The inventors and original supplier of a popular shear-stud reinforcement for two-way flat slabs in concrete frames are up in arms over charges, based on recent research, that the American Concrete Institute's model code governing use of the studs is flawed. The researchers claim that, consequently, there is potential for premature failure due to punching shear at slab-column connections, especially under earthquake loads.A. Ghali, professor emeritus of civil engineering, University of Calgary, Alberta, Canada, and the lead researcher for original studies on shear studs dating back to the 1970s, disagrees. Extensive testing shows that code-specified "equations and detailing for the
The market is generally healthy and steadily growing, and margins are up for large specialty contractors. Further, advances in design tools and owner demand for collaboration are giving subcontractors a seat at the table early on in projects.