JP5659050B2 - Expansion inhibitor for concrete aggregate and expansion-suppressed concrete aggregate using the same - Google Patents

Description

  The present invention relates to an expansion inhibitor for concrete aggregate that is used when the molten slag aggregate is effectively used as an aggregate during concrete production such as a retaining wall or a U-shaped side groove, and an expansion suppression concrete bone using the same. It relates to materials.

  In this specification, the term “concrete” is used to mean “concrete and mortar”.

  Conventionally, for example, incineration ash and waste slag such as waste incineration ash, RDF ash (garbage solidified fuel incineration ash), and waste incineration ash molten slag can be reused without being discarded. It has been used as an aggregate, admixture, etc. of hardened cement.

  Generally, when molten slag is used as an aggregate such as fine aggregate or coarse aggregate for concrete, metal aluminum contained in the molten slag reacts with alkali components in the cement to generate hydrogen, and concrete. Hydrogen remains as bubbles in the concrete, and the concrete expands, resulting in a decrease in strength.

  Here, in plasma melting or burner melting, a part of the metal aluminum in the treated ash moves into the slag, and when it is large, it reaches several percent. When such slag is used for concrete aggregate, concrete expands and strength decreases, so it is difficult to effectively use slag aggregate.

  The metallic aluminum in the slag, which is the main causative agent of concrete expansion, can be removed about 80% of the bulk metallic aluminum by aluminum sorting etc., but only about 10-20% of the fine metallic aluminum can be removed. .

  The expansion of concrete by metal aluminum is greatly affected by fine metal aluminum having a large surface area, and there has been a problem that the effect of suppressing the expansion of concrete is small in the removal process of metal aluminum in the slag by aluminum sorting.

  By the way, in so-called gasification and melting, metallic aluminum is selectively removed from the gasification furnace residue, and the aluminum content in the melting furnace hardly goes, so the metallic aluminum in the slag is 0.1% by weight or less, and the gasification and melting slag is reduced. Even if it is used as a concrete fine aggregate, the concrete does not expand or lose its strength.

  Patent Documents 1 and 2 listed below describe an expansion inhibitor for cement compositions and a cement composition in which nitrates and nitrites of alkali metals or alkaline earth metals are combined.

  Further, Patent Document 3 discloses a molten slag treatment facility and a molten slag treatment method using this facility, and a molten slag containing metallic aluminum is subjected to an alkaline treatment at a pH of 10 to 14 on a slag conveyor line, and then at a pH of 5 to 5. Wash with 7 acid. It is described that an oxide film is formed on the surface of metal aluminum by alkali treatment to suppress expansion due to hydrogen generation during the production of a cement composition.

  Furthermore, Patent Document 4 discloses a method for treating waste molten slag, in which molten slag containing metallic aluminum is treated with hydrogen peroxide, ozone, salash powder, sodium hypochlorite, chlorine dioxide, or permanganese. An extremely general method for forming an oxide film on the surface of metal aluminum by treatment with an oxidizing agent such as potassium acid is described.

JP 2002-326853 A JP 2007-106651 A JP 2008-105897 A Japanese Patent Laid-Open No. 10-137717

  The expansion inhibitors described in Patent Documents 1 and 2 above are excellent in expansion suppression effect and are already commercially available, but have a problem that the price is very high. In addition, according to the molten slag treatment method of Patent Document 3, hydrogen is generated during the alkali treatment of the slag conveyor line of the metal aluminum-containing molten slag, so measures to prevent ignition of the generated hydrogen are necessary, and the equipment cost is high. There was a problem of sticking. Furthermore, the waste molten slag treatment method of Patent Document 4 has the following problems with respect to the oxidizing agent used, and there is a problem that its use is undesirable.

Hydrogen peroxide: A powerful and toxic substance Ozone: Acute and chronic toxic to human body Sarashi powder, sodium hypochlorite, chlorine dioxide: Strong oxidizing power but corrosive potassium permanganate : PRTR target substance (first type designated chemical substance) The object of the present invention is to solve the above-mentioned problems of the prior art and form a sparingly soluble protective film on the surface of the metal aluminum in the molten slag aggregate. It is possible to detoxify fine metal aluminum, and there is no generation of hydrogen when forming a poorly soluble protective film, and at low cost, it can reliably suppress the expansion of concrete even when used as a concrete aggregate. An object of the present invention is to provide an expansion inhibitor for concrete aggregate, and an expansion-inhibited concrete aggregate using the same.

  In order to achieve the above object, an expansion inhibitor for concrete aggregate according to claim 1 of the present invention is an expansion inhibitor used for a concrete aggregate made of a molten aluminum-containing molten slag aggregate, and is an alkali metal. And / or an alkaline earth metal acetate.

  Here, the alkali metal is preferably potassium or sodium. The alkaline earth metal is preferably calcium and / or magnesium.

  In the expansion-suppressed concrete aggregate according to claim 4 of the present invention, the molten aluminum-containing molten slag aggregate is treated with the above-described expansion suppressant for concrete aggregate to obtain an acetic acid of alkali metal and / or alkaline earth metal. A protective film made of an insoluble basic aluminum acetate film is formed on the surface of metallic aluminum in the slag aggregate by the action of the salt.

