ETL 1110-3-503
15 Sept 99
Texas, Arkansas, and Alabama (Collins and Ciesielski 1994). There has been very
limited research with these wastes and currently there is no known use for them in
pavement construction.
g. Waste rock . Waste rock is rock removed during mining operations that has little
or no mineral value. The amount of waste generated varies with the type of mining
operation, although the greatest amounts usually occur at surface (open pit) mining
operations (Collins and Miller 1976). The quality of the rock can vary widely with the
location of the mine and to the extent that impurities are present. It is estimated that
approximately 1 billion tons of waste rock and overburden are generated each year
(Collins and Ciesielski 1994). Due to the nature of the mining operations, the wastes are
generally located in remote areas far from where they are needed for construction. Lim-
ited use of this waste has been reported, mainly due to the remote locations and the
availability of other suitable construction aggregates. New York State reports
satisfactory results with using waste rock as fill for embankments and riprap for drainage
uses (Collins and Ciesielski 1994).
B-6. Available Specifications
a. Specifications are generally not available, except for a few waste materials that
have had extended usage. Specifications exist for reclaimed asphalt pavement, scrap
tires, iron and steel slags, reclaimed concrete pavement, fly ash, and plastic waste. These
materials have been widely used; at least in areas of the country that produce the par-
ticular waste material. Some type of local specification probably exists for other waste
materials that have been used in construction of a pavement. Construction specifications
for the use of materials such as foundry sands for fills will be basically the same as those
used for typical granular backfill materials. These specifications provide requirements
for lift thickness and compaction requirements (Abichou et al. 1998).
b. One requirement for satisfactory specifications is the development or availability
of suitable test and evaluation methods. One study provided recommendations for testing
and construction using tire chips (Edil and Bosscher 1994). In many instances test
methods suitable for use in design and construction specifications have been developed;
however, they are often not standardized for ready usage in standard specifications.
c. The CE has a guide specification that covers the use of reclaimed asphalt
pavement in hot-mix asphalt (CEGS 02749). There are two manuals (TI 822-08 and TM
5-822-7) which address the use of reclaimed asphalt pavement, iron and steel slags,
reclaimed concrete pavement, and fly ash. The CRD-C and ASTM standards that pertain
to the classification and use of fly ash are listed below:
(1) CRD-C 255 & ASTM C 618 - Standard Specification for Coal Fly Ash and
Raw or Calcined Natural Pozzolan for Use as a Mineral Admixture in Concrete
B-20
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