Western Emulsions recently developed a process called Texture Seal, which combines the PASS QB product with a simultaneous application of jet-black sand.
“It’s a one-step process that can mitigate the skid value concern,” says Noring.
Texture Seal provides all of the benefits of a fog seal, while adding a micro-texture to the surface that enhances skid resistance to the roadway for better road safety at higher vehicle speeds.
“While agencies are sometimes reticent to fog-seal busy highways and arterial roads due to the temporary loss of skid numbers, the Texture Seal process mitigates this concern, and in fact can increase a road’s skid resistance in certain instances,” says Vandermost. “Texture Seal does this without clogging the void structure of open or gap-graded pavements (OGFC), including rubberized (RAC) roadways.”
Texture seal was applied in the middle of Bishop both during the day and at night during the Hwy 395 project.
“The product worked well, prevented any loss of skid resistance, and reduced the risk of asphalt emulsion ‘tracking’ on tires from the treated areas to other portions of the highway,” says Vandermost.
Why Caltrans chose rejuvenating seals
Rejuvenating seals offer many benefits. They are an inexpensive way of arresting raveling and adding binder back into aged surfaces. Like other preservation techniques, the key is choosing the right treatment for the right road at the right time.
“You have to have a road in fairly good condition,” says Noring. “Rejuvenating fog seals will help with oxidation and maintaining the condition of the road, but there has to be very little damage to the pavement for it to be effective.”
The low cost of rejuvenating sealing is also attractive to agencies. “It’s pennies per square foot,” says Tedrow. “Compare that to the cost of a full rehab/reconstruct of a road and you can see how cost effective it is.”
Noring agrees that the low cost is a major beneift. “It’s amazing how much good a little bit of emulsion can do,” he says. “Fog sealing really beautifies a road — it looks like a new road when you’re finished. It’s inexpensive, transforms the road, and is done in a day.”
In Fiscal Year 11/12, Caltrans started to expand the use of a rejuvenating fog seal to help preserve its deteriorating road network.
“As one of the lowest cost treatments with the most ‘bang for the buck’, PASS QB is utilized by many maintenance areas across California and other states throughout the U.S.,” says Vandermost. “Used for many years by these Caltrans professionals with a proven track record of success, Hwy 395 has many sections that have received a PASS QB treatment and the pavement life extension is evident.
“If you take a road that’s in decent shape and treat it with a rejuvenating fog seal, you can get an additional 3 to 5 years of life before doing anything else to it,” continues Vandermost. “If you wait until the road needs resurfacing or rehabilitation, it’s going to be more costly and more disruptive.
“Agencies are doing a better job of identifying roads and maintaining them proactively instead of reconstructing them.”