USACE / NAVFAC / AFCESA / NASA UFGS-32 13 17 (August 2008)
---------------------------
Preparing Activity: USACE Superseding
UFGS-32 13 17 (January 2007)
UNIFIED FACILITIES GUIDE SPECIFICATIONS
References are in agreement with UMRL dated January 2009
SECTION 32 13 17
STONE MATRIX ASPHALT (SMA) FOR AIRFIELD PAVEMENTS
08/08
NOTE: This guide specification covers the requirements for stone matrix asphalt
(SMA) for both heavy duty roadway and airfield pavements.
Edit this guide specification for project specific requirements by adding, deleting,
or revising text. For bracketed items, choose applicable items(s) or insert
appropriate information.
Remove information and requirements not required in respective project, whether
or not brackets are present.
Comments and suggestions on this guide specification are welcome and should
be directed to the technical proponent of the specification. A listing of technical
proponents, including their organization designation and telephone number, is
on the Internet.
Recommended changes to a UFGS should be submitted as a Criteria Change Request
(CCR).
PART 1 GENERAL
NOTE: This guide specification only pertains to the stone matrix asphalt aspects
of the project and not to any surface preparation requirements dealing with
aggregate base courses, milling, or tack or prime coats. Surface preparation
requirements should be covered by either including them in this guide specification
or by adding pertinent sections to the project documents.
SMA can be used as a surface course for any airfield pavement. SMA provides
increased durability, resistance to rutting, resistance to reflective cracking
over HMA. Local state highway experiences with SMA should be considered when
developing the job specification.
This specification utilizes a Quality Assurance and Quality Control (QA/QC)
construction management philosophy. Quality Assurance refers to the actions
performed by the Government or designated representative Engineer to assure
the final product meets the job requirements. Results of QA testing are the
basis for pay. Quality Control refers to the actions of the Contractor to monitor
the construction and production processes and to correct these processes when
out of control. Results of QC testing are reported daily on the process control
charts maintained by the Contractor. Quality Control is covered in paragraph
CONTRACTOR QUALITY CONTROL.
1.1 METHOD OF MEASUREMENT
NOTE: For unit-price contracts, include first bracketed statements and delete
the second set. For lump-sum contracts, delete the first bracketed statements
and include the second set. Lump-sum contracts should not be used when the
job exceeds 1000 metric tons (1000 short tons).
[The amount paid for will be the number of [metric] [short] tons of SMA used in the accepted work. Weigh the
SMA after mixing, and no adjustment will be made for weight of asphalt cement material incorporated herein.
The measured quantity will be divided by the mix adjustment factor (MAF) to determine the pay quantity. The
MAF equals the maximum theoretical specific gravity from the JMF divided by 2.500. If the MAF calculation results
in a value less than or equal to 1.020 and greater than or equal to 0.98, then the MAF shall be considered to
be 1.000. If the calculated MAF is outside the range, then the actual calculated value shall be used.][Measurement
of the quantity of SMA, per [metric] [short] ton placed and accepted, shall be made for the purposes of assessing
the pay factors stipulated in this section.]
1.2 BASIS OF PAYMENT
NOTE: For unit-price contracts, include first bracketed statements and delete
the second set. For lump-sum contracts, delete the first bracketed statements
and include the second set. Include prescriptive unit price based on the Government/Engineer
estimate for payment adjustment. Lump-sum contracts should not be used when
the job exceeds 1000 metric tons (1000 tons).
[Quantities of SMA mixture, determined as specified above, will be paid for at respective contract unit prices
or at reduced prices adjusted in accordance with paragraphs PERCENT PAYMENT and QUALITY ASSURANCE. Payment will
constitute full compensation for furnishing all materials, equipment, plant, and tools; and for all labor and
other incidentals necessary to complete work required by this section of the specification.][The measured quantity
of SMA will be paid for and included in the lump-sum contract price. If less than 100 percent payment is due
based on the pay factors stipulated in paragraph QUALITY ASSURANCE, a unit price of [_____] per ton will be used
for purposes of calculating the payment reduction.]
1.3 PERCENT PAYMENT
When a lot of material fails to meet the specification requirements for 100 percent pay as outlined in the following
paragraphs, that lot shall be removed and replaced, or accepted at a reduced price which will be computed by
multiplying the unit price by the lot pay factor. The lot pay factor is determined by taking the lowest computed
pay factor based on either laboratory air voids, in place density, grade or smoothness (each discussed below).
Pay factors based on different criteria (i.e., laboratory air voids and in place density) of the same lot will
not be multiplied together to get a lower lot pay factor. At the end of the project, an average of all lot pay
factors will be calculated. If this average lot pay factor exceeds 95.0 percent, then the percent payment for
the entire project will be 100 percent of the unit bid price. If the average lot pay factor is less than 95.0
percent, then each lot will be paid for at the unit price multiplied by that lot's pay factor. For any lots
which are less than 2000 metric 2000 pound tons, a weighted lot pay factor will be used to calculate the average
lot pay factor.
1.3.1 Mat and Joint Densities
The average in place mat and joint densities are expressed as a percentage of the average maximum theoretical
density for the lot. The maximum theoretical density for each lot will be determined as the average maximum
theoretical density of the two random samples per lot. The average in place mat density and joint density for
a lot are determined and compared with Table 1 to calculate a single pay factor per lot based on in place density,
as described below. First, a pay factor for both mat density and joint density are determined from Table 1.
