JP2007045658A - Delayed-plastic grout material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a delayed-plastic injection (grout) material in which a liquid material to be used does not harden and its fluidity does not fall off in a brief span of time even in no addition of retarders, and also favorable plasticity, strength or the like is expressed even in various application stages or environments. <P>SOLUTION: This plastic grout material is produced by mixing the liquids A and B in a volume ratio of 1:1-1:5, wherein the liquid A contains a mixture of slag and/or fly ash and gypsum in the mass ratio of 95:5-30:70 and water in the mass ratio of 1:40-1:200, and the liquid B contains a plasticizer and water in the mass ratio of 1:3-1:20. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a grout material used for ground, civil engineering structure cavity filling, lightweight embankment, landfill, and the like, and more particularly, to a delayed plastic grout material using a latent hydraulic material.

For grout materials that use cavities and gaps in the ground and civil engineering structures for filling, etc., in order to inject efficiently and surely into the target cavity filling part, and to prevent leakage into surrounding gaps, etc. In order to prevent the material from being diluted with ground water or running water, it is often desirable that the injected material has properties as a gel-like aggregate. And such an injection material needs to maintain fluidity | liquidity sufficient for pumping with a pump, and needs to harden | cure reliably in a filling part, in order to exhibit the performance as a grout material.
A plastic injection material (plastic grout material) having such properties and functions has been proposed and put into practical use.
For example, a plastic filling material for cavity filling, lightweight embankment and landfill obtained by mixing and stirring cement milk and bentonite milk has been proposed (see Patent Document 1). It has been proposed to obtain a non-flowable plastic grout material by adding a mixed fluid swelling liquid (see Patent Document 2).

However, in these plastic injection materials, since cement milk or fluid mortar is used as a curing aid, the fluidity of cement milk or the like itself is lowered or cured after a predetermined time. .
For this reason, conventionally, in order to delay the curing of the plastic grout material, a retarder used in concrete or the like is used, and in order to obtain a predetermined delay effect, the amount of the retarder has been adjusted. In this case, the predetermined delay effect can be exhibited in the laboratory test, but the effect of the retarder cannot be exhibited as planned depending on the situation at the site (temperature, underwater / air curing conditions, presence / absence of load pressure). In the case of plastic grout materials using clay agglomeration, clay adsorbs the retarder, so adjustment of the curing time with the retarder is extremely complicated because it must be added in a larger amount than the usual addition amount. It is. In addition, there may be cases where the effect of the retarding agent cannot be expected, such as when the injection is interrupted for several hours to several days due to the completion of daily construction or troubles in the manufacturing plant. There is. In addition, it is necessary to process the washed waste water, which is troublesome.

In Patent Document 3, cement hydrate is used as a delay type plastic injection material in which a liquid material to be used does not harden in a short time or does not cause a decrease in fluidity without adding a retarder or the like. It is formed by stirring and mixing an alkaline liquid material (stimulating liquid) mixed with a curing aid such as a liquid material (hardening liquid) containing a latent hydraulic substance such as blast furnace slag and a plasticizing material such as bentonite. Plastic injection materials have been proposed.
In this plastic injection material, a hardening liquid obtained by mixing a latent hydraulic substance such as blast furnace slag and a plasticizing material such as bentonite comes into contact with the stimulating liquid and develops strength. And in various application scenes and application environments of the grout method, there is a case where the plasticity expression, the strength expression, etc. are not always sufficient, although the delay is caused, for example, when the mixed state of both liquids is not good.

Japanese Patent No. 3378501 Japanese Patent Laid-Open No. 11-124574 Japanese Patent No. 3366617

  In view of such a situation, the present invention is a delay type plastic injection material (plastic grout material) in which the liquid material to be used does not harden in a short time and does not cause a decrease in fluidity. An object of the present invention is to provide a delayed plastic grout material that exhibits good plasticity and strength even in the scene and application environment.

