Torsional behaviour of prestressed concrete girder with precast box segments

In this paper, various splicing methods for prestressed precast concrete members are suggested and examined through tests. Five specimens were manufactured including a monolithic girder in order to evaluate their torsional capacity. The spliced specimens consisted of two hollow segments into which steel box tubes were inserted. All specimens were prestressed and spliced using splice sleeves. Shear keys were applied to three of them. Crack patterns, failure modes, load-strain relations and moment-rotational angle relations were compared in order to evaluate torsional performance of the specimens. When the maximum torsional moment was applied, no separation of the connection occurred in the specimen in which steel tubes of both segments were welded, whereas separation occurred in the specimens in which one end of the steel tube was inserted into the other larger steel tube. The specimen SGW to which welding the steel tubes and prestressing were applied had approximately 77% torsional moment capacity compared with the monolithic specimens and around five times the angle of twist compared with the other spliced specimens.