JP6326820B2 - Repair method for concrete structures - Google Patents

Description

  The present invention relates to a method for repairing concrete used for concrete cross-section repair and the like.

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

Patent Documents 1 to 3 are known as cross-sectional restoration materials used in repair methods for concrete structures in the civil engineering and construction fields. Patent Document 1 discloses Portland cement, a BET specific surface area of 0.1% as a cement-based cross-sectional repair material that can stably have both high sulfuric acid resistance and high medium- and long-term strength development properties without degrading workability. A highly durable cross-sectional restoration material comprising 75 to 3.0 m ² / g of slag, fly ash or / and metakaolin powder, silica fume and quicklime-based expansion material. In addition to this, there is disclosed a highly durable cross-sectional repair material comprising one or more of a polymer dispersion or a re-emulsifying powder resin, a water retention agent, and a dispersant.

  Patent Document 2 discloses a cross-section repair material and a cross-section repair method that can repair a cross-section of a concrete structure that has a short construction time and excellent initial crack resistance, such as cement, rapid hardening material, polymer, basalt fiber, and bone. A cross-sectional repair material comprising a material, a cross-section repair material in which the rapid hardening material contains calcium aluminate and gypsum, and a cross-section repair method using the same are disclosed.

Patent Document 3 describes a mortar-type restoration material that has good workability during manufacturing and restoration work, and is particularly suitable for plastering work such as plastering. As a mortar restoration material that is substantially free of deterioration, deformation, floatation, peeling and cracking, and excellent in terms of durability, Al ₂ O ₃ is 15 to 40% by mass and SiO ₂ is 40 to 90% by mass. A mortar restorative material comprising hollow inorganic particles having a particle size of 50 μm or less, a cellulose-based water retention agent, an expansion material, and a metakaolin having a Blaine specific surface area of 8000 to 120,000 cm ² / g. Furthermore, a mortar restoration material containing at least one of polymer dispersion or re-emulsified powder resin, pozzolanic reactant, fiber and water reducing agent is disclosed.

  In Patent Document 4, the polymer dispersion and the re-emulsified powder resin are not blended and used, and the workability such as pumpability and paintability is excellent. As a highly durable cement mortar coating material that can be integrated, it contains a dispersant containing naphthalenesulfonic acid formalin condensation polymer as an active ingredient, a water retention agent containing cellulose derivatives as an active ingredient, an antifoaming agent, cement, and fine aggregate. A cement mortar coating material is disclosed.

JP 2007-161507 A JP 2008-050213 A JP 2009-084092 A JP 2012-140278 A

  The conventional method of repairing a concrete structure with a mortar composition using a cross-section restoration material was able to obtain an appropriate compressive strength and bending strength when integrated with the concrete structure. In order to obtain sufficient adhesiveness, it was necessary to use a polymer dispersion or a re-emulsified resin powder.

  However, in the restoration of concrete structures in water treatment facilities such as water purification and water use facilities, construction of concrete structures with mortar compositions using cross-section restoration materials that do not contain polymer dispersion, re-emulsified resin powder and / or fiber A method may be required and sufficient adhesion is also required. In addition, even if the adhesiveness is sufficient, if it does not contain polymer dispersion or re-emulsified resin powder and / or fiber, it will be post-construction in an outdoor environment where the temperature, humidity, wind speed, sunshine, etc. change every moment. Since surface cracks may occur during curing, there is a need for a method for repairing a concrete structure with a mortar composition using a cross-sectional repair material that is also excellent in crack resistance.

  Therefore, the present invention forms a hardened mortar that has good workability, has sufficient adhesiveness when integrated with a concrete structure, and has excellent crack resistance even under outdoor construction environment conditions. It is an object of the present invention to provide a method for repairing a concrete structure with a mortar composition using a cross-sectional restoration material.

  As a result of intensive studies to achieve the above object, the present inventors include Portland cement, calcium carbonate fine powder, inorganic expansion material, fine aggregate, fluidizing agent and cellulosic thickener. The method of repairing a concrete structure with a mortar composition using a cross-sectional restoration material containing a polycarboxylic acid copolymer and a specific amorphous silica fine powder, and a cellulosic thickener having a specific viscosity is good. It was found that it has workability, has sufficient adhesion to integrate with a concrete structure, and is excellent in crack resistance even under outdoor construction environment conditions, and has completed the present invention.

  That is, in the present invention, a mortar construction process for constructing a mortar composition prepared by mixing and kneading a cross-sectional repair material and water at a place where a part of a concrete structure is removed, and curing the mortar composition. A method of repairing a concrete structure having a cured body forming step of forming a mortar hardened body at the location, wherein the cross-sectional repair material is Portland cement, calcium carbonate fine powder, inorganic expansion material, fine aggregate, A cross-sectional repair material comprising a fluidizing agent and a cellulose-based thickener, the fluidizing agent comprising a polycarboxylic acid copolymer and amorphous silica fine powder, wherein the amorphous silica fine powder is contained in the fluidizing agent. 20-80 mass% of powder is contained, and the cellulose thickener provides the repair method of a concrete structure whose viscosity of 2% aqueous solution in 20 degreeC is 80-2000 mPa * s.

  The method for repairing a concrete structure according to the present invention uses a cross-sectional repair material and a mortar composition containing specific components for repairing the concrete structure, so that it has good workability and is integrated with the concrete structure. When this is done, it is possible to form a mortar cured body having sufficient adhesion and excellent crack resistance. As described above, in the method for repairing a concrete structure of the present invention, the reason why the mortar cured body has sufficient adhesion without containing a polymer dispersion or a re-emulsified resin powder is not necessarily clear, but as one of the reasons. In addition, each of the components contained in the cross-sectional repair material interacts with each other, and in particular, the specific calcium carbonate fine powder and the specific fluidizing agent (specific amorphous silica fine powder as an inorganic component in a specific ratio) It is considered that the action produced by the combination of the fluidizing agent) having a specific viscosity and the cellulose-based thickener having a specific viscosity contributes to the improvement of adhesion and crack resistance.

  The method for repairing a concrete structure of the present invention is preferably in the following manner. Moreover, as for the repair method of the concrete structure of this invention, it is more preferable to combine the following aspects suitably.

  The fine aggregate of the cross-sectional restoration material used in the method for repairing a concrete structure of the present invention has a particle size of 600 μm or more and a particle mass ratio of less than 1180 μm of 10 to 45% by mass, and a particle size of 150 μm. It is preferable that the mass ratio of the particles which are not less than 300 μm is 1 to 15 mass%. Thereby, the mortar hardening body which has more sufficient adhesiveness can be obtained. The workability during repair can be further improved.

  The cross-sectional restoration material used in the method for repairing a concrete structure according to the present invention is 10 to 50 parts by mass of calcium carbonate fine powder, 5 to 15 parts by mass of an inorganic expansion material, and 100 to 185 fine aggregates with respect to 100 parts by mass of Portland cement. It is preferable to contain a mass part, 0.01-0.3 mass part of superplasticizers, and 0.01-0.20 mass part of a cellulose thickener. Thereby, it becomes possible to obtain a mortar composition having better workability. Moreover, it becomes possible to obtain the mortar hardened | cured material which has more sufficient adhesiveness and the outstanding crack resistance, and can improve the durability of the concrete structure after repair.

