JP2006037611A - Polymer cement mortar manhole - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polymer cement mortar manhole having superior tensile performance and bending performance to a concrete manhole, lighter weight and durability. <P>SOLUTION: A polymer cement mortar manhole member is formed of Portland cement, a fine aggregate, polymer emulsion, a high performance water reducing admixture, and an antifoaming agent: the cement of 100 pts.mass, the fine aggregate of 100-200 pts.mass, the polymer emulsion of 5-22 pts.mass in terms of solid component (effective component), the high performance water reducing admixture of 1-3 pts.mass, the antifoaming agent of 0.2-2 pts.mass, and water of 16-25 pts.mass. The members are bound one another to with an adhesive to form the large polymer mortar manhole. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a manhole for relaying / branching a power cable, an information communication cable, an optical fiber cable and the like buried in the ground.

When constructing cables such as power cables, communication cables, and optical fibers in the ground, box-type manholes and handholes that relay cables and serve as laying operations and inspection grooves are provided at relay points at appropriate intervals. These manholes and handholes are usually composed of a box-shaped container having an opening at the upper end, a lid for closing the opening, a pipe-shaped socket, and the like.
These manholes and handholes are made of concrete or plastic with excellent formability because they require the required amount of through holes with excellent dimensional accuracy to penetrate the side wall and guide the cable into the box. Used to increase productivity.

  Plastic manholes and handholes are made of reinforced plastic (FRP) made of thermosetting synthetic resin and glass fiber, and are lightweight and excellent in heat resistance and impact resistance.

  Concrete manholes and handholes are relatively inexpensive and superior in durability and fire resistance compared to plastics, but on the other hand, they have disadvantages that the weight of the members is large and difficult to handle, and cracks are likely to occur. In particular, from the standpoint of concrete bending strength and shear strength, the cross-section of the member has to be increased to some extent, and the product weight inevitably increases. For large manholes, large mechanical forces are used for transportation and construction. Have the disadvantages you have to do. Moreover, although concrete is excellent in durability, for example, even if measures against frost damage are taken in cold regions, problems remain in long-term use such as occurrence of peeling due to freezing and thawing.

  Furthermore, since concrete manholes are manufactured by binding concrete manhole members with joints, bolts, or the like, it is necessary to take measures to prevent water leakage.

Resin concrete products have been developed in order to solve the disadvantages derived from the concrete products as described above.
Resin concrete is a combination of aggregate and filler with a resin such as unsaturated polyester resin, epoxy resin, or acrylic resin as a binder. Compared with cement concrete using cement as a binder, The strength, bending strength, compressive strength, etc. are large, and it is excellent in that it has chemical resistance and is lightweight.
However, there are problems such as low possibility and high price. As a method for improving the flexibility, a resin concrete pipe technique using a fiber reinforcing material (see, for example, Patent Document 1) has been proposed.

In addition, in concrete manholes, technology that imparts ultra-high strength properties, high toughness, impact resistance, and high durability while retaining the properties of concrete such as relatively low cost, durability and fire resistance. Has been proposed (for example, see Patent Document 2).
JP 2002-293599 A JP 2001-218349 A

  However, in order to produce resin concrete products, dry aggregate is used (it will reduce strength if not used in a dry condition), so a storage silo dedicated to dry aggregate is necessary, and aggregate management is complicated. The weighing operation is dangerous and complicated due to the use of a variety of resin materials including synthetic resin, which is a hazardous material, and heat curing is required depending on the application, and special equipment is required (steam curing cannot be used), etc. The problem still exists.

The present invention has been made in view of the problems of the prior art of concrete manholes and handholes described above, is superior in tensile performance and bending performance than concrete manholes and handholes, is lightweight and inexpensive, and It is an object of the present invention to provide a manhole made of polymer cement mortar having a good water-stopping property.
Since the handhole is smaller than the manhole, the handhole is also included in the manhole in the present application.

  As a result of intensive studies to solve the above problems, the present inventors have superior tensile performance and bending performance than concrete manholes by combining cement, fine aggregate, polymer emulsion, water reducing agent and antifoaming agent. The present invention was completed by developing a manhole member made of polymer cement mortar that is lightweight and has good water-stopping properties, and that it can be produced through steam curing.

