What is the World’s Largest Concrete Pour?October 10, 2014
This year has seen a new record set for the largest ever continuous concrete pour, as part of the foundations of the new Wilshire Grand Center hotel and office complex were laid in Los Angeles. Previously, the record has been a contentious subject, with the pour for the foundations of Las Vegas’ Venetian hotel in 1997, recorded as 21,000 m³, and the 2007 pour for the foundation of the Landmark Tower in Abu Dhabi at 20,927 cubic yards, both laying claim to being the largest.
Located in LA’s down-town financial district, the Wilshire, at 1,000 feet, will become the tallest building in the US west of the Mississippi. The 73-storey hotel will open to guests in 2017, and with its distinctive “Mohawk” crest and spire, it will be a stunning landmark. The Wilshire is the first building to be built in LA without a flat roof for a helipad for many years, as a requirement for tall buildings to have rooftop egress has recently been lifted. The complex is being built by the Korean Hanjin Group, who own Korean Airlines.
Michael Empric, the official from Guinness World Records, was there to see the record established. He said that the operation went “about as picture perfectly as they expected”, and added, “it was kind of like a ballet of trucks, moving in and out all night, to get this record done.” As the site took up most of the lot, disruption to LA traffic during the concrete pour was inevitable, but kept to a minimum. Spectators watched from a public viewing platform on Wilshire Boulevard.
The carefully-choreographed concrete pour began at 4 pm and took more than 20 hours in total to complete. Concrete was delivered from 8 plants around Los Angeles throughout the day. A fleet of 180 trucks made multiple deliveries to the site, bringing in 2,100 truckloads of concrete in total. At any given moment, 16 trucks were simultaneously delivering their concrete to the site.
The 21,200 cubic yards of concrete weighed 84 million pounds when dry. Because drying concrete undergoes an exothermic reaction, crews had to run 19 miles of refrigeration piping through the concrete to keep it cool so that it did not crack. 24 sensors were embedded to monitor the temperature as the concrete dried.
Architects A.C. Martin claim that the single-pour process will improve the structural integrity of the Wilshire. The building will also include other interesting structural features, including seismic precautions consisting of enormous steel towers supporting the tower floors that surround a concrete core. In the event of an earthquake, they will “slide” around and support the stationary core. CEO and chief architect on the super-tall build, Chris Martin, said “This project will reshape how people think about luxury and class in Los Angeles.”
On any large project, aside from the one-pour process, there are many benefits to volumetric concrete. Concrete can be mixed on site, so there is no risk of over-ordering. Ingredients are stored in separate compartments so that the mix can be tailored to site requirements and weather conditions on the day. There is no waste, saving time and money, and volumetric concrete also eliminates the time-frame problem associated with drum-mixed concrete, which, once mixed, has to be delivered and used quickly.
Written by Roadmaster Concrete Mixers; the leading supplier of volumetric concrete mixers across the UK and Europe.