JP3696491B2 - Low thermal resistance type slurry mortar and its stock solution - Google Patents

Description

【００２１】
上記の試験結果から明らかなように、比較例１にあっては、そのスラリーモルタル並びに原液の比重が何れも小さく、熱抵抗値についても、１００℃・cm／Ｗを大きく上回るものであったのに対して、実施例１及び２にあっては、熱抵抗値が約８０℃・cm／Ｗ前後の値を示すものが得られたものである。しかも、この実施例１及び２の流動性は、前述のように、フロー試験（ＪＨＳ Ａ３１３）の値が２７５mm、１９５mmであり、ケーシングの埋め戻し用のスラリーモルタルとして使用し得るものである。
【００２２】
【発明の効果】
以上、本願の請求項１及び２の発明にあっては、資源の有効活用に有利な汚泥スラリーを用いたスラリーモルタルにあって、適度な流動性と熱抵抗値の低減化という、両立困難な課題を解決すことができ、ケーブル埋め戻し用として最適な低熱抵抗型のスラリーモルタルを提供することができたものである。
また、本願の請求項３及び４の発明にあっては、上記のケーブル埋め戻し用として最適な低熱抵抗型のスラリーモルタルを容易に製造することのできるスラリーモルタル用の原液を提供することができたものである。
特に、汚泥スラリーから得た砂を１．０mm以下、望ましくは０．５mm以下の粒子径の粒度に調整して用いることにより、原液の全成分を建設現場等から排出される汚泥スラリーから得ることができ、資源のリサイクルを図ることができるものである。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to improvement of a low heat resistance type slurry mortar and its stock solution.
[0002]
[Prior art]
Today, cables such as power transmission lines and communication lines are often buried in the ground. These cables are laid in buried pipes such as tunnels and fume pipes and then backfilled with mortar for backfilling. More specifically, a large number of electric pipes are arranged in the fume pipes, and a mortar for backfilling is filled in the space between the electric pipes in a state where cables such as transmission lines are inserted into the electric pipes. It will be backfilled. At that time, from the viewpoint of streamlining construction, one construction section tends to be long, and today, from about 100 m section to 600 m section is backfilled at once. Yes. The method is to arrange a plurality of mortar pressure feeding pipes with different inner diameters of about 75 mm, for example, 500 m, 400 m, 300 m from the base end of the construction section to the base end of the mortar pressure feeding pipe. The mortar for backfilling is pumped with a pump so that the entire section is backfilled substantially uniformly. Therefore, moderate fluidity is required for the backfill mortar so that it can be pumped over a long distance and spreads uniformly at the pumping destination.
[0003]
On the other hand, in the case of a mortar for backfilling, in the case of a cable, particularly a transmission line, it is desired to reduce the thermal resistance value of the backfilled mortar from the viewpoint of power transmission efficiency. This thermal resistance value tends to decrease as the specific gravity of the mortar increases. Therefore, in the case of the most common mortar, which is a mixture of cement, sand as aggregate, and water, it is conceivable to increase the amount of aggregate to a high specific gravity. If it is going to answer the request | requirement of reduction of thermal resistance, fluidity | liquidity will fall. When the fluidity is lowered, there is a problem that long-distance pumping is difficult and backfilling cannot be performed completely, leaving a large space.
[0004]
In addition, a proposal has been made to promote effective utilization of resources by utilizing sludge slurry discharged by tunnel excavation or the like as a raw material for this type of backfill (Japanese Patent Laid-Open No. 11-285697). In this proposal, sludge slurry is blended with at least one member of the group consisting of refined earth (bentonite), water, thickener (sodium carboxymethylcellulose), and peptizer, and the specific gravity is 1.090 to 1.145 g. The slurry mortar is obtained by mixing a slurry stock solution adjusted to have a viscosity of 20.5 to 26.0 seconds with a viscosity of 2 cm to 26.0 seconds.
However, if the specific gravity of the undiluted solution is 1.090 to 1.145 g / cm 3, the above-mentioned thermal resistance value exceeds 130 ° C. · cm / W, so that we can answer the demand for reduction of the thermal resistance value. I can't.
[0005]
[Problems to be solved by the invention]
In this way, mortar for backfilling cables such as power transmission lines needs to satisfy the difficult requirements of both moderate fluidity and reduced thermal resistance, but these requirements are satisfied. The mortar to be used has not been developed yet. Therefore, the present invention is intended to provide a low thermal resistance type slurry mortar and its undiluted solution that can achieve both appropriate fluidity and reduction in thermal resistance value.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the inventor of the present application tried to improve the mortar using the sludge slurry, which is advantageous from the viewpoint of effective use of resources, as a starting point. Specifically, we tried to increase the specific gravity and reduce the heat resistance value by blending sand with a higher specific gravity than sludge slurry, but in normal sand, as described above, the fluidity is low. Could not solve the problem of lowering. Therefore, as a result of diligent research, it is possible to increase the specific gravity and reduce the thermal resistance value and to prevent the decrease in fluidity by blending the finely divided aggregate into the sludge slurry. Based on this knowledge, the present invention has been completed.
