JPH013042A - Hydraulic inorganic binder and acid fume resistant pipe - 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] [Field of Application in Industry A] The present invention relates to a hydraulic inorganic binder and an acid-resistant hume pipe, and is a high-strength material that is particularly effective for civil engineering construction work or mortar and concrete for concrete products. An energy-saving hydraulic inorganic binder that has excellent acid resistance and can solidify and harden in an appropriate amount of time, and an acid-resistant hume pipe useful as a sewer pipe material, etc., having at least the inner circumferential surface made of the hydraulic inorganic binder. .

[Prior art] Granulated blast furnace slag is quenched with slag water from a blast furnace for producing pig iron, and because it has latent hydraulic properties, it is often used in blast furnace cement, etc., as a low-cost, energy-saving material. It is being

It has been known that when a stimulant such as alkali or gypsum is added to the granulated blast furnace slag powder obtained by crushing the granulated blast furnace slag, the powder develops hydraulic properties and hardens. However, although the cured products obtained in this way generally have superior chemical resistance, especially acid resistance, compared to the cured products of ordinary Portland cement, they have low initial strength and, moreover, after curing, Because it has the disadvantage of gradually disintegrating from the surface over time, it has rarely been put to practical use.

On the other hand, it has been found that the above-mentioned drawbacks can be improved by incorporating an alkali metal hydroxide, alkali metal carbonate, or alkali metal hydrogen carbonate as an alkali stimulant. However, compositions containing such alkaline stimulants set very quickly and solidify immediately after pouring water.
It was difficult to use it as a constituent material for hume tubes, etc.

Therefore, it has been proposed to adjust the setting time by adding an organic acid salt or saccharide as a setting regulator to such a composition (Japanese Patent Publication No. 58-38376).

Note that conventional humid pipes are generally manufactured using cement concrete.

[Problems to be Solved by the Invention] However, in a composition in which an organic acid salt or sugar is added as a setting regulator to a mixture of granulated blast furnace slag powder and an alkaline stimulant, the initial hardening time is the same as that of ordinary Portland cement. However, since the finishing time is long, when applied to centrifugal molded products that require steam curing during the manufacturing process, such as fume tubes, it is necessary to significantly lengthen the pretreatment time, which significantly reduces productivity. . Furthermore, sufficient acid resistance properties cannot be obtained, and hume tubes formed using these materials cannot be expected to significantly improve acid resistance.

In addition, since conventional humid pipes are made of ordinary cement concrete, they still lack acid resistance.

The present invention solves the above-mentioned conventional problems and provides a hydraulic inorganic binder that has setting properties equivalent to ordinary Portland cement and has significantly improved acid resistance, and a humid pipe with excellent acid resistance. The purpose is to

[Means for Solving the Problems] The hydraulic inorganic binder of the present invention comprises granulated blast furnace slag powder 1
0.00 parts by weight, 0.5 to 20 parts by weight of an alkali stimulant, and 0.5 to 15 parts by weight of metal silicofluoride.

In particular, the hydraulic inorganic binder of the present invention has an alkali stimulant selected from the group consisting of alkali metal hydroxides, alkali metal carbonates, and alkali metal hydrogen carbonates or 2f! In addition, it is preferable to use one or more selected from the group consisting of sodium silicofluoride, magnesium silicofluoride, potassium silicofluoride, and calcium silicofluoride as the metal silicofluoride.

Furthermore, the acid-resistant fume pipe of the present invention is characterized in that at least its inner circumferential surface is made of such a hydraulic inorganic binder.

That is, the present inventors have conducted extensive studies in order to provide a hydraulic inorganic binder with an appropriate curing time and excellent properties. By incorporating metal silicofluoride as a setting regulator instead of organic acid salts and sugars, the setting properties are the same as ordinary Portland cement, that is, both the starting time and the finishing time are the same as ordinary Portland cement, and it has high strength. The inventors have also discovered that a cured product with excellent acid resistance can be obtained, and that such a hydraulic inorganic binder can provide extremely excellent acid-resistant hume pipes, thereby completing the present invention.

