JP6345641B2 - Water stop agent - Google Patents

Description

  The present invention relates to a water-stopping agent capable of stopping water leakage from a crack generated in a concrete structure such as a dam body or a river slope.

  When a crack occurs in a concrete structure such as a dam body or river embankment, water leakage may occur from the crack. And a sandbag is installed in the crack which the water leaked, and a water leak is stopped by inject | pouring a water-stopping agent.

  Conventional water-stopping agents are made of cement milk, water glass or the like. When stopping water leakage from a crack generated in a concrete structure, a water-stopping agent is injected into the crack, and cement milk and water glass are instantaneously aggregated. Stop clogging by clogging.

  In addition, since water leakage from cracks in concrete structures is high in water pressure, the water-stopping agent can contain a soft material or water-swellable fiber, Was prevented from being washed away by water pressure, and the initial water resistance was increased, thereby preventing water leakage (see, for example, Patent Documents 1 and 2).

JP 2002-047630 A JP 07-229136 A

  However, with a water-stopping agent mixed with a soft material, the soft material consists of a piece of cloth and is lighter than cement milk, so it is easy to separate the soft material from the water-stopping agent. When using a mortar pump that sends out the agent, the mortar pump may be clogged by the separated soft material, and therefore, the workability during use may be inferior.

  In addition, in the water-stopping agent mixed with water-swellable fibers, the water-swellable fiber is a water-absorbing polymer, so water is absorbed instantly and the usable time as a water-stopping agent is short. Workability may be inferior.

  This invention solves the above-mentioned subject, and can provide the water stop agent which can stop the water leak from the crack which generate | occur | produces in a concrete structure, and can improve workability | operativity at the time of use. Objective.

  The water-stopping agent according to the present invention is a water-stopping agent containing cement, aggregate containing slag aggregate, and water, and S / C (volume ratio of aggregate / cement) is 3 to 5. .5, and the volume content of the slag aggregate in the aggregate is 50 to 90%, and the slag aggregate is a test sieve—Part 1: Metal mesh sieve (JIS Z 8801-1: 2006). The sieve has a particle size of passing through 90% by mass or more of a sieve having a nominal aperture of 4.75 mm.

  In the water-stopping agent of the present invention, since the S / C is 3 to 5.5, the aggregate and the cement can be closely packed, and the viscosity of the water-stopper is the machine of the cement The water-stopping agent has excellent mortar pump stability. Moreover, in the water stopping agent of this invention, the volume content rate of the slag aggregate in an aggregate is 50 to 90%. Slag aggregate has a slow water-curing property compared with cement. Thereby, the water-stopping agent of this invention can ensure a pot life, while having high sclerosis | hardenability. In addition, the slag aggregate is an aggregate that is a constituent of a water-stopping agent because it has a particle size that passes 90% by mass or more of a sieve having a nominal opening of 4.75 mm as defined in JIS Z8801-1: 2006. The particles are fine. That is, the waterstop agent can penetrate into fine cracks generated in the concrete structure.

  Therefore, with the water-stopping agent of the present invention, it is possible to stop water leakage from cracks occurring in the concrete structure, and workability during use can be improved.

  In the water-stopping agent of the present invention, the slag aggregate is preferably an electric furnace oxidation slag aggregate. Since the electric furnace oxidation slag aggregate is a slag aggregate with excellent corrosion resistance, the water-stopping agent using the electric furnace oxidation slag aggregate has excellent corrosion resistance, that is, excellent durability. .

  Moreover, in the water-stopper of this invention, it is preferable that the flow value prescribed | regulated to "the physical test method of a cement (JISR5201: 2015) 12 flow test" is 200-300 mm. This is because the water-stopping agent has fluidity without separation of the aggregate and has excellent workability.

It is a conceptual longitudinal cross-sectional view which shows embodiment of the leak prevention construction of a concrete structure using the water stop agent which is one Embodiment of this invention. It is the schematic of the kneading | mixing process of the water stop agent which is one Embodiment of this invention.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the embodiment, as shown in FIG. 1, a description will be given by taking as an example water stoppage to water leakage caused by a crack generated in a dam body 31. Of course, the present invention is not limited to the use of water stoppage to the dam body 31 and is used for water stoppage of all concrete structures such as river levee surface slopes, irrigation channels, water storage tanks and swimming pools. Can be applied.

  As shown in FIG. 2, the water-stopping agent 11 of the embodiment is mixed by kneading the powder part 13 and the liquid part 15 using a mortar mixer 21.

