JPS59169957A - Cement accelerator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cement quick-setting agent that rapidly sets cement mortar, concrete materials, etc. In the construction of tunnel lining, slope protection, etc., cement to which the above-mentioned cement quick-setting agent has conventionally been added is used. Mortar, concrete, etc. are usually used.

In particular, when spraying cement mortar, concrete, etc. on ceilings and walls such as in tunnels, spraying is done quickly to develop high strength in a short period of time after spraying to prevent flaking due to the material's own weight. A binding agent is required, and conventionally known quick-setting agents for this purpose are mainly based on sodium aluminate 7 carbonate, etc., but with conventional quick-setting agents, the amount used has been slightly increased or decreased. Spraying alone greatly changes the rapid setting of the material, so great care is required during construction.
Oda blowing materials do not have sufficient strength after setting, and have the disadvantage that it is difficult to hold the material on the object when spraying it to areas such as water leaks.

Yet again. Toremono's quick-setting agent exhibits strong alkalinity, and when spraying or mixing it in narrow tunnels, it can become powder and fly up into the air, posing a threat to the health of the constructor.

The present inventors conducted various efforts to find a cement quick-setting agent that does not have such drawbacks, and as a result, they arrived at the present invention shown below.

That is, two aspects of the present invention include (a) an alkali metal carbonate or/and sulfate; and (b) a soluble aluminum salt.

It is a cement quick-setting agent consisting of magnesium carbonate.

Examples of the alkali metal carbonate used as component (a) in the present invention include sodium carbonate and potassium carbonate, and sodium carbonate is particularly preferably used because it is inexpensive and highly effective.

Examples of alkali metal sulfates include sodium sulfate and potassium sulfate, but sodium salts are preferred since they have a greater effect on increasing the long-term strength of the material when sprayed.

In the present invention, the soluble aluminum salt used as component (b) includes acid aluminum, polyaluminum chloride, sodium sulfate, aluminum/potassium sulfate, etc., and aluminum sulfate is particularly preferred from the viewpoint of effectiveness.

The carbonate of magnesium is magnesium carbonate or cyclic magnesium carbonate, and basic magnesium carbonate is particularly preferably used.

In the present invention, the mixing ratio of component (a) and component (←) can be varied over a wide range.

←) If the amount of ingredients used is large, spraying will make the material soft and reduce its initial strength after setting.

Spraying may cause the material to fail to hold onto the object.

On the other hand, if the amount of component (a) used is small, the long-term strength of the material will decrease after construction.

On the other hand, if the amount of component (b) used is small, the rapid setting of the material will be impaired and the material will not be able to be held on the object by spraying.

On the other hand, if a large amount of component (B) is used in the lid, spraying after construction will reduce the long-term strength of the material, causing peeling of the lining surface and water seepage.

For this reason, in the present invention, the mixing ratio of component (a) and component (b) is usually Ca) / (b) =
It is preferably 0.1 to 9 (weight ratio) and 2% to 0.2-1.

The amount of the cement quick-setting agent of the present invention to be used varies depending on the type of concrete material, composition, etc. of the cement mortar, but it has a wide range of general applicability, and the amount of the cement mortar is approximately 1. :1 to 20% by weight), preferably 1 to 10% by weight.

If the amount of quick-setting agent used is too large, the long-term strength of the material will decrease when sprayed after construction, and on the other hand, if the amount used is too small, the quick-setting property of the material will be lost when sprayed.

Therefore, if too much or too little adhesive is used, the adhesive will peel off after spraying, and the coverage and durability of the object will be lost.

The method of applying the quick-setting agent of the present invention to sprayed materials such as cement mortar or cement concrete is the same as conventional methods, and in the case of the general dry spraying method, the quick-setting agent is applied to the cement, aggregate, etc. of the material. Add and mix, and then add an appropriate amount of water during construction.

On the other hand, in the case of semi-dry spraying, the quick-setting agent is dissolved in all or part of the water used, and sometimes the spraying agent is used at the nozzle at the tip of the gun to remove cement, aggregate, and as necessary. Spraying with water added to it is carried out by mixing it with the water.

