Materials (421.02)
Proportioning (421.03)
Weather Limitations (421.04)
Mixing Equipment (421.05)
Equipment Calibration (421.06)
Spreading Equipment (421.07)
Surface Preparation (421.08)
Test Strip (421.09)
Application (421.10)
Acceptance (421.11)
Materials (421.02)
Validate that the latex and CSS-1H emulsion used meets
requirements. Collect the
manufacturer’s certificate of analysis and statement of compliance for each
load.
Proportioning (421.03)
Validate the JMF approval.
Weather
Limitations (421.04)
Allow the microsurfacing to be placed if:
- minimum
surface temperature is 40° F (5°
C).
- no air
temperature below 32° F (0°
C) is forecast within 24 hours of placement.
- minimum
surface temperature is 50° F (10°
C) between September 30 and May 1.
Mixing
Equipment (421.05)
Validate the contractor is using proper equipment.
Equipment
Calibration (421.06)
Witness calibration of the mixing equipment before start or
for any design change. Obtain
documentation of individual materials calibrations from the equipment
calibrator.
Spreading
Equipment (421.07)
Validate the contractor is using proper equipment and that
it moves and spreads the material uniformly without excess loss in isolated
areas.
Surface
Preparation (421.08)
Be sure the surface is clean before application. Check for proper tack application. Be sure raised pavement markers are removed.
Test
Strip (421.09)
Be sure a test strip is constructed in the same time of day
as construction is expected. Review the
test strip after 24 hours to determine acceptability. The test strip may be only waived according to 421.09.
Application (421.10)
Check for the following construction requirements:
- no
skips, lumps, or tears in the material placed
- complete
coverage
- no
unmixed aggregate
- no
excess crown on rut fills
- restore
the crown of the designed pavement cross section
- apply
leveling at 14 pounds per square yard (7.6 kg/m2)
- apply
a surface on a microsurfacing course at 16 lbs per sq yard (8.7 kg.m2)
- apply
a surface not on a microsurfacing course at 18 lbs per sq yard (9.8 kg.m2)
- neat
seams at 1 to 6 inches where passes meet
- maintain
straight edge lines and other lines
- check
for cure before release of traffic but that it cures within 1 hour.
- stop
placement if excessive streaking or other problems develop
- Use a
rubber tire roller if the material is not under traffic within 48
hours. The roller tire should meet
401.13
and tire pressure should be 40 to 60 psi (275 to 400 kPa).
Acceptance (421.11)
Accept microsurfacing based on the Engineers summary of
quantities for each day provided the proportion of binder to dry aggregate is
maintained within 2 gallons per ton (8.5 L/metric ton).