The area associated with the joint is then determined and will be considered to be 3 meters 10 feet wide times
the length of completed longitudinal construction joint in the lot. This area will not exceed the total lot
size. The length of joint to be considered will be that length where a new lane has been placed against an adjacent
lane of SMA pavement, either an adjacent freshly paved lane or one paved at any time previously. The area associated
with the joint is expressed as a percentage of the total lot area. A weighted pay factor for the joint is determined
based on this percentage (see example below). The pay factor for mat density and the weighted pay factor for
joint density are compared and the lowest selected. This selected pay factor is the pay factor based on density
for the lot. When the maximum theoretical density on both sides of a longitudinal joint is different, the average
of these two densities will be used as the maximum theoretical density needed to calculate the percent joint
density. All density results for a lot will be completed and reported within 24 hours after the construction
of that lot.
Table 1 Pay Factor Based on In-Place Density
Average Mat Density Pay Factor, Average Joint Density
(4 Cores) Percent (4 Cores)
94.0 or 96.0 100.0 above 92.5
93.9 100.0 92.4
93.8 or 96.1 99.9 92.3
93.7 99.8 92.2
93.6 or 96.2 99.6 92.1
93.5 99.4 92.0
93.4 or 96.3 99.1 91.9
93.3 98.7 91.8
93.2 or 96.4 98.3 91.7
93.1 97.8 91.6
93.0 or 96.5 97.3 91.5
92.9 96.3 91.4
92.8 or 96.6 94.1 91.3
92.7 92.2 91.2
92.6 or 96.7 90.3 91.1
92.5 87.9 91.0
92.4 or 96.8 85.7 90.9
92.3 83.3 90.8
92.2 or 96.9 80.6 90.7
92.1 78.0 90.6
92.0 or 97.0 75.0 90.5
below 92.0, above 101.0 0.0 (reject) below 90.5
1.3.2 Pay Factor Based on In-Place Density
An example of the computation of a pay factor (in inch-pound units only) based on in place density, is as follows:
Assume the following test results for field density made on the lot: (1) Average mat density = 93.2 percent
(of maximum theoretical density), (2) Average joint density = 91.0 percent (of maximum theoretical density),
(3) Total area of lot = 30,000 square feet, (4) Length of completed longitudinal construction joint = 2000 feet.
a. Step 1: Determine pay factor based on mat density and on joint density, using Table 1:
Mat density of 93.2 percent = 98.3 pay factor
Joint density of 91.5 percent = 97.3 pay factor
b. Step 2: Determine ratio of joint area (length of longitudinal joint x 10 ft) to mat area (total
paved area in the lot): Multiply the length of completed longitudinal construction joint by the specified
10 ft width and divide by the mat area (total paved area in the lot).
(2000 ft. x 10 ft)/30000 sq ft = 0.6667 ratio of joint area to mat area (ratio)
c. Step 3: Weighted pay factor (wpf) for joint is determined as indicated below:
wpf = joint pay factor + (100 - joint pay factor) (1 - ratio) wpf = 97.3 + (100-97.3) (1-0.6667)
= 98.2 percent
d. Step 4: Compare weighted pay factor for joint density to pay factor for mat density and select the
smaller:
Pay factor for mat density: 98.3 percent. Weighted pay factor for joint density: 98.2 percent.
Select the smaller of the two values as pay factor based on density: 98.2 percent.
1.3.3 Payment Adjustment for Smoothness
a. Straightedge Testing. Location and deviation from straightedge for all measurements shall be recorded.
When between 5.0 and 10.0 percent of all measurements made within a lot exceed the tolerance specified
in paragraph Smoothness Requirements below, after any reduction of high spots or removal and replacement,
the computed pay factor for that lot based on surface smoothness, will be 95 percent. When more than
10.0 percent of all measurements exceed the tolerance, the computed pay factor will be 90 percent. When
between 15.0 and 20.0 percent of all measurements exceed the tolerance, the computed pay factor will
be 75 percent. When 20.0 percent or more of the measurements exceed the tolerance, the lot shall be
removed and replaced at no additional cost to the Government-Owner. Regardless of the above, any small
individual area with surface deviation which exceeds the tolerance given above by more than 50 percent,
shall be corrected by diamond grinding to meet the specification requirements above or shall be removed
and replaced at no additional cost to the Government.
b. Profilograph Testing. Location and data from all profilograph measurements shall be recorded.
When the Profile Index of a lot exceeds the tolerance specified in paragraph Smoothness Requirements
above by 16 mm/km1.0 inch/mile, but less than 32 mm/km 2.0 inches/mile, after any reduction of high spots
or removal and replacement, the computed pay factor for that lot based on surface smoothness will be
95 percent. When the Profile Index exceeds the tolerance by 32 mm/km 2.0 inches/mile, but less than
47 mm/km 3.0 inches/mile, the computed pay factor will be 90 percent. When the Profile Index exceeds
the tolerance by 47 mm/km 3.0 inches/mile, but less than 63 mm/km 4.0 inches/mile, the computed pay factor
will be 75 percent. When the Profile Index exceeds the tolerance by 63 mm/km 4.0 inches/mile or more,
the lot shall be removed and replaced at no additional cost to the Government. Regardless of the above,
any small individual area with surface deviation which exceeds the tolerance given above by more than
79 mm/km 5.0 inches/mile or more, shall be corrected by grinding to meet the specification requirements
above or shall be removed and replaced at no additional cost to the Government.