When spraying the quick-setting agent of the present invention onto cement mortar, concrete, etc., there are many effects that can be obtained by adding it to the material. Added spraying does not pose a threat to the health of workers even when material dust is generated.

Second, the sprayed material to which the quick-setting agent of the present invention has been added has high rising strength after construction, and the sprayed material does not sometimes peel off.

In addition, long-term protection is high, and the protective wall on the lining surface can be stably maintained for a long period of time.

Other two products: Fumei's cement quick-setting agents can be applied not only to spray construction, but also to general cement construction, and are also highly effective in the production of various secondary concrete products.

Next, the present invention will be explained using examples.

Example 1 The cement quick setting agent of the present invention and ordinary Portland cement were mixed in a mortar mixer, and the resulting mixture was mixed with Content 2.
Pour into a 00 mil beaker.

Add water and knead by hand with a spatula.

The resulting cement mortar was then immediately 40 (width)
It was filled into a double mold of 40 (depth) x 160 (length) [units] and allowed to solidify.

Table 1 shows the results of needle penetration tests and compression tests performed on the condensates over time according to conventional methods.

For comparison, a test similar to the above was conducted using a conventional cement quick setting agent, and the results are also listed in Table 1.

Example 2 The cement quick setting agent of the present invention, ordinary Portland cement and sand were mixed in a mortar mixer for 5 minutes, then water was added and kneaded for 30 seconds, followed by 40 (In) x
It was filled into a double mold of 40 (depth) x 160 (length) [unit: man] and allowed to solidify.

The results of compression tests on the condensate over time are shown in the second section.
Shown in the table. As in the case of Example 1, a conventional cement quick setting agent was used for comparison, and the results of a test similar to the above are also listed in Table 2.

The aggregates produced by the cement quick setting agent of the present invention are shown in Table 1, Experiment Nos. 1 and 2. and 5, the penetration depth of the needle is small,
After 10 minutes, the level was below 1o. Control experiment numbers 9 to 16
It shows that the rapid setting property is better compared to the above.

In addition, in Experiment No. 3.4.6.7 and 8, the penetration depth after 10 to 20 minutes was the same as the control, but after 30 to 60 minutes there was a difference, indicating the advantage of the quick setting agent of the present invention. It is shown.

The compressive strength of the condensate in Table 1 is different from the composition in the 5-piece construction. Although fine aggregate was not added.

The strength in the case of the present invention is equivalent to or higher than that in the control case.

The strength in Table 2 is the value when standard sand is used as the fine aggregate.1 As shown in Table 2, in any case, as the cement/sand ratio is changed, the strength tends to increase. .

When compared with a control product at the same cement/sand ratio, it shows the same or higher value. As shown in Ibara 1.2, 9. The quick-setting agent of the present invention is used by adding it to the cement in the spraying material. When compared to conventional products, it shows excellent quick-setting properties and sufficient compressive strength.

It can be seen that it is superior to commercially available products.

Patent Applicant Nitto Kagaku EZ Co., Ltd. S. 1987 1986 Y/M Director General of the Patent Office Kazuo Wakasugi 1, Multiple Indication 1981 Patent Application No. 40g/'7 2, Invention Name: Cement quick-setting agent 3, Relationship with the case of the person making the amendment Patent applicant: 5-1-4, Marunouchi-chome, Chiyoda-ku, Tokyo 100, Column 5 of the detailed description of the invention in the specification to be amended, Contents (1) "Sodium 1-sulfuric acid hydrate" described on page 3, line 12 of the specification is corrected to "sodium aluminum sulfate."

(2) "Katsu" written in page 4 of Book I, line 8 of the coffin is amended to "katsu".

that's all

Claims (1)

[Claims] (a) Carbonate or/and sulfate of alkali metal ←
) A cement quick setting agent consisting of soluble aluminum salts and still magnesium carbonates.