www.concreteinternational.com | Ci | JULY 2019 51
SFO Long-Term Parking Structure
reduce the heat of hydration on the mass concrete used for the
project. The mixture produced sufficient heat, however, to
avoid delays in finishing and form removal. Seven-day
strengths reached 4000 to 5000 psi (28 to 34 MPa), while the
28-day strengths reached 7000 to 8000 psi (48 to 55 MPa).
Project Credits: Louisville Metropolitan Sewer District,
F.A. Wilhelm Construction Company, Uliman Schutte,
Leonard Engineering, Allied Ready Mix, and Skyway Cement.
SFO Long-Term Parking Structure, San Bruno, CA
The San Francisco International Airport set out to
demonstrate its leadership in sustainable building through the
use of concrete made with supplementary cementitious
materials (SCMs) for its new parking structure. The owner’s
goal was to reach gold level LEED accreditation. The
project’s concrete mixtures comprised 45% SCMs in grade
beams and pile caps, and 30% slag cement in all other
concrete applications. To meet the airport’s completion
deadline, the elevated decks required high-early-strength
concrete. The use of slag cement allowed the mixtures to meet
the SCM and high-early-strength requirements. As bonuses, it
resulted in impressive later-day strengths and significant cost
savings for the airport.
Project Credits: SIFA, Nibbi Brothers General Contractors,
Kwan Henmi/FMG Joint Venture, Buehler Engineering Inc.,
Graniterock, and Lehigh Southwest Cement Company.
Tappan Zee Bridge, New York City, NY
The Tappan Zee Bridge (officially the Governor Mario M.
Cuomo Bridge) is a twin cable-stayed bridge built to replace
the original Tappan Zee Bridge over New York’s Hudson
River. The new structure required almost 6 years to construct.
The bridge was designed for a 100-year service life and uses
slag cement in almost every portion of the structure, from the
mass concrete foundations to the top of the cable-stay
columns. Over 3 miles (5 km) in length and nearly 200 ft
Tappan Zee Bridge
(61 m) in width, the nearly $4 billion structure required
300,000 yd3 (230,000 m3) of concrete. Sixty-seven percent
slag cement was used for low heat in mass concrete to prevent
thermal cracking. Editor’s note: For more information on the
project, see “The New NY Bridge Construction,” Concrete
International, Sept. 2016, pp. 29-34, for which the author,
Brian P. Cresenzi, received the 2018 ACI Construction Award.
Project Credits: New York Thruway, Tappan Zee
Contractors LLC, HDR, and LafargeHolcim.
Charlevoix Cement Plant Expansion and Silo
Installation, Charlevoix, MI
St Marys Cement, part of the North American operations
of international building materials supplier Votorantim
Cimentos, recently expanded and modernized its Charlevoix,
MI, plant. The full scope of the project included a raw mill
upgrade, a new calciner, and kiln modifications. The most
innovative use of slag cement on the project was the 23,000 ton
(21,000 tonne) blending silo, which stands 160 ft (49 m) tall
and is 78 ft (24 m) in diameter. The silo was constructed in a
continuous slip-form placement that lasted several days.
While the concrete had to stay workable during placement, it