TM 5-822-7/AFM 88-6, Chap. 8
be identified by the contracting officer, and suitable
(b) Other pavements. For other pavements,
limits will be specified and materials defined when
the limiting amounts of deleterious substances in
necessary.
each size of coarse aggregate will be specified as
shown in table 5. Other deleterious substances will
Table 5. Deleterious materials in coarse aggregates for other pavements
Percentage
by
Weight
Material
2.0
C l a y lumps and friable particles
1.0
a
M a t e r i a l finer than No. 200 sieve
1.0
Lightweight
particles
2.0
Other
soft
particles
T h e total of all deleterious substances shall not exceed
Note:
5 . 0 percent of the weight of the aggregate. The percentage
o f material finer than No. 2 0 0 sieve shall not be included
in this total.
a
L i m i t f o r material finer than No. 200 sieve will be increased to
1 . 5 percent for crushed aggregates consisting of crusher dust that
i s essentially free from clay or shale.
b
This
T h e separation medium shall have a specific gravity of 2.0.
l i m i t does not apply to coarse aggregate manufactured from blast-
f u r n a c e slag unless contamination is evident.
workability and quality of the concrete. Shape will
(4.) Slag aggregate. Iron ore blast-furnace slag
be determined in accordance with CRD-C 120.
aggregates vary widely in properties depending on
the manufacturing and cooling processes used. Un-
(2.) Grading, uniformity of grading, and
aged blast-furnace slag may contain free lime, but
deleterious substances. The grading and uniformity
aging reduces this to acceptable levels. Properly aged
of grading specified in table 6 for fine aggregate are
iron ore blast- furnace aggregate has a good history
desirable for pavement concrete and can generally
of performance. Slag from steel mills, however, is
be met at a reasonable cost within the continental
not acceptable as concrete aggregate because of the
United States. However, if conformance with these
various oxides it contains.
requirements will result in undue construction costs
and if investigation of the available sources of fine
f. Fine Aggregate.
aggregate in the locality indicates that limits other
than specified are desirable, a request will be sub-
(l.) Composition and shape. Requirements for
mitted to HQDA (DAEN-ECE-G) giving complete
composition and particle shape of fine aggregate are
results of all tests conducted to substantiate that
purely descriptive, for example, natural and/or
concrete of comparable workability, durability, and
manufactured sand, spherical or cubical, and no
strength can be produced without an increase in
limits are shown. A limit will be included for flat and
cement content. The amount of deleterious
elongated particles in fine aggregate, comparable
substances in the fine aggregate shall not exceed the
with the limit specified for coarse aggregate, when
limits shown in table 7.
tests indicate that poor particle shape will affect the
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