That is, the present invention is a manhole made of polymer cement mortar, characterized by comprising Portland cement, an aggregate composed only of fine aggregate, a polymer emulsion, a high-performance water reducing agent, and an antifoaming agent (Claim 1). .
The water cement ratio is 25% or less, and the manhole made of polymer cement mortar according to claim 1 (claim 2).
3. The polymer cement mortar manhole according to claim 1, further comprising at least one powder selected from blast furnace slag powder, fly ash, silica fume, limestone powder and silica stone powder. (Claim 3).
4. The polymer cement mortar manhole according to claim 1, 2, or 3, wherein the polymer emulsion is a poly (meth) acrylic acid ester-based water-soluble polymer (claim 4).
The Portland cement is a high-strength Portland cement, and the polymer cement mortar manhole according to claim 1, 2, 3, and 4 (Claim 5).

The manhole made of polymer cement mortar according to the present invention can be produced by the following method.
That is, the polymer cement mortar manhole member of the present invention is composed of 100 parts by mass of cement, 100 to 200 parts by mass of fine aggregate, 5 to 22 parts by mass of polymer emulsion in terms of solid content (active ingredient), and a water reducing agent. 1 to 3 parts by mass, 0.2 to 2 parts by mass of an antifoaming agent, and 16 to 25 parts by mass of water.
Further, the present invention is characterized in that a large manhole made of polymer cement mortar is produced by binding the manhole members made of polymer cement mortar with an adhesive.

  According to the present invention, it is possible to provide a lightweight manhole that is superior in tensile performance, bending performance, water stopping performance, and durability to a concrete manhole. In addition, unlike storage manholes, storage silos dedicated to dry aggregates and heat curing equipment are not required, and it is not necessary to use a wide variety of resin materials including synthetic resins that are dangerous.

  Hereinafter, the polymer cement mortar manhole of the present invention and the manufacturing method thereof will be described.

  The binder used in the present invention may be a hydraulic binder, and may be any of ordinary Portland cement, early-strength Portland cement, mixed cement, ecocement, special cement, etc., but ordinary Portland cement, early-strength Portland cement In the case of air curing, ordinary Portland cement and early-strength Portland cement are particularly preferable, and in the case of steam curing, early-strength Portland cement is particularly preferable.

Aggregates used in the present invention are only fine aggregates. The fine aggregate is not particularly limited as long as it is a fine aggregate usually used in concrete products. For example, land sand produced in Ogasa, Shizuoka Prefecture (surface dry density 2.60 g / cm ³ ) is exemplified.

As the polymer emulsion in the present invention, an acrylic emulsion and an acryl-styrene emulsion are preferable in view of bending strength, and an acrylic emulsion is more preferable.
The acrylic emulsion can be obtained by emulsion polymerization of a monomer composition containing one or more monomers selected from (meth) acrylic acid ester monomers. As the (meth) acrylic acid ester monomer, butyl acrylate, 2-ethylhexyl acrylate, and methyl methacrylate are preferable.
The preferable particle diameter of the polymer emulsion in the present invention is 50 to 400 nm, more preferably 100 to 200 nm.
Moreover, as solid content of the polymer emulsion in this invention, it is preferable that it is 30-70 mass%, More preferably, it is 45-70 mass%.
Furthermore, the viscosity of the polymer emulsion in the present invention is preferably 200 mPa · s or less, and more preferably 100 mPa · s or less.

If the solid content is less than 30% by mass, the amount of water contained in the polymer emulsion and the amount of surface water adhering to the fine aggregate may exceed the unit water amount of the polymer cement mortar, which is not practical. When the particle diameter is 400 nm or more, the filling effect between the cement particles and the ball bearing effect are reduced, so that it is not applied from the viewpoint of producing the high-strength polymer cement mortar which is the object of the present invention. When the viscosity is 200 mPa · s or more, the kneaded polymer cement mortar has a high viscosity, and the filling effect on the mold is deteriorated, and a uniform concrete product cannot be obtained.

