The American Concrete Institute (ACI) has released a paper called Assessment of Punching Shear of Flat Slabs Using Ground Slag.
The paper was written by Shahab Samad, Attaullah Shah and Mukesh C. Limbachiya. It is aimed at analysing the punching shear strength of reinforced concrete (RC) flat slabs cast from blended cement having ground-granulated blast-furnace slag (GGBS) in different proportions as partial replacement of cement.
ACI says: “Four flat slabs supported on the ends were tested under column load such that one flat slab was cast from normal concrete with no GGBS and the remaining three flat slabs were cast with 30, 40, and 50% replacement of cement by GGBS.”
The test determined experimental punching shear, midspan deflections, strain in the steel bars and cracking pattern of the slabs.
According to ACI: “The results of punching shear of flat slabs from the tests were compared with the nominal punching shear capacities proposed by BS 8110, BS EN1992-1-1/EC2, and ACI 318. The provisions of these building codes for the punching shear were observed as safe and conservative for the RC flat slab made from blended cement incorporating GGBS.”
