Abstract:

Six full-scale PC(Prestressed Concrete)fiat plate-T-shaped column connections,of which five are post-tensioned with unbonded tendons and one is a parallel specimen constructed with normal bo nded rejnforcjng bars,are experimentally tested to reveal their punching shear performances when being subjected to gravitv loads.The failure modes of the connections are then investigated.The results show that a combined flexural and punching shear failure occurs for each connection ,and that,when the applied load approaches the failuI℃ load,the tendon stre~ greatly increases but does not achieve the ultimate strength. Moreover,the pr -compression stresses in slabs can improve the ultimate strength and stifness of the connection, with the ductility being fairlv kept.Th e profile of the critical section and the location of the flexural failure aIle also presented based on the experimental results,and,finally,the experimental ultimate strengths of the six connections aIle comDaIled with the results obtained according to the provisions in the ACI and the Chinese codes

Key words: unbounded post-tensioned prestressed concrete, fiat plate, T-shaped column, connection, punc-hing shear , failure mode