(CSS-1h) is preferable to the anionic (SS-1h) for
use as fog seal. Cationic emulsion will cure at a
faster rate than anionic and is more suitable where
high humidity prevails. Anionic emulsions possess a
negative charge on the asphalt droplets and cationic
emulsions carry a positive charge on the asphalt
droplets. All aggregate possess a negative surface
charge at their natural pH. This negative surface
charge varies in intensity depending on the
geological source of the aggregate.
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Emulsified asphalt for Fog Seal shall conform to ASTM D 977, [SS-1] [SS-1h]
[_____] for anionic and ASTM D 2397[CSS-1] [CSS-1h] [_____] for cationic
materials.
2.5
WATER
Water shall be fresh, clean, and potable.
PART 3
EXECUTION
3.1
PREPARATION OF SURFACE
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NOTE: If the surface to be treated requires
repairs, the method of repairs and extent of work
involved should be shown or described.
Removal of paint and rubber deposits are generally
accomplished by high pressure water blasting. Few
approved chemicals are effective and sandblasting is
not permitted by air pollution regulations at some
locations. Mechanical abrasion generally causes
damage to the pavement.
Bracketed sentence at the end of this paragraph
applies to Fog Seal; remove when not used in the
project.
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Damaged surface shall be repaired and cracks filled before starting work.
Immediately before starting work, all loose material, dirt, clay, or other
objectionable material shall be removed from the surface to be treated with
power brooms or power blowers, if needed. Paint firmly bonded to the
surface that has the chalk removed may remain. Material removed from the
surface shall not be mixed with the cover aggregate.[ When necessary to
achieve a clean surface for fog application, flushing with water will be
permitted.]
3.2
SEAL COAT APPLICATION
3.2.1
Rate
The bituminous material shall be spread in the quantities shown in TABLE
III. The exact quantities within the range specified, which may be varied
to suit field conditions, will be determined by the Contractor and approved
by the Contracting Officer prior to use.
SECTION 02785
Page 15
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