JPH10152684A - Grout and method of grouting by using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a high strength and long-term stability by injecting a grout consisting of a liquid A containing a cement, a material containing calcium hydroxide, and an organic acid compound such as a hydroxycarboxylic acid as the effective constituents and a liquid B containing an alkali metal aluminate as the effective constituent. SOLUTION: The liquid A is prepared by kneading in a mixer 100 pts.wt. cement such as Portland cement with a material containing calcium hydroxide, such as carbide refuse, and having a particle size of 100μm or smaller, in an amount of 1-50 pts.wt. in terms of calcium hydroxide, and 0.1-50 pts.wt. organic acid compound comprising a hydroxycarboxylic acid, such as citric acid, or its salt. The liquid B is prepared which contains 1-10 pts.wt. alkali metal aluminate such as sodium aluminate. Water in an amount sufficient to provide a water-cement ratio of (100 to 300):100 is distributed to the liquid A and the liquid B so that these two liquids may be approximately equal in volume. A grout made by mixing 100 pts.wt. liquid A and 2-20 pts.wt. liquid B is injected into a prescribed place.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection material used for prevention of ground collapse and ground improvement, and an injection construction method using the same.

[0002]

2. Description of the Related Art Conventionally, in order to improve soft ground and to prevent collapse of a ground or a tunnel, for example, materials are kneaded with a two-stage mixer, and are pumped by a grout pump. Into the ground or ground to reinforce them.

[0003] As a pouring method for preventing the collapse of the ground and improving the ground, there are a water glass-cement pouring method using a water glass solution and a cement slurry, and a solution type method using a water glass solution and an organic acid solution. A water glass-based injection method and a cement-based injection method using a cement slurry and a rapidly hardened material-containing liquid have been proposed (Japanese Unexamined Patent Publication No. Hei 6-263498, "Actual practice of chemical liquid injection method", Kashima Publishing Co. Published in 1988, from the investigation and design to construction of the chemical liquid injection method, Japan Society of Soil Engineering, published in 1988, "Cement Chemical Liquid Injection Method", Gihodo, published in 1968, and "Manual for Improvement of Ground Using Cement-Based Solidification Material" Japan Cement Association 1994, etc.).

In each of these methods, a slurry or a liquid is pumped by a separate system using a hose or the like, mixed at the tip, injected, and cured within a few minutes. However, in the water glass cement-based injection method and the cement-based injection method, since one or both of the liquids are cement-based, the hydration reaction of the cement hardens in a short time of about 4 to 6 hours and the injection of the injection material. There was a problem that time was limited. In addition, there is a problem that a surplus amount is discarded and a loss of the injected material is caused in order to mix the injected material more than necessary for the injection of the ground or the ground. Furthermore, the solution type water glass injection method has a problem that durability cannot be obtained.

As a result of various studies to solve these problems, the inventor of the present invention has obtained the knowledge that can solve the above problems by injecting using a specific injection material, and has completed the present invention.

[0006]

That is, the present invention relates to an injection material containing cement, a calcium hydroxide-containing substance, an organic acid, and an alkali metal aluminate as active ingredients. It is an injection material comprising a liquid A containing an organic acid as an active ingredient and a liquid B containing an alkali metal aluminate as an active ingredient. Further, there is provided an injection construction method characterized by injecting these injection materials.

Hereinafter, the present invention will be described in detail.

[0008] The cement used in the present invention includes various commonly used portland cements such as ordinary, early and ultra early, etc., various mixed cements obtained by mixing blast furnace slag, fly ash or silica with these portland cements, calcium aluminum, etc. Various special cements containing admixtures such as silicate or gypsum or a setting retarder, modified Portland cement containing 3CaO.SiO ₂ or 11CaO.7Al ₂ O ₃ .CaF ₂ as an active ingredient can be used.

Examples of the calcium hydroxide-containing substance (hereinafter, referred to as slaked lime) used in the present invention include slaked lime and carbide slag by-produced when acetylene is generated from calcium carbide. The use of carbide slag is preferred in terms of the best strength development and the ability to recycle waste. Although the particle size of slaked lime is not particularly limited,
It is preferably 100 μm or less, more preferably 60 μm or less.
If it exceeds 100 μm, coagulation may not occur when mixed with an alkali metal aluminate. The amount of slaked lime used
In terms of calcium hydroxide, the amount is preferably 1 to 50 parts by weight, more preferably 3 to 10 parts by weight, based on 100 parts by weight of cement. If the amount is less than 1 part by weight, it hardly hardens to set and harden when mixed with an alkali metal aluminate.
The gel time of the solution may be significantly shortened, or the 28-day strength may be reduced.

