In order to maintain the gravel roads in our town highway system, the Norwich Public Works Department performs grading operations during the spring and summer months. This is done to keep the traveled surface of the road free of ruts and potholes and to maintain a “crown” on the road surface for positive water flow during rain storms.
After grading operations are performed, it is necessary, especially in dry conditions, to apply a product for fines retention and dust control. This prevents loss of road surface and provides a dust-free traveling surface.
Since 2009, we have used a product called Safe-Bind for road stabilization and dust control. Safe-Bind is a high performance blend of ammonium lignin sulfonate and calcium or sodium chloride brines.
Lignins have been used for many years on road surfaces. Consequently, lignin manufacturers have performed extensive studies to test its impact on the environment. Results show that lignins are safe for the environment and not harmful to plants, animals, and aquatic life when properly manufactured and applied. Lignin is a naturally occurring substance in woody plants.
Lignosulfonate is a by-product of the paper-making process. It has been used as a treatment of dirt roads in Europe and North America since the 1920’s. Lignosulfonates have a natural adhesive property when moist. When applied to gravel roads, the lignosulfonate solution coats individual road particles with a thin adhesive-like film that binds particles together. It acts as a dispersant, allowing the particles to pack closer together for a stronger surface. Therefore, water uptake by the road bed surface is greatly reduced and the binder is less likely to be washed away by rain.
Environmentally Friendly Benefits of Safe-Bind
- Greater than 50% reduction in chloride ions introduced into the natural and built environment.
- Significantly less corrosive than CaCl2 or MgCI2 brines, less corrosive than water.
- Safe to handle
- Binds roads together with “Nature’s own glue”
- Cost competitive with liquid calcium chloride
Other Benefits of Safe Bind
- Creates a denser, firmer road cap. Eliminates the sliding hazards of loose dirt and gravel by binding it to a hard, skid-resistant surface.
- Improves safety by controlling dust clouds. Visibility on dirt roads is significantly increased.
- Reduces road repairs. Hardened road surfaces are less likely to suffer the ribbed, “washboard” effect common with untreated gravel or dirt roads. As a result, frequent grading can be reduced.
In conclusion, Safe Bind is the most cost effective, environmentally-friendly product that we have found to use on our roads to date. It is a green product. The only downside we have found to this product is the smell, which is evident for a short time after application. Some residents have described it as a “molasses smell”. Others describe the smell as more like burnt coffee. This smell dissipates after eight to twelve hours. It should be kept in mind that it is non-toxic to humans, animals, or plants and will not irritate dog’s feet the way calcium chloride does.