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Bituminous Products   These products include asphalt cutbacks,

a~.phalt emulsions, and road tars.  Bituminous products act as

adhesives in the soil mass    They will prevent dust as long as

wheel and track ruts do not break through the treated layer.

Bituminous materials may be applied as a penetration treatment or

as an admixture    For a penetration treatment to be effective the

soil must be sufficiently free of fines.   to allow adequate depth

of penetration.   In extreme fine qrained soils as in Saudi

~rabia, penetration treatments ~rcduce a thin crust of bituminal

soil which will  be effective only as a nontraffic area.   In an

admixture application the soil  is scarified and bituminous

product is sprayed into the soil    ~fter mixing by windrowing,

harrowing, or rototilling the treat soil is shaped with a motor

grader    Compaction with a rubber tired or sheepsfoot roller

completes the treatment.   The admixture method strengthens the

soil as well as acting as a dust palliative.    In choosing between

a bituminous penetration treatment and an admixture we must

consider the realities of the operational environment.    Soldiers

have a tendency to drive on anything that looks black     Even if

an area is designated as nontraffic and treated with a

penetration application, vehicles will use the area unless

positive steps are taken to restrict traffic    Bituminous

products are the cheapest form of dust control costing about

$1.8~ per square meter for an admixture.    In Saudi 4rabia asphalt

emulsions are performing extremely well,   however, extreme caution

should be used with mix water.    Commercial premixed emulsions are

safe but local addition of brackish emulsion water could cause

premature breaking and ruin distributors.

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