JPH0147421B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to inorganic binders.

It has been widely known that materials with latent hydraulic properties, such as blast furnace slag, can be used as a binder by adding an alkaline stimulant, but there is no material that is physically and economically superior to ordinary Portland cement. Currently, products other than blast furnace cement are not widely used. The present invention not only compensates for the drawbacks of conventional slag-based cement, but also
The purpose is to obtain performance superior to that of ordinary Portland cement.

The present invention uses latent hydraulic materials, such as steel slag such as blast furnace slag and converter slag, and fly ash generated from thermal power plants, as a raw material for the binder, and at least a portion of these materials is crushed. After having a Blaine specific surface area of 2000 cm ² /g or more, 1 part (by weight, the same shall apply hereinafter) of the raw material as a curing regulator is added.
It is an inorganic binder characterized by adding ~30 parts of alkali metasilicate or a substance containing alkali metasilicate.

As the substance having latent hydraulic properties, the above-mentioned substances are used, and among them, rapidly cooled (ground water) slag, in particular, has a vitrification rate of 90% or more and a basicity (CaO + MgO + Al ₂ O ₃ /SiO ₂ ) of 1.7 or more. most preferred. Converter slag and fly ash can be used as is, but converter slag contains Al ₂ O 3 and SiO ₂ components, and fly ash contains two components: Al 2 O ₃ and SiO.
Since the CaO component is low, it is desirable to mix blast furnace slag, lime, activated silica, activated alumina, Portland cement, etc. with the CaO component to adjust the basicity as described above. The fineness of the raw material needs to be 2000 cm ² /g or more in Blaine specific surface area, and if it is less than this, the strength will not be sufficiently developed. There is no particular upper limit on the upper limit, but excessive grinding is not economical, and physical properties tend to result in large drying shrinkage and poor bending strength, resulting in a long-term decline. Therefore, 8000cm ² /
It is preferable to set it to about 100 g.

Hardening regulators include silicates, hydroxides, carbonates, hydrogen carbonates, sulfates, sulfites, nitrates, nitrites, chlorides, phosphates, and organic acid salts of alkali metals or alkaline earth metals. Possible examples include alkaline salts. However, in the present invention, it has been found that among these, those containing mainly alkali silicate, particularly alkali metasilicate, give preferable results. Alkali metasilicate includes lithium, sodium, and potassium salts, but sodium salts are preferred industrially.

It has also been found that when alkali metasilicate is used in combination with other alkaline salts, good results can be obtained in terms of strength development. Examples of the alkaline salt used in combination include vitreous sodium silicate No. 1, 2, 3, and 4, crystalline sodium pyrosilicate, and sodium orthosilicate, and the composition range is Na ₂ O/
Particularly preferred is SiO ₂ =0.1 to 5.0 (molar ratio). These may be used in the form of powder or solution, and the amount added is 6 to 18 parts as alkali metasilicate or a mixture of alkali metasilicate and other alkaline salts to 100 parts of the raw material. If the amount used is other than this, the strength development will not be good.

In the present invention, an organic compound having a sulfone group in the molecule as a fluidizing agent, such as an alkylaryl sulfonate type, an aromatic polycyclic condensate sulfonate type, a water-soluble melamine formalin sulfonate type,
All commercially available cement water reducers, such as lignin sulfonate, oxyorganic acid salt, polyol, polyoxyethylene alkyl ether, and higher polyhydric alcohols, can be used, especially those containing sulfone in the molecule. By selectively using a compound having a group or an oxyorganic acid salt, the bending strength can be significantly increased. The amount of the cement water reducer added is about 0.1 to 6.0 parts, preferably 0.2 to 4.0 parts, per 100 parts of the raw material.

The drawbacks of slag-based cement include insufficient strength, low surface hardness, large drying shrinkage, and strength loss over long periods of time.The use of the cement water reducer mentioned above is effective in improving these problems. We have discovered that this method can be used in combination with the following substances to make it even better. The substance is a compound containing nitrogen or phosphorus. Nitrogen compounds include amino compounds, diazo compounds, ammonium salts, nitrates, etc.; phosphorus compounds include inorganic phosphates, organic phosphorus compounds, It is a glassy material containing phosphorus, specifically urea or melted phosphorus. The unique effects of using this cement are that it reduces drying shrinkage, improves fluidity, and provides strength equal to or higher than that of ordinary Portland cement. The amount added is based on the raw material
The amount is at most 15 parts per 100 parts, preferably 1 to 10 parts, and the effect will not be enhanced if more is added.

