JP6701574B2 - Injection material, filling method of injection material - Google Patents

Description

  The present invention relates to an injectable material that can be injected into a void, and more particularly to an injectable material having plasticity and a method for filling the injectable material.

  BACKGROUND ART Conventionally, an injection material configured to be injected into a void (a crack, a cavity, or the like) formed in a structure and hardened is known. Such infusate is constructed to have some plasticity in order to prevent it from escaping from the void immediately after injection.

  As such an injection material, there is known an injection material formed by mixing an A liquid containing cement, which is a hydraulic material, and water, and a B liquid containing bentonite, which imparts plasticity, and water ( See Patent Document 1). Since the liquid A and the liquid B have better fluidity than the injection material, it is possible to perform long-distance pressure feeding using a pump or the like. Therefore, even when it is difficult to pump the injection material itself over a long distance, the solutions A and B are separately pumped over a long distance, and the solutions A and B are mixed immediately before the void to form the injection material. By doing so, it is possible to inject the injection material into the void from a position relatively far from the void.

  By the way, the above-mentioned two-liquid type injection material requires a facility for pumping the liquid A and a facility for pumping the liquid B, so that a relatively large-scale facility is required. Therefore, a one-pack type injection material that can be used with simpler equipment has been proposed (see Patent Document 2). As a method of injecting such a one-pack type injection material into the void, in advance, all components such as cement, bentonite, and water are kneaded to form an injection material, and the injection material is pumped and injected into the void. It is a thing.

JP-A-11-310779 JP, 2002-155277, A

  However, the above-mentioned one-liquid type injecting material is configured so that the flow value immediately after production is relatively high so as to enable pressure feeding. That is, the above-mentioned one-liquid type injecting material is injected into the void in a state where it is not sufficiently plasticized, and therefore may flow out from the void depending on the shape and position of the void.

  Therefore, it is an object of the present invention to provide an injectable material that exhibits sufficient plasticity during injection into a void and can suppress the outflow from the void, and a method for filling the injectable material.

  The injection material according to the present invention is formed by kneading cement, blast furnace slag, bentonite, and water. Bentonite has a swelling power of 30 ml/2 g or more, and cement and blast furnace slag with respect to the mass of bentonite. The ratio of the total mass of the cement is 0.7 or more and 1.9 or less, the ratio of the mass of the cement to the total mass of the cement and the blast furnace slag is 0.01 or more and 0.1 or less, and the mass of the bentonite. The mass ratio of water is 8.3 or more and 9.0 or less.

  The injectable material according to the present invention is an injectable material that is pumped toward the voids and filled into the voids, which is formed by kneading cement, blast furnace slag, bentonite, and water. The swelling power is 30 ml/2 g or more, the ratio of the total mass of cement and blast furnace slag to the mass of bentonite is 0.7 or more and 1.9 or less, and the mass of cement with respect to the total mass of cement and blast furnace slag. Is 0.01 or more and 0.1 or less, and the ratio of the mass of water to the mass of bentonite is 8.3 or more and 9.0 or less.

  According to such a configuration, the swelling power of bentonite is 30 ml/2 g or more, and the ratio of the total mass of cement and blast furnace slag to the mass of bentonite is 0.7 or more and 1.9 or less. The ratio of the mass of cement to the total mass of slag is 0.01 or more and 0.1 or less, and the ratio of the mass of water to the mass of bentonite is 8.3 or more and 9.0 or less. Higher plasticity can be exhibited than in the case where the plasticity is exhibited by the action of bentonite alone in a relatively large amount. As a result, sufficient plasticity is exhibited during injection into the voids, and it is possible to suppress the outflow of the injection material from the voids.

  The ratio of the mass of cement to the total mass of cement and blast furnace slag is preferably 0.01 or more and 0.07 or less.

  According to such a configuration, the ratio of the mass of the cement to the total mass of the cement and the blast furnace slag is 0.01 or more and 0.07 or less, so that high plasticity is exhibited during injection into the voids, It is possible to more effectively suppress the outflow of the injection material from the.

  In the method for filling an injectable material according to the present invention, any one of the above injectable materials is pressure-fed toward the void, and the injectable material is filled in the void.

  As described above, according to the present invention, sufficient plasticity can be exhibited at the time of injection into the void, and outflow from the void can be suppressed.

  An embodiment of the present invention will be described below.

  The injection material according to the present invention is configured to be injected into the voids (cracks, cavities, etc.) formed in the structure to be cured. Specifically, the injection material is formed by kneading cement, blast furnace slag, bentonite, and water.

  The cement is not particularly limited, for example, ordinary Portland cement, early strength Portland cement, super early strength Portland cement, moderate heat Portland cement, sulfate resistant Portland cement, Portland cement such as white Portland cement, and the like, Examples include ultra-quick cement and alumina cement. Further, various kneading cements obtained by kneading Portland cement with fly ash and the like can also be used. As the cement, it is particularly preferable to use ordinary Portland cement.

