The biggest single pour Webcor Concrete Sr. VP Greg Miller remembers was about 8,000 yards. But the 5,622 cubic yards poured at the Potrero Power Station project — where construction of a UCSF Proton Therapy center is underway — added a unique layer of complexity that Greg says he'd never seen. "The shielding concrete had to meet a density higher than usual, and density testing is something that we've not encountered during my career," he says. "Having to pass a test for every single truckload of shielding concrete for density, temperature, and slump added extra pressure to the entire operation."

"It was something we’ve never done before," adds Construction Manager Joe Bell, "combining a many-thousand-yard mass concrete pour with a fifth of it being shielding wall concrete." The team had been preparing for it since August of last year.

The Shielding

The shielding wall concrete was poured around the rooms that will contain the 360-degree rotating gantries that revolve around patients during treatment. That's about 112 concrete trucks, and the temperature had to be perfect. "The temperature and density of the concrete in every single truck had to be tested before placement, which took a lot of extra special inspectors," Joe says. "I heard only three didn't pass muster. That was great."

By comparison, concrete temperature on a typical pour is tested only about every 17 trucks, and we usually don’t test for density,  Greg says.

The shielding sections also required a special pump truck designed for that purpose, with flags marking the shielding zones so only that pump could operate in those two areas.

Up Against the Clock

Altogether, 562 trucks rolled through in the roughly 24 continuous hours of work that began with setup at about midnight on Saturday, June 20; the first truck arrived at about 2 a.m. That many trucks required drivers from all over the Bay Area, as well as from Napa and San Jose.

Some challenges emerged early. The first truck required a mix adjustment, and one of the pumps broke down near the start, setting the schedule back. "We didn't plan to use all five pump trucks, but we knew we were up against the clock even more than usual with concrete," says Webcor Concrete Project Manager Kenny Hua.

Webcor Concrete Superintendent Kelly Martz picks up the story: "We saw it going so well that we fired up the fifth pump to help us catch up on time. But when drivers have to work that many hours, DOT restrictions apply, so we worked with Central to pull drivers from all over the Bay Area, plus Napa and San Jose. We were controlled at all times, never out of control." Once behind schedule, the team pivoted to bring in a backup pump. Interstate supplied four, Webcor supplied one, and Central Concrete staggered driver shifts to make sure no one ran out of legal driving hours before the pour was finished.

Five pump trucks ultimately rimmed the edge of the excavation, more pumps working at once than most people on the project had ever seen. The site itself was crisscrossed with about 1.2 million pounds of rebar.

"We poured out around 11:50 pm Saturday night," Kenny says. "The finishers were here through the night, putting in a lot of hard work" to finish the top surface.

Beating the Heat, From the Inside Out

Concrete doesn't sit still once it's poured. As it cures, it generates its own heat — and in a placement this size, that heat has nowhere to go.

"Concrete naturally gains temperature — that's part of the process," Kenny says. "But because the placement was so large, the concrete in the middle gets heated not just by its own reaction, but by all the concrete around it."

A pour this big falls into the category of "mass concrete," which comes with its own rules. If the core temperature climbs above 160 degrees Fahrenheit, the concrete becomes vulnerable to internal cracking that can compromise its structural integrity. So, before the first truck ever arrived, the team built a thermal control plan, modeling how hot the placement was likely to get, then setting limits to stay ahead of the risk.

A sensor buried at the core of the deepest section tracked the temperature throughout the pour and for days afterward, climbing past 100 degrees, then 150 — eventually peaking at 152. The testing of every truck pouring shielding concrete was designed to confirm that it fell within plan before it could be placed. The heat doesn't peak right away, either; it typically builds for seven to 10 days after the pour, so the monitoring didn't end when the trucks stopped rolling.

Once the surface was finished, the crew came back to cover the concrete with insulating blankets — not to warm it, but to slow how quickly it cools. If the core stays hot while the surface cools too quickly, the temperature gap between the two — more than 35 to 50 degrees, depending on conditions — can crack the concrete from the inside out.

"It's like tucking the concrete in for the night," Kenny smiles.

The Team

The team assigned to the project was supplemented with laborers and salaried personnel from several other Webcor projects, with 45 field laborers on site and 30 supervisors, ranging from superintendents to interns. Webcor Concrete Operations Manager Adrian Meraz spent much of the pour directing the pumps himself, holding the hose, holding the vibrator, doing whatever the moment required.

"The way the operation came together was very impressive," says Webcor Sr. Project Director Bill Fish. "Webcor Concrete was crushing it and setting an example for everyone else, and our subs followed suit." Bill singles out Southland and Cupertino, which spent the preceding weekends preparing for the pour. Representatives from Fifth Space, the project developer, were also on hand.

By pushing hard on overtime and weekend work over five weeks, the team pulled the pour forward from its original schedule by nearly a week, a compression Bill credits to Webcor Concrete's planning and execution, as well as the One Webcor mentality.

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The economics of a modern convention center are more layered than most people know. Conventions, meetings, trade shows, the steady drumbeat of events — that’s the business everyone sees. But it takes more for a facility like this to pencil out.

