Drive down Airport Way between Lathrop Road and Daniels Street and you are passing over the second act for 13,800 discarded used tires.

Manteca used chip seal and asphalt mixed with rubber from pulverized discarded tires as part of the $2.9 million project in 2022 to address pavement quality issues along the Airport Way corridor.

“It holds up just as well,” noted Ken Jorgenson who serves as the City of Manteca’s Director of Engineering.                                                                                                                     

The Airport Way project used rubberized asphalt that was made by grinding up 12,655 used tires. Another 1,145 tires were used as part of the rubberized chip seal.

Case studies cited by Caltrans and Cal Recycle indicate when rubber from recycled tires is used it can extend pavement life as it helps reduce cracking.

Streets resurfaced in the Mayors Park neighborhood in the triangle bounded by Union Road, Louise Avenue, and the railroad tracks also included rubberized paving applications made in part from 6,899 used tires. That work was also done in 2022.

The technology of using pavement material with shredded tires has been around since the 1960s.

The addition of rubber gives the liquid asphalt greater viscosity or resistance to flow.

 It also improves other properties which resist reflective cracking and rutting, and prolong pavement life.

During the past 20 years through Cal Recycle efforts, the use of recycled tires in asphalt has become more prevalent in California.

The state’s motorists discard 40 million tires a year of which 30 million after being pulverized make their way into asphalt and chip seal that is applied to streets, freeways, and highways in California.

The push to recycle used tires is based on the fact buried tires do not decompose.

The rubber material also traps gases like methane, which causes them to bubble up to the surface after burial. Jurisdictions have banned the practice of throwing away tires to preserve room for other household and commercial garbage.

If tires are exposed to wind and rain, tires will eventually crumble, but they will ruin the soil they sit on.

The first streets to receive rubberized asphalt chip paving overlays in Manteca were Cottage Avenue from Yosemite Avenue to the Highway 99 overpass, Industrial Park Drive from Main Street to a point just east of Bessemer Avenue, and Center Street from Union Road to the railroad tracks. The resurfacing took place in 2008.
The city viewed the work as a pilot test to see how well the rubberized asphalt held up.

It has been in widespread use for streets since 1989 as it has passed muster in Arizona heat under heavy use as being just as durable as standard asphalt.

Based on how the original three streets were holding up, Manteca went ahead and used the rubberized asphalt chip overlay on East Yosemite Avenue as well as Moffat Boulevard in 2011.

Jorgenson noted the material doesn’t hold up well to excessive turning movements. That is why the rubberized material is not used in cul-de-sacs.

Research and data collected by various state transportation agencies show the rubberized asphalt pavement:
•reduces traffic noise by an average of four decibels although in some cases a noise reduction as much as 90 percent or 10 decibels has been attained.
•provides a smoother and quieter ride.
•is as durable and more skid-resistant than conventional asphalt.
•does not reflect cracks from the existing pavement.
•has an estimated life span of 18 years with many cases of pavement now 14 years old not needing any maintenance whatsoever.
Some cities in Arizona report feedback from joggers who have noticed the asphalt is somewhat softer — and therefore less jarring — than regular pavement.
About 1,500 used tires are recycled in9to asphalt every lane-mile of rubberized pavement.
Rubber is extracted from used tires by separating the casings, fabric, and steel. The extracted rubber is then ground to the consistency of ground coffee.

To contact Dennis Wyatt, email dwyatt@mantecabulletin.com