JP3229381U - Post-construction anchor with hybrid bottom expansion plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a post-construction anchor with a hybrid bottom expansion plate which does not pull out by combining a metal system and an adhesive system. SOLUTION: As a metal anchor 1, a bottom expanding plate 4 having a diameter of 43 mmφ having a recess at the tip of JIS G3112 deformed steel bar D192 2 is welded to form an anchor that cannot be pulled out. As the adhesive anchor, after inserting the metal anchor 1, the main agent / curing agent of the resin adhesive such as evoxy resin is stirred and mixed in the gap until it becomes uniform, or a mixture of non-shrink mortar and water is mixed with a coking gun or the like. The hardened or solidified molded product 5 including the metal anchor 1 was integrated into a lump that could not be pulled out by spreading the hem. [Selection diagram] Fig. 3

Description

Regarding post-construction anchors used for joining buildings and installing equipment.

There are two types of post-construction anchors, metal type and adhesive type. For metal, use a hammer drill to drill a circular hole perpendicular to the concrete surface, insert a metal post-construction anchor, and then insert the core rod, internal cone, body, sleeve-driving method cone nut, taper bolt, double cone, Wedge-Tightening method This is a method of expanding the expansion part by either method to prevent the anchor from pulling out.
For other adhesive systems, after drilling, a capsule containing the main agent, hardener, and aggregate is inserted into the glass tube, and a capsule containing cement mortar is inserted into the paper tube, and a pointed full-threaded bolt is rotationally impacted or driven. The capsule is broken with, and the mixture of the main agent and the curing agent of the resin content is cured, or the mixture of cement mortar and water is solidified to fill the hole.

The expansion width of the conventional metal-based post-construction anchor is 2 mm or less, and there is a risk that the anchor will come off when wind pressure or vibration is constantly applied to the anchor that hangs a heavy ceiling or the like. Even in the case of the adhesive system of other methods, the mixture of the resin main agent, the curing agent, and the aggregate is insufficient in the rotation of all screw bolts. In addition, the hole is clogged with the residual material of the broken capsule and air, and the anchor may easily come off if the adhesive is slightly attached to the hole entrance. The anchor used in the 2012 Sasako tunnel ceiling board fall accident (9 dead) is an adhesive post-construction anchor, and the result of the accident investigation review committee's pull-out test shows that 9% has a pull-out resistance of 12.2 kN. It was less than, and some were up to 0 kN.

After inserting the metal-based post-construction anchor, the expansion width of the expansion part is as small as 0 to 2 mm regardless of whether it is driven or tightened, so the anchor may come off. The problem was solved by providing a circular bottom expansion plate 4 having a diameter larger than the diameter of the deformed steel bar 2 (about 20 mmφ in the case of D19). The larger the diameter of the bottom expansion plate, the wider the hem will prevent it from pulling out. On the other hand, there are restrictions on the size of the drill bit during drilling, and the maximum diameter of a domestic drill bit is 38 mmφ, and that of a foreign-made drill bit is 45 mmφ. Therefore, if the bottom expansion plate is a circular shape with a diameter of 43 mm and the thickness is 6 mm or more, the SS400 iron plate will not buckle in the tensile test. The shape of the recess 3 may be semicircular or square. For large diameter drilling, there is also a method using a core bit with diamond grains other than a drill bit.

After inserting the anchor muscle of the present invention, evoxy resin, evoxiacrylate resin-benzoyl peroxide, unsaturated polyester-benzoyl peroxide and other resin-based adhesives, a mixture of curing agents, or a mixture of non-shrink mortar and water Pour it into the gap and spread the liquid sufficiently so that no air remains. After the resin is hardened or the cement is solidified, the entire contents of the hole become a single mass molded product and strongly adhere to the wall of the hole. The anchor is completed because it has a wide hem and cannot be pulled out.

The anchor of the present invention is a hybrid type post-construction anchor that combines a metal system and an adhesive system, and is an anchor that has the advantages of both. If the tensile resistance is 100 kN or more and it is forcibly pulled out, it will be cut by the threaded part of the anchor muscle. An anchor that cannot be pulled out was obtained.

Plan view of post-construction anchor with hybrid bottom expansion plate of the present invention Explanatory drawing of the bottom expansion plate Construction explanatory view of the anchor of the present invention

As an anchor bar, a circular bottom plate 4 with a thickness of 10 mm and a diameter of 43 mm φSS400, which has four semi-circular recesses 3 at one end of a deformed steel bar length 175 mm specified by JIS G3112 SD345 D19 (diameter about 20 mm), is welded. The end 55 mm is threaded equivalent to M16. A hammer drill equipped with a 45 mmφ drill bit is used to drill a hole with an embedded length of 120 mm, and after sufficiently removing cutting chips, the anchor bar is inserted.

Take out the epoxy resin adhesive at a ratio of main agent / curing agent = 1/1, stir and mix with a hand mixer until it becomes uniform, and pour it into the gaps such as the anchor streaks and the walls of the holes so that no air remains. Similarly, in the case of non-shrink mortar, a mixture of mortar and water is poured into the gap. When the epoxy resin is cured or the mortar is solidified, the construction of the post-construction anchor with the hybrid bottom expansion plate of the present invention is completed.

1. 1. Post-construction anchor with hybrid bottom expansion plate of the present invention 2. Deformed steel bars 3. Concave (semicircular)
4. Expanded bottom plate 5. Cured synthetic resin or solidified non-shrink mortar

Claims (2)

A post-construction anchor with a structure in which a bottom expansion plate 4 having a recess 3 is welded to the tip of a deformed steel bar.
The bottom expansion plate 4 is a circular iron plate of SS400 having a thickness of 6 mm or more and a diameter of twice or more the diameter of the deformed steel bar 2. After inserting the anchor bar into the hole, the main agent of the resin adhesive such as epoxy resin, epoxy acrylate resin, unsaturated polyester resin, the mixture of the curing agent, or the mixture of non-shrink mortar and water is poured into the gap, and no air remains. Spread the liquid sufficiently. After the resin is cured or the cement is solidified, the entire hole contents become a single mass molded product, which strongly adheres to the hole wall. The structure of the post-construction anchor molded product with the hybrid bottom expansion plate that has become a mass.

Images