JP5711474B2 - Sheet for block mat and block mat using the sheet - Google Patents

Description

  The present invention relates to a block mat sheet suitable for use in a construction block mat for preventing surface erosion and a block mat for soft ground reinforcement.

Conventionally, revetment or slope protection work, for example, leveling and solidifying the soil surface to be protected, laying a filter, stacking chestnuts, and then putting a concrete block while applying cement mortar on the top surface I was stuck.
However, such a construction method has the disadvantages that it takes time and effort, and the construction period is prolonged, and a skilled worker is required for pasting concrete blocks.

  Therefore, in order to eliminate these disadvantages, a surface erosion prevention mat with a concrete block bonded to a sheet material such as a woven cloth is produced at the factory in advance, and this mat is laid on the slope to be protected. Has been disclosed (see Patent Document 1 below). In this construction method, an adhesive is used to bond the concrete block and the sheet material. When an epoxy resin or the like is used as the adhesive, it can be bonded and fixed in a few hours by heat treatment. On the other hand, as described in Patent Document 2 below, the sheet is pressed against an uncured concrete block, and a part of the concrete is infiltrated between the fibers of the sheet, and the concrete is solidified in this state. In order for concrete to solidify completely, curing for about one week is required. Therefore, it can be said that the idea related to the mat for preventing surface erosion described in Patent Document 1 is excellent in productivity in that the adhesive solidifies in a short time.

  However, in the adhesive method mat as described in Patent Document 1, when the adhesive strength between the sheet material and the concrete block is low, when the block mat is laid on the site, both ends of the mat are not gripped. When it is unavoidable to suspend it depending on the situation, there is a problem that threatens safety at the time of laying construction such as the concrete block peeling off from the sheet material.

  Conventionally, in order to stabilize the soft ground, the dredging method (by combining logs with soft logs to disperse the loading load) and the cobblestone foundation method (laying a lot of cobbles on the soft ground, using a vibrator, etc.) Construction method suitable for shallow soft ground with ground restraint such as compaction and dispersion of loading load, and pile net construction method (prepared piles such as wood, concrete, steel, etc., to the appropriate depth) There is a construction method suitable for deep soft ground, such as connecting pile heads with a connecting material such as a rope, and laying a civil engineering sheet on the top of the pile. The dredging method and the cobblestone foundation method are methods suitable for shallow soft ground, but there are problems that support and restraint with the shallow ground are low and installation is troublesome. On the other hand, the pile net method is suitable for the deep soft ground method, but the support constraint of the deep ground is high, but there is a problem that the load distribution of the shallow ground is weak. There was a problem that there was no product that had both heavy dispersion.

In order to solve such a problem, the following Patent Document 3 includes a plurality of reinforcing blocks in which a projecting tip portion and a flat top surface are formed in order to reinforce the ground and restrain deformation. ,
A ground reinforcing mat is proposed, comprising: a sheet in which the plurality of reinforcing blocks are aligned and integrally bonded or fixed to the top surfaces of the plurality of reinforcing blocks by an adhesive body or a fixing body. ing.
In the same manner as the adhesive method mat described in Patent Document 1, the ground reinforcing mat may be suspended by gripping the sheet when laying the ground reinforcing mat. Strengthen the tensile strength in the longitudinal direction of the sheet to prevent the mat from breaking due to the tension applied to the seat when the reinforcing block is loaded and the external force such as swinging by heavy machinery and wind. Need to do. In Cited Document 3, this tensile strength is required to be at least twice the weight of the reinforcing block, but preferably more than four times in consideration of the strong external force such as the moving speed of the mat suspension heavy machine and wind. It is described that there is.

Japanese Utility Model Publication No. 51-9135 JP-A-54-93018 JP 2009-108660 A

  The problem to be solved by the present invention is that the above-mentioned mat for preventing surface erosion (adhesive method mat) or the mat for ground reinforcement is a problem that threatens safety at the time of laying construction such as the concrete block peeling from the sheet material. In order to avoid the occurrence of this, the adhesive force between the concrete block and the sheet material is increased to improve the safety when laying the mat.

As a result of intensive studies and experiments to solve the above problems, the present inventor discovered the following.
Taslan processed yarn is composed of core yarn and sheath yarn, and the core yarn is a straight yarn that takes on the strength of the Taslan processed yarn itself, while the sheath yarn is an entangled yarn wound around the outer periphery of the core yarn. If the yarn is excessively entangled, the filaments of the entangled yarn become loose. When such a taslan processed yarn is used as a fiber (yarn) constituting a fiber sheet in a mat for preventing surface erosion or a mat for ground reinforcement, a taslan processed yarn in a fiber sheet that is impermeable to soil and sand particles and has water permeability. The core yarn has a reinforcing effect, and the sheath yarn of Taslan processed yarn is directly laid on the ground surface, so that the sheath yarn increases the friction with the ground surface and exhibits an anti-slip effect. Furthermore, in such a block mat in which the sheet and the concrete block are bonded and fixed, the use of the taslan thread on the sheet causes the sheath thread of the taslan thread to be entangled well with the adhesive. The adhesive strength between the sheets is increased, and the safety when mats are laid is improved.

