CN1699707A - concrete lining blocks - Google Patents

Abstract

To provide a concrete segment which not only exhibits sufficient increase in strength, but also allows smooth filling of concrete thereto and contributes to suppression of cost increase. The concrete segment has a reinforcing sheet or a reinforcing mesh embedded in a front surface or a corner portion thereof.

Description

concrete lining blocks

technical field

The invention relates to a concrete lining block for tunnel lining.

This application claims priority on the basis of Japanese Patent Application No. 2004-91568 filed on March 26, 2004, the contents of which are incorporated herein by reference.

Background technique

At present, for example, a cylindrical underground structure such as a shield tunnel is formed by a construction method in which a lining block having a cylindrical surface shape formed by dividing a cylindrical lining body in the axial direction and the circumferential direction is arranged on the excavation surface, Joining is performed in the extending direction and the circumferential direction of the lining body, thereby forming a cylindrical lining body.

As the above-mentioned lining block, a concrete lining block having a reinforced concrete structure, a synthetic lining block obtained by pouring concrete into a steel frame, and the like are known.

As a reinforcement method for concrete lining blocks, there are methods of increasing the density of steel bars, using steel bars with larger diameters, and forming SRC structures (steel-encased reinforced concrete) using reinforcing steel skeletons as described in JP-A-2001-27099.

However, the above conventional reinforcement method for concrete lining blocks has the following problems.

That is, the reinforcement method of increasing the density of steel bars or using steel bars with larger diameters will affect the fluidity of the concrete poured later, making the filling efficiency worse, and the processing of the steel bars is time-consuming and laborious, resulting in problems such as increased costs.

In addition, in the reinforcement method of forming the SRC structure using a steel frame for reinforcement, there is a problem of an increase in cost because the steel frame itself is expensive.

Contents of the invention

The present invention was made in view of the above problems, and an object of the present invention is to provide a concrete lining block which can increase its own strength without increasing the cost and which can be filled with concrete smoothly during manufacture.

Another object of the present invention is to provide a concrete lining block which is less prone to surface cracks and corner defects.

The concrete lining block of the present invention is characterized by mixing reinforcing fibers.

In this concrete lining block, it is preferable to form the above-mentioned reinforcing fibers into a network-like fiber structure.

In this concrete lining block, a reinforcing sheet made of the reinforcing fiber may be embedded in the surface portion of the concrete lining block.

Alternatively, in this concrete lining block, a reinforcing sheet made of the above-mentioned reinforcing fiber may be embedded in the corner portion of the above-mentioned concrete lining block.

In addition, in this concrete lining block, the above-mentioned reinforcing fibers are preferably basalt fibers.

Because the present invention mixes reinforcing fibers in the concrete lining blocks, the strength of the concrete itself can be improved, thereby increasing the strength of the concrete lining blocks without increasing the density of steel bars disposed inside or using larger diameter steel bars.

According to the present invention, the reinforcing fibers can be formed into a network-like fiber structure, and by arranging the fiber structure at a specific position in the concrete lining block, this part can be reinforced emphatically and effective reinforcement treatment can be performed.

According to the present invention, since the reinforcing sheet is embedded in the surface portion of the concrete lining block, it is possible to prevent cracks in the surface portion of the concrete lining block that tend to occur during or after construction. In addition, even if cracks occur, cracks can be effectively dispersed to suppress an increase in crack width. In addition, in the case of tunnel construction, it is possible to prevent peeling of the surface of the concrete lining block due to deterioration of concrete due to aging or the like after construction.

According to the present invention, since the reinforcing sheets are embedded in the corners, the corners of the concrete lining block where the load is most likely to be concentrated during or after construction can be reinforced emphatically, and defects in the corners can be avoided.

Since basalt fibers have higher strength even compared with, for example, glass fibers with excellent strength, and are excellent in acid resistance and alkali resistance, when basalt fibers are used as reinforcing fibers of concrete lining blocks in the present invention, it is possible to obtain Long-term stable strength. In addition, by using basalt fiber, it is easy to absorb vibration, and it is possible to reduce vibration and noise generated inside the tunnel. Furthermore, since basalt fiber is made from basalt that exists in nature, even if it is disposed of after use, it does not need to be disposed of as industrial waste, and can be quickly decomposed and returned to soil.

The reinforcing effect of the concrete lining block (fiber reinforced concrete lining block) using reinforcing fibers will be described below. The fiber-reinforced concrete lining block obtained by disposing various high-strength new raw material fibers in the concrete is obtained by disposing reinforcing fiber materials in the concrete mixture and curing, thereby making up for the tensile strength that is a disadvantage of concrete. It has low strength or flexural strength, and at the same time, it can be endowed with elasticity, so that even if the deflection increases, it can prevent the concrete lining block from being damaged.

