adverse effects of deleterious materials.
2.2.3
Aggregates
ASTM C 33, except as modified herein.
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NOTE: The quantities to be retained on each sieve
may be adjusted only where available aggregates are
mix mobility, or available aggregate gradations do
not comply with the 18-8 requirement. When
necessary to satisfy local conditions and when
permitted, the combined aggregate percentages may be
changed to not more than 22 percent nor less than 6
percent retained on any individual sieve.
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a.
The combined aggregates in the mixture (coarse, fine, and blending
sizes) shall be well graded from the coarsest to the finest with
not more than 18 percent nor less than 8 percent, unless otherwise
permitted, of the combined aggregate retained on any individual
sieve with the exceptions that the 300 micrometers No. 50 may have
less than 8 percent retained, sieves finer than 300 micrometers
No. 50 shall have less than 8 percent retained, and the coarsest
sieve may have less than 8 percent retained. Use blending sizes
where necessary, to provide a well graded combined aggregate.
Reports of individual aggregates shall include standard concrete
aggregate sieve sizes including 37.5 mm 1 1/2 inches, 25.0 mm one
inch, 19.0 mm 3/4 inch, 12.5 mm 1/2 inch, 9.5 mm 3/8 inch, 4.75 mm
No. 4, 2.36 mm No. 8, 1.18 mm No. 16, 600 micrometers No. 30, 300
micrometers No. 50, and 150 micrometers No. 100.
b.
Provide aggregates for exposed concrete from one source, ASTM C 227.
Do not provide aggregates that react deleteriously with alkalies
in cement. Refer to appendix, paragraph entitled "Test Method
C227" of ASTM C 33 for expansion limits. Provide aggregate
containing no deleterious material properties as identified by
ASTM C 295.
c.
Where a size designation is indicated, that designation indicates
the nominal maximum size of the coarse aggregate.
d.
Aggregate may contain materials deleteriously reactive with
alkalies in the cement, if cement contains less than 0.60 percent
alkalies (percent Na2O plus .658 percent K2O). Provide a material
such as fly ash, slag, or silica fume as specified to be effective
in preventing harmful expansion due to alkali-aggregate reaction
by ASTM C 441.
e.
Where historical data is used, provide aggregates from the same
sources having the same size ranges as those used in the concrete
represented by historical data.
f.
Marine aggregate may be used when conforming to ASTM C 33 and if
it originates from the up-current side of the land mass and it has
been washed by the fresh water so that the total chloride and
sulfate content of the concrete mixture does not exceed the limits
SECTION 03311
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