[0007]
In the invention of claim 1 of the present application, an aggregate having a particle diameter of 1.0 mm or less is blended in the sludge slurry, the specific gravity is set to 1.3 g / cm 3 or more, and the value of the flow test (JHS A313) is set to 240 mm or more. A mortar in which a stock solution for slurry mortar and a solidifying agent such as cement are mixed, the specific gravity of this mortar is 1.54 g / cm 3 or more, the value of the flow test (JHS A313) is 190 mm or more, and curing is solidified. The above problem is solved by providing a low thermal resistance type slurry mortar characterized by a later thermal resistance value of less than 100 ° C. · cm / W.
In addition, the heat resistance value after hardening solidification means the heat resistance value of the slurry mortar which passed through the curing period of 28 days after pouring.
The invention of claim 2 of the present application is a stock solution 1 m3 for slurry mortar comprising a sludge slurry designed to have a specific gravity of 1.4 to 2.0 g / cm @ 3 and a flow test (JHSA 313) value of 300 to 500 mm, cement, etc. A slurry mortar containing 100 to 250 kg of a solidifying agent having a specific gravity of 1.54 g / cm 3 or more, a flow test (JHS A313) value of 190 mm or more, and a heat resistance value after curing and curing The above-mentioned problems are solved by providing a low heat resistance type slurry mortar characterized by having a low temperature of less than 90 ° C. · cm / W.
In the invention of claim 3 of the present application, an aggregate having a particle size of 1.0 mm or less and higher specific gravity than the sludge slurry is blended in the sludge slurry, the specific gravity is 1.3 g / cm 3 or more, and the flow test (JHS A313) The above problem is solved by providing a stock solution for slurry mortar characterized in that the value is designed to be 240 mm or more.
The invention of claim 4 of the present application is the undiluted solution for slurry mortar according to the invention of claim 3, wherein the sludge slurry is mixed with sand having a particle diameter of 0.5 mm or less as an aggregate, and the specific gravity is 1.4 to It provides what is characterized by being designed at 2.0 g / cm @ 3.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Sludge sludge is discharged from excavation sites, etc., and its specific gravity and fluidity vary. To produce low heat resistance type slurry mortar using this, sludge slurry is used for slurry mortar designed to an appropriate value. A stock solution of
First, the thermal resistance of the slurry mortar is considered to have a correlation with the specific gravity of the mortar, and in order to obtain a low thermal resistance type slurry mortar, the specific gravity of the stock solution for the slurry mortar is set to 1.3 g / cm 3 or more. Preferably, it is 1.4 to 2.0 g / cm @ 3. If this specific gravity is too low, the desired low thermal resistance type slurry mortar cannot be obtained. On the other hand, if the specific gravity is too high, the fluidity of the resulting slurry mortar decreases, and the backfilling operation cannot be performed completely.
In order to obtain the fluidity desired for this backfilling operation, the fluidity of the stock solution for slurry mortar is designed so that the value of the flow test (JHS A313) is 240 mm or more, more preferably 300 to 500 mm. If the fluidity (the value of the flow test (JHS A313)) is small, long-distance pumping becomes difficult, and the slurry mortar may not spread over the entire area during backfilling. On the contrary, although it is not necessary to restrict | limit about the upper limit of fluidity | liquidity, if fluidity | liquidity becomes high, there exists a possibility that specific gravity may fall, From this viewpoint, 500 mm or less is suitable.
[0009]
The sludge slurry is generated as construction sludge, and the conditions are not uniform depending on the conditions of the excavation site to be discharged, but are often smaller than the above-mentioned specific gravity. Therefore, it is necessary to mix | blend aggregate and to raise the specific gravity. At that time, when an aggregate such as normal sand is blended, the specific gravity can be increased, but the fluidity is lowered. Therefore, in the present invention, an aggregate having a particle diameter of 1.0 mm or less, more preferably 0.5 mm or less is blended.
As long as the type of aggregate has a higher specific gravity than the sludge slurry and can meet the above particle diameter conditions, it can be variously modified. A relatively uniform one is used so as to meet the above. In particular, it is advantageous from the viewpoint of resource recycling by filtering sand having a particle diameter of 1.0 mm or less, preferably 0.5 mm or less from the sludge slurry, and using this sand as an aggregate. The aggregate may be mixed with particles other than sand. Examples of the other aggregates include pulverized ceramics and bentonite, and fly ash, incinerated ash, and the like can also be added.
