JPH01318080A - Grout and underground formation of cured object by using the same grout - Google Patents

Abstract

PURPOSE:To obtain a grout improved in flow so as to be pumped from the ground by mixing a cement with calcium silicate hydrate powder, a fine aggregate and mixing water. CONSTITUTION:A calcium material, a silicic material, etc., are subjected to a hydration reaction, followed by atmospheric pressure steam curing, a high- temperature high-pressure steam curing, etc., and ground to obtain a calcium silicate hydrate powder (A) of a particle diameter of 1mm or below, represented by the formula (wherein X, Y and Z are positive integers). 100 pts.wt. cement (B) (e.g., portland cement) is mixed with 150-250 pts.wt. component A, 200-500 pts.wt. fine aggregate (C), and 70-110wt.%, based on the total amount of components A and B, mixing water to obtain a grout. Said grout is pumped from the ground into a water-permeable bag inserted into the ground, whereupon said bag is expanded while excessive water is removed from the grout to form an underground cured object.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a grout material used in the construction of piles used in constructing the foundations of architectural structures on soft ground, and The present invention relates to a method for producing a cured body.

(Prior Art and Problems) Conventionally, it is known from JP-A-58-173183 to use cement calcium silicate hydrate powder as a grouting material. However, in order to use this grout material without pleating and within the desired compressive strength range, the amount of water etc. used must be limited, and within the range where the amount of water etc. used is limited, the fluidity will be low. It wasn't very good.

Also, if you increase the amount of water used to increase fluidity,
There were drawbacks such as compressive strength being less than xoJcff/cd, resulting in a significant decrease in strength. Therefore, in order to use this grout material within the desired strength range, injection pipes and the like were required.

On the other hand, JP-A-58-156620 discloses using concrete as a grout material and injecting it into the bag body, but concrete does not have very good fluidity when poured without separating the materials, for example. If an attempt is made to inject into the bag without using an injection tube that reaches the bottom of the bag, it will only be possible to inject into the top of the bag, and the bottom of the bag cannot be expected to expand and expand due to filling with injection material. Therefore, in order to pour concrete to the bottom of the bag,
It was necessary to use an injection pipe that reached the bottom of the bag and pour concrete into the bag while pulling up the injection pipe.

Furthermore, JP-A-61-165412 discloses using coal ash as a grout material and injecting it into the bag; The fluidity is poor within the range in which the desired compressive strength can be obtained, and as shown in the procedural amendment shown in JP-A No. 61-165412, an injection tube that reaches the bottom of the bag is still used. In addition, Japanese Patent Application Laid-open No. 137912/1983 discloses that cement mortar can be used as a grout to be injected into the bag. However, if the amount of sand is increased without causing pleating and within the desired strength range, the fluidity will deteriorate. The reality is that mortar is used whose weight is less than twice the weight of cement. Therefore, this mortar uses a large amount of cement (unit amount of cement) in the hardened body, making it an expensive grout material.

In this way, 1- For boat fishing, there is no need to use an injection pipe that reaches the bottom of the bag, and the grout used when injecting into the bag uses a large amount of cement (unit amount of cement) in the hardened material. , is an expensive grout material. That is, conventional grouting materials with high fluidity are expensive, and other grouting materials do not have such high fluidity and require long injection pipes for injection.

(Means for Solving the Problems) The present invention was made to solve the above-mentioned drawbacks of the prior art, and its purpose is to provide a grout material that has good fluidity, can be pumped from above ground, and is inexpensive. In addition, the present invention provides a simple and economical method for creating a geothermal hardened body using a water-permeable bag.

The present invention provides (1) a system mainly consisting of cement, calcium silicate hydrate powder, fine aggregate, and mixed water, in which the calcium silicate hydrate powder is 150~250 parts by weight, fine aggregate 200~SOO''
(2) cement, calcium silicate water; powder, fine aggregate, and mixed water? The system consists mainly of calcium silicate hydrate powder in an amount of 150 to 250 parts by weight per 100 parts by weight of cement.
M pear part, a water-permeable bag in which a grout material containing 220 to 500 ffiJt of fine aggregate and 70 to 110% by weight of blended water based on the total amount of cement and calcium silicate hydrate powder is inserted into the ground. A hardened body underground using a grout material, characterized in that a pump is press-fitted from the ground into the grout material, the bag body is expanded and expanded, and surplus water of the grout material is dehydrated, and a hardened body is created underground. This is the creation method. .

The cement used for the grout material of the present invention is Portland cement, blast furnace cement, ply ash cement,
Alumina cement, etc., and Portland cement is usually used. In this case, unit cement amount (hardened material I
The amount of cement used when making I is expressed in 4/m3. ) is 2501'v to improve economy.
/nl" or less is preferable.

