JP5173580B2 - Coal ash filler compounding design method - Google Patents

Description

  The present invention relates to a blending design method for a coal ash filler, and more particularly to a blending design method for a coal ash filler that can be used for cavity filling of a civil engineering structure, land reclamation, backfilling of a stagnant portion, and the like.

Fly ash is generated as a by-product when coal is burned at a thermal power plant as a combustion raw material, and is collected in large quantities by a dust collector in a boiler flue.
The effective use of this fly ash has been studied in many fields. For example, the Japan Society of Civil Engineers 2003 National Conference Research Discussion Group Research Materials 16 “Effective Utilization Technology of Coal Ash—Toward a Recycling Society” (Non-Patent Document 1) describes a reference example for multiple uses.

In particular, there is typically fly ash cement in which fly ash is mixed with cement, and effective use for fillers, backfilling materials, backfilling materials, etc. using a slurry containing a large amount of fly ash has also been proposed. .
In particular, when using materials that make effective use of fly ash as civil engineering and building materials such as fillers, backfill goods, and backfill materials in the civil engineering and construction fields, the flow value of coal ash slurry, the axis of the solidified material The compressive strength, bleeding rate and the like are required to be within a predetermined range.
These desired properties are adjusted by increasing or decreasing the blending amount of each material, and the fluidity is usually adjusted by the unit water amount blended.
However, when the amount of unit water to be blended is large, the time for maintaining the fluidity after slurry preparation becomes short, resulting in problems such as poor workability, and easy bleeding after solidification.

With regard to the slurry containing fly ash, many examples of research have been proposed for improving physical properties, and various additives have been proposed in addition to the adjustment based on the blending amount of each material.
For example, Japanese Patent Application Laid-Open No. 2003-267663 (Patent Document 1) proposes to contain a water-soluble cationic polymer compound in the ash slurry for stable fluidity improvement of the ash slurry. .

In addition, the characteristics of coal ash vary depending on the locality of the coal used as the raw material, and it is clear that the physical properties of the coal ash are affected by the components of the raw material coal.
Therefore, in order to determine the composition of civil engineering and building materials such as fillers using fly ash, it is necessary to obtain fly ash in advance, conduct a compounding test in advance, and prepare for actual on-site construction. It is the current situation that does not become, it is very complicated.
Furthermore, there are few cases where the fly ash used in the pre-mixing test and the fly ash carried into the construction site have the same physical properties, and the physical properties of the resulting coal ash filler slurry may vary depending on the physical properties of the fly ash used. In such a case, the quality of the coal ash filler slurry falls outside the desired quality control standard and may not be used.
In this way, when coal ash filler slurry is used as civil engineering / building materials, etc., especially when a large amount of coal ash is used, fly ash properties can be obtained. It becomes a factor and a big problem.

Usually, fly ash used for civil engineering such as fillers and building materials often uses fine powder obtained by classifying fly ash collected by a dust collector after burning coal in a boiler.
Therefore, after the fly ash generated at the coal-fired power plant is collected by the dust collector, a separate classification process is required to classify the fine pulverized portion from the fly ash raw powder, thereby effectively utilizing the fly ash raw powder. In addition, there is no economic advantage due to cost increase by adding a classification process.

  On the other hand, Japanese Patent No. 3993914 (Patent Document 2) discloses a method for determining the blending ratio of each material constituting a hardened body using a large amount of fine coal ash powder. Specifically, cement and coal are disclosed. A fine powder such as ash and water are kneaded to produce a kneaded product, and a flow test is performed on the kneaded product to obtain a water powder ratio indicating a predetermined flow value. An estimated value of the water powder ratio that maximizes the compressive strength is obtained by calculation, and an estimated value of the compression strength of the cured body is obtained from the estimated value of the water powder ratio by computation, and the estimated value of the compressive strength and the cured body By calculating the cement addition rate from the required compressive strength, a flow test is performed on the resulting kneaded product without performing a complicated test such as a soil compaction test as in the past, and a predetermined flow value is obtained. If the water / powder ratio shown is determined, compression of the cured product is performed by calculation. Degree can be determined blending ratios for water powder ratio and cement additive rate to maximize the blending ratio determining method of the material of the cured body is disclosed.

However, in the above method, the method for determining the blending ratio is complicated, and a blending test must be performed until a predetermined flow value is exhibited. There is nothing that can be used as a guide in such a case, and the current situation is that it depends on the experience of the person in charge of the formulation test.
Also, if the coal ash delivered to the construction site is different in physical properties from the pre-mixing test, the response at the construction site must be carried out from the test showing the predetermined flow value, that is, the indoor mixing test. In such a situation, considering the implementation work, it is complicated and not universal.
Japan Society of Civil Engineers 2003 National Conference Research Discussion Research Group-16 Materials “Effective Utilization Technology of Coal Ash—Toward a Recycling Society” (Non-patent Document 1) Japanese Patent Laid-Open No. 2003-267663 Japanese Patent No. 3999314

An object of the present invention is to solve the above problems and to effectively use ash such as coal ash as a civil engineering building material or the like, regardless of the type of coal ash, particularly fly ash, coal having a desired fluidity value. It aims at providing the compounding design method of the coal ash filler which can determine easily the compounding quantity of each material mix | blended with an ash filler slurry.
In particular, an object of the present invention is to provide a coal ash filler blending design method that can use raw coal ash powder without classifying the coal ash, and thus can effectively use a large amount of coal ash. To do.
Furthermore, it is possible to easily modify the coal ash filler composition on site due to changes in the physical properties of the coal ash delivered to the construction site, and the use of a wide range of coal ash is possible. It aims at providing the compounding design method.

