JP2013203561A - Water stop material, and method of forming water stop portion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water stop material capable of imparting excellent water stop performance to a portion which may easily cause water leak in concrete.SOLUTION: A water stop material includes portland cement, a cement crystal proliferating agent including a cement component, a calcium carbonate powder, a high performance water reducing agent and/or high performance AE water reducing agent, and water, wherein the content of water to the 100 pts.mass total of the portland cement, the cement component and the calcium carbonate is ≥15 pts.mass.

Description

  The present invention relates to a water-stopping material and a method for forming a water-stopping part that forms a water-stopping part in concrete.

  In the construction of a concrete structure, so-called jointing, in which concrete is placed several times, is performed due to construction reasons such as the amount of placement per time and the assembly procedure of the support. For example, a horizontal seam may be formed between the bottom plate portion or the top plate portion and the wall portion or in the middle of the wall portion. In this case, since the upper concrete (upper lift) is placed on the hardened lower concrete (lower lift), the interface is likely to be fragile due to latency or dust left on the upper surface of the lower lift, and the water channel Tended to cause water leakage.

  Therefore, in order to eliminate such inconvenience, a method is known in which a predetermined treatment is performed on the joining surface when concrete is cast. For example, the following Patent Document 1 discloses a mortar composition for concrete casting made of a composition comprising a cement, a pozzolanic fine powder containing a silica compound, fine aggregate, water, and a water reducing agent. It is shown that durability and watertightness can be secured at the joint by placing this on the joint surface.

JP 2001-322857 A

  In concrete structures, it is desirable to reduce water leakage as much as possible. However, in the case where water is prone to inundation, such as when applied to underground structures, the conventional method as described above is applied. However, there were cases where water leakage could not be prevented sufficiently.

  Therefore, the present invention has been made in view of such circumstances, and a water-stopping material capable of imparting excellent water-stopping to a portion that is likely to cause water leakage in concrete, and a method for forming a water-stopping portion using the same. The purpose is to provide.

  In order to achieve the above object, the water-stop material of the present invention includes Portland cement, a cement crystal growth agent containing a cement component, calcium carbonate powder, a high-performance water reducing agent and / or a high-performance AE water reducing agent, water, And the content of water with respect to 100 parts by mass in total of Portland cement, cement component and calcium carbonate is 15 parts by mass or more.

  For example, after applying the water stop material of the present invention to the joint surface of the lower lift, by performing the joint to cast the concrete for the upper lift, the water stop portion made of the water stop material ( Water stop layer) is formed. Since such a water-stopping layer is formed from a water-stopping material containing Portland cement and a cement crystal growth agent, when water invades at the joint, water that has invaded by the action of the cement crystal growth agent. And the unhydrated cement component can be reacted to form a hydrated product, thereby inhibiting flooding.

  In addition, since the unhydrated cement component usually remains in the hardened concrete, for example, even if a cement crystal growth agent is added to the joint, the same reaction as described above at the time of flooding May be possible. However, as a result of studies by the present inventors, the cement crystal growth agent alone has a weak adhesion to the joint surface of the lower lift, so that the reinforcing bars and formwork performed before drying after application and the placement of the upper lift are performed. It was confirmed that there was a tendency to peel off during construction. Further, it was also found that the water-stop part formed only from the cement crystal growth agent has a strength lower than that of the concrete, which may cause the joint to become brittle. Furthermore, when cement crystal growth agent is mixed with water for application, it reacts with water immediately after it is added to cause pseudo-condensation reaction, resulting in a lump of powder. In some cases, the workability deteriorated.

  On the other hand, since the water-stopping material of the present invention contains Portland cement, it can form a water-stopping layer that has high adhesion to concrete and is difficult to peel off. Since the water-stopping layer obtained in this way has a small difference in strength from concrete, the strength of the joint can be sufficiently increased. In addition, since the water-stopping material contains a high-performance water reducing agent, the reaction of the cement crystal growth agent does not proceed rapidly even if it contains water, so that the workability by coating or the like is good.

  Furthermore, according to the water-stopping material of the present invention, since it contains Portland cement, a large amount of unhydrated cement components can be present in the vicinity of the water-stopping layer. In particular, it is easier to produce a hydrated product. As a result, it is possible to form a water stop layer that can exhibit extremely excellent water stop.

