Registered Engineer/Landscape Architect must review and approve mix that is
standard with state requirements
Asphalt Installation Guideline: Hot Mix Asphalt (HMA) Construction
1.0 Scope
This guideline covers the components and methods of installation to complete the construction of a
Hot Mix Asphalt (HMA) base course and leveling/surface course for a running track and/or field
events areas. It does not cover proper sub-base construction or drainage considerations. The
success of any installation is dependent upon a properly constructed sub-base and good drainage.
Please see the appropriate ASBA guidelines for details.
2.0 Design
A. Minimum Base Course Thickness:
As recommended by a Geotechnical Engineer.
B. Minimum Recommended Leveling/Surface Course Thickness:
As recommended by a Geotechnical Engineer.
C. If the asphalt (HMA) exceeds 3” in total thickness, it should be installed in two lifts.
3.0 Quality Assurance
For installation of running track and field event HMA, utilize only thoroughly trained personnel
experienced and familiar with running track and field event paving and with the tolerances required
by the appropriate governing body.
4.0 Asphalt
The proper type of asphalt (HMA) used will vary from state to state if using the standard normal mix
designs of the local Department of Transportation (DOT) or State Highway Departments. The
following are suggested ranges for the job mix formula which if manufactured and placed correctly
should yield the best results. These are suggested ranges, but a Registered Engineer/Landscape
Architect must review and approve mix that is achievable with local aggregates.
Thickness of any layer: base course or leveling/surface should not be less than 1” compacted.
If using a Gyratory Compactor: the NDesign should be N50.
If using a Marshall Compactor: the design should be 50 blows per side.
In either method used for design, the optimum asphalt content should be picked at 3.0% air voids.
Aggregates to be used should be local aggregates and should be 100% crushed.
Limestone, gravel, quartzite, granite shall be used. At no time will steel slag or blast furnace slag be
allowed.
1" (25.0 mm)
3/4" (19.0 mm)
1/2" (12.5 mm)
3/8" (9.5 mm)
No. 4 (4.75 mm)
No. 8 (2.36 mm)
No. 16 (1.18 mm)
No.30 (600 µm )
No.50 (300 µm )
No.100 (150 µm )
No.200 (75 µm )
Asphalt content
Design voids
Base
Course
100
82-100
60-85
60-80
38-65
20-40
10-25
<50% of #4
4-15
4-9
3-6
4-7
3.0
Leveling/Surface
Course
100
90-100
60-80
35-65
20-40
20-40
10-20
6-10
4-7
4-7
3.0
*Careful attention will be made as to the dust/asphalt ratio of any mixture to be placed on the
project. High mineral filler (dust) or -#200 sieve components reduce the strength of the HMA
mixtures and will be required to be monitored by means of extraction during production of the
HMA.
5.0 Plant, Equipment, Machines and Tools
A. General
The bituminous plant should be capable of producing the quantities of bituminous mixtures
required without delays of HMA being shipped to the job site. Hauling, placing and compaction
equipment should be provided in sufficient numbers that the placement capacity at the site is
equal to or greater than the planned plant output to the site.
B. Paver
All pavements, where applicable, should be placed with a self-propelled asphalt paver. The
screed width should be adjustable to no less than eight (8) feet. Only hydraulic screed and
augur extensions to achieve width greater than the main screed are acceptable.
C. Compaction Equipment
Compaction equipment should consist of steel drum asphalt rollers of sufficient size and width
to properly compact the HMA to the required density, while providing a smooth surface free
from bumps, roller marks and creases. The use of vibratory rollers is required for initial
breakdown rolling. Steel wheel static rollers or vibratory rollers in static mode are to be used
for finish rolling of the mat.
D. Transportation Equipment
Transportation of the HMA to the site from the asphalt plant should be in trucks having tight,
clean and smooth beds lightly coated with an approved release agent. No fuel oil will be
allowed to be sprayed into truck beds as a release agent. Each load should be covered with a
canvas or other approved truck tarp of ample size to protect the mixture from cooling in transit.
