JP4705658B2 - Adjustment method of mud viscosity - Google Patents

Description

  The present invention relates to a method for adjusting the viscosity of muddy water used in a shield method, a pile method, a fluidization method, an underground continuous wall method and the like in the construction field.

  Muddy water used in the shield method, pile method, fluidization method, underground wall method, etc. in the construction field will affect the ground at the construction site, so stable quality is required. It is done. For this reason, the muddy water is required to have a predetermined viscosity according to the purpose of use.

  The viscosity of the mud can be evaluated by using, for example, the Japan Society of Civil Engineers standard "Testing method for fluidity of mortar of prepacked concrete (method using P funnel) (JSCE-1986)" (for example, Patent Document 1). And 2).

In this test method, a fixed volume of 1725 cm ³ of muddy water filled in a P funnel 2 known as a funnel-shaped, funnel-shaped measuring funnel shown in FIG. The time is measured, and it is considered that the lower the muddy water viscosity is, the longer the flowing time is, and the viscosity of the muddy water is relatively evaluated based on the above flowing time. This test method is often used when making muddy water at a construction site.
JP-A-2005-233792 JP 2006-77522 A

  However, the conventional muddy water viscosity test (hereinafter referred to as “conventional P funnel”) using the above-mentioned Standards of the Society of Civil Engineers “Testing method for fluidity of mortar of prepacked concrete (method using P funnel) (JSCE-1986)”. In the test of mud viscosity by the "", the viscosity is evaluated appropriately because the density of the mud does not only affect the viscosity of the mud but also its density, which is independent of this viscosity. There was a problem that could not be done.

  That is, in this test method, the muddy water has a longer flow time as its viscosity is higher, but even when its density is high, the flow time is also longer, and therefore the viscosity cannot be properly evaluated. was there.

  In this way, in the mud water viscosity test using the conventional P funnel, the density of the mud water will affect the flow time as a unique factor separately from the viscosity for the following reasons. it is conceivable that.

  As shown in FIG. 10, the muddy water is configured to include soil particle components of fine-grained soil and coarse-grained soil, and water. Here, the fine-grained soil refers to soil particles having a particle size of 75 μm or less, and the coarse-grained soil refers to soil particles having a particle size of 75 μm or more. Moreover, the muddy water at the time of comprising virtually only the fine-grained soil and water component in muddy water is called fine-grained muddy water.

  The viscosity of the entire mud is exhibited based on fine-grained soil among the soil particle components contained in the mud, and the coarse-grained soil does not contribute to the viscosity of the mud. For this reason, the viscosity of muddy water is actually determined only by the portion of the fine-grained muddy water. That is, the viscosity of the muddy water is determined based on the relative ratio between the fine-grained soil constituting the fine-grained muddy water and the water.

On the other hand, the density of muddy water is determined by the ratio of water to the whole soil particles obtained by adding the fine-grained soil and coarse-grained soil in the muddy water. The density of the fine-grained soil and the coarse-grained soil is approximately 2.7 g / cm ³ , and the density of water is 1 g / cm ³ .

  Therefore, for example, even if the muddy water has the same density, the viscosity of the soil particle component is different from each other, that is, the composition ratio of the fine-grained soil and the coarse-grained soil is different from each other. May be different from each other. On the other hand, even if the muds have the same viscosity, the densities may be different from each other.

  On the other hand, as described above, the higher the density of the muddy water, the longer the flow-down time in the viscosity test of the muddy water by the conventional P funnel. This can be explained using Poiseuille's law. According to Poiseuille's law, the following relationship is generally established between the flow rate and the pressure difference in the tubular flow path.

  When the above formula 1 is applied to the conventional mud viscosity test using a P funnel, if the volume of the mud filled in the P funnel 2 is V and the flow time is s, the flow time s is muddy water. S = V / Q from the volume V and the flow rate Q in Equation 1 above.

  Further, ΔP in the above formula 1 can be considered as a difference (P1−P2) between the pressure P1 of the upper surface of the muddy water filled in the P funnel 2 and the pressure P2 at the discharge port of the P funnel 2. Thereby, the following numerical formula 2 can be obtained.

