KR880001382B1 - Method for grouting polymer-cement mortar into the weak soil - Google Patents

Abstract

The method for grouting a polymer cement mortar comprises (1) boring a grouting pore in the ground to put into a casing pipe, (2) forming a void space by removing soil particles, fine sands mingled in the gravel layers, and (3) filling up and concretizing the polymer cement mortar into the void space. The polymer cement mortar as a grouting material is composed of cement, sand, compound liquid and 1 or 2-3 of acrylpolymer, cellulose deriv. and polyethylene oxide.

Description

Injection method of polymer cement mortar

1 is a schematic diagram of the present invention.

2 is a flow chart of the injection of the gravel layer according to the present invention.

3 is a detail view of the "A" part of FIG.

* Explanation of symbols for main parts of the drawings

1: injection hole 2: casing pipe

3: strainer 4: gravel layer or sand gravel

5: cesarean 6: voids

7: cement 8: sand

9: water tank 10: mixer

11: aqueous solution of polymer dissolution tank 12: polymer cement mortar stirrer

12 ': polymer cement mortar 13: injection pump

14: injection tube 15: compressor

The present invention relates to a polymer cement mortar grouting body used for the purpose of filling rock layer pores, installing a groundwater order wall in a gravel layer below an underground aquifer, building underground submersible beams, and solidifying a gravel layer.

Conventionally, cement grouting was also possible in underground soils, large voids in rock layers, or gravel layers below aquifers. Examples of such grouting include 1) cement milk type, 2) cement-water glass type, and 3) cement mortar. There is a brother.

The above three methods are explained as follows.

1) Cement milk type grouting is applied by changing the ratio of cement and kneaded water from 1: 1 to 1:10 depending on the soil, and is mainly applied to cracks of soft strata or rocks. In addition, general portland cement and micro-cement were used for the type of cement, depending on the soil pore. This method was performed from the beginning of grouting.

2) Cement-water glass-based grouting is widely used for reinforcement or ordering of soft layers. It is obtained by diluting cement milk suspended in water with A solution and water glass (sodium silicate No. 3) in a suitable ratio. When the solution to B liquid A and B liquid is combined to use the nature of the property.

3) Cement The mortar grouting is injected into strata or gravel layers with very large voids. The ratio of cement, sand and water is various for convenience. However, anything is to be injected into the tube underground, so there must be a large amount of kneading water. And depending on the soil, you can add the complex of 2) .3) and the mineral accordingly.

Common drawbacks in all three of the above are, firstly, injectables in the groundwater-rich strata (especially where the groundwater flows), making them unusable. That is, the deviation of the cement outside the area where the injection is required to cause pollution problems. Secondly, the original ratio of the desired scavenging cannot be maintained and the purpose of grouting scavenging cannot be achieved.

In addition, the individual defect is that the injection is not uniform due to the material separation phenomenon in the injection system of the cement milk system of 1); In the cement-water glass-based injector of 2), water glass, which is the main component of the injection system, is diluted in the groundwater flowing through the large pores, so that the gel concentration does not occur in a timely manner. none. And the strength of the solids is very weak. In addition, in the cement mortar grouting of 3), only sand may remain due to the separation of materials, and thus no mortar is formed, so the effect of the gravel layer injection agent cannot be expected. An example of using an acrylic polymer (acrylic polymer compound) as a soil stabilizer is as follows.

A) Method of stabilizing (solidifying) the surface layer of soil to improve water resistance and erosion resistance. B) Sometimes used as a grouting agent.

이 수불용성의 고결물이 되는 성질을 이용하는 것이다.The surface treatment agent of A) is a _divalent or higher metal salt of a monoter (or polymer) of acrylic acid (CH ₂ = CH-COOH) (e.g. calcium salt of acrylic acid monomer:

This property uses the property of becoming water-insoluble solids.

At this time, the soil is solidified using a peroxide of K ⁺ , (NH ₄ ) ⁺ or copper salt (or a chloride thereof) as a catalyst in an aqueous solution of metal acrylate. Here, the metal salt of the monomer (or polymer) of acrylic acid dissolves in water, but it is insoluble that these polymers become polymers of the metal salt of acrylic acid again by the force of the catalyst.

