Opened in May 2022, the 790 Foothill mixed-use complex in San Luis Obispo, California (USA), offers apartment units as both student housing and for low-income families. PENETRON ADMIX SB was specified to waterproof and protect strategic below-grade concrete structures from the site’s high groundwater levels.
The 790 Foothill multi-use complex on the main thoroughfare leading to Cal Poly — California Polytechnic State University, a public university – features 78 apartment units conceived as student housing, with 12 units reserved for low-income households, and 6,800 ft2 (620 m2) of ground-floor commercial space. Designed by Arris Studio Architects, the project layout features nearly 2,000 ft2 (185 m2) of space for the lobby and amenity areas, garage parking, and 123 parking lifts (integrates a hydraulic lift for single-space, below-grade parking to accommodate two cars). The residential portion includes eight 3-story wood-frame buildings totaling 83,334 ft2 (7,576 m2) which are connected by a network of breezeways and courtyards. The amenities include a rooftop deck and multiple student function rooms.
Construction of the partially submerged 51,561 ft2 podium combines below-grade concrete structures with heavy timber primary structural members. Work at the site was initially confronted with groundwater issues. Based on Penetron’s previous success in the region, Cal Portland, the project’s ready-mix concrete supplier, tapped Penetron for a durable concrete waterproofing solution.
“Penetron has worked with Cal Portland on numerous projects in the past,” adds Christopher Chen, Director of The Penetron Group. “After discussions about the project parameters, PENETRON ADMIX SB was quickly approved.”
Cal Portland added PENETRON ADMIX SB to the concrete mix for the perimeter walls and elevator pits, and PENECRETE MORTAR, a crystalline waterproofing mortar, was applied to seal the corresponding tie holes.
Added during the batching phase and unaffected by climactic conditions, PENETRON ADMIX SB is one of the world’s most efficient and economic permeability-reducing concrete admixtures for hydrostatic conditions (PRAH). PENETRON ADMIX-treated concrete is protected against a range of factors that cause concrete deterioration: freeze-thaw cycles, chemical attack, corrosion, and alkali silica reactions (ASR), while blocking moisture penetration resulting from hydrostatic pressure.
“As a proven waterproofing solution, Penetron’s crystalline technology is recognized as a reliable, value engineering solution,” adds Christopher Chen. “It’s easy to implement and also saves time during construction, which helps accelerate the schedule without sacrificing performance and quality.”