  The invention of a concrete aggregate expansion inhibitor according to claim 1 is an expansion inhibitor used for a concrete aggregate made of a molten aluminum-containing molten slag aggregate, and includes an alkali metal and / or alkaline earth metal acetate. According to the invention of claim 1, the molten slag aggregate is mixed with an alkali metal or alkaline earth metal acetate salt (potassium acetate, sodium acetate, calcium acetate, and magnesium acetate calcium (CMA). ) To form a protective film made of an insoluble basic aluminum acetate film on the surface of the metal aluminum in the slag aggregate, thereby detoxifying the fine metal aluminum. The treated slag aggregate Generation of hydrogen by reaction with alkali components in cement when used as a concrete aggregate Preventing, together with the expansion of the concrete can be suppressed to 2% or less appropriate value, it is possible to suppress the reduction in the strength of the concrete, yet there is an effect that a very low cost.

  The invention of the expansion-suppressed concrete aggregate according to claim 4 is characterized in that the molten aluminum-containing molten slag aggregate is treated with the above-described expansion inhibitor for concrete aggregate, and the action of an alkali metal and / or alkaline earth metal acetate Thus, a protective coating made of an insoluble basic aluminum acetate coating is formed on the surface of the metallic aluminum in the slag aggregate. According to the invention of claim 4, the expansion-suppressed concrete aggregate When used as a component of concrete, hydrogen generation due to reaction with alkali components in the cement can be prevented, expansion and strength reduction of the concrete can be suppressed, and the cost is extremely low. .

  Next, embodiments of the present invention will be described, but the present invention is not limited thereto.

 The expansion inhibitor for concrete aggregate according to the present invention is an expansion inhibitor used for a concrete aggregate made of a molten aluminum-containing molten slag aggregate, and includes an alkali metal and / or alkaline earth metal acetate. It is said.

  That is, the present invention provides a method for treating molten slag aggregate with an alkali metal or alkaline earth metal acetate salt (potassium acetate, sodium acetate, calcium acetate, and magnesium acetate / calcium (CMA)). By forming a protective coating made of an insoluble basic aluminum acetate coating on the surface of the metallic aluminum, the fine metallic aluminum can be made harmless. When the treated slag aggregate is used as a concrete aggregate, Hydrogen generation due to the reaction with the alkali components therein can be prevented, expansion and strength reduction of the concrete can be suppressed, and the cost is very low.

  The present inventor believes that magnesium and zinc are dissolved in acetic acid, but aluminum is not dissolved in acetic acid, that is, aluminum acetate is produced by reaction with acetic acid, but immediately changes to slightly soluble basic aluminum acetate. Metallic aluminum, which is an amphoteric metal, generates hydrogen when dissolved with acid or alkali, etc., so that metal aluminum in slag aggregate is treated with a compound near weak alkali from weak acid to generate hydrogen. Without searching for a substance that suppresses the expansion of the concrete composition when it is used as a concrete aggregate by forming a hardly soluble film in water, an alkali metal or alkaline earth metal acetate was found.

  First, examples of the molten slag to which the concrete aggregate expansion inhibitor of the present invention is applied include molten slag such as waste incinerated ash molten slag, RDF ash (garbage solidified fuel incinerated ash) molten slag, and the like.

  These molten slags usually have a particle size of 5 mm or less when used as concrete slag fine aggregates (MS5 in the JIS standard for molten slag fine aggregates, and other than this, MS2.5, MS1.2, MS5-0 .3 etc.) are used after being crushed. The molten slag may be used as a coarse slag aggregate for concrete having a particle size exceeding 5 mm. The metal aluminum content of the molten slag varies and varies depending on the type of melting furnace. In general, many are in the range of 0.05 to 0.5% by weight. The metallic iron content is defined as 1% or less according to JIS standards.

  The expansion inhibitor for concrete aggregate of the present invention is an expansion inhibitor used for a concrete aggregate composed of these metal aluminum-containing molten slag aggregates, and includes an alkali metal and / or alkaline earth metal acetate, Since its pH is from 7.1 to 8.8 neutral to weakly alkaline, an insoluble film is formed without generating hydrogen.

  Then, the above-described pulverized particulate molten slag is sprayed with the concrete aggregate expansion inhibitor of the present invention, mixed and added, and then the mixture is dried to produce an expansion-suppressed concrete aggregate.

 The method for producing concrete or mortar using the expansion inhibitor for concrete aggregate of the present invention has the following four embodiments.

 First, the first method sprays an aqueous solution of an alkali metal and / or alkaline earth metal acetate which is an expansion inhibitor for concrete aggregate of the present invention on the pulverized particulate molten slag aggregate. After the addition of the mixture, the mixture is heated and dried to produce the expansion-suppressed concrete aggregate of the present invention. Next, the expansion-suppressed concrete aggregate, cement, water, and AE water reducing agent are blended at a predetermined ratio and kneaded into a paste to produce concrete or mortar.

