San Francisco is home to more than 800,000 residents in less than 50 square miles. More arrive every year due to the tech boom in nearby Silicon Valley; other newcomers simply want to be a part of this vibrant and picturesque city on the Pacific Coast. To help meet the growing demand for homes, high-rise developments are transforming the skyline of the Rincon Hill neighborhood where abandoned warehouses once stood. CEMEX was recently a supplier to one of the most eye-catching examples.

The Lumina is a four building complex with 655 high-end residential units and retail space on a footprint of 75,000 square-feet. A 43-story story tower is connected to 38-story tower by two nine-story mid-rises. Built as the city was just coming out of an economic downturn, Lumina helped spark interest in revitalizing a neighborhood now home to several modern apartment buildings.CEMEX partnered with Webcor Concrete, Lumina’s concrete contractor, to complete each level in a three-day cycle. This meant within 72 hours, CEMEX trucks poured the deck and all vertical space, and then repeated the process the following day. All-in-all, CEMEX trucked in 100,000 cubic yards of concrete in just over a year.

CEMEX partnered with Webcor Concrete, Lumina’s concrete contractor, to complete each level in a three-day cycle. This meant within 72 hours, CEMEX trucks poured the deck and all vertical space, and then repeated the process the following day. All-in-all, CEMEX trucked in 100,000 cubic yards of concrete in just over a year.

Jeff King, CEMEX's senior territory manager for the Bay Area, said, “In order to meet the tight schedule, CEMEX used several specialty mixes – mostly accelerators so the deck cycles could complete on time and superplasticizers to get our mixes to the top of the 43rd floor.”

The design called for post-tensioned reinforcement, which allowed for a fast-paced construction schedule while using less material than a steel- or mild-reinforced concrete building. King said, “We had to wait until the concrete reached 3000 psi before they stressed the cables. If they couldn’t stress the cables as planned, the overall schedule would have pushed.”

To add to the challenge, a dense city like San Francisco can make the five-mile drive from the local concrete plant take 45 minutes. To keep the project on schedule, concrete was delivered from plants 20 miles away during light traffic.

“CEMEX was invaluable in providing us the service we needed and prioritizing the schedule,” said Webcor Project Manager James Shimamoto. “They opened their Oakland plant when necessary, stayed late and worked on weekends. The fact that we were able to build all of these structures on schedule using one concrete supplier is pretty impressive to me.”

As King put it, “Our relationship with Webcor is not just vendor and contractor. It’s a partnership built on teamwork. And that’s what it takes to build a structure like Lumina.”

The result: a jewel in a once-forgotten corner of the city. Architects Arquitectonica & Heller Manus wove in incredible detail, including private balconies with views of the nearby bay and a 70-foot lap pool in the fitness center. While it’s an easy walk downtown or AT&T park, homeowners have access to a fleet of Audis for their personal use when they want to venture farther out. Atop it all is a 10,500-square-foot rooftop terrace with a grill and fire pit.

Shimamoto said, “CEMEX has been instrumental in helping us design mixes that work with our fast-cycle schedules and construction needs. We’ve been doing business together for a long time. A lot of this neighborhood, and even this city, is here because of a Webcor Concrete and CEMEX partnership.”

“I’m extremely proud of what our Bay Area team accomplished at Lumina. This highlights how our project team and drivers can work together with our clients to solve several challenges – doing it all injury-free,” said West Region President Eric Wittmann. “The result is a stunning set of buildings that are transforming one of the world’s most remarkable cities.”