How Geogrids Work to Keep Projects on Track
by Bryan Gee, P.E., on August 10, 2018
America’s highway system is aging, with many roadways and bridges structurally deficient or nearing the end of their design life. This is a solvable problem. Engineers have been solving transportation infrastructure problems for thousands of years – they laid the framework for roadways that expand our communities far beyond what was ever thought possible. The earliest stone paved roads have been traced to Mesopotamian engineers around 4,000 B.C. Many millennia later, the need for engineers to adopt more effective roadway design is more important than ever. The field of geosynthetics arose in the late 20th Century delivering a way to mechanically stabilize roads with greater success. These polymeric products stabilize terrain in a variety of applications to extend roadway longevity, reduce maintenance costs and improve motorist safety. Now, it seems, the multiple benefits delivered by geosynthetic materials may be an important component of solving our current transportation infrastructure dilemma.
Building a strong foundation for increased infrastructure asset lifespan
In the past, engineers have utilized conventional aggregate base to install pavement sections for new and reconstructed roadways. However, with rising construction costs and increasing traffic demand traditional methods for construction are becoming too costly and typical pavement sections are failing before their predicted design life. Today, more owners are choosing to implement geogrids to improve the performance of the aggregate within pavement structures to combat increasing material costs, increasing traffic loads and inadequate pavement structures created with traditional pavement sections.
Studies have shown that the use of geogrids under major roadways extend pavement life, reduce long term maintenance and repair and ultimately increase owner savings. As a value engineering alternative to conventional materials and practices, the engineering team at Tensar International utilizes multiple geogrid solutions for mechanical ground stabilization in a variety of infrastructure applications. One such geogrid solution, Tensar TriAx® Geogrid, is specifically designed for trafficked surfaces. Manufactured from a punched polypropylene sheet, oriented in multiple, equilateral directions to form triangular apertures, the TriAx system leverages the strength of triangular geometry to provide an enhanced level of in-plane stiffness and deliver optimal in-service stress transfer to it from the aggregate to the stabilizing geogrid. This unique geosynthetic material improves the performance of pavement materials and reduces construction time.
These geogrid products improve load distribution over weak subgrades, reduce differential settlement, and confine and lock up roadway aggregate, creating a mechanically stabilized layer for a variety of applications. They have been used in over half a million projects worldwide including major highway projects, unpaved windfarm and mining applications, foundation construction, and port and airport runways. In many cases, geogrids are used to accommodate intense loads and volumes from aircraft, mining trucks and heavy construction equipment. Geogrids create stiffened platforms that maintain the stiffness of the aggregate better over time as well as distribute loads more efficiently over subgrade soils. As a result, our infrastructure is constructed with enhanced structural integrity, greater service life, while also reducing construction time, cost and environmental impacts.
Download our handy subgrade improvement pocket card to see how using TriAx geogrid helps reduce cut/fill requirements and improve job site subgrade conditions.
Did you know our staff is also able to help evaluate conditions and provide design assistance - at no cost to you? We have assisted contractors and engineers on thousands of projects and have the expertise, research and engineering to help provide cost and time savings to your projects.