slurry seal – With over $1 billion in street repairs needed across Long Beach, a new crew in the Public Works Department is working to preserve city streets and keep them from falling into disrepair.
The “slurry seal” team, which started as a pilot program last year, consists of about eight to 10 people who travel through the city with a truck that deposits slurry—an emulsion of recycled rubber and asphalt—onto streets in need of repair.
After the truck dumps the slurry, the crew must then work quickly to spread it on the road with mop-like tools to ensure it’s evenly applied and that doesn’t run into the gutters. It’s a preventative step to help keep well-rated streets “good” as the city does more intensive work on streets in worse condition, which are more expensive to fix.
While the team started as a pilot, it now has structural funding to continue its work of layering the 3/8-inch thick emulsion on city streets, which improves the aesthetics of the roads by fixing “alligator cracks” but also keeps out one of the streets’ biggest nemesis: water.
“The purpose of the slurry seal is to make sure water doesn’t get into the sub-grade,” said Mark Wright, a bureau manager with Public Works who oversees the slurry seal program. “Instead of going around and fixing potholes, this is meant to minimize them so they never develop.”
Wright said last year the team sealed 9 million square feet of city streets, which was split evenly across the nine City Council districts to ensure that there was a level of fairness in what streets were being addressed.
That amounts to about 120 lane miles per year, Wright said. Wright added that every 100 lane miles of slurry seal divert about 26,000 tires from being sent to a landfill, because they’re ground up and added to the blend that the crews slather onto the street. The process can extend a street’s lifespan by about five to seven years.
Officials are hopeful that this program will give the city a chance to “stop the bleeding” when it comes to street conditions because the worse condition a street is in, the more expensive it is to repair.
A slurry seal can cost as little as $2 per square foot, according to the department’s website. However, a complete reconstruction of a failing street can cost $20 per square foot. Larger “complete street” rebuilds of major corridors can cost tens of millions.
But there are some limitations to the program.
Good, dry weather is a requirement, and the temperature outside needs to be at least 65 degrees for the slurry to be properly set. If a road is too wet, residents haven’t moved their cars off the street or the street has too much debris, crews have to spend time sweeping up trash, drying the road segments and getting people to move their cars before the seal can be applied.
“A temperature below 65 degrees is an issue,” said Rob Fiege, a construction service officer with Public Works. “The product takes too long to set, and we try to have the roads reopened by 6 p.m. It could take up to 48 hours if it’s too cold.”
It also can only be applied to streets with a pavement condition index score of 70 or higher. The city’s average PCI score is 56.
Fiege said that with good weather, the slurry typically sets in about six hours, so workers are assigned to monitor the stretches they’re working on to ensure that drivers aren’t bypassing the road closures and compromising the newly applied slurry.
That happens about three to four times per week, Fiege said, noting that tire marks left in the slurry seal typically go away in a few days, but the damage done to the foundation does not go away. If someone drives over the slurry seal before it’s set, it’s typically where they’ll see the street fail first in the future.
Because of the persistent rain the city saw earlier this year, “slurry seal season” was pushed back.
For Long Beach, “slurry seal season” typically stretches from March and November, but this year crews didn’t start their work until mid-May, Fiege said.
The city has proposed spending about $4.5 million in residential slurry seal work over the next three years in its capital improvement budget as part of the overall $100 million the city plans to spend on other residential street repairs over the next few years.
Wright said that the slurry seal team is part one of a three-part process; the city also plans to bring both an in-house concrete repair team and a grind-overlay team into the fold.
The concrete repair team would allow city workers to fix things like sidewalks that have been pushed up by tree roots as well as other accessibility issues, while the grind-overlay team could allow city crews to complete more extensive street repair work, which is currently contracted out to private companies.
“Our service will be better because we’re service-driven, not profit-driven,” Wright said.