  In addition, since the water-stopping material of the present invention contains calcium carbonate powder, the components in Portland cement and cement crystal growth agent are uniformly dispersed, and calcium is the core of the hydrated product. As a result, a water-stopping layer having a denser structure can be formed. In addition, the high-performance water-reducing agent or high-performance AE water-reducing agent can further suppress the progress of pseudo-coagulation as described above, and can better disperse Portland cement and cement crystal growth agent together with calcium carbonate powder. Can contribute to the formation of a water-stopping layer that can exhibit excellent water-stopping properties.

  The water-stopping material of the present invention preferably has a water content of 25 parts by mass or more based on a total of 100 parts by mass of Portland cement, cement components and calcium carbonate. This makes it easier to obtain the above-described effects.

  Moreover, this invention provides the formation method of the water stop site | part which apply | coats the water stop material of the said invention on the surface of the hardened concrete, and forms a water stop site | part. For example, after applying a water-stopping material to the joint surface of the lower lift made of hardened concrete, a water-stopping part (water-stopping layer) can be formed at the joint by applying the upper lift. it can. In such a method, since the water-stopping material of the present invention is used, good workability is obtained, and a water-stopping layer that has a dense structure and can exhibit excellent water-stopping is surely obtained. Can be formed.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the water stop material which can provide the outstanding water stop to the site | part which becomes a cause of the water leak in concrete, and the formation method of the water stop site | part using this.

It is a schematic diagram which shows the cross-sectional structure of the vicinity of the joint in a concrete structure. It is a schematic diagram which shows the cross-sectional structure of the vicinity of the joint in a concrete structure. It is a schematic diagram which shows the cross-sectional structure of the vicinity of the joint in a concrete structure.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings as necessary.

[Waterproof material]
A water-stop material according to a preferred embodiment includes Portland cement, a cement crystal growth agent containing a cement component, calcium carbonate powder, a high-performance water reducing agent or a high-performance AE water reducing agent, and water. Water content with respect to a total of 100 parts by mass of the cement component and calcium carbonate is 15 parts by mass or more. Such a water-stop material is applied to, for example, a joint surface of concrete to be used for forming a water-stop portion (water-stop layer). Hereinafter, the components of the water stop material will be described.

  First, as Portland cement, normal Portland cement, early strength Portland cement, super early strength Portland cement, medium heat Portland cement, low heat Portland cement, sulfate-resistant Portland cement, etc. can be applied. Applicable. From the viewpoint of improving the adhesion to concrete and reducing the difference in strength from concrete, it is preferable to select the same cement component as that in the concrete constituting the frame of the concrete structure.

  Cement crystal growth agents are materials that can penetrate into concrete to produce cement crystals or equivalent crystals. Examples thereof include Portland cement (particularly ordinary Portland cement), a component containing silica sand and a catalytic compound, and those disclosed in Japanese Patent No. 1815985 can be applied. As such a cement crystal growth agent, Zypex (registered trademark, manufactured by Japan Zypex Corporation) can be applied. In particular, Zypex Concentrate is preferable from the viewpoint of obtaining good water stopping properties.

The calcium carbonate powder is a powder composed of calcium carbonate (CaCO ₃ ), and for example, limestone fine powder can be applied. The limestone fine powder may contain a small amount of components other than calcium carbonate, but most of it is composed of calcium carbonate, so the amount of calcium carbonate powder added can be directly applied as the amount of limestone fine powder added. Also good.

  As the high-performance water-reducing agent or the high-performance AE water-reducing agent, a high-performance water-reducing agent or a high-performance AE water-reducing agent used as an admixture for concrete can be applied without particular limitation. In addition, the water stop material may contain any one of a high performance water reducing agent and a high performance AE water reducing agent, and may contain both in combination.

  In the water-stop material containing each component described above, the water content with respect to a total of 100 parts by mass of Portland cement, the cement component contained in the cement crystal growth agent, and calcium carbonate is 15 parts by mass or more, and 25% by mass. The above is preferable. The more suitable the water content, the better the dispersibility of each component in the water-stopping material, the better workability is obtained, and the dense structure has excellent water-stopping properties. It becomes possible to form a water stop part. However, if the water content is too high, the fluidity becomes too high, the strength is lowered, and the unhydrated cement is reduced, so that the workability and the hardenability may be lowered. Therefore, the content of the water is preferably 35% by mass or less.

