Some Comments On “Rolling Out the Fabric of the Road”, an article in Grading and Excavation Contractor magazine
The current issue of Grading and Excavation Contractor magazine has a cover story on the use of geosynthetics in paving operations. The author interviewed a number of different companies in the industry covering a broad range of materials and technologies.
Survey articles like this are very useful as a starting point if you’re looking for solutions on a project. There is always a danger, however, that a high level discussion like this can leave some mistaken impressions and incomplete answers on the finer points of these technologies. The following comments are offered as precautions as you read the article:
- Woven geotextiles and geogrids should not be grouped together – they are different technologies and they perform different functions. Both can add significant value to road construction in the right circumstances, but it is critical to understand how they work and what their functions are.
- There is no correlation between tensile strength and performance in a roadway stabilization application for geogrids. None. Period. The only proven way to quantify geogrid performance in roadway applications is full-scale testing and monitoring of actual installed sections. In other words, performance data. Lots of it. Anyone who states that the performance of a geogrid can be precisely determined simply by measuring material properties is at best mistaken.
- Separation of fine-grained subgrade soils from aggregate base is a critical function, especially when the subgrade is soft or wet. Separation is accomplished at the subgrade-aggregate interface. Separation doesn’t make the pavement section stronger, but it helps maintain the strength of the section over time.
- Drainage is critical to pavement performance. It is critical that engineers and contractors fully understand how water will be managed in and around the road. Getting water out of the pavement section and away from the road as efficiently and effectively as possible has huge benefits for the road’s long term performance.
Here’s the link to the article:
http://bit.ly/MUhKqh. For full disclosure, I’m quoted at length regarding Tensar’s technologies, but I wanted to offer some additional and objective commentary to make sure those researching this topic get all the pieces of information they need.
As always, I look forward to your feedback.