Title:
Verification of Punching Shear Provisions for Reinforced Concrete Flat Slabs
Author(s):
Noel J. Gardner
Publication:
Structural Journal
Volume:
108
Issue:
5
Appears on pages(s):
572-580
Keywords:
code provisions; flat slabs; punching shear; structural design
DOI:
10.14359/51683214
Date:
9/1/2011
Abstract:
This study compares the punching shear provisions of ACI 318-08 (ACI Committee 318 2008), BS 8110-97 (1997), DIN 1045-1 (2001), CEB-FIP MC90 (1993), EN 1992-1-1 (2004), and Gardner (1996) for interior column slab connections with and without moment transfer and edge and corner column slab connections with published experimental data. The code equations cannot be directly compared due to the different philosophies used in their derivations. Comparisons with experimental data indicate that the equations of ACI 318-08 and Gardner (1996) for concentric punching shear used the 5% probability value to determine the equation coefficients, whereas CEB-FIP MC90, EN 1992-1-1, and DIN 1045-1 used the mean value coefficients. ACI 318-08 and Gardner (1996) have satisfactory equation safety indexes (3.40 and 3.14, respectively), whereas DIN 1045-1 and EN 1992-1-1 are marginally less satisfactory at 2.8 and 3.0, respectively. Expected equation coefficients derived using mean measured concrete strength—not code equation coefficients—should be used to compare a prediction equation to a single result or group of experimental results. The ACI 318-08 elastic eccentric shear interaction method and the CEB-FIP MC90/EN 1992-1-1 plastic eccentric shear interaction method are equally effective for interior column slab connections with moment transfer and edge and corner column slab connections with the eccentricity towards the slab. The BS 8110-97 equation is effective for interior column slab connections with moment transfer.