In 2011, seismic upgrades and structural improvements were taking place all over the St. Louis area. Passersby seemingly couldn’t travel more than a mile without driving passed a bridge being repaired and upgraded with seismic strengthening. The Edward Jones South Campus in St. Louis joined the movement and approved a project to strengthen and upgrade the building’s column to beam at each floor of the 9-story office building. The Concrete Restoration Branch of Western Specialty Contractors was selected to complete the project.
The project included seismic strengthening to approximately 360 concrete column to concrete beam connections at the West Tower’s exterior columns. Access to the strengthening locations proved no easy task, as it required removal of a grid ceiling, removal and relocation of electrical conduits and equipment wiring, and removal of metal stud framing with drywall sheathing in the plenum space above the ceiling grid.
Western’s craftsmen were then able to drill holes into the concrete column, install a saturated carbon fiber reinforcing fabric manufactured by Sika at the underside of the beam, and install a steel angle secured to the column faces with high-strength stainless steel dowels set in an epoxy adhesive. Each column had a different seismic design, thus the number of holes to drill and the number of layers of carbon fiber varied with each column. Overall, our craftsmen drilled over 1,400 holes, in some occasions completely through a 24” thick column, and installed over 7,500 square feet of carbon fiber. The work was completed during off-business hours to minimize the impact on office personnel. Therefore, daily cleanup and demobilization were a must with a high expectation for cleanliness. All interior finishes, utilities, and wiring had to be reinstalled upon completion of the work.