The present invention will be explained in detail below.

The hydraulic inorganic binder of the present invention comprises granulated blast furnace slag powder 1
00Ii, 0.5 to 20 parts by weight of an alkali stimulant and 0.5 to 15 parts by weight of a metal silicofluoride are blended.

In the present invention, as the granulated blast furnace slag, those used for blast furnace cement can be used.

The higher the fineness of granulated blast furnace slag powder, the better the strength and acid resistance of the resulting cured product. During centrifugal molding of fume tubes and the like, which will be described later, problems occur in moldability, such as a large amount of slag and poor internal tightness. Therefore, from the viewpoint of properties, cost, and formability, the fineness of the granulated blast furnace slag powder should be in the Blaine value range of 2500 to 6000 crn"/g, especially in the range of 3500 to 5000 crn"/g. suitable.

As the alkali stimulant, one or a mixture of two or more of alkali metal hydroxides, alkali metal carbonates, and alkali metal hydrogen carbonates can be used. Examples of the alkali metals of these alkali metal compounds include sodium, potassium, and lithium, and although all of them have the same effect as a stimulant, it is preferable to use sodium compounds in view of economic efficiency.

If the amount of such an alkaline stimulant is less than 0.5 parts by weight per 100 parts of granulated blast furnace slag powder, the effect as a stimulant will be small, and if it exceeds 20 parts by weight, there will be no difference in the effect, so it is not suitable for practical use. Not the point.

Therefore, the amount of the alkaline stimulant to be blended is 0.5 to 20 parts by weight, preferably 2 to 15 parts by weight, per 100 parts by weight of the granulated blast furnace slag powder.

In the present invention, as the metal fluorosilicide, sodium fluorosilicide, potassium fluorosilicide, magnesium fluorosilicide, calcium fluorosilicide, etc. can be used.

If the amount of such metal silicofluoride is less than 0.5 parts by weight per 100 parts by weight of granulated blast furnace slag powder, the effect as a coagulation regulator and the effect of improving strength and acid resistance will be small; Even if it is used in excess, the effect will not increase and it is not practical. Therefore, the amount of metal silicofluoride to be blended is 0.5 to 15 parts by weight, preferably 2 to 10 parts by weight, based on 100 parts by weight of granulated blast furnace slag powder.

The hydraulic inorganic binder of the present invention can be easily produced by mixing granulated blast furnace slag, an alkali stimulant, and a metal silicofluoride in a predetermined ratio, and is extremely useful as a substitute for ordinary Portland cement. be.

The hydraulic inorganic binder of the present invention can be used, for example, to manufacture piles and balls with excellent acid resistance by centrifugal molding, or to manufacture pipes and piles by roll compaction, on-site casting, etc. It can be effectively applied as a constituent material in various fields.

Next, an explanation will be given of the acid-resistant hume pipe of the present invention, in which at least the inner circumferential surface thereof is made of the hydraulic inorganic binder of the present invention.

The acid-resistant fume pipe of the present invention only needs to have at least its inner circumferential surface made of the above-mentioned hydraulic inorganic binder, and its specific structure may be either of the following (1) or (2).

■ The entire structure is composed of the above-mentioned hydraulic inorganic binder.

■ Only the inner peripheral surface is composed of the above-mentioned hydraulic inorganic binder,
The outer circumferential side has a two-layer structure made of ordinary concrete, etc.

For the humid pipe (ii), the above-mentioned hydraulic inorganic binder is used, and the material is compacted by centrifugal force by adding aggregate, water, and a water reducing agent for cement as necessary, and then steam-cured. Therefore, it can be easily manufactured.

In addition, when producing the hume pipe of (■) by centrifugal force forming, first, only ordinary concrete is supplied to form the outer periphery, and then acid-resistant concrete made of the above-mentioned hydraulic inorganic binder is formed. It can be easily manufactured by supplying the inner peripheral part which requires acid resistance.