  The cross-sectional restoration material used in the method for repairing a concrete structure of the present invention preferably further includes a material separation reducing agent, and the material separation reducing agent is preferably a polymer synthetic copolymer. Thereby, it becomes possible to obtain a mortar composition having better workability. Moreover, it becomes possible to obtain the mortar hardening body which has the further outstanding crack resistance, and can improve the durability of the concrete structure after repair.

  According to the present invention, it is possible to form a cured mortar that has good workability and has excellent adhesion when combined with a concrete structure and excellent crack resistance even under outdoor construction environment conditions. A possible method of repairing a concrete structure can be provided. The method for repairing a concrete structure of the present invention is suitably used for cross-sectional repair of a concrete structure.

  The mortar hardened body obtained by the method for repairing a concrete structure of the present invention has a long-term durability by being integrated with a concrete structure because it has excellent adhesion and excellent crack resistance even under outdoor construction environment conditions. It can contribute to the improvement of the property and the reduction of the life cycle cost.

It is a schematic diagram which shows an example of the concrete structure which has a degradation part to which the repair method of the concrete structure of this invention is applied. It is a schematic diagram which shows the concrete structure after removing the part containing a degradation part from the concrete structure of FIG. It is a schematic diagram which shows the concrete structure after the antirust agent was apply | coated to the reinforcing bar. It is a schematic diagram which shows the concrete structure in which the primer layer was formed on the inner wall surface of a recessed part. It is a schematic diagram of the concrete structure after applying a mortar composition once to a recessed part. It is a schematic diagram of the concrete structure by which the mortar composition was filled in the recessed part and integrated with the mortar composition by performing the mortar construction process. It is a schematic diagram which shows the construction method by a spraying construction method. 4 is a powder X-ray diffraction pattern of inorganic components contained in fluidizing agent A. FIG. 3 is a powder X-ray diffraction diagram of an inorganic component contained in fluidizing agent B. FIG.

  A preferred embodiment of a method for repairing a concrete structure according to the present invention will be described below. The method for repairing a concrete structure according to the present embodiment includes a deteriorated concrete removing process for removing a portion including a deteriorated portion of the concrete structure, and a kneaded mixture of a cross-sectional repair material containing a predetermined component and water at the removed portion. Repair method (repair method) of a concrete structure having a mortar construction process for constructing the prepared mortar composition and a cured body forming process for curing the mortar composition to form a mortar cured body at the above-mentioned location It is. Hereinafter, details of each step will be described with reference to the drawings.

  FIG. 1 is a schematic diagram illustrating a partial surface and a cross section of a concrete structure 100 having a deteriorated portion to which the method for repairing a concrete structure of the present embodiment is applied. That is, FIG. 1 (A) is a view showing the surface of the concrete structure 100 having a deteriorated portion, and FIG. 1 (B) is a line (b)-(b) of the concrete structure 100 in FIG. 1 (A). It is sectional drawing which shows a cross section typically.

  A concrete structure 100 shown in FIG. 1 has concrete portions 11 and 12 and reinforcing bars 13 and 15 embedded in the concrete portions 11 and 12.

  The deteriorated concrete removing step is a step of removing a portion including a deteriorated portion of the concrete structure. Specifically, first, a deteriorated concrete portion 12 (deteriorated portion) is specified by an examination such as appearance observation and a sounding method. Next, an area 14 including the concrete portion 12 and a part of the healthy concrete portion 11 around the concrete portion 12 is determined so that the deteriorated concrete portion 12 is completely removed from the concrete structure 100. To do. This region 14 is a place where the concrete structure 100 is removed. The area 14 can be removed by removing the concrete in the area 14 from the concrete structure 100.

  Specifically, first, on the surface of the concrete structure 100 as shown in FIG. 1A, an incision of about 10 mm is made in the depth direction from the concrete surface along the region 14 using an electric cutter or the like. Then, depending on the size of the area 14 to be picked up, a hammer, a hand breaker, a shot blast, a water jet or the like is appropriately selected to pick up the concrete in the area 14 [FIG. 1 (B)].

  FIG. 2 is a schematic diagram showing a surface and a cross section of the concrete structure 101 from which a portion including a deteriorated portion is removed. That is, FIG. 2 (A) is a view showing the surface of the concrete structure 101 from which the portion including the deteriorated portion has been removed, and FIG. 2 (B) is a diagram (b)-() of the concrete structure 101 in FIG. 2 (A). b) It is sectional drawing which shows typically the cross section in a line.

  In the deteriorated concrete removing step, as shown in FIGS. 2A and 2B, a concrete structure 101 from which a portion including the deteriorated portion has been removed is obtained. The concrete structure 101 has a concave portion formed by scraping concrete, and the concave portion is corroded with rust, and the reinforcing bar 15 with rust adhered to the surface portion and a part of the non-corroded reinforcing bar 13 And are exposed. Rust of the reinforcing bar 15 can be removed by a technique such as a wire brush or shot blasting.

  FIG. 3 is a schematic diagram showing a reinforcing bar to which a rust preventive material is applied and a surface and a cross section of a concrete structure 102 having the reinforcing bar. That is, FIG. 3 (A) is a view showing the reinforcing bar to which the rust preventive material 16 is applied and the surface of the concrete structure 102 having the reinforcing bar, and FIG. 3 (B) is the concrete structure 102 of FIG. 3 (A). It is sectional drawing which shows typically the cross section in the (b)-(b) line | wire.

  The rust preventive material 16 can be applied to the rebar 15 from which rust has been removed. Moreover, as shown in FIG. 3, you may apply the rust preventive material 16 also to the exposed part of the reinforcing bar 13 which is not corroded. As the rust preventive material 16, a polymer cement-based rust preventive material containing a cement composition, a synthetic resin (polymer), a rust preventive component, water and the like can be suitably used. In application, a brush, a lysing gun or the like can be appropriately selected and used. At this time, it is preferable to apply so that there is no unapplied portion on the surface of the reinforcing bar 15.

  FIG. 4 is a schematic view showing a surface and a cross section of the concrete structure 103 in which the primer layer 17 is formed on the inner wall surface of the recess. 4A is a view showing the surface of the concrete structure 103 in which the primer layer 17 is formed on the inner wall surface of the recess, and FIG. 4B is a view of the concrete structure 103 in FIG. 4A. It is sectional drawing which shows typically the cross section in the (b)-(b) line.

  The primer layer 17 can be formed by applying the water absorption adjusting agent (primer) so as to cover the inner wall surface of the recess formed by scraping, and then drying the water absorption adjusting agent. As a water absorption adjusting agent, a synthetic resin emulsion diluted with water can be suitably used. In applying the water absorption adjusting agent, a brush, a lysing gun or the like can be appropriately selected and used.

