Two new standards from the Geosynthetics committee of ASTM will help define properties that can be used in the design of geosynthetic reinforced pavement. I know in my practice in Arizona, ADOT simply allows a boost of Resilient Modulus (R-Value) of 10 when biaxial geogrids are used. Perhaps in time this will lead to a design method to account for the geosynthetic reinforcement in a more analytical way. [Source: Geosynthetics Magazine]
Standards and Codes
ASTM Updates September 2010
Last month there were several updates to standards involving texting the flexural strength of concrete as well as updates to some masonry and dimension stone standards. ASTM D6926 – Standard Practice for Preparation of Bituminous Specimens Using Marshall Apparatus has been updated, so if you are involved in asphalt pavement testing, make sure you go and find out what the changes are. There are also a whole slew of groundwater and site investigation standards that were reapproved.
Available Resources
ASTM Updates – 5/7/07
GeoPrac.net continues to try to keep everyone up to date on new changes to ASTM standards in soil, rock, construction and related areas. Read on for a list of newly approved standards as well as new work items.
Failures
Whales in Geomembranes: Stronger than Concrete
Geosynthetica has some interesting photos of so called ‘whales’ in geomembranes. These giant bubbles are caused by a variety of things, but are essentially gas trapped underneath the geomembrane that can have significant buoyant force, […]