5-22 mass parts is preferable in conversion of solid content (active ingredient) with respect to 100 mass parts of cement, and, as for the compounding quantity of a polymer emulsion, 8-14 mass parts is more preferable. When the blending amount of the polymer emulsion is less than 5 parts by mass in terms of solid content (active ingredient) with respect to 100 parts by mass of cement, the fluidity is lowered and the bending strength is lowered, which is not preferable. On the other hand, when the blending amount of the polymer emulsion exceeds 22 parts by mass in terms of solid content (active ingredient) with respect to 100 parts by mass of cement, the amount of the hardened cement occupies more than the increase in bending strength due to the reinforcing effect of the polymer. Since the decrease in the bending strength due to the decrease becomes larger, the bending strength as the polymer cement mortar composite starts to decrease.

  As the high-performance water reducing agent in the present invention, any high-performance water reducing agent that is not an AE usually used for concrete may be used, but a high water reducing effect is desirable. For example, a polycarboxylic acid ether type high performance water reducing agent is exemplified.

  Examples of antifoaming agents in the present invention include silicone emulsions and special nonionic surfactants. In general, mixing a polymer emulsion for cement admixture into cement mortar will cause significant foaming and air entrainment more than necessary, so it is necessary to add an appropriate antifoaming agent to produce a dense hardened polymer cement mortar. There is. As a method of adding the antifoaming agent, it may be added in advance during the production of the polymer emulsion, may not be added during the production of the polymer emulsion, and may be added during the mixing of the polymer cement mortar. It can be added and further added when kneading the polymer cement mortar.

As for the compounding quantity of an antifoamer, 0.2-2 mass parts is preferable with respect to 100 mass parts of cement. If the blending amount of the antifoaming agent is less than 0.2 parts by mass with respect to 100 parts by mass of the cement, the entrained bubbles in the polymer cement mortar cannot be sufficiently erased, and as a result, the bending strength is lowered. On the other hand, when the blending amount of the antifoaming agent is 2 parts by mass or more with respect to 100 parts by mass of cement, since most of the entrained bubbles have already been erased, there is not much effect and it becomes uneconomical.

  In addition, the adhesive used for adhering the members of polymer cement mortar manholes is not particularly limited as long as it is usually used for adhering concrete members to each other, particularly preferably epoxy. Resin adhesive is good. For example, Epobond EP-3 (trade name, manufactured by Aoi Chemical Industries), EP40 (trade name, manufactured by Cemedine), Showbond # 101 (trade name, manufactured by Showbond Construction), Bond Top WG (trade name, manufactured by Aoi Chemical Industries) ) And the like are exemplified.

  When adhering the members of the polymer cement mortar manhole of the present invention, sufficient adhesion strength can be ensured without using a primer, but when using a primer, it is not particularly limited, What is necessary is just to be used for the primer process at the time of adhesion | attachment of concrete members normally. For example, a primer exclusively for an epoxy resin adhesive is exemplified.

Next, the composition of the present invention will be described.
The cement is 630-1070 kg / m ³ .
The fine aggregate is 1070 to 1260 kg / m ³ .
The polymer emulsion is 60 to 140 kg / m ³ in terms of solid content (active ingredient).
The water reducing agent is 5 to 20 kg / m ³ .
The defoamer is ³ to 14 kg / m ³ .
The water is 150-190 kg / m ³ (however, including the water in the polymer emulsion, superplasticizer and antifoam).

Next, a manufacturing method will be described.
The manufacturing method is not particularly limited, and may be in accordance with a method for manufacturing a normal concrete manhole.
That is, each material is weighed so that the above composition is obtained, and first, cement and fine aggregate are put into a mixer and stirred (empty kneading), and further, a polymer emulsion, water, a water reducing agent and an antifoaming agent are added and kneaded. . Then, the kneaded product is filled into a predetermined mold having reinforcing bars arranged in the mold, and either vibration-free compaction, vibration compaction, or pressure vibration compaction is performed depending on the fresh properties of the kneaded product. After curing, the mold is removed and a manhole member made of polymer cement mortar is produced.
As a method of steam curing, a normal method may be followed. For example, a method of holding for 2 hours at a preheating, a heating rate of 20 ° C./hour, holding at 65 ° C. for 3 hours, and then naturally cooling is exemplified.
The polymer cement mortar manhole member according to the present invention can be cured by a curing method other than steam curing, but steam curing is preferable. In particular, when the hydraulic binder is early-strength Portland cement, steam curing is more preferable.