  The blast furnace slag is not particularly limited, and for example, those specified in JIS A 6206 "Blast furnace slag fine powder for concrete" can be used. By including the blast furnace slag in the injection material, the strength development after the injection material is cured becomes good.

  The bentonite has a swelling power of 30 ml/2 g or more, and may be 35 ml/2 g or more. When the swelling power of bentonite is the above value, sufficient plasticity can be imparted to the injectable material, and at the same time, plasticity can be exhibited immediately after kneading even in a relatively short time of kneading. The swelling power is determined by the Japan Bentonite Industry Association "Bentonite (powder) swelling test method (JBAS-104)".

  The water is not particularly limited, and for example, general tap water (clean water) can be used. The mass ratio of water to the mass of bentonite is 8.3 or more and 9.0 or less, and preferably 8.5 or more and 8.8 or less.

  The injection material may include other components. For example, one or more selected from admixtures, fine aggregates, coarse aggregates, water reducing agents, retarders, dispersants, etc. may be included in the injectable material. Examples of the admixture include fly ash, silica fume, gypsum, limestone fine powder, quick lime fine powder and the like.

  The content of each component constituting the injection material is not particularly limited. Specifically, the ratio of the total mass of cement and blast furnace slag to the mass of bentonite is 0.7 or more and 1.9 or less, and preferably 1.0 or more and 1.9 or less. The ratio of the mass of cement to the total mass of cement and blast furnace slag is 0.01 or more and 0.1 or less, and preferably 0.03 or more and 0.07 or less. The mass ratio of cement to the total mass of cement, blast furnace slag and bentonite (hereinafter, also referred to as mass of powder component) is preferably 0.4 mass% or more and 5.0 mass% or less. The ratio of the mass of cement to the mass of bentonite is preferably 0.01 or more and 0.1 or less.

  The flow value of the injection material configured as described above is not particularly limited as long as the flow value is such that the injection material does not flow out of the space after the injection material is injected into the space. For example, the flow value of the injection material is preferably 125 mm or less, and more preferably 120 mm or less, from the viewpoint of the limited area injection by plasticity. Further, in consideration of the pumpability, the flow value of the injection material is preferably a flow value that can be pumped using a general equipment for pumping concrete or mortar, for example, preferably 80 mm or more. More preferably, it is 100 mm or more. The flow value of the injection material is measured by the method described in the examples below.

Further, the compressive strength when the injection material configured as described above is cured is not particularly limited, and may be strength enough to be self-supporting (in other words, the shape can be maintained). , 0.6 N/mm ² or more, more preferably 1.0 N/mm ² or more. The compressive strength is measured by the method described in Examples below.

  The method for producing the injection material configured as described above is not particularly limited. For example, first, cement, blast furnace slag, and bentonite are mixed to prepare a powder mixture. When other powder components are mixed with the injection material, the powder mixture may be prepared by mixing the other powder components together with cement, blast furnace slag, and bentonite. The mixing method for producing the powder mixture is not particularly limited, and for example, a powder mixing device such as a V-type mixer, a Nauta mixer, a pan-type mixer, a ribbon-type mixer or the like can be used. Next, water is added to the powder mixture and kneaded to prepare an injection material. The method of kneading the powder mixture and water is not particularly limited, and for example, a kneading device such as a hand mixer or a mortar mixer can be used.

  The injection material produced as described above is pumped toward the void. Specifically, since the above-mentioned injection material exhibits plasticity such that the flow value becomes the above-mentioned value relatively early after manufacturing, the pumping distance is relatively short (for example, about 30 m). Suitable for large-scale construction sites.

  As described above, in the injection material according to the present invention and the method for filling the injection material, sufficient plasticity is exhibited during injection into the void, and the outflow from the void can be suppressed.

  That is, the swelling power of bentonite is 30 ml/2 g or more, the ratio of the total mass of cement and blast furnace slag to the mass of bentonite is 0.7 or more and 1.9 or less, and the total mass of cement and blast furnace slag is The ratio of the mass of cement to 0.01 is 0.01 or more and 0.1 or less, and the ratio of the mass of water to the mass of bentonite is 8.3 or more and 9.0 or less. Higher plasticity can be exhibited than when plasticity is exhibited by the action of bentonite alone. As a result, sufficient plasticity is exhibited during injection into the voids, and it is possible to suppress the outflow of the injection material from the voids.

  Further, the ratio of the mass of the cement to the total mass of the cement and the blast furnace slag is 0.01 or more and 0.07 or less, so that high plasticity is exhibited at the time of injection into the void, so that the injection material Outflow can be suppressed more effectively.

