Aggregate - Recommended Gradations:
Type II Production
Screen Size % Passing Tolerance
3/8” 100 +7.0/+7.0
#4 90-100 + 7.0
#8 65-90 +40
#16 45-70 +40
#30 30-50 +40
#50 18-30 +40
#100 10-21 +40
#200 5-15 +2.0
Suggested Application Rates:
Type II - Urban and Residential Streets and Airport Runways:
single course = 18-20 lbs//s.y.
double course = 28-32 Ibs./s.y.
Note: all application rates above are dry aggregate weights exclusive of emulsion and all other
additives.
D. EQUIPMENT
General
All equipment, tools, and machines used in the performance of this work shall be maintained in
satisfactory working condition at all times to ensure a high quality product.
Mixing Equipment
The material shall be mixed by a self-propelled micro-surfacing mixing machine which shall be a
continuous flow, continuous run mixing unit able to accurately deliver and proportion the
aggregate, emulsified asphalt, mineral and field control additives, and water to a revolving multi-
blade twin shafted mixer, and discharge the mixed product on a continuous flow basis. The
contractor shall own and have available two (2) continuous flow, continuous run mixing
machines to ensure highest quality, and to mitigate the effect of equipment breakdowns. The
machines shall have sufficient storage capacity for aggregate, emulsified asphalt, mineral and
field control additives, and water to maintain an adequate supply to the proportioning controls.
The machines shall be equipped with self-loading devices which provide for the loading of
materials while continuing to lay micro-surfacing, thereby minimizing construction joints.
Proportioning Devices
Individual volume or weight controls for proportioning each material to be added to the mix, 1.e.,
aggregate, emulsified asphalt, mineral and field control additives, and water shall be provided
and properly marked. These proportioning devices are usually revolution counters or similar
devices, and are used in material calibration and determining the materials output at any time.