On the other hand, the grouting agent of B) uses an acrylamide, which belongs to the organic chemical injection method, and the viscosity of the acrylamide (monomer) is extremely low (about 1.2 CPS), and acrylamide (CH ₂ = CH- In the aqueous solution of CONH ₂ ), a catalyst such as potassium persulfate (K ₂ S ₂ O ₈ ) or ammonium persulfate [(NH ₄ ) ₂ S ₂ O ₈ ] is used. After penetration through the granules, polymer chemistry is used to strengthen the soft soil by the formation of plexiless, water-insoluble soil solids.

However, in the above method, the chemical liquid is lost in the gravel layer below the underground aquifer through which the groundwater flows, and gelation does not occur. In particular, limited injection into a limited area is impossible. That is, this is because the viscosity of the acrylamide monomer penetrates between the granules using a point close to water to solidify a loose bottom layer. This is a known fact well known in the grouting system.

As described above, it is impossible to apply gravel in the underground aquifer, or especially when this groundwater flows, and if the cement mortar grouting is performed in the same way as the conventional method, it may be caused by the deviation of cement particles, which causes failure. Due to the separation of materials and cement pollution, lack of reliability of quality as cement mortar, and limited injection, there are various problems such as uneconomical use such as excessive use of anticipated loss of cement.

Meanwhile, Japanese Laid-Open Patent Publication No. 60-53589 describes the contents of soil stabilized chemical compound and polyacrylate non-acid dust control, which are acrylic acid (co) polymer salt, polybasic acid salt, and water in soil surface layer soil. It relates to stabilizing the surface layer of the soil erosion-resistant and relatively hard without spraying and kneading the mixture dissolved and dissolved in a certain ratio, the method of construction is to spread the surface soil of the soil, spraying, stirring, kneading the electrical compound It is then applied to a roller to stabilize the surface layer or to be consolidated and stabilized by other means.

As another method, an aqueous solution of a monomer of calcium acrylate salt, which is a kind of metal acrylate salt, and a curing accelerator thereof, and a method of hardening and stabilizing the soil surface by the same method using ammonium persulfate, sodium geosulfate-da, etc. have. For your reference, adding a small amount of copper chloride or other copper salts will speed up the curing.

The two methods shown were based on the monomer properties of the metal salt of the acrylic acid monomer (polymer). 1) Monomer of monovalent metal salt (e.g. Na salt) in metal acrylate is well dissolved in water and solidified by acid (PH = 4), and 2) Monomer of divalent metal salt (e.g. Ca salt) in metal acrylate is When water-soluble or polymer becomes, it solidifies in the form of rubber and utilizes the property of being insoluble in water.

However, these are non-homogeneous infiltration between the granules (in the ratio of the amount of treatment used and the amount of soil used), but they are buried under pressure and condensed under pressure, condensing by chemical reactions, not grouting agents, but soil surface treatment agents.

So far, among the acryl-based chemicals of grouting agents, there are acrylamide monomers as organic chemical grouting agents (as described above). However, this is not only a cement mortar, but also the viscosity of the acrylamide monomer is about 1.2 CPS (molecular weight = 86) and is insoluble gelled by the catalyst and used as a reference.

The acrylamide monomer has a specific gravity of about 1.12 and is colorless crystals. The acrylamide monomer is dissolved in water to form an acrylamide aqueous solution. The viscosity of the acrylamide monomer is extremely low at about 1.2 CPS. Thus, a monomer such as water penetrates between granules and sand. Oxidation-reduction of phosphorus persulfate and ammonium persulfate gels together with the granules (or sand) to form a flexible, water-insoluble block that solidifies to increase the bearing capacity of the ground. This is different from the present invention in the physical properties of the starting material, the use of the catalyst, the reaction mechanism, the production material, the purpose of using the grouting agent and the like. Moreover, the grouting of this acrylamide monomer has the following drawbacks.

1) Since this reaction is a reaction using an oxidizing agent and a reducing agent at the same time, the method and the substrate are complicated in injecting and thus the working time becomes long,

2) Because the oxidant is used, various anticorrosive agents needed to prevent oxidation of the injection equipment (eg injection and injection pump) should be additionally used, and the purpose of delaying the reaction (to adjust the injection distance) to control the gelation time. As a result, the high economic burden of using stabilizers also increases.

