The bond between prestressing steel and concrete plays an important role in transferring prestress force to concrete in pretensioned prestressed concrete members. The purpose of the present paper is first to identify the bond behavior between prestressing steel and concrete…
The bond between prestressing steel and concrete plays an important role in transferring prestress force to concrete in pretensioned prestressed concrete members. The purpose of the present paper is first to identify the bond behavior between prestressing steel and concrete and then employ this bond crack model in the numerical analysis to obtain the transfer length realistically in pretensioned prestressed concrete members. For this purpose, several series of tests have been conducted in the present study. From the present tests, the bond-slip relations for pretensioned members were first obtained by measuring the strains in prestressing steel and concrete at various locations. A realistic bond-slip relation was derived from the present tests. The bond-slip model derived in the present study was then used to formulate the properties of interface element between prestressing steel and concrete. A numerical analysis incorporating smeared crack model was conducted in the present study to obtain the transfer length theoretically.The present study indicates that not only the diameter of prestressing steels and prestress intensity, but also the compressive strength and concrete cover affect greatly the transfer length in pretensioned members. The present test results indicate that the transfer length decreases with an increase of concrete cover and also decreases with an increase of concrete compressive strength. Therefore, these effects must be considered in the design code to accurately design the pretensioned concrete structures. It was shown in this study that the results of numerical analyses agree well with the test data.