In this case, the thickness of the inner peripheral part made of acid-resistant concrete is determined appropriately according to the required characteristics of the humid pipe, etc.
By adjusting the amount of acid-resistant concrete to be supplied, it is possible to manufacture a hume pipe having an acid-resistant concrete portion with a desired thickness.

Note that the acid-resistant hume pipe of the present invention may have the same shape, dimensions, etc. as conventional hume pipes, except that at least its inner peripheral surface is made of the hydraulic inorganic binder of the present invention.

[Function] In the hydraulic inorganic binder of the present invention, the granulated blast furnace slag powder rapidly coagulates and solidifies due to the alkaline stimulant, but the coagulation time is controlled by the action of the metal silicofluoride, and the solidification properties (initiation time and final time) are almost the same as ordinary Portland cement. Therefore, it can be suitably used for general construction or concrete products.

Moreover, the strength and acid resistance of the obtained cured product are also improved by adding the metal fluorosilicate. The mechanism of this improvement in strength and acid resistance has not been fully elucidated, but the addition of metal silicofluoride makes the structure denser and prevents the penetration of acid water. It is presumed that due to the production of silicic acid gel, the strength increases and the acid resistance also improves.

In the present invention, in particular, one fil or two or more selected from the group consisting of alkali metal hydroxides, alkali metal carbonates, and alkali metal hydrogen carbonates is used as the alkali stimulant, and sodium silicofluoride is used as the metal fluorosilicide. , one type selected from the group consisting of magnesium fluorosilicide, potassium fluorosilicide, and calcium fluorosilicide, or 2f! By using the above, extremely excellent effects can be obtained.

Therefore, the acid-resistant hume pipe of the present invention has an inner circumferential surface made of a hydraulic inorganic binder that has good coagulation properties and is also extremely excellent in acid resistance, strength, etc. Therefore, ■ The cracking load is significantly improved compared to the case where no metal silicofluoride is added, and the strength is equal to or higher than that when ordinary Portland cement is used.

- Since the acid resistance is significantly improved compared to the case where the material is made of a material that does not contain metal silicofluorides, it can be expected to have great effects as acid-resistant and corrosion-resistant fume pipes, such as sewerage pipe materials.

■ There is almost no cracking or peeling on the inner and outer surfaces of the hume tube, and it has excellent durability.

The effect of improving excellent properties such as

[Examples] Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples unless it exceeds the gist thereof.

Examples 1 to 29, Comparative Examples 1 to 4 The following characteristic tests were conducted on the binders obtained by blending the compositions shown in Table 1 (a) and (b), and the results were summarized in the second table.
They are shown in Tables (a) and (b) and Table 3 (a) and (b).

■ Setting test A setting test was conducted for each binder according to the method specified in "rJIS R5201 Physical Test Methods for Cement."

■ Compressive strength test For mortar obtained by adding 200 parts by weight of acid, parts by weight of wood 35Ii, and 1.2 parts by weight of water reducing agent to 100 parts by weight of each binder and kneading using a Hobart mixer,
A compressive strength test was conducted according to the method specified in JIS R5201.

The method of curing the specimen is as shown below.

Underwater curing = 20°C Underwater steam curing: Pre-curing for 3 hours, temperature increase 20°C/hour Maximum temperature 65°C, duration for 4 hours Natural cooling After steam curing, curing conditions 20°C, 80% RH indoors and testing The tests were carried out for the 7-day wood period and the 28-day wood period, respectively.

(2) Acid resistance test Water-cured and steam-cured specimens prepared under the same conditions as in the above compressive strength test and cured for 28 days were immersed in a 10% sulfuric acid solution at 20° C. for 28 days, and the weight loss of the specimens was examined.

■ Outdoor storage test The following specimens prepared under the same conditions as those for the compressive strength test were left outdoors under the following conditions to examine changes in surface condition.

Specimen: 20℃ for 28 days after steam curing, Cured under 80%RH conditions of.