Based on the above findings, the present inventor has completed the following invention.
[1] A block mat woven or knitted sheets made of fiber sheet of sediment particles impervious having water permeability and flexibility, in some or all of the vertical Direction of the fiber sheet, crimp ratio 7% following Tasuran yarn is being woven or knitted overcame weft 3 or more, and, the block mat withstand tensile elongation at break of the fiber sheet is equal to or less than 25% Woven fabric or knitted sheet.

[2] A work block mat for preventing surface erosion, in which a concrete block is bonded and fixed to the woven fabric or knitted block mat sheet according to [1].

[3] A ground reinforcing block mat in which a reinforced concrete block is bonded and fixed to the woven or knitted block mat sheet according to [1].

  According to the present invention, the core thread of the taslan-processed yarn has a reinforcing effect, and further by laying the sheath thread of the taslan-processed thread directly on the ground surface, this sheath thread increases the friction with the ground surface, and the anti-slip effect is exhibited. Furthermore, in a block mat in which such a sheet and a concrete block are bonded and fixed, the sheath thread of the taslan-processed yarn becomes entangled with the adhesive, resulting in an increase in the adhesive force between the concrete block and the sheet. Safety is improved.

Schematic diagram of laying block mat for preventing surface erosion for slope protection. The photograph replaced with drawing of one example of the construction block mat for surface erosion prevention which adhered and fixed the concrete block on the construction sheet for surface erosion prevention. It is the photograph replaced with drawing of one example of the construction sheet for ground surface erosion prevention. The upper photo shows a ground erosion prevention work sheet according to the present invention, in which a Taslan processed yarn is used as a reinforcing yarn and the distance over the weft yarn is six. The photograph below shows a conventional surface erosion prevention work sheet using a thread that has not been subjected to Taslan processing and has three intervals over the weft thread. Schematic when the work block mat for preventing surface erosion is suspended by heavy machinery for laying. It is a perspective view from the lower part of the block mat for soft ground reinforcement.

The block mat sheet according to the present invention, for example, the ground erosion prevention work sheet, has good water permeability to the ground surface through the sheet, and possesses an erosion preventing function for preventing the earth and sand from flowing out by the sheet. A sheet having a filter effect is used. Here, the filter effect is an effect of preventing permeation of earth and sand while having water permeability. As the sheet having such an effect, a sheet having a mesh such as a woven fabric or a knitted fabric is preferably used. Although the degree of filter effect and water permeability can be controlled by the size of the mesh, those having a mesh of 1 mm ² or less are preferably used in the present invention.

  Furthermore, if the sheet according to the present invention is composed of synthetic fibers, it is excellent in flexibility, so it can be used for soft ground that is well-adapted to the ground surface, has good adhesion, and has the possibility of uneven settlement. . Accordingly, the material for the surface erosion prevention work sheet of the present invention includes synthetic fibers, polyethylene fibers, polypropylene fibers and other olefin fibers, polyamide fibers, polyester fibers, polyvinylidene chloride fibers, polyvinyl alcohol fibers and other general purpose fibers, carbon fibers , Functional fibers such as aromatic polyamide, natural fibers, regenerated chemical fibers, and the like. These may be used alone or in combination. The sheet may be woven or knitted as long as it has a mesh, but in the case of a block mat to which a concrete block is bonded and fixed, a lifting operation is performed when laying, so that the displacement of the block due to the elongation of the sheet is prevented. In order to reduce it, it is desirable to use a woven fabric with less elongation.

  When used as a concrete block mat, the mat is suspended by gripping both ends in the mat length direction when laying, so the sheet strength is required so that the sheet is not damaged by the load of the concrete block. In order to reduce the block displacement, it is desirable that the sheet has a low tensile elongation at break and is difficult to stretch.

  In addition, when using as a concrete block mat, a concrete block is placed on the sheet, and the individual concrete block and the sheet are bonded and fixed with a curable adhesive. Therefore, in order to ensure the safety of laying and maintain the accuracy after laying, high adhesion strength is required for bonding between the concrete block and the sheet.

