Parametric study of the load-bearing mechanisms in RC beam-grids to resist progressive collapse

Recently, several structural failures demonstrated the disastrous consequences of progressive collapse andraised the awareness of the engineering community. However the low probability of progressive collapsemakes it uneconomical to design every building against progressive collapse using conventional designmethods. Furthermore in most cases the initiating events of progressive collapses are unknown during thedesign. As such, consideration of secondary load-carrying mechanisms can be an effective alternative. Thesemechanisms include compressive arch action (CAA) and tensile catenary action (TCA) in reinforced concrete(RC) beams. Several researchers have investigated the effects of CAA and TCA experimentally and numericallyin individual RC beams. However to date limited studies have been carried out to study these mechanisms inRC beam-grids. Hence in this contribution a validated numerical model is developed to study and quantify theindividual contributions and development of the different mechanisms in RC beam-grids. Parametric studiesare performed in relation to the influence of the aspect ratio of the grid, reinforcement ratio and ultimatereinforcement strain.Recently, several structural failures demonstrated the disastrous consequences of progressive collapse andraised the awareness of the engineering community. However the low probability of progressive collapsemakes it uneconomical to design every building against progressive collapse using conventional designmethods. Furthermore in most cases the initiating events of progressive collapses are unknown during thedesign. As such, consideration of secondary load-carrying mechanisms can be an effective alternative. Thesemechanisms include compressive arch action (CAA) and tensile catenary action (TCA) in reinforced concrete(RC) beams. Several researchers have investigated the effects of CAA and TCA experimentally and numericallyin individual RC beams. However to date limited studies have been carried out to study these mechanisms inRC beam-grids. Hence in this contribution a validated numerical model is developed to study and quantify theindividual contributions and development of the different mechanisms in RC beam-grids. Parametric studiesare performed in relation to the influence of the aspect ratio of the grid, reinforcement ratio and ultimatereinforcement strain.C