JP3114478B2 - Grout wood - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grout material, and in particular, has less bleeding, a longer fluidity retention time,
Moreover, the present invention relates to a grout material excellent in strength development.

[0002]

2. Description of the Related Art Grouting materials used for filling gaps in structures, ground, etc., are required not only to have less bleeding and to have excellent strength, but also to ensure sufficient working time during filling. Therefore, it is required that the fluidity retention time be long.

Conventionally, as a grout material, ordinary cement or early-strength cement has been generally used.

[0004]

A grout material using ordinary cement has many drawbacks and a long retention time of fluidity, but has a drawback of poor strength development.

On the other hand, even a grout material using an early-strength cement has a lot of bleeding and good strength development, but has a drawback that a fluid retention time is short.

[0006] It is conceivable to mix ordinary cement and early-strength cement. However, simple blending of ordinary cement and early-strength cement causes a large amount of bleeding.
The fluidity retention time is short, and the required properties as a grout material cannot be sufficiently satisfied.

An object of the present invention is to solve the above-mentioned conventional problems, and to provide a grout material having less bleeding, a longer fluidity retention time, and excellent strength development.

[0008]

The grout material of the present invention comprises:
A pulverized mixture obtained by mixing and pulverizing clinker for early-strength cement, clinker for ordinary cement, and gypsum dihydrate, wherein the mixing ratio of clinker for early-strength cement to clinker for ordinary cement is 1: 1 to 3 by weight. : 1 and the mixing ratio of gypsum to the total of the clinker for high-strength cement and the clinker for ordinary cement is _{3 to 3 in} terms of SO 3.
7% by weight and a Blaine value of 4000 to 600
It is characterized by containing a pulverized mixture of 0 cm ² / g and inorganic fine powder.

Hereinafter, the present invention will be described in detail.

The grout material of the present invention comprises clinker for early-strength cement (hereinafter sometimes referred to as "HP clinker"), clinker for ordinary cement (hereinafter sometimes referred to as "NP clinker") and gypsum. And an inorganic fine powder.

In the present invention, the mixing ratio of the HP clinker and the NP clinker is expressed by weight ratio of HP clinker: N
P clinker = 1: 1 to 3: 1. If the amount of the HP clinker is less than 1 time by weight of the NP clinker, sufficient strength expression cannot be obtained, and if the amount exceeds 3 times by weight, the fluidity decreases.

The mixing ratio of gypsum to the total of HP clinker and NP clinker is _{3 to 3 in} terms of SO 3.
7% by weight. If this ratio is less than 3% by weight, the bleeding characteristics are poor, and if it exceeds 7% by weight, the fluidity retention time is reduced.

The pulverized mixture according to the present invention is prepared by introducing HP clinker, NP clinker and dihydrate gypsum into a mixing and pulverizing machine such as a mill at the above-mentioned predetermined ratio, and having a Blaine value of 4000 to 60.
It is finely ground to 00 cm ² / g. The Blaine value is often bleeding is less than ^{4000cm 2 / g, 6000cm 2 /} g greater than the holding time hydration progresses rapidly liquidity is shortened.

In this grinding, the mill outlet temperature is 8
The temperature is preferably set to 5 ° C. or lower. That is, when the mill outlet temperature exceeds 85 ° C., the gypsum dihydrate is dehydrated to form hemihydrate gypsum. The hemihydrate gypsum has a mill outlet temperature of 85 ° C. or lower in order to shorten the retention time of the fluidity of the grout material and to prevent the formation of hemihydrate gypsum by dehydration of gypsum. In order to reach such a mill outlet temperature, it may be necessary to sprinkle water inside the mill.

The grout material of the present invention contains the pulverized mixture thus obtained and the inorganic fine powder. The preferred content is 10 to 50 parts by weight of the inorganic fine powder to 100 parts by weight of the pulverized mixture. It is. Crushed mixture 1
If the amount of the inorganic fine powder is less than 10 parts by weight with respect to 00 parts by weight, the amount of bleeding increases, and if it exceeds 50 parts by weight, the strength is deteriorated.

As the inorganic fine powder, use is made of one or more of calcium carbonate, blast furnace slag, silica fume, etc., having a Blaine value of 6000 cm ² / g or more, preferably 6000 to 10000 cm ² / g. These may be added and mixed at the time of pulverization and mixing of the pulverized mixture, and may be used by simultaneous pulverization and mixing, or may be added to and mixed with the pulverized mixture obtained by pulverization and mixing.

The grout material of the present invention can be used in the same manner as a normal grout material, and has a water / cement ratio of 50-7.
After mixing at about 0%, it may be filled into a repair part or the like. In addition, if necessary, a water reducing agent, a foaming agent, a foaming agent and the like can be added and mixed.

Such a grout material of the present invention is a high-performance grout material that can sufficiently satisfy the required performance values as a backing material for PC paving.