Thus, in order to satisfy the requirements of high strength, low elongation, and high adhesive strength when used as a concrete block mat, in the present invention, as a fiber sheet, in the woven fabric and knitted fabric having the filter function, A woven or knitted fabric in which Taslan processed yarn is woven or knitted is used as the reinforcing yarn.
Although all of the yarns constituting the woven fabric or knitted fabric can be made into a taslan processed yarn, usually a part thereof is made into a taslan processed yarn. The taslan yarn can be used in one or both of the vertical direction and the horizontal direction, but is preferably used in the vertical direction in order to ensure the strength during construction of the block mat.

Taslan processed yarn has a structure in which a sheath yarn is entangled by forming a loop or a slack around a core yarn, and usually two or more multifilaments are mixed with air and / or water. It is obtained by fluid treatment.
As a specific example of sheet production according to the present invention, a polyethylene monofilament of 330 dtex in the sheet length direction and 660 dtex in the width direction is 52 / inch in the length direction and 25 / inch in the width direction to form a mesh. It is constructed and taslan yarn is woven into 6 pieces / inch for longitudinal reinforcement and high adhesiveness. As the Taslan processed yarn, two high-strength polyester fibers having a core yarn of 1670 dtex 192 filaments and 1100 dtex / 192 filaments of high-strength polyester fibers processed as a sheath yarn by 20% overfeed were used.

  In order to improve the high adhesiveness and anti-slip property in the Taslan processed yarn, the number of filaments of the sheath yarn is preferably as large as possible, preferably 65 or more. The higher the tensile strength of the taslan yarn, the better, and it is preferably 7 cN / dtex or more. The higher the overfeed rate of the sheath yarn in Taslan processing, the better. However, the overfeed rate is preferably about 15 to 30% so as not to cause a standstill during sheet production. A combination of the number of filaments, tensile strength, overfeed rate, and the like is allowed if a synergistic effect is exhibited even if it is outside the respective preferred ranges described above.

Further, the number of weaving taslan yarns is 6 / inch in this embodiment. However, increasing the number of weaving yarns increases the strength of the sheet and is preferably 3 / inch or more.
When used as a concrete block mat, the mat is suspended by gripping both ends in the mat length direction when laying, so the sheet strength is sufficient to prevent the sheet from being damaged by the block load. Considering the mat rotational movement, etc., it is necessary to expect a safety factor of about 5 times or more. For example, when 8 m of a 20 cm square 5 kg concrete block is bonded and fixed to the sheet, the tensile strength at break of the sheet is preferably about 49 kN / m or more.

  As described above, when used as a concrete block mat, it is preferable that the tensile elongation at break of the sheet is low. As a method of reducing the tensile elongation at break of the sheet, there is a method of reducing the crimp rate of the taslan processed yarn that is the reinforcing yarn. That is, when the reinforcing yarn is put in the longitudinal direction, the crimp rate can be lowered and the tensile breaking elongation rate can be lowered by increasing the interval (number) of overcoming the yarn in the width direction. For example, specifically, the crimp rate is 5.9% and the tensile elongation at break is 3% when the distance over the ride is 3, but the crimp rate is 4.5% when the distance is over 6 The elongation is 18%.

  When used as a concrete block mat, the tensile elongation at break of the sheet is preferably 25% or less in order to reduce the block displacement, the crimp rate is 7% or less, and the interval to get over is 3 or more. Is preferred.

There are no particular restrictions on the distance in the longitudinal direction and the width direction of the concrete blocks that are adhesively fixed to the sheet, but it is usually preferable that the distance is about 30 mm or less and the blocks are arranged almost continuously.
For the adhesive fixation, an inorganic or organic adhesive or an adhesive mixed with these is usually used. As the inorganic adhesive, for example, a hydraulic cement composition such as mortar or concrete can be used. Organic adhesives that use thermosetting resins such as epoxy resins, urethane resins, acrylic resins, silicone resins, epoxy acrylate resins, and phenol resins, thermoplastic resins such as polyamide resins, polyester resins, and ethylene vinyl alcohol resins And those using synthetic rubber such as styrene butadiene rubber, chloroprene rubber, butyl rubber, etc., and an epoxy resin excellent in strength and curability is preferably used.

On the other hand, as shown in FIG. 5, the ground reinforcing mat of the present embodiment includes a plurality of reinforcing blocks and a sheet for integrally bonding and fixing the reinforcing blocks. The reinforcing blocks are arranged in alignment with the sheet and are integrally fixed by an adhesive body or a fixing body.
The reinforcing block has a conical shape at the lower side in contact with the ground and a cylindrical shape at the upper side. The material of the reinforcing block is the same material as the upper part in the lower part or the upper part other than the tip part when there is a fear that the upper part may be missing because there is a hard stone on the soft ground. Different. Specifically, the upper portion is made of concrete that is strong in compressive force, and the lower end portion is made of an elastic metal or resin that has strong tensile force.
The block mat sheet described above with respect to the ground erosion prevention work sheet can also be used for the ground reinforcing block mat.