  Moreover, after apply | coating so that the inner wall surface of the recessed part formed by removing may be covered with water instead of the above-mentioned water absorption regulator (primer), it can also move to the mortar construction process which is the next process. In applying water (water dampening), a brush, a roller, or the like can be appropriately selected and used.

  The mortar construction step is a step of filling a concave portion of a concrete structure with a mortar composition 18 prepared by blending and kneading a cross-sectional repair material and water. In this step, it is preferable to apply the mortar composition in several steps after forming the primer layer 17.

  The mortar composition 18 is prepared by blending and kneading a cross-sectional repair material and water in a predetermined ratio. Kneading is performed using a mixer or the like until uniform. As the mixer, a hand mixer or a mortar mixer can be appropriately selected and used. The cross-sectional repair material and mortar composition used here will be described later.

If the area of the portion (concave portion) filled with the mortar composition 18 (the area of the region 14 in FIG. 1A) on the surface of the concrete structure 103 (FIG. 4A) is less than 10 m ² , the plastering method It is preferable to perform the construction. In the plastering method, a plasterer craftsman puts an appropriate amount of a mortar composition on a mortar board, and rubs the region 14 using a metal hammer or the like, and coats it in several times. In the first construction, for example, a thickness of about 5 mm is applied. In the second and subsequent constructions, the application is repeated with a thickness of 10 mm or less. The coating thickness for one day is preferably about 30 mm.

  FIG. 5 is a schematic diagram showing a surface and a cross section of the concrete structure 104 after the mortar composition is applied once in the recesses. That is, FIG. 5 (A) is a figure which shows the surface of the concrete structure 104 after applying a mortar composition once in a recessed part, FIG.5 (B) is (() of the concrete structure 104 of FIG. 5 (A). It is sectional drawing which shows typically the cross section in line b)-(b).

  In the case of construction by the plastering method, the last construction is finished with a flat surface so that the mortar composition and the concrete structure are integrated.

  FIG. 6 is a schematic diagram showing a surface and a cross section of a concrete structure 105 in which a mortar composition is filled in a recess and integrated with the mortar composition by performing a mortar construction process. That is, FIG. 6 (A) is a view showing the surface of the concrete structure 105 integrated with the mortar composition by filling the recess with the mortar composition by performing the mortar construction process, and FIG. It is sectional drawing which shows typically the cross section in the (b)-(b) line | wire of the concrete structure 105 of FIG. 6 (A).

When the area of the portion (concave portion) filled with the mortar composition 18 (the area of the region 14 in FIG. 1A) is 10 to 100 m ^{2 on} the surface of the concrete structure 104, the construction can be performed by a spraying method. preferable.

  FIG. 7 is a schematic diagram showing a construction method by a spraying method. The spraying method is a method of filling the recess (not shown in FIG. 7) with the mortar composition 18 by spraying the mortar composition 18 onto the concrete structure 20. As shown in FIG. 7, the apparatus used for the spraying method can include a mixer 21, a mortar pump 22 with a hopper, an air source 23, a pressure hose 24, and a spray gun 25. As an apparatus used for the spraying method, a hopper and a mortar pump may be separated.

  In the spraying method, it is preferable that the mortar composition is sprayed in several times on the recess formed by scraping the deteriorated part. In the first construction, as shown in FIG. 5, the mortar composition is sprayed to a thickness of, for example, about 5 mm. And the construction after the 2nd repeats spraying of the mortar composition so that it may become the thickness within 30 mm, respectively. In the final construction, the repair mortar composition is sprayed so as to have a thickness of about 15 mm. Thereafter, the surface of the mortar composition is finished flat with scissors so that the concrete structure and the mortar composition filled in the recesses are integrated. Thereby, as shown in FIG. 6, the mortar composition 18 is filled in the concave portion, and the concrete structure 105 integrated with the mortar composition 18 is obtained. Then, when the mortar composition 18 is dried, it becomes a mortar cured body, and a concrete structure integrated with the mortar cured body is obtained.

  A repaired concrete structure can be obtained by the repair method as described above. When the mortar hardened body obtained by this method is integrated with a concrete structure, it has sufficient adhesion to the concrete structure. For this reason, the concrete structure repaired by the repair method of this embodiment contributes to the improvement of long-term durability and the reduction of life cycle cost. Therefore, it is suitable as a repair method for a deteriorated concrete structure.

  Moreover, since the repair method of this embodiment uses the specific cross-section repair material and mortar composition, workability | operativity is also favorable. The cross-sectional repair material and mortar composition used in the repair method of the present embodiment can be suitably used in a concrete structure repair method using a plastering method or a spraying method.

  Next, an example of a cross-sectional repair material used in the method for repairing a concrete structure according to this embodiment will be described. In the concrete structure repair method of the present embodiment, since the cross-sectional restoration material as described below is used, it has good workability and sufficient adhesion to the concrete structure when integrated with the concrete structure. It is possible to obtain a concrete structure having a mortar hardened body with

  The cross-sectional repair material used in the method for repairing a concrete structure according to this embodiment is used for repairing concrete. The cross-sectional restoration material of this embodiment is a cross-sectional restoration material containing Portland cement, calcium carbonate fine powder, an inorganic expansion material, a fine aggregate, a fluidizing agent, and a cellulosic thickener.

  The fluidizing agent contained in the cross-sectional restoration material used in the method for repairing a concrete structure of the present embodiment includes a polycarboxylic acid copolymer and amorphous silica fine powder, and the fluidizing agent is amorphous. 20-80 mass% of silica fine powder is contained, and the viscosity of a 2% aqueous solution at 20 ° C. of the cellulose-based thickener is 80-2000 mPa · s. The mortar composition obtained by blending and kneading such a cross-sectional repair material and water has good workability. Moreover, if this mortar composition is used, the mortar hardening body provided with sufficient adhesiveness and the outstanding crack resistance when integrated with a concrete structure can be obtained. Hereinafter, each component included in the cross-sectional repair material used in the present embodiment will be described in detail.

  Portland cement is a common hydraulic material, and any commercially available product can be used. Among these, it is preferable to use Portland cement specified by JIS R 5210: 2009 “Portland cement”.

  As the calcium carbonate fine powder, an ordinary commercially available product can be used. Among these, it is preferable to use calcium carbonate fine powder (cold stone powder) with high whiteness.

  The calcium carbonate fine powder has a particle diameter of 150 μm or more and a particle mass ratio of less than 300 μm of less than 20 mass%, a particle diameter of 75 μm or more and a particle mass ratio of less than 150 μm of 10-50 mass. It is preferable that it is mass%. By including the calcium carbonate fine powder having a particle diameter in the above-mentioned range, the cross-sectional repair material of the present embodiment can sufficiently secure the time for applying the mortar composition, and exhibits good strength. Can be obtained.

  Moreover, it is preferable that a calcium carbonate fine powder does not contain the particle | grains whose particle diameter is 300 micrometers or more. Thereby, favorable intensity | strength expression can be obtained.

