JPH07116681B2 - Telescopic joint material that also serves as a formwork - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a stretch joint material that also serves as a concrete placing formwork, and requires, for example, a concrete slab for concrete paved roads and other formwork and stretch joints. Used for concrete construction.

[Conventional technology]

Insulating concrete, waterproof concrete, various lightweight concrete, and other concrete that have large drying shrinkage, thermal expansion, thermal contraction, etc., and also absorb expansion and contraction sufficiently for concrete structures made of concrete material with low mechanical strength A general method is to construct flexible, highly elastic stretch joints at regular intervals to form one structure.

[Problems to be Solved by the Invention]

By the way, the expansion joint material used conventionally does not have the rigidity that can stand alone and can endure concrete pouring. For this reason, the joints will become partitions, and the formwork will be installed with rigidity that can withstand concrete pouring, and after the concrete has been cured and the required curing period has passed, the formwork will be removed. Stretch joints are attached with nails and adhesives, and then concrete in the adjacent block is placed.

Alternatively, set the formwork, attach expansion joint material to the inside by some method, then pour concrete,
After a required curing period, a method is adopted in which only the formwork is removed, the expansion joint material is attached to the side surface of the hardened concrete, and then the concrete of the adjacent block is placed.

However, according to these methods, “form installation → concrete placement → curing → removal of form → installation of expandable / contracting index material → installation of adjacent blocke formwork” or “formwork → installation of elastic index material → concrete placement → curing → It is necessary to repeat the cycle of work such as removing the formwork → installing the formwork of the adjacent block, and continuous construction of adjacent blocks is not possible, resulting in problems such as a longer construction period and reduced work efficiency. is there.

In addition, as shown in FIG. 3, the blocks on which the concrete 12 is placed in advance are every other block. In such a staggered construction, the concrete is placed on the preceding block.
When the curing is completed, there is no choice but a working place and a material storage place for placing concrete in the trailing block, so that there is a problem that the concrete surface of the preceding block is damaged. In FIG. 3, 11 is a stretch joint material and 13 is leveled concrete.

The present invention is intended to solve the above-mentioned problems in the prior art.

[Means for Solving the Problems]

As shown in FIG. 3, a stretchable joint material 1 also used as a formwork of the present invention has a core material 2 which is a plastic plate or a metal plate having strength as a concrete placement formwork, arranged at the center thereof, and has a predetermined shape on both sides thereof. Plate-shaped semi-cured plastic foam 3
Are bonded together with a bonding material 4.

As the plastic plate or the metal plate of the core material 2, one having a large rigidity and excellent durability and weather resistance is used, and one which is as thin as possible is used within a range in which the rigidity and strength required for the formwork are retained. To be done. As the plastic plate, a hard polyvinyl chloride plate, a fiber reinforced plastic plate or the like is used, and as the metal plate, an anticorrosion-treated iron plate or stainless plate is used.

The semi-rigid plastic foam 3 is a material having the required shrinkage amount and resilience and excellent water resistance, durability, and weather resistance. Among the commonly used stretch joint materials, soft plastic foam and hard plastic foam have problems such as required plate thickness, ease of shrinkage, resilience, and durability against repeated shrinkage and restoration. As the semi-rigid plastic foam 3, polyethylene foam, polypropylene foam, semiconductor polyvinyl chloride foam or the like is used.

An adhesive, a pressure-sensitive adhesive, a double-sided tape, or the like is used as the bonding material 4, and the optimum material is selected in view of the compatibility between the core material 2 and the semi-rigid plastic foam 3 to be bonded.

[Action]

By using the expandable joint material 1 that also serves as the mold of the present invention, there is no need to remove the mold or install an expandable joint material separate from the mold. As a result, it is not necessary to perform staggered construction as shown in FIG. 3, and concrete 7 of adjacent blocks can be poured simultaneously and continuously as shown in FIG. In addition, by adjusting the top surface of the expansion joint material 1 that also serves as the formwork to be the height of the finished surface of the concrete 7, a finishing scraping plate of the type that can be placed and moved on the top surface of the joint material 1 that also serves as moldwork is used. It is possible to effectively finish the surface after placing concrete.

The concrete 7 cast on both sides of the mold joint expansion / contraction joint material 1 of the present invention is adhered and hardened to the semi-cured plastic foam 3, and the semi-cured plastic foam 3 flexibly expands and contracts following the expansion and contraction of the concrete 7. However, it does not peel off and sufficiently closes the joint. Since a thin plate is used as the core material 2 as much as possible, the function of both the formwork and the expansion joint material is to be exerted by the expansion joint material 1 having the same thickness as that of the conventional expansion joint material. You can

〔Example〕

Next, as an example, an experimental construction example using the stretchable joint material 1 of the present invention that also serves as a mold will be described.

The stretch joint material 1 also used as a formwork uses a 3 mm thick cured polyvinyl chloride plate as the core material 2 and a 5 mm thick plate-like polyethylene foam (33 kg / m ³ ) as the semi-rigid plastic foam 3. An adhesive for adhesion processing of polyethylene foam was used as the bonding material 4. Using this formwork / expandable joint material 1, while forming stretch joints at intervals of 3 m in length and width, lightweight concrete 7 having a thickness of 50 mm was continuously poured.

In the actual construction, as shown in FIG. 2, fixing clips 5 are fixed at predetermined positions on the leveling concrete 8 with a nail or the like at intervals of about 1 m, and the expandable joint material 1 that also serves as the formwork is attached to the assembly and assembled. A concrete pouring span was formed. A wire mesh 6 was arranged therein as a reinforcing bar and a lightweight concrete 7 was placed therein.

〔The invention's effect〕

The stretchable jointing material of the present invention, which also serves as a formwork, has both a function as a formwork for placing concrete and a function as a stretchable joint, so that it has hitherto been called “formwork installation → concrete placement → curing → formwork”. Work that required a process such as removal → expansion and contraction index material installation → adjacent block formwork installation or "formwork installation → expansion and contraction index material installation → concrete placement → curing → formwork removal → adjacent block formwork installation" Can be shortened to the process of “formwork → (automatically installing expansion joints) → concrete placement”. Moreover,
It becomes possible to cast concrete in adjacent blocks continuously at the same time. In addition, the semi-cured plastic foam adheres to the concrete on both sides and expands and contracts, sufficiently closing the joints. As a result, the work can be significantly shortened as compared with the conventional construction method, and the two operations of the formwork installation and the expansion joint material installation can be integrated into one work, which improves the work efficiency and significantly reduces the cost.

[Brief description of drawings]

FIG. 1 is a perspective view in which a part of the expandable joint material used also as a mold of the present invention is cut away, and FIG. 2 is a partial view of the construction of a concrete slab using the expandable joint material used also as a formwork of the present invention. FIG. 3 is a perspective view with a cutout, and FIG. 3 is a perspective view showing a construction state in a conventional example. 1 ... Expandable joint material also used as formwork, 2 ... Core material, 3 ... semi-hard plastic foam, 4 ... Joining material, 5 ... Fixing clip, 6 ... Wire mesh, 7 ... Concrete, 8 ... Leveled concrete.

Claims (1)

[Claims] 1. A formwork also characterized in that a plate-shaped semi-rigid plastic foam having a predetermined thickness is adhered to both sides of a core material which is a plastic plate or a metal plate having strength as a formwork for concrete pouring. Expansion joint material.