The grout material of the present invention is characterized by the use of calcium silicate hydrate powder together with fine aggregate, making it an inexpensive grout material with good pourability.

The calcium silicate hydrate used in the present invention is
-Y(SiO)-Z (consists of the composition of H2O (where X, Y, and Z are positive integers). Calcium silicate hydrate is produced by combining calcium raw materials, silicic raw materials, etc. It is produced by normal-pressure steam curing treatment, high-temperature and high-pressure steam curing treatment, etc. Examples of molded bodies of calcium silicate hydrate include calcium silicate-based heat insulating materials, lightweight cellular concrete, and silica bricks. Examples include.

When using these products, one or two of these molded products may be used.
It is preferable to grind the seeds or more with a ball mill, rod mill, etc. and use them as a powder. At this time, it is preferable to crush the powder so that the particle size is 1 mm or less. Particularly preferably, the particle size is distributed in the range of 100 to 500 microns (0.1 to 0.5 millimeters), considering the power and time required for powdering and the injection performance of the resulting grout material. .

Incidentally, the calcium silicate hydrate may be used in the form of a powder or the like from the beginning instead of being formed into a molded body.

The above calcium silicate hydrate powder can be evenly distributed in the water in the grout, increase the viscosity of the grout, prevent material separation and pleating of the grout, and allow the grout to be pumped by pumping. The material flows smoothly.

In addition, in the field of application of the present invention, the compressive strength required for the obtained cured product is usually 30! '/- is sufficient. In the underground preparation method for a hardened body of the present invention, surplus water in the grout material is dehydrated using a bag, so the compressive strength of the grout material of the present invention during use may be low (that is, the compressive strength of the grout material of the present invention may be low). The compressive strength of the entire grout material when cured as it is may be about 10 Kqf/ctA). Therefore, Seme;
') A large amount of calcium silicate hydrate can be used in the range of 150 to 250 parts by weight per 100 parts by weight. If a large amount of water is added, material separation and pleating will occur, and the pumpability will be significantly reduced (see table 1, column 1 below). If the amount exceeds 250 parts by weight, the viscosity of the grout increases too much, the application speed decreases, and it becomes impossible to obtain the desired strength (see Table 1 below).
(see Nl15).

Further, the fine aggregate is one used in normal mortar, concrete, etc., such as river sand and crushed sand. The amount of fine aggregate used is in the range of 200 to 500 parts by weight per 100 parts by weight of cement. If the amount is less than 200 parts by weight, calcium silicate hydrate is used, so the viscosity of the grout increases too much, the application speed decreases, and the amount of cement per unit increases, resulting in an expensive grout (see below). Table of -
(See part 2 of 3). If the amount exceeds 500 parts by weight, the proportion of fine aggregate in the grout increases, and conversely, the proportion of cement and calcium silicate hydrate becomes relatively small, resulting in material separation and poor fluidity. (See order 7 in Table 3 below). Note that the particularly preferable amount of fine aggregate used is 300 to 400 parts by weight, and the optimum amount is around 400 parts by weight.

Next, the proportion of mixed water should be such that the grout material can flow as described above, and can be determined from the compressive strength of the grout material and the pumpability. That is, 70 to 110% by weight based on the total amount of cement and calcium silicate hydrate powder.
is within the range of If the amount of water added is less than 70% by weight, the viscosity of the grout material increases too much and the application speed decreases (see N11l in Table 2 below). Moreover, if it exceeds 110% by weight, material separation may occur in the grout material, making it impossible to pump the pump or causing the compressive strength to become too low (see item 5 of Table 2 below).

The particularly preferable amount of blended water used is 80 to 100% by weight.
It is.

As explained above, the grout material of the present invention is a system mainly composed of cement, calcium silicate hydrate powder, fine aggregate, and mixed water. , fine aggregate, and mixed water, or may contain other admixtures in combination without departing from the purpose of the grout material of the present invention.

The grout material of the present invention having the above configuration has a flow value of 15 seconds or less and a breathing rate of 2 inches or less, and is an inexpensive grout material with good pourability. Furthermore, the cured body obtained by the underground preparation method for a cured body of the present invention using this grout material has a hardness of 30 to
It satisfies a predetermined compressive strength of crI.

The bag used in the underground construction method for a cured product of the present invention is a water-permeable bag. As the material of the bag, common fiber materials such as synthetic fibers such as polyester, polypropylene, and polyethylene are used. In addition, the bag material is based on the high-pressure injection conditions (5 to 1
5 to f/-) K Sufficient tensile strength (about 5 f/-)
It is more preferable that the total amount is 0 to 1000 (about 9 f/-), and in particular, synthetic fibers are used. Furthermore, it is highly desirable to use these materials to create a fabric that has sufficient eyelets to dehydrate excess water in the grout material.

