Because the 30-ft-tall, 7-ft-thick concrete walls had to meet extremely tight tolerances and be constructed without traditional ties to adjacent formwork, the team utilized advanced modeling technology to pre-visualize every element, identify any conflicts and plan strategies for detailed formwork.

To reduce the risk of thermal cracking during curing of the custom dense concrete mix, temperature sensors embedded throughout the vault monitored internal conditions.

Photo courtesy DPR Construction

DPR Construction’s self-perform concrete team worked months in advance with the structural engineer, design team, trade partners and DPR’s in-house BIM group to fully coordinate the vault geometry and embed layout.

The team used 3D modeling to visualize every element, identifying conflicts and planning the detailed formwork strategies. This early coordination ensured zero tolerance clashes during execution.

The radiation shielding requirements also demanded a custom dense concrete mix, increasing complexity. To reduce the risk of thermal cracking during curing, DPR brought in a concrete engineering specialist to assist in thermal analysis and mix design. Temperature sensors were embedded throughout the vault to monitor internal conditions, and thermal blankets were used to retain heat during winter.

Pour sequences were carefully limited in volume, allowing each lift to cure evenly and reduce internal stress.

Weather during the peak winter season added further complications. With freezing temperatures preventing concrete pours on multiple days, the team reprioritized work to focus on installation of the vault lid and sealing operations, helping keep critical-path activities on track.

Photo courtesy DPR Construction

Through a combination of precise planning, technical innovation and cross-discipline teamwork, the team successfully delivered the vault to specification, avoiding rework or structural issues.

Safety was a major focus, with contractors ultimately recording approximately 230,000 worker hours and zero recordable incidents or lost-time accidents.

An early and critical safety decision involved site access. While the original plan aimed to keep Atrium Health’s main entry to the Levine Cancer Institute open throughout the course of construction, an assessment by the project team showed this posed unacceptable risks to patients, staff and visitors.

Meeting with the project owner, the construction team proposed alternative routing options, and a decision was reached to close the facility’s main entry for the duration of the project.