Structural Concrete, Vol. 6, no. 1, March 2005
Punching resistances of unbonded post-tensioned slabs by decompression methods
R. J. Carvalho Silva, University of Brasilia, Brazil
P. E. Regan, University of Westminster, UK
G. S. S. A. Melo, University of Brasilia, Brazil
This paper presents the direct decompression method for calculating the punching strengths of post-tensioned slabs. It is a method already used for determining the shear strengths of beams. In many respects it is similar to the Fédération Internationale de la Précontrainte (FIP) treatment of punching in post-tensioned slabs, but it is simpler to use. The predictions of two variants of the direct decompression approach, and of the FIP method, are compared with the results of tests of slabs with various arrangements and profiles of tendons. It is shown that the direct method reduces the scatter of ratios of experimental and calculated strengths although all three approaches provide reasonable results.