JP6405066B1 - Metal fiber and concrete structure using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal fiber capable of preventing exfoliation and collapse even when a crack or the like occurs in a concrete material without performing a special coating treatment on the surface, and a concrete structure using the metal fiber. The present invention is a metal fiber made of high weathering steel and mixed as a reinforcing material inside a concrete material, and a concrete structure to which the metal fiber is applied. In the present invention, the high weathering steel constituting the metal fiber is a fibrous steel material containing at least C at 0.18% or less and Si at 1.00% or less by mass%. [Selection] Figure 1

Description

  The present invention relates to a concrete structure reinforced with metal fibers, which is applied to buildings such as buildings and bridges, and in particular, a metal that is excellent in salt damage resistance and corrosion resistance and can prevent peeling and collapse of a concrete material. The present invention relates to a fiber and a concrete structure to which the fiber is applied.

  Concrete structures applied to buildings, etc. are constructed as those with reinforcing bars inside the concrete material, but such concrete structures have significant strength when the contained reinforcing bars deteriorate. descend. In particular, when it is applied to structures constructed near the coastline, seawater and incoming salt from the sea penetrate into the concrete material to generate chloride ions, which chloride ions are generated on the surface of the reinforcing bar. The oxide film is destroyed and corrosion (so-called “rust”) proceeds.

  When such corrosion of the reinforcing bar surface occurs, the volume of the reinforcing bar expands, cracks occur in the concrete material around the reinforcing bar, and eventually the concrete material breaks, causing peeling or collapse. At this time, in the concrete structure reinforced with reinforcing bars, the portion of the concrete material other than the reinforcing bars is separated as a large lump by cracking, so there is a problem that the damage when such a large lump of concrete material falls is great .

  As a technique for solving such a problem, for example, Patent Document 1 discloses a technique of dispersing and mixing a metal fiber having a rust preventive film coated with a coating made of an alkyd resin on the surface as a reinforcing material. It is disclosed. According to such a technique, even if cracks are generated in the concrete material, it is said that a large number of metal fibers can be prevented from peeling and collapsing, and the surface rust preventive film can suppress the occurrence of rust on the metal fibers. .

JP 2001-146442 A

  In the manufacturing process of the metal fiber described in Patent Document 1, it is necessary to provide a step of applying a resin coating, and the weight increases by the amount of the resin of the coating compared to a metal fiber having the same diameter. . In addition, when a large number of metal fibers come into contact with each other when embedding in a concrete material, the coating tends to rub and crack, and the minute cracks generated by these rubs and cracks develop over time and damage the coating. For this reason, it is necessary to pay close attention not to damage the coating surface not only during mixing but also during transportation and construction, and handling becomes complicated. Further, since the resin coating has low bonding property with the concrete material, there is a problem that when the metal fiber is simply linear, the concrete lump separated by cracks or the like is removed from these metal fibers.

  Therefore, an object of the present invention is to provide a metal fiber capable of preventing peeling and collapsing even if a crack or the like occurs in a concrete material without performing a special coating treatment on the surface, and a concrete structure to which the metal fiber is applied. is there.

  In order to solve the above-mentioned problem, the metal fiber mixed as a reinforcing material in the concrete material according to the present invention is a fiber containing, by mass%, at least C of 0.18% or less and Si of 1.00% or less. It is characterized by comprising a highly weather-resistant steel that is a steel sheet.

  Further, the concrete structure in which the above-mentioned metal fibers are mixed as a reinforcing material in the concrete material according to the present invention is one kind selected from Portland cement, blast furnace cement, fly ash cement, and silica cement. It is configured.

  According to this invention, even if cracking or the like occurs in the concrete material without performing special coating treatment on the surface by using high weathering steel having high corrosion resistance as the metal material constituting the metal fiber. Separation and collapse can be prevented.

  In the above-described invention, the high weather resistance steel is in mass%, at least C is 0.08% or less, Si is 1.00% or less, Ni is 7.00 to 10.50%, Cr is 18.00 to It is a SUS high weathering steel contained at 20.00%. At this time, the SUS high weathering steel is preferably non-magnetic.

  In the invention described above, the high weather resistance steel is in mass%, at least C is 0.18% or less, Si is 0.15 to 0.65%, Mn is 1.25% or less, and Ni is 0. Ni-based high weathering steel contained in 70 to 3.50%. At this time, the Ni-based high weather resistance steel preferably contains Ni in a range of 0.70 to 1.70% or in a range of 2.50 to 3.50%. And the maximum diameter of the said highly weather-resistant steel is 0.5 thru | or 0.8 mm as the example.