  The present invention uses the correlation equation between the fluidity value of coal ash slurry containing fly ash and water and the unit water amount of the coal ash cement mixed slurry mixed with fly ash, water and cement, and the coal actually used Regardless of the type of fly ash that is ash, blending of coal ash filler slurry with the desired fluidity by measuring the fluidity value of fly ash and water containing coal ash slurry containing water The present invention has been achieved by finding that the determination of the amount can be simplified.

  That is, the coal ash filler blending design method of the present invention comprises a fluidity value 1 indicating the fluidity of coal ash slurry 1 containing fly ash and water at a predetermined mixing ratio, cement, fly ash and water. A coal containing a cement, fly ash, and water is obtained based on a correlation formula with the unit water amount W3 of the coal ash cement mixed slurry 2 when the coal ash cement mixed slurry 2 containing the mixture shows a predetermined fluidity. It is the compounding design method of the coal ash filler characterized by determining the compounding quantity in an ash filler slurry.

Specifically, the method for blending and designing coal ash filler according to the present invention produces coal ash slurry 1 containing fly ash and water at a predetermined weight mixing ratio of 1: 0.4 to 0.6 , and A flow rate numerical value 1 measurement process for performing a flowability test on the slurry 1 to measure the flowability numerical value 1;
Generate coal ash cement mixed slurry 2 containing the cement fly ash and water, by changing the unit water W2 of water to be blended in the slurry 2 for respective slurry 2 obtained by performing the fluidity test A derivation step of correlation equation 1 for measuring fluidity value 2 and deriving correlation equation 1 relating to flow value 2 that is fluidity value 2 for each changed unit water amount W2;
Using correlation equation 1, eventually in association with the flow value 2 of the desired equal flow value 3 is a predetermined fluidity numeric 3 Coal Ash filler slurry, corresponding to the flow value 3 units A corresponding step of determining the water amount W3 as a unit water amount W2 corresponding to the corresponding flow value 2, and corresponding the unit water amount W3 to the fluidity value 1 ;
By changing the type of full fly ash, performs the step of measuring fluidity numerical 1, wherein the repeated step of deriving the correlation equation 1 flowable number 2, and the corresponding steps of said unit water W3 and liquidity numeric 1 A derivation step of correlation equation 2 for deriving correlation equation 2 relating to fluidity value 1 with respect to unit water amount W3 by the least square method using unit water amount W3 and fluidity value 1 that vary depending on the type of fly ash ;
In determining the blending amount of the coal ash filler slurry using the correlation equation 2 , a coal ash slurry 3 containing fly ash and water used for the coal ash filler slurry at the predetermined weight mixing ratio is generated and obtained. By measuring the fluidity value 4 measured by performing the fluidity test on the coal ash slurry 3 obtained, determining the density of the fly ash, and introducing the fluidity value 4 into the correlation equation 2 The unit water amount W4 blended in the coal ash filler slurry is determined, and the fly ash amount blended in the coal ash filler slurry is determined from the cement amount blended, the determined unit water amount W4, and the density of the fly ash. It is a compounding design method of a coal ash filler characterized by having a process .

Preferably , the coal ash filler blending design method of the present invention further derives a correlation equation 3 between the change amount of the unit water amount W2 with respect to the change amount of the fluidity value 2 of the coal ash cement mixed slurry 2. The fluidity value 5 is measured by performing the fluidity test on the coal ash filler slurry, and the difference (Δx) between the fluidity value 5 and the predetermined fluidity value 3 is calculated. The amount of increase / decrease in unit water amount (ΔW4) is calculated from the difference (Δx) in the calculated fluidity value, and blended so that a coal ash filler slurry having a predetermined fluidity value 3 is obtained. by ΔW4 increase and decrease resulting unit water W4, and determining the amount of coal ash filler, a mix design method of coal ash filler.

Here, in the present invention, “coal ash” means fly ash collected by a dust collector after burning coal in a boiler. In this case, it does not matter whether the particles have been classified by the classification process after being collected by the dust collector.
“Raw powder” means fly ash generated from a boiler and collected by a dust collector. Therefore, the fly ash is not classified by a classifier and the particle size is not adjusted.
“Coal ash slurry” means a slurry containing fly ash and water and no cement.
The “coal ash cement mixed slurry” means a slurry containing fly ash, cement and water.
“Coal ash filler slurry” means a slurry containing fly ash, cement and water that is actually used on site as a coal ash filler.

According to the coal ash filler blending design method of the present invention, it is possible to easily determine the blending of each material to be blended into the coal ash filler slurry having a desired fluidity value regardless of the type of fly ash. It becomes.
In other words, by simply measuring the fluidity values of the slurry containing coal ash fly ash and water, the material blending amount of the desired coal ash filler slurry can be easily determined even during material delivery at the construction site. Can do.
In addition, it is possible to easily modify the blending of coal ash filler due to changes in the physical properties of the coal ash delivered to the construction site, and a wide range of coal ash can be used.
Therefore, it is easy to obtain a coal ash filler slurry having a desired fluidity value.
In particular, in the present invention, since the fly ash raw powder can be used without performing the conventional treatment such as classification of fly ash, a large amount of coal ash can be effectively used.
In addition, by confirming the state after mixing fly ash and water, it is possible to easily determine whether the fly ash raw powder can be used as a coal ash filler compounding material. Confirmation can be easily performed.

