Geotextiles are frequently used for subgrade improvement under roadways. Caltrans has released a document titled "Guide for Designing Subgrade Enhancing Geotextiles". This 18-page document covers what situations can be improved using geotextiles and includes a flowchart for guidance on when to apply them and for what purposes. From Geosynthetics magazine. (Image by Caltrans)
April 7-11 is National Workzone Awareness Week (NWZAW) which draws attention to the hazards roadway construction crews face from motorists not heeding safety warnings. For 2006â€”the last year for which data is availableâ€”more than 1,000 died in work zones. Figures for 2007 will be released by the National Work Zone Safety Information Clearinghouse later this year. Motorists are also at risk for not following work zone safety precautions. They may face damage to their vehicles, injuries, and loss of life. For 2006, 614 motorists died in work zone crashes. (Graphic by Caltrans)
Below are a few items to think about the next time youâ€™re driving through a workzone taken from a Caltrans fact sheet. More after the break (sorry for the â€œDuhâ€ ones, but I didnâ€™t write them). As someone who occasionally works on the road and knows many more people who do, please, please remember to slow down!
- Most injuries and deaths in the Cone Zone are from rear-end collisions.
- If you slow from 65 to 55 mph for one mile, you only lose 10 seconds on your travel time.
- The first cause of death for people aged 16 to 20 is car crashes. Even if you don’t lose your life causing a car crash, it could still cost you your license or a heavy fine.
- If a car’s speed is doubled, the stopping distance is doubled twice over. For example, if a car traveling at 30 mph requires 100 feet to stop, the same car at 60 mph takes not 200 but 400 feet to stop.
- At 60 mph, you’re traveling 88 feet per second. A lot can happen in one second, so give yourself plenty of room to stop in case of an emergency.
- For the 15,000 miles of California highway Caltrans maintains, it must buy 120,000 new cones every year to replace ones run over by careless drivers.
Standards governing the testing of tensile strength of geogrid and geotextile tensile strength are among the standards updated over the past month by the ASTM. This includes a new standard for "Determining Small-Strain Tensile Properties of Geogrids and Geotextiles by In-Air Cyclic Tension Tests". A number of standards relating to concrete including capping of concrete cyllinders for testing have also been updated. Click through for the list.