3) Above all, it is already known in this field that the medicines are lost and cannot be used at all, due to the loss of chemicals in the large air gaps in the underground aquifer, the solidification of the gravel layers, and the grouting in the gravel layers in the moving underground aquifers, which is much worse than the suspended water glass system. It is also a known fact, and the amount of injection is not only economically burdensome, but the deviation of acrylamide monomer is directly related to the pollution problem and is a grouting agent in the use regulation.

Accordingly, an object of the present invention is to solve the above-mentioned various drawbacks, and is characterized by using polymer cement mortar as the injection material.

The present invention inserts a casing pipe by drilling an injection hole in the basement, and expands and forms pores by removing or consolidating earth particles and fine sand mixed in the gravel layer by the surging method, and adding cement and sand, kneaded water and acrylic polymer to the pores. The present invention relates to a polymer cement mortar grouting agent and a method for injecting the same, wherein the cement cement mortar is filled and solidified by mixing a polymer composed of one or two or three kinds of cellulose derivatives and polyethylene oxide.

In the polymer cement mortar according to the present invention, first, the cement mortar is kneaded in accordance with the required strength, and the polymer is added and re-kneaded in a predetermined ratio thereto. Examples of the physical properties required for the polymer added thereto include acrylic polymers as follows:

1) Water soluble and very large molecular weight;

2) the structure of the molecule is straight and long chain;

3) the aqueous solution is viscous (large) and when kneaded in cement mortar, the reaction in water is cohesive to cement particles due to free radicals;

4) The injection device should not be blocked by promoting or quenching the cement mortar by combining with cement during kneading process or pump transfer of mortar, nor should there be any abnormality in the strength of the cured product. It may not be formed or the metal is eluted and incorporated into the injection;

5) Even if polymer cement mortar is injected into the gravel layer in the groundwater layer, material separation does not occur and homogeneity is maintained due to the injection pressure, so that cement mortar adheres to the gravel in the gravel layer so that strength similar to that on the ground should be developed.

The cement mortar to which the polymer is added has good fluidity, and even though it moves to the injection pressure in water, it does not cause material separation of the mortar and is filled and maintained while maintaining a uniform mortar form. It can be expected exactly back.

In the present invention, the acrylic polymer is polyacrylamide or a derivative thereof.

등을 들 수 있고 또한 이들의 중합물도 들 수 있다. 또한 셀룰로스유도체 그리고 폴리에틸렌옥사이드를 사용할 수 있다. 물론 이들의 배합물도 사용할 수 있다. 또한 이 주입한 몰타르 경화물의 초기강도와 장기간에 걸친 강도의 증대를 위하여 탄산칼륨(K₂CO₃)과 마이크로 시리카를 배합하여 사용하면 더욱 효과적이다.

Etc. are mentioned, and these polymerized materials are also mentioned. It is also possible to use cellulose derivatives and polyethylene oxides. Of course, combinations thereof can also be used. In addition, it is more effective to use a mixture of potassium carbonate (K ₂ CO ₃ ) and micro silica in order to increase the initial strength of the injected mortar cured product and the strength over a long period of time.

An injection method using the polymer cement mortar according to the present invention will be described in detail with reference to the drawing as an example of gravel layer grouting.

In Fig. 1, the boring machine 1 drills first, and the casing pipe 2 is inserted. At this time, a strainer 3 of a suitable length is installed at the tip of the casing pipe 2, and the strainer 3 is inserted into the gravel layer. On the gravel surface of the gravel layer 4, a lot of sedimentary deposits are attached, and between the gravel 4, the soil particles or fine yarn 5 is mixed.

In FIG. 2 and FIG. 3, the compressed air is blown into the air compressor 15 through the strainer 3, and the soil particles, fine thread 5, etc. are washed away, and the voids 6 ) Becomes large.

