JP2001207442A - Sheet pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet pile, capable of reducing the thickness of a section, having a longer size with a wide width and having excellent durability by using an extra-high strength concrete hardening body having high strength property, high toughness, impact resistance and high durability. SOLUTION: The sheet pile is constituted of the hardening body of a compound, containing at least cement, pozzolan fine powder, aggregate particle with particle size 2 mm or less, water and a water reducing agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet pile using an ultra-high-strength concrete hardened body.

[0002]

2. Description of the Related Art Conventionally, concrete sheet piles or steel sheet piles have been used for earth retaining walls such as rivers, drainage channels, retaining walls, seawalls and waterproof walls. Concrete sheet piles, compared to steel sheet piles,
While excellent in durability, maintenance and repair costs for rust prevention, aesthetics, and the like, ordinary concrete has a drawback that the weight of the structure increases due to its material properties. That is, when a sheet pile is hit, not only compressive stress but also tensile stress is generated, and bending stress is applied due to eccentricity and the like, which may lead to breakage of the sheet pile. Further, if the impact is performed while loosening the ground in order to reduce the impact force, the horizontal resistance decreases, the horizontal displacement of the sheet pile and the bending moment act, and the safety of the structure decreases. For this reason, it is necessary to increase the cross section of the concrete sheet pile and increase the strength, but it has a disadvantage that the weight is increased and a large mechanical force must be used for transportation and the like.

On the other hand, the use of a pressed concrete sheet pile or a prestressed concrete sheet pile makes it possible to provide a predetermined strength to a certain small cross section.
~ 80MPa, bending strength is about 6 ~ 10MPa,
In order to further reduce the cross section and make the sheet pile wide and long, there is a limit to the dimensions of the members. Further, although concrete has excellent durability, there remains a problem in long-term use such as erosion by seawater and peeling due to freezing and thawing.

[0004]

Therefore, the present invention provides an ultra-high-strength concrete having excellent high-strength characteristics, high toughness, impact resistance and high durability while maintaining the excellent characteristics of the concrete. By using a system-based hardened body, the cross-section thickness can be reduced, wide and long dimensions can be made, and a safer structure can be constructed without the need to loosen the ground during construction. The purpose is to provide.

[0005]

In order to achieve the above object, according to the sheet pile of the present invention, at least cement, pozzolanic fine powder, aggregate particles having a particle diameter of 2 mm or less,
It is composed of a cured product of a composition containing water and a water reducing agent (Claim 1). The composition contains metal fibers and / or organic fibers (Claim 2). 1.
0 mm, a steel fiber having a length of 2 to 30 mm (claim 3), wherein the organic fiber is a vinylon fiber having a diameter of 0.005 to 1.0 mm and a length of 2 to 30 mm, a polypropylene fiber, a polyethylene fiber, an aramid fiber; It is one or more fibers selected from acrylic fiber and carbon fiber (Claim 4), the composition contains an inorganic powder having an average particle size of 3 to 20 μm (Claim 5), and the composition has an average particle size of 1 mm It contains the following fibrous particles or flaky particles (claim 6). Hereinafter, the present invention will be described in detail.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION As a cement used for a hardened material constituting a sheet pile of the present invention, various cements such as Portland cement, mixed cement, and quick-setting cement can be used. Portland cement is usually, fast,
Various Portland cements such as ultra-high strength, medium heat, sulfate resistant, low heat, white color etc. can be used, but each of the medium heat, sulfate resistant, low heat Portland cement contains aluminate mineral (C ₃ A) It is preferable because the amount is small and the fluidity is good. Mixed cements such as fly ash cement, blast furnace cement, silica cement and the like are preferred from the viewpoint of increasing fluidity because Portland cement content in the composition is relatively smaller than other cements. In order to improve the early strength of the cured product, it is preferable to use early-strength Portland cement, and quick-setting cement hardens in a short period of time, so fluidity is quickly lost. It is effective when it is done.

[0007] The amount of cement used is determined in conjunction with the amount of pozzolanic fine powder to be described later. The unit cement amount in the composition is 500 to 1000 kg / m ³ , preferably 700 to 850 kg / m ³ . By setting the range, the compressive strength is 150 MPa in combination with the action with various compounds.
As described above, particularly, a cured product for ultra-high strength of 200 MPa or more can be obtained. When the unit cement amount is less than 500 kg / m ³ , it is difficult to obtain the intended super-strength hardened body, and when the cement amount exceeds 1000 kg / m ³ , together with the use of pozzolanic fine powder, Mixing of the compound becomes difficult, which is not preferable.