8L / πr ⁴ in Equation 2 is a constant value because it is determined by the shape of the P funnel 2. Further, P2 in the above equation 2 is P2 = 2a × γt, where a is the cross-sectional area of the pipe, γt is the density of muddy water in the P funnel 2, and h is the average height of muddy water in the P funnel 2. Since it can be expressed as xh, the pressure P2 increases as the density γt increases. Further, P1 in the above formula 2 is a constant value. For this reason, as the density γt increases, the value of ΔP = (P1−P2) in the above equation 2 decreases, so the flow-down time s increases.

  In order to verify the relationship between the density of the muddy water and the flow time, a muddy water viscosity test using a conventional P funnel was actually performed on muddy water having the same viscosity but different densities.

FIG. 11 shows that for each different density γt by changing the density γt by adding sand in the surface dry state to the muddy water having an initial density γt = 1.20 g / cm ^3. FIG. 5 is a diagram in which the correlation between the density γt and the flow time s when the flow time s was measured by testing the viscosity of mud water using a conventional P funnel was examined. As shown in the figure, even if the viscosity of the muddy water is the same, the result is that the flow time becomes longer as the density becomes higher.

  In addition, each of the muddy water whose density γt was changed by adding sand in the dry state, the viscosity torque when rotating the rotor submerged in the muddy water after separating the sand in the muddy water by sieving. By measuring the viscosity using a B-type viscometer (Brookfield viscometer) to be measured, it has been confirmed that the viscosity is almost the same as the initial mud viscosity before adding sand in the dry state. . Therefore, it can be determined that the viscosity of each muddy water whose density γt has been changed by adding sand in the dry state is not increased in viscosity due to adsorption of moisture during the addition of sand.

  Therefore, as can be seen from these verification tests, in the mud viscosity test using the conventional P funnel, as described above, not only the viscosity of the mud but also its density is unique. There is a problem in that the viscosity cannot be properly evaluated because the flow time is affected as a factor.

  In addition, the conventional mud viscosity test using a P funnel is intended to mute the mud density, but even if it is determined whether the mud viscosity is appropriate or not, the mud viscosity is inadequate. If it was evaluated as appropriate, then it was not possible to directly determine how much added water was needed for the mud to exhibit the required viscosity.

  For this reason, if it is evaluated that the viscosity of the muddy water is inappropriate, when the viscosity is insufficient, the water content and the particle size composition (such as the composition ratio of fine and coarse soil) for each muddy water, one by one After the measurement, the amount of added water necessary for the mud water to exhibit a predetermined viscosity had to be calculated based on the water content and the particle size composition. In addition, when the viscosity was excessive, it had to be gradually adjusted until the required viscosity was reached. Therefore, in the conventional mud viscosity test using a conventional P funnel, the test results were compared with the quality of the mud. There was a problem that it could not be directly reflected in the stabilization of.

  In addition, if it is evaluated that the viscosity of the muddy water is inappropriate, as described above, in order to determine how much added water is required for such muddy water, Since the particle size composition must be measured step by step, the production of mud at the construction site must be interrupted until these measurements are completed, or it must be adjusted while gradually adding water until the desired viscosity is reached. It was. For this reason, there was a problem that the production efficiency of muddy water at the construction site could not be improved.

  Therefore, in view of the above problems, the present invention can evaluate the viscosity without being affected by the increase or decrease in the amount of coarse-grained mud water whose particle size configuration varies, and directly determine the amount of water added to obtain the required viscosity. It is an object of the present invention to provide a method for adjusting the viscosity of muddy water, which can quickly stabilize the quality of muddy water and improve productivity.

In order to solve the above problems, the method for adjusting the viscosity of the muddy water according to the present invention is as follows.
For each muddy water whose ratio of water content and fine soil weight is different from each other, we conducted a flow test to measure the flow time of a constant weight of muddy water. Create a correlation document by measuring the correlation between
For muddy water whose viscosity is unknown, the flow time is measured by the flow method test, and based on the correlation data, the ratio of the amount of water added to the flow time and the weight of fine-grained soil and the required viscosity are exhibited. From the relative ratio of the amount of water to be added and the ratio of the fine-grained soil weight, the amount of water to be increased or decreased is derived and adjusted.