1.3.4 Laboratory Air Voids and Theoretical Maximum Density
Laboratory air voids will be calculated in accordance with ASTM D 3203 by determining the density of each lab
compacted specimen using ASTM D 2726 and determining the theoretical maximum density (TMD) of every other sublot
sample using ASTM D 2041. Laboratory air void calculations for each sublot will use the latest theoretical maximum
density values obtained, for either that sublot or the previous sublot. The mean absolute deviation of the four-laboratory
air void contents (one from each sublot) from the JMF air void content will be evaluated and a pay factor determined
from Table 2. All laboratory air void tests will be completed and reported within 24 hours after completion
of construction of each lot. The TMD is also used for computation of compaction, as required in paragraph:
Mat and Joint Densities above.
Table 2 Pay Factor Based on Laboratory Air Voids
Mean Absolute Deviation of Lab Air Voids from JMF Pay Factor, percent
0.60 or less 100
0.61 - 0.80 98
0.81 - 1.00 95
1.01 - 1.20 90
Above 1.20 0 (reject)
1.3.5 Mean Absolute Deviation
An example of the computation of mean absolute deviation for laboratory air voids is as follows: Assume that
the laboratory air voids are determined from 4 random samples of a lot (where 3 specimens were compacted from
each sample). The average laboratory air voids for each sublot sample are determined to be 3.5, 3.0, 4.0, and
3.7. Assume that the target air voids from the JMF is 4.0. The mean absolute deviation is then:
Mean Absolute Deviation = ( 3.5 - 4.0 + 3.0 - 4.0 + 4.0 - 4.0 +
3.7 - 4.0 )/4 = (0.5 + 1.0 + 0.0 + 0.3)/4 = (1.8)/4 = 0.45
The mean absolute deviation for laboratory air voids is determined to be 0.45. It can be seen from Table 2 that
that lot's pay factor based on laboratory air voids is 100 percent.
1.3.6 Pay Adjustment Based on Grade
NOTE: The grade and surface smoothness requirements specified below are for
the final wearing surface only. If there is a requirement to test and control
the grade and smoothness for the intermediate courses, i.e., when the intermediate
courses will be exposed to traffic, slight modifications to this specification
will be required.
Within 5 working days after completion of a particular lot incorporating the final wearing course, test the final
wearing surface for conformance with specified plan grade requirements. Detailed notes of the results of the
testing shall be kept and a copy furnished to the Government immediately after each day's testing. The final
wearing surface of pavement shall conform to the elevations and cross sections shown and shall vary not more
than 9 mm 0.03 foot for runways or 15 mm 0.05 foot for taxiways and aprons from the plan grade established and
approved at site of work. Finished surfaces at juncture with other pavements shall coincide with finished surfaces
of abutting pavements. Deviation from the plan elevation will not be permitted in areas of pavements where closer
conformance with planned elevation is required for the proper functioning of drainage and other appurtenant structures
involved. The grade will be determined by running lines of levels at intervals of 7.6 meters 25 feet, or less,
longitudinally and transversely, to determine the elevation of the completed pavement surface. When more than
5 percent of all measurements made within a lot are outside the 9 or 15 mm 0.03 or 0.05 foot tolerance, the pay
factor based on grade for that lot will be 95 percent. In areas where the grade exceeds the tolerance by more
than 50 percent, remove the surface lift full depth; then replace the lift with SMA to meet specification requirements,
at no additional cost to the Government. Diamond grinding may be used to remove high spots to meet grade requirements.
Skin patching for correcting low areas or planing or milling for correcting high areas will not be permitted.
1.4 REFERENCES
NOTE: This paragraph is used to list the publications cited in the text of
the guide specification. The publications are referred to in the text by basic
designation only and listed in this paragraph by organization, designation,
date, and title.
Use the Reference Wizard's Check Reference feature when you add a RID outside
of the Section's Reference Article to automatically place the reference in the
Reference Article. Also use the Reference Wizard's Check Reference feature
to update the issue dates.
References not used in the text will automatically be deleted from this section
of the project specification when you choose to reconcile references in the
publish print process.
The publications listed below form a part of this specification to the extent referenced. The publications are
referred to within the text by the basic designation only.