  The water-stopping material is one in which each component is blended so that at least the above-mentioned water content condition is satisfied, but it is more preferable that each component is contained in the following blending ratio.

  That is, first, the content of Portland cement is preferably 10 to 70 parts by mass and more preferably 45 to 70 parts by mass with respect to 100 parts by mass of the cement crystal growth agent. By containing Portland cement at such a ratio, the water stoppage and strength of the water stop portion (water stop layer) formed from the water stop material can be improved.

  The content of the calcium carbonate powder is preferably 5 to 60 parts by mass and more preferably 5 to 20 parts by mass with respect to 100 parts by mass of the cement crystal growth agent. The more suitable the content of the calcium carbonate powder is, the more dense the water-stopping portion that is excellent in water-stopping can be formed.

  In particular, in the water-stopping material, the total content of Portland cement and calcium carbonate powder is preferably 50 to 70 parts by mass and more preferably 60 to 70 parts by mass with respect to 100 parts by mass of the cement crystal growth agent. preferable. By setting the total content of Portland cement and calcium carbonate powder in such a range, it becomes easy to form a water-stopping portion that is dense and excellent in water-stopping properties while obtaining good workability. Within such a range that satisfies the condition of the total content, even if the content of Portland cement is increased or decreased in accordance with desired characteristics, sufficient workability and water-stopping tend to be obtained.

  Moreover, it is preferable that content of a high performance water reducing agent or a high performance AE water reducing agent is 0.3-2.0 mass% with respect to a total of 100 mass parts of Portland cement, a cement crystal growth agent, and calcium carbonate. In the case where both the high-performance water reducing agent and the high-performance AE water reducing agent are included, the total of them may be made to satisfy this content. As a result, the effect of inhibiting pseudo-aggregation is obtained particularly well and excellent workability is obtained, and in addition, the dispersibility of Portland cement and cement crystal growth agent is extremely good, and it is a dense and excellent water-stopping property. A water site can be formed.

  The water-stop material of the present embodiment contains Portland cement, cement crystal growth agent, calcium carbonate powder, high-performance water reducing agent and / or high-performance AE water reducing agent, and water under the conditions described above. As another component, you may further contain the component known as an admixture material of concrete, for example. Examples of other components include blast furnace slag fine powder, silica fume, fly ash, and the like. These components can be contained in an amount of, for example, about 5 to 20 parts by mass with respect to a total of 100 parts by mass of Portland cement, cement crystal growth agent and calcium carbonate.

[Method for forming water-stop site]
Drawing 1 is a mimetic diagram showing the section composition near the joint in a concrete structure, and is the figure showing the structure near the joint formed by the formation method of the water stop part concerning a 1st embodiment. A concrete structure 100 shown in FIG. 1 has a structure in which an upper lift 20 is spliced on a lower lift 10, and a horizontal joint 80 exists between the lower lift 10 and the upper lift 20. It has become. The horizontal seam 80 is provided with a water blocking layer 30.

  The formation method of the water stop site | part of this embodiment is a method of forming a water stop site | part (water stop layer) at the horizontal joint of concrete. In this method, first, a paste-like water-stopping material is prepared by mixing the components of the water-stopping material in the proportions described above.

  Next, after applying the paste-like water stop material obtained above to the upper surface (horizontal joint surface) of the lower lift 10 made of hardened concrete in which the vertical reinforcing bars 40 are arranged, if necessary, And dried to form the water blocking layer 30. The application of the water-stopping material can be performed, for example, by supplying a paste of the water-stopping material to the horizontal joint surface using a brush or a brush.

  In this embodiment, the water stop material is applied so that two rows of water stop layers 30 are formed in parallel on the horizontal joint surface of the lower lift 10. The water blocking layer 30 is preferably provided so as to intersect, preferably orthogonally cross, the direction in which water enters. For example, when the concrete structure 100 is a part constituting a wall part of a building, the water blocking layer 30 has a thickness of the wall part in order to prevent water from entering from the outside to the inside of the wall part. It is preferable to provide it so as to be orthogonal to the vertical direction.

