JP2015067481A - Method for preparing packing material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for preparing a packing material, in which a blending quantity of cement, that of a neutralized precipitate and that of construction surplus soil can be decided easily so that the packing material, which is prepared by blending the cement, the neutralized precipitate and the construction surplus soil, has predetermined flowability and material strength.SOLUTION: The packing material is prepared by blending the cement, the neutralized precipitate, the construction surplus soil and water and satisfies a target value of the flowability (JH flow) after the predetermined time passes since the blending work and another target value of the uniaxial compressive strength (hardened body strength) at the material age of 28 days. The method for preparing the packing material comprises the steps of: deciding the unit quantity of each of the cement, the neutralized precipitate, the construction surplus soil and the water according to the expression (1): W=α×JH+β×ω-γ×s+δ, the expression (2): ω=(P×pl/100×ω/100)+(B×cl/100×ω/100)σ=n×C/W+m and the expression (3): P+C+B+W=1000; and blending the cement, the neutralized precipitate, the construction surplus soil and the water on the basis of the decided unit quantities to prepare the packing material.

Description

The present invention relates to a method for producing a filling material using neutralized precipitated starch and construction residue. Filling materials using neutralized sediments and construction residual soil are being studied as filling materials for filling mine tunnels. The present invention relates to a method for producing such a filling material.

In an abandoned mine, it is known that heavy metals contained in the ore are oxidized in an aerobic atmosphere and eluted into the wastewater in underground spaces such as tunnels. Deposits generated in the process are disposed of in landfills. As the amount of water flowing through the mine increases due to rainfall, etc., the amount of sediment generated increases.

Then, the method of filling the underground space such as a tunnel and reducing the amount of water flowing in the tunnel has been studied, and the underground space or underground tunnel filling method as in Patent Document 1 and Patent Document 2 has been proposed. The filler used in these construction methods is required to have high fluidity and material separation resistance. Patent Document 3 describes a highly fluid treated soil used for backfilling.

JP-A-9-125900 JP 2002-81054 A JP 2013-64314 A

In a large-scale mine, the distance from the place where the filling material is produced to the injection port becomes long, so that the filling material is advantageously pumped. Moreover, if the deposit generated in the wastewater treatment process can be used as a part of the filling material, landfill disposal becomes unnecessary, and the burden on the environment is greatly reduced. As the filling material, fluidized soil consisting of cement or cement-based solidified material, sediment, soil and water, etc. can be considered, but the nature of the sediment varies depending on the mine, and the soil varies depending on the place of acquisition. The blending for obtaining the fluidity of the resin was different, and there was a problem that it was difficult to determine the blending.

The present invention solves the above-described conventional problems, and easily determines a blending material that can obtain a predetermined fluidity and material strength for a filling material using cement, neutralized sediment, construction residue, and water. The manufacturing method which can do is provided.

This invention is a manufacturing method of the filling material which consists of the following structures.
<1>
In the filling material composed of cement, neutralized sediment, construction residual soil, and water, the flowability (JH flow) after lapse of a predetermined time from kneading and uniaxial compressive strength (hardened body strength) at the age of 28 days For the filling material satisfying the target value, the unit amount of each material is determined according to the following formula [1], formula [2] and formula [3], and the above materials are blended based on the determined unit amount. A method for producing a filling material.
W = α × JH + β × ω _L −γ × s + δ (1)
However, ω _L = [P × pl / 100 × ω _Lp / 100] + [B × cl / 100 × ω _Lcl / 100]
α, β, γ, δ: Experimental constant W: Unit water volume (kg / m ³ )
JH: JH flow value (mm) after elapse of a predetermined time from kneading
P: Amount of neutralized precipitate (kg / m ³ )
pl: Less than 75 μm portion (% by mass) in the neutralized precipitate
ω _Lp : Water content ratio at the liquid limit of neutralized precipitate (% by mass)
B: Construction soil volume (kg / m ³ )
cl: Less than 75μm (mass%) in construction soil
s: 75 μm or more portion (kg / m ³ ) in neutralized sediment and construction residual soil
ω _Lcl : _Moisture content ratio (% by mass) at the liquid limit of construction _residual soil