  The particle diameter of the calcium carbonate fine powder can be measured by using several sieves having different nominal sizes as defined in JIS Z8801-1: 2006 “Test sieve—Part 1: Metal mesh sieve”. . Further, in this specification, “a mass ratio of particles having a particle diameter of 150 μm or more and less than 300 μm” means that when a sieve having a sieve size of 300 μm is used, the sieve passes through a sieve having a sieve size of 300 μm, and When a sieve having a mesh size of 150 μm is used, it means the mass ratio of particles remaining on the sieve having a mesh size of 150 μm to the whole calcium carbonate fine powder.

  The content of the calcium carbonate fine powder in the cross-sectional restoration material used in the method for repairing a concrete structure of the present embodiment is preferably 10 to 50 parts by mass, more preferably 15 to 45 parts per 100 parts by mass of Portland cement. It is a mass part, More preferably, it is 15-40 mass parts, Most preferably, it is 20-35 mass parts.

  By containing the calcium carbonate fine powder in the above-described preferable range, it is possible to sufficiently secure the time for applying the mortar composition and to obtain a good strength expression.

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

  The content of the inorganic expansion material in the cross-sectional restoration material used in the method for repairing a concrete structure of the present embodiment is preferably 5 to 15 parts by mass, more preferably 6 to 13 parts by mass with respect to 100 parts by mass of Portland cement. Part, more preferably 7 to 12 parts by weight, and particularly preferably 8 to 11 parts by weight.

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

  As the fine aggregate, those selected from sands such as quartz sand, river sand, land sand, sea sand, and crushed sand can be suitably used.

  In the fine aggregate, the mass ratio of particles having a particle diameter of 600 μm or more and less than 1180 μm is 10 to 45 mass%, and the mass ratio of particles having a particle diameter of 150 μm or more and less than 300 μm is 1 to 15 mass%. The mass ratio of particles having a particle diameter of 600 μm or more and less than 1180 μm is preferably 15 to 40 mass%, and the particle ratio of particles having a particle diameter of 150 μm or more and less than 300 μm. More preferably 2 to 10% by mass, particles having a particle size of 600 μm or more and less than 1180 μm in a mass ratio of 20 to 37% by mass, particles having a particle size of 150 μm or more and less than 300 μm Is more preferably 3 to 8% by mass, and the mass of particles having a particle diameter of 600 μm or more and less than 1180 μm It is particularly preferable that the proportion of particles having a ratio of 25 to 35% by mass, a particle diameter of 150 μm or more and less than 300 μm is 4 to 7% by mass.

  When the particle diameter of the fine aggregate is within the above range, a mortar hardened body having more sufficient adhesiveness can be obtained. Moreover, the mortar composition which has the more outstanding construction property can be obtained.

  Moreover, it is preferable that a fine aggregate does not contain the particle | grains whose particle diameter is 1180 micrometers or more. Thereby, the mortar hardening body which has much more sufficient adhesiveness can be obtained. Moreover, the mortar composition which has the more outstanding construction property can be obtained.

  The particle diameter of the fine aggregate can be measured by using several sieves having different nominal sizes as defined in JIS Z8801-1: 2006 “Test sieve—Part 1: Metal mesh sieve”. In the present specification, “the mass ratio of particles having a particle diameter of 600 μm or more and less than 1180 μm” means that when a sieve having a sieve mesh of 1180 μm is used, the sieve passes through a sieve having a sieve mesh of 1180 μm, and When a sieve having a mesh size of 600 μm is used, it means a mass ratio of particles remaining on the sieve having a mesh size of 600 μm to the whole fine aggregate.

  The content of fine aggregate in the cross-sectional restoration material used in the method for repairing a concrete structure of the present embodiment is preferably 100 to 185 parts by mass, more preferably 110 to 175, with respect to 100 parts by mass of Portland cement. It is a mass part, More preferably, it is 115-170 mass parts, Most preferably, it is 120-165 mass parts.

  By making the content of fine aggregate in the cross-sectional restoration material within the above range, it has better workability, and when it is integrated with the concrete structure, it has a compressive strength equal to or higher than that of the concrete structure. A mortar cured product can be obtained.

  The fluidizing agent contains a polycarboxylic acid copolymer and amorphous silica fine powder, and contains 20 to 80% by mass of amorphous silica fine powder in the fluidizing agent. Thereby, while having the outstanding workability, the mortar hardening body which has sufficient adhesiveness when integrated with a concrete structure can be formed. In particular, the combined use of the above-mentioned calcium carbonate fine powder and the fluidizing agent strengthens the bond at the interface where the concrete structure and the mortar hardened body are integrated, and provides sufficient adhesiveness.

  The remainder obtained by removing the above-mentioned amorphous silica fine powder from the above-mentioned fluidizing agent is preferably a polycarboxylic acid copolymer. However, the third component can be included as long as the characteristics of the present invention are not impaired.

  Here, the amorphous nature of the amorphous silica fine powder is determined by a powder X-ray diffraction pattern (diffraction peak pattern) obtained by measurement using a powder X-ray diffractometer. If the diffraction pattern does not have a sharp diffraction peak and has only a gently curved baseline, it is determined to be amorphous.

  The fine powder of amorphous silica contained in the above-mentioned fluidizing agent is preferably 30 to 75% by mass, more preferably 40 to 70% by mass, and still more preferably based on the whole fluidizing agent. It is 45-65 mass%, Most preferably, it is 50-60 mass%.

  By setting the amorphous silica fine powder contained in the fluidizing agent in the above range, it becomes more reliable to form a cured mortar having sufficient adhesion when integrated with a concrete structure.

In the above-mentioned amorphous silica fine powder, SiO ₂ is preferably more than 90% by mass, more preferably more than 95% by mass, further more preferably more than 97% by mass, and particularly preferably more than 98% by mass as a chemical component. And, _Al 2 _{O 3} is preferably less than 10 wt% as chemical components, more preferably less than 5 wt%, more preferably less than 3 wt%, less than 2 wt% is especially preferred.

  When the chemical component of the amorphous silica fine powder contained in the fluidizing agent is within the above range, it is more reliable to form a mortar cured body having sufficient adhesion when integrated with a concrete structure. Become.

  Here, the chemical component of the amorphous silica fine powder can be measured using a fluorescent X-ray analyzer.

  The content of the fluidizing agent in the cross-sectional restoration material used in the method for repairing a concrete structure of the present embodiment is preferably 0.01 to 0.30 parts by mass, more preferably 100 parts by mass with Portland cement. Is 0.05 to 0.27 parts by mass, more preferably 0.07 to 0.23 parts by mass, and particularly preferably 0.10 to 0.20 parts by mass.

  By setting the content of the fluidizing agent in the cross-sectional repair material in the above range, preferable fluidity can be imparted, and the drapeability and sprayability can be improved. Moreover, the mortar hardening body which has sufficient adhesiveness when integrated with a concrete structure can be formed.

