Hi I did a standard proctor and got

[Stark85]

Hi I did a standard proctor and got my dry density and moisture content for 5 separate samples for my curve. How do I determine the max dry density(PCF) value that will be put in the nuclear gauge?

 

[Eric C.]

Plot the points with the moisture content on the X axis and the dry density on the Y axis then draw your curve. The high point of the curve is your maximum dry density. Go straight down to the X axis from the high point of the curve and read your corresponding optimum moisture content.

 

[Stark85]

Right but then what do I input into the nuclear gauge? My optimum dd and mc is 1.98/13.2%

 

[Eric C.]

1.98 PCF? Something seems off with that number. Depending on the type of soil you have that number may have a wide range but more in the 90 to 120 +- PCF area.

 

[BigH]

ALso, I draw your attention to the fact that the nuclear gauge moisture content determination during the test is highly unreliable and on the high side. This was noted in Toronto years ago when the lab moisture was 70% of the nuclear gauge. Also USBR EM 1110-2-1911 and USBR DS13-10 both clearly point this out. You may want to confirm lab moisture to nuclear moisture to get a site specific calibration.