DESIGN PRECAST LIFTING USING PRESTRESSED STRANDS OR REINFORCEMENT BARS


   


Design Code,      

Weight of precast element, wtprecast = tons (metric)    

Surface area of precast element, Aprecast = m2 (for adhesion force calc during demoulding, if no adhesion put 0 )    
Design Criteria
Lifting mechanism design for ;
Demoulding Only           Installation Only           Both    
Minimum Global FOS,     fosdemoulding   N/mm2        fosinstallation   N/mm2    
Concrete CUBE strength,    
fcu_demoulding   N/mm2        fcu_installation   N/mm2 , cube strength    
Panel Configuration During lifting,    
at casting yard =          at site (installation) =         
(Note : All 3D casting will assume poor bonding condition as the strands are placed at top of cast)
Dynamic Factor for crane lifting:,    
at casting yard =      at site =     
By lifting elements with a chain, there is a load increase resulting from the angle of inclination.
Angle of lifting sling to the vertical β ,    
at casting yard =      at site =     

Adhesion to mould (oiled steel mould)      

Nos lifting_points ,    
Demoulding stage   nos     Installation stage   nos    

Balanced lifting conditions used ? , select
All balanced lifting MUST use chain blocks and pulleys to provide equal distribution of loads. The center of gravity of the the lifting hooks must also coincide with the center of gravity of the precast elements.


Lifting mechanism used (choose one)

lifting using prestressed strands  
φstrands ,   mm     strandsnos ,   mm     fpst =   N/mm2    
lifting using Propriety Lifting Anchors  

lifting using reinforcement bars  
φrebar ,   mm     rebarsnos ,   mm     fst =   N/mm2    
Angle α1   (see here for description) from plane of rebar = degrees    

h1= mm    
b1= mm    



NOTE
ALL LIFTING POINTS TO BE SYMETRICALLY ARRANGED AROUND CENTROID OF PRECAST PANEL

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