  The injection material according to the present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the present invention. Further, the configurations and methods of the plurality of embodiments described above may be arbitrarily adopted and combined (the configurations and methods according to one embodiment may be applied to the configurations and methods according to other embodiments. Of course, the configurations and methods according to the various modifications described below may be arbitrarily selected and used in the configurations and methods according to the above-described embodiments.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

<Materials used>
・Cement (symbol NC): Ordinary Portland cement (Sumitomo Osaka Cement Co., Ltd.)
・Blast furnace slag (symbol S): Essment (manufactured by Nippon Steel & Sumikin Blast Furnace Cement Co., Ltd.)
・Bentonite 1 (symbol B1): Product name Super Clay (Swelling power 30ml/2g, Hojun Co.)
Bentonite 2 (symbol B2): Brand name Western gel (swelling power 36 ml/2 g, manufactured by Mitsubishi Corporation)
Bentonite 3 (symbol B3): Product name Asama (swelling power 7 ml/2 g, Hojun Co.)
・Water (symbol W): Tap water

<Formulation of Examples and Comparative Examples>
Using the above-mentioned materials used, injection materials of Examples and Comparative Examples were prepared with the formulations shown in Tables 1 to 4.
“W/P” in Table 4 is the ratio of the mass of water to the mass of the powder component.
Further, “(S+NC)/B” in Table 4 is the ratio of the total mass of cement and blast furnace slag to the mass of bentonite.
Further, “NC/(S+NC)” in Table 4 is the ratio of the mass of cement to the total mass of blast furnace slag and cement.
Further, “W/B” in Table 4 is the ratio of the mass of water to the mass of bentonite.

<Preparation of injection material>
The method for producing the injection material of each example and each comparative example is as follows. Specifically, cement, blast furnace slag, and bentonite were mixed using a mixing device to prepare a powder mixture.
The obtained powder mixture and water were kneaded to prepare an injection material of each example and each comparative example. As a kneading condition, a 1100 rpm hand mixer was used, and after pouring the powder into a container in which a predetermined amount of water was weighed, kneading was performed for 2 minutes and 30 seconds, scraped off, and kneading for 30 seconds, and kneading was performed.

<Measurement of flow value>
The flow value of the injection material in each example and each comparative example was measured based on JHS-A-313-1992 "Test method of air mortar and air milk: Consistency test of injection material by cylinder method". The measurement results of the flow value are shown in Table 4 below.

<Measurement of compressive strength>
The compressive strength of the injection material in each example and each comparative example was measured based on JIS A 1216 "uniaxial compression test of soil". The measurement results of the compressive strength are shown in Table 4 below. In addition, those that did not stand by themselves (cannot maintain the shape) during the measurement were not cured.

<Summary>
From the table, it can be seen that each example has a lower flow value and higher compressive strength than each comparative example. Further, in each example, it is recognized that the flow value is such that pumping is possible. That is, in an injectable material having a relatively large amount of water in which the ratio of the mass of water to the mass of bentonite is 8.3 or more and 9.0 or less, the bentonite having a swelling power of 30 ml/2 g or more is used, and The total mass ratio of cement and blast furnace slag is 0.7 or more and 1.9 or less, and the mass ratio of cement to the total mass of cement and blast furnace slag is 0.01 or more and 0.1 or less. It is recognized that by adjusting the content of cement, an injectable material that exhibits sufficient plasticity to the extent that it can be pumped and that exhibits sufficient compressive strength when injected into the voids and cured.

Claims (4)

Cement, blast furnace slag, bentonite, and water are kneaded and formed,
The swelling power of bentonite is 30 ml/2 g or more and 36 ml/2 g or less ,
The ratio of the total mass of cement and blast furnace slag to the mass of bentonite is 0.7 or more and 1.9 or less,
The ratio of the mass of cement to the total mass of cement and blast furnace slag is 0.01 or more and 0.1 or less,
The ratio of the mass of water to the mass of bentonite is 8. An injection material that is 5 or more and 9.0 or less. An injectable material which is pumped toward the voids and filled in the voids,
Cement, blast furnace slag, bentonite, and water are kneaded and formed,
The swelling power of bentonite is 30 ml/2 g or more and 36 ml/2 g or less ,
The ratio of the total mass of cement and blast furnace slag to the mass of bentonite is 0.7 or more and 1.9 or less,
The ratio of the mass of cement to the total mass of cement and blast furnace slag is 0.01 or more and 0.1 or less,
The ratio of the mass of water to the mass of bentonite is 8. An injection material that is 5 or more and 9.0 or less.   The injection material according to claim 1 or 2, wherein the ratio of the mass of the cement to the total mass of the cement and the blast furnace slag is 0.01 or more and 0.07 or less.   A filling method of the injectable material according to claim 1, wherein the injectable material according to any one of claims 1 to 3 is pressure-fed toward the void and the injectable material is filled into the void.