JPH09268043A - Lightweight cell grout and its construction method - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To provide an in-situ lightweight bubble grout material capable of obtaining a uniform bubble distribution and a construction method thereof, which is excellent in fluidity when filling a gap between a steel plate and a pier, etc. An object is to make it possible to make the bubble distribution uniform in the height direction without subsequent material separation. The grout material is configured to include cement, mineral powder filler, water, and bubbles having a particle size of 0.1 mm or less.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-situ lightweight bubble grout material that can be uniformly distributed and a method of constructing the same.

[0002]

2. Description of the Related Art Generally, grout materials are used to fill a space between a steel plate and a pier when a pier steel plate winding method is performed as seismic reinforcement work. As a grout material used for this type of application, a bubble inclusion rate of 50 has been conventionally used.
% Air mortar, non-shrink mortar, and mortar shipped from ordinary ready-mixed concrete plants.

In conventional grout materials,
It has the following problems. In the air mortar, as the mortar is injected into the void, the weight of the upper material is applied to the material of the lower portion, the bubbles are crushed, and the material is not uniform. The sand mixed in the non-shrink mortar sinks, causing a difference in specific gravity between the lower part and the upper part, which does not result in a uniform material. In addition, due to the large specific gravity, the lower steel plate may swell due to lateral pressure. In the case of mortar shipped from the ready-mixed plant, it is difficult to obtain fluidity that can be injected into the narrow gap of about 30 mm that occurs between the steel plate and the pier, and special water reducing agents and thickeners are added. Since it must be done, the composition of mortar is complicated, management is difficult, and construction is time-consuming.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of these problems of the prior art. The problem to be solved by the present invention is fluidity when filling a space between a steel plate and a pier or the like. It is an object of the present invention to provide a lightweight cell grout material which is excellent in that there is no material separation after injection and the cell distribution is uniform in the height direction, and a method for constructing the same.

[0005]

Means for Solving the Problems Claim 1 of the present invention
The lightweight cell grout material according to (1) comprises cement, mineral powder filler, water, and cells having a particle size of 0.1 mm or less.

The lightweight bubble grout material according to claim 2 is characterized in that the content of the bubbles is 100 to 500 liters / m ³ .

Further, in the lightweight cellular grout material according to claim 3, the addition amount of the mineral powder filler is 150 to
It is characterized in that it is 350 kg / m ³ .

Further, in the lightweight cellular grout material according to claim 4, the Blaine value of the mineral powder filler is 150.
It is characterized in that it is 0 to 6000 cm ² / g.

Further, in the lightweight cellular grout material according to claim 5, the fluidity of the lightweight cellular grout material is 20 to 5
It is characterized by being 0 seconds.

Further, the method for constructing the lightweight cellular grout material according to claim 6 is the method for constructing a bridge pier steel plate for seismic reinforcement work, wherein cement, mineral powder filler, water, and particle size are provided in the space between the steel plate and the pier. It is characterized in that it is filled with a lightweight bubble grout material consisting of bubbles having a diameter of 0.1 mm or less.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be specifically described. The lightweight cell grout material is composed of cement, mineral filler, water, and cells adjusted to have a predetermined cell particle size in advance.

As the above-mentioned cement, ordinary Portland cement, fast-strength Portland cement, moderate heat Portland cement, blast furnace cement, fly ash cement, jet cement or other ultra-fast-setting cement, alumina-based cement, quick-setting agent, etc. are used to provide fast-setting properties. The cement used is a hydraulic cement such as a cement obtained by adjusting the pot life of the quick-setting cement with a retarder.

As the mineral powder filler, clay,
Natural and artificial mineral powders such as lime, slag, fly ash, silica (silica sand) and alumina are used. Further, the mineral powder filler treated here is usually used after being adjusted in fineness and dried.
The fineness of the mineral powder filler is 1500 as a Blaine value.
~6000cm desirably of about ² / g, more preferably it is of about 3000 ± 200 cm ² / g is used.

[0014] fear this mineral powder degree can cause a risk of larger defective delivery fluidity is lower than 6000 cm ² / g, whereas, the fineness is larger than necessary becomes smaller when breathing than 1500 cm ² / g Because there is. Also, especially, the fineness of the mineral powder filler is 3000
When it is ± 200 cm ² / g, there is an advantage that there is no breathing, an appropriate viscosity is obtained, and the effect of preventing material separation before curing is excellent.

