It's known that for the pre-tensioned members, the tendons are stressed first and soon the concrete is placed which leads to a (what I call) perfect bonding between the tendon and the surrounding concrete. This achieved bonding is the main key to transfer the stresses. In case of post-tensioning, the tendon is placed through ducts and stressed later after the concrete is poured, which means there's no bond (at least not a perfect one) between the tendon and concrete. So how would the pre-stress transmission work here? I understand that for bonded tendons the grout will help in building that friction between the two surfaces and hence transferring the stresses, but what about the un-bonded ones? Why would we use the un-bonded system?
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Muhannad Husain S.M.ASCE
Researcher
Hohai University
Nanjing
+86 183 5193 3411
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