Unpaved Road Design and Tough Cell® Performance
It is estimated that 80% of the world’s roadways are unpaved – millions of miles of transportation corridors coping with traffic and climate without the protection of pavement. Bringing modern geotechnical engineering to unpaved road design can add significant durability to any secondary road anywhere in the world.
What’s at Stake
Unlike paved surfaces, gravel roads have a porous wear layer and must maintain a “crown” to prevent water accumulation and erosion. The chief cause of the crown flattening out is a poor base support structure.
Low quality roads require an inordinate amount of material recovery, reshaping and/or amending to ensure intrinsic damage doesn’t occur, all in a continuous effort to avoid:
All of these can take their toll on vehicles and motorists.
Current gravel road design practices
The challenge for a road building company and for currently practiced unpaved road design is to construct a strong subbase and base for the road’s wearing course. Strength below translates to long life for the road as a whole. Creating that strength has been hit and miss using conventional technologies.
Paradox with Tough Cell, however, routinely builds-in that needed strength and increases the durability of gravel roads with geocell soil stabilization technology.
Better Roads for the Long Term
When a road subbase and/or base is built with Tough Cell, the modulus of the construction material is greatly increased resulting in significantly improved overall strength in the road structure.
The Tough Cell aggregate confinement of the subbase:
- Gives solid support to the wear layer
- Creates a beam effect of weight distribution
- Restricts road creep
- Cuts material attrition
These qualities together provide near ideal conditions for a long-lasting, low-maintenance gravel road.
Secondary Roads with First Rate Construction
An unpaved road design which includes Tough Cell saves money not only with its reduced maintenance schedule over the long haul but also with initial construction at the outset.
Here’s how. Tough Cell:
- Requires less materials overall
- Improves modulus enough to reduce the road thickness while increasing support.
- Uses lower cost inferior infills
- Works well with weaker granular materials like sand, river rock and RAP.
- Compatible with local material supplies
- Keeps transportation costs down.
- Means faster construction – Tough Cell installs quickly but more importantly, the increased modulus means fewer layers (lifts) are required. This leads to:
- Reduced transportation
- Reduced placement
- Reduced compaction
Savings on initial construction is generally 10% at a minimum and often much more. The savings compound with reduced maintenance over the years to come.
Geotechnical Engineering Approach
Paradox Access, with its pedigree of industrial and access road construction services, respects the role that our rural roads and highways play. It’s with that respect that Paradox brings cellular confinement technology and modern geotechnical engineering to a secondary road near you.
Quality unpaved road design is going be needed for the generations ahead. Tough Cell is going to be leading the way.