Enhanced Design Materials for Better Roadways

by Bryan Gee, P.E., on September 08, 2018

How geosynthetic materials protect pavement integrity and extend pavement life by as much as 500%?

Why don’t my pavements hold up like they used to? With growing urban populations, increasing truck traffic, volatile materials costs and mounting pressure from owners to deliver better roadways quicker and cheaper, engineers are scratching their heads.

Tensar TriAx Geogrid Pavement Optimization for Roadway Life ExtensionUnfortunately, it’s no longer sufficient to simply specify a standard pavement section or perform a basic design. Increasing costs for asphalt and crushed aggregate make it prohibitively expensive to build pavements strong enough to carry the extreme loads that are now required. And once the underlying structure of pavements start to deteriorate, no maintenance budget is sufficient to keep up. To quote the National Association of County Engineers, “roads wear out from the top down, but they fall apart from the bottom up.”

But advanced engineering technology can bridge the gap between conventional practice and improved pavement performance. To accommodate increasing traffic loads without incurring distress to the pavement structure over time, engineers are implementing enhanced design to build better roads from the ground up – with the help of geosynthetic materials.

Enhanced design incorporates materials and a design approach that meet current and projected traffic capacity in the most cost-effective and reliable method possible. Engineers tailor design parameters for specific site conditions and projected traffic capacities relative to material availability, project budget and life cycle costs, to deliver improved outcomes for their clients.

State-of-the-art geosynthetics help build more robust pavement sections by using aggregate base and subbase materials more efficiently. Geosynthetic materials like Tensar’s TriAx Geogrid are solving owner problems by creating mechanically stabilized pavement structures with improved ability to carry traffic loads, increasing pavement life. TriAx Geogrid is used in the granular subbase and aggregate base layers to provide stiffness enhancement and prevent lateral displacement, which maintains the pavement’s structural capacity. When used in a mechanically-stabilized layer of flexible pavement, these materials deliver an improved level of performance – extending pavement life by as much as 500%.

In cases where budgets are severely constrained, engineers have used these benefits to reduce overall pavement thickness – including the asphalt, aggregate base and granular subbase – by as much as 50% while maintaining traffic capacity.

Over 25 years of research, including studies by the FHWA, AASHTO, the United States Army Corps of Engineers and multiple universities, have proven the benefits of geosynthetic materials in improving pavement structures and prolonging pavement life.

Across the country, engineers are implementing enhanced design to create flexible pavement systems with less materials, lower construction costs, expedited schedules and longer lifespans. With the advancement of geogrid stabilization products, owners are saving time and money in the management of infrastructure assets – and engineers are building better roadways.


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