Desirably, if a sludge slurry having a specific gravity of 1.05 to 1.25 g / cm 3 (more preferably 1.1 to 1.2 g / cm 3) is used, a specific gravity of 2 or more and a particle diameter of 0.5 mm or less may be used. By blending sand, a stock solution for slurry mortar having a specific gravity of 1.4 to 2.0 g / cm 3 flow test (JHS A313) of 240 mm or more, desirably 300 to 500 mm can be obtained.
[0010]
Conversely, when the specific gravity of the sludge slurry is large or the fluidity becomes too small, water can be added. And if you want to fine-tune the fluidity of the resulting undiluted solution, add a thickener such as sodium carboxymethylcellulose, or conversely, repel the particles by the charging effect of the peptizer (eg trademark Brook) Or a peptizer to be dispersed) may be added to improve fluidity.
[0011]
The slurry mortar stock solution designed as described above is kneaded with a solidifying agent such as cement to complete the slurry mortar.
As the cement, Portland cement, blast furnace cement or the like can be used, and an auxiliary agent such as a fluidizing agent may be added as necessary.
[0012]
The blending amount of the slurry mortar stock solution and the solidifying agent such as cement is desirably 100 to 250 kg of the solidifying agent such as cement with respect to 1 m3 of the slurry mortar stock solution.
The fluidity of the obtained slurry mortar is such that the value of the flow test (JHS A313) is 190 mm or more, more preferably 240 mm or more. The upper limit is not particularly limited, but when the aggregate is the above sand, it is considered that the upper limit is about 600 mm. If the value of the flow test (JHS A313) is 190 mm or more, it can sufficiently cope with backfilling of a section of about 100 m, and if it is 240 mm or more, it can also support backfilling of a section other than 500 m.
The specific gravity of the slurry mortar is 1.54 g / cm 3 or more, and the heat resistance value after curing and solidifying the slurry mortar is less than 100 ° C. · cm / W. More desirably, it is less than 96 ° C. · cm / W, and more desirably less than 90 ° C. · cm / W. Thus, by realizing a low thermal resistance value, it is possible to prevent a reduction in power transmission efficiency of the backfilled transmission line.
[0013]
【Example】
Hereinafter, in order to enhance the understanding of the present invention, examples and comparative examples will be shown. However, the present invention should not be understood to be limited to these examples.
[0014]
Example 1
For slurry mortar with a specific gravity of 1.50 g / cm3 and sand with a specific gravity of 2.13 and a particle size of 0.5 mm or less in a sludge slurry with a specific gravity of 1.22 g / cm3 and a flow test (JHS A313) value of 580 mm A stock solution of was obtained. As for the fluidity of this stock solution, the value of the flow test (JHS A313) was 440 mm.
200 mg of Portland cement was mixed with 1 m3 of this stock solution and kneaded with a mortar mixer to obtain a slurry mortar with a specific gravity of 1.58 g / cm3. As for the fluidity of this slurry mortar, the value of the flow test (JHS A313) was 275 mm.
[0015]
Example 2
For slurry mortar with a specific gravity of 1.65 g / cm3 and sand with a specific gravity of 2.13 and a particle diameter of 0.5 mm or less in a sludge slurry with a specific gravity of 1.22 g / cm3 and a flow test (JHS A313) value of 580 mm A stock solution of was obtained. As for the fluidity of this stock solution, the value of the flow test (JHS A313) was 340 mm.
200 kg of Portland cement was mixed with 1 m3 of this stock solution and kneaded with a mortar mixer to obtain a slurry mortar with a specific gravity of 1.89 g / cm3. As for the fluidity of this slurry mortar, the value of the flow test (JHS A313) was 195 mm.
[0016]
Comparative Example 1
Sludge slurry having a specific gravity of 1.22 g / cm3 and a flow test (JHS A313) value of 580 mm was used as a stock solution for slurry mortar, and 200 kg of Portland cement was blended with 1 m3 of this stock solution and kneaded with a mortar mixer. A 37 g / cm @ 3 slurry mortar was obtained. As for the fluidity of this slurry mortar, the value of the flow test (JHS A313) was 300 mm.
[0017]
Test of Thermal Resistance Values The slurry resistance mortars of Examples 1 and 2 and Comparative Example 1 were tested for thermal resistance values.
[0018]
(1) Preparation of specimens The slurry mortars of Examples 1 and 2 and Comparative Example 1 were poured into a mold having an inner size of 26 cm × 26 cm × 7.5 cm, allowed to stand and cured. The curing conditions were a 20 ° C constant temperature room sealed curing, and the upper surface was leveled 3 days after standing. The curing period was 28 days.