Next, the pozzolanic fine powder is a fine powder involved in the pozzolanic reaction with cement, and includes silica fume, silica dust, fly ash, slag, volcanic ash, and the like.
Those having an average particle size of less than 1.5 μm, such as silica sol and precipitated silica, are used. Among them, silica fume has an average particle size of 1.0 μm or less, does not require pulverization, and is suitable for the pozzolanic reaction. With the pozzolanic fine powder, concrete is densified by its microfiller effect and cement dispersing effect, and the compressive strength is improved. On the other hand, if the amount of the fine powder increases, the unit water amount increases. Therefore, the amount of the pozzolanic fine powder is preferably 5 to 50 parts by weight based on 100 parts by weight of the cement.

In the present invention, the aggregate is sand used in ordinary concrete, such as river sand, land sand, sea sand, and the like.
Crushed sand, silica sand and a mixture thereof can be used, and the particle diameter is 2 mm or more when passing through a sieve of 85% by weight, preferably 1.5 mm or more when passing through a 85% by weight, more preferably 1.2 mm or more through a sieve. The amount used is 85% by weight or more. By using such aggregate particles, the separation resistance of the composition can be increased, and the filling degree and strength of the cured product can be increased. By setting the amount of the above-mentioned aggregate to be in the range of 50 to 250 parts by weight, preferably 80 to 180 parts by weight with respect to 100 parts by weight of cement, the workability and the separation resistance of the concrete are excellent, and after hardening. While maintaining the strength and resistance to cracks, an economically cured product can be obtained.

In the present invention, in addition to the above-mentioned aggregate, the average particle size is 3.0 to 20 μm, preferably 4 to 10 μm.
The filling density of the cured product can be further increased by blending an inorganic powder of μm. Examples of the inorganic powder include quartz powder, for example, quartz or amorphous quartz, opal or cristobalite silica-containing powder, or rock powder, limestone powder, blast furnace slag, volcanic ash, classified fly ash, or Al ₂ O ₃ Oxide powder, such as SiC ₂ , and carbide powder, such as SiC ₂ , and nitride powder, such as SiN, among which quartz powder is preferred in terms of cost and quality stability of the cured product. When the inorganic powder is contained in the range of 50 parts by weight or less, preferably in the range of 20 to 35 parts by weight with respect to 100 parts by weight of cement, dense filling with good fluidity and excellent strength of the cured product is achieved. The structure can be easily formed.

Next, the present invention uses a water reducing agent in combination. As the water reducing agent, a lignin-based, naphthalene sulfonic acid-based, melamine-based, polycarboxylic acid-based water reducing agent, an AE water reducing agent, a high performance water reducing agent, or a high performance AE water reducing agent can be used. Among them, it is preferable to use a high performance water reducing agent or a high performance AE water reducing agent. In the present invention, one of the features is that the volume of the fine powder occupied in the cured body is larger than that of the conventional concrete, but also in this case, by appropriately adjusting the amount of the water reducing agent, Concrete can be given a predetermined fluidity. The amount of the water reducing agent added (outside the cement) is 0.1 to 10 in terms of solid content with respect to the cement, based on the fluidity and separation resistance of the concrete, the strength after hardening, and the cost. weight%,
Preferably, it is 0.5 to 4.0% by weight. The amount added is 0.
If the content is less than 1% by weight, there is substantially no water reducing effect.
Even if it is added in excess of 0% by weight, the effects of improving water reduction and fluidity level off.

In the present invention, the water / cement ratio is preferably from 10 to 30% by weight, more preferably from 15 to 25% by weight, from the viewpoint of the fluidity and separation resistance of the concrete, the strength and the durability of the cured product.

In the present invention, from the viewpoint of increasing the bending strength of the cured product, it is preferable that the compound contains metal fibers and / or organic fibers. Examples of the metal fiber include a steel fiber and an amorphous fiber. Among them, the steel fiber is excellent in strength, and is preferable from the viewpoint of cost and availability. Metal fibers have a diameter of 0.01 to
Those having a length of 1.0 mm and a length of 2 to 30 mm are preferred. If the diameter is less than 0.01 mm, the strength of the fiber itself is insufficient, and the fiber tends to be cut when subjected to tension. If the diameter exceeds 1.0 mm, the number of pieces with the same blending amount decreases, and the flexural strength of concrete decreases. If the length exceeds 30 mm, fiber balls tend to be formed during kneading. Length 2mm
If less than this, the adhesion to the matrix decreases and the bending strength decreases.