The amount of the mineral powder filler added is about 150 to 350 kg, preferably 200 to 350 g per 1 m ^{3 of} grout material.
It is about 300 kg / m ³ . If the amount of the mineral powder filler added is less than 150 kg / m ³ , the hardened grout material causes material separation, and a uniform grout material cannot be obtained. On the other hand, if the addition amount exceeds 350 kg / m ³ , the necessary strength of the cured grout material may not be obtained.

The lightweight cellular grout material of the present invention further comprises:
Bubbles having a particle size of 0.1 mm or less are mixed with 500 l / m ³ or less, preferably 300 l / m ³ or less. In this case, the lower limit of the amount of bubbles mixed is 100 liter / m ³ . If the particle size of the bubbles exceeds 0.1 mm, the compression amount of the bubbles will increase as the driving height increases, and the homogeneity will be significantly impaired, resulting in problems such as yield management.

When the amount of bubbles mixed in exceeds 500 liters / m ³ , the fluidity is remarkably reduced. This fluidity is more preferable when the amount of bubbles mixed is 300 liters / m ³ or less. On the other hand, if the amount of air bubbles mixed is less than 100 liters, the air bubbles become separated, not only the density is different between the top and bottom of the cast grout material, but the air bubbles gathered at the top form weak areas in terms of strength. Will be
In addition, the desired weight reduction effect cannot be obtained, which is not preferable.

The above-mentioned air bubbles are water-containing air-foaming agents composed of protein derivatives such as gelatin, casein and the like or surfactants (eg Sumishield, trade name, manufactured by Sumitomo Osaka Cement Co., Ltd.) which are usually used in the production of air mortar. It can be produced by diluting with and foaming with a foaming machine (Sumitomo Osaka Cement Co., Ltd.). Bubbles are 10 to 50 times the amount of foaming agent with water,
It is preferably diluted 20 to 30 times, and the expansion ratio is 10 to 60.
Double, preferably 20 to 30 times, to pressurize and foam. Pressurize at the time of foaming with a foaming machine should be 3 atm or more
The pressure is adjusted according to the desired particle size of the bubbles to generate bubbles.
The thus bubble-foamed product can be back-calculated from the bubble weight per unit volume to obtain the average bubble particle size, and the average bubble particle size of 0.1 mm or less is preferably used.
As a method of mixing air bubbles into the mortar, the same method as in the case of adjusting a normal air mortar can be used.

Regarding the fluidity of the grout material, a JA funnel (standard of Japan Society of Civil Engineers) was used, and the flow time elapsed for the grout to flow out from the funnel was measured.
It is desirable that it be 0 to 50 seconds. This is because the flow of grout becomes worse when the flow time is slower than 50 seconds,
Poor delivery can result in voids after curing, and faster than 20 seconds can cause bubbles to be entrapped and breathing to grow larger than necessary.

Further, the lightweight cell grout material of the present invention comprises:
A water reducing agent, water, and other admixtures may be added if necessary. As the water reducing agent, all water reducing agents used for general mortar concrete such as naphthalene-based, melamine-based, polycarboxylic acid-based, and lignin-based can be used, and the amount of the water-reducing agent added is a commonly used addition. The range of quantity.

As other admixtures, for example, when jet cement is used as cement, it is a retarder such as a jet setter for adjusting the pot life, and Portland cements are used as cement. In some cases, an organic thickener or the like is rarely used to prevent breathing, and a defoaming surfactant or the like for eliminating entrapped air is used depending on the type of the water reducing agent used.

As an example of the production of the lightweight cellular grout material of the present invention, the mineral powder filler and the water reducing agent are added to the cement in the above-mentioned addition ratio and premixed, and this mixture is mixed with water and, if necessary, other components. It is manufactured by adding and mixing the mixture material of (1) and kneading, and separately mixing the kneaded material with air bubbles formed by diluting the foaming agent with water and passing through a foaming machine to form fine particles.