When the LA City Council approved the Los Angeles Convention Center expansion, the project’s value proposition went beyond new design features and Olympic readiness. The digital signage was a meaningful part of the picture. The six screens being designed and built into the façade are expected to generate substantial annual advertising revenue, an element that strengthened the overall business case for the expansion.

It's also what's keeping Raksha Nanaiah busy on a kind of project she never expected to be running for PCL-Webcor, the joint-venture design-builder delivering the LACC expansion.

Six Signs, One Coordinated Program

Raksha is the design manager for the digital signage scope at LACC, and she's wearing a second hat as project manager for the facade itself. The signage package comprises six screens in total: two freeway-facing and four facing Figueroa Street.

"The ones facing Figueroa are animation, full video," she explains. "The ones that face the freeway are static signage, because you don’t want to distract drivers with animation.”

The biggest of the six signs is, by any measure, enormous:50 feet tall, 483 feet long, and just under 25,000 square feet of LED in as ingle sign. It's not arriving on a flatbed. "The sign secondary structural frame comes in sections, so we build it on site," Raksha says. "The cabinets as well — they have to be built in sections on site. And then the modules are like 12 by 12 inches; each one can be carried by hand." No helicopter moment, no massive panel descending slowly from above.

The freeway-facing work is a major, multi-month build that is being carefully coordinated with the broader expansion schedule and the constraints around the requirement to meet the project schedule.

Retrofitting a Working Building

Five of the six signs are being mounted to the existing structure, which means that before any LED gets installed, "We have to remove the existing facade, strengthen the existing structural elements, install the sign frames, put the facade back, and then install the LED, "Raksha says.

It's all happening while LACC remains open for business. The building will be occupied and booked with events for the entire 18 months of construction. That puts most of the work on the night shift and makes coordination with LACC operations a daily exercise in maintaining egress, protecting attendees, and keeping the building running while a few thousand tons of structural steel and LED get bolted to its skin.

The installation deadline is March 31, 2028, but the signs won't go live then; they'll sit dark through the 2028 Olympic and Paralympic Games. The contract calls for testing and commissioning to occur after the Olympic pause period, with go-live in February of the following year.

A Year at City Hall

The technical work, as demanding as it is, has been matched by an equally important effort on the regulatory side: a city ordinance.

Digital signage of this scale, square footage, brightness, and refresh rate falls outside the existing LA code, so permitting the six signs involves an amendment to the City’s ordinance to address this new type of installation. That process began in May 2025 and involves review by the City Attorney’s office and the mayor’s final signature before the ordinance will be approved.

"It takes that long because of the brightness and sign square footage,” Raksha says. Proposed revisions address the refresh rate, among other things.

The freeway-facing signs loop in CalTrans because there are minimum-distance rules between freeway signs and square-footage thresholds that must be met. The Figueroa-facing signs are simpler — they just requiredirector-level approval from City Planning, which has been involved from early in the process.

Video rendering of freeway-facing signage

In parallel with the City Council process, the design team has been cycling submissions through the city’s plan check. Each submission draws detailed feedback from the city’s subject-matter experts across structural, electrical, mechanical, and architectural disciplines. The team works through that feedback, resubmits, and refines the package with each round. Permitted drawings will follow the council’s adoption of the amended ordinance, and the team is coordinating closely with the city to keep that sequence on track.

"It's been a process," Raksha says.

Applying Experience at a Larger Scale

Raksha brought directly relevant LED experience to LACC from the Los Angeles COSM project, where the team built the infrastructure supporting the LED scope. (COSM is an immersive entertainment venue in Inglewood, California, that uses a massive LED dome to present live sports, entertainment, educational, and cultural events.) At LACC, she is applying that background to a larger, more complex signage program, this time leading the installation side of the work as well.

"So now I’m getting that experience,” she says of a scope that has broadened her work well beyond the LED itself.

That's the part she keeps coming back to. The thing about a digital signage package on this scale, she says, is that it isn't really a digital signage package. It's everything around the LED.

"When we talk about digital signage, it's not a standalone system. It's not like a single system we're building. We're touching the existing structure. So, as a design manager, I'm gaining experience in retrofitting, and I'm working on key structural architecture. I'm looking at the design as a whole, not just the LED scope. From a learning standpoint, it's been a great experience for me. Although I'm doing the facade and the signage, I'm getting exposure to all of the scopes: MEPFs, utilities, structure, concrete, etc."

Why it Matters

When the screens light up alongside the broader expansion, most people who drive past on the 110 or walk down Figueroa won’t think about the ordinance work, the careful construction sequencing, or the structural retrofit hidden behind the façade. They’ll see the show.

What they’ll be looking at is a signature element of the expansion, one that helped strengthen the case for the project and now anchors the building’s new public face.

It also stands as one of the most technically demanding façade builds the PCL Webcor Joint Venture has taken on, and a showcase for the depth of experience the project manager and the wider team bring to it.

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Introducing The Jobsite Journal: a photo-driven publication capturing real moments across Webcor’s jobsites.

What started as an internal effort has evolved into a portfolio we’re excited to share with our clients and partners across the industry.

With this release, all three of our published volumes are now live on our website for the first time. Each volume immerses you in the action of select Webcor projects through on-site photography highlighting their progress and the teams making it all happen.

All photos were shot by Webcor Marketing Manager Brandon Blum. Explore the full collection: https://www.webcor.com/publications