  Next, in the second method, an aqueous solution of an alkali metal and / or alkaline earth metal acetate which is the expansion inhibitor for concrete aggregate of the present invention is applied to the pulverized particulate molten slag aggregate. After spraying, mixing and adding, the mixture is allowed to stand at room temperature without heating for a required time and dried to produce the expansion-suppressed concrete aggregate of the present invention. Next, the expansion-suppressed concrete aggregate, cement, water, and AE water reducing agent are blended at a predetermined ratio and kneaded into a paste to produce concrete or mortar.

  In the third method, the pulverized particulate molten slag aggregate is added to the aqueous solution of alkali metal and / or alkaline earth metal acetate which is the expansion inhibitor for concrete aggregate of the present invention at a predetermined ratio. Then, the mixture is allowed to stand at room temperature for a required time to produce an expansion-suppressed concrete aggregate dispersion aqueous solution. Next, the expansion-suppressed concrete aggregate-dispersed aqueous solution, cement, and AE water reducing agent are blended at a predetermined ratio and kneaded into a paste to produce concrete or mortar.

  Furthermore, the fourth method is a method in which the pulverized particulate molten slag aggregate is added to the aqueous solution of the alkali metal and / or alkaline earth metal acetate which is the expansion inhibitor for concrete aggregate of the present invention at a predetermined ratio. To obtain an expansion-suppressed concrete aggregate-dispersed aqueous solution, and then immediately add cement and an AE water reducing agent to the expansion-suppressed concrete aggregate-dispersed aqueous solution at a predetermined ratio to form a paste. Kneading to produce concrete and mortar.

  In the first method for producing concrete and mortar using the concrete aggregate expansion inhibitor of the present invention, the concrete aggregate expansion of the present invention is applied to the pulverized particulate molten slag aggregate. Since the aqueous solution of the alkali metal and / or alkaline earth metal acetate which is the inhibitor is sprayed and mixed and added, the mixture is heated and dried to produce the expansion-suppressed concrete aggregate of the present invention. There is an advantage that a protective film made of an insoluble basic aluminum acetate film is surely formed on the surface of metal aluminum in the molten slag aggregate by the action of alkali metal and / or alkaline earth metal acetate. . And this expansion suppression concrete aggregate, cement, water, and AE water reducing agent are mix | blended in a predetermined ratio, knead | mixed in paste form, and it manufactures concrete and mortar, and with an alkali component in cement, Hydrogen generation due to the reaction can be prevented, the expansion of the concrete can be reliably suppressed to an appropriate value of 2% or less, and a decrease in the strength of the concrete can be suppressed.

 Next, in the second method for producing concrete or mortar using the concrete aggregate expansion inhibitor of the present invention, the pulverized particulate molten slag aggregate is used for the concrete aggregate of the present invention. After spraying an aqueous solution of an alkali metal and / or alkaline earth metal acetate as an expansion inhibitor, mixing and adding, the mixture is allowed to stand at room temperature without heating and dried, and the expansion-inhibited concrete bone of the present invention Since the material is manufactured, there is an advantage that a heating step is unnecessary. Moreover, a protective film made of an insoluble basic aluminum acetate film is formed on the surface of the metal aluminum in the molten slag aggregate by the action of the alkali metal and / or alkaline earth metal acetate. And this expansion suppression concrete aggregate, cement, water, and AE water reducing agent are mix | blended in a predetermined ratio, knead | mixed in paste form, and it manufactures concrete and mortar, and with an alkali component in cement, Hydrogen generation due to the reaction can be prevented, the expansion of the concrete can be reliably suppressed to an appropriate value of 2% or less, and a decrease in the strength of the concrete can be suppressed.

  In the third method for producing concrete or mortar using the expansion inhibitor for concrete aggregate of the present invention, an alkali metal and / or alkaline earth metal acetate which is the expansion inhibitor for concrete aggregate of the present invention. After the pulverized particulate molten slag aggregate is added to and dispersed in the aqueous solution at a predetermined ratio, it is allowed to stand at room temperature for a required time to produce an expansion-suppressed concrete aggregate-dispersed aqueous solution. There is an advantage that a process is not necessary, and in the state of a concrete aggregate dispersed aqueous solution, an alkali metal and / or alkaline earth metal acetate acts to make the base insoluble in the surface of the metal aluminum in the molten slag aggregate. A protective film made of a functional aluminum acetate film is formed. And this expansion suppression concrete aggregate dispersion aqueous solution, cement, and AE water reducing agent are mix | blended in a predetermined ratio, knead | mixed in paste form, and it manufactures concrete and mortar, and with the alkali component in cement, Hydrogen generation due to the reaction can be prevented, the expansion of the concrete can be reliably suppressed to an appropriate value of 2% or less, and a decrease in the strength of the concrete can be suppressed.