  The powder part 13 is comprised from cement, the slag aggregate as an aggregate, and quartz sand. Moreover, the powder part 13 may contain a thickener or a water reducing agent.

  The slag aggregate is an aggregate obtained by processing slag as a by-product generated in a steel blast furnace or converter, and an electric furnace oxidation slag aggregate defined in an electric furnace oxidation slag aggregate (JIS A 5011-4: 2013). It can be preferably used. By using the slag aggregate, the water-stopping agent 11 has a high compressive strength due to the water-curing property of the slag aggregate, and has excellent adhesion to a concrete structure. It will be a thing. Moreover, since the slag aggregate has a slower water-curing property than cement, the water-stopping agent 11 can ensure a pot life. And since the electric furnace oxidation slag aggregate is a slag aggregate excellent in corrosion resistance, the water-stopping agent 11 using the electric furnace oxidation slag aggregate is excellent in corrosion resistance, that is, excellent in durability. It will be a thing. It should be noted that other slag aggregates can be used for the water-stopping agent 11 within a range that does not impair the effects of the present invention. Other slag aggregates include blast furnace slag aggregate (JIS A 5011-1: 2013), ferronickel slag aggregate (JIS A 501-2: 2003), and copper slag aggregate (JIS A 5011-3: 2003). Etc.

  The slag aggregate has a particle size that passes 90% by mass or more of a sieve having a nominal aperture of 4.75 mm as specified in a test sieve-Part 1: Metal mesh sieve (JIS Z 8801-1: 2006). (5 mm electric furnace oxidation slag fine aggregate) is preferred. Aggregate particles which are constituent elements of the water-stopping agent 11 become fine, and the water-stopping agent 11 can penetrate into fine cracks generated in the concrete structure and can stop water leakage from the cracks. It is. The particle size of the slag aggregate is more preferably a particle size that passes through a 2.36 mm sieve by 85 mass% or more (2.5 mm electric furnace oxidized slag fine aggregate), and most preferably 1 It is a particle size (1.2 mm electric furnace oxidation slag fine aggregate) that passes 80 mass% or more through a 18 mm sieve.

  In the water-stopping agent 11 of the present invention, an aggregate other than the slag aggregate is used as an aggregate in a range of 10 to 50% in volume content with respect to the entire aggregate. As the aggregate other than the slag aggregate, silica sand, calcium carbonate powder, cerven (ceramics pulverized product) and the like can be used.

  Cement is a material that hardens when combined with water, and ordinary Portland cement defined in Portland cement (JIS R 5210-2009) can be suitably used. In addition, the waterstop agent 11 can also use another cement within the range which does not inhibit the effect of this invention. As other cements, early-strength cement, slag cement, fly ash cement, gypsum and the like can be used.

  The water-stopping agent 11 of the present invention has an S / C of 3 to 5.5. As a result, the aggregate and the cement can be closely packed, and the viscosity of the water-stopping agent 11 has a viscosity excellent in mechanical stability of the cement. The water-stopping agent 11 is a mortar pump. It is excellent in stability. In addition, since the water-stopping agent 11 contains an appropriate amount of aggregate, bubbles contained in the water-stopping agent 11 can stably exist, and the water-stopping agent 11 has an excellent density change rate described later. It will be a thing. More preferably, it is 3.5-5.0, Most preferably, it is 4.0-4.5.

  Moreover, the water-stopping agent 11 of the present invention has a volume content of slag aggregate in the aggregate of 50 to 90%. Slag aggregate has a slow water-curing property compared with cement. Thereby, the water stop agent 11 of this invention can ensure a pot life, while having high sclerosis | hardenability. Moreover, although slag aggregate has water-hardening property, it is not highly miscible with air, and if the volume content of the slag aggregate in the aggregate is too high, the density change rate will be inferior as workability. . More preferably, it is 60 to 80%, and most preferably 70 to 75%.

  The thickener is an additive added for the purpose of preventing sedimentation of the aggregate of the water-stopping agent 11 or for the purpose of improving the fluidity of the water-stopping agent 11. As the thickener, one or more of bentonite, methylcellulose, hydroxyethylcellulose, urethane, acrylic and the like can be used. Among these, bentonite-based, methylcellulose-based, and hydroxyethylcellulose-based materials are powdery in the form of raw materials, and are excellent in dispersibility in the powder part 13, and therefore can be used more preferably. In addition, since urethane type and acrylic type are liquids in the form of raw materials, they can be used by being dispersed in the liquid part 15.

