CBR

Test item low-strength flexible conventional LFC1 was 20 feet shorter than the other test items, and only one trench was opened in it to characterize the strength of the subgrade. Test item LFC2 failed uniformly along its length and within each traffic path. The CBR of each traffic path of test item LFC2 was therefore characterized by opening two trenches: west and east. Trenches were not opened in LFC3.

Post-traffic trench measurements were made in the traffic paths at the surface of the subgrade, and at depths of 12 and 24 inches from the top of the subgrade. Each CBR value was calculated as the average of at least 3 measurements, with three penetrations per measurement.

The following table summarized the CBR values measured during Post Traffic Testing. More detailed data can be found in the report listed at the end.

DOT/FAA/AR-TN07/14

http://www.tc.faa.gov/its/worldpac/techrpt/artn0714.pdf