Project Delivery
Caltrans Shaves Months Off SR 99 Repair Time With Precast, Prefab Girders
One of the largest freeway closures in Sacramento history is underway as Caltrans aims to repair a busy section of State Route 99 in just 99 hours. The project began June 11 at 8 p.m., when the agency closed northbound and southbound SR 99 from 47th Avenue in Sacramento to the U.S. Highway 50 Connector. The freeway will reopen on June 16.
The $5.9-million “FixSac99” project will replace a 62-yr-old bridge deck on SR-99 at 21st Avenue.
To accomplish this in such a short window, Caltrans is using precast girders and accelerated bridge construction to shave months off construction. If the agency chose a different method, the project would require extended weekend closures, extensive traffic shifts and lane reductions, and take from six months to a year to complete, says Caltrans spokesperson Angela DaPrato, who notes this method has never been done in the Sacramento region on this scale before.
Caltrans is working with Lathrop, Calif.-based Con-Fab California LLC, which prefabricated 35 giant bridge-girder sections at its factory in Lathrop. The pieces are 51 ft-long, 48 in wide and 27 in deep. They weigh between 44,000 and 86,000 pounds. The work will be done by Bridgeway Civil Constructors, Inc.
“We can fabricate the product offsite within a factory environment to strict specifications and the product will then be able to arrive on the jobsite in such a manner that it is able to take traffic loading immediately as opposed to having to cure onsite,” says Michael Hein, president of Con-Fab California.
The sections are trucked to the jobsite and installed with two crane crews. Once they are in place, the joints between them will be sealed off and ultra-high-performance concrete will be installed within the keyways to lock the pieces together, says Hein. Once that is done, a polyester concrete will be put on top to smooth out any edges.
Hein says his company worked on an $800,000 contract to fabricate the pieces in about a month. Once the sections were complete, his team put them together at the Con-Fab plant to fit before taking them to the actual project site, says Hein.
The FixSac99 bridge deck replacement is part of the SAC 99 21st Avenue Project, which includes replacing sound walls, the concrete median barrier, and installing brighter lighting for the 21st Street undercrossing.
Built in 1959, the 21st Avenue undercrossing was band widened in 1974. It currently has corrosion on the surface deck, concrete spalling, cracks, joint seals that need to be replaced, and the bridge deck has begun to deteriorate due to wear and tear from high traffic, weather and age. Caltrans says it is replacing the bridge deck before emergency operations are necessary.
Caltrans used a similar accelerated bridge construction method on the $14.1-million project that replaced the deteriorating Echo Summit Bridge on U.S. Highway 50 in El Dorado County.
