What does it mean and how do you design for it?
Redundant fastenings are for non-structural systems and can carry loads in event of failure!
Originally, the requirements for redundant fastening were found in ETAG001 Part Six but this has been superseded by Eurocode.
Not much has changed as shown in the snippets below:
What does this mean for you as a designer?
- For non-structural redundant fastening system, the failure of individual anchors is compensated by adjacent fastenings.
- The design takes an extremely conservative approach, which explains the low maximum design load per fixing point
What products and under what circumstances can be used for redundant fastening?
- A Product’s Technical Data sheet indicates if a product can be used for redundant fastening!
It is important to note that ETA documents do not mention redundant fastening and that requirements for redundant fastenings are made available in a product's technical data sheets
- The type of concrete and design load plays an important role in determining applicability!
There is a specific ratio to be adhered to for prestressed hollow core slabs. Maximum design loads are capped at 2kN and 3kN for 3 and 4 minimum number of fixing points respectively.
To find out more, please get in touch with us or with your Hilti engineer to find out more!