JP2003119066A - Self-filling mortar composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mortar composition which has a reduced quantity of heat of hydration, and has self-filling property. SOLUTION: The self-filling mortar composition is obtained by blending a 100 to 200 pts. fine aggregate containing a cement material and 50 to 90% limestone fine powder having a Blaine specific surface area of >=3,500 cm<2> /g, and further adding a gas foaming material and/or a carbonization material and a fluidization agent thereto, and in which the content of 3CaO.SiO2 as the cement material is >=60%. The self-packing mortar composition further contains an expansion material, silica fine powder, and a thickener. The compressive strength in an age of 28 days of the self-filling mortar is preferably <=35 N/mm<2> .

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention mainly relates to a self-filling mortar composition used in the field of civil engineering and construction. In the present invention, parts and percentages indicating the amounts used, contents, blending ratios and the like used in the present invention are mass units unless otherwise specified.

[0002]

2. Description of the Related Art Conventionally, a mortar composition having a self-filling property is generally called a grout material. As a cement admixture for grout, a mixture containing an expansive material and a water reducing agent as main components has been proposed. (JP-A-53-13650, JP-A-53-31170, etc.). The grout material containing these is excellent in workability and filling property and is used as a material for smoothly completing the grout work. The important physical properties required for grout materials are that they are non-shrinkable, that they have good flowability and that they retain well,
Recently, there is a tendency for a large number of constructions to be installed, and prevention of temperature cracks due to heat of hydration is also required, and it is required to satisfy all of these physical properties.

[0003]

However, many of the conventional grout materials aim at high durability and are designed so that the amount of unit cement used inevitably increases. Therefore, in the summer, Not only was the time to ensure good fluidity short, but the calorific value of hydration and self-contraction also increased, and considerable time and cost were required to carry out sufficient construction. On the other hand, if a large amount of water-reducing agent or fluidizing agent is mixed in order to secure the fluidity, the variation of the setting property due to the change of the working environment temperature may become large, and it may be difficult to exhibit stable properties. It was In addition, depending on the construction site, high strength is often not required, and development of a mortar composition that has a small amount of heat of hydration and is excellent in self-filling property has been awaited. In view of these problems, the present inventors have completed the present invention by finding that the above problems can be solved by a specific self-filling mortar composition.

[0004]

That is, the present invention provides a limestone fine powder having a Blaine specific surface area of 3500 cm ² / g or more.
A self-filling mortar composition obtained by blending fine aggregate into a limestone cement consisting of 0 to 90% of a cement substance and limestone fine powder, and further adding a gas foaming substance and / or a carbonizing substance and a fluidizing agent. , 3CaO of cement material
The self-filling mortar composition has a SiO ₂ content of 60% or more, and further contains an expanding material, a siliceous fine powder and a thickener. Further, it is preferable that the self-filling mortar composition has a compressive strength of 35 N / mm ² or less at 28 days of age.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.

The cement material used in the present invention means 3C
aO ・ Al ₂ O ₃ , 4CaO ・ Al ₂ O ₃・ Fe ₂ O ₃ , 2C
aO-· SiO ₂ and 3CaO · SiO _2, and anhydrous, a hemihydrate, and dihydrate gypsum major component, the proportion of the components but is not particularly limited, 3C Among these components
The aO.SiO ₂ content is preferably 60% or more. Commercially available low-heat, moderate-heat, normal, early-strength and ultra-fast-strength cements can be used. Among them, it is preferable to use fast-strength or ultra-rapid-strength cement in terms of good initial strength development.

The fine limestone powder used in the present invention is obtained by crushing limestone and has a Blaine specific surface area of 3500 cm ² / g or more. 3500 cm ² /
If it is less than g, material separation or subsidence phenomenon may be observed. The amount of fine limestone powder used is 100 parts of limestone cement consisting of cement material and fine limestone powder,
50 to 90 parts are preferable, and 60 to 80 parts are more preferable. If it is less than 50 parts, it may not be excellent in fluidity retention and reduction in heat of hydration, and if it exceeds 90 parts, curing may be slow and the mold may be broken.