  Furthermore, in the fourth method for producing concrete or mortar using the expansion inhibitor for concrete aggregate of the present invention, the alkali metal and / or alkaline earth metal which is the expansion inhibitor for concrete aggregate of the present invention is used. In an aqueous solution of acetate, pulverized particulate molten slag aggregate is added and dispersed at a predetermined ratio to obtain an expansion-suppressed concrete aggregate-dispersed aqueous solution, and then immediately into the expansion-suppressed concrete aggregate-dispersed aqueous solution. , Cement, and AE water reducing agent are blended at a predetermined ratio and kneaded into a paste to produce concrete and mortar, which eliminates the need for a heating process and greatly increases the production time of concrete and mortar. There is an advantage that it can be shortened. Of course, in the state of the concrete aggregate dispersed aqueous solution, a protective film made of an insoluble basic aluminum acetate film is formed on the surface of the metal aluminum in the molten slag aggregate by the action of alkali metal and / or alkaline earth metal acetate. It is formed, prevents hydrogen generation due to reaction with alkali components in cement, can reliably suppress the expansion of concrete to an appropriate value of 2% or less, and can suppress a decrease in strength of concrete. Is.

 In addition, the expansion test about the concrete and mortar produced using the expansion inhibitor for concrete aggregates by this invention is performed based on the appendix 1 of JISA5031, and the expansion coefficient of a test piece is measured.

 According to the expansion inhibitor for concrete aggregates of the present invention, in any of the above cases, basicity that is insoluble on the surface of metallic aluminum in the slag aggregates due to the action of alkali metal and / or alkaline earth metal acetates. A protective film made of an aluminum acetate film is formed, and there is no generation of hydrogen when forming a protective film made of the insoluble basic aluminum acetate film, and the film is formed on the surface of metallic aluminum in the molten slag aggregate at a low cost. Can be made.

 When the expansion-suppressed concrete aggregate according to the present invention is used as a component of concrete, hydrogen generation due to reaction with alkali components in the cement is prevented, and the expansion of the concrete is surely suppressed to an appropriate value of 2% or less. It is possible to reduce the strength of the concrete, and the cost is very low.

  Next, examples of the present invention will be described together with comparative examples, but the present invention is not limited to these examples.

Example 1
Of the above-mentioned four embodiments for producing mortar using the expansion inhibitor for concrete aggregates of the present invention, the first method is used.

 That is, after spraying, mixing and adding an aqueous solution of alkali metal and / or alkaline earth metal acetate, which is the expansion inhibitor for concrete aggregate of the present invention, to the pulverized particulate molten slag aggregate The mixture is heated and dried to produce the expansion-suppressed concrete aggregate of the present invention. Next, this expansion suppression concrete aggregate, cement, water, and an AE water reducing agent were blended at a predetermined ratio and kneaded into a paste to produce a mortar.

  First, 1350 g of waste incineration ash plasma molten slag aggregate pulverized to a particle size of 5 mm or less was prepared. The molten aluminum slag aggregate had a metal aluminum content of 0.16% by weight and a metal iron content of 0.32% by weight.

  Next, this plasma molten slag aggregate was put into a stainless steel square bat of about 5 liters, and an aqueous calcium acetate solution having a concentration of 0.2 mol / L (3.16% by weight) was used as an expansion inhibitor for concrete aggregates of the present invention. (PH: 7.4) 67.5 g was sprayed and mixed. Thereafter, the mixture was dried at a temperature of 105 ° C. for 2 hours to produce a concrete fine aggregate.

  Here, the numerical value in () of 0.2 mol / L (3.16% by weight) represents the numerical value obtained by converting the molar concentration of calcium acetate in the aqueous calcium acetate solution into the weight concentration.

 And when the addition amount (weight%) of the expansion inhibitor with respect to slag aggregate was calculated from this weight concentration, it was 0.158 weight%.

<Mortar expansion test>
Subsequently, mortar was manufactured using the above-mentioned concrete fine aggregate according to the present invention, and a mortar expansion test was performed. Here, the mortar expansion test was conducted based on Annex 1 of JIS A 5031.

  1350 g of drug-treated concrete fine aggregate (particle size of 5 mm or less) according to the present invention, 1200 g of Portland cement, 540 g of water, and 60 g of AE water reducing agent (those diluted to 1/10 of the stock solution) are kneaded into a paste. A mortar was prepared. Subsequently, this mortar kneaded material was filled up to about 200 mm in a polyethylene bag of length 550 mm × diameter 50 mm × thickness 0.05 mm, and placed in a 1 L graduated cylinder containing 400 mL of water. The bag was lowered until the water surface of the graduated cylinder coincided with the mortar surface in the bag, and 400 mL was subtracted from the reading of the graduated cylinder at this time to obtain the volume V1 (mL) of the mortar. And the upper end of the bag was tied, this was hung and it left still at room temperature for 24 hours, and was solidified.

  After solidification, the mortar test piece is put into a 1 L graduated cylinder containing 400 mL of water in the same manner as before, and the bag is lowered until the water surface of the graduated cylinder and the mortar surface put in the bag coincide with each other. The volume V2 (mL) of the mortar after solidification was determined by subtracting 400 mL from the reading, and the mortar expansion rate was determined by the following formula.

   Mortar expansion rate (%) = (V2−V1) / V1 × 100.

 In addition, the average value of three specimens was used for the mortar expansion rate.

  Table 1 below shows the measurement results of the expansion rate of the obtained mortar specimens, the types of expansion inhibitors, the concentration of the expansion inhibitor solution, the pH, and the amount of expansion inhibitor added to the slag aggregate (% by weight). It was shown to.