  The width of the water blocking layer 30 is preferably 10% or more, and preferably 20% or more with respect to the width of the concrete structure 100 (distance in the direction perpendicular to the water blocking layer 30 in the concrete structure 100). It is more preferable. When providing a plurality of rows of water blocking layers 30 as in the present embodiment, the sum of their widths may satisfy this condition. The water stop layer 30 may be formed on the entire horizontal joint surface of the lower lift 10, but from the viewpoint of workability and cost, the width of the water stop layer 30 is the width of the concrete structure 100. Is preferably 30% or less. Even with such a width, it is possible to obtain sufficient adhesion to the horizontal joint surface and sufficient water stoppage.

  After the water blocking layer 30 is formed on the horizontal joint surface of the lower lift 10, the concrete is further placed on the lower lift 10 and hardened, whereby the upper lift 20 with the vertical reinforcing bars 40 disposed therein is provided. Form. As a result, a concrete structure 100 in which two rows of water blocking layers 30 are formed near the horizontal joint 80 is constructed.

  In the concrete structure 100 having such a structure, the water stop layer 30 is usually provided at the horizontal joint 80 where the structure is likely to be brittle. Then, it comes into contact with the water blocking layer 30. When the invaded water comes into contact with the water-stopping layer 30, the Portland cement contained in the water-stopping layer 30 and the unhydrated cement component remaining in the vicinity of the water-stopping layer 30 are used as cement crystal growth agents in the water-stopping layer 30. It reacts with water by the action of to produce a hydrated product. As a result, further intrusion of water is suppressed, and at the same time, a site that prevents infiltration of water by the formation of the hydrated product is formed. As a result, the concrete structure 100 is very unlikely to cause water intrusion at the horizontal joint 80.

  Drawing 2 is a mimetic diagram showing the section composition near the joint in a concrete structure, and is the figure showing the structure near the joint formed by the formation method of the water stop part concerning a 2nd embodiment.

  A concrete structure 200 shown in FIG. 2 has a structure in which a water stop plate 50 is further provided in addition to the configuration of the concrete structure 100 shown in FIG. The water stop plate 50 is provided in the vicinity of the center of the concrete structure 100 in the width direction so that the width direction intersects (orthogonally) the horizontal joint 80. The two rows of water stop layers 30 are provided on both sides of the water stop plate 50 so as to be parallel to the water stop plate 50.

  In the manufacture of the concrete structure 200, for example, when the lower lift 10 is constructed, the water stop plate 50 is embedded in the concrete of the lower lift 10 with about half of the width direction, and the remaining half is the horizontal transfer surface. It arrange | positions so that it may protrude upwards. Then, the water stop layer 30 is formed on both sides of the water stop plate 50 by the same method as described above. Thereafter, a concrete structure 200 having a structure as shown in FIG. 2 is obtained by driving the upper lift 20.

  According to the concrete structure 200 having such a structure, in addition to the water stop effect due to the formation of the hydrated product in the water stop layer 30, the physical water stop effect of blocking water intrusion in the water stop plate 50. Can also be obtained. Therefore, the water-stopping effect of both the water-stopping layer 30 and the water-stopping plate 50 makes it possible to obtain a further excellent water-stopping property.

  In the production of the concrete structure 200, the water stop plate 50 having a surface applied with a water stop material may be used. In that case, the concrete structure 200 has a structure in which the water blocking layer 30 is also formed on the surface of the water blocking plate 50. In the case of having such a structure, in the water stop plate 50, in addition to the effect of the water stop plate 50 itself blocking water, the water stop layer 30 on the surface of the water stop plate 50 forms a hydrated product. Since the water-stopping effect is exhibited, a further excellent water-stopping property can be obtained.

  Drawing 3 is a mimetic diagram showing the section composition near the joint in a concrete structure, and is the figure showing the structure near the joint formed by the formation method of the water stop part concerning a 3rd embodiment.

  The concrete structure 300 shown in FIG. 3 has a single row of water-stopping layers 30 formed at the horizontal joint 80 between the lower lift 10 and the upper lift 20 in which the vertical reinforcing bars 40 are arranged, The concrete structure 300 has a structure in which a surface water blocking layer 32 is provided on the outer surface. The surface water blocking layer 32 is provided on the outer surface of the concrete structure 300 so as to close the joint 80 from the outside. A waterproof layer 60 is further formed on the outer surface of the surface water blocking layer 32.

