September 2020

Major Construction Milestone - Nighttime Deck Pour Over 101 Freeway

On the morning of August 1st, the Bureau of Engineering reached a major milestone on the Sixth Street Viaduct Replacement Project. During a six-hour closure of the 101 Freeway, crews poured three sections of the deck of the new bridge. Crews worked through the night and into the next day, pouring more than 1,100 cubic yards of concrete, totaling 130 truckloads. 
The hot weather that week added a challenge to the pour; if concrete gets above 90°F, it can lose its strength. So crews took the extra safety measure of pre-cooling the concrete by injecting liquid nitrogen directly into the concrete as it was being prepared in the mixing trucks.
The concrete then moved through the boom pumps to the deck below. The pour was a huge success and marks another milestone in the continuing progress of the Sixth Street Viaduct Replacement Project.

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The City of Los Angeles Bureau of Engineering is leading the construction of the new, $488 million Sixth Street Viaduct Replacement Project, the largest bridge project in the history of Los Angeles. The completed structure will be a 3,500-foot long viaduct connecting Boyle Heights and the Arts District across the Los Angeles River. The original viaduct was built in 1932, but had significantly deteriorated due to "concrete cancer"; it was demolished in 2016. The new viaduct will have ten pairs of lit arches, bike lanes and wider sidewalks, along with stairway access and bike ramps connecting to 12 acres of recreational and open space under the bridge. The bridge is funded primarily through the Federal Highway Administration, with additional City support. The viaduct will be completed in 2022.

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The Bureau of Engineering is the City's lead agency for the planning, design and construction management of the City's public buildings and its public infrastructure. Engineering is also responsible for managing permitting for all construction that takes place in the public right-of-way, as well as managing the City's state-of-the-art online mapping system, NavigateLA. Engineering is committed to designing and building environmentally-sustainable projects that include extensive community input. Engineering projects and services support the City's goals of creating a prosperous, livable and safe city for all residents and businesses.

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