Benefits of Geosynthetics for Stabilizing Unpaved Roads
Throughout history, roads have been built to connect people, communities, and cultures around the world. From the Silk Road and the Grand Trunk Road to the famous flagstone roads that helped to fuel the Roman Empire’s rise to power in ancient times, roads have been a critical component of the world’s evolution. The earliest known road dates back to 4000 BC, in what was then known as Mesopotamia. While some early roads were paved with stone or brick held in place with bitumen, most were unpaved. Stabilizing these roads took great ingenuity since early road builders lacked the many benefits of geosynthetics that stabilize today’s roads. They relied on a variety of organic materials for stabilization including timbers, palm fronds, and various plant fibers.
Currently, over 1.4 million unpaved roads exist in the United States, almost 35% of the nation’s roadways. As in ancient times, these unpaved roads are an essential component of human development and interconnectivity. They connect us to rural areas and work sites throughout the country. Whether temporary or intended for long-term use, it is critical to stabilizing these unpaved roads for safe travel. Today’s road builders rely on geosynthetics to ensure their stability.
Benefits of Geosynthetics
When building unpaved roads on soft subsoil, the biggest concerns are rutting and intermixing of aggregate base material into the subsoil. For the smaller geosynthetic strains and rutting depths associated with both paved and unpaved roads, road base stabilization is implemented. With the larger geosynthetic strains and rutting depths consistent with unpaved roads, stabilization of the subgrade soil is necessary. The appropriate geosynthetic is normally placed between the road base and the underlying subgrade. The requirements of the project will dictate the type and specifications of the geosynthetic needed.
Geotextiles and geogrids are the primary geosynthetics used in unpaved roads. Geotextiles are synthetic fibers that are bonded or woven to create a flexible, porous fabric with a strong resistance to biodegradation. They prevent the base material from mixing with the subgrade soil, providing separation between the two materials and maintaining the integrity of each.
Made from a variety of polymer materials, geogrids are either woven together, heat welded, or produced by punching a consistent pattern of holes in sheets of material. They provide reinforcement of the base material while increasing bearing capacity. This results in the transfer of horizontal force and reduced rutting.
In some cases, geocells are also used in the construction of unpaved roads. This type of geosynthetic consists of a series of interconnected individual cells made from polymers. The geocells are expanded at the construction site and filled with soil. The cell walls completely encase the soil, providing complete confinement while increasing reinforcement. Geocomposites can also be used in the construction of unpaved roads. A combination of two or more geosynthetics, geocomposites are ideal for filtration and drainage.
The benefits of geosynthetics in the construction of unpaved roads include improving the design, controlling evaporation, reducing erosion and enhancing longevity and safety. Equally important, geosynthetics help protect the environment by conserving energy and the earth’s resources. The use of geosynthetics can also reduce the thickness of the base material, minimizing construction costs.
Choosing the Right Geosynthetics
Ultimately, the benefits of geosynthetics in roadway construction can increase performance, extend service life and save money. IWT Cargo-Guard offers many types of geosynthetics and understands that choosing the proper geosynthetic for your application can be challenging.
Our mission is to assist our clients in winning business by providing the most cost-effective products for your job site. By quickly analyzing the products and services you need for your project, we become an extension of your estimating department. At IWT Cargo-Guard, we have the knowledge and experience to help you choose exactly what you need. Contact us today.