[AMERICAN ASSOCIATION OF STATE HIGHWAY AND TRANSPORTATION OFFICIALS (AASHTO)AASHTO M 320(2005) Performance-Graded Asphalt BinderAASHTO M 325(2008) Standard Specification for Stone Matrix Asphalt (SMA)AASHTO R 46(2008) Standard Practice for Designing Stone Matrix Asphalt (SMA)AASHTO T 312(2008) Preparing and Determining the Density of Hot Mixed Asphalt (HMA) Specimens By Means of the Superpave Gyratory Compactor][ASPHALT INSTITUTE (AI)AI MS-02(6th Edition; 1997) Mix Design Methods for Asphalt][ASTM INTERNATIONAL (ASTM)ASTM C 117(2004) Standard Test Method for Materials Finer than 75-um (No. 200) Sieve in Mineral Aggregates by WashingASTM C 1252(2006) Standard Test Methods for Uncompacted Void Content of Fine Aggregate (as Influenced by Particle Shape, Surface Texture, and Grading)ASTM C 127(2007) Standard Test Method for Density, Relative Density (Specific Gravity), and Absorption of Coarse AggregateASTM C 128(2007a) Standard Test Method for Density, Relative Density (Specific Gravity), and Absorption of Fine AggregateASTM C 131(2006)Standard Test Method for Resistance to Degradation of Small-Size Coarse Aggregate by Abrasion and Impact in the Los Angeles MachineASTM C 136(2006) Standard Test Method for Sieve Analysis of Fine and Coarse AggregatesASTM C 566(1997; R 2004) Standard Test Method for Total Evaporable Moisture Content of Aggregate by DryingASTM C 612(2004e1) Mineral Fiber Block and Board Thermal InsulationASTM C 88(2005) Standard Test Method for Soundness of Aggregates by Use of Sodium Sulfate or Magnesium SulfateASTM D 140(2001; R 2007) Sampling Bituminous MaterialsASTM D 2041(2003a) Theoretical Maximum Specific Gravity and Density of Bituminous Paving MixturesASTM D 2172(2005) Quantitative Extraction of Bitumen from Bituminous Paving MixturesASTM D 2419(2002) Sand Equivalent Value of Soils and Fine AggregateASTM D 242(2004) Mineral Filler for Bituminous Paving MixturesASTM D 2489/D 2489M(2008) Estimating Degree of Particle Coating of Bituminous-Aggregate MixturesASTM D 2726(2008) Bulk Specific Gravity and Density of Non-Absorptive Compacted Bituminous MixturesASTM D 2950(2005) Density of Bituminous Concrete in Place by Nuclear MethodsASTM D 3203(2005) Percent Air Voids in Compacted Dense and Open Bituminous Paving MixturesASTM D 3381(2005) Viscosity-Graded Asphalt Cement for Use in Pavement ConstructionASTM D 3665(2007) Random Sampling of Construction MaterialsASTM D 3666(2007e1) Minimum Requirements for Agencies Testing and Inspecting Road and Paving MaterialsASTM D 4125(2005) Asphalt Content of Bituminous Mixtures by the Nuclear MethodASTM D 4318(2005) Liquid Limit, Plastic Limit, and Plasticity Index of SoilsASTM D 4791(2005e1) Flat Particles, Elongated Particles, or Flat and Elongated Particles in Coarse AggregateASTM D 4867/D 4867M(2004) Effect of Moisture on Asphalt Concrete Paving MixturesASTM D 5444(2008) Mechanical Size Analysis of Extracted AggregateASTM D 6307(2005) Asphalt Content of Hot Mix Asphalt by Ignition MethodASTM D 6390(2005) Determination of Draindown Characteristics in Uncompacted Asphalt MixturesASTM D 75(2003) Standard Practice for Sampling AggregatesASTM D 946(1982; R 2005) Penetration-Graded Asphalt Cement for Use in Pavement ConstructionASTM D 979(2001; R 2006e1) Sampling Bituminous Paving MixturesASTM D 995(1995b; R 2002) Mixing Plants for Hot-Mixed, Hot-Laid Bituminous Paving Mixtures][STATE OF CALIFORNIA DEPARTMENT OF TRANSPORTATION (CDT)CDT Test 526(2002) Operation of California Profilograph and Evaluation of Profiles][U.S. ARMY CORPS OF ENGINEERS (USACE)COE CRD-C 171(1994) Standard Test Method for Determining Percentage of Crushed Particles in Aggregate]1.5 SYSTEM DESCRIPTION
Perform the work consisting of pavement courses composed of mineral aggregate, polymer-modified asphalt material,
and a stabilizer, mixed in a central mixing plant. The hot mixture is placed with an asphalt paver on a prepared
course. Stone matrix asphalt (SMA) mixtures designed and constructed in accordance with these specifications
shall conform to the lines, grades, thicknesses, and typical cross sections shown on the drawings. Provide plants
used for the preparation of SMA conforming to the requirements of ASTM D 995 with the changes listed below:
1.5.1 Truck Scales
Weigh the asphalt mixture on approved scales furnished by the Contractor, or on certified public scales at the
Contractor's expense. Scales shall be inspected and sealed at least annually by an approved calibration laboratory.
1.5.2 Testing Facilities
Provide laboratory facilities at the plant for the use of the Government Engineer's acceptance testing and the
Contractor's quality control testing.
1.5.3 Inspection of Plant
The Contracting Officer/Engineer shall have access at all times, to all areas of the plant for checking adequacy
of equipment; inspecting operation of the plant; verifying weights, proportions, and material properties; checking
the temperatures maintained in the preparation of the mixtures and for taking samples. Provide assistance, as
requested, for the Government Engineer to procure any desired samples.
1.5.4 Storage Bins
The SMA mixture may be stored in non-insulated storage bins for a period of time not to exceed 2 hours. The
SMA mixture may be stored in insulated storage bins for a period of time not exceeding 4 hours. The mix drawn
from bins shall meet the same requirements as mix loaded directly into trucks.
1.5.5 Hauling Equipment
Trucks used for hauling SMA shall have tight, clean, and smooth metal beds. To prevent the mixture from adhering
to them, the truck beds shall be lightly coated with a minimum amount of paraffin oil, lime solution, or other
approved material. Petroleum based products shall not be used as a release agent. Each truck shall have a suitable
cover to protect the mixture from adverse weather. When necessary to ensure that the mixture will be delivered
to the site at the specified temperature, truck beds shall be insulated or heated, and covers (tarps) shall be
securely fastened.
1.5.6 Asphalt Pavers
Provide asphalt pavers which are self-propelled, with an activated screed, heated as necessary, and capable of
spreading and finishing SMA which will meet the specified thickness, smoothness, and grade. The paver shall
have sufficient power to propel itself and the hauling equipment without adversely affecting the finished surface.
1.5.6.1 Receiving Hopper
The paver shall have a receiving hopper of sufficient capacity to permit a uniform spreading operation. The
hopper shall be equipped with a distribution system to place the mixture uniformly in front of the screed without
segregation. The screed shall effectively produce a finished surface of the required evenness and texture without
tearing, shoving, or gouging the mixture.