As a result of intensive studies, the present inventors have found that the liquid A is a slow-hardening agent by adding gypsum and water in a specific mass ratio to blast furnace slag, which is a latent hydraulic substance, and plasticization. The present invention was completed by finding that a plastic grout material obtained by mixing a B liquid (plasticized material liquid) containing a material and water at a specific mass ratio at a predetermined volume ratio can solve the above problems.
In addition, since slag and gypsum often use industrial by-products and the quality is not stable, an appropriate amount of retarder may be used in order to ensure sufficient retardance.

That is, the present invention provides a liquid A containing a mixture of slag and / or fly ash and gypsum in a mass ratio of 95: 5 to 30:70 and water in a mass ratio of 1:40 to 1: 200, and a plasticizer. A plastic grout material in which liquid B containing water and water in a mass ratio of 1: 3 to 1:20 is mixed at a volume ratio of 1: 1 to 1: 5 is provided.
The plasticizer is preferably at least one selected from bentonite, attapulgite, and metakaolin, and anhydrous gypsum is most preferably used as the gypsum.
Moreover, the plastic grout material which makes 0.01-0.5% of mass ratio contain the retarder in the said A liquid with respect to the mixture of a latent hydraulic material and gypsum is provided.

The delayed plastic grout material of the present invention can delay the development of strength while maintaining the plastic state. For this reason, limited injection is possible without any deviation from cracks.
The A liquid of the present invention has a slow-hardening property and is usually unsolidified for about 3 to 7 days, and the grout material obtained by mixing the A liquid and the B liquid is in a state of maintaining a plastic state and not being cured. Thereafter, the strength of the grout material develops with the hardening of the component A, and it becomes a solidified state in about 3 to 7 days.
That is, the liquid material (A liquid, B liquid) and the liquid mixture to be used do not harden in a short period of time or the fluidity does not deteriorate. This eliminates the need for cleaning and saves work and eliminates the problem of waste water treatment for cleaning water.
Furthermore, according to the present invention, there is provided a delayed plastic grout material having good plasticity expression, strength expression and the like in various application scenes and application environments.

Embodiments of the present invention will be described below.
The liquid A (slow-curing curable liquid) of the present invention is obtained by adding gypsum and water in a specific mass ratio to blast furnace slag, which is a latent hydraulic substance.

  The latent hydraulic substance contains a mineral component that can be hardened by forming a hydrate by a hydration reaction, but it does not initiate a hydration reaction even when contacted with water under normal conditions. In the present invention, a slag powder such as blast furnace slag and / or fly ash (coal ash) is used.

Plaster causes hardening of slag and / or fly ash, and when it is small, the setting of the plastic grout material is delayed, so the addition of a retarder can be reduced, and when it is large, the strength expression of the plastic grout material is high. Become. In addition, it has the function of causing aggregation and plasticization of plasticized materials such as bentonite. In the present invention, the gypsum can be any of anhydrous gypsum, hemihydrate gypsum, and dihydrate gypsum. Of these, anhydrous gypsum is most preferably used in terms of strength development of the grout material.
The liquid A is a mixture of slag and / or fly ash and gypsum in a mass ratio of 95: 5 to 30:70, preferably 90:10 to 70:30, and water, and a mass ratio of 1:40 to 1: 200, preferably Contains from 1:50 to 1: 150.

The B liquid (plasticizing material liquid) of the present invention mixes a plasticizing material for plasticizing the grout material and water for dispersing the plasticizing material.
The plasticizing material such as bentonite in the liquid B swells in water and is charged with negative ions. When liquid A is mixed with this, calcium ions in the gypsum contained in liquid A neutralize the negative charges on the surface of bentonite particles, which causes a rapid agglomeration reaction due to the intermolecular attractive force of the bentonite particles. , Instant plasticity.
As the plasticizer, clay minerals are preferably used, and among them, at least one selected from bentonite, attapulgite, and metakaolin is preferable.
Liquid B contains a plasticizer and water in a mass ratio of 1: 3 to 1:20, preferably 1: 5 to 1:10.
Moreover, in order to improve fluidity | liquidity, the water reducing agent as an admixture can be added to B liquid. As such a water reducing agent, water reducing agents used in concrete such as naphthalene, melamine, and polycarboxylic acid can be used. The amount of the water reducing agent added varies depending on the type of water reducing agent and the product, but is 0.5 to 2.0% by mass with respect to the plasticized material.

