Precast concrete made it possible for construction crews to restore the Alaska Capitol Building back to its 1929 original appearance on time and with no disruption to the Alaskan legislature’s active sessions.
According to numerous studies conducted in 2006 by Building Envelope Consulting Services, the effects of 80 years of long, harsh Juneau winters had finally taken its toll on the Alaska Capitol Building’s exterior architecture. Displaying signs of leakage, degradation and stress such as spalling bricks and cracked sandstone, the legislature voted to sett aside funding to fix the deteriorating exterior envelope. With enough funding collected, project bidding was sent out in 2013 and Jensen Yorba Lott architect services was awarded to find a solution for restoring the building’s finishes, renewing historic design elements and adding seismic retrofits to the entire structure. The project was completed in three phases over four years.
Wayne Jensen, principal architect, said precast concrete offered the best fit for the restoration repairs since the material met the legislature’s requirements and aided in maintaining the building’s original appearance.
“Precast concrete was used since it matched as close as possible to the color and texture of the original stone cladding,” said Wayne Jensen, principal architect. “The building’s original stone blocks were used to create the molds used for casting. The precast products offered more durability to the overall structure and were thinner and lighter than the original stone.”
The precast products manufactured by Architectural Precast Structures in British Columbia, Canada, included a second-floor water table and new cornice accent.
General contractor Dawson Construction said the precast products were used as benchmarks for the rest of the facade installation. The water table ran around the entire building and was installed first with stainless brackets and expansion bolts. The brackets used to hold the water table had to account that the existing structure moved in and out of plane as much as four inches in some areas. Instead of custom fabricating each bracket, an adjustable system was designed that could be used to keep the facade in plane while the structure varied behind it.
“The carved sandstone accents that were removed from the building had critically failed in many spots,” remarked Dawson Construction. “The precast elements we used to replace those components had integrated color and waterproofing. In addition, stainless-steel rebar was used for reinforcing and all structural supports. The capitol building is probably the most ornate precast products we have installed.”
The renovation project noted as being of significant importance statewide and nationwide as a symbol of Alaska received an Award of Merit from the American Institute of Architects.
Both Dawson Construction and Jensen said working on the project and restoring a historic landmark presented a once in a lifetime opportunity for them. This project was Dawson’s first construction management/general contractor project for the Legislative Affairs Agency, and they were thrilled with the successes for everyone involved.
“The team was incredible on all levels – from the owners and design team all the way down to the crew members,” said Dawson Construction. “Truly a notably special project.”