Required performance value of quick-setting backfill material for PC plate pavement Flowability by JA funnel Immediately after kneading: 15 seconds or less After 30 minutes of kneading: 17 seconds or less 12 hours strength: 20 kg / cm ² or more (16 hours strength: (30 kg / cm ² or more) Bleeding rate: 2% or less The fluidity by a JA funnel is defined as the PC grout test method (JSCE) of the Japan Society of Civil Engineers “Concrete Standard Specifications”.
-1986), and the strength is specified by the PC grout compressive strength test method, and the bleeding rate is specified by the bleeding rate test method.

[0020]

In general, HP cement has excellent initial strength. However, when manufactured in a factory, the temperature in the mill at the time of pulverization is likely to be high, and the gypsum changes to hemihydrate or soluble anhydrous gypsum by dehydration of crystallization water. As a result, the retention time of the flowability of the grout is extremely short, and the workability of pouring is poor.
In contrast, NP cement is not as good as HP cement, but often has a short fluidity retention time for the reasons described above. Further, since the grout has a low fineness, the bleeding is large, and the strength does not satisfy the required standard value of 12 hours.

Further, it is necessary to reduce the bleeding of the grout for backfilling the PC plate as much as possible. In order to satisfy the two conditions of maintaining the pourable fluidity retention time and bleeding, it was not possible to use simple cement or plain cement or to simply mix them.

First, to reduce the required bleeding value, it is most effective to increase the fineness of the cement. However, in the case of HP cement, if the degree of fineness is increased, the hydration reaction at the very beginning occurs rapidly, and it becomes difficult to maintain fluidity. Therefore, it is a feature of the present invention that an appropriate amount of NP clinker and HP clinker, which have a lower hydration reactivity than HP, are pulverized and pulverized at the same time so that each feature can be effectively acted on. Here, the added gypsum contributes to bleeding and reduction of shrinkage of the cured product.

In the present invention, HP clinker, NP
Clinker and gypsum are simultaneously pulverized, and the mill outlet temperature is set to 85 ° C. or lower in the pulverization process, and if necessary, water is sprinkled in the mill to pulverize without causing dehydration of the gypsum. As a result, since each component is uniformly mixed at the particle level, the advantages of each component are synergistically expressed, bleeding is reduced, fluidity retention time is long, and strength development is excellent. It will be.

However, bleeding can be further reduced by adding and mixing the inorganic fine powder to such a crushed mixture, and even if the crushed mixture has a relatively low Blaine value, good crush resistance can be obtained. Bleeding characteristics can be obtained.

[0025]

The present invention will be described more specifically below with reference to examples and comparative examples.

Examples 1 to 3 2: 1 (weight ratio) of HP clinker and NP clinker
Gypsum is 5.0% by weight in terms of SO _{3 based on} the sum of the HP clinker and the NP clinker.
And milled and mixed with a mill to obtain a Blaine value of 4400c.
A grout material of m ² / g was obtained. The chemical composition of this grout material is as shown in Table 1.

[0027]

[Table 1]

With respect to 100 parts by weight of the grout material, inorganic fine powder shown in Table 2 was added and mixed at a ratio shown in Table 2, and a water / cement ratio shown in Table 2 (W / C: wt%) Then, 0.8% by weight of a water reducing agent ("Mighty 150" manufactured by Kao Corporation) was added to the cement and kneaded, and each was subjected to a test prescribed for a quick-setting backing material for pavement on a PC plate. The results are shown in Table 2.

Comparative Example 1 A test was conducted in the same manner as in Example 1 except that no inorganic fine powder was added, and the results are shown in Table 2.

[0030]

[Table 2]

From Table 2, it can be seen that the grout material of the present invention obtained by adding inorganic fine powder to a crushed mixture obtained by crushing HP clinker, NP clinker and gypsum in a mixed state has a fluidity retention time and bleeding. It is evident that excellent properties are exhibited in all aspects of strength.

[0032]

As described in detail above, according to the grout material of the present invention, a grout material having little bleeding, a long fluidity retention time and excellent strength development is provided.

Continuation of the front page (72) Inventor Fuichi Takiguchi 1-297 Kitabukuro-cho, Omiya-shi, Saitama Mitsui Materials Co., Ltd. Cement Research Institute (56) References JP-A-7-206485 (JP, A) JP-A-4 -104929 (JP, A) JP-A-63-210048 (JP, A) JP-B-61-26598 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) C09K 17/10 C09K 17/06 C09K 17/44 C04B 7/04

Claims (1)

(57) [Claims] 1. A pulverized mixture obtained by mixing and pulverizing clinker for early-strength cement, clinker for ordinary cement and gypsum dihydrate, wherein the mixing ratio of the clinker for early-strength cement and the clinker for ordinary cement is in weight ratio. 1: 1 to 1
3: 1, the mixing ratio of gypsum to the total of the clinker for high-strength cement and the clinker for ordinary cement is ₃ to 7% by weight in terms of SO ₃ , and the Blaine value is 4000 to 6000 cm ² / g. A grout material characterized by containing a crushed mixture as described above and an inorganic fine powder.