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Caltech Smarts

California company “brings it all” for Caltech neuroscience building construction.

It’s called playing to your strengths. Hospitals have the best surgeons covering the toughest disciplines; legal firms will appoint their best litigator to the hardest cases; baseball teams facing a challenging opponent will turn to their ace pitcher. Simply put: if you want to ensure success, go with what’s proven successful in the past.

That was the rationale when Fleming & Sons Concrete Pumping landed a project working as subcontractor to construction giant Hensel Phelps for construction of a neuroscience building on the Caltech campus in Pasadena, California. Though the Santa Ana-based firm owns and operates a mixed fleet of more than 30 boom pumps, to mitigate any risk of an unforeseen delay or breakdown, they pulled from an available arsenal of Schwing pumps. It was a sound decision: In spite of some logistical challenges, more than halfway through the project, work on the three-story, 150,000-square-foot structure is proceeding nicely, on pace and without incident.

When in doubt, play to your strengths.

 

 

The Fleet’s In

Often ranked as one of the world’s top-ten universities, the California Institute of Technology (Caltech) is a private, doctorate-granting, research university, famous for its strength in natural science and engineering. In 2016, philanthropists Tianqiao Chen and Chrissy Luo, deeply committed to efforts to better understand the brain, gifted $115 million to create the Tianqiao and Chrissy Chen Institute for Neuroscience at Caltech. Construction of the new $200 million facility that will house the Institute’s labs, offices and administrative function began in 2018, according to Rich Grainger, the pumper’s manager of sales/service.

“Though we value every project and ultimately see ourselves as a customer service-driven company, we were especially aware of what we needed to bring to the table for this job,” said Grainger. “I went into it with a simple plan: Provide Hensel Phelps with what I view as our best pumps. I wanted reliable equipment on site that, should something unforeseen happen, would allow me to still make things work, keeping the project on track. We always like to have a Plan B available to us and not all manufacturers’ pumps provide that.”

For the Chen Neuroscience Research Building project, the pumper used a fleet of Schwing pumps, including a large portable trailer pump, and seven boom pumps ranging in size from 28 meters to 65 meters.

Hensel Phelps broke ground on the new complex in December 2017 and performed excavation/site prep throughout 2018 before beginning the concrete pumping facet of the job in late fall.

“We started with a series of six massive spread beam footing pours which ranged from 400 to 1,000 yards each, followed up with grade beams at the basement level, then moved on to the slab,” said Grainger. “With thicknesses that ranged from 12 to 18 inches, the slab was split into four separate pours that contained anywhere from 450 yards to 650 yards each.”

Tunnel Vision

Also situated at the subgrade level was a pedestrian tunnel which will connect the Chen building with the adjacent Broad Center for the Biological Sciences. The link is more than just a physical structure; it is designed to strengthen partnerships between the researchers of both buildings.

“This was a pretty sizeable walkway,” said Grainger. “It measures 80 feet long by 25 feet wide and has walls that rise up about 30 feet. However, when the time came to pump, there were some huge beams and shoring in place that were making access tough. So, pouring from the top, we reached 30 feet down, brought the tip through the beams to get to the back and just kept ‘hop-scotching’ over and through those beams to get the pour done. The articulation on that four-section 28-meter pump with the double 270-degree Z boom made all the difference.”

Limited space from which to operate was, in fact, the biggest challenge the pumper faced at the Caltech jobsite. Despite a fairly sizeable footprint, Grainger said that they had just three points of access for the whole job.

“There were crane pad sets in a number of locations, so we were told where we could access the site and asked if we could make it work—of course we said it was fine. But we were essentially booming into a hole and there always seemed to be an obstacle in the way, be it columns rising 30 feet into the air, guy wires stretching from column to column, whatever. Yet, we were still able to get to all parts of the job. We occasionally added 40 feet of hose or so to hit a corner, but the rest was all machine.”

Wall shoring also proved problematic. Because the company had to set up anywhere between 10 and 20 feet off any shoring, setting the pump up on trench plates was commonplace. “So, it always came down to numbers on reach, load on the outriggers, and so on, to ensure the customer had the right machine for the job,” added Grainger. “Luckily for us, we had a broad range of pump sizes available to us to meet those needs.”

 
Ice, Ice Maybe

As this story is being written, the pumper is preparing to begin work on the structure’s pan decks, which vary from four to eight inches thick. According to Grainger, he anticipates handling the first few pours with the S 28 X—again, to have the articulation they need— then move to a five-section S 38 SX pumping through 250 to 300 feet of system. Because summertime temperatures in the Pasadena area can get extremely hot (110° to 114° F is not uncommon), he tells his crews to be vigilant about the concrete.

“I remind our guys that, if they shut that pump off and don’t have concrete within five to 10 minutes, they need to swing it around to recirculate,” he said. “The heat and higher strength value of the mix combines to literally bake the concrete in that pipe. We will probably have to ice the mix for the deck pours because the concrete going in is a 4,000 to 5,000 psi lightweight mix, and if the aggregate for that mix is not soaked for about two weeks prior to the pour, it can go into the hopper with a slump of five inches and come out at two inches at the end of the hose. The heat just sucks the water right out of it. But our supplier, Robertson’s Ready-Mix, working out of their Irwindale location, is one of the area’s best, so I don’t anticipate that will be a concern.”

While the bulk of the concrete being poured fell into the 2,500 to 5,000 psi range, many of the structure’s columns and vertical walls used a plasticizer-enriched, 6,000 psi mix for added strength. In addition, the mix used for the slab and the decks employed a water reducer.

“As a whole, the engineers wanted the various mixes to be pretty dry,” said Grainger. “We were allocated a four-inch slump with five-inch maximum. But it really didn’t matter—the pumps, all equipped with Schwing Rock Valves, ate it up like it was candy.”

 

Over and Above

While their performance on the Chen Neuroscience Research Building project might bode well for landing future work, Grainger is quick to point out that their approach in Pasadena was actually textbook Fleming.

“Our philosophy has always been built around a concept of providing the best possible service,” he said. “A huge part of that means listening to the contractor, knowing what they are looking for, and meeting—or anticipating—their needs. That extends both to the higher caliber operators we employ and the quality of the equipment we bring to the job site. On this job, in advance of every pour, no matter the size, I would call or text the project superintendent to confirm that the pour was still on, the size of pump allocated to that pour, the volumes of concrete that would be involved, times and more. The customer would then verify that info and everyone’s bases were covered. That extra effort not only serves to confirm matters, it also eliminates errors or miscommunication. This has been a great project to work on and knowing we played a role in helping bring a facility like this to life is a really nice feeling.”

Fleming will be pumping into the November through January time frame; the Chen Neuroscience Research Building is expected to open in the fall of 2020.

 

 

Specs:
Project: The Chen Neuroscience Research Building
Owner: Caltech, Pasadena, California
General Contractor: Hensel Phelps, Los Angeles, California
Concrete Supplier: Robertson’s Ready-Mix, Corona, California
Contractor Pumper: Fleming and Sons Concrete Pumping, Santa Ana, California
Equipment: Schwing SP 9500 trailer pump, Schwing S 28 X; S 32 X; S 39 X; S 46 SX; S 58 SX; S 61 SX; and S 65 SXF truck-mounted concrete pumps with placing booms