  The water reducing agent is an additive added to increase the strength of the water stopping agent 11 such as the compressive strength by reducing the amount of water added to the water stopping agent 11. Water reducing agents include polyalkylallyl sulfonate condensate, melamine sulfonate condensate, lignin sulfonate condensate, naphthalene sulfonate condensate, polycarboxylic acid, oxycarboxylic One or more of acid salts and aminosulfonic acids can be used. If the form of the water reducing agent is powdery, it is excellent in dispersibility in the powder part 13 and can be used more preferably.

  The liquid part 15 is mainly composed of water such as tap water, and may contain a synthetic resin emulsion and other additives described later, if necessary. Water hardens the cement contained in the water-stopping agent 11 and imparts fluidity to the water-stopping agent 11. It is preferable to use fresh water such as tap water instead of seawater in order to prevent the occurrence of alkali-aggregate reaction and decrease in strength caused by salt.

  The synthetic resin emulsion is a resin dispersion capable of forming a resin film and reinforces the binding of the water-stopping agent 11. The resin film has flexibility, and the water-stopping agent 11 becomes flexible by adding a synthetic resin emulsion, and can absorb vibrations received by the concrete structure. .

  As shown in FIG. 2, the waterstop agent 11 of the embodiment is mixed by kneading the powder part 13 and the liquid part 15 using a mortar mixer 21. Specifically, after injecting the liquid part 15 into the mortar mixer 21, the operation of the mortar mixer is started at a rotational speed at which the liquid part 15 does not foam, and mamako (the mass of the powder part 13 not dispersed in the liquid part 15) The powder part 13 is charged in a plurality of times so as not to occur. And the viscosity adjustment water is added so that the flow value prescribed | regulated to the "physical test method (JISR5201: 2015) 12 flow test" of the water stopping agent 11 may be set to 200-300 mm. When the flow value is 200 to 300 mm, the water-stopping agent 11 has fluidity without separating the aggregate. When the flow value is less than 200 mm, the fluidity of the water stop agent 11 is not sufficient. On the other hand, when it exceeds 300 mm, the aggregate contained in the water-stopping agent 11 may be separated. More preferably, it is 230-295 mm, Most preferably, it is 260-290 mm. The mortar mixer 21 was operated at 30 rpm using TMM-12 (manufactured by Dragonfly Industries Co., Ltd.).

  As shown in FIG. 2, the water-stopping agent 11 of the embodiment is temporarily stored in the hopper 23, then sucked by the mortar pump 25, and pumped to the boring machine 29 as shown in FIG. 1. A squeeze pump MM153 (manufactured by Shin Meiwa Kogyo Co., Ltd.) was used for the mortar pump 25, and a D-type boring machine DM-03 (manufactured by Toho Underground Koki Co., Ltd.) was used for the boring machine 29.

  In the embodiment, as shown in FIG. 1, the water-stopping agent 11 is applied against water leakage from a crack generated on a discontinuous surface (cold joint surface 35) of the concrete connection surface 33 of the dam body 31. Used to stop the water. The non-destructive inspection method such as the ultrasonic method or the impact elastic wave method is used to check the water leakage path of the dam body, excavate to the crack of the cold joint surface 35 with the boring machine 29, and the water-stopping agent 11 flows into the crack. did.

  Hereinafter, the present invention will be described in more detail with reference to examples. Test examples 2-6, 9-12, 14, 15 and 17-22 are examples, and test examples 1, 7, 8, 13 and 16 are comparative examples.

  The powder part 13 and the liquid part 15 having the composition shown in Tables 1 to 3 were mixed, and the water stopping agent 11 obtained was measured for flow value, compressive strength (28 days), and workability.

  The flow value is a test for evaluating the fluidity of the water-stopping agent 11 and was measured according to “Physical Test Method for Cement (JIS R 5201: 2015) 12 Flow Test”. The greater the value of the flow value, the higher the fluidity of the water stop agent 11.

  The compressive strength is a test for evaluating the strength of the water-stopping agent 11, and is based on “Concrete base preparation coating material (JIS A 6916: 2014) 7.12 compressive strength”. Was measured. The greater the value of the compressive strength, the higher the strength of the water stop agent 11.