1.5.6.2 Automatic [Grade] [Screed] Controls
NOTE: Select automatic grade control when the design requires elevations for
the SMA surface. Most specifications require an overlay thickness and do not
specify actual grades; therefore, select or delete the information below within
the brackets.
[The automatic grade control device shall consist of a control system capable of automatically maintaining the
paver screed at the specified elevation. The control system shall be automatically actuated from either a reference
line and/or through a system of mechanical sensors or sensor-directed mechanisms or devices which will maintain
the paver screed at a predetermined transverse slope and at the proper elevation to obtain the required surface.
The transverse slope controller shall be capable of maintaining the screed at the desired slope within plus or
minus 0.1 percent. A transverse slope controller shall not be used to control grade. The controls shall be
capable of working in conjunction with any of the following attachments:
a. Ski-type device of not less than 9.14 meters 30 feet in length.
b. Taut stringline set to grade.
c. Short ski or shoe for joint matching.
d. Laser control.]
[The automatic screed control device shall consist of a control system capable of automatically controlling the
elevation of the paver screed according to the inputs received. The control system shall be automatically actuated
from a system of mechanical sensors or sensor-directed mechanisms or devices that will maintain the paver screed
at the proper elevation to obtain the required surface thickness and smoothness. The controls shall be capable
of working in conjunction with any of the following attachments:
a. Ski-type device of not less than 9.14 meters 30 feet in length.
b. Short ski or shoe for joint matching.]
1.5.7 Rollers
Rollers shall be in good condition and shall be operated at slow speeds to avoid displacement of the SMA mixture.
The number, type, and weight of rollers shall be sufficient to compact the mixture to the required density.
Rollers that cause crushing of the aggregate shall not be used. Rubber-tired rollers shall not be used.
1.6 SUBMITTALS
NOTE: Review submittal description (SD) definitions in Section 01 33 00 SUBMITTAL
PROCEDURES and edit the following list to reflect only the submittals required
for the project. Submittals should be kept to the minimum required for adequate
quality control.
A “G” following a submittal item indicates that the submittal requires Government
approval. Some submittals are already marked with a “G”. Only delete an existing
“G” if the submittal item is not complex and can be reviewed through the Contractor’s
Quality Control system. Only add a “G” if the submittal is sufficiently important
or complex in context of the project.
For submittals requiring Government approval on Army projects, a code of up
to three characters within the submittal tags may be used following the "G"
designation to indicate the approving authority. Codes for Army projects using
the Resident Management System (RMS) are: "AE" for Architect-Engineer; "DO"
for District Office (Engineering Division or other organization in the District
Office); "AO" for Area Office; "RO" for Resident Office; and "PO" for Project
Office. Codes following the "G" typically are not used for Navy, Air Force,
and NASA projects.
Choose the first bracketed item for Navy, Air Force and NASA projects, or choose
the second bracketed item for Army projects.
Government approval is required for submittals with a "G" designation; submittals not having a "G" designation
are for [Contractor Quality Control approval.] [information only. When used, a designation following the "G"
designation identifies the office that will review the submittal for the Government.] Submit the following in
accordance with Section 01 33 00 SUBMITTAL PROCEDURES:
SD-03 Product Data
Mix Design[; G][; G, [_____]]
Proposed JMF.
Contractor Quality Control[; G][; G, [_____]]
Quality control plan.
SD-04 Samples
Asphalt Cement Binder
20 L 5 gallons sample for mix design verification.
Aggregates
Sufficient materials to produce 90 kg 200 lbs of blended mixture for mix design verification.
SD-06 Test Reports
Aggregates[; G][; G, [_____]]
QC Monitoring[; G][; G, [_____]]
Aggregate and QC test results.
SD-07 Certificates
Asphalt Cement Binder[; G][; G, [_____]]
Fiber Stabilizer[; G][; G, [_____]]
Copies of certified test data.
Testing Laboratory
Certification of compliance.
1.7 QUALITY ASSURANCE
NOTE: It is highly recommended to keep the Government's QA testing separate
and distinct from the Contractor's QC testing. However, it is recognized that
in house testing capability to provide the QA testing required by this section
will not always be available; in this case, it is recommended that an independent
material testing company be hired to provide the QA testing for the project.
The cost of this testing to assure good long-term performance is very small
relative to the overall cost of the construction, and especially compared to
the cost of a pavement failure.
Although not recommended, this guide specification may be modified to require
the Contractor to hire an independent material-testing laboratory to perform
the QA testing listed in this section. The results would need to be forwarded
daily to the Contracting Officer as the basis for acceptance and pay. This
should only be done if there is no way of hiring an independent testing laboratory
to perform the QA testing.
The QA testing program includes material tests to determine laboratory air voids
and in place density, which are needed to determine percent payment. The project
engineer may choose to have additional tests conducted by the QA test agency
to monitor aggregate gradation, asphalt content. These tests would serve as
a check to the Contractor's QC testing. This additional testing, if conducted,
is not included as part of this specification since the parameters are not used
as a basis of pay.
The Government's quality assurance (QA) program for this project will be separate and distinct from the Contractor's
quality control (QC) program specified in PART 3. Testing for acceptability of work will be performed by the
Government or by an independent laboratory hired by the Contracting Officer, except for smoothness and grade
testing which shall be performed by the Contractor. Acceptance of the plant produced mix and in place requirements
will be on a lot to lot basis. A standard lot for all requirements will be equal to 2000 metric 2000 short tons.