σ ₂₈ = n × C / W + m [2]
However, σ ₂₈ : Hardened body strength at the age of 28 days (N / mm ² )
n, m: Constant based on blending test C: Unit cement amount (kg / m ³ )

P _V + C _V + B _V + W = 1000 (3)
However, P _V : neutralized sediment volume (L / m ³ )
C _V : Cement capacity (L / m ³ )
B _V : Construction soil capacity (L / m ³ )

The manufacturing method of the filling material of this invention includes the following aspects.
<2>
The method for producing a filling material according to <1>, wherein the material separation resistance (bleeding rate: 5% or less) is determined according to the following formula [4] based on the unit water amount and the fine particle volume.
Unit water volume / fine-grained volume <8 (4)
(The fine grain volume is the total of the fine grain volume of cement, neutralized sediment and construction residual soil)
<3>
The method for producing a filling material according to the above <1> or <2>, wherein the water impermeability (water permeability coefficient of 1 × 10 ⁻⁵ cm / s or less) is determined according to the following formula [5] based on the fine particle volume.
Fine grain volume> 100L / m ³ [5]
(The fine grain volume is the total of the fine grain volume of cement, neutralized sediment and construction residual soil)

[Specific description]
Hereinafter, the present invention will be specifically described. Unless otherwise specified, the amount is mass (dry mass excluding water), and% is based on mass.

In general, the fluidity of a slurry composed of a particulate material and water varies as follows. Here, the fine particles are particles having a particle size of less than 75 μm, and the coarse particles are particles having a particle size of 75 μm or more.
(A) The fluidity of the slurry increases as the unit water amount W of the slurry increases, and decreases as the unit water amount W decreases.
(B) When the amount ratio of the particulate material and water is constant, the fluidity of the slurry decreases as the particle size of the particulate material is smaller (the finer amount in the unit amount is larger).
(C) In a system in which cement (fine particles) and sand (coarse particles) are mixed, such as cement mortar, when the amount of water is constant, the ratio of the fine particles to the coarse particles affects the fluidity.

In the above (b), there is an amount of water necessary for the fine particles to flow, and this water amount is based on the water content and the fine particle content at the liquid limit of the fine particles. In general, the liquid limit is measured in a test for particles less than 425 μm, but the water content required for fluidization is mainly the amount of water required by the fine particles. Moisture content at time) x (fine grain content).

In the filling material consisting of cement, neutralized sediment, construction residue, and water, the fine particles are contained in the neutralization residue, construction residue, and cement, where the cement is liquid with a hydration reaction after addition. Since the limit is indefinite, it is excluded, and the amount of water related to the fine particles is determined based on the total amount of fine particles of the neutralized residue and construction residual soil and the water content of each liquid limit.

In the above (c), when the fine particles and the coarse particles are mixed, if the ratio of the coarse particles is high, the particles easily flow and the amount of water for obtaining the desired fluidity is small. Therefore, the amount of water for obtaining the desired fluidity is determined by subtracting the amount based on the coarse particles. This amount of coarse particles is the total amount of coarse particles of neutralized residue and construction residual soil.

Based on the above study, the present invention is based on the above study, in a filling material composed of cement, neutralized sediment, construction residual soil, and water, the flowability (JH flow) after the lapse of a predetermined time from kneading and the unit amount of each material. It has been found that the relationship can be expressed by the following formula [1]. Furthermore, using the relational expression [2] between the cement water ratio and the hardening body strength and the expression [3] indicating that the volume sum of each material becomes the unit capacity of the filling material, After determining the amount of the neutralized precipitate, it was found that the blending of the above materials can be determined from the formula [1], the formula [2] and the formula [3].
W = α × JH + β × ω _L −γ × s + δ (1)
However, ω _L = [P × ω _Lp / 100] + [B × cl / 100 × ω _Lcl / 100]
α, β, γ, δ: Experimental constant W: Unit water volume (kg / m ³ )
JH: JH flow value (mm) after elapse of a predetermined time
P: Amount of neutralized precipitate (kg / m ³ )
ω _Lp : Water content ratio at the liquid limit of neutralized precipitate (% by mass)
B: Construction soil volume (kg / m ³ )
cl: Less than 75μm (mass%) in construction soil
s: 75μm or more in the construction residual soil (kg / m ³ )
ω _Lcl : _Moisture content ratio (% by mass) at the liquid limit of construction _residual soil