Next, the method for creating a cured body underground according to the present invention will be explained using a specific example shown in the drawings.

As shown in Fig. 1(a), a drilled hole 1 with a predetermined diameter or less
A water-permeable bag 2 is inserted into the bag. If the ground is quite soft, it is also possible to grasp the tip of the bag with the tip of the shaft and push it directly into the ground. Pre-drilled hole 1
The diameter of the excavation when inserting the bag 2 is sufficient as long as the bag can be easily inserted into the excavation diameter, and normally, it is sufficient that the excavation diameter is about half the outer diameter of the bag.

Next, as shown in FIG. 1(b), grout material 4 is injected into the inside of the stake bag body 2. The injection method is by press-fitting the bag body 2 from the upper open end with a pump. This method is the simplest, quickest, and most economical. In this way, the pressurized injection of grout into the water-permeable bag progresses, excess water is effectively dewatered, and eventually, as shown in Figure 1 (CC), A large cured body 6 is formed.

(Example) The present invention will be described below with reference to Examples, but the present invention is not limited to these K in any way.

In addition, in the Examples and Comparative Examples, tests to examine the characteristics of the grout materials were conducted by the following method.

B) P-funnel flow test The grout material after kneading was immediately filled into the P-funnel, and the time taken for the entire amount to pass through the bottom was measured as a flow value.

(b) Breathing rate test According to the Japan Society of Civil Engineers ``Test method for breathing rate and expansion rate of pouring mortar for pre-concrete concrete'', the polyethylene bag was filled 3 minutes after the start of crosstalk, and left to stand for 3 hours. The volume ratio of the amount of upper floating water to the total volume was measured as the pleating rate.

(c) Compressive strength test Measurement was performed in accordance with JIS-R-5201.

In addition, the grout materials used in the Examples and Comparative Examples were ordinary Portland 9 cement as the cement and pulverized lightweight cellular concrete cured with high temperature and high pressure steam as the calcium silicate hydrate with a particle size in the range of 100 to 500 microns. , as a fine aggregate,! 2.65 gold dust was used.

Example 1 and Comparative Example 1 To 100 tft of cement, 400 parts of fine aggregate, 150.200.250 parts of calcium silicate hydrate, and water were added to the mixture of cement and calcium silicate hydrate. In order to keep the total amount constant (approximately 85% by weight), 210, 260, and 300 parts by weight were prepared and kneaded.7 For comparison, the same amount of cement fine aggregate as in the example was prepared. Calcium silicate hydrate, 100.300
Parts by weight were added, and water was added in the same proportion as in the example, and the mixture was kneaded. The flow value, breathing rate, and compressive strength of the grout material obtained by these methods were measured. The results are shown in Table-1.

It can be seen that although the flow value is almost the same for Takis 1 to 5, the breathing rate is 2 seconds or less for Takis 2 to 5 due to the water retention effect of calcium silicate hydrate, which indicates that material separation is excellent. In terms of strength, it is OKpf from ItL1 to ItL4.
/d or more, but in Seed 5, the unit cement amount was small (less than 10K4/-).

Example 2 and Comparative Example 2 To 100 parts of cement, 400 parts by weight of fine aggregate, 200 parts by weight of calcium silicate hydrate, and further water to the total amount of cement and calcium silicate hydrate. , 70
, 90, and 110 weights were prepared and kneaded respectively. 2. For comparison, the same cement, fine aggregate, and calcium silicate hydrate as in the example were prepared, and water was further added to the cement and calcium silicate hydrate. The flow value, breathing rate, and compressive strength of the grout materials obtained were measured. The results are shown in Table-2.

In terms of flow value, it takes less than 15 seconds for Na2 to Na5, and it can be said that it is a grout with good fluidity.However, Nl11 uses a small amount of water, making crosstalk difficult, and the resulting product has a high viscosity, so the total amount could not pass through the P roto. In terms of Pleasin/Rate, the time was still 2 seconds or less for 1 to 4, and the material separation resistance was good, but 5 had a lot of water and was easy to separate.

In addition, the compressive strength is 10 Kpf/i or more for la1 to la4, which is a predetermined value, but for Na5 it is 1 OKf/i.
/d.

In this way, Ugly 2 to 4 in Table 1-2 are Example 2, and Ugly 1 is Example 1.
and No. 5 are Comparative Example 2.

Example 3 and Comparative Example 3 100 parts by weight of cement) K, 200 parts by weight of calcium silicate water, water at a constant amount of 85 parts per 9 parts of the total amount of cement and calcium silicate hydrate, and 200, 300, 400, and 500 parts by weight of fine aggregate were prepared and mixed into wires.

