Prestressed Concrete Design - 6 - Stresses with Strain Compatibility Approach

This is a video lecture for Prestressed Concrete Design. This video goes through using the strain compatibility approach for finding stresses in prestressed concrete members. Short-term and long-term transformed section properties, composite and non-composite transformed section properties, decompression force, and decompression moment are discussed.

[@SwallowThePlanets]

David, thank you so much for teach this to people who wants to improve in his knowledge of PT concrete, cheers from mexico! Keep share your knowledge

[@ManhLe-br7rt]

@David Garber, Dear Mr David Garber, I have a question regarding using Modular ratio of concrete for finding strain at centroid for Live load. why don't we using Ec,eff instead of Ec and using Atr,LT instead of Atr,ST. Although live load is short term load, but live load only impacted to beam in service stage, that mean is concrete has been considered shrinkage, creep,.... So using Ec,eff is more exactly. Is that right?

[@davidgarber1664]

@Manh Le - good comment/question. Ec,eff and Atr,LT should be used for any sustained loads; these take into account creep of concrete and strand relaxation. Live loads that are not sustained won't cause any creep in the concrete, which is why using Ec and Atr,ST is appropriate. The shrinkage of concrete is accounted for with the shrinkage strain in No and Mo. I hope that clarifies.