JP2005187293A - Low heat-generating inner-filling material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low heat-generating inner-filling material which is excellent in strength development properties in the initial stage and is used for installing a cable; and to provide a low heat-generating inner-filling material which is excellent in strength development properties in the initial stage, generates a small amount of heat at the time of hardening, and is used for installing a cable. <P>SOLUTION: The low heat-generating inner-filling material is expressed by either of the following (1) and (2): (1) a low heat-generating inner-filling material containing a hardening accelerator, cement, a setting retarder, water, and 100-400 pts.wt. fine aggregate based on 100 pts.wt. the sum of the hardening accelerator and cement and (2) a low heat-generating inner-filling material belonging to (1) and containing the hardening accelerator in a content of 15-85 pts.wt. based on 100 pts.wt. cement. Preferably, the content of the setting retarder is 0.05-5 pts.wt. based on 100 pts.wt. the sum of the hardening accelerator and cement. Preferably, the content of water is 30-75 pts.wt. based on 100 pts.wt. the sum of the hardening accelerator and cement. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a low exothermic intermediate material mainly used for installation of cables such as communication cables and power cables, and in particular, a low exothermic intermediate material for installation of cables having excellent initial strength development and a small calorific value during curing. Regarding materials.

  In recent years, with the advancement of information technology, communication cables such as optical fiber cables and various telecommunication cables have been installed. When installing cables such as communication cables and power cables, pass the cable through the inner pipe of the double pipe consisting of the inner pipe and the outer pipe, and fill and harden the filling material between the inner pipe and the outer pipe. Has been done. Also, the cable may be installed by passing the cable through a single pipe and filling and curing the filling material in the pipe. A heat-sensitive material such as vinyl chloride resin may be used for the cable installation pipe or cable. In this case, there is a possibility that the temperature of the insert material becomes high due to the heat generated when the insert material is cured, and the tube and the cable are deformed or deteriorated by the heat. For this reason, the low exothermic intermediate | middle material with the small emitted-heat amount at the time of hardening is also proposed as an intermediate material (for example, patent document 1 and patent document 2).

However, these low exothermic intermediate materials have a small calorific value at the time of curing, but require a long time for curing, and have poor initial strength development. For this reason, it takes a long time to install the cable. When a cable is installed in an urban road, the road has to be closed for a long time, which causes a problem of causing traffic congestion for a long time.
JP-A-11-27841 JP 2000-281421 A

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a low exothermic intermediate material for cable installation that is excellent in initial strength development and has a small calorific value during curing.

That is, the present invention is a low exothermic intermediate material represented by the following (1) and (2).
(1) A low exothermic intermediate material containing 100 to 400 parts by weight of fine aggregate with respect to 100 parts by weight of a rapid hardening material, cement, a setting retarder, water, and a total of 100 parts by weight of the rapid hardening material and cement. (2) The low exothermic intermediate material according to (1), wherein the content of the rapid hardening material is 15 to 85 parts by weight with respect to 100 parts by weight of cement.

According to the present invention, it is possible to obtain a low exothermic intermediate material for cable installation that is excellent in initial strength development and has a small calorific value during curing. According to the present invention, it is possible to obtain a low exothermic intermediate material for cable installation having a compressive strength of 7.0 N / mm ² or more after 3 hours from water pouring and a temperature increase during curing of less than 40 ° C. Since the low exothermic intermediate material of the present invention is excellent in the initial strength development, the cable can be installed in a short time. In addition, since the low exothermic intermediate material of the present invention generates a small amount of heat during curing, the cable or / and the pipe line are less likely to be deformed or altered by the heat generated during curing.

  The low exothermic intermediate material of the present invention contains rapid hardwood, cement, setting retarder, water, and 100 to 400 parts by weight of fine aggregate with respect to 100 parts by weight of the total of the quickhard and cement. Features.