  Cellulose thickeners are cellulose containing water-soluble cellulose derivatives such as methylcellulose, ethylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, hydroxymethylalkylcellulose, hydroxypropylmethylcellulose, hydroxyethylmethylcellulose, glyoxal-added hydroxypropylmethylcellulose, carboxymethylcellulose and carboxyethylcellulose. Mention may be made of system thickeners.

  Further, the viscosity of the 2% aqueous solution at 20 ° C. of the cellulose-based thickener is 80 to 2000 mPa · s, preferably 100 to 1500 mPa · s, more preferably 150 to 1000 mPa · s, and particularly preferably. Is 200 to 600 mPa · s.

  When the viscosity of the 2% aqueous solution of the cellulose-based thickener at 20 ° C. is in the above range, the crack resistance of the mortar cured body is improved. In particular, the combined use of the above-mentioned calcium carbonate fine powder, the above-mentioned fluidizing agent, and the cellulose-based thickener strengthens the bond at the interface between the concrete structure and the mortar hardened body, and provides sufficient adhesion. And excellent crack resistance can be obtained even under outdoor construction environment conditions. When the viscosity is less than 80 mPa · s, the crack resistance is lowered and no excellent effect is obtained. Moreover, when a viscosity exceeds 2000 mPa * s, a viscosity will become high and the workability | operativity of a mortar composition may be inhibited.

  Here, the “viscosity” of the cellulosic thickener means that a 2% aqueous solution of the thickener is obtained by using a B-type viscometer (digital viscometer manufactured by BROOKFIELD: RVDV-1 +) with a rotor No. 4. A value measured at a rotational speed of 12 rpm and 20 ° C.

  The content of the cellulosic thickener in the cross-sectional restoration material used in the method for repairing a concrete structure of the present embodiment is preferably 0.01 to 0.20 parts by mass with respect to 100 parts by mass of Portland cement. More preferably, it is 0.02-0.14 mass part, More preferably, it is 0.04-0.12 mass part, Especially preferably, it is 0.06-0.10 mass part.

  If the content of the cellulose-based thickener is too small, it becomes difficult to obtain excellent crack resistance. On the contrary, when the content of the cellulosic thickener in the mortar composition is excessive, the viscosity of the mortar composition tends to increase, and workability may be lowered. For this reason, it is preferable that content of a cellulose thickener is the said range.

  The cross-section restoration material used in the method for repairing a concrete structure according to this embodiment can further suitably use a material separation reducing agent as long as the characteristics of the present invention are not impaired. The material separation reducing agent is preferably a polymer synthetic copolymer, and the viscosity of a 2% aqueous solution at 20 ° C. is preferably 2000 to 8000 mPa · s, more preferably 2500 to 6500 mPa · s, and still more preferably. Is 3000-5500 mPa · s, particularly preferably 3500-5000 mPa · s.

  When the viscosity of the 2% aqueous solution of the material separation reducing agent at 20 ° C. is within the above range, it can be expected that sufficient shape retention is obtained while having good workability. On the other hand, if the viscosity of the 2% aqueous solution of the material separation reducing agent at 20 ° C. exceeds 8000 mPa · s, the viscosity becomes high and the workability of the mortar composition may be hindered.

  Here, the “viscosity” of the material separation reducing agent means that a 2% aqueous solution of the material separation reducing agent is obtained by using a B-type viscometer (digital viscometer manufactured by BROOKFIELD: RVDV-1 +) with a rotor No. 4. A value measured at a rotational speed of 12 rpm and 20 ° C.

  Further, the Thixotropic Index (TI value) of the 2% aqueous solution of the material separation reducing agent at 20 ° C. is preferably 2.00 to 3.60, more preferably 2.20 to 3.40, and further preferably It is 2.40 to 3.20, and particularly preferably 2.60 to 3.00.

  When the TI value of the 2% aqueous solution of the material separation reducing agent at 20 ° C. is less than 2.00, the material separation resistance of the mortar composition is lowered, and sufficient shape retention cannot be obtained. Moreover, when the TI value of the 2% aqueous solution of the material separation reducing agent at 20 ° C. exceeds 3.60, the thixotropy is increased and the workability of the mortar composition may be hindered.

  Here, the “TI value” of the material separation reducing agent refers to a 2% aqueous solution of the material separation reducing agent in accordance with JIS K 5101-6-2: 2004, and a B-type viscometer (digital viscometer manufactured by BROOKFIELD) : RVDV-1 +). 4. The value measured at 20 ° C.

  The content of the material separation reducing agent is preferably 0.005 to 0.10 parts by mass, more preferably 0.01 to 0.08 parts by mass, further preferably 100 parts by mass of Portland cement. It is 0.015-0.06 mass part, Most preferably, it is 0.02-0.04 mass part.

  When the content of the material separation reducing agent is within the above range, it can be expected that sufficient shape retention is obtained while having good workability. When the content of the material separation reducing agent in the mortar composition is excessive, the viscosity of the mortar composition tends to increase, and the workability may be reduced.

  The cross-section repair material used in the method for repairing a concrete structure according to the present embodiment can be suitably added with an antifoaming agent, a setting modifier, and a shrinkage reducing agent as long as the characteristics of the present invention are not impaired.

  As the antifoaming agent, known substances such as synthetic substances such as silicone-based, alcohol-based, polyether-based and mineral oil-based or natural substances derived from plants can be suitably added. By adding an antifoaming agent, the surface properties and strength characteristics of the cross-sectional repair material are further improved.

  The setting modifier includes a setting accelerator that accelerates the hydration reaction and a setting retarder that delays the hydration reaction. Fine adjustment of the flowability, flow retention, and setting time of the cross-section repair material by appropriately selecting and adding each component (type), amount and ratio of the setting accelerator and setting retarder. Make sure.

  A known shrinkage reducing agent can be suitably added to the shrinkage reducing agent. As the shrinkage reducing agent, those having an alkylene oxide polymer in the skeleton of the chemical structure are preferable. For example, it is preferably selected from polyalkylene glycols such as polypropylene glycol and poly (propylene / ethylene) glycol, polyoxyalkylene ethers and generally known ones such as alkoxy poly (propylene / ethylene) glycol having 1 to 6 carbon atoms. Can be added. By adding a shrinkage reducing agent, the dimensional stability of the cross-sectional repair material is improved more reliably.

  The cross-section repair material used in the concrete structure repair method of the present embodiment can be suitably used for cross-section repair of a concrete structure. By using this cross-sectional repair material, it is possible to obtain a mortar composition that can be easily applied with a varnish or sprayed.

  The mortar composition used in the method for repairing a concrete structure according to this embodiment can be prepared by blending and kneading the above-mentioned cross-sectional repair material and water. An example of the mortar composition used in the present invention will be described below. This mortar composition can be suitably used for cross-sectional repair of concrete structures. When preparing a mortar composition, the flow value and unit volume mass of a mortar composition can be adjusted by changing the compounding quantity of water suitably. Thus, the mortar composition suitable for a use can be prepared by changing the compounding quantity of water. Here, the flow value is a value measured in accordance with the test method described in JIS R 5201: 1997 “Cement physical test method”, and the unit volume mass is JIS A 1171: 2000 “polymer cement”. It is a value (unit: kg / L) measured based on the test method described in “Testing method of mortar”.