E. Straightedge
The contractor should furnish and maintain at the site, in good working condition, one (1) 10’
straightedge for each paver being utilized on the project.
6.0 Placement and Compaction
A. Hot Mix Asphalt (HMA) courses should only be placed on the specified base, free from
contamination and with no free water on the surface.
B. Paving operations should not be scheduled unless there is ample time to place, compact and
finish roll the HMA.
C. Mix temperature at the paver shall not be less than State Department of Transportation
guidelines and in no case shall be lower than 225 degrees F.
D. Paving operations should provide a mat that is smooth, dense and of the proper slope and
planarity.
E. A prime or tack coat shall be placed over the base material and should be an RC-70 or similar
prior to the base course being placed, and should have ‘cracked’ before actual placement of the
HMA base course begins.
F. A prime or tack coat shall be placed over the base course HMA and should be an RC-1 or similar
prior to the leveling/surface course HMA being placed, and should have ‘cracked’ before actual
placement of the HMA leveling/surface course begins.
G. The leveling/surface course should be placed such that the longitudinal joints are offset from
that of the base course. Transverse joints should be offset a minimum of 24”.
H. In placing each succeeding pass after the initial one, the screed of the paver should be set so
that it overlaps the preceding pass by 2” and be sufficiently high so that when compacted, a
smooth joint is produced. Prior to pinching the joint, the excess material shall be pushed to the
edge of the new pass with a lute. Excess material should be removed and discarded.
I. Breakdown rolling shall begin as soon as possible after the mixture has been placed without
creating undue distress to the mat. No delays in rolling should be permitted.
1. A growth curve should be performed using an approved and calibrated nuclear density
gauge using the Gmm from the design.
2. Rolling shall continue until max density is achieved. This becomes the target density value
for the gauge.
3. A rolling pattern shall be established using the maximum field density as a target value.
4. Density requirements will then be 95-102% of that maximum field density.
After breakdown rolling has been completed, preliminary testing of grade, slope and planarity
should be done. Any deficiencies should be immediately corrected in accordance with
“Acceptability of Work”. When the paving contractor is assured that all tolerances are being
met, finish rolling should begin.
J. Deficient areas within the base course should be corrected by saw cutting or milling high spots
and/or by truing and leveling low spots.
K. Deficient areas in the leveling/surface course should be corrected by saw cutting or milling to a
depth equal in thickness to the mat. A tack coat should be applied to all edges and the
pavement should be replaced. Skin patching of the leveling/surface course should only be done
with materials that are acceptable to the track surfacing contractor.
7.0 Acceptability of Work
A. Grade
Grade conformance tests should be conducted on both the base course and the leveling course.
The entire surface of the pavement should have positive drainage.
B. Planarity
After completion of the finish rolling operations on each course, the compacted surface should
be tested with a 10’ straightedge. Measurements should be made perpendicular to and across
all mats at a distance not to exceed every 25’ feet. The track surfacing contractor or
representative should be present when these measurements are made. The maximum
allowable planarity deviation within a pass should be ¼” in 10’ when measured in any direction.
8.0 Disclaimer
The above Asphalt Installation Guideline is provided for general assistance only. The responsibility
for warranties and performance guarantees for the proper preparation of the asphalt base rests
with the responsible professional, asphalt manufacturer and/or the asphalt sub-contractor in the
event of base failure and not with Traction. The general contractor, architect, and/or asphalt subcontractor will be notified by Traction if there is any sign of sub-floor defect or installation
conditions which could result in unsatisfactory performance. The responsibility for fixing defective
work rests with the general contractor and/or the asphalt sub-contractor.
Traction must be provided with the test results before visiting the project site. The owner can
obtain written confirmation from Traction, based on site observations and test results supplied by
the contractor, in which the bituminous concrete base appears satisfactorily finished and properly
cured to permit installation to begin. Traction will not be held responsible for any delays past
expected completion dates caused by the incorrect installation of the asphalt base and no penalties
will be held on Traction for this incorrect installation of the asphalt base. Any extra visits to the
project site due to the incorrect installation of the asphalt base will be at the general contractor,
sub-contractor or the owner’s expense.