Fiber-reinforced concrete lining blocks can be produced by uniformly dispersing reinforcing fibers in a cement base material by the following method.

(i) A premixing method in which reinforcing fibers are molded into a three-dimensionally randomly dispersed state in a cement-based base material.

(ii) A jetting method in which reinforcing fibers are molded into a two-dimensionally randomly dispersed state in a cement-based base material.

(iii) A method of forming reinforcing fibers into a net-like or sheet-like fibrous structure in a cement-based base material.

When the above method (i) is adopted, the mixing amount of reinforcing fibers that can be uniformly dispersed does not exceed 3% by weight, and the reinforcing effect is poor. In addition, if the blending amount exceeds 3% by weight, the fibers are easily entangled into discontinuous fiber blocks, etc., so even if the fiber blending amount is increased in this method, the product strength cannot be increased accordingly, and the forming operability may be reduced or the strength may be reduced. Inequalities Undesirable phenomena.

Compared with method (i), method (ii) can select the mixing amount of reinforcing fibers in a relatively wide range, but due to the supply pump and sprayer structure of cement-water slurry (concrete mixture), etc. Restriction, the amount of aggregate used and the particle size are limited, and a greater reinforcing effect cannot be obtained.

Method (iii) is the most reasonable method among the manufacturing methods of fiber-reinforced concrete lining blocks. It is possible to select the mixing amount of reinforcing fibers in a wide range, and the strength unevenness of the concrete lining blocks is less. There are also fewer restrictions, and the reinforcing effect of the reinforcing fiber is high.

As the reinforcing fiber used in the present invention, various known fibers can be used alone or in combination. Examples include alkali-resistant glass fibers, E glass ("no alkali glass") fibers, carbon fibers, aramid fibers, vinylon fibers, polyarylate fibers, etc., but are not limited thereto. Among them, alkali-resistant glass fibers that do not deteriorate under the action of alkali components in concrete and are relatively inexpensive are particularly preferable.

The above-mentioned reinforcing fibers can also be used as a fiber structure. The fibrous structure can be in any shape, for example, two-way fabrics such as leno fabrics, plain weave fabrics or mockleno weave (mockleno weave), three-way fabrics, orthogonal or three-way braids, knitted fabrics, etc., but It is not limited to this. Among them, bidirectional fabrics and orthogonal braids are preferable, which are easy to design in strength. Bi-directional fabrics are particularly preferred for use due to their high cross point strength. By changing the type of fiber used for each reinforcing fiber, the shape of the fiber structure, and the amount of fiber mixed, it is possible to control the failure mode of the concrete lining block.

The two-way fabric, the orthogonal weave, is preferably in the form of a lattice with 3mm to 30mm meshes capable of passing fine aggregate in concrete. The more fibers are added, the greater the reinforcement effect of the fiber structure on the concrete lining block, but at the same time the mesh spacing becomes smaller. Therefore, it is necessary to adjust the amount of fiber incorporation and the mesh spacing, and it is particularly preferable that the amount of fiber incorporation does not become too small and the fine aggregate can pass through 3 to 15 mm.

The amount of fiber mixed can be appropriately selected according to the magnitude of the required reinforcing effect and the type of fiber used, and is preferably 30 g/m ² to 350 g/m ² .

Attaches the resin that binds the intersection points in the fibrous structure. When the fiber structure reinforces a curved concrete body, since it must conform to the curved surface, it is preferable to attach a thermoplastic resin in order to provide flexibility. The thermoplastic resin can be adhered by any method, for example, a method of impregnating a solution or dispersion containing a thermoplastic resin in the fiber reinforcement by dipping, spraying or brushing, etc., but not limited thereto. As a preferable aspect, for example, the reinforcing fiber is immersed in a 10 to 99% by weight aqueous solution of a thermoplastic resin, taken out, and then dried at 60 to 200° C. for 0.5 to 10 minutes. The content of the thermoplastic resin is preferably 2 to 60% by weight, particularly preferably 5 to 20% by weight, based on the total weight of the fibers and the thermoplastic resin. The type of thermoplastic resin preferably has an acrylic or vinyl acetate resin having a high adhesive force with a cement base material as a main component.

In the present invention, an economical concrete lining block with excellent reinforcing effect can be obtained by using reinforcing fibers or fiber structures with high strength and flexibility according to the above method.

Description of drawings

Fig. 1 is a perspective view of a tunnel using concrete lining blocks of the present invention.

Fig. 2 is an oblique view of the concrete lining block of the present invention.

Fig. 3A is a plan view of a reinforcing sheet mixed in the concrete lining block of the present invention.

Fig. 3B is a plan view of the network fiber structure mixed in the concrete lining block of the present invention.