  The amount of water is preferably 12 to 21 parts by mass, more preferably 13 to 20 parts by mass, still more preferably 14 to 19 parts by mass, and particularly preferably 100 parts by mass of the cross-sectional repair material. 15-18 parts by mass.

  The flow value at 20 ° C. of the mortar composition used in the method for repairing a concrete structure of the present embodiment is preferably 170 to 210 mm, more preferably 175 to 205 mm, and further preferably 180 to 200 mm. Especially preferably, it is 185-195 mm.

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

  The unit volume mass at 20 ° C. of the mortar composition used in the method for repairing a concrete structure of the present embodiment is preferably 1.50 to 2.50 kg / L, more preferably 2.00 to 2.40 kg / L. L, more preferably 2.10 to 2.30 kg / L, and particularly preferably 2.15 to 2.25 kg / L (liter).

  By setting the unit volume mass within the above range, while maintaining good workability of the mortar composition (good coatability and sprayability), it is possible to obtain an appropriate compressive strength for integration with a concrete structure. A mortar cured body having sufficient adhesiveness can be obtained.

  The mortar hardened | cured material formed with the repair method of the concrete structure of this embodiment can be obtained by hardening the above-mentioned mortar composition. An example of the obtained mortar cured body will be described below. The mortar hardened body can be suitably used for cross-sectional repair of a concrete structure. That is, the cured mortar formed by curing the mortar composition described above has an appropriate compressive strength and sufficient adhesiveness when integrated with a concrete structure.

The adhesive strength at the age of 28 days the mortar cured body obtained by method of repairing a concrete structure of the present embodiment is preferably 1.5 N / mm ² or more, more preferably be 1.7 N / mm ² or more , still more preferably 1.9 N / mm ² or more, and particularly preferably 2.0 N / mm ² or more.

  When the adhesive strength is not less than the above-mentioned value, the mortar cured body has sufficient adhesiveness when integrated with a concrete structure.

The mortar hardened body obtained by the method for repairing a concrete structure of the present embodiment has crack resistance that suppresses the occurrence of cracks even under outdoor construction environment conditions. Preferably, the number of cracks having a length of 30 cm or more is 0, the number of cracks having a length of 5 cm or more and less than 30 cm is 3 or less, and the number of cracks having a length of less than 5 cm is 6 or less per 1 m ² . More preferably, the number of cracks having a length of 30 cm or more is 0, the number of cracks having a length of 5 cm or more and less than 30 cm is 2 or less, and the number of cracks having a length of less than 5 cm is 4 or less per 1 m ² . More preferably, the number of cracks having a length of 30 cm or more is 0 per 1 m ² , the number of cracks having a length of 5 cm or more and less than 30 cm is 1 or less, and the number of cracks having a length of less than 5 cm is 2 or less. Particularly preferably, there are 0 cracks having a length of 30 cm or more, 1 crack having a length of 5 cm or more and less than 30 cm, and 0 cracks having a length of less than 5 cm per 1 m ² .

  When the number of cracks generated per unit area is not more than the above value, the mortar cured body has excellent crack resistance.

  The cross-section restoration material used in the method for repairing a concrete structure according to the present embodiment has a good compressibility when integrated with a good workability and concrete structure, and has sufficient adhesiveness and outdoor construction environment conditions. Also has excellent crack resistance.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment. For example, in this embodiment, since the deteriorated portion of the concrete structure has a rectangular parallelepiped shape, repair was performed by removing the deteriorated portion into a rectangular parallelepiped shape, but the shape of the portion to be removed according to the size and shape of the deteriorated portion May be different. Moreover, there may not be any reinforcing bars in the deteriorated part of the concrete structure.

  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.

(Experimental example 1)
[Materials used]
The raw materials shown in (1) to (8) below were prepared.
(1) Portland cement ・ Normal Portland cement (manufactured by Ube Mitsubishi Cement Co., Ltd., Blaine specific surface area = 3300 cm ² / g)
(2) Calcium carbonate fine powder-Cryolite powder (no particle having a particle size of 300 µm or more, mass ratio of particles having a particle size of 150 µm or more and less than 300 µm = 15.2 mass%, particle size of 75 µm or more And a mass ratio of particles of less than 150 μm = 35.6% by mass)
(3) Blast furnace slag ・ Blast furnace slag (manufactured by Chiba Riverment Co., Blaine specific surface area 4400 cm ² / g)
(4) Inorganic expansive material ・ Quicklime-gypsum expansive material (manufactured by Taiheiyo Materials Co., Ltd.)
(5) Fine aggregate ・ Silica sand (Table 1 shows the particle size composition of silica sand measured using a JIS sieve.)

(6) Antifoaming agent • Polyether type antifoaming agent (7) Fluidizing agent • Fluidizing agent A (polycarboxylic acid based fluidizing agent (property: powder type), manufactured by NOF Corporation, inorganic component (amorphous) Content of silica fine powder) = 56.3 mass%, chemical components of amorphous silica fine powder: SiO ₂ = 98.52 mass%, Al ₂ O ₃ = 0.54 mass%, in fluidizing agent A (The components other than the inorganic component were defined as active ingredients (43.7% by mass) contributing to fluidity.)
Fluidizing agent B (polyether / polycarboxylic acid based fluidizing agent (shape: powder type), manufactured by BASF Japan, content of inorganic component (crystalline inorganic powder) = 10.7% by mass, fluidizing agent Components other than the inorganic component in B were defined as active ingredients (89.3% by mass) contributing to fluidity.)
-Fluidizing agent C (polycarboxylic acid-based fluidizing agent (property: liquid type), manufactured by NOF Corporation, a liquid polycarboxylic acid-based material that does not have inorganic components (amorphous silica fine powder) in fluidizing agent A (The active ingredient contributing to the fluidizing agent and fluidity is 100% by mass.)

  The content of the amorphous silica fine powder of the fluidizing agent A and the content of the crystalline inorganic powder of the fluidizing agent B are each heat-treated in an electric furnace, and the content is obtained from the mass change before and after the heat treatment. It was. As heat treatment conditions, the temperature was raised from room temperature to 800 ° C. over 1 hour, held at 800 ° C. for 1 hour, and gradually cooled.

  FIG. 8 shows a powder X-ray diffraction pattern of the inorganic component (amorphous silica fine powder) contained in the fluidizing agent A. Since the diffraction pattern does not have a sharp peak and has only a gently curved base line 201, it was determined to be amorphous.

FIG. 9 shows a powder X-ray diffraction pattern of the inorganic component (crystalline inorganic powder) contained in the fluidizing agent B. The diffraction pattern had many sharp diffraction peaks 202 and had crystallinity. As a result of qualitative analysis, it was found that there are many proportions that coincide with the diffraction peaks of Pseudowollastonite and Ca ₃ (Si ₃ O ₉ ).