The amount of the metal fiber is preferably less than 4%, more preferably less than 3.5% of the volume of the cured product after setting. The content of the metal fiber is determined from the viewpoint of fluidity and bending strength of the cured product. In general, as the content of the metal fiber increases, the bending strength improves, but on the other hand, the unit water amount also increases in order to secure fluidity. Therefore, the content of the metal fiber is preferably the above-mentioned amount.

Examples of the organic fiber include vinylon fiber, polypropylene fiber, polyethylene fiber, aramid fiber, acrylic fiber, carbon fiber and the like. Organic fiber is
Those having a diameter of 0.005 to 1.0 mm and a length of 2 to 30 mm are preferred. The content of the organic fibers is preferably less than 10%, more preferably less than 7% of the volume of the cured product after coagulation. In the present invention, metal fibers and organic fibers may be used in combination.

In the present invention, from the viewpoint of increasing the toughness of the cured product, it is preferable to include fibrous particles or flaky particles having an average particle size of 1 mm or less. Here, the particle size of a particle is the size of its maximum dimension (in particular, its length in the case of fibrous particles). Examples of the fibrous particles include wollastonite, bauxite, and mullite, and examples of the flaky particles include mica flake, talc flake, vermiculite flake, and alumina flake. The blending amount of the fibrous particles or flaky particles is preferably 35 parts by weight or less, more preferably 10 to 25 parts by weight, based on 100 parts by weight of cement, from the viewpoint of the fluidity of the concrete, the strength and the toughness of the cured product. From the viewpoint of enhancing the toughness of the cured product, it is preferable to use fibrous particles having a needleiness expressed by a length / diameter ratio of 3 or more.

[0017] In addition to the above-described components, the present invention is generally used for hardening hardened concrete used in concrete.
Various concrete admixtures such as quick-setting materials, high-strength admixtures, hydration accelerators, setting modifiers and the like can also be used.

The method of mixing and kneading the above components is not limited, and it is sufficient that the components can be uniformly mixed and kneaded, and various mixers such as an omni mixer, a pan-type mixer, a biaxial kneading mixer, and a tilting mixer can be used. . Further, the order of adding the components is not particularly limited. Various molding methods and curing methods for ordinary concrete can be applied to the molding and curing of the mixture. In addition to cast molding, centrifugal molding and the like can be applied to tubular bodies. Any of the methods of normal pressure steam curing and high temperature and high pressure curing can be employed, and if necessary, these can be combined to obtain an ultra-high strength cured product. Also,
It is also possible to arrange reinforcing bars in the same manner as in the case of conventional concrete, and additionally, to provide a prestressed product.

The hardened body containing the above-mentioned compound is prepared as a precast product having various cross-sectional shapes such as a flat type, a groove type, and a corrugated type, like the conventional reinforced concrete sheet pile, prestressed sheet pile, and pressurized concrete sheet pile. It is possible to obtain a sheet pile having a reduced cross-sectional thickness, a wide width and a long dimension, high strength characteristics, high toughness, impact resistance and high durability.

[0020]

The present invention will be described below with reference to examples. (Materials used) Cement: Low heat Portland cement (manufactured by Taiheiyo Cement Co., Ltd.) Pozzolanic fine powder: silica fume (average particle size 0.7 μm)
m) Aggregate: 2: 1 (weight ratio) mixture of silica sand No. 4 and silica sand No. 5 (100% by weight of 2 mm sieve passing amount) Metal fiber: steel fiber (diameter: 0.2 mm, length: 15 m)
m) High-performance AE water reducing agent: Polycarboxylic acid-based high-performance AE water reducing agent Water: tap water Quartz powder (average particle diameter 7 μm) Fibrous particles: wollastonite (average length 0.3 mm,
Length / diameter ratio 4)

Example 1 100 parts by weight of low heat Portland cement, 32.5 parts by weight of silica fume, 120 parts by weight of aggregate, 1.0% by weight (solid content) of high performance AE water reducing agent based on cement, water / cement ratio Under the condition of 22% by weight, each material was put into a biaxial kneading mixer at a time and kneaded. Next, before (20 ° C)
After 48 hours, steam cure at 90 ° C for 48 hours,
mm, 100 mm long cylinder (for compression test), and width 4
A rod-shaped (for bending test) molded article having a thickness of 0 mm, a length of 160 mm, and a thickness of 40 mm was obtained. The compression strength of the obtained molded product is 2
The bending strength was 10 MPa and the bending strength was 25 MPa. In addition, the flow value of the kneaded material was 270 mm.