Figure 4 is an oblique view of an embodiment of the concrete lining block of the present invention.

Figure 5 is an oblique view of an embodiment of the concrete lining block of the present invention.

Figure 6 is an oblique view of an embodiment of the concrete lining block of the present invention.

Figure 7 is an oblique view of an embodiment of the concrete lining block of the present invention.

Detailed ways

Next, various embodiments of the concrete lining block of the present invention will be described with reference to the drawings.

(first implementation)

After the tunnel is excavated by a shield excavator, concrete lining blocks 2 constituting the lining body 1 are installed in the excavated hole for construction. As shown in FIG. 1 , a plurality of concrete lining blocks 2 are arranged around the excavation hole to form a ring shape, and the lining blocks are arranged in sequence along the length direction of the excavation hole to form a cylindrical lining body 1 .

In Fig. 2, symbol 3 is an interface part, which is used to connect the concrete lining blocks 2 with bolts.

The cuboid-like shape of the concrete lining block 2 is bent into an arc shape, and steel bars (not shown) are buried inside as required. Reinforcing fibers are mixed into the concrete lining blocks 2 . As the reinforcing fiber, alkali-resistant glass fiber, E glass ("no alkali glass") fiber, carbon fiber, aramid fiber, vinylon fiber, polyarylate fiber, etc. can be used. The reinforcing fibers may be either short fibers or long fibers, but short fibers that are easy to mix are preferred in order to obtain uniform strength. The orientation of the reinforcing fibers is also an important factor in increasing the strength. The concrete lining block 2 must have sufficient strength to resist the earth pressure load from the outside. In order to resist the tensile stress generated on the inner peripheral surface side of the tunnel, it is preferable to arrange reinforcing fibers along the circumferential direction near the inner peripheral surface 2a of the concrete lining block 2. .

With the above configuration, since reinforcing fibers are mixed into the concrete, the strength of the concrete itself can be increased, so that the strength of the concrete lining block 2 can be increased without increasing the density of steel bars disposed inside or using larger diameter steel bars.

In the examples shown in Fig. 1 and Fig. 2, the example of the concrete lining block 2 that is suitable for bending the shape of the quasi-cuboid into an arc shape is given for description, but the shape of the concrete lining block 1 is not limited to the above-mentioned shape, for example , it is also possible to use a hexagonal plate-shaped lining block or a trapezoidal plate-shaped lining block formed by tapering on both sides.

(Second implementation)

A second embodiment of the present invention is shown in FIGS. 3A , 3B and 4 . In the above-mentioned second embodiment, as shown in Fig. 3A and Fig. 3B, the reinforcing fiber is woven into a thin sheet or a mesh in advance to make a reinforcing sheet 10 or a mesh-like reinforcing sheet (fibrous structure). )11, used in the form of fiber structures.

The reinforcing sheet 10 does not have to be in the form of a cloth that is regularly and accurately woven, and may be in the form of non-woven fabrics or the like in which fibers are arranged irregularly.

As an example of the arrangement of the reinforcing sheet 10 or the mesh-shaped reinforcing sheet 11 in the concrete lining block 2, as shown in FIG. . However, FIG. 4 only shows the case where only the surface portion on the inner peripheral surface side is buried. It is not necessary to embed in both the inner peripheral surface 2a and the outer peripheral surface 2b of the concrete lining block 2, and may embed only in either side. When embedding in either surface, it is preferable to embed on the side of the inner peripheral surface 2a exposed in the tunnel. The reason for this is to prevent cracks from appearing on the inner peripheral surface side of the tunnel that can be visually observed by the user.

As mentioned above, when the reinforcing fiber is used in the form of a fibrous structure such as the reinforcing sheet 10 or the net-like reinforcing sheet 11, it can be concentrated and arranged at a predetermined position where reinforcement is most needed, and the Compared with the case where the above-mentioned reinforcing fiber is uniformly mixed into the concrete for reinforcing treatment, it is possible to focus on strengthening the strength of a predetermined part and perform effective reinforcing treatment.

In particular, when the reinforcing sheet 10 or the reinforcing sheet 11 is embedded in the surface portion of the concrete liner block 2, cracks that tend to occur on the surface portion can be prevented.

As another arrangement example of the reinforcement sheet 10 or the mesh-like reinforcement sheet 11 in the concrete lining block 2, as shown in Fig. 5 and Fig. 6, it is embedded in the corner formed by the intersecting two faces of the concrete lining block 2. Section 13. That is, as shown in FIG. 5, the corner portion 13a (13) formed by the intersection of the inner peripheral surface 2a and the side surface 2c of the concrete lining block 2, the corner portion 13b (13) formed by the intersection of the outer peripheral surface 2b and the side surface 2c, and the side surface 2c , 2c and all the corners 13 such as the corners 13c (13) formed by the intersection between the units; or as shown in Fig. Part 13a (13) place is buried.