As workability, bleeding, pot life, density change rate and stability were measured. The bleeding is measured according to a concrete bleeding testing method (JIS A 1123: 2012), and after 2 hours of mixing, the bleeding is less than 0.5%. Were evaluated as Δ, and those exceeding 2.0% were evaluated as ×. The pot life is measured according to the concrete setting time test method (JIS A 1147: 2007). The time until the penetration resistance value reaches 3.5 N / mm ² is measured as the initial time of the concrete, and the initial time is 2 hours. The above were evaluated as ◯, the case of 1 hour or more and less than 2 hours as Δ, and the case of less than 1 hour as x. The density change rate is measured by measuring the density change rate of the water stop agent 11 before and after passing through the mortar pump 25 in the pumping of the water stop agent 11, and the density change rate is 2% or less. The following were evaluated as Δ and those exceeding 5% as x. The stability is such that the water-stopping agent 11 is circulated using the mortar pump 25, and the mortar pump 25 is stopped in the mortar pump 25 in less than 1 hour if the water-stopping agent 11 is not clogged for 1 hour or more. The case where clogging of the liquid 11 occurred was evaluated as x.

  Abbreviations are used for raw material names in the table, and the abbreviations and raw material names are described below. Ordinary PC: Ordinary Portland cement (JIS R 5210: 2009), EFS5NA: 5mm electric furnace oxidation slag fine aggregate, EFS2.5NA: 2.5mm electric furnace oxidation slag fine aggregate, EFS1.2NA: 1.2mm electric furnace oxidation Slag fine aggregate, EFG15-05NA: 15-5 mm electric furnace oxidation slag coarse aggregate (above, JIS A 5011-4: 2013), river sand: No. 4 silica sand or No. 5 silica sand (river sand having a particle size of 2 mm or less), Mighty 100: Kao Corporation high performance water reducing agent Mighty 100, 65SH-4000: Shin-Etsu Chemical Co., Ltd. powder thickener Metros 65SH-4000, SN thickener A-850: San Nopco liquid thickener SN thickener A -850, proof 1299: Synthetic resin emulsion manufactured by BASF Corporation (solid content 54% .

Moreover, the surface dry density (g / cm < ³ >) of a raw material is described with an abbreviation below. Ordinary PC: 3.15, EFS5NA: 3.78, EFS2.5NA: 3.78, EFS1.2NA: 3.78, EFG15-05NA: 3.72, River sand: 2.65.

(Test Examples 1 to 7)
In Test Examples 1 to 7, as shown in Table 1, S / C (volume ratio of aggregate / cement of water-stopping agent) of water-stopping agent 11 was changed. In Test Example 1 having a small S / C, the density change rate as workability was inferior. On the other hand, in Test Example 7 having a large S / C, the mortar pump stability as workability was inferior and the compressive strength was also inferior. Test example 4 is the best example.

(Test Examples 4, 8 to 13)
In Test Examples 4 and 8 to 13, as shown in Table 2, the slag aggregate volume content in the aggregate of the water stopping agent 11 is changed. In Test Example 8 with a small slag aggregate volume content, the compressive strength was slightly inferior. On the other hand, in Test Example 13 having a large slag aggregate volume content, the density change rate as workability was slightly inferior.

(Test Examples 4, 14 to 16)
In Test Examples 4, 14 to 16, as shown in Table 3, the particle size of the slag aggregate used for the waterstop agent 11 is changed. In Test Example 16 using slag aggregate EFG15-05NA having a large particle size, the stability of the mortar pump as workability was inferior.

(Test Examples 17 to 22)
In Test Examples 17 to 22, as shown in Table 4, the raw materials used for the waterstop agent 11 are changed. In Test Examples 17 and 19 in which no water reducing agent was used, the amount of water was required, so the compressive strength was slightly inferior. In Test Examples 17 and 18 where no thickener was used, bleeding as workability was slightly inferior. In Test Examples 20 to 22 using a synthetic resin, although not shown in the table, the water-stopping agent 11 has flexibility and is considered to have an effect of absorbing vibrations received by the structure.

  DESCRIPTION OF SYMBOLS 11 ... Water stop agent, 13 ... Powder part, 15 ... Liquid part, 21 ... Mortar mixer, 23 ... Hopper, 25 ... Mortar pump, 29 ... Boring machine.

Claims (3)

A water-stop agent containing cement, an aggregate containing slag aggregate, and water,
S / C (volume ratio of aggregate / cement) is 3 to 5.5,
The volume content of the slag aggregate in the aggregate is 50 to 90%,
The slag aggregate has a particle size that passes 90% by mass or more of a sieve having a nominal opening of 4.75 mm as defined in Test sieve-Part 1: Metal mesh sieve (JIS Z 8801-1: 2006). ,
A water-stop agent characterized by that.   The water stopping agent according to claim 1, wherein the slag aggregate is an electric furnace oxidation slag aggregate.   The water stopping agent according to claim 1 or 2, wherein a flow value defined in "Cement physical test method (JIS R 5201: 2015) 12 flow test" is 200 to 300 mm.

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