1977 Volume 10 Pages 47-54
This paper is a report on the results of studies about post-tensioned unbonded prestressed concrete beams. Test results of 12 rectangular beams were gained, involving (1) theree post-tensioned bonded prestressed concrete beams without bonded unprestressed reinforcement, (2) theree post-tensioned unbonded prestressed concrete beams without bonded unprestressed reinforcement, (3) three post-tensioned bonded prestressed concrete beams with bonded unprestressed reiforcement, (4) three post-tensioned unbonded concrete beams with bonded unprestressed reinforcement. The primary variables were the presence or absence of bond: the effective prestress force of tendon: the amount of bonded unprestressed reinforcement. On the basis of test results, we considered flexural behavior and a method of calculation of flexural strength of unbonded prestressed concrete rectangular beams.