Waste

Proctor Normal

Modified Proctor

CBR

Use in road construction

Wopt

(%)

Ρd opt

(kN/m³)

Wopt

(%)

Ρd opt

(kN/m³)

CBR 4i%

IBI

%

Coal mine waste rock [18]

11.2

19

10.11

20.4

9

29

Sub-base layer

Phosphate mine waste rock [16]

12.9 - 14.60

17.9

-

-

13

-

Sub-base layer and backfill