JPH0455352A - Water stop material - Google Patents

Abstract

PURPOSE:To shorten setting time, to early produce strength and to enhance water sealing effect by incorporating a CaO-Na2O-Al2O3 type fired or melted product and cement. CONSTITUTION:Ca, Na and Al sources are mixed so that the amts. are regulated to 25-53 wt.%, 5-20 wt.% and 35-70 wt.% (expressed in terms of CaO, Na2O and Al2O3), respectively, the mixture is fired or melted at >=1,300 deg.C for >=15 min and pulverized to obtain a CaO-Na2O-Al2O3 type fired or melted product having >=3,000 cm<2>/g Blaine value and 20-90 wt.% of this fired or melted product is blended with 80-10 wt.% cement.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides cement with Cao-Naio-A 120
This invention relates to a stopper wood to which 20 to 90% by weight of 3-based fired or melted material (hereinafter abbreviated as CNA clinker) is added.

[Prior Art] When carrying out underground construction work such as tunnel construction, leakage of underground water and its treatment become major issues.

Conventionally, methods have been known in which a mixture of cement and water glass or a mixture of cement and amorphous calcium aluminate is adhered to and injected into a water leak. Also,
The present inventors have developed a CaON ago-A Igo 3-based setting and hardening accelerator for cement (Japanese Patent Application No. 63-32772).
0) was also proposed.

[Problems to be Solved by the Invention] A mixture of cement with water glass added or a mixture of cement and amorphous calcium aluminate requires several minutes to set, so a sufficient water-stopping effect cannot be obtained.

Mortar made by adding Cao-Na20 A 1203 type setting hardening accelerator for cement to ordinary Portland cement at a concentration of 10% takes about 5 minutes to set, so a sufficient water-stopping effect cannot be obtained. .

[Means for Solving the Problems] Therefore, the present inventors have researched a material that solves the drawbacks of the prior art, that is, has a setting time of less than 1 minute and has quick strength development, and has developed the present invention. Completed the invention.

That is, the gist of the present invention is that Cao, Na as O
And in terms of Al2o3, CaO is 25-53% by weight, Na2O is 5-20% by weight and Al2O3 is 35% by weight.
The water stop material is made by adding 20 to 90% by weight of CNA clinker, which is 70% by weight, to cement.

The raw material for CNA clinker contains CaCOs as a Ca source.
, Cao, Ca(OH)t, etc. as a Na source.
ax CO3 etc., Al1103 as Al source,
AI(OH)3 etc. can be used. In addition, Na and AI
Sodium aluminate can also be used as a common source.

The mixing ratio of each raw material is such that when fired or melted, Ca
b, CaO is 25 in terms of Na2O and Al2O3
~53 wt%, 5-20 wt% NagO and Alx
The composition should be 35-70% by weight of O3. In this case, the NagO content evaporates during firing or melting, so
It is necessary to mix in large quantities. Note that the raw materials are mixed by conventional means.

If CaO is less than 25% by weight, the hydration reactivity of the CNA clinker is low and no water stopping effect is observed. On the other hand, CaO is 53
Exceeding the weight percentage is not preferable because free 11cao is generated, which becomes Ca(OHh) and causes partial expansion when kneaded with water.

Since Na20 is less than 5% by weight and the setting time is about several minutes, a sufficient water-stopping effect cannot be obtained. On the other hand, Na2
If O exceeds 20% by weight, not only the initial strength is low, but also Na2O volatilizes a lot during firing or melting, causing severe damage to the furnace, making it impractical.

When Al2O3 is less than 35% by weight, the same phenomenon as when CaO exceeds 53% by weight occurs, which is not preferable.

On the other hand, when Al2O3 exceeds 70% by weight, the hydration reactivity of the CNA clinker is low and no water stopping effect is observed.

CNA clinker is produced by mixing a Ca source, a Na source, and an Al source by a conventional means, and then heating the mixed sample in a heating furnace such as an electric furnace or a rotary kiln to 1300°C or higher, preferably 150°C.
Fired or melted at 0 to 1800°C for 15 minutes or more, and after cooling, the resulting fired or melted product was 3000 cm in Blaine value.
2/g or more, preferably 4,000 to 6,000 cm” 7
Use one that has been ground to 100 g. The CNA clinker contains 3
Contains crystals and glass of Cao-2N a20 .5A 1203.

The amount of CNA clinker added to cement is 20%
-90% by weight, preferably 30-80% by weight. 2
If it is less than 0% by weight, the setting time becomes slow and there is no water stopping effect. On the other hand, if it exceeds 90% by weight, it is not preferable because the setting time becomes slow.

As for cement, ordinary early-strength Portland cement,
Fly ash cement etc. can be used.

Water can be stopped by attaching a water-stopping material made of the above mixed powder to the leaking area and its surrounding area, or by injecting it as a slurry.

[Execution/Examples] Examples 1 to 7, Comparative Examples 1 to 4 CaCO3 manufactured by Hakushin Kagaku Kenkyusho ■ as a Ca source, Nazc Oa manufactured by Toyo Soda ■ as a Na source, and Nazc Oa manufactured by Showa Denko ■ as an Al source. AlxO3 was blended to have the composition shown in Table 1, mixed and pulverized in a ball mill, and the resulting mixed sample was melted in an industrial electric furnace at 1700° C. for 15 minutes, then taken out from the furnace and cooled. The obtained melt was ground in a ball mill to a Blaine value of 5000 cm2/g to obtain CNAN cotton powder having the composition shown in Table 1.

Table 1 (% by weight) Using the 7 linkers shown in Table 1 and ordinary Portland cement manufactured by Nippon Cement@, they were mixed in a type mixer as shown in Table 2 to make anchoring pieces.

Table 2 Using the water stop material shown in Table 2, a mixture of water/water stop material = 0.7 was quickly kneaded by hand for 10 seconds. The setting time and compressive strength of this kneaded product 1 hour after kneading were measured, and the results are shown in Table 3. The setting time and compressive strength of the kneaded product were measured using a tester specified in JISR5201.

As shown in Table 3, it was found that with the fastener of the present invention, the starting time could be reduced to within 1 minute, and the compressive strength after 1 hour could be increased.

[Effects of the Invention] The present invention is a water-stopping material made by adding 20 to 90% by weight of CNA clinker in a specific range to the inside of cement, and by using this material, the water-stopping effect can be enhanced.

Patent applicant: Nippon Cement Co., Ltd.

Claims (1)

[Claims] (1) In terms of CaO, Na_2O and Al_2O_3, CaO is 25-53% by weight, Na_2O is 5-2% by weight.
A water-stopping material made by adding 20 to 90% by weight of a fired product or a molten product containing 0% by weight and 35 to 70% by weight of Al_2O_3 to cement.