Proctor test

[killswitchengage]

Hi
why is it necessary to use 5 points in the proctor test , if 3 points can help you to find the optimum quiet easily

 

[Ron]

In some soil types, there is a "double peak" in the curve, with one peak lower than the "real" one.

Four points should be adequate to define a curve.

 

[dik]

With non-cohesive soils, it's often better to have more than 4. Proctor tests on these soils can be a bit erratic.

Dik

 

[geomane]

FDOT now requires 5 points for LBR

 

[dik]

for cohesive and non-cohesive? Clays in our environs give very consistent values.

Dik

 

[Ron]

Agree with dik that some soils require 5 points. I deal with coastal plains soils in Florida and sometimes it is necessary.

jmcc...correct for LBR....a special test relevant to Florida.

 

[killswitchengage]

So kind of you to answer
can someone provide me with an example with a double curve phenomena and which material is it

 

[killswitchengage]

Ok so Lee and Suedkamp 1972 studied the forms of proctor curve and they relate some of them to the liquid limit of the soil