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Los Angeles: Guinness World Records for largest continuous Concrete Pour

AICHTAL/GERMANY, March 28, 2014 - At 73 stories and 335m in height, the new Wilshire Grand project in downtown Los Angeles will be the tallest structure west of the Mississippi when its doors open in 2017. Following deconstruction of the existing Wilshire Grand Hotel in 2013, construction of the new mixed-use building, designed by AC Martin Partners, Inc., commenced in February 2014 with the world’s largest continuous concrete pour. The project’s general contractor, Turner Construction Company (Turner), worked with The Conco Construction Companies (Conco), one of the largest pumping and belt companies in the U.S., to coordinate the fleet of pumps, including 16 Putzmeister America, Inc. (Putzmeister) units, required for the record-breaking, 16,200m3 mat pour.

Economic Impact

When Korean Air Lines Co., Ltd. (Korean Air) purchased the Wilshire Grand in 1989, the company recognized the need for world-class accommodations in Los Angeles, and planned to eventually create that true luxury flagship hotel in the internationally traveled city. As the largest Asian provider of air service to Los Angeles, Korean Air has had a significant impact on the region’s economy for decades. The Wilshire Grand project will continue that support by infusing more than $1 billion US Dollar (720 mio. €) into the local economy. It will create more than 11,500 construction jobs and generate more than $80 million US Dollar (57 mio. €) in tax revenue through the construction phase alone.

12 Putzmeister truck-mounted concrete boom pumps at the construction site of the Wilshire Grand Project in Los Angeles

During the massive pour, 12 Putzmeister truck-mounted concrete boom pumps ranging from 32Z-47Z Meters, two Putzmeister placing boom towers, and two Putzmeister trailer-mounted concrete pumps were strategically placed both inside and above the excavation. | photo: Gary Leonard.

Comprised of 900 four-star hotel rooms, world-class restaurants, retail space, and 400,000 square feet (37,200 m2) of new Class ‘A’ office space, once complete, the new Wilshire Grand will support nearly 2,000 new permanent jobs and contribute $16 million US Dollar (11.5 mio. €) in annual local tax revenue. The project will play a critical role in the city’s commitment to add 5,000 new hotel rooms citywide—contributing to 20 percent of that goal.

Record-Setting Pour

To lay the foundation for the massive Wilshire Grand project, Turner and Conco devised a plan for the continuous 16,200 m³ mat pour, which was located 24-29m below street level. For the past several months, crews have prepared the site by digging a 6m deep pit and lining it with 3700 tons of reinforcing steel.

During the massive pour, 12 Putzmeister truck-mounted concrete boom pumps ranging from 32 to 47 Meters, two Putzmeister placing boom towers, and two Putzmeister trailer-mounted concrete pumps were strategically placed both inside and above the excavation.

A total of 19 pumps were utilized for the pour. Six pumps at street level fed six pumps, including two Putzmeister MX 34-4 Placing Boom Towers, two 32-4- and a 36-4-Meter Truck-Mounted Boom Pump, located deep in the excavation. Two Putzmeister BSA 14000 Trailer Pumps at ground level also relayed concrete into the pumps located inside the excavation.

“We utilized Putzmeister equipment due to its durability and reliability,” said Michael Marchesano, Turner’s general superintendent. “With a continuous pour of this magnitude, you need to be able to count on your equipment to keep doing its job, even under demanding conditions.”

The pour included 227 ready mix trucks making more than 2,100 trips and pouring almost 39 million tons of concrete during an 18 ½-hour period. 

truck-mounted concrete boom pumps from Putzmeister at the construction site of the Wilshire Grand Project in Los Angeles


To minimize the impact on businesses and residents, the crew began the pour on a Saturday evening and concluded around noon the next day, working throughout the night.  | photo: Gary Leonard.

The structural engineering team, Brandow & Johnston, elected a continuous pour to ensure the mat foundation would yield the maximum strengths. To guarantee the entire pour cured at the same rate, a special C40, 90-day mix was used. Special admixtures were used to ensure the temperature during the process of hydration didn't exceed the parameters designed for the mix. Without those admixtures the mat slab could have experienced thermal cracking and lower strength, which could impact the structural integrity of the pour. Following the pour, a cure blanket and a thermal control system were put into place for 15 days.

The mat pour qualified as the largest continuous concrete pour in history and officially claimed a Guinness World Record.

Building Up
Now that the foundation is in place, the crew will begin working on the attached parking structure and 73-story building that will make up the Wilshire Grand project. Both of the existing Putzmeister MX 34-4 Placing Boom Towers that were used for the mat pour will remain in place while the crew builds up. Two additional Putzmeister placing booms will be constructed to help place concrete for the underground parking structure.

The two Putzmeister trailer pumps used on the mat pour also will be used to pump the concrete to the placing towers. Additionally, a Putzmeister Thom-Katt® TK 50 Trailer Pump will place shotcrete for the vertical concrete in the subterranean levels. The crew will be pumping more than 60,000 m3 of concrete vertically, including lightweight concrete and C55 mixes.
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