Examples 2-6
In the same manner as in Example 1, the mortar is produced using the expansion inhibitor for concrete aggregate of the present invention, but the type of the expansion inhibitor of the present invention and the concentration of the expansion inhibitor solution are variously changed. And implemented.

  Here, in Example 2, 0.4 mol / L (6.32 wt%) calcium acetate (pH: 7.7) was used.

  In Example 3, 0.6 mol / L (9.48% by weight) of calcium acetate (pH: 8.0) was used.

  In Example 4, CMA (calcium / magnesium / acetate) 0.2 mol / L (2.94 wt%) (pH: 8.1) was used.

  In Example 5, CMA 0.4 mol / L (5.88 wt%) (pH: 8.3) was used.

  In Example 6, CMA 0.6 mol / L (8.82 wt%) (pH: 8.4) was used.

  In Example 7, 0.6 mol / L of potassium acetate (5.89% by weight) (pH: 8.5) was used.

  In Example 8, 0.6 mol / L (4.92% by weight) of sodium acetate (pH: 8.5) was used.

  CMA is calcium / magnesium / acetate (Ca: Mg molar ratio = 3: 7).

  Using these concrete aggregate expansion inhibitors of the present invention, various concrete fine aggregates according to the present invention were prepared in the same manner as in Example 1 above.

  Subsequently, using the obtained concrete fine aggregates of Examples 2 to 8, a mortar was produced in the same manner as in Example 1, and a mortar expansion test was performed. The obtained results are shown in Table 1 below.

Comparative Examples 1-3
For comparison, the following three experiments were performed.

  First, in Comparative Example 1, only water (pH: 7.0) was sprayed on the waste incineration ash plasma molten slag aggregate used in Example 1 without using an expansion inhibitor. , Mixed and added. Thereafter, the mixture was dried in the same manner as in Example 1 to produce a concrete fine aggregate.

  Next, in Comparative Example 2, a concrete fine aggregate was used in the same manner as in Example 1 above, using a conventional slaked lime saturated aqueous solution (0.25 wt%) (pH: 13.0) as an expansion inhibitor. Was made.

  In Comparative Example 3, a concrete fine aggregate was used in the same manner as in Example 1 above, using a conventional aqueous hydrogen peroxide solution (3.10% by weight) (pH: 7.2) as an expansion inhibitor. Produced.

Subsequently, using the obtained mortar fine aggregates of Comparative Examples 1 to 3, a mortar was produced in the same manner as in Example 1, and a mortar expansion test was performed. The obtained results are shown in Table 1 below.

  As is clear from the results of Table 1 above, according to Examples 1 to 8 of the present invention, mortar is manufactured using a concrete fine aggregate made of plasma molten slag aggregate treated with the expansion inhibitor of the present invention. In addition, by performing the mortar expansion test, it is possible to suppress the expansion rate of the mortar specimen, and there is an advantage that the cost is less than half the price as compared with a commercially available mortar expansion inhibitor. On the other hand, according to Comparative Examples 1 to 3, the mortar specimen has a high expansion coefficient, and the metal aluminum contained in the plasma molten slag aggregate reacts with the alkali component in the cement to generate hydrogen, There was a problem that hydrogen remained in the concrete as bubbles, and the mortar expanded, resulting in a decrease in strength.

Examples 9-14
In the same manner as in Example 1, the concrete fine aggregate of the present invention was prepared. As the molten slag aggregate, burner slag aggregate of incinerated ash pulverized to a particle size of 5 mm or less was used. The burner molten slag aggregate had a metal aluminum content of 0.19% by weight and a metal iron content of 0.26% by weight.

  In addition, the kind of expansion inhibitor of this invention in Examples 9-14 and the density | concentration of the expansion inhibitor solution were made the same as the case of the said Examples 1-6.

  Subsequently, using the obtained concrete fine aggregates of Examples 9 to 14, a mortar was produced in the same manner as in Example 1, and a mortar expansion test was performed. Table 2 below shows the measurement results of the expansion rate of the obtained mortar specimens, the types of the expansion inhibitors, the concentration of the expansion inhibitor solution, the pH, and the amount (% by weight) of the expansion inhibitor added to the slag aggregate. It was shown to.

Comparative Example 4
For comparison, water (pH: 7.0) was sprayed and mixed and added to the waste incineration ash burner molten slag aggregate used in Example 9 to a particle size of 5 mm or less. Thereafter, the mixture was dried in the same manner as in Example 1 to produce a concrete fine aggregate.

Subsequently, using the obtained concrete fine aggregate of Comparative Example 4, a mortar was produced in the same manner as in Example 1, and a mortar expansion test was performed. The obtained results are shown in Table 2 below.

  As is clear from the results in Table 2 above, according to Examples 9 to 14 of the present invention, mortar is produced using a concrete fine aggregate made of burner molten slag aggregate treated with the expansion inhibitor of the present invention. In addition, by performing the mortar expansion test, it is possible to suppress the expansion rate of the mortar specimen, and there is an advantage that the cost is less than half the price as compared with a commercially available mortar expansion inhibitor. On the other hand, according to Comparative Example 4, the expansion rate of the mortar test piece was high.

