r-values 1

[rock0977]

i have a Question-
Can r-values the (test done on some soil samples to determine what the thickness for the sub-grade and the asphalt thickness needed when designing new roads)variey from 40 to 68 within 200 ft distance?
thank you

 

[emmgjld]

The R-Value (Hveem-Carmany Test) varies with soil types. If the soil has changed in 200 feet, then the R-Value has most likely changed. From the values you have given, it is possible the change has been from a sand to a gravelly sand. A change in the gradation or the plasticity of the fines can result in significant changes.