Shear keys are designed to resist the lateral movement of structures that can be caused by earthquakes and other natural events. They are often used in the construction of retaining walls, culverts, bridges and other structures in seismic regions of the country. This industrial project in Gregory, Texas required the installation of almost 150 shear keys. The forms for the shear keys, which measured 18-1/2” diameter x 6” tall were made of 1.8 pound density expanded polystyrene. The contractor wrapped the EPS forms in duct tape, then coated the duct tape with a release agent and secured them in place with wood framing.
EPS block-outs are used in all types of concrete construction in both horizontal and vertical applications creating archways, tunnel openings and manhole openings to name a few.