  Furthermore, in the above-described invention, at least a part of the high weathering steel is bent or refracted. Moreover, the bending area | region which makes an acute angle may be formed in the both ends of the said highly weather-resistant steel.

  Furthermore, in the above-described invention, the high weather resistance steel is formed in an annular shape including an overlapping region having a predetermined width. At this time, the high weather resistance steel is formed in an annular shape or a polygonal annular shape.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the outline of the metal fiber by Example 1 of this invention, and the concrete structure to which this is applied, Comprising: Fig.1 (a) is a side fragmentary sectional view of a concrete structure, FIG.1 (b) It is the side view which expanded one of the metal fibers shown to Fig.1 (a), FIG.1 (c) is the fragmentary sectional view to which the vicinity of the concrete material containing the metal fiber shown in FIG.1 (b) was expanded. is there. It is a component table | surface which shows the specific example of the metal fiber by Example 1 of this invention. It is a side view which shows the outline | summary of the metal fiber by Example 2 of this invention. It is a side view which shows the outline | summary of the metal fiber by Example 3 of this invention. It is a side view which shows the outline | summary of the metal fiber by Example 4 of this invention.

  Hereinafter, the concrete structure of the metal structure by this invention and the concrete structure to which this is applied is demonstrated using drawing.

<Example 1>
FIG. 1 is a diagram showing an outline of a metal fiber according to Example 1 of the present invention and a concrete structure to which the metal fiber is applied, and FIG. 1 (a) is a side partial sectional view of the concrete structure. (B) is the side view which expanded one of the metal fibers shown to Fig.1 (a), FIG.1 (c) expanded the vicinity of the concrete material containing the metal fiber shown to FIG.1 (b). It is a fragmentary sectional view. Moreover, FIG. 2 is a component table | surface which shows the specific example of the metal fiber by Example 1 of this invention. As shown in FIG. 1A, in the concrete structure according to the first embodiment of the present invention, a large number of metal fibers 100 are dispersed and mixed in the concrete material 20.

  For example, the concrete material 20 is a material containing cement made of one kind selected from Portland cement, blast furnace cement, fly ash cement, and silica cement. For example, the cement material 20 is made of bone, such as sand or gravel. It is formed by mixing and solidifying a material or an admixture such as blast furnace slag fine powder, fly ash or silica fume, a chemical admixture and water. In addition, as concrete material 110 in a typical example of this invention, if the above-mentioned cement is included, high strength concrete can be selected by selecting various kinds of aggregates or amounts of admixtures. And various types of concrete such as lightweight concrete or watertight concrete.

  As shown in FIG. 1B, the metal fiber 100 according to the first embodiment of the present invention includes, as an example, both end regions 102a and 102b of the fiber, and a bent region 104 connecting these regions. And as shown in FIG.1 (c), the metal fiber 100 is used in the aspect embedded in the concrete material 20. FIG.

  In the concrete structure 10 according to Example 1 of the present invention, as shown in FIG. 1C, for example, when the concrete material 20 has a crack C such as a crack, and the concrete material 20 is divided into two, An external force F acts in the direction that separates the crack C. At this time, since the metal fiber 100 includes the bent region 104, the both end regions 102a and 102b are arranged obliquely with respect to the direction of the external force F, so that the concrete material 20 is less likely to come off from the metal fiber 100, and separated concrete. The peeling and collapse of the material 20 are suppressed.

  The metal fiber 100 is made of high weathering steel, which is a fibrous steel material containing at least C at 0.18% or less and Si at 1.00% or less by mass%. As an example, the metal fiber 100 is configured as a high weather resistance steel containing component elements as shown in FIG. At this time, as the metal fiber 100, for example, a cross section having a diameter of 0.5 mm to 0.8 mm having an arbitrary cross section such as a rectangle, a hexagon, an octagon, a circle, or a semicircle can be adopted.

  The high weather resistance steels constituting the metal fiber 100 according to Example 1 of the present invention are all mass%, C is 0.18% or less, Si is 0.55% or less, Mn is 1.25% or less, P 0.035% or less, S is 0.035% or less, Cu is 0.20% to 0.35%, Cr is 0.30 to 0.55%, and the balance is Fe and inevitable impurities. Stainless steel can be exemplified. And as the typical example, steel A shown, for example in FIG. 2 is applied.