The fine aggregate used in the present invention may be, for example, lime sand, silica sand, river sand, sea sand, mountain sand, crushed sand, etc., and the maximum particle size is preferably 5 mm or less, more preferably 2.5 mm or less. preferable. The amount of fine aggregate used is preferably 100 to 200 parts per 100 parts of limestone cement.

The gas foaming substance used in the present invention is a substance that releases gas when it comes into contact with water or alkaline water,
It is intended to stabilize the initial size of the grout material. Examples thereof include metal powders such as zinc, iron, and aluminum powders, peroxide substances such as potassium persulfate and sodium perborate, and calcium silicate. Metal powder is used for the purpose of antioxidant, vegetable oil, animal oil, mineral oil, stearic acid,
Those surface-treated with alkanolamines and glycols such as ethylene glycol and diethylene glycol can also be used. The amount of the gas foaming substance used is preferably 0.001 to 1 part with respect to 100 parts of limestone cement.

The carbonized material used in the present invention stabilizes the initial size of the grout material, and examples thereof include fluid coke, coal coke, petroleum coke and carbon black. The amount of the carbonized material used is preferably 1 to 10 parts based on 100 parts of limestone cement.

The fluidizing agent used in the present invention improves the fluidity of the grout agent, and is called, for example, a commonly used water reducing agent, AE water reducing agent, high performance water reducing agent, or high performance AE water reducing agent. It is possible to use any of the above, specifically, a polyalkylallyl sulfonate condensate system, a melamine sulfonate condensate system, a lignin sulfonate system, a naphthalene sulfonate system, a polycarboxylic acid system, an oxy system. One or more of carboxylic acid salts and amino sulfonic acid can be used. The fluidizing agent is preferably used in an amount of 0.01 to 3 parts in terms of solid content with respect to 100 parts of limestone cement.

The expansive material used in the present invention is a material that reacts with water to expand and stabilize the size of the grout material.
For example, commercially available calcium sulphoaluminate-based and lime-based expansive materials can be used, and specifically, quick lime, quick lime, and alite, calcium aluminoferrite, calcium ferrite, auin, calcium fluoride, and anhydrous gypsum. The minerals containing one or more of the above minerals as main minerals. The expansive material is preferably used in an amount of 1 to 10 parts based on 100 parts of limestone cement.

The siliceous fine powder used in the present invention improves the resistance to material separation of the grout material.
For example, silica fume and fly ash can be used. The amount of fine silica powder used is 100 limestone cement.
It is preferably 3 to 30 parts with respect to parts.

The thickener used in the present invention improves the resistance of the grout material to material separation. For example, methyl cellulose, carboxymethyl cellulose, cellulose ether such as cellulose ether, polyethylene oxide, polypropylene oxide, polybutylene. Polymers such as oxides, acrylic polymers whose main component is a copolymer of acrylic acid, methacrylic acid and ester can be used. The amount of the thickener used is preferably 0.01 to 1 part with respect to 100 parts of limestone cement.

In the present invention, a hydraulic substance, fine limestone powder,
Fine aggregates, expanders, carbonized substances, gas foaming substances and thickeners, as well as set accelerators, set retarders, AE agents, cement hardeners, rust inhibitors, polymer emulsions, clays such as bentonite and montmorillonite. 1 of minerals, inorganic phosphate, etc.
It is possible to use one kind or two or more kinds in combination as long as the object of the present invention is not substantially impaired.

Water / self-filling mortar composition of the invention
Cement composition ratio (here, the cement composition is the self-filling mortar composition minus the fine aggregate.
The same applies hereinafter. ) Is not particularly limited, but is 25
About 45% is preferable.

The self-filling mortar composition of the present invention preferably has a compressive strength of 35 N / mm ² or less at a 28-day-old age in view of the heat of hydration and self-filling property.

The self-filling mortar composition of the present invention can be prepared by mixing the respective components in advance or by mixing the respective components immediately before use. Any agitation device can be used, for example tilting barrel mixers, omni mixers, V-type mixers,
Henschel mixer, Nauta mixer, etc. can be used. For the mixing, the respective materials may be mixed at the time of construction, or a part or all of them may be mixed in advance. The mixing order is not particularly limited.

