Engineered Solutions: Precast Concrete Highway Slabs Expedite Caltrans Project
Precast concrete highway pavement slabs are increasing in popularity for rapid highway construction. This is, in part, the result of many state departments of transportation recognizing the efficiency of the precast slab method and selecting it for use on an increasing number of state projects.
The California Department of Transportation (Caltrans), for example, has specified precast concrete pavement slabs for one of the largest projects of this type in North America: the Pavement and Slab Replacement Project on the Foothill Freeway (I-210). This transportation project, approximately 12 miles north of Los Angeles, begins at the Dunsmore Ave. undercrossing in La Crescenta-Montrose, Calif., and extends to the North Los Robles Ave. overcrossing in Pasadena, Calif.
Flatiron West of Chino Hills, Calif., appointed Oldcastle Precast (www.oldcastleprecast.com) of Fontana, Calif., to supply several thousand precast highway pavement slabs for this $148 million project.
For the 9.7-mile segment of I-210, Oldcastle Precast received a contract to manufacture 6,500 precast concrete pavement slabs. Each slab measures 12.5 feet wide by 11.33 feet long by 12 inches thick, and they will be used to replace sections that have undergone erosion and deterioration due to years of exposure to heavy traffic.
Site installation of the pavement slabs is occurring as an overnight process. The highway is closed at approximately 9:00 p.m., the deteriorated sections are cut out, and a lean concrete base is placed into the opening. After the concrete base achieves the required strength, approximately one hour later, the precast concrete pavement slabs are installed, and the highway is reopened for full traffic by 5:00 a.m. the next morning. This method reduces impact to the public, especially commuters.
Length of freeway segment: 9.7 miles
Total amount of concrete: 200,000 cubic yards of precast and cast-in-place
Average number of slabs set per week: 280
Average distance of slabs set per night: 630 linear feet
Manufacturing time: April 2016 through March 2017
Average slabs cast per day: 30
“Our team took an innovative approach to this project, drawing on our many years of experience, which resulted in a successful outcome for all,” notes Todd Ebbert, Oldcastle Precast’s regional general manager for Southern California. “This product offers a solid solution to improving our highways while creating little impact to the public.”
As has been seen through the years where precast pavement slabs are used to repair damaged highway lanes or upgrade older lanes, precast concrete pavement systems promote construction methods that reduce traffic congestion, reduce project duration, increase safety and produce durable repairs. Not only do the highway slabs install quickly, minimizing closures and exposure of crews to live traffic, they can be installed in any weather and last a long time, an estimated 50 years, per Caltrans.
This project started in April 2015 and will continue through mid-2018, including day and night operations. When completed, these highway improvements will enhance safety and meet current Caltrans standards.