Next, after subjecting the bonding surfaces of the members to a disk grinder treatment or a primer treatment, the members are bonded together with an adhesive, and after curing, a manhole made of polymer cement mortar used in the present invention can be produced.
In addition, when manufacturing a small manhole, that is, a handhole, a member for a handhole made of polymer cement mortar may be manufactured, and the handhole may be directly manufactured without binding and integrating the members. good.

Manufacture of polymer cement mortar manholes and polymer cement mortar manholes will be described.
Cement: Hayashi Portland cement Fine aggregate: Land sand from Hamaoka-cho, Ogasa-gun, Shizuoka (surface dry density 2.60 g / cm ³ , FM 2.75)
Polymer emulsion: poly (meth) acrylic acid ester (solid content 50%)
High-performance water-reducing agent: Polycarboxylic acid ether-based high-performance water-reducing agent Antifoaming agent: Special nonionic surfactant Water: Tap water Rebar: Steel bar

Formulation (kg / m ³ ) and production 801 kg of early strength Portland cement, 1202 kg of fine aggregate (land sand), 176 kg of polymer emulsion, 17.6 kg of water reducing agent, 5.3 kg of antifoaming agent, 53 kg of water, 2 in a volume of 2 cubic meters The mixture was kneaded with an axial mixer at a mixing amount of 1 cubic meter, filled into a predetermined mold with a reinforcing bar, and finely compacted with a mold vibrator to form.
Thereafter, steam curing was performed. The conditions were 20 ° C. for 2 hours, the temperature was raised at 20 ° C./hour, the temperature was kept at 65 ° C. for 3 hours, and then allowed to cool naturally.
After completion of the steam curing, the mold was removed to produce a manhole member made of polymer cement mortar.
Next, after wiping off the oil and the like with acetone on the bonding surface between the members, the members are bonded with a putty-like two-component epoxy resin adhesive, and after curing, the manhole made of polymer cement mortar used in the present invention is used. Manufactured.
The dimensions of the manhole made of the present polymer cement mortar obtained at this time are a side plate thickness of 110 mm, a top plate / bottom plate thickness of 130 mm, and a face plate thickness of 120 mm, and the product weight is 9700 kg.
In addition, specimens were prepared for testing and left indoors until the test material age (14 days).

Comparative Example 1
The production of ordinary concrete manhole members and ordinary concrete manholes will be described.
Materials used Cement: Ordinary Portland cement Coarse aggregate: Hard sandstone crushed stone from Iwase-cho, Ibaraki Prefecture 2005 (surface dry density 2.65 g / cm ³ )
Fine aggregate: Land sand from Hamaoka-cho, Ogasa-gun, Shizuoka (surface dry density 2.60 g / cm ³ , FM 2.75)
High performance water reducing agent: Naphthalene sulfonic acid formalin high condensate salt Water: Tap water Rebar: Steel bar

Formulation (kg / m ³ ) and manufacturing Amount of ordinary Portland cement 378 kg, coarse aggregate 989 kg, fine aggregate 826 kg, high-performance water reducing agent 1.5 kg, water 168 kg using a twin screw mixer with a capacity of 2 cubic meters The mixture was kneaded at 1 cubic meter, filled into a predetermined mold having reinforcing bars, and then molded by performing vibration compaction with a mold vibrator. Thereafter, steam curing was performed under the same conditions as in Example 1 to produce a normal concrete manhole member.
Next, an adhesion treatment was performed in the same manner as in Example 1 to produce an ordinary concrete manhole.
The dimensions of the normal concrete manhole obtained at this time are as follows: the side plate thickness is 180 mm, the top plate / bottom plate thickness is 200 mm, the end plate thickness is 140 mm, and the product weight is 14640 kg.
In addition, specimens were prepared for testing and left indoors until the test material age (14 days).

Bending strength test (JIS A 1171-2000), compressive strength test (JIS A 1108-1999), tensile strength test (JIS A 1113-1999), bending adhesion using each specimen manufactured in Example 1 and Comparative Example 1 A test was conducted.
In the bending adhesion test, a 4 × 4 × 16 cm specimen was cut at the center, the surfaces opposite to the cut surface were wiped with acetone, and then bonded with a putty-like two-component epoxy resin adhesive. The bending test was performed again at 4 × 4 × 16 cm. The thickness of the adhesive layer at this time is 1.5 mm.

