AWARD OF EXCELLENCE: Strengthening Category

Column and Beam Enlargements Using Self-Consolidating Concrete at a
U.S. Ski Resort

Submitted by Structural Preservation Systems, LLC

Constructed in 2006, the condominium/hotel facility at a major ski resort offers high-quality lodging in studio to three-bedroom condominium units. The structure features an underground parking garage, which is an important amenity to patrons. Upon completion of the construction and loading of the building, many cracks appeared on the underside of the garden level slab, which was also the ceiling of the upper level of the parking garage. After hiring an independent consultant to perform a structural review of the building, the owner learned that the building had been underdesigned and there were construction deficiencies. In fact, the building was not in code compliance and structural remediation was needed. To ensure the safety of patrons, the owner had to shore the ceiling of the parking garage, which eliminated 75% of the parking spaces.

Upon inspecting the repair design drawings, the repair contractor developed an innovative repair strategy using self-consolidating concrete (SCC) for the 59 beams and
16 columns that needed to be constructed underneath the garden level slab. The forms for the beams were completely enclosed, so placing conventional concrete would not have been possible. The flowability of SCC allowed the concrete to flow properly around the tight reinforcing steel. In addition, pumping SCC under pressure achieved the bond between the existing and new concrete.

There are several items that make this project unique. The first was the use of undercut anchors to fasten the reinforcing bar cage to the existing slab, which is not standard practice in concrete enlargement applications. Also, the use of SCC in a very challenging environment was a key feature of the project. Finally, a large amount of upfront testing allowed the team to assess how the materials would perform in real-life conditions, which set the project up for success from the onset.

Owner
(Owner information kept confidential by request)

Project Engineer/
Designer
Simpson, Gumpertz &
Heger, Inc.
Rockville, Maryland

Repair Contractor
Structural Preservation Systems, LLC
Elkridge, Maryland

Material Suppliers/
Manufacturers
The Euclid Chemical Company
Cleveland, Ohio

Central Supply Company
Elkins, West Virginia