  Further, the high weather resistance steel constituting the metal fiber 100 according to Example 1 of the present invention is, as a modification thereof, all in mass%, C is 0.18% or less, and Si is 0.15 to 0.65%. , Mn is 1.25% or less, P is 0.035% or less, S is 0.035% or less, Cu is 0.30% to 1.00%, Cr is 0.08% or less, and Ni is 0.70. An example is Ni-based high weathering steel having 3.5 to 30% and the balance being Fe and inevitable impurities. At this time, the Ni-based high weathering steel preferably contains Ni in the range of 0.70 to 1.70% or in the range of 2.50 to 3.50%. And as the typical example, the steel B and the steel C which are shown, for example in FIG. 2 are applied.

  Furthermore, the high weather resistance steel which comprises the metal fiber 100 by Example 1 of this invention, as a modification, all are the mass%, C is 0.08% or less, Si is 1.00% or less, Mn is 2.50% or less, P is 0.045% or less, S is 0.030% or less, Ni is 7.00 to 10.50%, Cr is 18.00 to 20.00%, and N is 0.10 to An example is SUS high weathering steel having 0.25%, the balance being Fe and inevitable impurities. And as a typical example, steel D shown, for example in Drawing 2 is applied.

  At this time, the SUS high weathering steel is preferably non-magnetic. Thereby, for example, even when the concrete structure 10 in which the metal fiber 100 made of SUS high weather resistance steel is mixed in the concrete material 20 is applied to a structure that generates a magnetic field such as a linear motor car. The concrete structure 10 is not affected by the magnetic field.

  With such a configuration, the metal fiber and the concrete structure according to the present invention can be formed from, for example, Portland cement, blast furnace cement, fly ash cement, and silica cement by configuring metal fibers with high weather resistance steel including a predetermined component range. Even if the reinforcing bars are embedded in a general concrete material containing one selected type of cement, sufficient corrosion resistance against the environment containing salt and the neutralization of the concrete material itself can be obtained. And by utilizing the characteristic that it is a metal fiber, even if a crack etc. arise in concrete material, without performing a special coating process on the surface, peeling and collapse can be prevented.

<Example 2>
FIG. 3 is a side view showing an outline of a metal fiber according to Example 2 of the present invention. As shown in FIG. 3, the metal fiber 200 according to the second embodiment of the present invention includes refractive regions 202a and 202b located at both ends of the fiber, and a connection region 204 that connects these regions. In the second embodiment, the metal material constituting the metal fiber 200 is the same as that in the first embodiment as shown in FIG.

  In the metal fiber 200 according to the second embodiment of the present invention, the refracting regions 202a and 202b are formed as bent regions whose ends form an acute angle. Thereby, since many metal fibers 200 mixed in the concrete material 20 can be connected in a manner in which the adjacent metal fibers 200 are caught by these refractive regions 202a and 202b, the tensile strength of the concrete structure 10 can be increased. Strength is improved.

  With such a configuration, the metal fiber according to Example 2 of the present invention and the concrete structure to which the metal fiber is applied include a refractive region at both ends, so that the metal fibers are connected to each other in addition to the effects obtained in Example 1. It is possible to improve the tensile strength of the concrete structure.

<Example 3>
FIG. 4 is a side view showing an outline of a metal fiber according to Example 3 of the present invention. As shown in FIG. 4, the metal fiber 300 according to the third embodiment of the present invention is an annular member including an overlapping region 302 where both ends of the fiber overlap with a predetermined width, and a connection region 304 other than the overlapping region 302. Is formed. In Example 3, the metal material constituting the metal fiber 300 is the same as that in Example 1 as shown in FIG.

  Here, for example, when a general metal fiber as shown in Patent Document 1 is mixed in a concrete material, the metal fibers are intertwined during kneading, and a fiber lump called “steel ball” is generated. was there. On the other hand, in the metal fiber 300 according to the third embodiment of the present invention, since both ends 302a and 302b of the fiber overlap in the overlap region 302, the closed space S is formed, so that the metal fibers 300 are entangled during kneading. And the occurrence of so-called steel balls is suppressed.

  With such a configuration, the metal fiber according to Example 3 of the present invention and the concrete structure to which the metal fiber is applied have the effect obtained in Example 1 because the metal fiber is configured to form an annular closed space. In addition, it is possible to suppress the occurrence of so-called “steel balls” in which the metal fibers are intertwined to form a lump.

