JPS593427B2 - Water reducing agent composition for hydraulic cement - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel water reducing agent composition for hydraulic cement having excellent performance.

In mortar or concrete construction, many admixtures for hydraulic cement are used depending on the purpose of use, such as air entraining agents, water reducing agents, setting retarders, setting accelerators, waterproofing agents, and swelling agents.

Water reducing agents are one of the most commonly used admixtures, and are expected to have the following effects.

That is, (1) it increases the workability of mortar and concrete that have not hardened yet;

Also, if the workability is the same, the amount of water used can be reduced.

(2) Since the amount of water used can be reduced, the strength after construction is increased.

Also, if the strength is the same, the amount of cement used can be reduced.

(3) Increase watertightness, etc.

Oxycarboxylic acids or their salts have good properties as water-reducing agents and have been widely used in recent years, but the present inventor conducted research with the aim of developing water-reducing agents with even better water-reducing effects. The present inventors have discovered that by adding carbonate and/or bicarbonate in a specific ratio to a water reducing agent, a mutually beneficial effect is exhibited and the effectiveness of the water reducing agent is dramatically improved, leading to the completion of the present invention. .

That is, the present invention comprises 95 to 50 parts by weight of ([) oxycarboxylic acid or/and its salt (hereinafter sometimes referred to as the first component) and (71 parts by weight of bicarbonate or/and bicarbonate (hereinafter referred to as the second component)).
The present invention provides a novel water-reducing agent composition for hydraulic cement, characterized in that it contains a mixture of 5 to 50 parts by weight (sometimes referred to as "component") as an active ingredient.

The first component oxycarboxylic acid used in the present invention includes gluconic acid, citric acid, 2-ketogluconic acid,
Tartaric acid and the like are used, and as the oxycarboxylic acid salts, alkali metal salts thereof such as ammonium salts, sodium salts and potassium salts are used, and among these, sodium gluconate is preferably used.

Further, as the carbonate and/or bicarbonate used as the second component, an alkali metal salt such as a sodium salt or a potassium salt, or an ammonium salt is used.

The mixing ratio (weight basis) of the first component and the second component is 95~
The ratio is 50:5 to 50, preferably 90 to 60:10 to 40, and the amount of the mixture added when mixing concrete, mortar, cement paste, etc. is 0% to cement.
．． 02 to 1.0 weight ratio, preferably 0.05 to 0.5 weight ratio.

The water reducing agent of the present invention is used as a dry powder or an aqueous solution,
Further, if necessary, it may be used in combination with other admixtures to obtain a desired hydraulic cement composition.

By adding the composition of the present invention, the dispersibility of hydraulic cement becomes extremely good, and the water-reducing effect and strength of hydraulic cement formulations such as mortar and concrete are significantly enhanced.

Next, the present invention will be explained by examples.

Parts and parts are based on weight unless otherwise specified.

Example 1 A mortar flow test was conducted to clarify the performance of a mixture of oxycarboxylate and carbonate or bicarbonate as a water reducing agent.

The results are shown in Table 1 and FIGS. 1 to 3.

Note that FIGS. 1 to 3 illustrate experiments AI to ■, respectively.

The composition is Onoda Ordinary Portland Cement) 500. ! i
i', To 500 g of Toyoura standard sand, add 170 g of water containing a mixture of the first and second components at 0.3% and 0.5% of the weight of cement, JfS-R5201 (1964)
Flow measurements were carried out using the flow test method.

From the results in Table 1 and FIGS. 1 to 3, the water-soluble salt mixture of the first component and the second component of the present invention has a ratio of 95 to 50:5 to 50.
It is clear that there is a significant additive effect between the mixing ratios of .

Example 2 Table 2 shows the results of a mortar test performed on the following additives.

The test method followed JIS-R5201 (1964).

The experiment was conducted using Onoda Ordinary Portland Cement as the cement and Toyoura Standard Sand as the sand so that the flow value remained constant at about 210 mm.

It can be seen from Table 2 that the water reducing agent composition of the present invention has excellent water reducing effects and strength enhancing effects.

Additive A Sodium nigerconate B: Sodium citrate For 80 parts of sodium C nigerconate 20 parts sodium carbonate D = 75 parts of nibblecon sodium 25 parts ammonium carbonate E: For 80 parts of sodium citrate 20 parts sodium carbonate

[Brief explanation of drawings]

1 and 3 are diagrams showing the flow test results of the water reducing agent in Example 1.

Claims (1)

[Claims] 1(1) Oxycarboxylic acid or/and salt thereof95-
50 parts by weight and (11) carbonate or/and bicarbonate 5
A water reducing agent composition for hydraulic cement, characterized in that it contains as an active ingredient a mixture consisting of ~50 parts by weight. 2. The water reducing agent composition according to claim 1, wherein the carbonate and/or bicarbonate are an alkali metal salt or an ammonium salt. 3(1) Oxycarboxylic acid or/and its salt 90~
60 parts by weight and (il) carbonate or/and bicarbonate 1
The water reducing agent composition according to claim 1, characterized in that it contains 0 to 40 weight parts of the mixture as an active ingredient.