What are the usual anchors, we have already written. The main difference between chemical fasteners is the use of a special adhesive. This does not mean that anchor rods, threaded rods, steel sleeves, and reinforcing bars are not used. The chemical composition goes in addition to the metal part, making it even more reliable to fix the part to the base.
In general, a chemical anchor is a special cartridge or ampoule with an adhesive inside. The cartridge is almost identical to the familiar tubes for silicone and other sealants. In addition, there is a stud, female threaded bushing or rebar, traditionally made from stainless steel or galvanized steel. The result is a two-in-one mount.
Manufacturers often keep the exact composition of the mixture for chemical anchors secret, this is a commercial secret of the companies. However, the adhesive mass necessarily contains synthetic, artificial resins, a hardener, other organopolymers, quartz sand, and cement acts as a binding mixture.
The principle of using a chemical anchor is actually simple. It is required to buy an adhesive in a cartridge, use a special gun to squeeze it out according to the principle of using many sealants, as well as the metal element itself, the anchor itself. The hole for inserting the chemical anchor is prepared in advance, then the adhesive is squeezed into it, after which a metal rod is inserted.
If you bought an ampoule for a chemical anchor, then one container goes to one hole. The ampoule is simply inserted into it, then a metal rod is screwed in, it crushes it, the adhesive is released outward. This process is even easier than using a cartridge, which requires a special pistol to squeeze the mixture out..
The glue in the hole polymerizes, hardens, which provides the most reliable anchor and structural material adhesion.
Benefits of using chemical anchors:
- Fastening strength. This is the main plus. An anchor with a chemical composition in its strength characteristics is much superior to conventional “colleagues”. The tensile strength increases by 2.5 times! This allows the use of chemical anchors for the creation of very complex structures and especially reliable fastenings, including in conditions of vibration, static and dynamic loads. In simple terms, a chemical anchor is able to fix everything literally tightly.
- Long service life. Reliable fastening of a chemical anchor can last over 50 years.
- When installing a chemical anchor, tensile stresses do not occur in concrete.
- The hole for the metal mount is automatically sealed with the adhesive mixture itself.
- Resistant to weathering, corrosion and chemicals.
- Can be used even under water, there are special formulations for this purpose.
- Simple installation. Even without experience of such work, you can independently install a chemical anchor where necessary..
- Such fasteners do not cause mechanical stress on the walls of the hole, because there is no bursting. Therefore, the chemical anchor is excellent for use on the edges of various structures, including stair railings and parapets..
We wrote about the features of aerated concrete blocks when building a house, mentioning as one of the disadvantages of this material the difficulty of installing fasteners, for example, to hang a storage water heater on the wall. So – chemical anchors are ideal for fixing anything on a wall of aerated concrete blocks.
In addition, they are excellent when used with other porous building materials, including foam concrete, hollow bricks, porous ceramic blocks. In general, a wide range of applications is an undeniable advantage of a chemical anchor..
The disadvantages of a chemical anchor include a noticeably higher price – about 650 rubles only for a cartridge with an adhesive mixture of 300 milliliters. 10 ampoules (recall – one for one hole) can cost 1250 rubles. In addition, the fasteners themselves are required..
Note that the chemical composition for fastening is not stored for a long time, you should pay attention to the expiration dates when buying it. And after opening the cartridge, the shelf life is immediately significantly reduced..
Popular brands include Fischer (Germany), Hilti (Liechtenstein), Mungo (Switzerland).