[0019]

The present invention will be described in detail below based on experimental examples.

Experimental Example 1 For 100 parts of limestone cement in the amount shown in Table 1, 0.01 part of gas foaming material A, 5 parts of carbonized material a, 5 parts of expansive material,
A mortar composition was prepared by using 10 parts of silica fine powder (i) and 0.1 part of a thickener (a), and further mixing 100 parts of limestone cement with the amount of fine aggregate shown in Table 1. Also, the water / cement composition ratio and the amount of fluidizing agent were adjusted so that bleeding water was not generated as much as possible, and the mortar flow immediately after kneading was 240 ± 5 mm. And the compressive strength was measured. The casting temperature is 20 ° C. The results are shown in Table 1.

<Materials used> Cement material: Commercial early-strength Portland cement Cement material: Commercial ordinary Portland cement Limestone fine powder: Aomi Kurohimeyama, Niigata prefecture, Blaine specific surface area 6000 cm ² / g Fine aggregate: Himekawa, Niigata table Dry sand, specific gravity 2.62 g / cm
³ Gas foaming substance A: Commercial product, aluminum powder carbonized substance a: Fluid coke expansion material: Commercial product, CSA expansion material, Blaine specific surface area 5
900 cm ² / g Silica fine powder a: Tohoku Denryoku fly ash thickener (a): commercial product, methylcellulose superplasticizer: commercial product, polycarboxylic acid type

<Measurement Method> Flow Retention: The flow value was evaluated by the change with time. JIS
According to the flow test of R 5201, the flow values were measured immediately after kneading and after 30 minutes by no tapping. Adiabatic temperature rise value: An adiabatic temperature rise measuring device manufactured by Tokyo Riko Co., Ltd., which puts an insulating pot with a sample volume of 0.01 m ³ into a small greenhouse and controls it so that the mortar temperature and the greenhouse temperature are always the same. Was measured under the conditions of a casting temperature of 20 ° C. Rate of change in length: Measured at a material age of 28 days according to JIS A6202. Compressive strength: Measured using a pressure resistant device on a cylindrical specimen with a diameter of 50 mm and a height of 100 mm.

[0023]

[Table 1]

From Table 1, it can be seen that according to the present invention, a self-filling mortar composition having excellent fluidity-retaining property, low heat of hydration and low shrinkage can be obtained.

Experimental Example 2 For 100 parts of limestone cement consisting of 30 parts of cement material and 70 parts of limestone fine powder, the amount and kind of gas foaming material, carbonized material and expansive material shown in Table 1 and siliceous fine powder Using 10 parts and 0.1 part of a thickener (a), 100 parts of limestone cement was further mixed with 100 parts of fine aggregate to obtain a mortar composition. Water / cement composition ratio 30%
For the mortar whose mortar flow immediately after kneading was adjusted to 240 ± 5 mm using the amount of the fluidizing agent,
A test was performed in the same manner as in Experimental Example 1 except that the flow retention property, the initial expansion coefficient, and the compressive strength of 28 days old were measured. The results are shown in Table 2.

<Material used> Gas foaming substance B: commercial product, potassium persulfate Gas foaming substance C: commercial product, sodium perborate Carbonized substance b: Coal coke Carbonized substance c: commercial product, carbon black

<Measurement method> Initial expansion coefficient: Japan Society of Civil Engineers, “Design and Construction Guidelines for Expanded Concrete”, Appendix 2. The initial expansion coefficient measured according to the appendix "Method of measuring expansion coefficient of filled mortar using expansion material" showing "Construction procedure of filled mortar using expansion material". + Is the expansion side,
-Indicates the contraction side.

[0028]

[Table 2]

From Table 2, it can be seen that according to the present invention, a self-filling mortar composition having excellent fluidity retention, low heat of hydration, high initial expansion coefficient and low shrinkage can be obtained.