Example 2 Example 1 except that steel fibers were added at 2% of the volume in the formulation.
A molded product was obtained in the same manner as described above. The compression strength of the obtained molded product was 210 MPa, the bending strength was 47 MPa, and the flow value of the kneaded product was 250 mm.

Example 3 A molded product was obtained in the same manner as in Example 1 except that 30 parts by weight of quartz powder and 24 parts by weight of wollastonite were added to the compound of Example 2. The compression strength of the obtained molded product was 23
The bending strength was 0 MPa, the bending strength was 47 MPa, and the flow value of the kneaded material was 250 mm.

COMPARATIVE EXAMPLE 100 parts by weight of ordinary Portland cement as cement, 160 parts by weight of fine aggregate (crushed sand from Yamagata), and 300 parts by weight of coarse aggregate (crushed stone from Chichibu) as an aggregate, water / cement ratio of 40% by weight A molded article was obtained in the same manner as in Example 1 except that The compression strength of the obtained molded product was 60 MPa, the bending strength was 7 MPa, and the slump flow value of the kneaded product was 550 mm.

Example 4 The molded articles obtained in Examples 1 to 3 and Comparative Example were subjected to an abrasion resistance and impact resistance test. The wear resistance was measured by a pin-on-disk method, and the impact test was performed by the Charpy method. As a result of the measurement, assuming that the molded article wear amount of Example 1 is 100, that of Examples 2 and 3 is 110,
It was 110 and 60 in the comparative example. Further, assuming that the energy absorption rate in Example 1 is 1, Example 2,
3 was 80 and 100, respectively, and was 1/5 in the comparative example.

Example 5 A freeze-thaw test was performed using the molded products obtained in Examples 1 to 3 and Comparative Example, and the degree of deterioration of the molded product was determined by the relative dynamic elastic modulus ratio based on the number of freeze-thaw cycles and the dynamic elastic modulus. Was determined by measuring. The measurement result was 1000 freeze-thaw cycles.
Assuming that the kinetic elastic coefficients of Examples 1 to 3 at 100 times are 100, it was 70 in the comparative example.

[0027]

According to the present invention, the compressive strength is increased to 200MP.
a or more, bending strength is 20MPa or more, furthermore 40MPa
It is possible to obtain an ultra-dense cured body with a or more,
It is extremely excellent in abrasion resistance and surface erosion resistance, and can be used as a sheet pile having extremely high durability. Further, according to the present invention, due to its ultra-high strength properties and impact resistance properties, the dimensions of the members can be reduced, the weight can be reduced and the width can be increased, and the drying shrinkage is small, the dimensional accuracy is excellent, and sheet piles are used. When constructing structures, it is safer without having to loosen the ground during construction,
The workability is extremely excellent. Further, it is possible to cope with a change in the ground when the sheet pile is constructed over a long section without changing the construction method.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C04B 20:00 C04B 20:00 B 14:48) 14:48) D 103: 32 103: 32

Claims (6)

[Claims] 1. A sheet pile comprising at least a cured product of a compound containing cement, pozzolanic fine powder, aggregate particles having a particle size of 2 mm or less, water and a water reducing agent. 2. The sheet pile according to claim 1, wherein the composition comprises metal fibers and / or organic fibers. 3. The metal fiber has a diameter of 0.01 to 1.0 mm,
The sheet pile according to claim 2, which is a steel fiber having a length of 2 to 30 mm. 4. The organic fiber has a diameter of 0.005 to 1.0 m.
3. The sheet pile according to claim 2, wherein the sheet pile is at least one fiber selected from vinylon fibers, polypropylene fibers, polyethylene fibers, aramid fibers, acrylic fibers, and carbon fibers having a length of 2 to 30 mm. 5. The sheet pile according to claim 1, wherein the composition contains an inorganic powder having an average particle size of 3 to 20 μm. 6. The sheet pile according to claim 1, wherein the composition contains fibrous particles or flaky particles having an average particle size of 1 mm or less.