  The method for adjusting the viscosity of muddy water according to the present invention is characterized in that the correlation material is created for each diameter of the discharge port of the funnel used in the flow-down method test.

According to such a method for adjusting the viscosity of the muddy water of the present invention,
For each muddy water whose ratio of water content and fine soil weight is different from each other, we conducted a flow test to measure the flow time of a constant weight of muddy water. Create a correlation document by measuring the correlation between
For muddy water whose viscosity is unknown, the flow time is measured by the flow method test, and based on the correlation data, the ratio of the amount of water added to the flow time and the weight of fine-grained soil and the required viscosity are exhibited. From the relative ratio of the amount of water to become and the ratio of the weight of fine-grained soil, by deriving and adjusting the amount of water to increase and decrease,
Viscosity can be evaluated without being affected by the increase or decrease in the amount of coarse-grained mud water whose particle size composition varies, and the amount of water added to obtain the required viscosity can be directly determined. It can be stabilized quickly and muddy water productivity can be improved.

Further, according to the method for adjusting the viscosity of the muddy water of the present invention, the correlation material is created for each diameter of the discharge port of the funnel used in the flow-down method test,
Muddy water that is put into the funnel according to the case where the viscosity is not exhibited unless the density of the muddy water is increased due to the difference in soil quality or the case where the viscosity is sufficiently exhibited even if the density is low. Even if the volume of the sample is reduced or increased, the flow time can be lengthened to reduce the relative measurement error, or the flow time can be prevented from becoming longer than necessary. As a result, the mud can be adjusted to a stable quality. Moreover, the influence of the difference in the skill of the measurer who performs the flow method test can be reduced.

Hereinafter, the best mode for carrying out the method for adjusting the viscosity of muddy water according to the present invention will be specifically described with reference to the drawings.
FIG. 1 to FIG. 5 are diagrams which are referred to for explaining a method for adjusting the viscosity of muddy water according to an embodiment of the present invention.

  In the method for adjusting the viscosity of mud water according to the present embodiment, the viscosity of the mud water in the series of steps described later is measured in the same manner as the mud water viscosity test using the conventional P funnel described above. Therefore, the viscosity of the muddy water is measured by replacing it with the flow time. Here, in the conventional method, the volume of the muddy water filled in the P funnel 2 shown in FIG. 9 is constant, whereas in the method for adjusting the viscosity of the muddy water according to the present embodiment, the volume of the muddy water is Regardless of the increase or decrease, the weight is kept constant.

  In the following description, such a test for measuring the flow time of a constant weight of mud filled in the P funnel 2 will be referred to as a flow test by the P funnel. In this flow-down type test using a P funnel, the P funnel 2 is filled with 1725 g of muddy water having a constant weight, and the flow time is measured.

  In such a flow-down type test using a P funnel, as described above, the P funnel 2 is filled with a certain amount of muddy water and the flow time is measured. Therefore, V / (P1 The fluctuation of the value of -P2) is suppressed and stabilized with respect to the increase and decrease of the density γt of the muddy water.

  Therefore, in the flow-down method test using the P funnel in which the muddy water is filled in the P funnel 2 by a certain weight, the correlation between the viscosity η and the flow time s in the above equation 2 becomes very strong. Proportional.

  Next, the method for adjusting the viscosity of the muddy water according to the present embodiment is performed according to the following procedure. First, as a preparation for enabling the method for adjusting the viscosity of mud water according to the present embodiment to be used at the construction site, the amount of mud water added and the weight ratio of fine-grained soil are determined by laboratory tests. Then, the diagram (corresponding to the correlation material) shown in FIG. 1 showing the correlation with the flow time is created.

  In order to create the diagram shown in FIG. 1, first, the particle size constitution (granular soil distribution) of soil used for producing mud or unadjusted dense mud is measured. Moreover, using this soil or unadjusted thick mud, a plurality of types of mud with different amounts of water (water content) are prepared, and the density of each of these muds is measured. And about each of these mud water, based on the density and a particle size structure, each of the weight of the amount of water contained per unit weight and the weight of fine-grained soil is calculated.

  Moreover, about each of these muddy water, the flowing-down time is measured by performing the flowing-down system test by P funnel. This flow-down type test using the P funnel is performed by filling the P funnel 2 with a certain weight of muddy water.