σ ₂₈ = n × C / W + m [2]
However, σ ₂₈ : Hardened body strength at the age of 28 days (N / mm ² )
n, m: Constant based on blending test C: Unit cement amount (kg / m ³ )

P _V + C _V + B _V + W = 1000 (3)
However, P _V : neutralized sediment volume (L / m ³ )
C _V : Cement capacity (L / m ³ )
b _V : Construction residual soil capacity (L / m ³ )

In the above formula [1], since there are generally few coarse particles contained in the neutralized precipitate, the coarse particle portion is omitted. If the neutralized precipitate contains coarse particles, the amount of water at the liquid limit is calculated for fine particles, and the amount of coarse particles in the neutralized precipitate is added to the amount of coarse particles in the construction residual soil. In this case, the amount of water at the liquid limit is given by the following equation. Further, s in the formula [1] is the total amount (kg / m ³ ) of the portion of 75 μm or more in the neutralized precipitate and the construction residual soil.
ω _L = [P × pl / 100 × ω _Lp / 100] + [B × cl / 100 × ω _Lcl / 100]
pl: Less than 75 μm portion (% by mass) in the neutralized precipitate
In addition, in the blending design according to the formula [1], the water content, the fine particle amount, and the coarse particle amount at the liquid limit are measured in advance for the neutralized precipitate and construction residual soil to be used.

Prior to the blending design of the filling material, the experimental constants α, β, γ and δ of the above equation [1] are determined by a prior test for the neutralized precipitate, cement, construction residual soil and water to be used. This preliminary test may be performed within a range where the above experimental constants are obtained.

For example, based on the data of Example 1, the following multiple regression equation is obtained for the relationship with the flow value for 90 minutes after kneading (determination coefficient 0.961).
W = 0.337 × JH (90) + 0.159 × ω _L −0.222 × s + 667.982.

Further, for example, the following multiple regression equation is obtained for the flow value immediately after kneading (determination coefficient 0.962).
W = 0.296 × JH (0) + 0.274 × ω _L −0.191 × s + 598.633
Further, for example, the following multiple regression equation is obtained for the flow value after 60 minutes of kneading (determination coefficient 0.964).
W = 0.317 × JH (60) + 0.170 × ω _L −0.219 × s + 658.308

From the above formula [2], the cured body strength at the age of 28 days is shown from the ratio of the unit water amount W and the unit cement amount C. N and m in the formula [2] are constants based on the blending test. For the neutralized precipitates A and B used in the examples, the constants n and m based on the blending test are, for example, as follows.
(I) For neutralized precipitate A, n in the unit amount of 44 kg / m ³ of the neutralized precipitate is 6.905, m is -0.453, n in the unit amount of 132 kg / m ³ is 0.970, m is −0.055, and the formula [2] is as follows.
σ ₂₈ = 6.905 × C / W−0.453
σ ₂₈ = 0.970 × C / W−0.055
(B) Regarding the neutralized precipitate B, n in the unit amount of 45 kg / m ³ of the neutralized precipitate is 4.610, m is -0.268, n in the unit amount of 135 kg / m ³ is 0.470, m is -0.039, and the formula [2] is as follows.
σ ₂₈ = 4.610 × C / W−0.268
σ ₂₈ = 0.470 × C / W−0.039

Here, the properties of the neutralized precipitate vary depending on the mine where it is generated. In addition, the strength expression varies depending on the unit amount of the neutralized precipitate. Therefore, the constants n and m by the blending test of the above formula [2] are determined by a prior test in which the ratio of the unit water amount W and the unit cement amount C to which the unit amount of the neutralized precipitate that is the subject of the blending design is added is changed. Find in advance.

The unit capacity of each material in the filling material is shown by the above equation [3].

