Lifting Precast Concrete Units

[desm]

I am designing some precast reinforced concrete slabs. When the slab is lifted, it can be analysed as a simply-supported beam with the UDL provided by the self-weight of the beam and the supports provided by the lifting points. I want to apply a partial factor of safety to the UDL value, for bad lifting, but can't find any guidance on this. BS 8110-1:1997 clause 2.4.4.2 says FOS should be 1.3 for concrete in flexure due to effects of exceptional loads or localised damage. Is this the FOS I should be using?

Desm

 

[DTGT2002]

I suggest you visit the PCI website and look for a PCI design manual.

Their manuals are very thorough and have plenty of deatails and expamples of all types of precast construction examples and details.

Good luck,

Daniel

 

[Scott200577]

Hi, I work as a Production Engineer in Precast - we normally calculate the loads as normal, then if you look in a product brochure by manufacturers such as Halfen-Frimeda they will list the various factors for demoulding adhesion, crane types, transport factors etc.....

Hope this helps

 

[jheidt2543]

If you are going to need embedded lifting hardware for the precast units check out Dayton-Superior Co.'s website and catalog. They manufacture a large selection of hardware for precast concrete embeddments and their technical department could also be a big help.

 

[dicksewerrat]

I'd be worried about the lifting device you use. A spreader bar or frame to reduce the bending induced intot he precast.