Strengthening and Restoration of Casino
Resorts Casino in Atlantic City is open for business 24-hours-a-day. Originally constructed in the 1920s, the casino was a twin tower structure. The owner, however, recently demolished one of the original towers and constructed a new, state-of-the-art hotel tower in its place. Of utmost importance to the Owner – connecting the two buildings to give guests full access to the revenue generating casino.
Creating this connection was the final phase of the project, but it presented unique challenges. Because the two towers were at different elevations, it was necessary to build the concourse on an incline. Building on the incline, however, meant that the existing intermediate slab had to be removed in order for the concourse to pass through the lower elevation to the higher one. The removal would double the unsupported length and could cause the columns supporting the original building loads to buckle. The columns, as well as two other areas, a steam tunnel and the Grease Recovery Unit Room (GRU), also had to be repaired and/or strengthened before the new concourse could be completed.
Because it was critical to the Owner to complete the project on time, a timely evaluation, repair strategy and installation process was essential. It was decided to use a variety of strengthening and repair methods for the different repairs, including complex shoring systems, self-consolidating concrete and a carbon fiber reinforced polymer (CFRP) system. Most critical to execution was implementing it in a manner that would allow the casino’s very profitable operations to continue uninterrupted.
Traditional methods for strengthening columns involve steel and concrete in the form of an enlarged external jacket around the column. This method must be performed monolithically with the column to provide resistance to higher buckling forces and in this case would have increased the overall column size – making the egress width of the new corridor below code. Instead, the team chose to use CFRP – bonding it to the columns with epoxy adhesive in both horizontal hoop and continuous vertical sheets. While adding less than one inch to the column size, they effectively upgrade the column for both buckling and current load carrying capacity codes.
Within the steam tunnel, it was discovered that the original structural beams that were supporting the slab had never been maintained. They had severely deteriorated to the point that they would not be able to carry the new loads. In many areas, the steel rebar was fully exposed or completely deteriorated. Not only would these involved members require repair, they would also have to be strengthened to meet current design codes. The strengthening plan employed an enlargement technique bonding a reinforced concrete jacket to each existing beam.
Repairing the below sea-level room that contained the GRU proved to be a challenge. The concrete ceiling and three very large columns in the room had deteriorated to a point of structural concern. Once the original ceiling structure was removed, formwork was placed and a new two-way slab and beam system was cast with new hangers and supports for the piping and the equipment. Reinforced enlarged sections were added to repair and strengthen the columns.
These innovative repair and strengthening strategies allowed the casino to remain open during repairs and the project to be completed ahead of schedule.