Examples 15-20
In the same manner as in Example 1, the concrete fine aggregate of the present invention was produced. As the molten slag aggregate, plasma incinerated ash slag aggregate pulverized to a particle size of 5 mm or less was used. The plasma molten slag aggregate had a metal aluminum content of 0.15% by weight and a metal iron content of 0.40% by weight.

  In addition, the kind of expansion inhibitor of this invention in Examples 15-20 and the density | concentration of the expansion inhibitor solution were made the same as the case of the said Examples 1-6.

 Subsequently, using the obtained concrete fine aggregates of Examples 15 to 20, a mortar was produced in the same manner as in Example 1, and a mortar expansion test was performed. Table 3 below shows the measurement results of the expansion rate of the obtained mortar specimens, the types of expansion inhibitors, the concentration of the expansion inhibitor solution, the pH, and the amount of expansion inhibitor added to the slag aggregate (% by weight). Indicated.

Comparative Example 5
For comparison, water (pH: 7.0) was sprayed and mixed and added to the waste incinerated ash plasma molten slag aggregate used in Example 15 and pulverized to a particle size of 5 mm or less. Thereafter, the mixture was dried in the same manner as in Example 1 to produce a concrete fine aggregate.

Subsequently, using the obtained concrete fine aggregate of Comparative Example 5, a mortar was produced in the same manner as in Example 1, and a mortar expansion test was performed. The obtained results are shown in Table 3 below.

  As is clear from the results of Table 3 above, according to Examples 15 to 20 of the present invention, mortar was produced using a concrete fine aggregate made of plasma molten slag aggregate treated with the expansion inhibitor of the present invention. In addition, by performing the mortar expansion test, it is possible to suppress the expansion rate of the mortar specimen, and there is an advantage that the cost is less than half the price as compared with a commercially available mortar expansion inhibitor. On the other hand, according to Comparative Example 5, the expansion rate of the mortar test piece was high.

Example 21
Of the above four embodiments for producing mortar using the concrete aggregate expansion inhibitor of the present invention, the second method is used.

  That is, sprayed with an aqueous solution of calcium acetate, which is an expansion inhibitor for concrete aggregates of the present invention, to the pulverized particulate molten slag aggregate, mixed and added, and then allowed to stand at room temperature without heating for a required time. And drying to produce the expansion-suppressed concrete aggregate of the present invention. Next, this expansion suppression concrete aggregate, cement, water, and an AE water reducing agent were blended at a predetermined ratio and kneaded into a paste to produce a mortar.

  First, 1350 g of waste incineration ash burner molten slag pulverized to a particle size of 5 mm or less was prepared. This molten slag had a metal aluminum content of 0.20% by weight and a metal iron content of 0.11% by weight.

  Subsequently, this burner molten slag was put into a stainless steel square bat of about 5 liters, and an aqueous calcium acetate solution (pH of 0.6 mol / L (9.48% by weight)) was used as an expansion inhibitor for mortar aggregates of the present invention. : 8.0) 67.5 g was sprayed and mixed. Thereafter, the mixture was allowed to stand at room temperature (about 10 ° C. at the time of the test) for 16 hours and dried to produce the expansion-suppressed concrete fine aggregate of the present invention.

  And when the addition amount (weight%) of the expansion inhibitor with respect to slag was calculated from this weight concentration, it was 0.472 weight%.

 Subsequently, using the above-mentioned concrete fine aggregate according to the present invention, a mortar was produced in the same manner as in Example 1, and a mortar expansion test was performed. Table 4 below shows the measurement results of the expansion rate of the obtained mortar specimens, the types of the expansion inhibitor, the concentration of the expansion inhibitor aqueous solution, the pH, and the addition amount (% by weight) of the expansion inhibitor relative to the slag aggregate. It was shown to.

Example 22
By the same method as in Example 21 above, mortar is produced using the concrete aggregate expansion inhibitor of the present invention, but calcium acetate 1.2 mol / L (18.96 wt%) (pH: 8.3). )It was used. From this weight concentration, the amount of expansion inhibitor added to the slag (% by weight) was calculated to be 0.944% by weight.

Subsequently, using the above-mentioned concrete fine aggregate according to the present invention, a mortar was produced in the same manner as in Example 1, and a mortar expansion test was performed. The obtained results are shown in Table 4 below.

  As is apparent from the results in Table 4 above, according to Examples 21 and 22 of the present invention, mortar was produced using a concrete fine aggregate made of burner molten slag aggregate treated with the expansion inhibitor of the present invention. However, by performing the mortar expansion test, there is an advantage that a heating step is unnecessary. Moreover, by the action of calcium acetate, a protective film made of an insoluble basic aluminum acetate film is formed on the surface of the metal aluminum in the burner molten slag aggregate, preventing hydrogen generation due to reaction with the alkali component in the cement, The expansion rate of the mortar could be reliably suppressed to an appropriate value of 2% or less, and the strength reduction of the mortar could be suppressed.

Example 23
Among the above-mentioned four embodiments for producing mortar using the expansion inhibitor for concrete aggregate of the present invention, the method is carried out by the third method.