  Next, as shown in FIG. 1, a diagram showing the correlation between the amount of water in the mud and the weight ratio of the fine-grained soil and the flow time is created. Also, the weight ratio between the amount of water and the fine-grained soil at which the mud exhibits the required viscosity is determined. This is the preparation, and the muddy water production at the construction site is performed after such preparation. The viscosity of the muddy water produced at the construction site is adjusted based on the diagram of FIG.

  That is, when adjusting the viscosity of the temporarily produced muddy water at the construction site, first, the flow time is measured by conducting a flow method test using a P funnel for such a temporarily produced muddy water. The flow-down system test using the P funnel for the temporarily produced mud is performed by filling the P funnel 2 with a certain weight of mud.

  Then, from the diagram of FIG. 1, the value of the weight ratio between the amount of water added and the fine-grained soil corresponding to the flow time measured in this way is read, and the value read in this way and the muddy water exhibits the required viscosity. Based on the relative ratio between the amount of added water and the weight ratio of fine-grained soil, the amount of water required for adjusting the viscosity of the mud is determined.

  For example, as shown in (a) of FIG. 2, the standard composition of muddy water whose viscosity is appropriate according to laboratory tests, when the amount of water added is 150, the amount of fine-grained soil is 100. It is assumed that such a ratio, that is, the weight ratio between the amount of water added and fine-grained soil is 1.5. When such a muddy water having a standard composition is subjected to a flow-down test using a P funnel, the flow-down time is 9.3 seconds as shown in FIG.

  And, at the construction site, if the muddy water produced so as to have the same density as the muddy water of the standard composition is subjected to a flow method test using a P funnel, the flow time is 8.5 seconds. It can be seen that the viscosity of the mud is lower than that of the standard blend because the run time is shorter than that of the standard blend. In addition, as shown in FIG. 1, it can be read that the weight ratio of the amount of mud water and the fine-grained soil corresponding to the flow time of 8.5 seconds is 1.85.

  In addition, the muddy water tentatively produced at the construction site is produced so as to have the same density as the muddy water of the standard composition of (a) as shown in FIG. The amount is the same as that of the standard composition, but the weight ratio between the amount of water added and fine soil is 1.85, so the weight ratio between the amount of water added and fine soil is 1.5. In order to have the same viscosity as the mud water of a certain standard composition, the weight ratio of the amount of water added to fine soil is increased by {(1.85 / 1.5) -1} × 100≈23%. You can see that it is closed. That is, the muddy water tentatively produced at the construction site has been produced with a water content of 123%.

  For this reason, the muddy water prepared for actual use at the construction site has the same viscosity as the muddy water of the standard composition in which the weight ratio of the amount of water added to the fine-grained soil is 1.5. As shown in (c), it can be seen that the amount of water added may be adjusted to 150 / 1.23 = 121.6.

  In addition, since the diagram shown in FIG. 1 was created with respect to the muddy water produced using soil of a certain soil quality, the diagram of FIG. Separately from this, it is necessary to create a diagram similar to the diagram of FIG.

  According to such a method for adjusting the viscosity of mud water according to the present embodiment, the viscosity can be evaluated without being affected by the increase or decrease in the amount of coarse-grained soil whose particle size configuration varies, and the required viscosity is obtained. Therefore, the quality of the muddy water can be stabilized.

  Moreover, according to the method for adjusting the viscosity of the muddy water according to the present embodiment, when the muddy water is produced at the construction site, the amount of water added to obtain the required viscosity can be directly determined. Productivity can be significantly improved.

  In addition, as shown in FIG. 3, the superior effect of the mud water viscosity adjusting method according to the present embodiment is more clearly compared with the conventional mud viscosity test using a P funnel. can do.

  FIG. 3 shows a method for adjusting the viscosity of mud water according to the present embodiment for each mud having the same viscosity and different densities, and a flow method using a P funnel, and the viscosity of mud water using a conventional P funnel. It is a diagram for showing and comparing each flowing time by performing both of tests.

Here, muddy water having the same viscosity and different densities are produced by adding coarse-grained soil (silica sand) in a dry state to fine-grained muddy water having a density of 1.099 g / cm ^3. I tried to do it. These muddy waters have been confirmed to have almost the same viscosity by measuring the viscosity after removing coarse-grained soil (silica sand).

