Anchor Bolts - Selection and Usage
Anchor bolts are the term used for the items that are used to join objects to concrete. Anchor bolts are available in various forms and shapes, generally having designs or emblems printed on them that are trademark of a company that manufactures them. Regardless of their shapes and look, they all have similar usage. Anchor bolts generally are have a threaded end to which one can add a nut or a washer. Anchor bolts are utilized for various things like constructing buildings, attaching wooden frames to the walls and paneling of walls, transferring load from a wall to the roof top, anchoring of shear walls, holding devices in line and holding beams in position for large structures or walls (e.g., skyscrapers and dams). Anchor bolts are usually taken for granted by an average human but they are important items that individuals require for many structures.
The “cast-in-place” anchor bolt is the strongest, simplest and the most common type of all bolts. This bolt comes with a hexagonal head which is placed into the wet concrete before setting it. These anchors are utilized for heavy machines on the concrete ground as they are tough to cast with. Bent hood design with a sharp hook at the tip is another design of anchor screw which is not as common and simple as the cast-in-place anchor bolts. However, both of these types of anchor bolts have different uses. At present, there are many devices that are used to help in holding and placing of the anchor bolts in concrete settings. These devices are made up of composite plastic. Bolt snap is a new device which is adaptable to various sizes of anchor bolts diameters.
Epoxy and mechanical anchor bolts are used after the concrete has been fixed. They are the strongest but very tricky to install. Epoxy anchor bolts are among the most powerful bolts but are difficult to install because they have to be put in the very precise position and into a clean hole not to mention the time in which it sets in the concrete has to be monitored vigilantly. Ignorance while installing epoxy anchor bolts may lead to disasters. The mechanical bolts come with a wedge arrangement at the end. There may be a variation in its theme depending upon the type of load it lifts and the kind of concrete it is installed into. In case of the failure of mechanical wedge, the wedge of the concrete is pulled out, therefore one must not place them too closely while installing them. Rock bolt is a specialized form of anchor bolts that are mainly used in excavations.
Next is the wedge anchor that comes in a fully threaded body. The diameter of the unthreaded part of wedge anchor is less than the threaded part. The long threaded portion facilitates leveling and shimming of the item being secured. But there is a disadvantage to this feature. When the anchor bolt is put in a hole of depth less than the minimum embedment specified, it can be torque causing the anchoring power to be diminished and creating an unsafe anchor. Be sure to always fully seat your anchor bolt so the entire thread is no longer visible.