Where appropriate, adjustment in payment for individual lots of SMA will be made based on in place density, laboratory
air voids, grade and smoothness in accordance with the following paragraphs. Grade and surface smoothness determinations
will be made on the lot as a whole. Exceptions or adjustments to this will be made in situations where the mix
within one lot is placed as part of both the intermediate and surface courses, thus grade and smoothness measurements
for the entire lot cannot be made. In order to evaluate laboratory air voids and in place (field) density, each
lot will be divided into four equal sublots.
1.7.1 Sublot Sampling
One random mixture sample for determining laboratory air voids, theoretical maximum density, and for any additional
testing the Contracting Officer desires, will be taken from a loaded truck delivering mixture to each sublot,
or other appropriate location for each sublot. All samples will be selected randomly, using commonly recognized
methods of assuring randomness conforming to ASTM D 3665 and employing tables of random numbers or computer programs.
Laboratory air voids will be determined from three laboratory compacted specimens of each sublot sample. The
specimens will be compacted within 2 hours of the time the mixture was loaded into trucks at the asphalt plant.
Samples will not be reheated prior to compaction and insulated containers will be used as necessary to maintain
the temperature.
1.7.2 Additional Smpling and Testing
The Contracting Officer reserves the right to direct additional samples and tests for any area which appears
to deviate from the specification requirements. The cost of any additional testing will be paid for by the Government.
Testing in these areas will be in addition to the lot testing, and the requirements for these areas will be the
same as those for a lot.
1.7.3 In-Place Density
For determining in place density, one random core (100 to 150 mm 4 to 6 inches in diameter) will be taken by
the Government from the mat (interior of the lane) of each sublot, and one random core will be taken from the
joint (immediately over joint) of each sublot in accordance with ASTM D 979. Each random core will be full thickness
of the layer being placed. When the random core is less than 25 mm 1 inch thick, it will not be included in
the analysis. In this case, another random core will be taken. After air-drying in accordance with ASTM D 2726
for laboratory prepared, thoroughly dry specimens, cores obtained from the mat and from the joints will be used
for in place density determination.
1.7.4 Surface Smoothness
NOTE: Edit these paragraphs as appropriate to the project. It is desired to
restrict surface smoothness testing and evaluation to either straightedge method
or profilograph method. Retain the one and delete the other; otherwise, retain
both as a Contractor's option. Generally, designer should require use of the
profilograph method. If the profilograph method is allowed, and there are areas
with dimensions less than 60 meters (200 feet) in any direction, part of the
straightedge method must be retained for these short runs.
Use [one] [both] of the following methods to test and evaluate surface smoothness of the pavement. Perform all
testing in the presence of the Contracting Officer. Keep detailed notes of the results of the testing with a
copy furnished to the Government immediately after each day's testing. Use the profilograph method for all longitudinal
and transverse testing, except where the runs would be less than 60 meters 200 feet in length and the ends where
the straightedge shall be used. Where drawings show required deviations from a plane surface (crowns, drainage
inlets, etc.), the surface shall be finished to meet the approval of the Contracting Officer.
1.7.5 Smoothness Requirements
a. Straightedge Testing: The finished surfaces of the pavements shall have no abrupt change of 3 mm
1/8 inch or more, and all pavements shall be within the tolerances specified in Table 3 when checked
with an approved 4-meter 12-foot straightedge.
Table 3 Straightedge Surface Smoothness-Pavements
Pavement Category Direction of Testing Tolerance, mm
Runways and taxiways Longitudinal 3
Transverse 6
Calibration hardstands and Longitudinal 3
compass swinging bases Transverse 3
All other airfield and Longitudinal 6
helicopter paved areas Transverse 6
Table 3 Straightedge Surface Smoothness-Pavements
Pavement Category Direction of Testing Tolerance, inch
Runways and taxiways Longitudinal 1/8
Transverse 1/4
Calibration hardstands and Longitudinal 1/8
compass swinging bases Transverse 1/8
All other airfield and Longitudinal 1/4
helicopter paved areas Transverse 1/4
b. Profilograph Testing: The finished surfaces of the pavements shall have no abrupt change of 3 mm
1/8 inch or more, and all pavement shall have a Profile Index not greater than specified in Table 4
when testing with an approved California-type profilograph. If the extent of the pavement in either
direction is less than 60 meters 200 feet, that direction shall be tested by the straightedge method
and shall meet requirements specified above.
Table 4 Profilograph Surface Smoothness Pavements
Maximum Specified
Profile Index
Pavement Category Direction of Testing (mm/km)
Runways Longitudinal 110
Transverse 140
Taxiways Longitudinal 140
Transverse (Use Straightedge)
Calibration hardstands and (Use Straightedge)
compass swinging bases
All other airfield and Longitudinal 140
helicopter paved areas Transverse 140
Table 4 Profilograph Surface Smoothness Pavements
Maximum Specified
Profile Index
Pavement Category Direction of Testing (inch/mile)
Runways Longitudinal 7
Transverse 9
Taxiways Longitudinal 9
Transverse (Use Straightedge)
Calibration hardstands and (Use Straightedge)
compass swinging bases
All other airfield and Longitudinal 9
helicopter paved areas Transverse 9
1.7.6 Testing Method
After the final rolling, but not later than 24 hours after placement, the surface of the pavement in each entire
lot shall be tested by the Contractor in such a manner as to reveal all surface irregularities exceeding the
tolerances specified above. Separate testing of individual sub lots is not required. If any pavement areas
are ground, these areas shall be retested immediately after grinding. The entire area of the pavement shall
be tested in both a longitudinal and a transverse direction on parallel lines. The transverse lines shall be
4.5 meters 15 feet or less apart, as directed. The longitudinal lines shall be at the centerline of each paving
lane for lines less than 6.1 meters 20 feet and at the third points for lanes 6.1 meters 20 feet or greater.