  Powder X-ray diffraction measurement uses a powder X-ray diffractometer RINT-2500 (manufactured by Rigaku Corporation), X-ray source is CuKα, tube voltage 35 kV, tube current 110 mA, measurement range 2θ = 5 to 50 °, Continuous Scanning mode. The diverging slit was 1 °, and the light receiving slit was 0.3 mm.

  The qualitative analysis of the powder X-ray diffraction diagram was performed using JADE 6.0 (manufactured by Materials Data Inc.), which is a powder X-ray diffraction pattern comprehensive analysis software.

  Chemical analysis of the amorphous silica fine powder contained in the fluidizing agent A was performed using a fluorescent X-ray analyzer ZSX100e (manufactured by Rigaku Corporation).

(8) Silica fume ・ Silica fume (Efaco, specific surface area 17 m ² / g)

(1) Portland cement, (2) calcium carbonate fine powder, (3) blast furnace slag, (4) inorganic expansion material, (5) fine aggregate, (6) antifoaming agent, (7) fluidizing agent, (8) No. 1 silica fume at the ratio shown in Table 2. 1 blends (No. 1-1 to No. 1-9) were prepared.

[Preparation of mortar composition]
No. 1 prepared with the blending ratio shown in Table 2. The amount of water shown in Table 3 was blended with each 100 parts by mass of 1 and kneaded to prepare a mortar composition of each 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%.

[Method for evaluating physical properties of mortar composition and cured mortar]
The prepared No. The flow value, unit volume mass, and adhesive strength of the mortar cured body of each mortar composition of 1 were measured. The measurement results were as shown in Table 3. Moreover, each measurement was performed by the method shown below.

(1) Measurement method of flow value The flow value was measured according to the test method described in JIS R 5201: 1997 "Physical test method of cement".
(2) Measurement method of unit volume mass Unit volume mass was measured based on the test method described in JIS A 1171: 2000 “Test method of polymer cement mortar”.
(3) Measuring method of adhesive strength In accordance with the test method described in JIS A 6916: 2000 “Preparation coating material for building”, the adhesion strength at 28 days of material age was measured and used as an index of adhesiveness. The ground conditions in the construction of the mortar composition were such that the surface of the base substrate was wetted with water (water moistening).

As shown in Table 3, no. 1-2-No. The mortar cured bodies of 1-4 and No1-9 were all 1.5 N / mm ² or more under the water dampening ground conditions, and sufficient adhesive strength was obtained. No. 1-2-No. The flow values of the mortar compositions of 1-4 and No1-9 were 189 to 194 mm. This result has shown that the cement composition of each reference example has the outstanding workability (good wiping property and spraying property).

  No. 1-2-No. The unit volume mass of the mortar composition of 1-4 and No1-9 was 2.19-2.25 kg / L. This result has shown that the mortar composition of each reference example has the outstanding workability (good coating property and sprayability).

No. No fluidizing agent. 1-1 has an adhesive strength of 1.0 N / mm ² . No. 1 containing fluidizing agent A prepared by replacing 1-3 calcium carbonate fine powder with blast furnace slag. The adhesive strength of 1-5 was 1.3 N / mm ² , and neither of them had sufficient adhesive strength. Also, the fluidizing agent B is No. No. 1 formulated according to the amount of the active ingredient of fluidizing agent A contained in 1-3. The adhesive strength of 1-6 was 1.2 N / mm ² , and sufficient adhesive strength was not obtained.

Furthermore, liquid fluidizing agent C which does not contain the inorganic component (amorphous silica fine powder) in fluidizing agent A and whose active ingredient has the same composition is No. No. 1 formulated according to the amount of the active ingredient of fluidizing agent A contained in 1-3. The adhesive strength of 1-7 is 0.7 N / mm ² . 1-7, no. No. 1 containing silica fume in accordance with the amount of the inorganic component (amorphous silica fine powder) in the fluidizing agent A contained in 1-3. The adhesive strength of 1-8 was 0.3 N / mm ² , and sufficient adhesive strength was not obtained in either case.

  From the result of the obtained adhesive strength, a polymer dispersion or a re-emulsified resin powder is used as a cross-section repair material by using a polycarboxylic acid-based fluidizing agent containing a specific amorphous silica fine powder and a calcium carbonate fine powder in combination. It was confirmed that sufficient adhesiveness can be obtained even without containing.

(Experimental example 2)
[Materials used]
The raw materials shown in (1) and (2) below were prepared.
(1) Thickener ・ Thickener A (manufactured by Matsumoto Yushi Co., Ltd., main component: hydroxypropylmethylcellulose, viscosity [20 ° C., 2% aqueous solution]: 250 mPa · s)
Thickener B (manufactured by Shin-Etsu Chemical Co., Ltd., main component: hydroxypropylmethylcellulose, viscosity [20 ° C., 2% aqueous solution]: 33 mPa · s)
(2) Material separation reducing agent Polymer synthetic copolymer (manufactured by BASF, trade name: Melvis F40, viscosity [20 ° C., 2% aqueous solution]: 4,283 mPa · s, TI value [20 ° C., 2% aqueous solution]: 2.76)

  No. in Table 2 1-3 was blended with (1) each thickener and / or (2) material separation reducing agent as shown in Table 4, respectively. 2-1. 2-6 was prepared and No. 2 in Table 2 was prepared. No. 1-9 was mixed with thickener A and a material separation reducing agent. 2-7 was prepared.

[Preparation of mortar composition]
No. 1 prepared at the blending ratio shown in Table 4. The amount of water shown in Table 5 was blended and kneaded with respect to 100 parts by mass of each of No. 2 to prepare mortar compositions of the respective formulations. The kneading was performed for 3 minutes outdoors (sunny) under the conditions of a temperature of 18 ° C., a relative humidity of 60%, and a wind speed of 0 m / s using a hand mixer with a rotational speed of 750 rpm.

[Method for evaluating physical properties of mortar composition and cured mortar]
First, the prepared mortar composition was applied to the wall surface with a scissors to evaluate workability. On the next day, the occurrence of cracks on the surface of the cured mortar body was evaluated. The physical properties were evaluated outdoors (sunny) under conditions of a temperature of 18 ° C., a relative humidity of 60%, and a wind speed of 5 m / s. The results are shown in Table 5.

(1) Evaluation method of workability The surface of a flexible board (wall surface) installed perpendicular to the floor surface is coated with a mortar composition to a thickness of 10 mm using a stainless steel rivet, and the mortar composition The coating workability was evaluated by four items, namely, flaw cutting, wrinkle feeding, wrinkle elongation, and wrinkle separation, and comprehensively judged in four stages: very good ◎, good ○, slightly bad Δ, and bad x.
(2) Method for evaluating crack resistance The day after the mortar composition was applied to the wall surface, the number of cracks generated per 1 m ^{2 of the} mortar cured body surface was classified into three categories (the crack length was less than 5 cm, 5 cm and 30 cm). Less than or equal to 30 cm or more), and comprehensively determined in four stages: very good ◎, good ◯, slightly bad Δ, and bad x.