  Tensile strength and elongation are measured by the JIS L1096 labeled strip method, and the crimp rate is marked on the sheet at intervals of 1 m, the measured yarn is unwound from the sheet, and the marking interval under the initial load Was obtained by dividing by 1 m.

  The 180 ° peel adhesive strength of the sheet using the taslan processed yarn was measured with a tensile tester.

  The static friction coefficient of the sheet using Taslan processed yarn against pure sand was measured in a friction test under a 5 kg / 20 km square load.

Manufacturing sheet for surface erosion prevention construction sheet Polyethylene monofilaments of 330 dtex in the length direction and 660 dtex in the width direction are formed in a mesh shape with 52 pieces / inch in the length direction and 25 pieces / inch in the width direction. In order to reinforce in the longitudinal direction and high adhesion, Taslan yarn was woven into 6 pieces / inch. As the Taslan processed yarn, two high-strength polyester fibers having a core yarn of 1670 dtex 192 filaments and 1100 dtex / 192 filaments of high-strength polyester fibers processed as a sheath yarn by 20% overfeed were used.
The obtained sheet is a sheet in which the taslan processed yarn, which is a reinforcing yarn, passes over every six yarns in the width direction, the tensile breaking strength is 84 kN / m, the tensile breaking elongation is 18%, and the crimp rate is 4 .5%. The mesh of this sheet was 0.1 to 0.4 mm in the sheet width direction and 0.4 to 0.8 mm in the sheet length direction.

Manufacture of surface erosion prevention work block mat Arbitrary number of concrete blocks are placed on the above sheet, and each concrete block and the sheet are bonded and fixed with a curable adhesive, 1.5 m wide and 8.8 m long A block mat for preventing surface erosion was manufactured. On the sheet of 1.5 m width and 8.8 m length, cement, fine aggregate, coarse aggregate, water-mixed concrete is a square trapezoidal shape with a width of 20 cm, a length of 20 cm, and a height of 10 cm, and a weight of 5 kg. 6 concrete blocks that were immediately demolded and dried were arranged in 6 rows in the sheet width direction and 40 rows in the length direction, and epoxy resin (main agent: hardener = 2: 1 mixed) between each concrete block and the sheet ) 5 g was pressure-bonded to the concrete block surface at four points, and was adhesively cured and fixed.

  As a result of measuring the 180 ° peel adhesive strength of the sheet using the taslan processed yarn by the above-mentioned adhesion with a tensile tester, it is 160 N per 1 cm of the adhesive width, while high strength polyester of 1670 dtex 192 filament instead of the taslan processed yarn The 180 ° peel adhesive strength with the same adhesive formulation in the Taslan processed yarn-free sheet woven with two fibers was 98 N per 1 cm of adhesive width. That is, the taslan-processed yarn-using sheet has a 1.6 times higher adhesive strength than the taslan-processed yarn-free sheet, and the mat hanging operation can be performed with confidence even in the slope laying operation.

  In addition, the static friction coefficient of the taslan-processed yarn-use sheet against the pure sand soil is 0.57 when measured in a friction test under a 5 kg / 20 km square load, while the taslan-processed yarn-free sheet has a static friction coefficient. Was 0.45. That is, the sheet using Taslan processed yarn has excellent anti-slip properties and improved mat stability on the slope.

  The block mat sheet according to the present invention is an easy-to-use anti-slip effect in the work block mat for preventing surface erosion, and improves the safety when laying the mat by increasing the adhesion between the concrete block and the sheet. In addition, it can be suitably used for a surface erosion prevention work sheet that can provide revetment, slope protection, and the like, and a surface erosion prevention work block mat using the same. Further, the present invention can also be suitably used for a ground block erosion prevention work block mat by increasing the adhesive force between the concrete block and the sheet to improve the safety when laying the mat.

Claims (3)

A block mat woven or knitted sheets made of fiber sheet of sediment particles impervious having water permeability and flexibility, in some or all of the vertical Direction of the fiber sheet, the crimp ratio of 7% or less said block mat woven Tasuran yarn of, it is woven or knitted to get over the weft 3 or more, and resistance to tensile elongation at break of the fiber sheet is equal to or less than 25% Or a knitted sheet. A work block mat for preventing surface erosion, wherein a concrete block is bonded and fixed to the woven fabric or knitted block mat sheet according to claim 1. A block mat for ground reinforcement in which a reinforced concrete block is bonded and fixed to the woven fabric or knitted block mat sheet according to claim 1.