Furthermore, as with ordinary Portland cement, when an organic resin is used in combination, it not only improves chemical resistance such as acid resistance, but also improves adhesive strength, bending strength, and fluidity. Organic resins include natural rubber (MR),
Rubber latex such as chloroprene rubber (CR), styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), methyl methacrylate-butadiene rubber (MBR), butadiene rubber (BR), polyacrylic ester (PAE), polyacetic acid Resin emulsions such as vinyl (PVAC) and its copolymers, vinylidene chloride/vinyl chloride (PVDC), vinyl polypropylene (PVP), epoxy, asphalt, rubber asphalt, paraffin, mixed latexes, mixed emulsions or cellulose derivatives, methyl cellulose ( MC), polyvinyl alcohol (PVA), polyacrylate, furfuryl alcohol, and other water-soluble polymers (monomers), and powdered versions of these may also be added.

The product of the present invention can be used not only in the same fields as ordinary Portland cement, but also in a wider range of fields because it not only has early strength and high strength, but also acid resistance and heat resistance. . For example, it can be used as a lining material for general structures, humid pipes, piles, poles, steel pipe linings, box culverts, etc., as well as marine structures and marine concrete products, as well as lining materials that require acid resistance and heat resistance. .

Examples will be described below.

Example 1 The relationship between the amount of sodium metasilicate added and compressive strength was investigated. The experimental method was a mortar with a cement-sand ratio of 1:2, a cement-water ratio of 40%, and a curing of 20%.
℃, 80% RH, and the specimen size was 4 x 4 x 16 cm.
Measurements were performed in accordance with JIS R5201. The cement used as a raw material consists of 90 parts of granulated blast furnace slag and 10 parts of fly ash, and has a fineness of 5250.
Sodium metasilicate was added to the mixture adjusted to cm ² /g. The results are shown in FIG.

For reference, we conducted a similar test using ordinary Portland cement and found that the material aged 140% in one day.
Kgf/cm ² , 350 kgf/cm ² at 7 days old, 28 days old
It was 450Kgf/ ^cm2 .

From FIG. 1, it can be seen that the binder of the present invention shows significantly superior strength development than ordinary Portland cement.

Example 2 For 100 parts of the same raw material as in Example 1, β-
1 part of a cement water reducer having a polymerization ratio of 4:1 of a formaldehyde condensate of sodium naphthalene sulfonate and sodium gluconate and 2 parts of urea.
and 6 parts of sodium metasilicate as a hardening regulator.
or a mixture of 4 parts of sodium metasilicate and 2 parts of No. 3 sodium silicate. Cement-sand ratio = 1:
2. After mixing the mortar by adjusting the water so that the mortar flow value is 180 ± 10 mm, a 4 x 4 x 16 cm specimen is formed and cured at 20 ° C and 80% RH. Bending strength and drying shrinkage amount was measured. The results are shown in Figures 2 and 3.

In the figure, curve 1 indicates that as a curing regulator,
When using 6 parts of sodium metasilicate, curve 2 is
When using a mixture of 4 parts of sodium metasilicate and 2 parts of No. 3 sodium silicate, and curve 3, 6 parts of sodium metasilicate
This is the case where no cement water reducing agent or urea was added.

As is clear from Figures 2 and 3, the bending strength is improved by using a combination of sodium metasilicate and sodium silicate, or by adding a cement water reducer or urea, rather than using sodium metasilicate alone. It can be seen that the amount of drying shrinkage decreases.

[Brief explanation of drawings]

Figure 1 is a diagram showing the relationship between the amount of sodium metasilicate added and compressive strength, Figure 2 is a diagram showing the relationship between age and bending strength depending on the type of hardening modifier, etc., and Figure 3 is a diagram showing the relationship between age and bending strength depending on the type of hardening modifier. A relationship diagram of the amount of shrinkage is shown.

Claims (1)

[Claims] 1. An inorganic binder characterized by adding 6 to 18 parts by weight of an alkali metasilicate or a substance containing an alkali metasilicate to 100 parts by weight of a fine powder of 2000 cm ² /g or more of brane having latent hydraulic properties.