One World Trade Center, built on the site of the former Twin Towers, stands as a global symbol of resilience after the 9/11 attacks. As the focal point of downtown Manhattan’s revitalization, the multi-purpose tower supports tens of thousands of people each day.

Following Superstorm Sandy, saltwater intrusion severely corroded the tower’s below-grade areas, threatening both safety and long-term durability. STRUCTURAL joined the Salt Damage Remediation (SDR) Program, a collaborative design-build initiative focused on preventing further deterioration, restoring structural integrity, and ensuring the building’s intended 100-year service life.

Detailed investigations were conducted to identify and assess compromised areas. Repair strategies were developed through mock-ups and performance testing to ensure all work could proceed while the structure remained fully operational.

One major effort involved repairing steel blast plates where voids existed between the steel and concrete. Using acoustic testing, thermal imaging, and selective drilling, STRUCTURAL crews located the problem areas, injected epoxy to fill the voids, and applied a high-performance protective coating to guard against future corrosion.

For chloride-contaminated slabs, the team mapped and identified damaged areas, injected epoxy under pressure to seal the cracks, and verified the repairs through core sampling. To further protect the structure, a two-coat elastomeric system was applied to concrete walls, sealing micro-cracks, preventing carbonation, and improving long-term moisture resistance.

This large-scale restoration effort not only repaired critical infrastructure beneath one of the world’s most recognized landmarks but also demonstrated how a collaborative, innovative design-build approach can deliver resilient, high-performance results. By combining advanced testing methods, proven corrosion control techniques, and careful project coordination, the work ensured the World Trade Center remains structurally sound and protected for decades to come.