Conditions of storage: 6 months left outside ■Change in flow value over time■ Mortar prepared under the same conditions as the compressive strength test was subjected to a flow test after 30 minutes, 1 hour, 1.5 hours, and 2 hours of kneading. JIS that investigated changes over time
Measurement was performed according to the method specified in R5201.

Table 1 (a), (b), Table 2 (a), (b) and Table 3
The following is clear from Tables (a) and (b).

That is, by adding an alkali stimulant and a metal fluorosilicate to the granulated blast furnace slag powder, the setting time and the change in flow value over time are adjusted to a suitable range, making it equivalent to ordinary Portland cement. Therefore, the compressive strength of the resulting hardened product is significantly higher than that of specimens using sodium gluconate or sucrose as a setting control agent, and even higher than that of ordinary Portland cement. In addition, acid resistance has also been significantly improved.

In addition, in the outdoor storage test, no peeling or disintegration from the surface was observed in any of the specimens.

In the Examples and Comparative Examples, the raw materials used were as follows.

Granulated blast furnace slag powder nibrene value 4280c rd/
g Sodium hydroxide: Reagent grade sodium carbonate ・〃 Sodium hydrogen carbonate: 〃 Sodium silicofluoride: Reagent grade 1 potassium silicofluoride: Chemical reagent magnesium silicofluoride: Reagent grade sodium gluconate: Chemical reagent sucrose
Commercial white sugar sand Dry fine sand water reducing agent Mighty 150 Table 3 (a
> Table 3 (b) Examples 30 to 39, Comparative Examples 5 to 7 Using the binder with the composition shown in Table 4, concrete was mixed according to the concrete composition shown in Table 5, and a humid pipe with the specifications shown below was prepared. was molded.

Huyum tube specifications [For external pressure test] Nominal diameter: 350mm Pipe thickness: 30mm Effective length: 2000mm Shape 2 B type Reinforcement specifications: Spiral reinforcement = φ3.2mm ×Pitch 45mm Reinforcement ratio = 0.559% Vertical lines = φ4mm x 12 pieces [Acid resistance test kit] Nominal diameter: 250mm Pipe thickness: 28mm Effective length: 300mm Shape = A shape Reinforcement specifications: Spiral reinforcement = φ2.6mm ×Pitch 55mm Reinforcement ratio = 0.345% Vertical line = φ3.2mm x 10 pieces Table 5 Note that the centrifugal force molding conditions were as shown in FIG.

After molding, steam curing was performed under the conditions shown below, and after demolding, air curing was performed.

Steam curing conditions Pre-curing = 3 hours Temperature increase 20°C/hour Maximum temperature: 65°C Dark duration: 3 hours Natural cooling Using the obtained hume tubes, the following various tests were conducted. The results are shown in Table 6.

■ External pressure test For each external pressure test hume pipe, an external pressure test was conducted on the 14th day of the material age according to the method specified in rJIsA5305 Centrifugal Force Reinforced Concrete Pipe.

■ Acid resistance test Stand the hume tube for each acid resistance test on a plastic plate.
Glue the hump tube and plastic plate with epoxy resin,
From the 14th day of age, add 5% sulfuric acid solution to a depth of 250mm.
The solution was replaced every week with a lid on top, and weight loss and deterioration of the inner surface were observed after 28 days.

■ Outdoor test A Hume tube produced under the same conditions as the external pressure test was left outdoors for 6 months immediately after demolding, and changes in the inner and surface conditions were examined.

Table 6 *　○: No cracking or peeling at all.

△: Cracks! IJ fi is slightly present.

×: Many cracks and flaking.

The following is clear from these test results.

The cracking load of the acid-resistant hume pipe of the present invention (with a width of 0.0
The value obtained by dividing the load indicated by the testing machine by the effective length when a crack of 5 mm occurs) is significantly increased compared to the conventional one containing organic acid and sucrose (Comparative Example 5.6), Even when compared with the Huyum tube formed using Portland cement (Comparative Example 7), it shows a value equal to or higher than that. In addition, the cracking load of the acid-resistant humid pipe of the present invention is a nominal diameter of 350 mm.
JIS standard for cracking load of external pressure pipe 1 (2, OOO
Kgf/m). In those to which organic acid and sucrose were added (Comparative Examples 5 and 6), pseudo-setting was significantly delayed and the strength decreased due to insufficient pre-curing with steam curing, but such adverse effects are not observed at all in the present invention.

