dcarr82775
Structural
I had previously only used the old 1992 AASHTO. I understood the fatigue rules for concrete in that edition. Fatigue was checked at service level stresses and that makes sense to me.
We recently got a copy of AASHTO 2010. Our office does not design bridges, but occasionally come across a project where AASHTO is more appropriate in our minds than ACI-318.
The 2010 version doesn't explicitly state the concrete fatigue checks are for service level loads but I assume they are. There is a 'Fatigue I' load combination that applies a factor of 1.5 to the live loads.
My question is are the fatigue stresses checked at service load levels with the exception that you apply a 1.5 factor to the live loads (i.e. 1.0 factor on all sustained loads, 1.5 on the live/impact loads)?
Thanks
We recently got a copy of AASHTO 2010. Our office does not design bridges, but occasionally come across a project where AASHTO is more appropriate in our minds than ACI-318.
The 2010 version doesn't explicitly state the concrete fatigue checks are for service level loads but I assume they are. There is a 'Fatigue I' load combination that applies a factor of 1.5 to the live loads.
My question is are the fatigue stresses checked at service load levels with the exception that you apply a 1.5 factor to the live loads (i.e. 1.0 factor on all sustained loads, 1.5 on the live/impact loads)?
Thanks