Punching shear failure is the main problem with flat slabs. Extensive research has been undertaken in the last few decades to understand the behaviour and to develop systems to minimise the effects. The use of shearhead has proven to be an effective system to reduce punching shear phenomenon in flat slab construction. The development of pultruded fibre reinforced polymer (FRP) as columns in flat slab construction is limited in scope. This study addressed some of the intricate issues around developing shearheads and the interface with FRP column, and the effect of load-carrying capacity and mode of failure. Five specimens were fabricated to investigate load capacity and modes of failure of the isolated T joints. The specimens vary in terms of the configuration – simple joints, joints with ‘bridging’ plates; joints with ‘cap’ plates and joints with both ‘bridging’ and ‘cap’ plates. The study adopted 152 × 76 × 6.4 mm I section. The shearhead adopted was 50 × 50 × 6 mm square hollow section, grade S355, connected to the FRP via 6 mm thick grade S275 steel plates. The connecting bolts were grade 8.8 M8. The joints were tested in a simply supported arrangement. Load-displacement and load-strain responses are plotted. Failure of specimen was predominantly due to excessive deformation of the joint assembly, failure of fillet welds, buckling of the FRP stub column and other failure mechanisms associated with FRP-steel bolts and plate assembly. The study shows promise of using FRP to construct flat slab by connected shearheads to the FRP column. To prove the concept, an FRP/flat slab specimen was constructed and tested under static vertical loads, the outcome of which is to be presented in a separate paper.
|Number of pages||15|
|Publication status||Unpublished - 4 Oct 2019|