Based on the unit water amount W and the fine particle volume X, the material separation resistance (bleeding rate 5% or less) can be determined according to the following equation [4]. When W / X is 8 or more, the material separation resistance becomes low and the bleeding rate exceeds 5%. For example, when construction residual soil contains fine grains, the amount of cement is corrected by increasing the amount of construction residual soil. To correct the formulation.
Unit water amount W / fine-grained volume X <8 (4)
(The fine grain volume is the total of the fine grain volume of cement, neutralized sediment and construction residual soil)

Based on the fine particle volume X, water impermeability (water permeability 1 × 10 ⁻⁵ cm / s or less) can be determined according to the following equation [5]. If X is less than 100 L / m ³ , the water-imperviousness will be insufficient and the water permeability will exceed 1 × 10 ^-5 cm / s. For example, if the construction soil contains fine particles, increase the amount of construction soil. Correct the formulation or increase the amount of cement to correct the formulation.
Fine grain volume X> 100L / m ³ [5]
(The fine grain volume is the total of the fine grain volume of cement, neutralized sediment and construction residual soil)

Based on α, β, γ, δ, and n, m determined by prior tests, cement, neutralized sediment, construction residual soil by the formulation determined according to formula [1], formula [2] and formula [3] , And water to produce a filling material. In addition, when a predetermined bleeding rate (material separation resistance) and water permeability coefficient (water-imperviousness) are determined, the formulation is re-examined using Formula [4] and Formula [5], and the fine soil fraction in the construction residual soil If it contains, the unit amount of construction residual soil is set. If not, the unit amount of cement is set, and the blending is determined again based on the equations [1], [2] and [3].

In the present invention, as the cement, early-strength Portland cement, ordinary Portland cement, medium heat Portland cement, low heat Portland cement, blast furnace cement, fly ash cement, cement-based solidified material, and the like can be used.

In the present invention, neutralized precipitates generated by neutralizing mine wastewater can be used as neutralized precipitates. The remaining construction soil can be used as it is due to construction work. As the kneading water, tap water, the supernatant water of the neutralized precipitate, or the like can be preferably used. Additives such as chemical admixtures can be used as necessary to adjust fluidity, adjust setting time or reduce material separation.

According to the present invention, the filling material composed of cement, neutralized sediment, construction residual soil and water can be easily determined, and a filling material having a target fluidity can be easily manufactured.

The graph which shows the relationship between the unit water quantity when the target fluidity (JH flow value after 90 minutes of kneading | mixing) is 300 mm, and the unit water quantity obtained by the multiple regression equation (Formula [1]).

The materials used in the examples of the present invention are shown below.
<Cement> Blast Furnace Cement Class B, fine grain content is 100%
<Neutralized precipitate> Neutralized precipitates A (Mine A) and B (Mine B) generated by neutralizing mine wastewater were used. Table 1 shows the physical properties of the neutralized precipitates A and B.
Neutralized precipitate A (water content limit water content 120.2%, fine particle content is substantially 100%)
Neutralized precipitate B (liquid content limit water content 198.4%, fine grain content 63%)
In the regression analysis of the neutralized precipitate B, the amount of fine particles of the neutralized precipitate is 63%, the amount of coarse particles is 37%, and the amount of water at the liquid limit is calculated for fine particles. The amount of coarse particles was added to the amount of coarse particles in the construction residual soil.

<Remaining construction soil> Sandy soil and clay soil having physical properties shown in Table 2 were used alone and in combination.
Sandy soil [moisture content of liquid limit 0% (measurable), fine grain content is substantially 0%]
Viscous soil (water content limit water content 64.4%, fine grain content is substantially 100%)
<Other materials> Tap water was used as the kneading water.

<Fluidity test>
The flow value (JH flow) was measured by the former Japan Highway Public Corporation Standard “Testing method of air mortar and air milk” 1.2 cylinder method (JHS A 313-1992).
<Material separation resistance>
According to Japan Society of Civil Engineers JSCE-F 522-2007 "Testing method for bleeding rate and expansion rate of pre-packed concrete mortar (polyethylene bag method) (draft)", the presence or absence of bleeding after 3 hours from kneading was confirmed.
<Strength properties>
According to JIS A 1216: 2009 “Soil uniaxial compression test method”, the strength of the hardened material was measured at 7 days and 28 days.
<Water permeability test>
It was measured by a water level permeability test of JIS A 1218: 2009 “Soil permeability test method”.

