Caltrans launched a major improvement project earlier this year to repave northbound Interstate 680 between Koopman Road in Sunol and Alcosta Boulevard in San Ramon, and replace entire sections of the roadway to enhance safety and provide a smoother ride to motorists.
The goal of the NB 680 Rehab Project Sunol/Pleasanton is to rejuvenate the northbound lanes of this nine-mile section of freeway. Designed in three sections of three miles each, the first three-mile segment was initially going to be Precast Concrete Pavement (PCP), the second segment rubberized hot mix asphalt (RHMA), and the third segment PCP.
In August 2022, Security Paving Company was awarded the project and began their preconstruction research. The Security team surveyed the roadway and discovered that in the first three-mile section, lane 3 varied in width from 12 feet to 16 feet. This posed a significant problem as the Precast Concrete Panels come in a standard width of 11 feet 11 inches.
The paving crew sets the rebar in place in northbound lane 3 during the first full weekend closure.
Instead of going back to the panel manufacturer, Confab, to see if they could custom-manufacture the panels, Security Paving presented a Value Engineering Proposal (VEP) to Caltrans that changed lane 3 in the first three-mile section from PCP to Continuously Reinforced Concrete Pavement (CRCP) using Rapid Strength Concrete (RSC).
And to perform the CRCP paving work more efficiently over a shorter period of time, Security proposed full closures over three weekends, instead of traditional nighttime closures, essentially performing 1½ months of work in just 165 hours.
Working right behind the Wirtgen SP 64 paver, the paving crew smooths the freshly placed CRCP-RSC.
Caltrans reviewed and approved the VEP, and the innovative solution ended up saving Caltrans – and the tax-paying public – $1.6 million. It also enabled Security to widen the entire first three-mile section of lane 3 to 14 feet and reconstruct the shoulder.
“The Caltrans District 4 Team on the project was great,” said Project Manager Bassel Jamaleddine of Security Paving. “Chief Engineer Kum Senthil, Senior Resident Engineer Satinder Grewal, and Resident Engineer Eddie Dike all played instrumental roles in the success of this project.”
The completed, tined section of CRCP-RSC in lane 3 winds its way up through the Sunol hills.
“With a budget of $71 million,” Jamaleddine continued, “the scope of work now includes three miles of PCP in lanes 1 and 2 in the first three-mile section, with lane 3 changed to CRCP-RSC. The second three-mile section is RHMA for the three lanes, and the third section is three miles of PCP. For the entire nine miles of the project, there will be a complete shoulder cold plane pave.”
On Friday night, November 3rd, the Cat scoops up sections of the jackhammered old pavement. Photo courtesy of Caltrans.
The second closure recently took place over the weekend of November 3rd through the 6th. During the full weekend closure, the next section of existing deteriorated roadway was demolished and replaced with new pavement on southbound Interstate 680 in Pleasanton.
The rebar is set in place early on the morning of Saturday, November 4th in preparation for placing the new concrete pavement. Photo courtesy of Caltrans.
The schedule for the entire project covers 275 working days and is slated to complete in January 2024. Security Paving brought in a batch plant for efficiency, and is recycling all of the old concrete pavement. More than 24,000 cubic yards of PCP is going into place, along with 9,000 cubic yards of CRCP-RSC. A Wirtgen SP64 did the paving during the first weekend closure, and all of the new concrete pavement is being diamond ground. Ancillary work includes approach slabs, MGS, and drainage systems.