In the conventional mud viscosity test using a P funnel, the time required for a constant volume of 1725 cm ³ of mud flowing down in the P funnel 2 shown in FIG. 9 is measured. As indicated by the broken line connecting them, the flow time fluctuates as the muddy water density increases.

  On the other hand, in the flow-down method test by the P funnel of the method for adjusting the viscosity of the muddy water according to the present embodiment, the time required for the 1725 g of a constant weight of muddy water filled in the P funnel 2 to flow down is measured, As shown by the broken line connecting the square dots in FIG. 3, even when the density of muddy water changes, the flow time hardly changes.

  Therefore, according to the method for adjusting the viscosity of the mud according to the present embodiment, the viscosity can be evaluated without being affected by the increase or decrease in the amount of coarse-grained soil with varying particle size, so the quality of the mud is stabilized. Can be made.

  Further, as shown in FIG. 3 to FIG. 5, the mud is prepared based on the mud viscosity adjustment method according to the present embodiment and the mud viscosity test using the conventional P funnel. By comparing with the case, the excellent effect of the mud water viscosity adjusting method according to the present embodiment can be further clarified.

FIG. 3 is a diagram showing the flow time of muddy water having the same viscosity as described above. If the viscosity of a certain muddy water is found to be the same as the viscosity assumed in the creation of FIG. 3 by an indoor test, it is appropriate. If the density is 1.20 g / cm ³ because the muddy water blended so as to have the composition is configured as shown in FIG. As shown in FIG. 3, when the muddy water viscosity adjusting method according to the embodiment is used, a flow-down test using a P funnel is performed, the flow-down time is 12 seconds.

On the other hand, when the same muddy water was tested for the viscosity of the muddy water using a conventional P funnel, the flow time was 11.3 seconds, as shown in FIG. Therefore, when the viscosity test of mud water using a conventional P funnel is performed, the 11.3 second flowing time is shorter than the original flowing time 12 seconds, so it is erroneously determined that the viscosity is insufficient. End up. Furthermore, in order to set the flow-down time to 12 seconds, as shown in the figure, it is erroneously determined that the amount of water added must be reduced to a density of 1.31 g / cm ³ .

Under such erroneous judgment, when the muddy water having a density of 1.20 g / cm ³ is adjusted to 1.31 g / cm ³ , the amount of water added is 882 kg as shown in FIG. Will be accidentally reduced to 527kg. That is, the amount of water is mistakenly reduced by about 40%.

For this reason, in order to obtain an appropriate viscosity which is originally required, the fine-grained muddy water is 1.099 g / cm ³ (≈ 1.100 g / cm ³ ) as shown in FIG. In spite of the fact that the density is required, the mud misadjusted based on the mud viscosity test by the conventional P funnel as described above has the fine-grained mud density shown in FIG. As shown in (b), the density is adjusted to an excessively high density of 1.16 g / cm ³ .

  Inadequately adjusted muddy water has reduced fluidity and material separability, and when solidified material is added, its strength becomes too high, and quality cannot be stabilized. End up.

Next, FIG. 5 is a case where the viscosity of a certain muddy water is found to be the same as the viscosity assumed in the preparation of FIG. The case where the density is 1.50 g / cm ³ will be described because the muddy water blended to have such a viscosity is configured as shown in FIG.

When such a muddy water having a density of 1.50 g / cm ³ was subjected to a flow-down method test using a P funnel in the method for adjusting the viscosity of the muddy water according to the present embodiment, as shown in FIG. The time is approximately 12 seconds.

On the other hand, when the same mud water was tested for the viscosity of the mud water using a conventional P funnel, the flow-down time was 13.2 seconds as shown in FIG. Therefore, when the viscosity test of mud water using a conventional P funnel was performed, the 13.2 second flow time was longer than the original flow time of 12 seconds, so it was erroneously determined to be excessively viscous. End up. Furthermore, in order to set the flow down time to 12 seconds, as shown in the figure, it is erroneously determined that the amount of water added must be increased to a density of 1.31 g / cm ³ .

