Wilshire Grand Center Archives | Page 2 of 2

To successfully complete the world’s largest continuous mat pour, one of the biggest challenges Conco faced was to find ways to unload 120 – 150 truckloads of concrete per hour. With the need to unload so many trucks in such a short period of time, Conco’s plan called for thirteen points of placement in the mat foundation. However, only two sides of the project were accessible from the street.

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Since the site only provided access for seven pumps to be positioned to pump directly into the building foundation, Conco’s plan needed to have pumps that were pumping into pumps. Pumps were dropped by crane into the excavation site and two placing booms were fed from pumps nearly 400 feet away. In all, fifteen boom pumps, two high-pressure stationary pumps, two placing booms, and more than 2,500 feet of pipe operated throughout the pour to get the concrete to the foundation. Four of the pumps on this project were new along with a brand-new placing boom. In addition to this equipment, three boom pumps were parked in close proximity to the project in case of a breakdown. None of the backup pumps were put into service as the pumps on the job performed near flawlessly.

To complete the rest of this signature project, the two high-pressure stationary pumps will remain on-site for the project’s duration. One of the pumps is a recently purchased electric pump. This pump is the most powerful electric pump operating west of the Mississippi and is capable of pushing concrete to the top of the structure. It provides our client, the Turner Construction Company, with a zero-emission pump that operates with less noise than a typical diesel pump.

By the end of Conco’s record breaking mat pour, the pumping work all went successfully according to plan. Special recognition goes to our ACPA trained pump operators, and our mechanics that spent countless hours preparing the equipment for the pour.

*Photos provided by Gary Leonard

Starting at 4:47 p.m. on Saturday, February 15, 2014, Conco broke the Guinness World Record for the largest continuous mat pour in 18 ½ hours (1 ½ hours under the projected time). To verify the event, there was an official Guinness World Records adjudicator on-site. The mat pour was for the new Wilshire Grand Center that is being constructed in downtown Los Angeles, and is slated to become the tallest building in the U.S. west of the Mississippi.

*Photos by Gary Leonard

After some 5 months of excavation and shoring, Conco was finally ready to begin the preliminary mat foundation work. Starter footings and elevator pits had to be constructed before the nearly 7 million pounds of mat reinforcement was installed. Then came 18 miles of cooling pipes for thermal control. We were ready to go with a couple of days to dot the i’s and cross the t’s. We began the set ups for pumping which involved strategically placing 19 pieces of concrete placing equipment in and around the construction site. It was now time to place this nearly 20 foot thick mat foundation.

The massive mat pour required a fleet of 208 trucks that each made 10 to 14 concrete drops for a total of 2,100 trips over the 18 ½ hour period. All of the concrete was provided by eight concrete batch plants operating at full capacity and located within a 20-mile radius of the job site. The success of the pour depended upon everything going exactly as planned and with contingencies in place to reroute trucks around any traffic jams. Trucks had to arrive on time since concrete needs to be poured 90 minutes after it is mixed. Several streets in the area were closed off to traffic.

Prior to this record breaking event, the largest continuous mat pour had been for the Venetian Hotel in Las Vegas in 1999. During that event, 21,000 cubic yards of concrete were poured. For the Wilshire Grand, 21,200 cubic yards of concrete were poured with an official finish time of 11:30 a.m. Sunday morning. The skyscraper is expected to be completed in 2016 and opened to the public in 2017. The Wilshire Grand will be 1,100 ft. tall, to include a 900-room hotel, office and convention space as well as five levels of subterranean parking.

Conco has been given the opportunity to participate in another landmark project by providing concrete services for the new Wilshire Grand Center being built in downtown L.A. The new tower will become the tallest building in the United States west of the Mississippi. This is one of several of our large-scale projects in Los Angeles. Others include the recently completed 125 year old Hall of Justice retrofit, the new Federal Courthouse, a new 45 story cast in place building at 10000 Santa Monica, The iconic ARTIC transportation Center in Anaheim and several smaller projects.

The Wilshire Grand is being built by the Turner Construction Co., which is one of the largest construction firms in the U.S. This is not the first major project that Conco has partnered on with the company. In addition to other large scale projects, Turner Construction and Conco have partnered together in building the new San Francisco 49ers Levi Stadium.

Work on the new Wilshire Grand began in late 2013 and will be the biggest Los Angeles area project to-date for Conco. The plan calls for the largest monolithic mat foundation pour ever attempted. Over the course of approximately 18 hours, over 21,000 cubic yards of concrete will be placed. By the end of the pour, we will have completed a foundation that is nearly 20 ft. thick.

The project is on an accelerated schedule including the work Conco is doing. All of the concrete work will be “cast in place concrete,” which is labor intensive. We will be on a 4-day core wall cycle, which means that every 4 days, concrete for a new floor will be poured.

The Wilshire Grand is expected to cost $1 billion once it is completed in 2017, and includes a 900-room hotel, retail and office space. The building will stand 1,100 ft. tall. With safety in mind, and to protect from terrorist attacks as well as other types of emergencies, the core of the building will be made of concrete. The L.A. Times reports that “four-foot-thick concrete walls will surround a staircase at the center of the building for people to use in case of an emergency.”

Conco is a leading supplier of concrete services for the Western United States. We have built our reputation in the Los Angeles area with superior concrete formwork, reinforcing, place and finish, shotcrete and other ancillary services that benefit from our vast experience. Our concrete services include commercial, educational, parking and other construction development as well as public works projects and highways.