggregate of blast furnace slag / total fine aggregate, and “W / B” is the ratio of water binder (water / The amount of binder). “Fine aggregate = 100% crushed sand” means that 100% hard sandstone crushed sand was used as the fine aggregate. The following test results are also considered to be the same for mortar made by removing coarse aggregate from concrete.

  Table 1 shows the composition of the concrete specimen used in this freeze-thaw test.

  As shown in FIG. 1, in the case of W / B = 40%, the AE agent was added and the room temperature curing was performed, and the relative kinematic modulus at 300 freeze-thaw cycles was 90% or more, which was sufficient. It can be seen that it has resistance to complex degradation. However, it can be seen that the steam-cured one and the one not added with the AE agent both have a relative kinematic modulus of 60% or less and low resistance to complex deterioration.

  As shown in FIG. 2, in the case of W / B = 25%, for those to which the AE agent was added, the relative kinematic elasticity coefficient at 300 freeze-thaw cycles was 90% or more, and sufficient resistance to complex deterioration. It turns out that it has sex. However, it can be seen that those without the AE agent have a relative kinematic modulus of 60% or less and low resistance to complex deterioration.

  As shown in FIG. 3, in the case of W / B = 40% containing fine blast furnace slag powder, for those added with the AE agent, the relative dynamic elastic modulus at 300 freeze-thaw cycles is 90% or more, It can be seen that it has sufficient resistance to complex degradation. However, in the case where the AE agent is not added, the relative kinematic elastic modulus becomes 60% or less before 300 cycles in normal temperature curing, and rapidly decreases just before 300 cycles in steam curing. It turns out that the nature is low.

  As shown in FIG. 4, in the case of W / B = 25% containing the blast furnace slag fine powder, it is natural that the AE agent is added, and the one not added is also the relative movement after 300 freeze-thaw cycles. It can be seen that the elastic modulus is 90% or more, and it has sufficient resistance to complex deterioration.

  As shown in FIG. 5, in the case of W / B = 40% including the blast furnace slag fine aggregate, the freeze-thaw cycle 300 for the AE agent added and the steam-cured one not added with the AE agent. It can be seen that the relative dynamic elastic modulus at the time is 90% or more, and it has sufficient resistance to complex deterioration. However, it can be seen that those with room temperature curing to which no AE agent is added have a relative kinematic modulus of 60% or less and low resistance to complex degradation.

  As shown in FIG. 6, in the case of W / B = 25% including blast furnace slag fine aggregate, it is natural that the AE agent is added, and the case where the AE agent is not added is also relative at 300 freeze-thaw cycles. It can be seen that the kinematic elastic modulus is 90% or more, and it has sufficient resistance to complex deterioration.

  As shown in FIG. 7, in the case of W / B = 40% containing the blast furnace slag fine aggregate and the blast furnace slag fine powder, it is natural that the AE agent is added and the one not added is also freeze-thaw cycle. It can be seen that the relative kinematic modulus at 300 times is 90% or more, and it has sufficient resistance to complex deterioration. In addition, it can be seen that when blast furnace slag fine powder and blast furnace slag fine aggregate are used, sufficient resistance to combined deterioration is exhibited even if the AE agent is not used and steam curing is performed.

  As shown in FIG. 8, in the case of W / B = 25% containing the blast furnace slag fine aggregate and the blast furnace slag fine powder, it is natural that the AE agent is added and the one not added is also freeze-thawed cycle. It can be seen that the relative kinematic modulus at 300 times is 90% or more, and it has sufficient resistance to complex deterioration. In addition, it can be seen that when blast furnace slag fine powder and blast furnace slag fine aggregate are used, sufficient resistance to combined deterioration is exhibited even if the AE agent is not used and steam curing is performed.

  As shown in FIG. 9, in the case of W / B = 40%, which is completely nonAE with an antifoaming agent, those containing blast furnace slag fine aggregate and blast furnace slag fine powder, and room temperature curing not containing blast furnace slag fine powder In the case of No. 1, the relative kinematic elasticity coefficient at 300 freeze-thaw cycles is 90% or more, and it can be seen that it has sufficient resistance to complex deterioration. In addition, it can be seen that when blast furnace slag fine powder and blast furnace slag fine aggregate are used, sufficient resistance to combined deterioration is exhibited even if the AE agent is not used and steam curing is performed. However, in the case of steam curing that does not include blast furnace slag fine powder, the relative dynamic elastic modulus is 90% or less before 300 cycles.