Experimental Example 3 100 parts of limestone cement consisting of 30 parts of cement material and 70 parts of fine limestone powder was used for gas foaming material A0.0.
1 part, 5 parts of carbonized material a and 5 parts of expansive material, and the amount and kind of silica fine powder and thickening agent shown in Table 3 were used, and 100 parts of fine aggregate were mixed with 100 parts of limestone cement. To obtain a mortar composition. Water / cement composition ratio 30%
Then, the mortar prepared with the amount of the fluidizing agent so that the bleeding water was not generated as much as possible was tested in the same manner as in Experimental Example 1 except that the flow retention, the material separation resistance and the compression strength were measured. The results are shown in Table 3.

<Materials used> Silica fine powder B: Silica fume, Blaine specific surface area 200,000 cm ² / g Thickener (I): Commercial product, polyethylene oxide

<Measurement method> Material separation resistance: 13.5% of mortar immediately after kneading
Observe the state of the mortar surface when packed in a mold of × 16 × 4 cm and hit the side of the mold 10 times with a mallet. If the surface is the same as before hitting, ○, if the amount of water increases due to hitting, △

[0033]

[Table 3]

From Table 3, it can be seen that according to the present invention, a self-filling mortar composition having excellent fluidity-holding property and less material separation can be obtained.

Experimental Example 4 For 100 parts of limestone cement consisting of 30 parts of cement material and 70 parts of limestone fine powder having a Blaine specific surface area shown in Table 4, 0.01 parts of gas foaming material A and 5 parts of carbonized material a,
5 parts of expansive material, 10 parts of fine siliceous powder and thickener (A)
The test was performed in the same manner as in Experimental Example 3 except that 0.1 part was used. The results are shown in Table 4.

[0036]

[Table 4]

From Table 4, it can be seen that according to the present invention, a self-filling mortar composition having excellent fluidity-retaining property, low heat of hydration and good resistance to material separation can be obtained.

Experimental Example 5 30 parts cement material and a Blaine value of 6000 cm ² /
Limestone cement 100 consisting of 70 parts of limestone fine powder of g
With respect to parts, 0.01 parts of gas foaming material A, carbonized material a5
Part, 5 parts of expansive material, 10 parts of fine silica powder and 0.1 part of thickener (A), and 100 parts of limestone cement.
Experimental Example 4 except that the amount of fine aggregate shown in Table 5 was mixed with each part to form a mortar composition and the adiabatic temperature rise value was measured.
Tested as above. The results are shown in Table 5.

[0039]

[Table 5]

From Table 5, it can be seen that the present invention provides a self-filling mortar composition having excellent flow retention and material separation resistance.

[0041]

The self-filling mortar composition of the present invention comprises:
It has excellent flow retention performance, material separation resistance, and good dimensional stability, and further has the effect of reducing the heat of hydration.

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) C04B 7: 345 C04B 24:38 A 24:38 22:02 22:02 22:06 A 22:06 22:04 22: 04 24:26 E 24:26 22:14 D 22:14) 111: 70 111: 70 (72) Inventor Kazuma Igarashi 2209 Aomi, Aomi-cho, Aomi-cho, Nishikubiki-gun, Niigata Electric Chemical Industry Co., Ltd. Aomi Plant (72) Inventor Naotaka Kondo 2209 Aomi, Aomi-cho, Aomi-cho, Nishikubiki-gun, Niigata Electric Chemical Industry Co., Ltd. Aomi Factory F-term (reference) 4G012 PA04 PA28 PB02 PC09

Claims (6)

[Claims] 1. A cement material containing 50 to 90% of limestone fine powder having a Blaine specific surface area of 3500 cm ² / g or more and limestone cement made of limestone fine powder, and fine aggregate are mixed, and a gas foaming substance and / or carbonization is further added. A self-filling mortar composition comprising a substance and a superplasticizer. 2. The self-filling mortar composition according to claim 1, wherein the cement material has a 3CaO.SiO ₂ content of 60% or more. 3. The self-filling mortar composition according to claim 1, which contains an expansive material. 4. The method according to any one of claims 1 to 3, which contains fine silica powder.
The self-filling mortar composition according to any one of 1. 5. The self-filling mortar composition according to claim 1, which contains a thickener. 6. A compressive strength of 28 days old is 35 N / mm ²
The self-filling mortar composition according to any one of claims 1 to 5, wherein: