Design of flat slab for punching - European and North American practices

Abstract

Up to this day, in different part of the world, many cases of collapses were established due to punching shear. This mechanism that causes a failure is considered as the main problem of a flat slab. So, the bachelor thesis will introduce the punching shear of a flat slab, possible retrofitting systems, and their appropriate design according to the European EN 1992 1-1 and the North American ACI-318. Additonally, many factors that cause the deterioration of a slab will be discussed. The main task of interest and case study will be the real failure of Piper’s Row Car Park in Wolverhampton. It will be designed according to those provisions and the following part of the thesis will be dealt with analyzing the possible deterioration that will lead to the failure. A major part of the thesis will introduce and describe the reduction factors of mechanical properties of the structure based on the design punching shear equations according to those two codes by modification. The degradation of the slab will be shown by so-called reduction parameter and variables for that will be the effective depth, amount of shear, and the flexural reinforcement ratio. The final part of the thesis will indicate a possible extend of the European EN 1992 1-1 and the North American ACI-318 codes in regards with deterioration processes of both effective depth and corrosion of reinforcement, at the end will be the comparison and discussion of which of those provisions will show more conservative results and which one less. Thesis will include author’s reasonings of obtained results and their applicability.

Up to this day, in different part of the world, many cases of collapses were established due to punching shear. This mechanism that causes a failure is considered as the main problem of a flat slab. So, the bachelor thesis will introduce the punching shear of a flat slab, possible retrofitting systems, and their appropriate design according to the European EN 1992 1-1 and the North American ACI-318. Additonally, many factors that cause the deterioration of a slab will be discussed. The main task of interest and case study will be the real failure of Piper’s Row Car Park in Wolverhampton. It will be designed according to those provisions and the following part of the thesis will be dealt with analyzing the possible deterioration that will lead to the failure. A major part of the thesis will introduce and describe the reduction factors of mechanical properties of the structure based on the design punching shear equations according to those two codes by modification. The degradation of the slab will be shown by so-called reduction parameter and variables for that will be the effective depth, amount of shear, and the flexural reinforcement ratio. The final part of the thesis will indicate a possible extend of the European EN 1992 1-1 and the North American ACI-318 codes in regards with deterioration processes of both effective depth and corrosion of reinforcement, at the end will be the comparison and discussion of which of those provisions will show more conservative results and which one less. Thesis will include author’s reasonings of obtained results and their applicability.