Anchors: their efficiency and varieties
A more recent acquisition for builders of steel plastic dowels, which are small in size, cheaply stand and firmly held. However, shortly plastic dowels begin to deform and no longer fix the fastening, especially for monolithic concrete walls, which simply do not hold dowels.
Therefore, the most reliable anchoring method was created - an anchor that can withstand loads, and, like an anchor, it clings into the cover, not allowing to break the fastening.
The anchor is not just consonant with the word "anchor", it is similar in functions to: holding the mechanism at the bottom of the hole.
Bolts are divided into two types by type of use:
- Synthetic. The principle of its operation is based on the use of a special glue capsule, which opens when the fixing bolt is screwed in and fastened directly when the adhesive is dried.
Minus the synthetic bolt: waiting when the glue dries.
Plus: suitable not only for monolithic walls, but for lightweight wall structures.
- Metallic. The principle of its action is that the metal sleeve, which is placed on the bolt, expanded or wedged during screwing on the thread.
Also these bolts have several divisions for types:
ü Shnipovaya. At the end of the anchor is a schnip( wedge), which expands the sleeve during its screwing into the hole. Instead of a wedge there can be a rod-beard, which wedges the sleeve, and then it is removed from the hole, where after the screw is screwed in. However, for carrying out this type of work, it is necessary to strictly observe the dimensions of the anchor and holes.
ü Clamping. The basis of its action is the opening of the binding lobes, which occurs when the middle part of the sleeve is twisted and deformed. It also has small slits along the entire length. These bolts are suitable for thin wall structures, for example, gypsum boards.
ü Hammered. This species is used without the use of special devices. The bolt case itself has soft edges, which during the drive into the hole begin to deform and abut the bottom. This leads to the fastening of the sleeve in the opening. A bolt is suitable for a monolithic wall and a wild stone, however, pay more attention to the accuracy of the depth and diameter of the hole.
ü Crushed( spread) - the most frequent method of fastening, which does not require a clear compliance with the depth and diameter of the hole. During screwing, it expands the sleeve from the rear, screwing a cone-like bushing into it. Bolts are used for brick and concrete walls.
Screwing of the anchor bolt: instruction
In order to fix the anchor with a quality one, it is necessary to purchase metal products with anti-corrosion coating, for example, M-30.
It should also be understood that each joint has its own parameters for the hole and the rate of applied force for screwing, which depends on the characteristics of the wall covering. For heavy concrete, the depth of the bolt is 8 cm, and the load is less than 7 kN.For thin concrete, these parameters are half the size.
In the instructions, we will consider in stages the fastening of the crushed( spread) anchor into the concrete wall.
Step 1: Determine the length of the
bolt The walls are often covered with a finish, for example plaster. To bolt the bolt well in the wall, it should be placed at a depth of more than 5 cm. Therefore, determine the length of the anchor sleeve for the thickness of the plaster.
Step 2: Determination of the required hole diameter
It is necessary to monitor the diameter of the hole for the anchor, since its accuracy depends on the forces applied to screw the sleeve. The hole must be such that the sleeve comes in tightly and strictly perpendicular. As for the depth of the hole, it should be longer than the bolt length by several millimeters.
Step 3: Marking the hole and punching it
The holes for the bolts should be made as accurate as possible after installation, it can not be pulled out. Then drill a hole and clean it of dust and debris. You can clean it by vacuuming, blowing with a rubber pear or brush.
Step 4: clogging the anchor
Insert the anchor into the hole made with a hammer. This must be done slowly and with progressive movements. After the nut or the head of the sleeve is at the surface of the wall, proceed to twist. When twisting after two revolutions, more effort should be applied. The box can indicate the number of twists and for this purpose it is better to use a torque wrench.
Please note, for thin, brick or foam concrete walls, it is best not to tighten the anchor to the stop.
Step 5: Checking the accuracy of the
dipping When screwing the bolt very often, the nut or cap falls into the top layer of the plaster. It is better to tighten the nut into the wall, but the hat should be left exactly at the surface of the wall. The video in the next tab shows how to properly anchor the anchor to the concrete wall.
