Comparison of Punching Shear Design Provisions for Flat Slabs

Sammanfattning: Abstract A new generation of EN 1992-1-1 (2004) also known as Eurocode 2 is under development and currently there is a set of proposed provisions regarding section 6.4 about punching shear, PT1prEN 1992-1-1(2017). It was of interest to compare the proposal with the current punching shear design provisions. The aim of this master thesis was to compare the punching shear resistance obtained in accordance with both design codes. Furthermore the eect of some parameters on the resistance was to be compared. It was also of interest to evaluate the userfriendliness of the proposal. In order to meet the aim, a case study of a real 　at slab with drop panels was performed together with a parametric study of a pure ctive 　at slab. The parametric study was performed for inner, edge and corner columns in the cases prestressed, without and with shear reinforcement. It was concluded that the distance av from the column axis to the contra 　exural location has a big in　uence on the punching shear resistance. The factor ddg considering concrete type and aggregate properties also has a big impact on the resistance. The simplied estimation of av according to 6.4.3(2) in PT1prEN 1992-1-1 (2017) may be inaccurate in some cases. The length b0 of the control perimeter has a larger eect on the resistance in EN 1992-1-1 (2004) than in PT1prEN 1992-1-1 (2017). In PT1prEN 1992-1-1 (2017), studs located outside the second row has no impact on the resistance. The tensioning force in a prestressed 　at slab has a larger in　uence on the resistance in PT1prEN 1992-1-1 (2017) than in EN 1992-1-1 (2004). Furthermore, the reinforcement ratio is increased by the tendons, and thus aect the resistance in PT1prEN 1992-1-1 (2017). Clearer provisions for the denition of the support strip bs for corners and ends of walls are needed in PT1prEN 1992-1-1 (2017). It may be questionable if the reduction of the perimeter for a large supported area in accordance with 6.4.2(4) in PT1prEN 1992-1-1 (2017) underestimates the resistance v in some cases. Considering the work-load with PT1prEN 1992-1-1 (2017), more parameters are included. However, they may not require that much eort to obtain. Keywords: Punching shear, resistance, concrete, 　at slab, design provisions, Eurocode 2, case study, parametric study, shear reinforcement, prestressed vi