  As shown in Table 5, under the outdoor construction environment conditions of Experimental Example 2, sufficient adhesiveness was obtained when integrated with a concrete structure. 1-3 and no. Each No. 1-9 based on 1-9. In all 2 formulations, the dredging workability was good or very good. Among the blends, the blend containing the material separation reducing agent is No. Very good results were shown except for 2-4.

  As for crack resistance, No. containing thickener A was used. 2-1 showed a good result. Furthermore, No. containing a thickener A and a material separation reducing agent. 2-6 and no. 2-7 showed very good results.

(Experimental example 3)
[Materials used]
The raw materials shown in (1) below were prepared.
(1) Water absorption adjusting agent Primer A (main component: styrene-acrylic acid alkyl ester copolymer, nonvolatile content 46.0%)
Primer B (main component: methacrylic acid alkyl ester-acrylic acid alkyl ester copolymer, nonvolatile content: 36.5%)
Primer C (main agent: epoxy resin, curing agent: modified polyamine, blending weight ratio: curing agent 50 with respect to main agent 100)

[Preparation of mortar composition]
No. 1 prepared at the blending ratio shown in Table 4. 2-6 and no. With respect to 100 parts by mass of 2-7, the amounts of water shown in Table 5 were respectively mixed 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%.

[Method for evaluating physical properties of cured mortar]
The prepared formulation No. For the mortar composition of No. 2-6, the adhesive strength under the base conditions (No. 3-1 to No. 3-4) shown in Table 6 was measured. Regarding the mortar composition of 2-7, the adhesive strength under the base conditions (No. 3-5) shown in Table 6 was measured. The measurement results were as shown in Table 6. Moreover, the measurement was performed by the method shown below.

(1) Measuring method of adhesive strength Based on the test method described in JIS A 6916: 2000 “Preparation coating material for construction”, the adhesive strength at 28 days of age was measured and used as an index of adhesiveness. The ground conditions for the construction of the mortar composition are: 1. The surface of the base substrate was moistened with water (water moistening). ^2. Apply a 5-fold diluted solution of primer A (mixing weight ratio: water 4 to primer A stock solution 1) at 200 g / m ² on the base substrate surface; 3. Apply a 3-fold dilution of primer B (mixing weight ratio: water 2 to primer B stock solution 1) at 150 g / m ² . The mortar composition was applied in a state where primer C (mixing weight ratio: 0.5 hardener relative to main agent 1) was applied at 150 g / m ² on the base substrate surface.

No. 1 which showed excellent crack resistance under the outdoor construction environment conditions of Experimental Example 2. The adhesive strength of the material age 28 of No. 2-6 is 1.5 N / mm ² or more in the water dampening ground condition (No. 3-1). Adequate adhesive strength was obtained as in 1-3. In addition, it was confirmed that the adhesion strength was further improved when the primer conditions were primer A (No. 3-2), primer B (No. 3-3) or primer C (No. 3-4). Furthermore, no. In the water fountain underlying conditions 3-1, the adhesive strength 2.6 N / mm ² at an age of 43 days, the adhesive strength 2.9 N / mm ² at an age of 79 days, confirmed to be improved over the age It was done.

No. 1 which showed excellent crack resistance under the outdoor construction environment conditions of Experimental Example 2. The adhesive strength of the material 2-8 on the 28th day is 1.5 N / mm ² or more in the primer condition of the primer C (No. 3-5). Adequate adhesive strength was obtained as in 1-9.

  From the above, No. having excellent workability and sufficient adhesiveness when integrated with a concrete structure. No. 1-3 based. As in 2-1, Portland cement, calcium carbonate fine powder, inorganic expansion material, fine aggregate, polycarboxylic acid-based fluidizing agent containing 20-80% by mass of a specific amorphous silica fine powder, and a specific viscosity It was confirmed that the use of the cross-sectional restoration material containing the cellulosic thickener possessed has excellent workability even under outdoor construction environment conditions and excellent crack resistance. Furthermore, by adding a specific material separation reducing agent, workability and crack resistance are improved even under outdoor construction environment conditions while having sufficient adhesion when integrated with a concrete structure. Was confirmed. That is, the cross-sectional repair material of the present embodiment can be suitably used for repairing a concrete structure without including a polymer dispersion, a re-emulsifying resin powder and / or a fiber, Work can be done easily.

  DESCRIPTION OF SYMBOLS 11, 12 ... Concrete part, 13, 15 ... Rebar, 14 ... Area | region, 16 ... Rust prevention material, 17 ... Primer layer, 18 ... Mortar composition, 20 ... Concrete structure, 21 ... Mixer, 22 ... Mortar pump, 23 DESCRIPTION OF SYMBOLS ... Air source, 24 ... Pressure hose, 25 ... Spray gun, 100, 101, 102, 103, 104, 105 ... Concrete structure, 201 ... Base line of gentle curve, 202 ... Sharp diffraction peak.

Claims (6)

A mortar construction process for constructing a mortar composition prepared by mixing and kneading a cross-section repair material and water at a location where a part of the concrete structure has been removed,
Curing the mortar composition and forming a mortar cured body at the location, and a method for repairing the concrete structure,
The cross-sectional repair material includes Portland cement, calcium carbonate fine powder, inorganic expansion material, fine aggregate, fluidizing agent and cellulosic thickener,
Containing 0.01 to 0.3 parts by mass of the fluidizing agent with respect to 100 parts by mass of the Portland cement;
The fluidizing agent includes a polycarboxylic acid copolymer and amorphous silica fine powder,
20 to 80 mass% of the amorphous silica fine powder is contained in the fluidizing agent,
The cellulosic thickener is a method for repairing a concrete structure, wherein the viscosity of a 2% aqueous solution at 20 ° C. is 150 to 2000 mPa · s. The fine aggregate has a particle size of 600 μm or more and a particle mass ratio of less than 1180 μm of 10 to 45% by mass,
The method for repairing a concrete structure according to claim 1, wherein the mass ratio of particles having a particle diameter of 150 µm or more and less than 300 µm is 1 to 15 mass%. The cross-sectional restorative material, to Portland cement 100 parts by weight of 10 to 50 parts by weight of calcium carbonate fine powder, the inorganic expandable materials 5-15 parts by weight, fine aggregate 100-185 parts by 及 beauty cellulosic thickener 0. The repair method of the concrete structure of Claim 1 or Claim 2 containing 01-0.20 mass part.   The calcium carbonate fine powder does not include particles having a particle size of 300 μm or more, a particle size of 150 μm or more and a mass ratio of particles of less than 300 μm is less than 20% by mass, a particle size of 75 μm or more, and The mass ratio of particles that are less than 150 μm is 10 to 50 mass%.
The repair method of the concrete structure of any one of Claims 1-3.   The inorganic expansion material is quicklime-gypsum expansion material,
The repair method of the concrete structure of any one of Claims 1-4. The method for repairing a concrete structure according to any one of claims 1 to 5 , wherein the cross-sectional restoration material further includes a material separation reducing agent, and the material separation reducing agent is a polymer synthetic copolymer.

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