As a rapid hardening material used in the low exothermic intermediate material of the present invention, sodium carbonate, calcium chloride, water glass, nitrate, nitrite, alum including calcined alum, a setting accelerator such as aluminum oxide, aluminum hydroxide, Or calcium aluminate etc. are mentioned. Here, calcium aluminates are C ₃ A, C ₂ A, C ₁₂ when CaO is expressed as C, Al ₂ O ₃ as A, Na ₂ O as N, and Fe ₂ O ₃ as F. Calcium aluminate having a mineral composition expressed as A ₇ , C ₅ A ₃ , CA, C ₃ A ₅ , CA ₂ or the like, calcium aluminoferrite or calcium aluminate expressed as C ₂ AF or C ₄ AF or the like Calcium haloaluminates containing calcium fluoroaluminate, such as C ₃ A ₃ · CaF ₂ or C ₁₁ A ₇ · Caf _{2 in} which halogen is dissolved or substituted, C ₈ NA ₃ and C ₃ N ₂ A ₅ Calcium Sodium Aluminate, Calcium Lithium Aluminate, Alumina Cement, “Pacific Cement” (trade name) And manufactured by Sumitomo Osaka Cement Co., Ltd. "jet cement" ultra-fast hard cement (trade name), etc., as well as a generic term for calcium sulfoaluminate that appears when C _{3 A 3 ·} CaSO ₄ and the like. As the calcium aluminate, any of crystalline, non-crystalline, and mixed amorphous and crystalline materials can be used, and one or more of the calcium aluminates are used. It is possible. As the hardened material used in the present invention, calcium aluminate is preferable, and alumina cement is more preferable.

  The content of the quick-hardening material is 15 to 85 parts by weight with respect to 100 parts by weight of cement, and the initial compression strength of the low exothermic intermediate material is large, and the time during which the low exothermic intermediate material has fluidity is long. Therefore, it is preferable. More preferably, it is 29-70 weight part. When the amount is less than 15 parts by weight, the initial strength is low, and the strength may not be exhibited at the age of 3 hours. If the amount exceeds 85 parts by weight, the low exothermic intermediate material has a short fluidity, so there is a possibility that the low exothermic intermediate material cannot be filled in the cable installation pipe.

  As the cement used in the present invention, various portland cements such as normal, early strength, very early strength, low heat and moderate heat, ecocement, and these portland cement or ecocement include fly ash, blast furnace slag, silica fume or limestone fines. Examples include various mixed cements in which powders and the like are mixed, and these can be used alone or in combination of two or more. The cement here refers to a cement mainly composed of a rapid hardening component such as calcium aluminate, such as alumina cement, “Jet Cement” (trade name) manufactured by Taiheiyo Cement Co., Ltd., and “Jet Cement” (trade name) manufactured by Sumitomo Osaka Cement Co., Ltd. ) And the like are not included, and these are included in the rapid-hardening material. Since the low exothermic intermediate material has a long fluidity and high initial strength development, it is preferable to use ordinary Portland cement or early strength Portland cement or a mixture of ordinary Portland cement and early strength Portland cement as cement.

  The setting retarder used in the present invention is used for obtaining an appropriate pot life of the low exothermic intermediate material, and is particularly limited as long as it has a retarding action on the setting of the hydraulic substance. Rather, for example, organic acids such as citric acid, gluconic acid, malic acid and tartaric acid or salts thereof, sodium borate, sodium carbonate, lithium carbonate, potassium carbonate, sodium bicarbonate, lithium bicarbonate, potassium bicarbonate, etc. A salt, saccharides, etc. are mentioned, Among these, 1 type, or 2 or more types can be used. In particular, when one or more of citric acid, citrate, tartaric acid, tartrate, and alkali metal carbonate is used, the low exothermic intermediate material has a long fluidity and high initial strength development. Therefore, it is preferable.

  The content of the setting retarder is preferably 0.05 to 5 parts by weight with respect to 100 parts by weight as a total of the rapid hardening material and the cement. If it is less than 0.05 part by weight, the time during which the low exothermic intermediate material has fluidity is short. If it exceeds 5 parts by weight, the low exothermic intermediate material may not be cured. 0.1-3 weight part is more preferable.

  The water used in the present invention is not limited to tap water, although tap water is recommended. The water content is preferably 30 to 75 parts by weight with respect to a total of 100 parts by weight of the hardened material and cement. If it is less than 30 parts by weight, it is difficult to obtain the fluidity of the low exothermic intermediate material, and the fluidity time is short. If it exceeds 75 parts by weight, the strength of the cured product of the low exothermic intermediate material is lowered, which is not preferable. More preferably, it is 35 to 70 parts by weight with respect to 100 parts by weight of the total of the hardened material and cement.

