The Conco Companies have been providing a variety of concrete services for the Salesforce Tower currently under construction in downtown San Francisco. Once completed in 2018, the $1.1 billion office building will be the center-piece of a new South of Market neighborhood that includes the Transbay Terminal. The scope of the project involved Conco completing two floors per week for the 61-story skyscraper, which was done in a 3-day work cycle for each floor in order to meet the accelerated pace.
To see how we accomplished this task, we encourage you to visit our facebook page to view our time-lapse video that depicts the last full core wall lift on the 1.4 million square-foot tower. Conco used a unique self-climbing form system that allowed us to do a pour cycle, also known as a “lift,” once every three days. As you will see from our video, the self-climbing form, which is secured to the existing wall below, made the concrete pours on upper floors very efficient. To allow access to the building’s 14-foot 9-inch floor-to-floor heights, the form was raised in increments of 15 feet, and involved both the exterior and interior sections of the system moving independently.
To complete a “jump”, the exterior sections require about 20 minutes to complete, and the more complex interior system takes about 45 minutes to complete a jump. Once it is in place, the crews aligned and secured the panels to allow the walls to be enclosed and ready for the pour. This innovative equipment allowed us to begin the next cycle just 6-8 hours after the pour was finished. The job also required using the most powerful concrete stationary pumps in the industry to pump the concrete to the height of the upper floors.
We recognize that this feat required absolute organization, management and execution from the top down including our hard-working, dedicated pump operators and rebar, formwork, and placement crews. In addition we are thankful for the support, partnership and collaborative efforts of the project’s general contractor, Clark/Hathaway Dinwiddie, a Joint Venture. Conco also acknowledges that we could not have done the job without the cooperation of all of our other trade partners as well as the project owner, Boston Properties, and our concrete supplier CEMEX.
The Conco Companies are a leading supplier of concrete services throughout the Western U.S. We got our start in the Bay Area in 1959 by offering clients the best value on a wide range of concrete services and products and are now one of the foremost concrete contractors in the region. Our concrete services include commercial, educational, industrial and public works projects as well as parking structures.