  The various test results are shown in Table 1.

From the results described above, the polymer cement mortar manhole member of the present invention (Example 1) is superior in bending strength, compressive strength, tensile strength, and bending adhesive strength to the ordinary concrete manhole member (Comparative Example 1). I understand that
In particular, the fact that the bending adhesive strength is superior to that of an ordinary concrete manhole member (Comparative Example 1) indicates that the adhesiveness by the adhesive is also excellent.

Each member manufactured in Example 1 and Comparative Example 1 was bonded to manufacture a manhole.
Table 2 shows the thickness of each member and the product weight.

  From the results of this table, the polymer cement mortar manhole of the present invention (Example 1) is thinner than the ordinary concrete manhole (Comparative Example 1), and the product weight is 66% of the ordinary concrete manhole. is there. Further, as shown in Table 1 above, the strength of each manhole made of polymer cement mortar according to the present invention is superior.

A neutralization promotion test and a chloride ion penetration promotion test were performed using each specimen manufactured in Example 1 and Comparative Example 1.
The neutralization promotion test was conducted according to JISA 1171. In addition, the chloride ion penetration promotion test was performed for 4 cycles, with one cycle consisting of immersion in a 3% NaCl solution for 3 days and then leaving it to dry for 4 days. The results are shown in Table 3.

The neutralization depth and chloride ion depth of the polymer cement mortar manhole (Example 1) of the present invention were 0 mm, and resistance to penetration of the substance was observed. On the other hand, the normal concrete manhole (Comparative Example 1) has a neutralization depth of 5.3 mm and a chloride ion penetration depth of 12.5 mm, and the polymer cement mortar manhole of the present invention is resistant to these resistances. On the other hand, it can be seen that it has much better performance than ordinary concrete products.

Using each specimen (10 × 10 × 40 cm) manufactured in Example 1 and Comparative Example 1, a freeze-thaw test was performed up to 300 cycles.
The result is shown in FIG.

The air amount of the polymer cement mortar manhole of the present invention (Example 1) is 3.4%, but the relative dynamic elastic modulus is 95% or more in 300 cycles, no scaling is observed, and sufficient freezing and thawing resistance is obtained. Is recognized. This is considered to be because the polymer cement mortar manhole of the present invention has a low water cement ratio and the polymer filled the pores.
On the other hand, the normal concrete manhole (Comparative Example 1) had a relative dynamic elastic modulus of 60% or less up to 50 cycles.

As explained in detail above, the polymer cement mortar manhole of the present invention can be manufactured through steam curing, as is the case with most concrete products, when early-strength Portland cement is used as the hydraulic binder. It is.
In addition, when ordinary Portland cement and early strength Portland cement are used as the hydraulic binder, the polymer cement mortar manhole of the present invention can be manufactured by air curing.
Moreover, compared to conventional concrete products, the compressive strength is about twice, the bending strength is about three times, and the tensile strength and bending adhesive strength are about twice, so that it is possible to reduce the thickness and weight. Furthermore, as can be seen from the results of the neutralization promotion test, the chloride ion penetration promotion test, and the freeze-thaw test, it is much more durable than conventional concrete products.
Therefore, if the polymer cement mortar manhole of the present invention is used, a lightweight and durable polymer cement mortar manhole can be provided.

It is the freeze-thaw test result of the member for polymer cement mortar manholes of the present invention (Example 1) and the member for ordinary concrete manholes (Comparative Example 1).

Claims (5)

  A manhole made of polymer cement mortar, characterized by comprising Portland cement, aggregate consisting of fine aggregate, polymer emulsion, high-performance water reducing agent, and antifoaming agent. 2. The polymer cement mortar manhole according to claim 1, wherein the water cement ratio is 25% or less. 3. The polymer cement mortar manhole according to claim 1, wherein at least one powder selected from blast furnace slag powder, fly ash, silica fume, limestone powder, and silica stone powder is added.   4. The polymer cement mortar manhole according to claim 1, wherein the polymer emulsion is a poly (meth) acrylic acid ester-based water-soluble polymer. The manhole made of polymer cement mortar according to claim 1, wherein the Portland cement is an early-strength Portland cement.

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