JPS59108073A - Liquid accelerator for setting of cement - Google Patents

Abstract

PURPOSE:A liquid accelerator for setting of cement preventing crystallization and precipitation of aluminum hydroxide without damaging accelerating properties, containing an aqueous solution of gluconic acid (gluconate), alkali aluminate, and alkali carbonate. CONSTITUTION:(A) An alkali aluminate (e.g., potassium aluminate, etc.) and (B) an alkali carbonate (e.g., potassium carbonate, etc.) are dissolved in water, respectively, and adjusted to preferably 20-40wt% concentration. (C) preferably 0.1-1wt% gluconic acid (gluconate) based on the component A is added to one of the solutions, and both solutions are blended to give the desired accelerator.

Description

[Detailed description of the invention] The present invention relates to a liquid quick setting agent.

Conventionally, a powder mixture of an alkali aluminate salt (eg, sodium aluminate) and an alkali carbonate (eg, soda carbonate) has been used as a quick setting agent for cement. For example, when spraying cement mortar and confetti, a quick-setting agent is mixed into the mixture of cement and aggregate, and while it is supplied by a dry sprayer, it is combined with water pumped from a separate system near the nozzle tip. I'm spraying it. However, in spraying, the material is pumped in the form of powder until it joins with water, which can harm the working environment due to the generation of dust, cause uneven mixing of the quick-setting agent, and even cause moisture content in the aggregate. Strict management of materials, etc. was required since there is a risk of reacting with the material and clogging the thread path.

In order to solve the above-mentioned problems, it has been proposed to supply a liquid quick setting agent to the water flow path (Japanese Patent Application Laid-open No. 163672/1983).

However, in this method, even if a liquid quick-setting agent is supplied, aluminum hydroxide crystals are formed when aluminum/acid salt and alkali carbonate are mixed as a water bath liquid.
The process is complicated in that the aluminate and the alkali carbonate must be supplied as separate water bath liquids, since their functionality is low and there is a risk of clogging the yarn path. In addition, this method also takes sufficient measures against dust.

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As a result of various investigations to solve these drawbacks, the present inventor found that gluco/acid or its salt is effective in preventing the crystal precipitation of aluminum hydroxide without impairing the rapid setting performance. This discovery led to the completion of the present invention.

That is, the present invention is a liquid quick-setting agent made by blending aluminum/acid alkali salt, alkali carbonate, and gluconic acid or its salt in water.

To further explain the present invention, as the aluminum/acid alkali salt, aluminum/acid salts of sodium and potassium are generally used, but potassium salts are preferred from the viewpoint of solubility. As for alkali carbonates, sodium and potassium salts are also common, and potassium salts are preferred because of their solubility at low temperatures. The mixing ratio of these salts to water should be 10 to 60% by weight and preferably 20 to 40% by weight as the individual concentration of the alkali aluminate salt and steamed alkali carbonate to improve quick setting and workability during use. desirable from the point of view of improvement;
In addition, in such a ratio, σ', which sets the M ratio of alkali aluminate to alkali carbonate to 10:90 to 80:20, preferably 20:80 to 60:40, is suitable for rapid setting and economical efficiency. This is desirable from the standpoint of improving

Gluconic acid or its salt is a necessary component to prevent crystal precipitation of aluminum hydroxide when alkali aluminate salt and alkali carbonate are mixed in a water bath solution and to maintain rapid setting performance. be. By using this ingredient, there is also the advantage of suppressing dust generation. The amount of gluco/acid or its salt to be used is preferably 0.01 to 10 glucosol per weight, particularly 0.1 gluco/acid or its salt.
-11 amount is good. If the amount used is less than 0.01% by weight, it will not be effective in inhibiting crystal precipitation of aluminum hydroxide, and if the amount exceeds 10 M%, the rapid setting performance will decrease.

Examples of gluconic acid or its salt include gluco/acid and salts of sodium, potassium, calcium, and the like. In addition, when adding gluconic acid or its salt, KOH,
If an alkaline substance such as NaOH is used in combination, the rapid setting and solubility of aluminum hydroxide can be improved.

The product of the present invention can be used by dissolving it in spraying water in advance, or by pressurizing it into spraying water using a pump or the like. In continuous spraying work, the amount used is about 2 to 8% by weight, preferably 4 to 6% by weight, based on the cement.

The effects of using all the products of this invention are as follows.

(1) The liquid quick setting agent can be used as a single liquid.

(2) The generation of aluminum hydroxide dust can be reduced even after long-term storage.

(4) Rapid setting performance can be improved.

Examples will be described in more detail below.

Example A potassium aluminate solution was prepared by dissolving 1 part in 50 parts of potassium aluminate and 2 parts in 50 parts of water in hot water at 80°C. Separately, sodium gluconate was added to potassium aluminate in an amount of 0.005 to 20 to produce potassium aluminate ha. On the other hand, add 50 Ky of potassium carbonate to 55 Ky of water.
A potassium carbonate solution was made by mixing 0 and 9. The above potassium aluminate solution and potassium carbonate bath liquid were mixed at a volume ratio of 11 to obtain a liquid quick-setting agent.

In order to evaluate the quick-setting performance of this liquid quick-setting agent, 1000 g of ordinary Poldora/Docemet/T, 30009 sand, 50 g of liquid quick-setting agent, and 450 g of water were mixed for 30 seconds, then quickly packed into a mold and poured with water. A Broctor resistance test was performed every minute afterward. The results are shown in the table.

In addition, when each liquid quick-setting agent was left in a room at 5° C. for 10 days and precipitation of aluminum hydroxide was confirmed, precipitation was observed when less than 0.005 weight percent of sodium gluconate was added.

Next, using the above blending ratio, 1 of each was applied by dry spraying method.
17+3 spraying work was carried out and the situation was measured.

As a result, 0.01 to 10% by weight of sodium gluconate
When the quick-setting agent with 7IO added was used, there was little rebound and the amount of dust was extremely small, ranging from 1 DO to 160 force/t/min. In contrast, without the addition of sodium dalconate, the force is 568 m/min, and the force of 0.005 g/m
It was 625 force und/min. It should be noted that the use of 20 weight grated bean paste was not practical due to delayed curing.

Patent applicant Denki Kagaku Kogyo Co., Ltd.

Claims (1)

[Claims] A liquid quick-setting agent made by blending water with an alkali aluminate salt, an alkali carbonate, and gluconic acid or its salt.