ACI 318 Load combinationS for POST-TENSIONING: Where?
ACI 318 Load combinationS for POST-TENSIONING: Where?
(OP)
I am using ADAPT and SAFE PT to design post-tensioning and found discrepancies for the load combinations for serviceability.
ADAPT:
1.0D+0.3L+1.0PT
SAFE:
1.0D+0.5L+1.0PT
1.0D+1.0L+1.0PT
Both programs refer the comb. to ACI chapter 18. However, after checking ACI 02, 05, 08, I must say I could NOT find any specific clauses in ACI which clearly list the load combinations, either service or strength states.
Does anybody know where in ACI 318 we can find the load combinations for PT?
ADAPT:
1.0D+0.3L+1.0PT
SAFE:
1.0D+0.5L+1.0PT
1.0D+1.0L+1.0PT
Both programs refer the comb. to ACI chapter 18. However, after checking ACI 02, 05, 08, I must say I could NOT find any specific clauses in ACI which clearly list the load combinations, either service or strength states.
Does anybody know where in ACI 318 we can find the load combinations for PT?






RE: ACI 318 Load combinationS for POST-TENSIONING: Where?
RE: ACI 318 Load combinationS for POST-TENSIONING: Where?
the 0.3 factor in ADAPT and the 0.5 or 1.0 factor in SAFE are the program selection. In other words, they are the corresponding engineers' selection, NOT something ACI 318 explicitly specified.
That being said, SAFE might yield more conservative design than ADAPT.
Am I right???
RE: ACI 318 Load combinationS for POST-TENSIONING: Where?
RE: ACI 318 Load combinationS for POST-TENSIONING: Where?
My understanding for ACI318 design for service crack control design is it is based on a short term (Frequent)loading of
1.0 SW + 1.0 SDL + 1.0 LL + PT effects
Deflection then uses short term and permanent loading cases if it is done properly (not so in Adapt) with the permanent loading used to determine creep and shrinkage effects and the short term loading for the final total deflection.
The Eurocode combinations do NOT apply to ACI code and cannot be used for it!