The present invention will be described with reference to the following preferred embodiments.
The method for blending and designing coal ash filler according to the present invention includes a fluidity value 1 indicating the fluidity of coal ash slurry 1 containing fly ash and water at a predetermined weight mixing ratio, cement, fly ash, and water. When the coal ash cement mixed slurry 2 shows a predetermined fluidity, a correlation formula with the unit water amount W3 of the coal ash cement mixed slurry 2 is obtained, and based on the correlation formula, each material to be blended in the coal ash filler slurry The amount is determined.

Specifically, a coal ash slurry 1 containing fly ash and water at a predetermined weight mixing ratio is generated, and a fluidity test is performed on the slurry 1 to measure a fluidity value 1. Process,
A coal ash cement mixed slurry 2 containing cement, fly ash, and water is generated, the unit water amount W2 of water mixed in the slurry 2 is changed, and a fluidity test is performed on each of the obtained slurries 2 to obtain a fluidity value. A derivation step of correlation equation 1 for measuring 2 and deriving correlation equation 1 for fluidity value 2 for each changed unit water amount W2;
Using the correlation equation 1, the unit water amount W3 is determined from the predetermined fluidity value 3 of the desired coal ash filler slurry, and the unit water amount W3 and the fluidity value 1 are made to correspond to each other. The corresponding process with sex value 1;
By changing the type of fly ash, the measurement step of the fluidity value 1, the derivation step of the correlation equation 1, and the corresponding step of the unit water amount W3 and the fluidity value 1 are repeated, and the type of fly ash A correlation equation 2 derivation step for deriving a correlation equation 2 relating to the fluidity value 1 with respect to the unit water amount W3 from a plurality of correspondences between the unit water amount W3 and the fluidity value 1 that change according to
This is a coal ash filler blending design method in which the amount of each material blended in a coal ash filler slurry having a predetermined fluidity value 3 is determined using the correlation equation 2.

Details will be described below.
First, an example of a method for deriving correlation equation 2 is shown as a flowchart in FIG.
In the measurement step of the fluidity value 1, the coal ash slurry 1 containing fly ash and water at a predetermined weight mixing ratio is generated, and the fluidity test is performed on the slurry 1 to measure the fluidity value 1. Then, a coal ash slurry 1 containing fly ash and water at a predetermined weight ratio is prepared.
The fly ash can be applied to either fly ash raw powder, fly ash differential or coarse powder after the fly ash raw powder is classified, but the fly ash can be reused in large quantities at low cost. The fly ash raw powder is preferably applied because it can be used.
The coal ash slurry 1 may be a slurry containing not only a fly ash and water slurry, but also a fly ash and water, and additives that are usually added to fillers and the like.
The fly ash and water in the coal ash slurry 1 are mixed at a constant weight ratio, but usually fly ash: water is a fixed ratio selected from a weight ratio of 1: 0.4 to 0.6. Mix in a weight ratio, for example 1: 0.5.

  When fly ash and water are blended at such a blending ratio, when the state is a frustrated state and the kneading vessel is not tilted and does not flow out as a slurry, that is, when it does not become a coal ash slurry, the fly ash Cannot be used as coal ash in the present invention.

Next, a fluidity test is performed on the coal ash slurry 1 to measure a fluidity value of 1.
As such a fluidity test, a known fluidity test can be applied, and examples thereof include a flow test and a funnel test.
For example, the above coal ash slurry 1 is subjected to a flow test according to JHS-313 ((former) Japan Highway Public Corporation test method) using a cylindrical flow cone of Φ80 × 80 mm, and a flow value of 1 (mm) is measured.

Next, in the step of deriving the correlation equation 1, a coal ash cement mixed slurry 2 containing cement, fly ash, and water is prepared.
However, the fly ash to be used is the same as the fly ash used when the coal ash slurry 1 is prepared.
For example, the blending amount in the coal ash cement mixed slurry 2 is determined by setting the unit cement amount to be kneaded per unit volume (1 m ³ ), appropriately setting the unit water amount W2 to be kneaded, and the balance as the fly ash amount. To do.
The blending amounts of cement, water and fly ash determined in this way are weighed and kneaded sufficiently to prepare a coal ash cement mixed slurry 2. At this time, a plurality of coal ash cement mixed slurries 2 blended by appropriately changing the unit water amount W2 to be kneaded are prepared.
Each of the coal ash cement mixed slurries 2 is not limited to a slurry composed of fly ash, water, and cement, but may be a slurry containing fly ash, water, cement, and additives that are usually added to fillers. is there.

About each obtained coal ash cement mixing slurry 2, a fluidity | liquidity test is each performed and the fluidity | liquidity numerical value 2 is measured.
As the fluidity test, a known fluidity test can be applied. For example, a flow test or a funnel test is exemplified, but the flow applied when measuring the fluidity value 1 of the coal ash slurry 1 is exemplified. The same fluidity test as the test is applied.
Therefore, when the flow value 1 (mm) is measured by performing a flow test according to JHS-313, using a φ80 × 80 mm cylindrical flow cone for the coal ash slurry 1 in the measurement step of the fluidity value 1. The following fluidity test applied to each coal ash cement mixed slurry 2 is also a flow test according to JHS-313 using a cylindrical flow cone of Φ80 × 80 mm. A value of 2 must be measured.
Moreover, as described above, by measuring the flow value 2 by applying the above fluidity test for each of the plurality of coal ash cement mixed slurries prepared by appropriately changing the unit water amount W2 in the coal ash cement mixed slurry, Correlation equation 1 for flow value 2 with respect to changing unit water amount W2 when the same fly ash is used is derived.

