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SOFIE Interior Alteration for PETtrace Cyclotron Bunker

Location: Haverhill, Massachusetts

Award: Durability

Project Team

Owner: SOFIE

Contractor: BOND Civil & Utility Construction, Inc.

Architect: Champlin Architecture

Engineer: THP

Concrete: J. G. MacLellan Concrete Company, Inc.

Slag Cement: Holcim

SOFIE, a manufacturer of radioactive isotopes, needed to construct a bunker similar to a bank vault inside an existing building to hold a 45,000 lb (20,500 kg) General Electric PETtrace Cyclotron and contain radioactive isotopes at its manufacturing facility in Haverhill, MA, USA.

The 550 lb/yd3 (326 kg/m3) cementitious pumpable mixture design called for 60% slag cement and 40% portland cement. The walls were 25 x 33 x 14 ft (7.5 x 10 x 4 m) tall and close to 5 ft (1.5 m) thick, with a slab for the roof to completely contain the bunker. The concrete achieved 4000 psi (28 MPa) in 7 days.

Slag cement was used because the project specifications required that certain placements be treated as mass concrete. Control of temperatures and temperature differences in these placements was required to minimize and prevent thermal cracking during the time of construction and to prevent a later-age durability concern.

Slag cement contributed to the project’s success by enhancing the pumpability, increased durability and strength, reduced permeability, and a much smoother finish and appearance.

Application Type

% Slag Cement Replacement


% Portland Cement


% Portland Limestone Cement

% Other SCM (if applicable)


Fine 1368 lbs/cy Coarse 2100 lbs/cy

Water/cement ratio


7-day strengths

4000 psi

28-day strengths

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