2.1.4
Pozzolan (Fly Ash)
Pozzolan shall conform to ASTM C 618, Class C or F, including low alkali
[multiple factor,] [drying shrinkage,] [uniformity,] [,and [moderate]
[severe] sulfate resistance] requirements in Table 3 of ASTM C 618.
[Requirement for maximum alkalies from Table 1A of ASTM C 618 shall apply].
If pozzolan is used, it shall never be less than 15 percent nor more than
35 percent by weight of the total cementitious material. The Contractor
shall comply with EPA requirements in accordance with Section 01670
RECYCLED / RECOVERED MATERIALS.
2.1.5
Ground Granulated Blast-Furnace (GGBF) Slag
ASTM C 989, Grade 120.
2.1.6
Silica Fume
**************************************************************************
NOTE: Silica Fume Concrete should be used where low
permeability and enhanced durability are necessary
and justified by additional cost, such as marine
structures, other places where low permeability is
needed, and severe abrasion resistance. Finishing
is more difficult than conventional concrete.
Proper curing is essential because there is a strong
tendency for severe plastic shrinkage cracking.
Supervision by manufacturer's representative should
be required during batching, finishing, and curing
at start-up of the job. A HRWR recommended by the
manufacturer of the silica fume should be used.
**************************************************************************
Silica fume shall conform to ASTM C 1240. Available alkalies shall conform
to the optimal limit given in Table 2 of ASTM C 1240. Silica fume may be
furnished as a dry, densified material or as a slurry. In accordance with
paragraph Technical Service for Specialized Concrete, the Contractor shall
provide at no cost to the Government the services of a manufacturer's
technical representative experienced in mixing, proportioning, placement
procedures, and curing of concrete containing silica fume.
2.2
AGGREGATES
**************************************************************************
NOTE: Edit and fill in the blanks as appropriate.
Consideration should always be given to the local
aggregate supply situation, quality, and
availability.
**************************************************************************
Aggregates shall conform to the following.
2.2.1
Fine Aggregate
Fine aggregate shall conform to the quality and gradation requirements of
ASTM C 33.
SECTION 03300A
Page 26
Previous Page