  That is, after adding and dispersing a pulverized particulate molten slag aggregate at a predetermined ratio in an aqueous solution of calcium acetate, which is an expansion inhibitor for concrete aggregate of the present invention, it is allowed to stand at room temperature for a required time. Then, an expansion-suppressed concrete aggregate-dispersed aqueous solution is produced. Next, the expansion-suppressed concrete aggregate dispersion aqueous solution, cement, and AE water reducing agent were blended at a predetermined ratio and kneaded into a paste to produce a mortar.

  First, the same waste incineration ash burner molten slag 1350 g as used in Example 21 was prepared.

  Next, 540 g of water was put into a stainless steel square bat of about 5 liters, and then 6.75 g of calcium acetate, which is an expansion inhibitor for mortar aggregates of the present invention, was dissolved therein to obtain an aqueous calcium acetate solution (pH: 7 .3) was produced.

  After that, 1350 g of the burner molten slag was put into a stainless steel square bat and dispersed in the calcium acetate aqueous solution, and then left at room temperature (about 10 ° C. during the test) for about 2 hours to suppress expansion-suppressed concrete bone. A material-dispersed aqueous solution was prepared.

  In addition, it was 0.500 weight% when the addition amount (weight%) of the expansion inhibitor with respect to slag was calculated from said weight density | concentration.

  Next, 1896.75 g of this expansion-suppressed concrete aggregate dispersion aqueous solution, 1200 g of Portland cement, and 60 g of an AE water reducing agent (those diluted to 1/10 of the stock solution) were mixed and kneaded into a paste to prepare a mortar. .

Example 24
In the same manner as in Example 23 above, mortar is produced using the concrete aggregate expansion inhibitor of the present invention. In 540 g of water, calcium acetate which is the expansion inhibitor for mortar aggregate of the present invention is used. 5 g was dissolved to prepare an aqueous calcium acetate solution (pH: 7.4). From this weight concentration, the addition amount (% by weight) of the expansion inhibitor relative to the slag was calculated to be 1.000% by weight.

Comparative Example 6
For comparison, a mortar is produced by using the concrete aggregate expansion inhibitor in the same manner as in Example 23. As a concrete aggregate expansion inhibitor, a conventional nitrite-based expansion inhibitor 6. A nitrite-based expansion inhibitor aqueous solution (pH: 7.0) in which 75 g was dissolved in 540 g of water was used. From this weight concentration, the addition amount (% by weight) of the expansion inhibitor relative to the slag was calculated to be 0.500% by weight.

Subsequently, the mortar expansion test was carried out on the mortar specimens obtained in Examples 23 and 24 and Comparative Example 6 in the same manner as in Example 1 above. The measurement results of the expansion rate of the obtained mortar test piece, the type of expansion inhibitor, the amount of expansion inhibitor dissolved (g), pH, and the amount of expansion inhibitor added to the slag aggregate (% by weight) are as follows: Table 5 below summarizes the results.

  As is clear from the results of Table 5 above, according to Examples 23 and 24 of the present invention, a particulate burner molten slag pulverized into an aqueous solution of calcium acetate, which is an expansion inhibitor for concrete aggregates of the present invention. After the aggregate is charged and dispersed at a predetermined ratio, it is allowed to stand at room temperature for a required time to produce an expansion-suppressed concrete aggregate-dispersed aqueous solution. In the state of the aggregate-dispersed aqueous solution, a protective film made of an insoluble basic aluminum acetate film is formed on the surface of metallic aluminum in the molten slag aggregate by the action of calcium acetate. Then, the expansion-suppressed concrete aggregate-dispersed aqueous solution, the cement, and the AE water reducing agent are blended at a predetermined ratio, kneaded into a paste, and manufactured by mortar, thereby reacting with an alkali component in the cement. Hydrogen generation was prevented, and the expansion rate of the mortar could be surely suppressed to an appropriate value of 2% or less, and a decrease in strength of the mortar could be suppressed.

  On the other hand, according to Comparative Example 6 using a conventional nitrous acid type expansion inhibitor, the expansion rate of the mortar exceeded 2%, and it was not possible to suppress a decrease in strength of the mortar.

Example 25
Of the above-mentioned four embodiments for producing mortar using the expansion inhibitor for concrete aggregates of the present invention, the fourth method is used.

  That is, in the aqueous solution of the expansion inhibitor for concrete aggregate of the present invention, the pulverized particulate molten slag aggregate is added and dispersed at a predetermined ratio to obtain an expansion-suppressed concrete aggregate dispersion aqueous solution, and then immediately. Cement and an AE water reducing agent were blended in a predetermined ratio in this expansion-suppressed concrete aggregate-dispersed aqueous solution and kneaded into a paste to produce a mortar.

 First, the same waste incineration ash burner molten slag 1350 g as used in Example 21 was prepared.

 Next, 540 g of water was put into a stainless steel square bat of about 5 liters, and then 6.75 g of calcium acetate, which is an expansion inhibitor for mortar aggregates of the present invention, was dissolved therein to obtain an aqueous calcium acetate solution (pH: 7 .3) was produced. From this weight concentration, the addition amount (% by weight) of the expansion inhibitor relative to the slag was calculated to be 0.500% by weight.

