JPS62129408A - Jointing method for asphalt mat - Google Patents

Abstract

PURPOSE:To obtain wide sealing and show stable water-stop effect, by heaping up the end sections of asphalt mat sheets vertically, and by setting the band unit of water-swelling composition along the edge sections of the asphalt mat sheets. CONSTITUTION:So far as asphalt mat sheets used for the embankment and the other water works of a harbour, river, or the like are concerned, the end sections of the asphalt mat sheets 1 are vertically heaped up, and then along the edge sections of the asphalt 1, the band unit 2 of water-swelling composition is set. In this case, the band unit 2 may be made of welling polyurethane resin, swelling polyvinyl, the denatured substance of polyethylene oxide, styrene-maleic anhydride coplymer, or the like. By this organization, the bank unit 2 is pressed in the vertical direction by the mat sheets 1, and so when the band unit 2 swells, then it horizontally extends as shown by a dotted line a, and side sealing is obtained, and stable water-stop effect is shown.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for joining asphalt mats used for embankments of ports, rivers, and other water works.

[Conventional technology]

Asphalt mat is asphalt, stone powder (filler)
, sand, and crushed stone are precast on land to form a mantle, and such asphalt mat 1
As shown in Figure 2, this is a construction method that is installed on the foundation slope, slope, etc. of a hydraulic structure to prevent soil leakage, outflow, and scouring of the embankment body by using the watertightness and flexibility of the cloak. Construction methods are being used to increase the sliding resistance of embankments by applying them to the bottom of gravity-type structures. Figure 2 shows the case of leakage prevention of buried soil, in which 3 shows the embankment body, 4 shows the embankment as its foundation, and 5 shows the concrete block that protects the slope of the embankment 4.

Incidentally, the joints when the asphalt mats 1 are laid out will differ depending on the conditions of the construction site, but as shown in Fig.
) When pouring the mast/7ri into the joint by poking it, (C
) There are cases where a joint board is placed above or below the butted joint, and each has its advantages and disadvantages, but (b) is the best in terms of ease of construction.

However, the overlapping seam (a) also has the disadvantage of being weaker in strength than other joints. Therefore, special public service 1975-2
In No. 1778, an asphalt-based soft material is sandwiched between the ends of the asphalt mat, and the joints are then crimped to improve the adhesion of the overlapping joints.

The asphalt-based soft material used as this joint medium is preferably made by adding an appropriate amount of soft natural and synthetic polymers (including copolymers) to asphalt.
In particular, those containing a rubbery substance are said to be suitable.

[Problem that the invention seeks to solve]

The method shown in Japanese Patent Publication No. 50-21778 is to press the asphalt and the asphalt-based soft material as the joint medium, and this pressing requires a step of rolling with a roller or the like. It was extremely troublesome and time-consuming.

It is an object of the present invention to provide a method for joining asphalt mats that eliminates the disadvantages of the conventional examples and can be easily and effectively constructed without using pressure bonding operations such as rolling presses or adhesives.

[Means for solving problems]

In order to achieve the above object, the gist of the present invention is to sandwich a band of a water-swellable composition between the ends of the asphalt mats when the ends of the asphalt mats are overlapped to form a joint. It is.

[Effect]

According to the present invention, the strip sandwiched between the ends of the asphalt mat absorbs moisture in the ground or water and swells.

As a result, the bond with the asphalt mat becomes tight even without external pressure bonding, and a completely watertight structure can be obtained.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of the joining method of the present invention, in which reference numerals 1 and 1 indicate asphalt mats as described above.

In order to join this asphalt mat 1, the edges are overlapped vertically to form a seam. At this time, a band 2 of a water-swellable composition is placed along the edge of the mat 1, and this band The body 2 is sandwiched between the mats 1 and 1.

The water-swellable composition constituting the band 2 may include swellable polyurethane resin, swellable polyvinyl, etc.
Compositions based on water-swellable polymeric substances, modified polyethylene oxide, styrene-maleic anhydride copolymer, crosslinked polyvinylpyrrolidone, crosslinked acrylic acid-acrylamide copolymer, starch-acrylonitrile copolymer Possible examples include hydrolyzates of agglomerates and those created using polymeric substances of cellulose derivatives.

Suitable materials include compounds made of such a swellable substance as a main material and compounded with liquid rubber or other rubber materials, or compounds made of a synthetic resin relatively similar to rubber such as thermoplastic elastomer.

As for the construction procedure, the lower asphalt mat 1 is laid first, then the strips 2 are arranged a little deeper along its edge, and finally the edges of the upper asphalt mat 1 are overlapped.

When the bonded portion of the mat 1 is formed in this way, the band 2 is made of swellable polyurethane. Water is incorporated into the urethane molecular structure as hydrogen bonds, and the entire body swells. Since the strip 1 is held in the vertical direction by the mat 1, it spreads laterally as shown by the dotted line a, and a wide seal is obtained.Also, as water is taken in as described above, a stable water stop is achieved. It is effective and maintains stable physical properties even after swelling.

〔Effect of the invention〕

As described above, in the asphalt mat joining method of the present invention, a joint medium is used when overlapping the ends of the asphalt mats to form a joint, but this medium and the mantle are joined by rolling pressure using rollers. It is easy to install, requiring no work or adhesive application, and provides an effective water-stopping structure with great adhesion.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the asphalt mat joining method of the present invention, FIG. 2 is a vertical side view showing an example of how the asphalt mat is used, and FIG. 3 is an explanatory view showing an example of joining asphalt mats. . 1... Asphalt mat 2... Band of water-swellable composition 3... Embankment body 4... Embankment 5... Concrete flock Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] A method for joining asphalt mats, which comprises sandwiching a band of a water-swellable composition between the ends of the asphalt mats when the ends of the asphalt mats are overlapped to form a joint.