  As described above, the water-stopping material according to the embodiment of the present invention is used for forming a water-stopping portion (water-stopping layer) at the horizontal joint as exemplified above, for example, covering the surface. It is applicable also to the use which forms a water stop part (water stop layer).

  In the construction of the concrete structure having the above structure, the horizontal joint 80 is covered from the outside after forming up to the upper lift 20 in the same manner as the concrete structure 100 except that the water blocking layer 30 is arranged in a row. Thus, the surface water-stopping layer 32 is formed by applying the water-stopping material and drying it as necessary. Thereafter, the waterproof layer 60 is formed by further applying a normal waterproofing process such as applying an acrylic resin mortar so as to cover the surface waterproofing layer 32.

  According to the concrete structure 300 having such a structure, first, the waterproof layer 60 and the surface water blocking layer 32 make it difficult for water to enter the horizontal joint 80 from the outside. In particular, the surface water-stopping layer 32 can exhibit an excellent water-stopping effect by inhibiting the intrusion of water by the formation reaction of the hydrated product. Even if water enters the horizontal joint 80, further water intrusion is suppressed in the water blocking layer 30. As a result, the concrete structure 300 has a high water-stopping property.

  As mentioned above, although the formation method of the water stop part (water stop layer) which concerns on suitable embodiment, and the concrete structure in which the water stop structure was formed by it was demonstrated, this invention is not necessarily limited to embodiment mentioned above. It is not a thing.

  For example, the number of the water-stopping layers 30 formed on the horizontal joint 80 is not necessarily limited to the number of the above-described embodiments (one or two rows), and may be appropriately increased or decreased according to the required water-stopping property. it can. Moreover, the position where the water blocking layer 30 is formed is not limited to the position of the above-described embodiment, and can be an arbitrary position of the horizontal joint. Furthermore, the water stop plate 50, the surface water stop layer 32, and the like can be provided in any combination. For example, when high water stopping is required, both of them may be provided in combination. Furthermore, the formation of the water-stopping part (water-stopping layer) by application of the water-stopping material of the present invention is not limited to the horizontal seam as shown in the above-described embodiment and the surface covering it. As long as it is a part that can penetrate, it can be applied without particular limitation.

  EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited to a following example.

  Portland cement, cement crystal growth agent (Zypex Concentrate (Japan Zypex)), limestone fine powder, high-performance water reducing agent, and water were mixed to prepare a paste-like waterstop material. Is 0.35 in water, 0.5 in Portland cement, 0.2 in limestone fine powder, and the content of the high-performance water reducing agent in Portland cement, cement It adjusted so that it might become 1.5 mass% with respect to the total mass of a crystal growth agent and a limestone fine powder.

  The above water-stopping material is applied to the upper surface (horizontal joint surface) of the lower lift made of concrete using a brush, and then cured, in a direction perpendicular to the width direction of the lower lift. An extending row of water blocking layers was formed. At this time, the width of the water blocking layer was 10 cm.

  After that, the concrete was cast on the lower lift on which the water blocking layer was formed and cured to form an upper lift, and a concrete structure having a structure in which the upper lift was cast on the lower lift was constructed. . As a result of evaluating the concrete structure thus obtained, it was confirmed that the water-stopping layer has high adhesion to the lower lift and has excellent water-stopping performance. .

  DESCRIPTION OF SYMBOLS 10 ... Lower lift, 20 ... Upper lift, 30 ... Water stop layer, 32 ... Surface water stop layer, 40 ... Vertical reinforcing bar, 50 ... Water stop plate, 60 ... Waterproof layer, 80 ... Horizontal joint, 100, 200, 300 ... concrete structure.

Claims (3)

Portland cement, cement crystal growth agent containing a cement component, calcium carbonate powder, high-performance water reducing agent and / or high-performance AE water reducing agent, and water,
A water-stopping material, wherein the content of water with respect to 100 parts by mass in total of the Portland cement, the cement component and calcium carbonate is 15 parts by mass or more.   The water-stopping material according to claim 1, wherein the content of water with respect to 100 parts by mass in total of the Portland cement, the cement component and calcium carbonate is 25 parts by mass or more.   A method for forming a water-stopping part, comprising applying a water-stopping material according to claim 1 or 2 to a surface of cured concrete to form a water-stopping part.

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