Delta Mist
Delta Mist® Penetrating Asphalt Spray Rejuvenator Seal
Developed by the Warner Babcock Institute for Green Chemistry (WBI) under the leadership of Dr. John Warner, Delta Mist extends the life of asphalt pavements by using small molecules in a carrier oil to interact with oxidized components in aged asphalt.
Delta Mist is a liquid, non-toxic, spray-applied, penetrating seal that restores oxidized asphalt, reduces the loss of fines and aggregates, and slows the oxidation process for a minimum of 3 years after application. However, Delta Mist is still undergoing testing by NCAT, and early results suggest that its effects on pavement longevity may extend beyond 4 years, showing promising long-term benefits.
Unlike other spray treatments, Delta Mist doesn’t clog the voids of open graded friction courses, allowing them to maintain the same high-void structure and friction characteristics after application.
Key Features:
- Penetrates up to 3/8 inch to restore oxidized asphalt by softening the binder and improving cohesion to retard crack propagation.
- Non-toxic, and non-hazardous.
- Does not require sanding or aggregate cover.
- Leaves traffic markings visible and reflective.
- Ensures no loss of surface friction characteristics.
- Allows traffic to resume within 60-90 minutes based on ambient temperature and humidity.

National Center of Asphalt Technology (NCAT) Test Track Study Results
Delta Mist was tested alongside other top-performing rejuvenators over a -year period on low-volume, thin-lift pavements.
Evaluation included high, intermediate, and low-temperature binder performance, rutting, cracking, friction, and visual assessments.
After 20 million ESALs and 6 years of testing, Delta Mist was the last rejuvenate still in service, and selected for further study.
Key Statistics
Cracking Performance:
- Minimal cracking (<0.2% block cracking after 20 million ESALs).
- Delta Mist extended pavement life by several years, maintaining performance beyond standard specifications.
Rutting:
- Depths remained at 3.8–5.3 mm, far below the 12.5 mm failure threshold.
Friction:
- Initial drop in friction was minimal; recovery was rapid and sustained for 48 months.
Softening Effect:
- Binder viscosity consistently reduced, improving flexibility and reducing cracking susceptibility.
Glover-Rowe Index & Longevity
The Glover-Rowe Index is a measure of asphalt binder stiffness and cracking susceptibility. Specifically, it quantifies how oxidative aging affects the asphalt binder’s ability to resist cracking. A high Glover-Rowe Index value indicates increased stiffness and a higher likelihood of cracking.
Unaged Virgin Asphalt (Orange Line): Used as a baseline for flexibility and minimal oxidation.
PAV-Aged & Delta Mist-Treated Asphalt: Samples were treated with Delta Mist HR and subjected to aging conditions. Pressure Aging Vessel (PAV) testing at 305 PSI and 212°F simulated 7–10 years of oxidative damage.
Conclusions: Delta Mist-treated aged asphalt consistently demonstrated lower stiffness (lower Glover-Rowe Index) compared to unaged untreated asphalt.
At 50°F (critical for cracking susceptibility), the Delta Mist-treated sample was 8 times better than untreated asphalt, showcasing rejuvenation and flexibility.

Application
- Asphalt pavement must be clean and dry with a surface temperature of 50°F minimum and rising
- Applies by conventional distributors at application rates of 0.05 gallons per square yard to 0.135 gallons per square yard based on pavement condition
- Does not require heat or agitation to apply
- Does not require sand or aggregate cover and the subsequent clean-up
- Does not obscure traffic markings or affect reflectivity
- Does not negatively impact surface friction characteristics
- Does not require special handling as Delta Mist is a non-toxic, non-hazardous and non-regulated chemical
- Allows for a return to traffic in 60-90 minutes based on ambient temperature and humidity level
Medicine For Your Roads: The Science Behind Rejuvenation
The Link Between Curing Alzheimers and Delta S
The Alzheimer’s drug developed by Dr. John Warner works by targeting aggregates of proteins in the brain that bind to inorganic substrates, causing damage.
A small molecule was designed to slip between the organic and inorganic phases, disaggregate the harmful aggregates, and restore functionality. This breakthrough addressed the oxidative damage causing the disease.
Dr. Warner applied the same molecular concept to asphalt preservation. Asphalt binder, like the brain proteins, undergoes oxidation over time, causing it to become brittle.
Using a molecule with two components—one that interacts with asphalt and another that binds to aggregates—Delta S reverses the oxidation process in asphalt.
This rejuvenation process restores the original properties of the asphalt binder, allowing it to regain flexibility for workability and stiffen for durability.