Evaluating slab thickness in reinforced concrete flat-plate construction by Dimitri Papagiannakis, PE
Reinforced concrete flat-plate construction is popular among mid- and high-rise residential construction projects. It provides a great deal of flexibility in the placement of the structure’s vertical load-carrying elements (i.e. columns and walls) without sacrificing the efficiency of the floor framing—as could potentially be the case with steel or masonry.
In the project’s early stages, structural engineers are often asked by architects …
The University of Missouri, located in Kansas City, boasts the country’s first terra cotta-clad insulated composite precast concrete panels assembly.
Before this installation, terra cotta had been clad into non-insulated panels in a few projects. At the Henry W. Bloch Executive Hall for Entrepreneurship and Innovation, however, terra cotta tile was clad onto 1783 m2 (19,200 sf) of 3.6-m (12-ft) wide insulated composite precast concrete sandwich panels.
Thin, short strands of steel are being increasingly specified as reinforcement in ground-supported slabs and in composite steel deck-slabs. Structural engineers are still figuring out how best to design with these components, but specifiers need to think about how to define this material in the contract documents. Dosage is critical, for one thing, but not all fibers are alike. Without specifying other key details, one can end up with concrete that contains the specified mass of fibers, but does not fulfill the designer’s intentions.
To some, it may seem impossible to meet the flatness required by the Americans with Disabilities Act’s (ADA’s) 2.1 percent maximum slope for random traffic floors, landings, walkways, sidewalks, curb ramps, entrances, exit ways, ramps, and intersections at walkways. However, predictable concrete flatness techniques are achievable, provided the design/construction team follows certain practices and engages in specific strategies.