Using the derived correlation equation 1, a flow value 3 that is a predetermined fluidity value 3 of the finally desired coal ash filler slurry is made to correspond to the flow value 2 of the same value, and the flow value 3 The corresponding unit water amount W3 is determined as the unit water amount W2 corresponding to the corresponding flow value 2, and the unit water amount W3 is associated with the fluidity value 1.
The type of fly ash used in the coal ash slurry 1 and the coal ash cement mixed slurry 2 used when the unit water amount W3 and the fluidity value 1 are matched is the same as described above. is there.
As a result, a correspondence relationship between the unit water amount W3 and the fluidity value 1 for a certain type of fly ash is obtained.

  By changing the type of the fly ash, the measurement step of the fluidity value 1, the derivation step of the correlation equation 1 of the fluidity value 2, and the corresponding step of the unit water amount W3 and the fluidity value 1 are repeated. Then, a plurality of correspondence relationships between the unit water amount W3 that varies depending on the type of fly ash and the fluidity value 1 are obtained, and a correlation equation 2 between the unit water amount W3 and the fluidity value 1 is derived from the obtained correspondence relationships. . At this time, the correlation equation 2 is derived by a known method such as a least square method using the corresponding relationship values.

  In this way, the correlation equation 2 that is a relational expression between the unit water amount W3 and the flow value 1 that is the fluidity value 1 of the coal ash slurry 1 containing fly ash and water is obtained in advance and the correlation expression 2 is used. Thus, regardless of the type of fly ash to be used, the coal ash slurry 3 containing fly ash and water is prepared at the site, and the fluidity test of the coal ash slurry 3 prepared at the site is performed, and thus desired. It becomes possible to determine the blending amount of the coal ash filler slurry having a fluidity value of 3.

FIG. 2 is a flowchart showing an example of a method for determining the blending amount of the coal ash filler slurry using the correlation equation 2.
Specifically, first, fly ash used for the coal ash filler slurry used on site and water are blended at a constant weight ratio to prepare the coal ash slurry 3.
At that time, the constant blending weight ratio between the fly ash of the coal ash slurry 3 and the water at that time is the fly ash applied in the measurement step of the fluidity value 1 when the correlation equation 2 to be used is derived. It mix | blends by the same weight ratio as the mixing | blending weight ratio of the fly ash of the coal ash slurry 1 containing water, and water. Next, the fluidity value 1 of the coal ash slurry 1 containing fly ash and water applied in the measurement step of the fluidity value 1 when the correlation equation 2 to be used is derived from the fluidity value 4 of the coal ash slurry 3. Apply a fluidity test similar to the fluidity test applied when measuring.

Further, the density of the fly ash is measured. The measuring method is not particularly limited, and any method can be used. For example, after putting the coal ash slurry 3 into a container with a clear volume and discharging the air of the slurry 3 by vibration or the like, the mass is measured, and the mass is divided by the volume to obtain the density (M1) of the coal ash slurry 3 And the density MF of the fly ash used can be determined as follows.
MF = (weight of blended water) / ((weight of measured coal ash slurry) / M1- (weight of blended fly ash)

By introducing the fluidity value 4 thus measured as the fluidity value of the correlation equation 2, the unit water amount W4 to be blended in the coal ash filler slurry is determined. The unit water amount W4 is a unit water amount W4 to be blended on-site with the coal ash filler slurry having a desired fluidity value of 3.
Therefore, when the amount of cement blended in the coal ash filler slurry is constant, the fly ash blended in the coal ash filler slurry is determined from the unit water amount W4 determined from the correlation equation 2 and the density of the fly ash. The amount can be determined, and the blending design of the coal ash filler slurry on site can be determined by a simple method.

  In addition, as described above, the unit water amount to be blended in the coal ash filler slurry having a desired fluidity value can be determined, but since the correlation equation 2 is an equation derived by the least square method or the like, Even if the blending amount of the coal ash filler slurry is determined using the correlation equation 2 as described above, depending on the type of fly ash actually used in the field, the fluidity value of the obtained coal ash filler slurry is desired. In some cases, the unit water amount W4 can be corrected by the following method. FIG. 3 is a flowchart showing an example of a method for correcting the unit water amount 4 to be blended.

First, correlation 3 of the change amount of the unit water amount W2 with respect to the change amount of the fluidity value 2 of the coal ash cement mixed slurry 2 is derived.
The correlation equation 3 is a relational expression of the change amount of the unit water amount W2 with respect to the change amount of the fluidity value 2 regarding the coal ash cement mixed slurry 2 obtained when the correlation equation 1 is derived.
As described above, for the plurality of coal ash cement mixed slurries prepared by changing the unit water amount W2, the change in the fluidity numerical value 2 for each of the plurality of coal ash cement mixed slurries 2 prepared by changing the unit water amount W2 is performed. Correlation equation 3 with the amount of change of the unit water amount W2 (ΔW) with respect to the amount (Δx) is derived.
At this time, the change amount (ΔW) of the unit water amount W2 with respect to the change amount (Δx) of the fluidity numerical value 2 is the slope coefficient of the relational expression of the unit water amount W2 with respect to the fluidity numerical value 2 for each coal ash cement mixed slurry 2. Correspondingly, since the slope coefficient of each relational expression is substantially constant regardless of the type of fly ash, the correlation expression of the change amount (ΔW) of the unit water amount W2 with respect to the change amount (Δx) of the fluidity value 2 3 can be derived.
At this time, it is preferable that the average value of the slope coefficient of the relational expression of each coal ash cement mixed slurry 2 is the slope of the correlation expression 3.