[0019]
(2) Measurement of thermal resistance value (a) The atmosphere on the upper surface side of the theoretical specimen is kept at room temperature (20 ° C.), the atmosphere on the lower surface side is kept at a high temperature (50 ° C.), and the temperature of the lower surface (t2) and upper surface (t1) The thermal conductivity (K) was determined by measuring the difference (t) and the heat flow rate (Q) from the lower surface to the upper surface. The thermal resistance value is determined by the reciprocal of thermal conductivity (1 / K).
K = Q / (t / h)
K: Thermal conductivity (W / ° C · cm)
Q: Heat flow (W / m2)
t: Temperature difference between upper surface and lower surface (° C.) t = t2−t1
h: Distance between upper surface and lower surface (specimen thickness) h = 0.075 m
(B) Equipment used: High-temperature steam curing tank (set temperature 55 ° C)
Upper and lower surface temperature measurements: Thermocouple installed on the upper surface before the test, lower surface on the instrument (TDS-303; Tokyo Sokki Co., Ltd.) ).
Measurement of heat flow rate: Measured with a heat flow meter (HFM-115; Kyoto Electronics Industry).
(C) Test procedure 1) The test was conducted when 28 days had passed after pouring. On the day before the test, each specimen was placed in a steam curing tank and heated.
2) The test was started after confirming that the upper and lower surface temperatures showed steady values and confirmed that they were steady.
3) A heat flow meter sensor was installed on the upper surface of the specimen and left for about 10 minutes until the heat flow meter was stabilized.
4) Data was recorded at 1 minute intervals per measurement.
5) Three data were recorded for each specimen (9 times for each formulation).
(3) Test results Table 1 shows the test results.
[0020]
[Table 1]

[0021]
As is clear from the above test results, in Comparative Example 1, the specific gravity of the slurry mortar and the stock solution was both small, and the thermal resistance value was much higher than 100 ° C. · cm / W. On the other hand, in Examples 1 and 2, a thermal resistance value of about 80 ° C. · cm / W was obtained. Moreover, as described above, the fluidity of Examples 1 and 2 has a flow test (JHS A313) value of 275 mm and 195 mm, and can be used as a slurry mortar for backfilling the casing.
[0022]
【The invention's effect】
As described above, in the inventions of claims 1 and 2 of the present application, in the slurry mortar using the sludge slurry that is advantageous for effective utilization of resources, it is difficult to achieve both the appropriate fluidity and the reduction of the thermal resistance value. The problem could be solved and a low heat resistance type slurry mortar optimum for cable backfilling could be provided.
Further, according to the inventions of claims 3 and 4 of the present application, it is possible to provide a stock solution for slurry mortar that can easily produce an optimum low heat resistance type slurry mortar for use in cable backfilling. It is a thing.
In particular, by using the sand obtained from the sludge slurry adjusted to a particle size of 1.0 mm or less, preferably 0.5 mm or less, all components of the stock solution are obtained from the sludge slurry discharged from the construction site or the like. It is possible to recycle resources.

Claims (4)

Aggregate with a particle diameter of 1.0 mm or less is mixed with sludge slurry, and the specific gravity is 1.3 g / cm3 or more, and the flow test (JHS A313) value is 240 mm or more, and a stock solution for slurry mortar, cement, etc. The specific gravity of this mortar is 1.54 g / cm 3 or more, the value of the flow test (JHS A313) is 190 mm or more, and the heat resistance value after curing is 100 ° C. A low thermal resistance type slurry mortar characterized by being less than cm / W. 1 m3 of a stock solution for slurry mortar composed of sludge slurry designed to have a specific gravity of 1.4 to 2.0 g / cm3 and a flow test (JHS A313) value of 300 to 500 mm, and 100 to 250 kg of a solidifying agent such as cement A blended slurry mortar,
This slurry mortar has a specific gravity of 1.54 g / cm 3 or more, a flow test (JHS A313) value of 190 mm or more, and a heat resistance value after curing and curing of less than 90 ° C. · cm / W. Resistance type slurry mortar. The sludge slurry is designed to be blended with aggregates with a particle size of 1.0 mm or less and higher specific gravity than the sludge slurry, with a specific gravity of 1.3 g / cm 3 or more and a flow test (JHSA 313) value of 240 mm or more. Feature stock solution for slurry mortar. 4. The undiluted solution for slurry mortar according to claim 3, wherein sand having a particle diameter of 0.5 mm or less is blended in the sludge slurry as an aggregate and the specific gravity is designed to be 1.4 to 2.0 g / cm <3>.