Behaviour of steel-to-concrete joints moment resisting joint of a composite beam to reinforced concrete wall

Aiming at the study of steel-to-concrete joints, the RFCS project entitled "New market chances for steel structures by innovative fastening solutions" ("InFaSo" [1]) was launched. Within the experimental programme of the project, composite beam to reinforced concrete wall joints were tested. In the present paper, the results of these tests are presented. Subsequently, to determine joint properties a spring mechanical model has been developed and validated against the experimental results. The studied joint configuration is illustrated in Fig. 1. Two different transfer areas may be distinguished. The upper area consists of a reinforced concrete slab where the longitudinal reinforcement is anchored in the reinforced concrete wall. The wall and the slab were concreted at different times and therefore, no shear is assumed to be transferred between these members. Any friction is neglected. Thus, only tension is transferred through this part of the joint. At the bottom area, the steel beam sits in a steel bracket welded to an anchor plate which is fastened the reinforced concrete wall. The fixation between anchor plate and wall is achieved by headed studs welded to the plate. On the outside of the steel bracket, a plate is welded creating a "nose" which avoids the slip of the beam out of the steel bracket. The end-plate of the steel beam is used for this propose. This end-plate transmits the shear load to the steel bracket. Finally, compression is transferred to the reinforced concrete wall using a contact plate between end-plate and anchor plate. The flux of loads is schematically represented in Fig. 2 for a hogging bending moment.