In addition, after 28 days of immersion, the acid-resistant hume tube of the present invention showed a significant weight loss with the one made of ordinary Portland cement (Comparative Example 7), while almost no change was observed, and with the conventional organic acid and sucrose added (Comparative Example 5)
．． The acid resistance is significantly improved compared to 6). The corrosion situation on the inner surface of the ordinary Portland cement hump pipe (
In Comparative Example 7), the paste layer and mortar layer on the inner surface of the hume pipe were eroded, and the coarse aggregate was exposed, and the paste layer was also eroded in the cases in which organic acid and sucrose were added (Comparative Example 5.6). On the other hand, almost no change was observed in the Huyum's canal of the present invention.

Further, in an external appearance examination of the hume tube after being left outdoors for six months, the acid-resistant hume tube of the present invention showed no abnormalities such as cracking or peeling, and was confirmed to have extremely excellent durability.

[Effects of the Invention] As detailed above, the hydraulic inorganic binder of the present invention is made by adding metal fluorosilicate to granulated blast furnace slag powder as an alkali stimulant and a coagulation regulator. By adding metal fluorosilicate as a setting regulator instead of organic acid salts and sugars, (1) setting time can be adjusted to a suitable range, and both starting time and finishing time are very good, comparable to ordinary Portland cement.

■ The compressive strength of the resulting cured product increases significantly, making it even stronger than ordinary Portland cement.

■ The acid resistance of the cured product is also significantly improved.

■ There is no peeling or disintegration of the surface of the cured product, and it has excellent durability.

■ The change in flow value over time is equivalent to that of ordinary Portland cement, and it provides suitable pouring workability.

The effect of improving excellent properties such as Therefore, the hydraulic inorganic binder of the present invention is extremely useful as a constituent material for civil engineering and architectural structures, particularly for structures that require acid resistance.
Its industrial and economic value is extremely high.

In particular, in the present invention, one or more selected from the group consisting of alkali metal hydroxides, alkali metal carbonates, and alkali metal hydrogen carbonates are used as the alkali stimulant, and sodium silicofluoride is used as the metal silicofluoride. , one or two selected from the group consisting of magnesium fluorosilicide, potassium fluorosilicide, and calcium fluorosilicide
A significantly superior effect can be obtained by using fili or more.

Therefore, the acid-resistant hume pipe of the present invention has at least its inner peripheral surface made of such an excellent hydraulic inorganic binder, and has extremely excellent acid resistance, high strength, and durability. In addition to being expensive, it has excellent productivity and is extremely useful industrially as pipe material for sewerage, etc.

[Brief explanation of drawings]

FIG. 1 is a diagram showing conditions for centrifugal force forming of hume tubes in Examples 30 to 39 and Comparative Examples 5 to 7.

Claims (3)

[Claims] (1) 100 parts by weight of granulated blast furnace slag powder, 0.5 to 20 parts by weight of an alkali stimulant, and 0.5 to 15 parts by weight of metal silicofluoride
A hydraulic inorganic binder characterized by containing parts by weight. (2) The alkali stimulant is one or more selected from the group consisting of alkali metal hydroxides, alkali metal carbonates, and alkali metal hydrogen carbonates, and the metal silicofluoride is sodium silicofluoride or magnesium silicofluoride. The hydraulic inorganic binder according to claim 1, wherein the hydraulic inorganic binder is one or more selected from the group consisting of , potassium fluorosilicide, and calcium fluorosilicide. (3) An acid-resistant fume tube, characterized in that at least the inner circumferential surface thereof is made of the hydraulic inorganic binder according to claim 1.