  The low exothermic intermediate material of the present invention contains 100 to 400 parts by weight of fine aggregate with respect to 100 parts by weight of the total of the hardened material and cement. By including this amount of fine aggregate, the amount of temperature rise of the low exothermic intermediate material due to heat generation during curing is small, which is preferable. If the amount is less than 100 parts by weight, the amount of temperature rise is large, and there is a possibility that the cable or the cable mounting tube may be deformed or deteriorated due to heat generated when the low exothermic intermediate material is cured. If it exceeds 400 parts by weight, the fluidity of the low exothermic intermediate material cannot be obtained, or the compressive strength at the initial stage is small, which is not preferable. Preferably, since the amount of temperature rise is small and the initial compressive strength is high, the content of fine aggregate is set to 170 to 300 parts by weight with respect to 100 parts by weight of the total of the hardened material and cement.

  The fine aggregate used in the present invention is not particularly limited. For example, river sand, sea sand, mountain sand, crushed sand, artificial fine aggregate, slag fine aggregate, recycled fine aggregate, slag fine aggregate, etc. Although it is possible to use more than seeds, it is preferable to use a fine aggregate satisfying JIS A 5005 “Crumble for concrete and crushed sand” because of high initial strength development.

  The low exothermic intermediate material of the present invention includes one or more kinds of additives such as coarse aggregate, admixture and admixture, in addition to rapid hardening material, cement, fine aggregate, setting retarder and water. It can use together in the range which does not impair the effect of invention. As this additive, for example, a high-performance water reducing agent, a high-performance AE water reducing agent, a water reducing agent containing an AE water reducing agent and a fluidizing agent, a quick setting agent, a polymer for cement, a foaming agent, a foaming agent, a waterproofing agent, a rust prevention Agent, shrinkage reducing agent, thickener, water retention agent, pigment, fiber, water repellent, anti-whitening agent, antifoaming agent, river gravel, crushed stone, artificial coarse aggregate, slag coarse aggregate, recycled coarse aggregate, Examples include blast furnace slag fine powder, fly ash, stone powder, silica fume, and volcanic ash. In particular, if the thickener is contained in the low exothermic intermediate material of the present invention, it is difficult to cause material separation and bleeding water is hardly generated. Therefore, the low exothermic intermediate material of the present invention may contain a thickener. preferable. Since this effect is high when the thickener is cellulose ether, it is particularly preferable to contain cellulose ether in the low exothermic intermediate material of the present invention. When bleeding water is generated, a gap is formed between the cable installation tube and the cured low heat generating intermediate material of the present invention.

  The low exothermic intermediate material of the present invention is used by being filled in a cable installation pipe. This cable installation pipe may be a single pipe or a double pipe composed of an inner pipe and an outer pipe. A box with an open top may be used. The material of the pipe can be used without any particular limitation, and examples thereof include steel, concrete, cast iron, ceramics, resin, paper and the like. In the case of a double pipe, the low exothermic intermediate material of the present invention is usually filled between the inner pipe and the outer pipe. Further, the cable may be passed through a cable installation pipe, and the low heat-generating intermediate material of the present invention may be filled in the pipe to fix and protect the cable. By using the low exothermic intermediate material of the present invention, even when a heat-sensitive material such as vinyl chloride resin is used for the cable installation pipe or / and cable, the low exothermic intermediate material is cured. There is almost no possibility that the cable or the cable installation pipe is altered or deformed by the generated heat.

[Example 1]
The intermediate materials shown in Table 1 were prepared, and the fluidity retention time, the compressive strength at a material age of 3 hours, and the temperature increase were measured as a quality test of the intermediate materials. The results are shown in Table 2. The materials used at this time, the production method of the insert material, and the quality test method are shown below. Each insert in Table 1 was prepared by blending 1 part by weight of a water reducing agent and 0.02 parts by weight of a thickener with respect to a total of 100 parts by weight of the hardened material and cement.
<Materials used>
Rapid hardwood: Alumina cement (trade name “SECAL 51BT”, manufactured by Lafarge Aluminate)
Cement: Normal Portland cement (manufactured by Taiheiyo Cement)
Fine aggregate: Limestone crushed sand (coarse grain ratio; 2.80, specific gravity; 2.7)
Water: Tap water set retarder: A; Citric acid (commercially available reagent)
B: Mixture of 100 parts by weight of citric acid (commercial reagent) and 50 parts by weight of sodium carbonate (commercial reagent) Water-reducing agent: Naphthalene sulfonate-based high-performance water reducing agent (trade name “Mighty 100”, manufactured by Kao Corporation)
Thickener: Cellulose ether (manufactured by Shin-Etsu Chemical Co., Ltd.)
<Production method>
Water is put into a metal cylindrical can for mixing, and materials other than water that have been mixed in advance are added to 1100 r. p. m. Then, the mixture was put into the cylindrical can for 30 seconds while stirring with a hand mixer, and then further kneaded for 90 seconds to produce an intermediate material.
<Quality test method>
・ Measurement of fluidity retention time Transfer about 0.5 liters of the prepared intercalating material to a 1 liter poly beaker and leave it to stand. did. The test was carried out in a constant temperature room at 20 ° C. and 80% humidity.
-Compressive strength test According to the Japan Society of Civil Engineers standard JSCE-G 505 "Compressive strength test method of mortar or cement paste using cylindrical specimen", the compressive strength at a material age of 3 hours was measured. At this time, 3 hours after the start of contact between water and cement was defined as 3 hours of age.
・ Simple temperature rise test Place the prepared insert in a cylindrical container with a lid of 15 cm in diameter and 10 cm in height and measure the temperature at the approximate center of the insert in the container with a thermocouple. The difference between the maximum temperature and the temperature at the start of measurement was taken as the temperature rise.

