There are many different types of anchors for metal structures to keep the structure firmly secured to the ground.
Novelty Steel supplies a detailed Anchor Bolt Plan for steel constructions. These plans show the building dimensions, the precise locations for anchor bolt placement, and the total number of foundation anchor bolts required in the structure.
Depending on when the anchors are installed and the foundation types, anchors used by Novelty Steel are classified into two categories;
2. Cast-in Anchors
These are the type of anchor bolts that are installed in place before pouring the concrete and are efficient in handling forces of high magnitude. Bolts are firmly held in place while the concrete is poured to maintain proper alignment and position.
The size and location of the anchors can be determined within the steel detailing works.
In the below figure, you can see some examples of cast-in anchors.
Figure 1 Cast-in Anchors
3. Chemical Anchors
Adhesive anchors are anchor bolts that are placed in a pre-drilled hole, which contains an adhesive that dries and bonds to the anchor rod thread as well as the concrete. Adhesive anchors, also known as epoxy anchors or chemical anchors, are capable of reaching high bond-stress values in relatively fast cure times. Adhesive anchors are fully threaded rods that can be supplied in many different grades and finishes and can be cut to any length required for a given application.
Good installation is critical to the performance of anchors. Here is the 5-step for the installation.
- DRILLING: Drill correct hole size and depth on concrete/brick/stone/masonry.
- HOLE CLEANING: Blow out dust and clean the hole with brush, then blow out remaining dust.
- INJECTING: Inject mixed adhesive from the bottom of the hole.
- INSERTING: Insert and rotate stud/bolt/anchor/rebar/threaded rods into the hole.
- HARDENING AND CURING: Time table refer to TDS. Don’t touch until full curing.
Figure 2 Anchoring Steps
- All structural columns on a building must be anchored by at least four anchor bolts
- The placement of all actor bolts on the structure must adhere to the approved Engineered Foundation Plan
- All anchor rods shall be placed with their longitudinal axis at a 90-degree angle to the surface of the foundation
- A template (preferably steel) must be used to insure exact placement of anchor bolts in concrete.
Anchor bolts are not just the connection elements between the steel and concrete surfaces but they are one of the most important element in steel structures. Anchor bolts are responsible for the transfer of loads between the steel and concrete member. The proper installation of the anchor is as important as the correct design and fabrication.