Mayo Clinic's proton therapy project takes big step this week

Workers take part in the largest concrete pour in the ongoing construction of the Mayo Clinic Proton Beam Therapy building along First Avenue Northwest Thursday, May 3, 2012. At nearly 6,000 cubic yards, it is the largest continuous concrete pour in Rochester history.

By By Post-Bulletin staff

May 02, 2012 at 11:29 PM

The largest continuous concrete pour in Rochester history was set to get under way Thursday morning as part of the construction of the Richard O. Jacobson Building.

The $187.5 million building being constructed at the southwest corner of Second Street Northwest and First Avenue Northwest will house four rooms for pencil-beam proton radiation therapy for cancer patients.

According to Knutson Construction, three concrete pumps will be working for 24 to 28 hours to complete the pour. The pour involves:

• 5,400 yards of concrete.

• 540 cement-truck loads.

• 60 workers.

• 256 tons of rebar.

The workers will do one or two shifts apiece at 30 workers per shift, with three shifts total.

Once the pour is complete, workers will apply a "finish" that will take another four to eight hours. After the finish is applied, the new concrete will be covered to prevent it from becoming too hot during this week's warm weather.

The thickest wall to be poured will be 21-feet, nine inches wide by 14-feet high. That wall is for the "gantry," which is the machine that delivers the protons to the patient.

Parking will be closed for the duration of the pour on Third Street Northwest between First and Second avenues; Seven Avenue Northwest between Third and Second streets; and First Avenue Northwest between Third and Second streets.