California Academy of Sciences / San Francisco
After being damaged by an earthquake in 1989, the California Academy of Sciences needed a new home. Sustainability and conservation have been part of the Academy's history for more than 150 years, so the new building had to exemplify environmentally superior construction.
The new LEED Platinum facility integrates architecture and landscape, and helps set a new standard for energy efficiency and environmentally responsible systems in a public building. Concrete provided a solution for many critical applications in the Academy's unique design.
Compactor shelves, designed to hold collections of various research materials, ride on rails for ease of accessibility and required deflection criteria only achievable with reinforced concrete. The aquarium tanks designed with complex geometries could only be cast in concrete.
Concrete also played an integral part of the building's mechanical system and served as a thermal massing element. As one of the more abundant construction materials, it was important to choose mixes that were environmentally friendly, performed well, and durable.
All concrete mixes needed to use sustainable materials and meet an ultra-low shrinkage requirement for the aquarium tanks. Cast architectural concrete—the primary finish of the interior hallway walls—needed to deliver a perfect as-cast architectural finish. Central Concrete Supply, a U.S. Concrete division, provided 35,000 yards of concrete, utilizing environmentally friendly technology (EF Technology).
The concrete mixes consisted of 50% portland cement and 50% supplementary cementitious materials, such as fly ash and slag-reclaimed byproducts. By using EF Technology mixes, the producer prevented 9.2 million pounds of CO2 emissions from entering the environment. Using fly ash and slag, as well as regionally extracted supplies of aggregates in the concrete greatly contributed to earning the highest LEED rating.