As an example of the use of the lightweight cellular grout material of the present invention, in the pier steel plate winding method of seismic reinforcement work,
It is preferably used as a grout material used for filling a space between a steel plate and a pier. In the lightweight cellular grout material applied to the method of rolling up the pier steel plates for this seismic reinforcement work, the particle size of the entrained air bubbles should be as small as 0.1 mm or less, and the amount of entrainment should be 50% or less of the volume of the grout material. By doing so, it is the same as the conventional air mortar in terms of preventing breathing and material separation, but the amount of mixture is much smaller than in the case of air mortar, and collapse of bubbles is eliminated,
The air bubble distribution becomes uniform in the height direction of the pier. For example, when the air bubble content is about 25%, the unit weight is 800 kg / m ³ lighter than non-shrink mortar. Almost no swelling,
The cost is reduced by using the mineral powder filler.

[0024]

Embodiments will be described below. However, the present invention is not limited to only this embodiment. In order to study the bubble particle size and bubble amount for lightweight bubble grout,
Table 2 shows the results obtained by preparing the grout materials prepared from the formulations shown in Table 1 and examining the prepared grout materials for fluidity, strength, breathing, presence or absence of collapse of bubbles, and swelling of the steel sheet.
Here, the swelling of the steel sheet means a 700 mm square cross section and a height of 5 m.
This is the swelling of the steel plate when a steel plate is wound around the RC column with a clearance of about 30 mm and a grout material is injected into the clearance. Further, in order to examine the content of the mineral powder filler (stone powder) in the proper bubble particle size, the mixture was prepared according to the composition shown in Table 3, and for each of the prepared grout materials, fluidity, strength, breathing, and bubble collapse were prepared. Table 4 shows the results of examining the presence or absence of swelling and the swelling of the steel sheet.
Shown in Furthermore, in order to study the Blaine value of the mineral powder filler at an appropriate bubble particle size, the mixture was prepared according to the formulation shown in Table 5, and for each of the prepared grout materials, fluidity, strength, breathing, and presence or absence of collapse of bubbles were examined. Table 6 shows the results of examining the swelling of the steel sheet.

Here, the fluidity is the method of JSCE standard (J
A funnel). The strength was measured by measuring the uniaxial compressive strength of a cylindrical specimen (diameter 50 mm, length 100 mm) of 28 days old. Breathing was examined according to the standards of the Japan Society of Civil Engineers. The presence or absence of collapse of bubbles was evaluated by microscopic observation of the cross section of the cured product after injection. The swelling of the steel sheet was visually observed.

[0026]

[Table 1]

[0027]

[Table 2]

[0028]

[Table 3]

[0029]

[Table 4]

[0030]

[Table 5]

[0031]

[Table 6]

As is clear from the results of Tables 1 and 2, the grout materials of Examples 1 to 6 have excellent fluidity on the order of 20 to 50 seconds, and the grout materials of Comparative Examples 1 to 7 are excellent. The uniaxial compressive strength is comparable to that of the material, and in particular, the strength is higher than that of the air mortar of Comparative Example 1, and the breathing rate is improved to almost "0" value. By observing the cross section of the body, the collapse of air bubbles was reduced and the swelling of the steel sheet was also reduced.

From Tables 3 and 4 above, Examples 1 to 5 were obtained.
Indicates that the content of the appropriate mineral powder filler (stone powder) when the bubble particle size is 0.04 mm is in the range of 150 to 350 kg / m ³ . Comparative Example 1, when the content of mineral filler powder is 100 kg / m ^3, can not be molded specimen causing material separation, in which a strength untestable. Further, in Comparative Example 2, when the content of the mineral powder filler is 400 kg / m ³ , the fluidity is deteriorated to the extent that it does not flow due to clogging in the pressure-feeding flow passage.

From Tables 5 and 6 above, Examples 1 to 3
Shows that the proper Blaine value of the mineral powder filler when the bubble particle size is 0.04 mm is in the range of 1500 to 6000 cm ² / g. In Comparative Example 1, when the Blaine value of the mineral powder filler was 1000 cm ² / g, the test piece could not be formed by causing material separation, and the strength test was impossible. Further, in Comparative Example 2, when the Blaine value of the mineral powder filler is 8000 cm ² / g, the fluidity and the material separation resistance are deteriorated to such an extent that the filler does not flow due to the pressure feed channel.