Other areas having obvious deviations shall also be tested. Longitudinal testing lines shall be continuous across
all joints.
a. Straightedge Testing. Hold the straightedge in contact with the surface and move ahead one-half
the length of the straightedge for each successive measurement. Determine the amount of surface irregularity
by placing the freestanding (unleveled) straightedge on the pavement surface and allowing it to rest
upon the two highest spots covered by its length, and measuring the maximum gap between the straightedge
and the pavement surface in the area between these two high points.
b. Profilograph Testing. Perform profilograph testing using approved equipment and procedures described
in CDT Test 526. The equipment shall utilize electronic recording and automatic computerized reduction
of data to indicate "must-grind" bumps and the Profile Index for the pavement. The "blanking band" shall
be 5 mm 0.2 inches wide and the "bump template" shall span 25 mm 1 inch with an offset of 10 mm 0.4 inch
. The profilograph shall be operated by an approved, factory-trained operator on the alignments specified
above. Furnish a copy of the reduced tapes to the Government at the end of each day's testing.
c. Bumps. ("Must Grind" Areas). Any bumps ("must grind" areas) shown on the profilograph trace which
exceed 10 mm 0.4 inch in height shall be reduced by diamond grinding until they do not exceed 7.5 mm
0.3 inch when retested. Such grinding shall be tapered in all directions to provide smooth transitions
to areas not requiring grinding. The following will not be permitted: (1) skin patching for correcting
low areas, (2) planing or milling for correcting high areas. At the Contractor's option, pavement areas,
including ground areas, may be rechecked with the profilograph in order to record a lower Profile Index.
1.8 ENVIRONMENTAL REQUIREMENTS
NOTE: The temperature requirements are included to avoid problems with the
Contractor achieving density because the mix cools too fast. Waivers to these
requirements, for isolated incidences during production, are applicable if the
density requirements are still met.
Do not place the SMA upon a wet surface or when the surface temperature of the underlying course is less than
7 degrees C 45 degrees F. The temperature requirements may be waived by the Contracting Officer, if requested;
however, all other requirements, including compaction, shall be met.
PART 2 PRODUCTS
2.1 AGGREGATES
NOTE: One objective in the design of SMA is to produce a mixture with stone-on-stone
aggregate contact. This requires hard, durable, highly fractured aggregates.
Include only sources with a satisfactory performance record under similar conditions
of service and exposure.
Aggregates shall consist of crushed stone, [crushed gravel,] [crushed steel slag,] screenings, and mineral filler,
as required. The portion of material retained on the 4.75 mm No. 4 sieve is coarse aggregate. The portion of
material passing the 4.75 mm No. 4 sieve and retained on the 0.075 mm No. 200 sieve is fine aggregate. The portion
passing the 0.075 mm No. 200 sieve is defined as mineral filler. All aggregate test results and samples shall
be submitted to the Contracting Officer at least 14 days prior to start of construction.
2.1.1 Coarse Aggregate
NOTE: The requirement for magnesium sulfate (requirement b., below) may be
deleted in climates where freeze-thaw does not occur. However, in these areas
where freeze-thaw does not occur, requirement b., should remain if experience
has shown that this test separates good performing aggregates from bad performing
aggregates.
Coarse aggregate shall consist of sound, tough, durable particles, free from films of material that would prevent
thorough coating and bonding with the asphalt material and free from organic matter and other deleterious substances.
[Steel slag may be used. ]The coarse aggregate particles shall meet the following requirements:
a. The percentage of loss shall not be greater than 30 percent after 500 revolutions when tested in
accordance with ASTM C 131.
b. The percentage of loss shall not be greater than 18 percent after five cycles when tested in accordance
with ASTM C 88 using magnesium sulfate.
c. At least 100 percent by weight of coarse aggregate shall have at least two or more fractured faces
when tested in accordance with COE CRD-C 171. Fractured faces shall be produced by crushing.
d. The particle shape shall be essentially cubical and the aggregate shall not contain more than 20
percent, by weight, of flat and elongated particles (3:1 ratio of maximum to minimum) and no more than
5 percent, by weight, of flat and elongated particles (5:1 ratio of maximum to minimum) when tested in
accordance with ASTM D 4791.
e. The maximum absorption shall not be greater than 2 percent when tested in accordance with ASTM C 127
.
2.1.2 Fine Aggregate
NOTE: The lower limit for uncompacted void content (requirement c., below)
should be set at 45 for fine aggregate angularity unless local experiences indicate
that a lower value can be used. There are some aggregates which have a good
performance record and have an uncompacted void content less than 45. In no
case should the limit be set less than 43.
Fine aggregate shall consist of clean, sound, tough, durable particles. The aggregate particles shall be free
from coatings of clay, silt, or any objectionable material and shall contain no clay balls. The fine aggregate
particles shall meet the following requirements:
a. The fine aggregate portion of the blended aggregate shall be 100 percent crushed manufactured fines.
b. The individual fine aggregate sources shall have a sand equivalent value greater than 45 when tested
in accordance with ASTM D 2419.
c. The fine aggregate portion of the blended aggregate shall have an uncompacted void content greater
than 45.0 percent when tested in accordance with ASTM C 1252 Method A.
d. Aggregate shall be non-plastic, with a Liquid Limit of 25 percent maximum when tested in accordance
with ASTM D 4318.
e. The maximum absorption shall not be greater than 2 percent when tested in accordance with ASTM C 128
.