<Example 4>
FIG. 5 is a side view showing an outline of a metal fiber according to Example 4 of the present invention. As shown in FIG. 5, the metal fiber 400 according to the fourth embodiment of the present invention has a triangular annular shape including an overlapping region 402 where both ends of the fiber overlap with a predetermined width at the corners, and a connection region 404 other than the overlapping region 402. It is formed as a member. In Example 4, the metal material constituting the metal fiber 400 is the same as that in Example 1 as shown in FIG.

  In the metal fiber 400 according to the fourth embodiment of the present invention, both ends 402a and 402b of the fiber are each formed as a bent region, and they are overlapped to form one corner of a triangle. Thereby, the metal fiber 400 forms the closed space S by overlapping in the overlapping region 402, and the rigidity of the overlapping region 402 including the bent region is enhanced. In the specific example shown in FIG. 5, the case where the metal fiber 400 has a triangular ring shape is illustrated, but a polygonal shape of a quadrangle or more may be employed.

  With such a configuration, the metal fiber according to Example 4 of the present invention and the concrete structure to which the metal fiber is applied are formed in a polygonal annular shape in which overlapping regions of the end portions are arranged at the corners. In addition to the obtained effects, the rigidity of the metal fiber itself can be improved. As a result, it becomes possible to function as a resistance to an external force from the concrete material loaded in the normal direction of the annularly formed metal fiber.

  As mentioned above, although the Example by this invention and the modification based on this were demonstrated, this invention is not necessarily limited to these examples. In addition, those skilled in the art will be able to find various alternative embodiments and modifications without departing from the spirit of the present invention or the scope of the appended claims.

DESCRIPTION OF SYMBOLS 10 Concrete structure 20 Concrete material 100, 200, 300, 400 Metal fiber 102a, 102b Both ends area 104 Bending area 202a, 202b Refraction area 204 Connection area 302 Overlapping area 302a, 302b (Fiber) both end 304 Connection area 402 Overlapping area 402a 402b (fiber) both ends 404 connection area

Claims (11)

It is formed from a fibrous high weather resistant steel which is formed into an annular shape including an overlapping region of a predetermined width by bending or refracting at least a part thereof, and bent regions forming acute angles at both ends thereof. It is a metal fiber mixed as a reinforcing material inside the concrete material,
The high weather-resistant steel is in mass%, at least C is 0.18% or less, Si is 0.15 to 0.65%, Mn is 1.25% or less, Cu is 0.30 to 1.00%, A metal fiber characterized by being a Ni-based high weathering steel containing Cr at 0.08% or less and Ni at 0.70 to 3.50% . The metal fiber according to claim 1 , wherein the Ni-based high weathering steel contains Ni in a range of 0.70 to 1.70% . The metal fiber according to claim 1 , wherein the Ni-based high weathering steel contains Ni in a range of 2.50 to 3.50% . The metal fiber according to any one of claims 1 to 3 , wherein a maximum diameter of the high weather resistant steel is 0.5 to 0.8 mm . The metal fiber according to any one of claims 1 to 4, wherein the high weather resistance steel is formed in an annular shape . The metal fiber according to any one of claims 1 to 4, wherein the high weather resistance steel is formed in a polygonal annular shape . It is formed from a fibrous high weather resistant steel which is formed into an annular shape including an overlapping region of a predetermined width by bending or refracting at least a part thereof, and bent regions forming acute angles at both ends thereof. It is a metal fiber mixed as a reinforcing material inside the concrete material,
The high weather resistance steel is in mass%, at least C is 0.08% or less, Si is 1.00% or less, Ni is 7.00 to 10.50%, Cr is 18.00 to 20.00%. Ri Oh in the SUS-based high weathering steel containing,
A metal fiber which is non-magnetic when mixed into the concrete material . The metal fiber according to claim 7 , wherein the maximum weather resistant steel has a maximum diameter of 0.5 to 0.8 mm . The metal fiber according to claim 7 or 8 , wherein the high weather resistance steel is formed in an annular shape . The metal fiber according to claim 7 or 8 , wherein the high weather resistance steel is formed in a polygonal annular shape . A concrete structure in which the metal fiber according to any one of claims 1 to 10 is mixed as a reinforcing material in a concrete material,
The concrete material is composed of one kind selected from Portland cement, blast furnace cement, fly ash cement, and silica cement.

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