Concrete, steel testing helps bring Seattle Aquarium to life

Client

Seattle Aquarium Ocean Pavilion (SAOP)

Location

Seattle, WA

Challenge

The centerpiece of the Seattle Aquarium Ocean Pavilion (SAOP), which opened in August 2024, is a custom-built 325,000-gallon tank. Aquariums that large exert massive amounts of pressure on the exterior walls. Our Special Inspectors were trusted with the responsibility of verifying all reinforcing steel placed for the walls and slabs, as well as structural steel inspections on other portions of the $160-million aquarium.

The tank presented the most unique challenge. The congestion created by nearly 3 million pounds of steel rebar in the walls – it takes A LOT of strength to hold back that much water – made standard concrete an unsuitable choice for the exterior tank walls. The aggregate in the concrete would separate before properly settling. A high-strength, 10,000-psi grout was chosen instead. The safety of both visitors and sea creatures alike depended on accurate sampling, curing, and testing of the grout.

Solution

Performing Special Inspections was complicated on multiple fronts. The size and shape of the tank forced us to inspect the rebar and grout in sections, as it was being completed. By being on-site every day, we completed inspections in a timely manner so the contractor could proceed with construction. Our inspectors completed nearly 650 material tests and countless inspections as the tank was under construction. We performed field testing and inspection, welding inspections onsite and at fabrication shops, and laboratory material testing which included concrete, shotcrete, and grout with the collaboration the contractor and subcontractors.

Results

Our team’s testing data confirmed that the materials used to construct the tank and other aspects of the aquarium could handle the pressures and strains unique to the structure’s purpose. 

Seattle is a city filled with iconic landmarks, and the aquarium adds to the list. It spans 50,000 square feet, targets LEED New Construction Gold certification, welcomes 1.2 million guests annually, and operates 100% fossil fuel-free.