Actually, the same fluidity test as described above was performed on the coal ash filler slurry used in the field, and the fluidity value 5 was measured. The fluidity value 5 and the desired fluidity value 3 were slightly different. If it has calculates a difference ([Delta] x _5-3) with its fluidity numeric 5 and fluidity numerical 3, the difference ([Delta] x _5-3) of the calculated flow numerical to the correlation expression 3 By applying, the increase / decrease amount (ΔW ₄ ) of the unit water amount W4 can be calculated.
Thus, by correcting the unit water amount W4 so that a coal ash filler slurry having a predetermined fluidity value 3 is obtained, the blending of the coal ash filler having the desired fluidity value 3 is accurately determined. It becomes possible.
Therefore, when the cement amount to be blended is constant, the unit water W4 ± [Delta] W ₄ determined to reflect the correction, to determine the fly ash amount of blending (density measurements), the coal ash filler material This makes it possible to design a precise formulation.

  Regarding the correction of the unit water amount, actually, a coal ash filler slurry blended at a blending ratio of fly ash, cement and water determined from the above correlation equation 2 is prepared and kneaded, and is different from the target flow value 3. It can be used as a correction method when the flow value is reached, or as a calculation method when obtaining the unit water amount when the flow value of the coal ash slurry 3 is not the target flow value 3 from the beginning.

  Thus, the method of the present invention is a simple blending and designing method for a coal ash filler that can be used regardless of the type of fly ash.

About 20 types of fly ash raw powders A to R shown in Table 1 below, each fly ash raw powder and water (tap water) have a constant weight ratio of 1: 0.5 (100 g: 50 g). The fly ash raw powder and water were weighed and blended, and kneaded sufficiently to prepare each coal ash slurry 1.
Next, for each obtained coal ash slurry 1, a flow test was performed according to JHS-313 using a Φ80 × 80 mm cylindrical flow cone, and each flow value 1 (mm) was measured. The results are shown in Table 1. .
Moreover, the density of each coal ash slurry 1 was measured. In this method, the slurry 1 was put in a container with a clear volume, the air of the slurry 1 was discharged by vibration or the like, and the mass was measured. The mass divided by the volume is the density of the coal ash slurry 1, which is M1, and the fly ash density MF was determined by the following equation.
MF = 100 / ((100 + 50) / M1-50)
For example, when the slurry density is 1.5 g / cm ³ ,
MF = 100 / (150 / 1.5-50) = 100 / (100-50) = 100/50 = 2.0 (t / cm <3>)
It became.
The density of each fly ash A to R was determined as described above, and the results are also shown in Table 1.

Next, each coal ash cement mixed slurry is prepared. As materials to be blended, various types of fly ash raw powders A to R in Table 1 above, blast furnace cement type B (density 3.05 kg / m ³ ) and tap water were used.
First, using the fly ash raw powder A in Table 1 above, the blast furnace cement to be blended is set to 100 kg / m ³ , the unit water amount W2 (kg / m ³ ) to be blended is appropriately set, and the fly ash raw powder A A coal ash cement mixed slurry 2 of blast furnace cement and water was prepared.

That is, for example, if the blast furnace cement B type is 100 kg / m ³ and the unit water amount W2 (water density is 1.0 g / cm ³ ) is 500 kg, the density of the fly ash raw powder A used is 1 to MF2.12 t / m ³ , the amount of fly ash to be blended in the coal ash cement mixed slurry was determined as follows.
Fly ash amount (kg / m3)
= (1000-100 / 3.05-500 / 1.0) x 2.12
= 990kg

Accordingly, 100 kg of blast furnace cement B, 500 kg of water and 990 kg of fly ash raw powder A are blended and kneaded to obtain a coal ash cement mixed slurry 2, and a flow value 2 (mm) of the obtained coal ash cement mixed slurry 2 Was measured by the above flow test according to JHS = 313.
For the same fly ash raw powder A, the unit water amount W2 to be blended is changed, and a flow value 2 is obtained for each of the obtained coal ash cement mixed slurries 2 to obtain coal ash cement relating to the fly ash raw powder A. FIG. 4 shows the relationship between the flow rate 2 and the unit water amount W2 of the mixed slurry 2 that changes.
As shown in FIG. 4, the correlation formula 1 regarding the flow value 2 with respect to the changing unit water amount W2 regarding the fly ash raw powder A was derived.

Moreover, the fly ash raw powders B to R are respectively used as fly ash raw powders, and for each fly ash, a coal ash cement mixed slurry 2 is prepared in the same manner as described above, and the unit water amount W2 blended in the same manner as described above is changed. Then, the same flow test as described above is performed for each of the coal ash cement mixed slurries 2, the flow value 2 is measured, and the flow with respect to the unit water amount W2 of the coal ash cement mixed slurry 2 regarding each fly ash raw powder B to R Correlation equation 1 for value 2 was derived respectively.
The straight lines corresponding to the derived correlation equations 1 are shown in FIG.