  As shown in FIG. 10, in the case of W / B = 25% which is completely nonAE with an antifoaming agent, there are those containing blast furnace slag fine aggregate and blast furnace slag fine powder, and those containing no blast furnace slag fine powder. Regardless of the curing method, it can be seen that the relative kinematic modulus at 300 freeze-thaw cycles is 90% or more, and it has sufficient resistance to complex deterioration. In addition, it can be seen that when blast furnace slag fine powder and blast furnace slag fine aggregate are used, sufficient resistance to combined deterioration is exhibited even if the AE agent is not used and steam curing is performed.

  As shown in FIGS. 11 and 12, in the case of steam curing in which the AE agent is not used, it can be understood that the resistance to the combined deterioration is improved as the amount of blast furnace slag fine powder mixed is increased.

  As shown in FIGS. 13 and 14, in the case of steam curing in which no AE agent is used, the relative kinematic elasticity coefficient at 300 freeze-thaw cycles is 90% or more regardless of the amount of blast furnace slag fine powder mixed. It can be seen that it has sufficient resistance to complex deterioration. In addition, it can be seen that when blast furnace slag fine powder and blast furnace slag fine aggregate are used, sufficient resistance to combined deterioration is exhibited even if the AE agent is not used and steam curing is performed.

  As shown in FIG. 15, in the case of steam curing in which the AE agent is not used, it can be understood that the resistance to the combined deterioration is improved as the amount of the blast furnace slag fine aggregate is increased. In particular, it can be seen that when 67% or more of blast furnace slag fine aggregate is used as the fine aggregate, the resistance to the combined deterioration becomes very large.

  FIG. 16-1 is a photograph of a specimen of ordinary concrete during 100 cycles of the above-described freeze-thaw test. This specimen corresponds to the one without AE agent (steam curing) in FIG. FIG. 16-2 is a photograph of the specimen of the present invention during 100 cycles of the freeze / thaw test. This specimen corresponds to the one without AE agent (steam curing) in FIG. From the photographs of FIGS. 16-1 and 16-2, the specimen of the present invention is superior in resistance to composite deterioration as compared with a normal concrete specimen not containing blast furnace slag fine powder and blast furnace slag fine aggregate. I understand.

  Furthermore, after completion of the above freeze-thaw test results, the amount of chloride ions penetrating into the specimen was measured. An example of the result is shown in FIGS. 17-1 to 17-3. FIG. 17A is a diagram in the case of adding an AE agent and curing at room temperature. FIG. 17-2 is a diagram in the case of room temperature curing without adding the AE agent. FIG. 17-3 is a diagram when the AE agent is added and steam curing is performed. In each figure, “C / B = 40%” means “GGBF / B = 60%”. As shown in FIG. 17-1 to FIG. 17-3, when blast furnace slag fine powder and blast furnace slag fine aggregate are used, the amount of chloride ions penetrated is smaller than when not used at all, and sufficient It can be seen that it has salt resistance.

  Therefore, according to the mortar or concrete composition containing blast furnace slag fine powder and blast furnace slag fine aggregate among the present invention, the composition and molding for mortar or concrete having excellent resistance to combined deterioration due to frost damage and salt damage. Goods can be provided. In addition, since the molded product obtained without adding the AE agent and the molded product obtained by steam curing are excellent in frost damage resistance, the present invention is effective as a frost resistance countermeasure for precast concrete products. It is.

  Moreover, according to the concrete product using the molded article of the present invention, it has not only frost damage resistance but also salt damage resistance. For this reason, for example, when the present invention is applied to a structure in an environment where there is a possibility of salt damage such as a coastal or marine structure in a cold region, excellent anti-frost damage performance and salt damage resistance performance are exhibited. The service life of the structure can be extended compared to the case of ordinary mortar or concrete.

