Partial shear diagram of slim‐floor beams

Abstract

AbstractSlim‐floor beams which have the steel sections fully or partially integrated into the concrete slab lead to a significant reduction of the construction height. Due to its flat lower surface, it provides favourable solution for technical installation. According to EN1994‐1‐1, for composite beams plastic moment resistance is assumed. In the case of slim‐floor sections, due to the reduced construction height by the integration of the steel beam in the concrete and its extended bottom flange, a large compression zone height may be expected, thus concrete failure in the compression zone may happen before reaching the plastic moment resistance Mpl,Rd. Here, strain limit resistance becomes decisive. For design with partial shear connection, EN1994‐1‐1 provides the partial shear diagram based on the plastic bending resistance Mpl,Rd which is not always suitable for slim‐floor beams. Based on strain limited method, the more suitable partial shear diagram of different slim‐floor beams can be developed. From parametric studies of different types of slim‐floor beams, the impacts of critical parameters on the design are highlighted, and the limitations of the current plastic resistance based partial shear diagram are suggested. A simplified calculation method for situation beyond the limitation are also proposed to guarantee an economical design of those beams.