 Thereafter, 1350 g of the burner molten slag was put into a stainless steel square bat and dispersed in the calcium acetate aqueous solution to obtain an expansion-suppressed concrete aggregate-dispersed aqueous solution. To 75 g, 1200 g of Portland cement and 60 g of AE water reducing agent (those diluted to 1/10 of the stock solution) were blended and kneaded into a paste to prepare a mortar.

Example 26
In the same manner as in Example 25 above, mortar is produced using the concrete aggregate expansion inhibitor of the present invention. In 540 g of water, calcium acetate which is the expansion inhibitor for mortar aggregate of the present invention is used. 5 g was dissolved to prepare an aqueous calcium acetate solution (pH: 7.4). From this weight concentration, the addition amount (% by weight) of the expansion inhibitor relative to the slag was calculated to be 1.000% by weight.

Example 27
In the same manner as in Example 25 above, mortar is produced using the concrete aggregate expansion inhibitor of the present invention, but 540 g of water is added, and then this is added with the expansion inhibitor for mortar aggregate of the present invention. A CMA (calcium / magnesium / acetate) 6.75 g was dissolved to prepare a CMA aqueous solution (pH: 8.0). From this weight concentration, the addition amount (% by weight) of the expansion inhibitor relative to the slag was calculated to be 0.500% by weight.

Example 28
In the same manner as in Example 25 above, mortar is produced using the concrete aggregate expansion inhibitor of the present invention. To 540 g of water, CMA (calcium. 13.5 g of magnesium acetate) was dissolved to prepare a CMA aqueous solution (pH: 8.1). From this weight concentration, the addition amount (% by weight) of the expansion inhibitor relative to the slag was calculated to be 1.000% by weight.

Comparative Example 7
For comparison, mortar was produced by the same method as in Example 25, but 540 g of water (pH: 7.0) was used without using a concrete aggregate expansion inhibitor.

Comparative Example 8
For comparison, mortar is produced by the same method as in Example 25 above, but 540 g of water is added, and then 6.75 g of a nitrite-based agent which is a conventional expansion inhibitor for concrete aggregate is added thereto. It melt | dissolved and the nitrite type chemical | medical agent aqueous solution (pH: 7.0) was produced. From this weight concentration, the addition amount (% by weight) of the expansion inhibitor relative to the slag was calculated to be 0.500% by weight.

Subsequently, the mortar expansion test was carried out on the mortar specimens obtained in Examples 25 to 28 and Comparative Examples 7 and 8 in the same manner as in Example 1 above. The measurement results of the expansion rate of the obtained mortar test piece, the type of expansion inhibitor, the amount of expansion inhibitor dissolved (g), pH, and the amount of expansion inhibitor added to the slag aggregate (% by weight) are as follows: Table 6 shows the results.

  As is clear from the results in Table 6 above, according to Examples 25 to 28 of the present invention, the pulverized particulate molten slag aggregate is added to the aqueous solution of the concrete aggregate expansion inhibitor of the present invention in a predetermined manner. The mixture is added and dispersed at a ratio to obtain an expansion-suppressed concrete aggregate-dispersed aqueous solution. Immediately thereafter, cement and AE water reducing agent are blended into the expansion-suppressed concrete aggregate-dispersed aqueous solution at a predetermined ratio to obtain a paste form. The mortar is kneaded into a mortar, so there is an advantage that a heating process is unnecessary, and in the state of a concrete aggregate dispersed aqueous solution, the action of calcium acetate causes the surface of the metal aluminum in the molten slag aggregate to A protective film made of an insoluble basic aluminum acetate film is formed. And generation | occurrence | production of hydrogen by reaction with the alkali component in a cement was prevented, the expansion rate of the mortar could be reliably suppressed to an appropriate value of 2% or less, and the strength reduction of the mortar could be suppressed.

  On the other hand, according to Comparative Example 7 in which no expansion inhibitor was used and Comparative Example 8 in which a conventional nitrite-based expansion inhibitor was used, in each case, the expansion rate of mortar exceeded 2%. Thus, a decrease in strength of the mortar could not be suppressed.

  In the above examples, the mortar was produced using the concrete aggregate expansion inhibitor according to the present invention, and the mortar expansion test was carried out. Similarly, when concrete is produced by mixing concrete aggregates and the concrete expansion test is performed, hydrogen generation due to reaction with alkali components in the cement is similarly prevented, and the expansion of the concrete is less than 2%. While being able to suppress to a value reliably, the strength fall of concrete can be suppressed.

Claims (4)

  An expansion inhibitor for concrete aggregates, which is an expansion inhibitor used for a concrete aggregate made of a metal aluminum-containing molten slag aggregate, and contains an alkali metal and / or alkaline earth metal acetate.   The expansion inhibitor for concrete aggregates according to claim 1, wherein the alkali metal is potassium or sodium.   The expansion inhibitor for concrete aggregates according to claim 1, wherein the alkaline earth metal is calcium and / or magnesium.   Metallic aluminum-containing molten slag aggregate is treated with an expansion inhibitor for concrete aggregates according to any one of claims 1 to 3 to produce an alkali metal and / or alkaline earth metal acetate. An anti-expansion concrete aggregate characterized in that a protective coating made of an insoluble basic aluminum acetate coating is formed on the surface of metallic aluminum in the slag aggregate by action.