JPS5838376B2 - Inorganic binder - Google Patents

Description

Detailed Description of the Invention The present invention provides a hydraulic inorganic binder, more specifically, granulated blast furnace slag containing an alkali metal hydroxide or an alkali metal hydroxide, an alkali metal carbonate or hydrogen carbonate, and an organic acid salt. Or it relates to an inorganic binder made by adding sugars.

Traditionally, steel slag and fly ash such as blast furnace slag and converter slag have been used as aggregate resources and as admixtures for cement and concrete, but they have not been actively used from the standpoint of resource and energy conservation. The properties of cement are used to improve the shortcomings of cement.

However, in the recent era of limited supply and high prices of heavy oil, the situation has become such that high value-added use of these resources is required.

Blast furnace slag and converter slag both have a high CaO content and are quite reactive, but granulated blast furnace slag in particular is known to have latent hydraulic properties, and it is used in blast furnace cement and high Examples include sulfate slag cement.

However, these granulated blast furnace slag cements have low initial strength, poor surface hardness and abrasion resistance of the cured product, and are susceptible to weathering and disintegration, so their uses are considerably limited.

The purpose of the present invention is to improve these drawbacks by adding a small amount of alkali metal hydroxide, or alkali metal carbonate or hydrogen carbonate together with the same to finely powdered granulated blast furnace slag. This makes it possible to develop an initial strength higher than that of ordinary Boltland cement, and by adding organic acid salts or sugars to it, it improves workability, particularly increases fluidity, and imparts properties such as increased mechanical strength. The purpose of this invention is to provide a hydraulic inorganic binder that has the following properties.

That is, the present invention has a Blaine specific surface area of 3,000
1 to 30 parts by weight of an alkali metal hydroxide, or 1 to 30 parts by weight of an alkali metal carbonate or hydrogen carbonate together with 1 to 30 parts by weight of an alkali metal hydroxide, per ioo parts by weight of granulated blast furnace slag of 1 to 30 parts by weight of granulated blast furnace slag of 1 to 30 parts by weight. parts by weight, further O,
It is characterized by adding 01 to 5.0 parts by weight of an organic acid salt or saccharide.

The present invention will be explained in detail below.

An example of the chemical composition of granulated blast furnace slag is S i02.
3 2~36φ, Al20312~20, Ca035
~43%, Mg00.5~10%, TiO20.
Sections 1 to 3.

In addition, in the present invention, the fineness of the granulated blast furnace slag is important, and the Blaine specific surface area is 3,000 cr.
/g or more is required.

As the fineness increases, the strength development also increases, but the compressive strength of the initial material ◆ is due to the Blaine specific surface area of 3,00
0 cr? It increases significantly when it exceeds t/g.

Considering strength development and economic efficiency, the preferable Blaine specific surface area is 5,000 to 8,000crit.
/ g.

Furthermore, it is important to include an alkali metal hydroxide in order to enhance the hydration activity of the granulated blast furnace slab, and the proportion thereof is 1 to 30 parts by weight per 100 parts by weight of the granulated blast furnace slab.

If the amount is less than 1 part by weight, the effect of developing strength will be small, and if it is present in excess of 30 parts by weight, the strength will not increase so much and this is not practical.

The preferred proportion of alkali metal hydroxide is 2 to 15 parts by weight.

Specific examples of alkali metal hydroxides include sodium hydroxide, potassium hydroxide, and lithium hydroxide, and although there is little difference in their strength-enhancing effects, they are not used industrially. Sodium hydroxide is most preferred economically.

A similar effect can be obtained when an alkali metal hydroxide is used in combination with an alkali metal carbonate or hydrogen carbonate such as sodium potassium or lithium.

However, there were problems with mortar flow down, large concrete slump loss, and poor fluidity, but by adding organic acid salts or sugars, it not only significantly improved, but also improved compressive strength. can be increased.

The amount added is 0.01 to 100 parts by weight of cement.
The amount is 5.0 parts by weight, preferably 0.1 to 0.5 parts by weight.

o. If the amount is less than oi parts by weight, sufficient fluidity of paste, mortar, and concrete cannot be obtained and the strength-enhancing effect is small.

If it exceeds 0.5 parts by weight, the setting time will be significantly increased and there will be no advantage.

To produce the inorganic binder of the present invention, it is only necessary to mix granulated blast furnace slag, an alkali metal hydroxide, an alkali metal carbonate or bicarbonate, and an organic acid salt or saccharide.

The inorganic binder of the present invention can be used in the same applications as ordinary boltland cement.

Additionally, it is commonly used as an additive in Bortland cement.

For example, it may be used in combination with a hardening accelerator, AE agent, foaming agent, cement water reducing agent, etc. without any problem.

As explained above, by adding a specific amount of alkali metal hydroxide [arsenic acid or alkali metal hydroxide and alkali metal carbonate or hydrogen carbonate] to granulated blast furnace slag, initial strength greater than that of ordinary Bortland cement can be developed. However, it had drawbacks such as fast setting time and large flow down.

This problem was solved by adding organic acid salts or sugars, resulting in a breakthrough in practical use.

Conventional cement water reducers cannot achieve this effect.

Here, organic acid salts include gluconic acid, tartaric acid, stearic acid, formic acid, and acetic acid. Oxalic acid, malonic acid. It refers to sodium and potassium salts such as succinic acid, maleic acid, fumaric acid, and malic acid, and sugars refer to glucose, fructose, sucrose, maltose, and lactose.

Examples will be described in detail below.

Example 1 Granulated blast furnace slag (Blaine specific surface area 5 6 7 0 va
l/g), 7.5 parts by weight of sodium hydroxide, sodium gluconate or sucrose added, and 200 parts by weight of surface dry sand as aggregate, mixed with 40 parts by weight of water.
A cement mortar was obtained by adding parts by weight and kneading, and the change in flow value over time was measured.

Flow value measurement was performed according to the method specified in JIS R 5201.

Similar tests were conducted by changing the fineness of the granulated blast furnace slag and the amount of sodium hydroxide added, and similar trends were found.

Furthermore, when soda carbonate and sodium bicarbonate were used in combination, the flow value increased slightly.

Example 2 Compressive strength was measured in the same formulation as in Example 1.

Similar measurements were performed by changing the fineness of the granulated blast furnace slag and the amount of sodium hydroxide added, and similar trends were found.

In addition, when soda carbonate or soda hydrogen carbonate was used in combination, a slight increase in the 28-day strength was observed.

Claims (1)

[Claims] 1. 1 to 30 parts by weight of an alkali metal hydroxide or 1 to 30 parts by weight of an alkali metal hydroxide and an alkali to 100 parts by weight of finely powdered granulated blast furnace slag with a Blaine specific surface area of 3,000 cvt/g or more. An inorganic binder containing 1 to 30 parts by weight of a metal carbonate or alkali metal hydrogencarbonate and 0.01 to 5 parts by weight of an organic acid salt or saccharide.