  As described above, the mortar or concrete composition according to the present invention is a mortar or concrete composition containing fine aggregate, a binder containing cement, and water, and the fine bone A freeze-thaw cycle in a freeze-thaw test based on method A according to JIS A 1148 for a mortar or concrete specimen made of the mortar or concrete composition, wherein at least one of the materials or the binder comprises blast furnace slag. The relative dynamic elastic modulus at 300 times is 60% or more, and it is excellent in frost resistance. Therefore, there is an effect that it is possible to provide a mortar or concrete composition excellent in frost damage resistance and a molded product formed by molding the same.

  As described above, the composition for mortar or concrete according to the present invention and the molded product obtained by molding it, and the repair material and the repair method are useful for steam-cured mortar and concrete products that do not use an AE agent, In particular, since it is excellent in resistance to salt damage and frost damage, and further combined degradation, it is suitable for mortar and concrete products used in coastal areas and cold areas where salt damage and frost damage may occur.

Claims (10)

A composition for mortar or concrete containing fine aggregate containing blast furnace slag fine aggregate, binder containing cement and blast furnace slag fine powder , and water, and containing no agent capable of entraining air. ,
The mass ratio of water to the binder is 0.25 to 0.40, the mass ratio of the blast furnace slag fine powder to the binder is 0.20 to 0.60, and the mass of the blast furnace slag fine aggregate to the fine aggregate The relative dynamic elastic modulus at 300 freeze-thaw cycles in the freeze-thaw test based on the method A described in JIS A 1148 for a mortar or concrete specimen prepared with the mortar or concrete composition having a ratio of 0.33 or more is A composition for mortar or concrete which is 60% or more and has excellent frost damage resistance. A fine aggregate comprising a blast furnace slag fine aggregate, a binder containing no unrealized blast furnace slag cement, containing water contains no agent has the ability to entrain air mortar or concrete composition Because
Produced through steam curing with the mortar or concrete composition having a mass ratio of water to binder of 0.25 to 0.40 and a mass ratio of blast furnace slag fine aggregate to fine aggregate of 0.33 or more. A mortar characterized by having a relative kinematic elasticity coefficient of 60% or more in a freeze-thaw cycle of 300 times in a freeze-thaw test based on the method A described in JIS A 1148 for a mortar or concrete specimen, and having excellent frost damage resistance Or a composition for concrete. A composition for mortar or concrete containing fine aggregate containing blast furnace slag fine aggregate, binder containing cement and blast furnace slag fine powder , and water, and containing no agent capable of entraining air. ,
The mass ratio of water to the binder is 0.25 to 0.40, the mass ratio of blast furnace slag fine powder to the binder is 0.60 or less, and the mass ratio of blast furnace slag fine aggregate to fine aggregate is 0. Relative dynamic elastic modulus at 300 freeze-thaw cycles in a freeze-thaw test based on method A described in JIS A 1148 for a mortar or concrete specimen prepared through steam curing with the mortar or concrete composition of 33 or more Is a composition for mortar or concrete, characterized by having a frost resistance of 60% or more and excellent frost resistance. The freeze-thaw resistance is provided even if the concentration of the solution in which the mortar or concrete specimen used for the freeze-thaw test is immersed is 10% by weight in salt water . The composition for mortar or concrete according to one. The mortar according to any one of claims 1 to 4 , wherein the molded article formed by molding the mortar or the concrete composition is excellent in resistance to salt damage and frost damage, and further to combined deterioration thereof. Or a composition for concrete. A molded article formed by molding the mortar or concrete composition according to any one of claims 1 to 5 . The molded article according to claim 6 , which is a molded article obtained without adding an AE agent to the mortar or concrete composition, and is excellent in resistance to salt damage and frost damage, and combined deterioration thereof. The molded article according to claim 6 or 7 , which is a molded article obtained by steam curing the mortar or concrete composition, and is excellent in resistance to salt damage and frost damage, and further combined deterioration thereof. . A repair material comprising the mortar or concrete composition according to any one of claims 1 to 5 and used for repairing a mortar surface or a concrete surface. A repair method comprising repairing a mortar surface or a concrete surface using the mortar or concrete composition according to any one of claims 1 to 5 .