From the results of Table 2, it can be seen that the low exothermic intermediate material of the present invention has a strength of 7.0 N / mm ² or more at a material age of 3 hours, so that the cable can be installed in a short time of 3 hours or less. Furthermore, the low exothermic intermediate material of the present invention had a low exothermic property with a temperature increase due to heat generation during curing being less than 40 ° C. In addition, the low exothermic intermediate material of the present invention in which the content of fine aggregate is 170 to 350 parts by weight with respect to 100 parts by weight of the rapid hardening material and cement is 30 ° C. due to heat generation during hardening. Therefore, it can be suitably used for installation of a cable using a low heat-resistant material such as vinyl chloride resin or a cable using a cable installation pipe. In addition, in material age 3 hours, mixing | blending No. The inserts 16 and 18 were uncured. In addition, blending No. No. 17 intermediate material lost fluidity before kneading.

[Example 2]
A double pipe consisting of a paper outer tube having an inner diameter of 200 mm, a height of 1000 mm, and a thickness of 4.5 mm, and an inner tube made of a vinyl chloride resin having an inner diameter of 100 mm, a height of 1000 mm, and a thickness of 6.6 mm is set up vertically. Through an electric cord coated with a vinyl chloride resin, the formulation No. used in Example 1 was passed. 5, 11, 12, 15 and 16 inserts were filled between the inner and outer tubes. The amount of temperature rise (difference between the maximum temperature and the temperature at the start of measurement) at the interface between the inner pipe having a height of 500 mm and the insert was measured. In addition, the presence or absence of alteration or deformation of the cable or the cable installation tube was confirmed visually and touched with a finger. Furthermore, the presence or absence of the curing of the intermediate material after 3 hours from the start of contact between water and cement was confirmed by touching the surface of the intermediate material with a finger. The test results are shown in Table 3. The test was carried out in a constant temperature room at 20 ° C. and 80% humidity.

  From the test results of Table 3, the low exothermic intermediate materials (Formulation Nos. 5, 11 and 12) of the present invention were cured after 3 hours from the start of contact between water and cement. Sixteen interstitial materials were uncured 3 hours after the start of contact between water and cement. In addition, in the case of using the low exothermic intermediate material of the present invention, the temperature increase at the interface between the inner tube and the low exothermic intermediate material during curing was less than 30 ° C., so the cable or the cable installation tube was altered. Or, the cable could be installed in a short time without deformation. In contrast, formulation No. The inner pipes for cable installation made of vinyl chloride resin were softened due to the heat generated at the time of curing using the 15 and 16 inserts.

  By using the low exothermic intermediate material of the present invention, it is possible to shorten the construction time required for cable installation of communication cables, power cables, etc., regardless of the material of the cable and cable installation pipe, compared to the conventional one. became. In particular, when installing cables embedded in urban roads, the use of the low exothermic intermediate material of the present invention can shorten the time for closing the road as compared to the conventional method, and the cables and cable installation pipes are hardened. It is also possible to install the cable without being deformed or altered by the heat generation.

Claims (2)

A low exothermic intermediate material containing 100 to 400 parts by weight of fine aggregate with respect to a rapid hardening material, cement, a setting retarder, water, and a total of 100 parts by weight of the rapid hardening material and cement. The low exothermic intermediate material according to claim 1, wherein the content of the quick-hardening material is 15 to 85 parts by weight with respect to 100 parts by weight of cement.