Utah's State Capitol

Jack B. Parson Companies created a safe and secure foundation for Utah's State Capitol with innovative concrete mixes and techniques

In 1912, The Utah State Capitol was designed by Utah architect Richard K.A. Kletting. His vision incorporated modern construction methods and materials including reinforced concrete which was state-of-the-art for his time. Kletting's award-winning plans included elevators, exquisite electrical lighting, and beautiful craftsmanship throughout. Kletting's masterpiece was completed in 1916, just four years from time of groundbreaking or conception to completion.

Fast forward to 2004 when major reconstruction and renovation work began on the state capitol. The project goal was to update the structure to meet modern- day building codes including significant seismic upgrades. The capitol needed a new foundation as well as a base isolation system to protect the building and its occupants from earthquake damage -- requiring millions of pounds of concrete.

That's when project general contractor, Jacobsen-Hunt, brought in Jack B. Parson Companies (JBP), a division of Staker Parson Companies, to supply specially designed concrete mixes used for the new foundation and base isolation system.

"We considered the opportunity to work on the State Capitol as a serious stewardship to help preserve one of the most significant and important buildings in our state" said Scott W. Parson, company president. "We dedicated our resources to provide technical expertise, innovation, and the service necessary to help meet the construction needs and schedules of our customers. This proved to be a real challenge given the cement shortage that hit during this project but we succeeded in helping keep the project on track."

Parson explained that his company created a special mix for the base isolation system that served as the keystone to the construction process throughout the project. The mix needed to produce 4000 PSI in 28 days and 5000 PSI in 56 days along with low heat of hydration and low shrinkage. The special mix had to bond to the existing structure and support it during the restoration. The low heat of hydration was necessary to protect the concrete from cracking during the curing and to safeguard the existing structure from undue stresses.

JBP used maturity meters embedded within the concrete to monitor temperatures throughout the curing process. The concrete was placed around the rotunda footings to support the Capitol dome and between all the supporting columns in the structure. After the concrete was placed, contractors jacked the entire building up off the original footings so the new foundation could be installed. For this portion of the project, JBP designed, tested, and provided high fly-ash (above 50 percent) mixes that included high range water reducers to achieve the proper design specifications. The mix supplied by JBP exceeded all design criteria.

A special mix that is classified as a self consolidating concrete (SCC) was used to support the base isolation piers. The building literally rests upon this mix. The design strength required was only 4,000 PSI but the strength went much higher, in some cases above 9,000 PSI. The concrete was designed to be placed with plasticity near the consistency of water. This allowed the concrete to flow and consolidate in and around any reinforcing steel without the use of vibrators. Jacobsen-Hunt also used this mix when it was necessary to quickly achieve strength.

Another challenge that demanded and innovation solution occurred when contractors needed to place concrete next to fragile areas without creating any damage, particularly where sheer walls were placed inside the existing granite fa?ade. JBP supplied a 4000 PSI low-slump shot-crete mix that was pumped and then sprayed into place. This mix was placed on all the walls that came in contact with the exterior fa?ade.

In upper sections of the building where the structure needed reinforcing without adding undue weight, JBP supplied a 3000 PSI light-weight mix that cured with a density of 110+/- 3 lbs per cubic foot.

Some areas of the building did not allow for proper access and forming practices in order to place standard concrete. That's when JBP used a mix design of 4,000 PSI 60/40 pea gravel mix with a high-range water reducer to promote flowability.

Certain isolated sections of the building required special admixtures such as DCI for high early-strength enhancement and Xypex for waterproofing. These innovative products were added as needed contributed to the success of this project.

"Our goal throughout the course of this project was to preserve the structural and architectural integrity of the building," stated Rod Higley, JBP Technical Sales Representative. "The Jacobsen-Hunt team was ideal to work with and they had a very well-orchestrated plan in place. We collaborated on the design of mixes, concrete per the specifications, and delivered according to the demanding schedule."

On January 8, 2008, at the re-dedication of the Capitol, architect David Hart, the man in charge of the $227 million renovation, said, "The quality of this historic restoration ranks among the best in the world."
Scott W. Parson added, "We were honored to be part of this great renovation project supplying world-class products used to build a safe and secure foundation for Utah's great State Capitol."

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