At this time, if the polymer cement mortar 12 'is injected into the gravel layer 4 by lifting the casing pipe 2 into the injection pipe 14, the entire portion (A) forms a concrete block. The injection radius thereof is dependent on the lifting speed of the injection pipe 14 and the injection pressure of the pump 13 which rises according to the lifting speed of the casing pipe 2, and the injection speed is slow, The greater the pressure, the larger the radius of the solidified columnar. When the gravel layer 4 is surging with compressed air, the surface of the gravel is purified and the soil of the pore is consolidated or discharged during surging, thereby increasing the porosity, thereby ensuring the adhesion of the gravel to the polymer cement mortar, thereby obtaining high strength injection solids. In other words, the injected polymer cement mortar and gravel are integrated into concrete.

In the production of polymer cement mortar, the cement (7), sand (8), kneading water (9) are blended as designed and kneaded in the mixer (10), and the polymer aqueous solution (11) is added by a predetermined amount, and the mortar agitator (12) is used. ) Again to form polymer cement mortar (12 '). This is pumped into the pump 13 and injected through the injection pipe 14. This can be injected into the rock layer large void in the same order. The polymer used at this time can use an acryl-type polymer (exhibited polyacrylamide, derivatives thereof, or polymers thereof), cellulose-based, polyethylene oxide and the like.

Referring to the polyacrylamide used in the present invention is as follows.

1. Water-soluble white powder with a molecular weight of 1,000-1,300 × 10 ⁴ , specific gravity being 0.65 by volume (volume) specific gravity; And the larger the molecular weight, the thicker the adhesive layer, the greater the cohesive force.

2. The aqueous solution which melt | dissolved about 0.1-0.3% by weight ratio has the viscosity of 135-1300CPS and PH = 7.5; It is widely known that polyacrylamide has a long chain structure, and it becomes three-dimensionally twisted form and then swells and spreads in an aqueous solution and wraps up cement mortar. ) And economical efficiency is the ratio of cement and water in cement mortar: Cement: Water = 1: 1-1: 10 The amount of polyacrylamide that is usually used is 0.1-0.3% of the weight of cement used in cement mortar. It is used as the aqueous solution converted to and the addition amount of water is adjusted and stirred to adjust the cover ratio so that it may be an optimal condition for injection site as grout agent.

3. The polyacrylamide used at this time is to polymerize the monomer of acrylamide to make a gel, and then dry and pulverize it. If the drying temperature is 60 ° C. or more, the amino group is imide group and becomes insoluble. The same, but be careful.

4. In addition, when using the polymer of polyacrylamide and its derivative (s), it is suitable that the ratio of polyacrylamide and its derivative (s) shall be 0.3-0.7 mol of polyacrylamide.

As described above, the method of the present invention is used alone or 2-3 kinds of polymers such as acrylic polymers (e.g. polyacrylamides) and derivatives thereof (e.g. AMPS), or polymers thereof, cellulose derivatives, polyethylene oxides, and the like. Depending on the injection site, a large amount of macropore in the groundwater or gravel layer with groundwater using polymer cement mortar made by kneading a predetermined amount of aqueous solution of polymer (based on polymer, weight ratio of used cement 0.1-0.3%) as specified in cement mortar. As an injection method to ground, cement mortar is limitedly injected without causing material separation in water, and it is characterized by being economically and safely injected into large pores or gravel layers.

As an embodiment of the present invention, when 0.1-0.3% by weight of an aqueous solution of polyacrylamide is added to the mortar after kneading cement mortar, the viscosity increases at the initial stage of kneading and the fluidity is low. After 3-4 minutes, the polymer cement mortar for injection is extremely good. At this time, the ratio of cement: sand: kneaded water may be mixed on the basis of the strength on the ground, but the amount of kneaded water is pumped by pump (adjusting the amount of kneaded water in consideration of fluidity). Therefore, the cement cement mortar grouting is to cement the gravel layer in the underground aquifer.

Claims (1)

Drill holes in the basement, insert casing pipes, remove earth particles and fine sand mixed in the gravel layer by means of surging to form voids, and add cement, sand, kneaded water and acrylic polymer, cellulose derivatives and polyethylene. A method of injecting polymer cement mortar, characterized by filling and solidifying polymer cement mortar obtained by mixing one or two or three kinds of oxides.

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