Under such an erroneous determination, when the muddy water having a density of 1.20 g / cm ³ is adjusted to 1.31 g / cm ³ , the amount of water added is 706 kg as shown in FIG. Will be accidentally increased to 1319 kg. That is, the amount of water will be increased by about 87% by mistake.

For this reason, in order to obtain the required appropriate viscosity originally, the fine-grained mud water is 1.099 g / cm ³ (≈ 1.100 g / cm ³ ) as shown in FIG. In spite of the fact that the density is necessary, the mud misadjusted based on the mud viscosity test by the conventional P funnel as described above has the fine-grained mud density shown in FIG. As shown in (b), the density is adjusted to an excessively low density of 0.813 g / cm ³ .

  Inadequately adjusted mud water has excessive fluidity and material separability, and when solidified material is added, its strength becomes insufficient, and quality can be stabilized. It will disappear.

  In this way, when the viscosity of the mud is adjusted by performing the test of the viscosity of the mud by using the conventional P funnel, the stabilization of the viscosity is inhibited, so that the quality can be stabilized. Although it has become difficult, according to the method for adjusting the viscosity of the muddy water according to the present embodiment, even if the muddy water has a different ratio of the coarse-grained soil, it is excluded that the coarse-grained soil affects the viscosity evaluation. By doing so, it is possible to measure the viscosity and density of fine-grained mud water, which should originally be made constant, more accurately, so that it is possible to avoid erroneously evaluating the viscosity of mud water. It is possible to stabilize the quality.

  In the method for adjusting the viscosity of the muddy water according to the present embodiment, the P funnel 2 is filled with only a constant weight of 1725 g when performing the flow-down method test using the P funnel. The muddy water filled in the funnel 2 is not limited to 1725 g as long as the weight is constant.

  Further, in the method for adjusting the viscosity of the muddy water according to the present embodiment, the P funnel 2 shown in FIG. 9 is used, which is the same as that used in the conventional muddy water viscosity test using the P funnel. Depending on the skill of the person, a funnel having a diameter different from the diameter of the discharge port of the P funnel may be used.

  For example, when the skill of the measurer is low, the measurement error of the flow time with respect to the viscosity of the muddy water can be relatively reduced by narrowing the diameter of the discharge port of the funnel to be used and extending the flow time.

  In such a case, by using the P funnel shown in FIG. 9, even if a diagram corresponding to FIG. 1 has already been created, it corresponds to the funnel in which the diameter of the discharge port is changed again. It is necessary to create a diagram corresponding to FIG. That is, when using a funnel having a different diameter of the discharge port, a diagram corresponding to FIG. 1 is created for each different diameter.

  In addition, for example, when viscosity is not exhibited unless the density of muddy water is increased due to differences in soil quality, the volume of muddy water filled in the P funnel 2 is reduced due to the high density, and the flow time is reduced. However, in such a case, a funnel having a smaller outlet diameter than the P funnel 2 may be used in the flow-down method test. . In such a case, it is necessary to create a diagram corresponding to FIG. 1 corresponding to the funnel having a small diameter of the discharge port.

  Further, when the viscosity of the muddy water is sufficiently low due to a difference in soil quality or the like, a funnel having a large discharge port may be used instead of the P funnel 2. In such a case, it goes without saying that it is necessary to create a diagram corresponding to FIG. 1 corresponding to the funnel having a larger diameter of the discharge port.

  Further, in the method for adjusting the viscosity of the mud water according to the present embodiment, the P funnel 2 is used to measure the muddy water flow time. Instead of such a P funnel 2, the Japan Society of Civil Engineers standard “PC grout” The J funnel 4 as shown in FIG. 6 and the like used in the “Joint fluidity test method (JSCE-F531-1994)” may be used. Further, a funnel having a shape different from that of the P funnel 2 and the J funnel 4 may be used. Alternatively, a container having a shape other than the funnel shape may be used instead of the P funnel 2 as long as a test similar to the flow-down method test using the P funnel can be performed.

  Further, in the method for adjusting the viscosity of the muddy water according to the present embodiment, the flow time of a constant weight of muddy water is measured by a flow method test using a P funnel. In the same way as above, by applying potential energy to the muddy water using gravity, the amount of resistance at the time of release of potential energy due to subsequent movement or deformation of such muddy water is replaced with time or length. This test method may be used instead of the flow-down type test by the P funnel.

