A roller compacts a layer of asphalt mix laid down by a Blaw-Knox PF 6170 rubber-tire paver.
This summer in opposite regions of California, two large repaving projects — a $47 million project to repave more than 1,000 city blocks in San Diego, and a $74.3 million rehabilitation project along I-680 in Contra Costa County — will be underway.
Both of these projects are long overdue, as the city of San Diego has been notorious for having some of the worst street conditions in the nation, while for years commuters along the heavily-traveled portion of I-680 — which spans from San Ramon to Walnut Creek — have requested rehabilitation work.
For San Diego, the repaving of more than 134 mi. (216 km) of damaged streets represents the largest repaving project in the city’s history, and nearly equals the amount of asphalt resurfacing work performed during the previous eight fiscal years combined.
“It’s definitely an ambitious project,” said Mayoral Spokesman Alex Roth. “It’s no secret that some of our streets are in dire need of fixing.”
Asphalt overlay work began in late April 2010. As part of the project’s first contract — valued at $11 million — SRM Contracting & Paving will complete asphalt overlay work on 111 city streets before January 2011, according to Rick Fouquette, SRM’s general superintendent.
On each street SRM first completes base repairs to the distressed pavement, followed by header cuts along the side of streets. The header cuts are part of the edge milling process, which is followed by asphalt overlay and roadway striping. On streets that serve as major thoroughfares, SRM will set up traffic loops prior to edge milling.
Throughout the project, SRM will utilize a company-owned Blaw-Knox PF 6170 rubber tire paver that features a standard paving width of 10 to 18 ft. (3 to 5.5 m), Fouqette said.
Other equipment currently being used onsite includes an Ingersoll Rand DD-90HF breakdown roller, an Ingersoll Rand PT125R pneumatic rubber tire roller, and a Hypac C350 finish roller.
As part of the $11 million contract, SRM will perform overlay work on several major city streets including Balboa Avenue — from Genesee Avenue to I-805 — and a stretch of Harbor Drive beginning at 32nd Street.
“The only challenge with larger streets is controlling traffic and protecting the crew from drivers,” Fouqette said, adding work often occurs several feet from traffic.
When work covered under the $11 million contract is completed, SRM will have used nearly 67,000 tons (60,781 t) of .5 in. (1.3 cm) city mix asphalt for overlay; and 10,000 tons (9,072 t) of .5 in. city mix asphalt for base repairs.
Major streets that will be repaved as part of future contracts include stretches of Mira Mesa Boulevard, Spring Canyon Road, Carmel Mountain Road, La Jolla Village Drive, Nobel Drive, Morena Boulevard, Aero Drive, Soledad Mountain Road, Richmond Street, and Hotel Circle North.
A tentative completion date of summer 2011 has been set for the entire repaving project.
In addition to the 134 mi. of asphalt-overlay, the city will be performing slurry-seal resurfacing on an additional 147 mi. (237 km) of roads. Slated to cost around $15.5 million, slurry seal work will tentatively be completed by spring 2011. A contract for the work has yet to be awarded.
Nearly 500 mi. to the north of San Diego in Contra Costa County, a $74.3 million roadway rehabilitation project that will repave, repair, and upgrade 100 lane mi. (161 km) of Interstate 680 is scheduled to begin in late summer.
Focusing on a busy 12.8-mi. (21 km) stretch of I-680 that passes through the cities of San Ramon, Danville and Walnut Creek, the project is currently advertised and out for bid.
Broken into two portions, the project entails improvements to the freeway’s concrete slabs, barriers, ramps, shoulders, HOV lanes, auxiliary lanes, and bridges.
“It’s something that’s been desired by the community (for a long time),” said Allyn Amsk, public information officer for Caltrans District 4.
The northern portion of the project, which runs from Diablo Road to Rudgear Road, will include a “crack and seat” operation and a 0.9-mi. (1.4 km) extension of the southbound, I-680 HOV lane.
Used during this portion of construction will be a special crack and seat machine capable of cracking 3 lane mi. (4.8 km) in 8 hours.
“It’s quite a bit quicker (than older crack and seat machines),” Amsk said, adding other crack and seat machines typically crack one lane mi. (1.6 km) in an 8-hour period.
After the concrete roadway has been cracked, commuter traffic will seat the roadway by driving over the “micro-cracks” created by the machine. The roadway will then be paved using rubberized asphalt derived from used tires.
Additional aspects of the project’s northern portion include replacing freeway barriers; repairing and repaving on/off ramps and freeway shoulders; replacing bridge approach slabs and bridge hinges; and repairing bridge deck surfaces.
Running from Alcosta Boulevard to Diablo Road, the southern portion of the project focuses on replacing failed freeway, mainline concrete slabs; and grinding and repaving HOV lanes.
Grinding all concrete paving and repairing on/off ramps and freeway shoulders also are significant aspects of the project’s northern portion.
During both portions of construction a significant amount of night work will be conducted and freeway closures will occur. Currently Caltrans has permission to conduct 33-hour, partial roadway closures on the weekends.
“This is a very busy freeway and always has to be open for traffic,” Amsk said.
Besides the utilization of rubberized asphalt derived from used tires, there are other “green” aspects of this project such as crushing demolished concrete into usable base material.
Additionally, areas under new guardrail will be treated with landscape fabric and concrete to eliminate weed growth; and the need to use herbicides for fire control.
Throughout construction — which is set to run until winter 2012 — all areas subject to erosion will be treated in order to eliminate sediment from reaching storm drains and waterways.