[0035]

As described above, the lightweight cellular grout material according to claim 1 of the present invention is composed of cement, mineral powder filler, water, and bubbles having a particle size of 0.1 mm or less. As a grout material to be injected into the gap created between the bridge pier and the steel plate in the winding method, it has appropriate fluidity, eliminates breathing, prevents material separation, and maintains shape stability. Smaller size reduces swelling of steel sheet.

Further, in the lightweight foam grout material according to claim 2, since the content of bubbles is 100 to 500 liters / m ³ , the bubble content is much smaller than that of the air mortar, and the bubbles collapse. On the other hand, the specific gravity becomes smaller than that of the conventional grout material, and the swelling of the steel sheet due to the injected grout material can be reduced.

Further, in the lightweight cellular grout material according to claim 3, the amount of the mineral powder filler added is 150 to 350 kg /
By set to m ^3, to improve the shape stability prevents the material separated to maintain the interface with the bubble, to reduce the swelling of the steel sheet by grout injected to reduce the specific gravity than the conventional grout that Moreover, the cost can be reduced by using the mineral powder filler.

Further, in the lightweight cellular grout material according to claim 4, the Blaine value of the mineral powder filler is 1500 to 600.
By setting it to 0 cm ² / g, there is almost no breathing, the interface with bubbles is better maintained, the shape stability is effectively maintained, and the material until the hardening occurs in the conventional grout material. Separation can be prevented and material properties after curing are remarkably excellent.

In addition, in the lightweight cellular grout material according to claim 5, since the fluidity is set to 20 to 50 seconds, the grout can be cast in-situ in the space between the steel plate and the pier in the pier steel plate winding method of seismic reinforcement work. It has excellent fluidity,
The workability in seismic reinforcement work is improved, and the construction period and cost can be reduced.

Further, in the method for constructing a lightweight cellular grout material according to claim 6, in the method of winding up the pier steel plate for seismic reinforcement work, the space between the steel plate and the pier is filled with cement, mineral powder filler, water and particle size. By filling with lightweight bubble grout material consisting of bubbles of 0.1 mm or less, breathing and material separation are prevented, the distribution of bubbles mixed in the grout material becomes uniform in the pier height direction, and the lateral pressure of the injected grout material is increased. This will prevent the steel sheet from swelling and solve the most important problem in seismic reinforcement work.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location C04B 24:14) 103: 48 111: 70 (72) Inventor Kaoru Kurita Benten, Chuo-ku, Chiba City, Chiba Prefecture 580, Machi Totetsu Kogyo Co., Ltd., Chiba Branch (72) Inventor, Noriyuki Kosakai, 1 Kami Midoshiro-cho, Chiyoda-ku, Tokyo Sumitomo Osaka Cement Co., Ltd. (72) Inventor, Kenji Takemoto 585 Minami-cho, Funabashi, Chiba Prefecture Address Sumitomo Osaka Cement Co., Ltd. (72) Inventor Masahiro Yoshihara 585 Tomimachi, Funabashi City, Chiba Sumitomo Osaka Cement Co., Ltd. Central Research Laboratory (72) Inventor Sayuri Tojo, 585 Tomimachi, Funabashi, Chiba Sumitomo Osaka C Central Research Institute, Mento Co., Ltd.

Claims (6)

[Claims] 1. A lightweight bubble grout material comprising cement, a mineral powder filler, water, and bubbles having a particle size of 0.1 mm or less. 2. The lightweight bubble grout material according to claim 1, wherein the content of the bubbles is 100 to 500 liter / m ³ . 3. The amount of the mineral powder filler added is 150
The lightweight cell grout material according to claim 1 or 2, wherein the weight is about 350 kg / m ³ . 4. The Blaine value of the mineral powder filler is 1
It is 500-6000 cm < ² > / g, The lightweight bubble grout material of Claim 1 or 2 characterized by the above-mentioned. 5. The fluidity of the lightweight cellular grout material is from 20 to
The lightweight cell grout material according to claim 1 or 2, wherein the material is 50 seconds. 6. A lightweight aerated grout material consisting of cement, mineral powder filler, water and bubbles with a particle size of 0.1 mm or less is filled in the gap between the steel plate and the pier in the method of rolling up the pier steel plate for seismic reinforcement work. A method for constructing a lightweight bubble grout material characterized by: