Post Tensioning Elongation
Post Tensioning Elongation
(OP)
We have been asked to provide PT elongation calcs. I cant seem to find a standard equation to use, is that something the mfg of the PT cable would provide for us?
When was the last time you drove down the highway without seeing a commercial truck hauling goods?
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Post Tensioning Elongation
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RE: Post Tensioning Elongation
BA
RE: Post Tensioning Elongation
RE: Post Tensioning Elongation
0.076" per foot.
RE: Post Tensioning Elongation
RE: Post Tensioning Elongation
RE: Post Tensioning Elongation
BA
RE: Post Tensioning Elongation
RE: Post Tensioning Elongation
RE: Post Tensioning Elongation
Any decent text book on PT and many design codes have formulae for calculating the Prestressing force in tendons, allowing for friction and elastic shortening.
Then use PL/EA but remember P varies along the tendon, it is not the jacking force.
Do not believe ext/length numbers. They vary depending on the situation.
I agree that expected extensions should never be made known to the stressers, but that is not the PTI practice who recommend that they be on the drawings. I have seen too many cases of the expected results being achieved (according to the records) to recommend that practice. Their arguement tends to be that knowing the extension will avoid overstressing. Watching the gauge will avoid overstressing! Stressing to an extension can often cause overstressing if there is extra friction or a blockage in the tendon.