be free of materials having undesirable magnetic properties, including
magnetite in granite, high-iron minerals in traprcok, and pyrite in
limestone.] Irrespective of the source from which it is obtained, all fine
aggregate shall be composed of clean, hard, durable particles meeting the
requirements of ASTM C 33. Each type of fine aggregate shall be stockpiled
and batched separately. Particles of the fine aggregate shall be generally
spherical or cubical in shape.
2.2.3.2
Grading
Grading of the fine aggregate, as delivered to the mixer, shall conform to
the requirements of ASTM C 33 and shall have a fineness modulus of not less
than 2.50 nor more than 3.00.
2.2.3.3
Deleterious Material
The amount of deleterious material in the fine aggregate shall not exceed
the following limits by mass:
Material
Percentage by Mass
__________
___________________
Clay lumps and friable particles ASTM C 142
1.0
Material finer than 0.075 mm (No. 200 sieve) ASTM C 117
3.0
Lightweight particles ASTM C 123 using a medium
0.5
with a density of 2.0 Mg/cubic meter (Sp. Gr. of 2.0))
Total of all above
3.0
2.3
CHEMICAL ADMIXTURES
2.3.1
General Requirements
Chemical admixtures may only be used when the specific admixture type and
manufacturer is the same material used in the mixture proportioning
studies. The air-entraining admixture shall conform to ASTM C 260. An
accelerator conforming to ASTM C 494/C 494M, Type C, may be used only when
specified in paragraph: SPECIFIED CONCRETE STRENGTH AND OTHER PROPERTIES
and shall not be used to reduce the amount of cementitious material used.
Calcium chloride and admixtures containing calcium chloride shall not be
used. Retarding or water-reducing admixture shall meet the requirements of
ASTM C 494/C 494M, Type A, B, or D, except that the 6-month and 1-year
compressive strength tests are waived. ASTM C 494/C 494M, Type F and G
high range water reducing admixtures and ASTM C 1017/C 1017M flowable
admixtures shall not be used.
2.3.2
Lithium Nitrate
**************************************************************************
NOTE: Contact the TSCMX, Navy EFD, NFESC, or AFCESA
before specifying Lithium Nitrate to mitigate
Aggregate-Silica Reaction (ASR). Coordinate with
manufacturer regarding Lithium Nitrate dosage.
**************************************************************************
The lithium admixture shall be a nominal 30 percent aqueous solution of
Lithium Nitrate, with a density of 1.2 kilograms per liter 10 pounds per
SECTION 02753
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