The Trinity Landing retirement community in Wilmington, North Carolina welcomed its first residents in August 2022. Due to the development’s proximity to saltwater, PENETRON ADMIX SB, a crystalline concrete waterproofing admixture, was chosen to protect below-grade concrete elements.
A port city situated between the Cape Fear River and the Atlantic Ocean, Wilmington is known as a gateway to the Cape Fear Coast beaches, with four nearby beach communities just outside the city limits. With over 115,000 inhabitants, the city was declared one of a “Dozen Distinctive Destinations” in North Carolina by the National Trust for Historic Preservation. The city riverfront was also recently ranked as the "Best American Riverfront" by readers of USA Today.
Designed by SFCS, an architectural firm from Charlotte, NC, the Trinity Landing retirement community development is located just south of Wrightsville Beach and overlooks the Intracoastal Waterway. The 514,426 ft2 community spans two campuses; the initial phase of construction comprised 184 wood-framed multi-story apartment homes (800-1,660 ft2; 1–2-bedroom layouts), two-story villas (1,165-1,765 ft2), and a waterfront pavilion and boat dock. An additional 24 units will be added in late August during a second construction phase. Further amenities include three restaurants, a wellness center with a saltwater pool and spa, walking and biking paths, an auditorium, a library and media center, and meeting rooms.
Protection from a Seaside Location
Because of the proximity of the Trinity Landing jobsite to North Carolina’s Intracoastal Waterway, the combination of high groundwater levels and chloride ion exposure required a reliable – and waterproof – solution for the below-grade concrete foundation elements to ensure long-term durability.
“Both groundwater and chloride ion penetration are major causes of concrete deterioration,” explains Christopher Chen, Director of The Penetron Group. “Our local Penetron specialist showed how a solution based on integral crystalline technology would not only help streamline the construction schedule, but also guarantee a durable structure with an extended service life.”
Penetron worked with Crete Solutions, the ready-mix concrete supplier, to provide an optimal waterproofing solution. PENETRON ADMIX SB-treated concrete was used for the below-grade retaining walls and the elevator pits.
Becoming an Integral Part of Concrete
Easily mixed in during batching and unaffected by climatic conditions, PENETRON ADMIX SB quickly becomes an integral part of the concrete as the active ingredients in the admixture react to generate an insoluble crystal network. This crystal network seals voids and microcracks against water penetration, even under high hydrostatic pressure. Water is unable to pass through the crystal formations, making the concrete impermeable. Because the concrete is impermeable, chloride ion penetration is decreased, providing the much-needed corrosion protection in a coastal environment.
In addition, the self-healing capability of PENETRON ADMIX SB-treated concrete will self-heal and seal all hairline cracks that form throughout the service life of the concrete, reducing the amount of maintenance required,” says Christopher Chen.