The organic acids used in the present invention have an effect of retarding the setting of cement, and the use of hydroxycarboxylic acids or salts thereof is preferred. Examples of the hydroxycarboxylic acid or a salt thereof include one or more of various hydroxycarboxylic acids such as citric acid, gluconic acid, tartaric acid, lactic acid, and malic acid, or a sodium salt or a potassium salt thereof, and the amount thereof is directly proportional to the amount used. It is more preferable to use citric acid from the viewpoint that the setting time becomes longer. The amount of the organic acids to be used is preferably 0.1 to 50 parts by weight, more preferably 0.5 to 20 parts by weight, most preferably 1 to 9 parts by weight based on 100 parts by weight of cement. If the amount is less than 0.1 part by weight, the retarding effect is small, and if it exceeds 50 parts by weight, there is a possibility that hardening hardens when mixed with an alkali metal aluminate.

The alkali metal aluminate (hereinafter referred to as aluminate) used in the present invention has an effect of rapidly setting and hardening an injection material, and examples thereof include sodium aluminate and potassium aluminate. A liquid having a shape or a liquid dissolved in water can be used. When used as a liquid, it is preferable to use potassium aluminate because of its high solubility. In the present invention, the aluminate aqueous solution is concentrated and can be used, for example, as a slurry having a solid content of 50% by weight. The amount of the aluminate used is preferably 1 to 10 parts by weight, more preferably 3 to 7 parts by weight, based on 100 parts by weight of the cement. If the amount is less than 1 part by weight, the setting may be delayed. If the amount exceeds 10 parts by weight, the setting time may be delayed.

The amount of water used in the present invention is preferably 100 to 300% in terms of a water / cement ratio (W / C), and 100 to 200%.
% Is more preferred. If it is less than 100%, the liquid A or liquid B alone may cause coagulation in a short time. If it exceeds 300%, the coagulation time may be delayed and the strength may be reduced. In addition, the amount of water used in the present invention is the total amount of the solution A and the solution B, and the amount of water to be distributed to the solution A and the solution B is an amount that the solution A and the solution B have the same volume. Is preferred.

[0013] The method for adding water used in the present invention is not particularly limited.
A method of adding with a hose or the like is possible.

As a device for injecting the injection material of the present invention, there are a mixer for kneading, a two-stage mixer, a grout pump, a flow meter, a water storage tank, and a water pump.

The mixing method is not particularly limited. For example, first, a liquid A containing cement as an active ingredient is kneaded in an upper mixer of a two-stage mixer. Drop into mixer. Kneading water used at the time of kneading, for example, by pumping water in a water storage tank,
Feed to a two-stage mixer. A method is possible in which the solution B containing an aluminate as an active ingredient is transferred from a drum to a tank, the solution A and the solution B are sent by a grout pump, and mixed at the tip.

When the injection material of the present invention is injected, slaked lime can be mixed with either liquid A or liquid B. For example, cement, slaked lime, and organic acids are used as active ingredients. A solution and B containing aluminate as an active ingredient
It is preferable to divide the liquid into two liquids. In the case of using two liquids, an organic acid or water and further slaked lime are added to obtain a liquid A of the cement slurry so that the cement in the liquid A does not set and harden for a long time. By adding a liquid B containing an aluminate as an active ingredient to the liquid A at a desired time, the injected material is quickly set and hardened. In this case, at the time of pouring, it is also possible to pump the solution A and the solution B to the pouring part by a separate system using a hose or the like, mix them at the tip, and then pouring them into the ground or the ground.

The mixing ratio of the liquid A and the liquid B used in the present invention is preferably 2 to 20 parts by weight, more preferably 6 to 14 parts by weight, based on 100 parts by weight of the liquid A. If the amount is less than 2 parts by weight, the setting may be delayed, and if it exceeds 20 parts by weight, the setting may be delayed.

[0018]

The present invention will be further described below with reference to examples.

