30 June 2001
The percentage of loss shall not exceed 50 when tested in accordance with ASTM C-131. The material
shall also meet the requirements listed in CEGS 02722 for flat and elongated particles, liquid limit and
plasticity index, and magnesium sulfate soundness when tested in accordance with ASTM C 88. The
gradation requirements are the same as for the 100 CBR material, but fractured faces relaxed to
c. Blast Furnace Slag. Slag is a by-product of steel manufacturing. It is air cooled, crushed, and
graded to produce a dense mix. Fines from other sources may be used for blending. Requirements for a
graded crushed aggregate apply. Only blast furnace slag will be used. Minimum required unit weight of
slag is 1,200 kg/m3 (75 lb/ft3).
d. Shell Sand. Shell sand consists of oyster and clam shells that have been crushed, screened,
and blended with sand filler. Ratio of the blend shall be not less than 67 percent shell to 33 percent
sand. Refer to local specifications where available.
e. Coral. Coral consists of hard cemented deposits of skeletal origin. Coralline limestone
quarried from inland deposits and designated quarry coral is the most structurally sound of the various
coral materials available. Other types useful for base materials are reef coral and bank run coral.
Quarry coral is crushed and graded to a dense mix. The following gradation is recommended:
4.75-mm (No. 4)
0.425-mm (No. 40)
0.075-mm (No. 200)
The percentage of wear (ASTM C-131) is not to exceed 50.
Limerock. Limerock is a fossiliferous limestone of the oolitic type generally located in Florida.
g. Shell Rock. Shell rock or marine limestone are deposits of hard cemented shells located in
North Carolina and South Carolina. Refer to local guide specifications where available. Percentage of
loss should not exceed 50 when tested in accordance with ASTM C-131..
h. Stabilized Materials. Stabilized materials consist of granular materials that have been improved
by the addition of cement, lime, bitumen, or a combination of those additives with flyash. See Chapter 9
for a discussion of stabilization.
i. Crushed Recycled Concrete. Crushed recycled concrete shall consist of previously hardened
portland cement concrete or other concrete containing pozzolanic binder material. The recycled material
shall be free of all reinforcing steel, bituminous concrete surfacing, and any other foreign material and
shall be crushed and processed to meet the required gradations for coarse aggregate. Crushed