TY - GEN
T1 - Influence of no longer permitted stirrup types on the shear capacity – experimental investigations on prestressed continuous beam subsystems
AU - Schramm, N.
AU - Fischer, O.
N1 - Publisher Copyright:
© 2019 Taylor & Francis Group, London, UK.
PY - 2019
Y1 - 2019
N2 - Within the scope of reassessement of older existing bridges in Germany, outdated stirrup types which are no longer permitted by current design standards (for example straight-legged stirrups) can often be found. As these stirrup types can nevertheless noticeably contribute to the shear capacity, the load bearing behavior of these bridge girders has to be further analyzed. In this context, 14 experimental tests on 0.8 m and 1.1 m high, prestressed bridge girders with four different types of stirrups were carried out. In detail, beams with conventional closed stirrups, U-shaped stirrups with straight legs, insert-stirrups in the area of the intermediate support and two-part stirrups with a reduced overlap length were tested. To enable a continuous measurement of the strain along the stirrups, fibre optical sensors were used. As a result, the bond behaviour for each stirrup type could be investigated very detailed. The tests revealed that the overlap length of stirrups according to German standards can be significantly reduced and insert-stirrups in the area of the intermediate support, as well as U-shaped stirrups, do clearly contribute to the shear capacity. To enable testing of a high number of specimen with realistic cross-sectional dimensions and at reasonable effort, an innovative experimental setup was used for the tests. The basic concept of this setup, which is based on the substructure technique, is the application of the internal stress states using six individually controlled hydraulic jacks. This enables testing in real scale the behaviour of long girders on only short sections of the girders.
AB - Within the scope of reassessement of older existing bridges in Germany, outdated stirrup types which are no longer permitted by current design standards (for example straight-legged stirrups) can often be found. As these stirrup types can nevertheless noticeably contribute to the shear capacity, the load bearing behavior of these bridge girders has to be further analyzed. In this context, 14 experimental tests on 0.8 m and 1.1 m high, prestressed bridge girders with four different types of stirrups were carried out. In detail, beams with conventional closed stirrups, U-shaped stirrups with straight legs, insert-stirrups in the area of the intermediate support and two-part stirrups with a reduced overlap length were tested. To enable a continuous measurement of the strain along the stirrups, fibre optical sensors were used. As a result, the bond behaviour for each stirrup type could be investigated very detailed. The tests revealed that the overlap length of stirrups according to German standards can be significantly reduced and insert-stirrups in the area of the intermediate support, as well as U-shaped stirrups, do clearly contribute to the shear capacity. To enable testing of a high number of specimen with realistic cross-sectional dimensions and at reasonable effort, an innovative experimental setup was used for the tests. The basic concept of this setup, which is based on the substructure technique, is the application of the internal stress states using six individually controlled hydraulic jacks. This enables testing in real scale the behaviour of long girders on only short sections of the girders.
UR - http://www.scopus.com/inward/record.url?scp=85079245442&partnerID=8YFLogxK
U2 - 10.1201/9780429426506-376
DO - 10.1201/9780429426506-376
M3 - Conference contribution
AN - SCOPUS:85079245442
SN - 9781138386969
T3 - Advances in Engineering Materials, Structures and Systems: Innovations, Mechanics and Applications - Proceedings of the 7th International Conference on Structural Engineering, Mechanics and Computation, 2019
SP - 2181
EP - 2185
BT - Advances in Engineering Materials, Structures and Systems
A2 - Zingoni, Alphose
PB - CRC Press/Balkema
T2 - 7th International Conference on Structural Engineering, Mechanics and Computation, 2019
Y2 - 2 September 2019 through 4 September 2019
ER -