Next, a predetermined flow value 3 as a target of the coal ash filler slurry used for the desired coal ash filler was determined, and a unit water amount W3 corresponding to the flow value 3 was determined using the correlation equation 1.
That is, by using the derived correlation equation 1, a flow value 3 that is a predetermined fluidity value 3 of the finally desired coal ash filler slurry is made to correspond to the flow value 2 of the same value, and the flow value The unit water amount W3 corresponding to 3 was determined as the unit water amount W2 corresponding to the corresponding flow value 2.
Specifically, it was determined as a unit water amount W3 (horizontal axis) in each correlation equation 1 having a flow value corresponding to the flow value 3 of the flow value (vertical axis) in FIG.

The relationship between the plurality of unit water amounts W3 of each coal ash cement mixed slurry and the plurality of flow values 1 measured from the coal ash slurry 1 of each of the fly ash raw powder and water thus determined. Is plotted for each type of fly ash with the flow value 1 of the coal ash slurry on the horizontal axis and the unit water amount W3 on the vertical axis, and the correlation equation 2 between the unit water amount W3 and the flow value 1 was obtained.
At this time, the correlation equation 2 is derived from a plurality of corresponding values (a plurality of plotted corresponding values) between the unit water amount W3 and the flow value 1 for each fly ash type by a known method such as a least square method ( FIG. 5).
In addition, when making the said unit water amount W3 and the said fluidity numerical value 1 correspond as mentioned above, the kind of fly ash used for the coal ash slurry 1 and the coal ash cement mixed slurry 2 was made the same. .

For example, when the flow value 3 of the target coal ash filler slurry is 200 mm, the coal ash cement mixed slurry 2 (using fly ash raw powder A) when the flow value is 200 mm from the correlation equation 1 in FIG. The unit water amount W2 corresponds to the unit water amount W3, the flow value 1 (Table 1) measured from the coal ash slurry 1 of fly ash raw powder A and water and the unit water amount W2 Corresponding values obtained by associating the relationship with the unit water amount W3 were plotted (FIG. 5).
Next, similarly, for the fly ash raw powders B to R, the unit water amount W2 when the flow value 3 is 200 mm is obtained from each correlation equation 1 in FIG. Corresponding values obtained by associating the relationship between each flow value 1 (Table 1) measured from each coal ash slurry 1 of fly ash raw powders B to R and water with the unit water amount W3 were plotted. FIG. 5 and Table 2 show the corresponding relationship.
However, the unit water amount W3 in Table 2 is obtained from each correlation equation 1 (FIG. 4) when the flow value of the coal ash filler slurry is 200 mm.

Correlation equation 2 was derived by the least square method using each of these correlation correspondence values.
From FIG. 5, the relationship between the unit water amount W3 and the flow value 1 was expressed as the following correlation equation 2.
W3 = −0.46 · FL ₁ (flow value 1) +600.

  Examples 1-3 of the blending of coal ash filler slurry for coal ash filler used in the field (desired flow value 3 is 200 mm) are shown below using the above correlation equation 2.

Example 1
(Materials used)
・ Tap water / Fly ash raw powder X (Density: 2.05 t / m ³ )
・ Blast furnace cement type B (density 3.05 t / m ³ )

The fly ash raw powder X and tap water are blended at a weight ratio of 1: 0.5 (100 g: 50 g) to prepare a coal ash slurry 3, and a cylindrical flow cone of Φ80 × 80 mm is used. A flow test and density measurement according to 313 were performed to obtain a flow value of 380 (mm). Moreover, the density MF2.05 t / cm ³ of fly ash X was obtained from the density of the obtained coal ash slurry 3 by the above method.
In addition, as above-mentioned, the density of the fly ash X measured the density of the said coal ash slurry 3 first. The slurry 3 was put in a container with a clear volume, and the air of the slurry 3 was discharged by vibration or the like, and then the mass was measured. The mass divided by the volume is the density M1 of the coal ash slurry 3, and the fly ash density MF2.05 t / cm ³ was determined by the following equation.
MF = 100 / ((100 + 50) / M1-50)

By applying the obtained flow value of 380 mm to FL of the above correlation equation 2: W3 = −0.46 · FL + 600, W3 = −0.46 × 380 + 600 = 425 (kg / m ³ ), and unit water amount W3 was calculated to be 425 kg / m ³ .
Next, 100 kg / m of the above blast furnace cement B type blended per unit capacity (1 m ³ )
³ , the amount of fly ash to be blended is determined as follows, assuming that the blended water (density is 1.0 g / cm ³ ) is the unit water amount 425 kg / m ³ calculated above.
The amount of fly ash X to mix
= (1000-100 / 3.05-425 / 1.0) x 2.05
= 938kg / m ³

In this way, by determining the ratio of the amount of coal ash filler slurry, actually blast furnace cement type B 100 kg / ^{m 3,} tap water 425 g / ^{m 3,} the proportions of fly ash 938kg / ^{m 3,} these materials And coal ash filler slurry was obtained.
The flow value of the obtained coal ash filler slurry was 200 mm when the flow value was obtained by performing a flow test according to the above JHS-313 using a Φ80 × 80 mm cylindrical flow cone similar to the above. It was confirmed that a coal ash filler slurry having a desired flow value was obtained.

