Knowing the correct lap and anchor lengths is very important when detailing reinforcements. Inadequate anchoring and overlays have led to many structural failures around the world. This is mainly due to the lack of attention to small things that many do not consider important facts.
BS 8110 Part 01 1997 allows us to provide our information in a very simple way, without complicating our lives. A simplified table has been provided that can be applied in most cases.
However, when we delve into specific details, it is better to proceed with the basics rather than relying on the simplified code table.
The code also provides the method to calculate the required title length. We can use either method to detail the reinforcements.
You can use the following table to determine the overlap and anchor length of reinforcing bars depending on the type of bar used and the quality of the concrete.
This table is most commonly used by details due to its simplicity. If we know the types of reinforcement used and the grade of concrete, we can determine the overlap and anchorage lengths.
For example, let's say we use Type 2 deformed bars and Grade 30 concrete.
According to the table
Compression anchor length = 32 times bar diameter
Tension anchor length = 40 times rod diameter
We can also determine overlap and anchor lengths for grade 25 to 40 concrete.