  For example, as such other test methods, a slump flow test or a flow test by a cylinder method (the former Japan Highway Public Corporation Standard “Testing Method of Air Mortar and Air Milk (JHS A 313-1992)”), or A mortar flow test (a mortar flow test stipulated in the Japan Society of Civil Engineers standard "Cement physical test method (JIS R 5201-1981)") can be used.

  Here, the slump flow test described above is, as shown in FIG. 7, placing the slump cone 6 formed in a shape in which both upper and lower end faces are opened and gradually narrowed upward, on a horizontal plane, The slump cone 6 is filled with muddy water and stirred with a projecting rod, and then the slump cone 6 is gently pulled upward to measure the diameter of the muddy water spreading on the horizontal plane.

  Also, the flow test by the cylinder method is to place a cylindrical body with open end faces on a plate, fill the cylinder with muddy water, and then gently lift the cylindrical body upward. This is a test for measuring the maximum diameter of the muddy water spreading in the direction of the maximum diameter and the length of the diameter in the direction perpendicular to the direction of the maximum diameter and obtaining an average value of both.

  Further, in the mortar flow test, as shown in FIG. 8, a flow cone 8 having a predetermined shape, which is formed in a shape in which both upper and lower end surfaces are opened and gradually narrows upward, is placed on a table. After the muddy water is put into the flow cone 8 and stirred with the projecting rod, the flow cone 8 is gently lifted upward, and then the muddy water spreading on the table is given a predetermined number of times of vertical movement on the table. This is a test for measuring the length of the maximum diameter and the length of the diameter in the direction perpendicular to the direction of the maximum diameter, and obtaining an average value of both.

  When such a slump flow test, a flow test by the cylinder method, or a mortar flow test is used instead of the flow-down method test by the P funnel used in the method for adjusting the viscosity of the muddy water according to the present embodiment, Similar to the run-down mode test with a P funnel, a constant weight mud is used. Further, when a diagram corresponding to FIG. 1 is created by performing such a slump flow test, a flow test by a cylinder method, or a mortar flow test, the physical quantity on the vertical axis of such a diagram is Needless to say, it will be long.

It is a diagram used in the adjustment method of the viscosity of muddy water concerning one embodiment of the present invention, and is a diagram which shows the correlation between the amount of water in muddy water and the weight ratio of fine-grained soil, and the flow time. . It is a conceptual diagram which shows the structure of muddy water. The correlation between the muddy water density and the flow-down time is shown when the muddy water viscosity adjusting method according to the present embodiment is tested for the flow method using a P funnel and the muddy water viscosity test using a conventional P funnel. FIG. It is a conceptual diagram which shows the structure of muddy water. It is a conceptual diagram which shows the structure of muddy water. It is a side view which shows the J funnel used for the fluidity | liquidity test of PC grout. It is a side view which shows the slump cone 6 used for a slump flow test. It is a side view which shows the flow cone 8 used for a mortar flow test. It is side surface sectional drawing which shows the P funnel 2 used for the test of the viscosity of the muddy water by the conventional P funnel. It is a conceptual diagram which shows the structure of muddy water. It is a figure which shows the correlation of the density of a muddy water, and flowing-down time when the test of the viscosity of the muddy water by the conventional P funnel was done.

Explanation of symbols

2 P funnel 4 J funnel 6 Slump cone 8 Flow cone

Claims (2)

For each muddy water whose ratio of water content and fine soil weight is different from each other, we conducted a flow test to measure the flow time of a constant weight of muddy water. Create a correlation document by measuring the correlation between
For muddy water whose viscosity is unknown, the flow time is measured by the flow method test, and based on the correlation data, the ratio of the amount of water added to the flow time and the weight of fine-grained soil and the required viscosity are exhibited. A method for adjusting the viscosity of mud water, characterized by deriving and adjusting the amount of water to be increased or decreased from the relative ratio between the amount of water to be added and the ratio of the weight of fine-grained soil.   The method for adjusting the viscosity of muddy water according to claim 1, wherein the correlation material is created for each diameter of a discharge port of a funnel used in the flow-down method test.

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