The corners of the concrete lining block 2 have more chances of conflict with other concrete lining blocks 2 or tools, or even machines, and "defects" are prone to occur. However, as described above, when the reinforcing fiber is formed into the reinforcing sheet 10 or the network-shaped reinforcing sheet 11 and then embedded in the corner portion 13 of the concrete lining block 2, the corner portion 13 can be prevented from being “broken”.

When embedding fibrous structures such as reinforcing sheets at the corners 13 of the concrete lining block 2, as shown in FIG. The portion that the user can visually observe, that is, the corner portion 13a of the inner surface 2a exposed to the inside of the tunnel, is "defected", and the "defect" of the portion that the user can observe can be prevented at a low cost.

Furthermore, as an example of the arrangement of the reinforcement sheet 10 or the mesh-like reinforcement sheet 11 in the concrete lining block 2, as shown in FIG. . In particular, the structure shown in FIG. 7 embeds reinforcing sheets 10 or net-shaped reinforcing sheets 11 only in the corner portion 15 formed by intersecting three faces of the concrete lining block 2 toward the inner peripheral surface 2a side.

Thus, as long as the reinforcement sheet 10 is only embedded in the corner 15 formed by the intersection of three sides in the concrete lining block 2, it is possible to focus on protecting the corner 15 formed by the intersection of three sides that is most likely to be "defected" and to use a relatively low cost. Price prevents "breakouts" from happening.

As the reinforcing fiber, the above-mentioned alkali-resistant glass fiber, E glass ("no alkali glass") fiber, carbon fiber, aramid fiber, etc. can be used, and basalt fiber can also be used.

Table 1 shows the comparison results of the physical properties of basalt fiber and glass fiber.

Table 1 parameter Basalt fiber glass fiber technical nature usable temperature ℃ -200～+700 -60～+450 Sintering temperature ℃ 1050 600 Thermal Conductivity kcal/℃ 0.027～0.033 0.029～0.035 physical properties density kg/ ^m3 2800 2540 hygroscopicity % 0.5 1 (read with a simple hygrometer) Vibration meter properties % 93～100 85～100 Elastic Modulus kg/ ^mm2 10000 7200 tensile limit MPa 1850～2150 1850～2150 100% Relative Humidity Resistance 0 day % 100 100 32 days % 92 74 64 days % 91 72 Change rate of tensile limit after heating (take the value at 20°C as 100) heating temperature 20°C % 100 100 200℃ % 95 92 400°C % 82 52 chemical properties Mass change rate (mass loss) after boiling in boiling liquid for 3 hours boiling liquid H ₂ O % 99.8(-0.2) 93.3 (-0.7) 2N NaOH % 88.9(-11.1) 83(-17) 2N HCl % 81.8(-18.2) 53.9 (-46.1) electrical properties Specific resistance (solute) Ω·m 1×10 ¹² 1×10 ¹¹ (Electric Resistance-to-Volume Ratio) Acoustic properties Standard acoustic insulation factor db 0.9～0.99 0.8～0.93

It can be seen from Table 1 that compared with glass fiber, the comparison result of tension shows that the strength of basalt fiber is higher than that of glass fiber. As can be seen from the comparison of chemical properties, basalt fiber is superior to glass fiber in acid and alkali resistance, so it can obtain long-term stable strength when used as a lining block. From the comparison results of elastic modulus (elastic rate), basalt fiber is easier to absorb vibration than glass fiber, and can reduce vibration and noise generated inside the tunnel constructed with concrete lining blocks. Moreover, basalt fiber is made of basalt that originally existed in nature. Even if it is discarded after use, it does not need to be discarded as industrial waste. It can be quickly decomposed and restored to soil, which is beneficial to the protection of the earth's environment.

Preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments. Additions, omissions, substitutions and other modifications can be made to the composition thereof within the scope not departing from the gist of the present invention. The present invention is not limited by the above description, but is limited only by the scope of claims.

Claims (5)

1, a kind of concrete lining segment is characterized by, and has sneaked into reinforcing fiber.

2, concrete lining segment as claimed in claim 1, wherein, described reinforcing fiber forms netted fiber structure (11).

3, concrete lining segment as claimed in claim 1, wherein, the reinforcement that is made of described reinforcing fiber is embedded in the surface portion (2a, 2b) of described concrete lining segment (2) with thin slice (10).

4, concrete lining segment as claimed in claim 1, wherein, the reinforcement that is made of described reinforcing fiber is embedded in the corner angle portion (13) of described concrete lining segment (2) with thin slice (10).

5, as each described concrete lining segment of claim 1～4, wherein, described reinforcing fiber is a basalt fibre.

Images