EXAMPLE 1 100 parts by weight of cement, 100 parts by weight of water, 100 parts by weight of water, 0.5 parts by weight of slaked lime and organic acids a in the amount shown in Table 1 in terms of calcium hydroxide were put into a mixer and kneaded. To prepare a solution A, and the setting time was measured. The results are also shown in Table 1.
Next, 10 parts by weight of Solution B containing 100 parts by weight of aluminate α in 100 parts by weight of Solution B was added to 100 parts by weight of Solution A.
The solution A was kneaded and added every kneading time, and the setting time was measured. The results are also shown in Table 1.

<Materials Used> Cement: ordinary Portland cement, commercially available slaked lime A: carbide slag, Blaine value 3,000 cm ² / g, calcium hydroxide content 95.8% by weight slaked lime B: slaked lime, commercially available organic acids a: Citric acid, commercial product Aluminate α: potassium aluminate, commercial product Water: tap water

<Measurement method> Setting time: The time until liquid A is put into a nylon bag and hardened by touching with a finger.

[0022]

[Table 1]

As is clear from Table 1, the use of slaked lime A shortens the setting time when the liquid A and the liquid B are mixed. In addition, the setting time tended to be shorter as the mixing time with the solution B was later.

Example 2 The procedure of Example 1 was repeated, except that 100 parts by weight of cement, 5 parts by weight of slaked lime A, and the organic acids shown in Table 2 were used. The results are also shown in Table 2.

<Materials used> Organic acids b: gluconic acid, commercially available Organic acids c: tartaric acid, commercially available

[0026]

[Table 2]

As is apparent from Table 2, the setting and hardening time can be arbitrarily adjusted depending on the amount of the organic acid used.

Example 3 Except that 100 parts by weight of cement, 5 parts by weight of slaked lime, and 0.5 parts by weight of organic acids a were used, and aluminate shown in Table 3 was used for 100 parts by weight of cement. Was performed in the same manner as in Example 1. The results are also shown in Table 3.

<Materials> Aluminate β: sodium aluminate, commercially available

[0030]

[Table 3]

As is apparent from Table 3, when the amount of the aluminate used is 3 to 7 parts by weight, the setting property is the strongest.

Example 4 The same procedure as in Example 1 was carried out except that 100 parts by weight of cement, 5 parts by weight of slaked lime A, and 0.5 parts by weight of organic acids a were used and water shown in Table 4 was used. The results are also shown in Table 4.

[0033]

[Table 4]

As is apparent from Table 4, as the amount of water used increases, the setting time tends to become slow.

Example 5 100 parts by weight of cement, 5 parts by weight of slaked lime A, and 0.5 parts by weight of organic acids a were used, and the amount of the solution B to 100 parts by weight of the solution A was blended as shown in Table 5. Except for this, the procedure was the same as in Example 1. The results are also shown in Table 5.

[0036]

[Table 5]

As is clear from Table 5, the setting time is shortest when the amount of the solution B is 10 parts by weight with respect to 100 parts by weight of the solution A.

Example 6 The procedure of Example 1 was repeated, except that the solution B was added immediately after the kneading of the solution A with the composition shown in Table 6, and the compressive strength was measured for each predetermined material age. The results are also shown in Table 6.

<Measurement method> Compressive strength: based on JIS R 5201

[0040]

[Table 6]

As is clear from Table 6, when potassium aluminate is added immediately after kneading, sufficient strength can be obtained for preventing the collapse of the ground and improving the ground.

[0042]

The injection material of the present invention cures in a short time, so that the injection time can be adjusted and the material loss of the injection material is reduced. Further, by using the injection material of the present invention, effects such as high injection strength and long-term stability can be obtained. Furthermore, solution A and B
By separating into two liquids, unlike the conventional cement-based injection material, there is no need to worry about hardening of the cement slurry in the mixer, and the material loss of the injection material can be reduced.
When mixed with the liquid, it can be cured in a short time, and when the liquid A is kneaded for a long time, the addition of the liquid B shortens the setting time.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI // C09K 103: 00

Claims (3)

[Claims] Cement, calcium hydroxide containing material,
An injection material containing an organic acid and an alkali metal aluminate as active ingredients. 2. A cement, a calcium hydroxide-containing substance,
And an injection material comprising a liquid A containing an organic acid as an active ingredient and a liquid B containing an alkali metal aluminate as an active ingredient. 3. An injecting method, comprising injecting the injecting material according to claim 1 or 2.