In the plastic grout material of the present invention, the liquid A (slow curing curable liquid) and the liquid B (plasticized liquid) are mixed at a volume ratio of 1: 1 to 1: 5, preferably 1: 2 to 1: 4. Is obtained.
The plastic grout material of the present invention having such a composition of liquid A and liquid B and a mixing ratio exhibits a plastic state with a cylinder flow value in the range of 80 to 150 mm.

In addition, since slag and gypsum often use industrial by-products and the quality is not stable, it is effective to add an appropriate amount of a retarder to the liquid A in order to ensure sufficient delay.
As the retarder, a retarder used in concrete or the like can be used, and examples thereof include lignin sulfonate, oxycarboxylate, and saccharide derivatives. Moreover, what is necessary is just to add the retarder of 0.01-0.5 mass part with respect to 100 mass parts of A liquid about the usage-amount of a retarder.

The invention according to the present invention will be further illustrated by the following examples. In addition, the test in an Example was performed as follows.
The flow test was based on the cylinder method, which is the Japan Highway Public Corporation standard test method. The flow value is preferably 80 to 150 mm, more preferably 80 to 120 mm. Those having a flow value of 150 mm or more are not suitable for limited injection or the like (since an 80 mm diameter cylinder is used, it is not less than 80 mm).
The compressive strength of the cured body was measured by the Geotechnical Society standard “uniaxial compression test (JIS A1216)”. It is sufficient that the compressive strength of the grout material cured body in the grout method is 0.5 N / mm ² or more.

Example 1
Blast furnace slag (as defined in JIS R5211 “Blast furnace cement”) as slag, anhydrous gypsum as gypsum, and water are kneaded with the composition shown in Table 1 to prepare solution A, and bentonite (plasticizer) Liquid B was prepared by kneading water having a swell degree of 16: 200 mesh sieve with a particle size of all sizes) and water according to the composition shown in Table 1. The liquid A and liquid B had no material separation and had good pumpability. The two liquids were mixed and stirred to be plasticized (gelled).
Table 1 shows the cylinder flow values (plasticity) immediately after mixing both liquids, and Table 2 shows the changes over time in the compressive strength of the grout after kneading both liquids.

From Table 1, the mass ratio of slag and gypsum, the mass ratio of the mixture and water, and the volume ratio of liquid A and liquid B are those specified by the present invention. It is about 90-100mm, and it turns out that favorable plasticity is shown.
Table 2 also shows that these plastic grout materials of the present invention are generally uncured for about 3 to 7 days, retain the plastic state, and do not exhibit strength.

Claims (6)

  Liquid A containing a mixture of latent hydraulic material and gypsum in a mass ratio of 95: 1 to 30:70 and water in a mass ratio of 1:40 to 1: 200, a plasticizer and water in a mass ratio of 1: 3 A delay type plastic grout material obtained by mixing the liquid B containing ˜1: 20 at a volume ratio of 1: 1 to 1: 5. The delayed plastic grout material according to claim 1, wherein the latent hydraulic material is blast furnace slag and / or fly ash.   The delayed plastic grout material according to claim 1, wherein the plasticizer is at least one selected from bentonite, attapulgite, and metakaolin.   The delayed plastic grout material according to claim 1, wherein the gypsum is anhydrous gypsum.   The delayed type plastic grout material according to claim 1, wherein a water reducing agent is added to the B liquid in a mass ratio of 0.5 to 2.0% with respect to the plasticizer. The retard type plastic grout material according to claim 1, wherein a retarder is contained in the liquid A in a mass ratio of 0.01 to 0.5% with respect to the mixture of the latent hydraulic material and gypsum.