[Example 1]
Experimental constants α, β, γ of the formula [1] immediately after kneading, 60 minutes after kneading, and 90 minutes after kneading by multiple regression analysis using test results with 189 formulations including the formulations exemplified in Table 3 and Table 4 , Δ were derived, respectively.

After 90 minutes of kneading, α, β, γ, and δ were 0.337, 0.159, 0.222, and 667.982, respectively, and equation [1] was as follows (multiple regression equation Coefficient of determination 0.961).
W = 0.337 × JH (90) + 0.159 × ω _L −0.222 × s + 667.982.
Similarly, immediately after kneading, the following equation is obtained (determination coefficient 0.962 of the multiple regression equation).
W = 0.296 × JH (0) + 0.274 × ω _L −0.191 × s + 598.633
60 minutes after kneading was as follows (decision coefficient 0.964 of multiple regression equation).
W = 0.317 × JH (60) + 0.170 × ω _L −0.219 × s + 658.308

In sample A-4 in Table 3, the water content ratio ω _{Lp at} the liquid limit of the neutralized precipitate is 120.2%, and the water content ratio ω _{Lcl at} the liquid limit of the construction residual soil (viscous soil) is 64. Since it is 4%, ω _L is given by the following equation.
ω _L = [P × ω _Lp / 100 + B × ω _Lcl / 100]
Further, since the amount P of the neutralized precipitate A is 88 kg / m ³ and the amount B of the construction residual soil (cohesive soil) is 297 kg / m ³ , ω _L is as follows.
ω _L = 88 × 120.2 / 100 + 297 × 64.4 / 100 = 297
Next, since the mass s of the 75 μm or more portion of the construction residual soil (cohesive soil) is substantially 0% (the amount of fine particles is substantially 100%), s = 0. If the target value of JH (90 minutes after kneading) is 300 mm, the unit water amount W is given by the following equation.
W = 0.337 × 300 + 0.159 × 297−0.222 × 0 + 667.982 = 816.3
Since the unit water amount of Sample A-4 in Table 3 is 807 kg / m ³ , the unit water amount obtained based on Equation [1] is close to the unit water amount shown in Table 3, and Equation [1] is highly reliable. confirmed.

FIG. 1 shows the relationship between the unit water amount and the unit water amount calculated based on the equation [1] (unit water amount obtained from the multiple regression equation in the figure). As shown in the figure, these unit water amounts are distributed almost linearly, indicating a good match.

In sample B-5 in Table 4, the fine particle content of the neutralized precipitate is 63%, the water content ratio ω _Lp of the liquid limit is 198.4%, and the water content ratio of the liquid limit of the construction residual soil (viscous soil) Since ω _Lcl = 64.4%, ω _L is given by the following equation.
ω _L = [P × pl / 100 × ω _Lp / 100 + B × ω _Lcl / 100]
Next, since the amount P of the neutralized precipitate B is 135 kg / m ³ and the amount B of the construction residual soil (cohesive soil) is 190 kg / m ³ , ω _L is as follows.
ω _L = 135 × 63/100 × 198.4 / 100 + 190 × 64.4 / 100 = 291
Moreover, although the mass s of the 75 μm or more portion of the construction residual soil (viscous soil) is substantially 0% (the fine particle content is substantially 100%), the coarse particle content of the neutralized precipitate B is 37%. s = 135 × 37/100 = 50. If the target value of JH (90 minutes after kneading) is 300 mm, the unit water amount W is given by the following equation.
W = 0.337 × 300 + 0.159 × 291-0.222 × 50 + 667.982 = 804
Since the unit water amount of Sample B-5 is 842 kg / m ³ , the unit water amount obtained based on Equation [1] is close to the unit water amount shown in Table 3, and it was confirmed that Equation [1] is highly reliable. .

