Semi-rigid composite moment connections - experimental evaluation

摘要

Steel beam-concrete slab composite floor systems are widely used in Australia due to inherent advantages such as construction speed, economy and better quality control. However, the current Australian Code AS 2327, (1996) for composite construction covers only the design of simply supported composite beams. Even though the British Code BS 5950, (1990) and Eurocode 4 (1985) provide design guidelines for continuous composite beams, the beams need to have continuity over the supports or full moment connectivity if the beams are discontinued at the supports. This paper investigates the effectiveness in achieving continuity of simply supported composite beams, with standard cleat plate end connections, by providing additional top reinforcement in the slab over the support. The test results show, with the addition of a few additional reinforcing bars over the simply supported ends, semi-rigid connectivity can be achieved and the beams tend to behave as a partially continuous member. This in effect improves the load carrying capacity and the stiffness of the floor system with minimum cost. This also enhances the performance of the floor under fire as the proposed method providing adequate end anchorage for the beams to act in catenary under large plastic deformations.