Example 2
(Materials used)
-Tap water-Fly ash raw powder Y (density: 1.98 t / m ³ )
・ Blast furnace cement type B (density 3.05 t / m ³ )

The fly ash raw powder Y and tap water are mixed at a weight ratio of 1: 0.5 (100 g: 50 g) to prepare a coal ash slurry 3, and a cylindrical flow cone of Φ80 × 80 mm is used. A flow test and density measurement according to 313 were performed, and a flow value of 440 (mm) was obtained. Further, from the density of the coal ash slurry 3 obtained, a fly ash Y density of 1.98 t / cm ³ was obtained in the same manner as in Example 1.
By applying the obtained flow value of 440 mm to the FL of the above correlation equation 2: W3 = −0.46 · FL + 600, the unit water amount W3 was calculated to be 398 kg / m ³ .
Next, the above-mentioned blast furnace cement B type blended per unit capacity (1 m ³ ) is 100 kg, and the blended water (density is 1.0 g / cm ³ ) is blended assuming that the above calculated unit water amount is 398 kg / m ^3. The fly ash amount is determined as follows.
Amount of fly ash to be blended
= (1000-100 / 3.05-398 / 1.0) x 1.98
= 1126 kg / m ³

Thus blended ratio determining coal ash filler slurry, actually blast furnace cement type B 100 kg / ^{m 3,} tap water 398kg / ^{m 3,} the proportions of fly ash 1126kg / ^{m 3,} by blending these materials Thus, a coal ash filler slurry was obtained.
The flow value of the obtained coal ash filler slurry was 200 mm when the flow value was obtained by performing a flow test according to the above JHS-313 using a Φ80 × 80 mm cylindrical flow cone similar to the above. It was confirmed that a coal ash filler slurry having a desired flow value was obtained.

Example 3
(Materials used)
・ Tap water / fly ash raw powder Z (density: 2.08 t / m ³ )
・ Blast furnace cement type B (density 3.05 t / m ³ )

The fly ash raw powder Z and tap water are blended in a weight ratio of 1: 0.5 to prepare a coal ash slurry 3, and a cylindrical flow cone of Φ80 × 80 mm is used, according to the above JHS-313. A flow test and density measurement were performed to obtain a flow value of 251 (mm). Further, from the density of the obtained coal ash slurry, fly ash Z density of 2.12 t / cm ³ was obtained in the same manner as in Example 1.
By applying the obtained flow value of 251 mm to the FL of the above correlation equation 2: W3 = −0.46 · FL + 600, it was calculated that the unit water amount W3 was 485 kg / m ³ .

Next, when the above-mentioned blast furnace cement B type blended per unit volume (1 m ³ ) is 100 kg, and the blended water (density is 1.0 g / cm ³ ), the above-calculated unit water amount 485 kg / m ³ is blended. The fly ash amount is determined as follows.
Amount of fly ash to be blended
= (1000-100 / 3.05-485 / 1.0) x 2.08
= 1003 kg / m ³

In this way, by determining the ratio of the amount of coal ash filler slurry, actually blast furnace cement type B 100 kg / ^{m 3,} tap water 485 kg / ^{m 3,} the proportions of fly ash 1003kg / ^{m 3,} these materials And coal ash filler slurry was obtained.
The flow value of the obtained coal ash filler slurry was 140 mm when the flow value was obtained by performing a flow test according to the above JHS-313 using a Φ80 × 80 mm cylindrical flow cone similar to the above. When compared with the desired flow value (200 mm), the difference was 60 mm, which was lower than the desired flow value of the coal ash filler slurry by the difference flow value.

  In this way, the blended cement, fly ash and water coal ash filler slurry is actually kneaded, and the flow value is measured by the above flow test. The flow value is slightly smaller than the target flow value (200 mm). If not, the unit water amount is corrected to obtain the target flow value.

Specifically, the relationship between the unit water amount W2 of the coal ash slurry shown in FIG. 4 and the flow value 2 of the slurry 2 is shown in FIG.
From FIG. 6, the relationship between the change amount (ΔW) of the unit water amount W2 (kg / m ³ ) and the flow value 2 (x (mm)) of each coal ash cement mixed slurry 2 is as follows. It can be seen that there is a certain correlation regardless of the type (regardless of the type of fly ash).
That is, from each relational expression shown in FIG. 6, the increase / decrease amount of the relationship of the unit water amount W2 with respect to the change amount (Δx) of the flow value 2 of the coal ash cement mixed slurry 2 corresponds to the slope coefficient of each relational expression. When the average value of the slope coefficients of the respective relational expressions was obtained from 6, it was 0.5.
Therefore, the relationship between the change amount (ΔW) of the unit water amount W2 (kg / m ³ ) of the coal ash cement mixed slurry 2 and the change amount (Δx) of the flow value 2 is, regardless of the type of the prepared coal ash slurry, This is shown by the following correlation equation 3.
ΔW = 0.5Δx ... correlation equation 3
ΔW: Unit water volume to be increased or decreased (kg / m ³ )
Δx: Flow value to be increased or decreased (mm)

  It is possible to determine the unit water amount (ΔW4) to be increased or decreased by introducing a value corresponding to the flow amount of the change amount of the difference to be corrected into ΔW = 0.5Δx that is the correlation equation 3. It becomes possible to obtain a coal ash filler having exactly the desired flow value (200 mm).