[Example 2]
The target fluidity (JH flow value after 90 minutes of kneading) is set to 300 mm. In the neutralized precipitate A, the dry unit mass of the neutralized precipitate is 132 (kg / m ³ ), and in the neutralized precipitate B, 135 (kg / m ³ ), uniaxial compressive strength at the age of 28 days is 0.04 (N / mm ² ), sandy clay and cohesive soil are used as construction residual soil, and 4 combinations of filling materials according to the following formula (Table 5 No. 1) ~ 4) was calculated.
W = 0.337 × JH (90) + 0.159 × ω _L −0.222 × s + 667.982.
σ ₂₈ = 0.970 × C / W−0.055 (neutralized precipitate A)
σ ₂₈ = 0.470 × C / W−0.039 (neutralized precipitate B)
P _V + C _V + B _V + W = 1000

As a result of the blending calculation, in the sandy soil (No. 1 and No. 3 in Table 5), both of the neutralized precipitates A and B satisfy the conditions of the equations [4] and [5] because the amount of fine particles is insufficient. Because there was not, the amount of cement was increased to correct the formulation, and the unit mass was determined. The results are shown in Table 5. Filling materials were produced according to the formulations in Table 5. Table 6 shows the JH flow value, bleeding rate, uniaxial compressive strength, and water permeability of the produced filling material.
As shown in Table 6, the JH flow value after 90 minutes of kneading of the produced filling material was very close to the target fluidity, and bleeding after 3 hours did not occur, and a filling material having sufficient strength was obtained. .

According to the present invention, since it is possible to easily determine the composition of the filling material composed of cement, neutralized sediment, construction residual soil, water, and the like, it becomes possible to easily manufacture the filling material having the target fluidity, It is useful above.

Claims (3)

In the filling material composed of cement, neutralized sediment, construction residual soil, and water, the flowability (JH flow) after lapse of a predetermined time from kneading and uniaxial compressive strength (hardened body strength) at the age of 28 days For the filling material satisfying the target value, the unit amount of each material is determined according to the following formula [1], formula [2] and formula [3], and the above materials are blended based on the determined unit amount. A method for producing a filling material.

W = α × JH + β × ω _L −γ × s + δ (1)
However, ω _L = [P × pl / 100 × ω _Lp / 100] + [B × cl / 100 × ω _Lcl / 100]
α, β, γ, δ: Experimental constant W: Unit water volume (kg / m ³ )
JH: JH flow value (mm) after elapse of a predetermined time from kneading
P: Amount of neutralized precipitate (kg / m ³ )
pl: Less than 75 μm portion (% by mass) in the neutralized precipitate
ω _Lp : Water content ratio at the liquid limit of neutralized precipitate (% by mass)
B: Construction soil volume (kg / m ³ )
cl: Less than 75μm (mass%) in construction soil
s: 75 μm or more portion (kg / m ³ ) in neutralized sediment and construction residual soil
ω _Lcl : _Moisture content ratio (% by mass) at the liquid limit of construction _residual soil

σ ₂₈ = n × C / W + m [2]
However, σ ₂₈ : Hardened body strength at the age of 28 days (N / mm ² )
n, m: Constant based on blending test C: Unit cement amount (kg / m ³ )

P _V + C _V + B _V + W = 1000 (3)
However, P _V : neutralized sediment volume (L / m ³ )
C _V : Cement capacity (L / m ³ )
B _V : Construction soil capacity (L / m ³ )
The method for producing a filling material according to claim 1, wherein the material separation resistance (bleeding rate: 5% or less) is determined according to the following formula [4] based on the unit water amount and the fine particle volume.
Unit water volume / fine-grained volume <8 (4)
(The fine grain volume is the total of the fine grain volume of cement, neutralized sediment and construction residual soil)
The method for producing a filling material according to claim 1 or 2, wherein the water-imperviousness (water permeability coefficient of 1 x ^10-5 cm / s or less) is determined according to the following formula [5] based on the fine particle volume.
Fine grain volume> 100L / m ³ [5]
(The fine grain volume is the total of the fine grain volume of cement, neutralized sediment and construction residual soil)

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