For comparison, cement, calcium silicate hydrate, and water were prepared in the same proportions as in Example 3, and the samples were prepared without using fine aggregate, and with 100 parts by weight and 600 parts by weight of fine aggregate. , were kneaded, respectively.

The 70-value, pleating ratio, and compressive strength of these grout materials were all measured1, and the results are shown in Table 3.

The flow value is less than 15 seconds from m3 to m7, and the grout material has good fluidity.
The value exceeded seconds.

The pleating rate was 2 inches or less for Falls 1 to 6, and the material separation resistance was good, but in NIIL7, the proportion of fine aggregate was high and it was easy to separate.

The compressive strength is 10% flai or more for floors 3 to 7, but the strength decreases for floors 1 and Na2.

In this way, 凰3 to 6 in Table 3 are Example 3, and No. 1
and No. 2 and No. 7 are Comparative Example 3.

Margin Example 4: Inner diameter when expanded is 300 mm and length is 5000 mm
A bag consisting of a cloth of polypropylene tape yarn of
0 mm, depth of 5000 mm, and the grout material having the weakest strength among the examples shown in Table 2 m41c was injected into the bag up to the depth of the bag. Approximately 10Ky/all by press-fitting from the ground surface without insertion
When the pressure of 360 liters was reached, the predetermined amount of grout, approximately 360 liters, could be injected, so the injection was completed and the creation of a hardened body was completed. After 7 days of curing, an excavation survey was conducted to determine the shape and dimensions of the hardened body. The compressive strength of the core sample at both ends and the center was measured.

As a result, the shape of the cured body was a perfect cylinder with a length of 300 to 320 mm over almost the entire length. In addition, the compressive strength is 30~30 for both ends and the center.
It had a nearly uniform strength of 40 Kff/i, and had sufficient performance as an antibody.

Comparative Example 4 Instead of the grout material used in Example 4, the above Table-1
A cured body was prepared in the same manner as in Example 4 using the 0 Arashi 5 grout. The results showed that the injectability was good, but the compressive strength of the obtained core sample was around 20 Fgf/ff1 at both ends and the center, which was less than the predetermined value of 30 K4f/d required for a cured product. However, the performance as an antibody was unsatisfactory.

Comparative Example 5 A cured product was prepared in the same manner as in Example 4, using the N17 grout of Coat-3 in place of the grout used in the actual test. As a result, the pressure suddenly rose after injecting about 100 liters, and the maximum pressure was 20K.
g/ffl, the pressure suddenly decreased and the final injection amount was about 150 + J liters. When this was excavated and investigated, it was found that almost no water had been injected deeper than about 2 meters below ground level, and moreover, the bag had burst near the ground level.

As can be seen from Table 3, this grout material has a precipitating rate of over 2 seconds, and when poured, m of the material was produced, creating a plug-like condition at the top of the bag. It was confirmed that this grout material had poor pourability.

(Effects of the Invention) The grout material of the present invention is a grout material that can considerably reduce the amount of cement used, is inexpensive, and has good fluidity with less material separation. This grout material, which exhibits good properties, can be pumped from above ground into permeable bags underground. Further, the cured body produced by such a method for producing a cured body has sufficient strength, and can be easily constructed and economically obtained.

[Brief explanation of the drawing]

'41 Figure (a), Figure 1 (b) and Figure 1 (C) are
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a process diagram illustrating the method for creating a hardened body underground according to the present invention in order of steps. In the figure; 1 is an excavation hole, 2 is a water-permeable bag body, 3 is an upper open end, 4 is a grout material, 5 is an injection hose, and 61-j shows a hardened body. Patent applicant Asahi Kasei Industries Co., Ltd. No. 11!1

Claims (1)

[Claims] (1) A system mainly consisting of cement, calcium silicate hydrate powder, fine aggregate, and mixed water, with cement 10
Calcium silicate hydrate powder is 150 parts by weight.
-250 parts by weight of fine aggregate, 200 to 500 parts by weight of fine aggregate, and 70 to 110% by weight of blended water based on the total amount of cement and calcium silicate hydrate powder. Material (2) A system mainly consisting of cement, calcium silicate hydrate powder, fine aggregate, and mixed water, with 150 to 250 parts of calcium silicate hydrate powder per 100 parts by weight of cement. Weight part, fine aggregate 200
~500% by weight, and further blended water by 70 to 110% by weight based on the total amount of cement and calcium silicate hydrate powder.
The grout material contained in the grout material is pumped from above ground into a water-permeable bag inserted into the ground, and while the bag expands and expands, surplus water from the grout material is removed to form a hardened body underground. Method for creating a hardened body underground using grout material