Therefore, as described above, the difference between the desired flow value (200 mm) and the flow value of the actual coal ash filler slurry is 60 mm, and the flow value of the coal ash filler slurry is increased by 60 mm, which is the difference flow. If desired, the unit water amount ΔW30 kg / m ³ to be increased is calculated by applying the difference value of 60 mm to Δx in the correlation equation 3.

Next, assuming that the above-mentioned blast furnace cement B type blended per unit volume (1 m ³ ) is 100 kg and the water to be blended is 515 kg / m ³ added with the unit water amount calculated by the above correction, the amount of fly ash blended is as follows: It is determined as follows.
Amount of fly ash to be blended
= (1000-100 / 3.05-515 / 1.0) x 2.08
= 940 kg / m ³

In this way, the blending ratio of the coal ash filler slurry is determined, and these materials are actually blended at a blending ratio of blast furnace cement B type 100 kg / m ³ , tap water 515 kg / m ³ and fly ash 940 kg / m ^3. Thus, a coal ash filler slurry was obtained.
The flow value of the obtained coal ash filler slurry was 200 mm when the flow value was obtained by performing a flow test according to the above JHS-313 using a Φ80 × 80 mm cylindrical flow cone similar to the above. It was confirmed that a coal ash filler slurry having a desired flow value was obtained.

  The blending design method for coal ash filler of the present invention is a simple blending design method on site for coal ash filler slurry that can be used especially for civil engineering structure cavity filling, landfilling, and backfilling of stagnant water. Can be applied.

It is a flowchart which shows an example of the method until deriving correlation formula 2. It is a flowchart which shows an example of the method of determining the compounding quantity of the coal ash filler slurry using the correlation formula 2. It shows with a flowchart which shows an example of the method of correct | amending the unit water quantity 4 mix | blended with a coal ash filler slurry. Diagram showing correlation 1 showing the relationship of flow value 2 of slurry 2 to unit water amount W2 (kg / m ³ ) of coal ash cement mixed slurry 2 (each coal ash cement prepared by changing the type of fly ash Correlation formula 1 of the mixed slurry is displayed). Unit water amount W3 of coal ash cement mixed slurry 2 corresponding to a predetermined flow value 3 (the type of fly ash is the same as that used when measuring flow value 1) with respect to the flow value 1 of fly ash and water coal ash slurry FIG. FIG. 5 is a diagram illustrating the relationship between the unit water amount W2 of the coal ash cement mixed slurry shown in FIG. 4 and the flow value 2 of the slurry 2 as the relationship of the unit water amount W2 to the flow value 2;

Claims (2)

A coal ash slurry 1 containing fly ash and water at a predetermined weight mixing ratio of 1: 0.4 to 0.6 is generated, and a fluidity test is performed on the slurry 1 to measure a fluidity value of 1. A measurement process of a sex value of 1,
Generate coal ash cement mixed slurry 2 containing the cement fly ash and water, by changing the unit water W2 of water to be blended in the slurry 2 for respective slurry 2 obtained by performing the fluidity test A derivation step of correlation equation 1 for measuring fluidity value 2 and deriving correlation equation 1 relating to flow value 2 that is fluidity value 2 for each changed unit water amount W2;
Using correlation equation 1, eventually in association with the flow value 2 of the desired equal flow value 3 is a predetermined fluidity numeric 3 Coal Ash filler slurry, corresponding to the flow value 3 units A corresponding step of determining the water amount W3 as a unit water amount W2 corresponding to the corresponding flow value 2, and corresponding the unit water amount W3 to the fluidity value 1 ;
By changing the type of full fly ash, performs the step of measuring fluidity numerical 1, wherein the repeated step of deriving the correlation equation 1 flowable number 2, and the corresponding steps of said unit water W3 and liquidity numeric 1 A derivation step of correlation equation 2 for deriving correlation equation 2 relating to fluidity value 1 with respect to unit water amount W3 by the least square method using unit water amount W3 and fluidity value 1 that vary depending on the type of fly ash ;
In determining the blending amount of the coal ash filler slurry using the correlation equation 2 , a coal ash slurry 3 containing fly ash and water used for the coal ash filler slurry at the predetermined weight mixing ratio is generated and obtained. By measuring the fluidity value 4 measured by performing the fluidity test on the coal ash slurry 3 obtained, determining the density of the fly ash, and introducing the fluidity value 4 into the correlation equation 2 The unit water amount W4 blended in the coal ash filler slurry is determined, and the fly ash amount blended in the coal ash filler slurry is determined from the cement amount blended, the determined unit water amount W4, and the density of the fly ash. A method for blending and designing coal ash filler, characterized by comprising the steps of : Furthermore, a correlation equation 3 of the change amount of the unit water amount W2 with respect to the change amount of the fluidity value 2 of the coal ash cement mixed slurry 2 is derived, and the fluidity test is performed on the coal ash filler slurry to perform the fluidity. The numerical value 5 is measured, the difference (Δx) between the fluidity numerical value 5 and the predetermined fluidity numerical value 3 is calculated, and the correlation formula 3 is used to calculate the difference (Δx) from the calculated fluidity numerical value. The unit water amount is increased or decreased (ΔW4), and the unit water amount W4 to be blended is increased or decreased so that a coal ash filler slurry having a predetermined fluidity value of 3 is obtained. and determining the amount of wood, mix design method of coal ash filler of claim 1.

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