2.1.3 Mineral Filler
Mineral filler shall be non-plastic material meeting the requirements of ASTM D 242.
2.1.4 Aggregate Gradation
NOTE: Generally, the layer thickness should be at least 50 mm (2 inches).
The combined aggregate gradation shall conform to gradations specified in Table 5, when tested in accordance
with ASTM C 136 and ASTM C 117, and shall not vary from the low limit on one sieve to the high limit on the adjacent
sieve or vice versa, but grade uniformly from coarse to fine.
Table 5 Aggregate Gradations
Percent Passing
Sieve Size, mm by Mass
25.0 ---
19.0 100
12.5 90-100
9.5 50-85
4.7 20-40
2.36 16-28
1.18 -
0.60 -
0.30 -
0.15 -
0.075 8-11
Table 5 Aggregate Gradations
Percent Passing
Sieve Size, inch by Mass
1 ---
3/4 100
1/2 90-100
3/8 50-85
No. 4 20-40
No. 8 16-28
No. 16 -
No. 30 -
No. 50 -
No. 100 -
No. 200 8-11
2.1.5 Fiber Stabilizer
NOTE: Fibers, either cellulose or mineral, must be used in the SMA mixture.
The stabilizer can be cellulose or mineral fibers. Requirements and test procedures are outlined in Tables 6
and 7.
2.2 ASPHALT CEMENT BINDER
NOTE: Performance Graded (PG) asphalt binders should be specified wherever
available. Select the same grade PG binder used by the local highway agency
for that area (e.g., the grade typically specified in that specific location
for dense graded mixes on highways with design ESALs less than 10 million).
Bump (increase) the high temperature grade two grades higher and this should
be the grade of asphalt cement used for the project. The exception would be
that grades with a low temperature higher than PG XX 22 should not be used (e.g.
PG XX 16 or PG XX 10), unless the Engineer has had successful experience with
them. The Engineer may lower the low temperature grade to comply with the recommendations
of the FHWA's software program "LTPPBind," if it is believed to be appropriate.
Asphalt cement binder shall conform to AASHTO M 320, Performance Grade [_____]. [As An alternate,ASTM D 3381
Table 2, Viscosity Grade [______] or ASTM D 946 Penetration Grade [______] may be used]. Test data indicating
grade certification shall be provided by the supplier at the time of delivery of each load to the mix plant.
Copies of these certifications shall be submitted to the Contracting Officer. The supplier is defined as the
last source of any modification to the binder. The Contracting Officer/Engineer may sample and test the binder
at the mix plant at any time before or during mix production. Samples for this verification testing shall be
obtained by the Contractor in accordance with ASTM D 140 and in the presence of the Contracting Officer. These
samples shall be furnished to the Contracting Officer for the verification testing, which shall be at no cost
to the Contractor.
Table 6 Cellulose Fibers Quality Requirements
Properties Requirement
Sieve Analysis
Method A
Alpine Sieve(1) Analysis
Fiber length 6 mm (0.25 inch) (max)
Passing 150 micron (No. 100) sieve 70 percent (± 10%)
Method B
Mesh Screen(2) Analysis
Fiber length 6 mm (0.25 inch) (max)
Passing 850 micron (No. 20) sieve 85 percent (± 10%)
425 micron (No. 40) sieve 65 percent (± 10%)
106 micron (No. 140) sieve 30 percent (± 10%)
Ash Content(3) 18 percent (± 5%) non-
volatiles
pH(4) 7.5 (± 1.0)
Oil Absorption(5) 5.0 (± 1.0)(times fiber weight)
Moisture Content(6) <5% (by weight)
(1) This test is performed using an Alpine Air Jet Sieve (Type 200 LS). A representative 5-gram sample of fiber
is sieved for 14 minutes at a controlled vacuum of 75 kPa 11 psi. The portion remaining on the screen is weighed.
(2) This test is performed using standard 850, 425, 250, 180, 150, 106 micron No. 20, 40, 60, 80, 100, 140 sieves,
nylon brushes, and a shaker. A representative 10-gram sample of fiber is sieved using a shaker and two nylon brushes
on each screen. The amount retained on each sieve is weighed and the percentage passing calculated. The repeatability
of this method is suspect and needs to be verified.
(3) A representative 2-3 gram sample of fiber is placed in a tared crucible and heated between 595 and 650 degrees
C 1100 and 1200 degrees F for not less than 2 hours. The crucible and ash are cooled in a desiccator and reweighed.
(4) Five grams of fiber is added to 100 mL of distilled water, stirred, and let sit for 30 minutes. The pH is determined
with a probe calibrated with pH 7.0 buffer.
(5) Five grams of fiber is accurately weighed and suspended in an excess of mineral spirits for not less than 5 minutes
to ensure total saturation. It is then placed in a screen mesh strainer (approximately 0.5 square millimeter hole
size) and shaken on a wrist-action shaker for 10 minutes (approximately 31.75 mm 1 1/4 inch motion at 240 shakes/minute).
The shaken mass is then transferred without touching, to a tared container and weighed. Results are reported as
the amount (number of times its own weight) the fibers are able to absorb.
(6) Ten grams of fiber is weighed and placed in a 121 degree C 250 degrees F forced-air oven for 2 hours. The sample
is then reweighed immediately upon removal from the oven.
Table 7 Mineral Fibers Quality Requirements
Properties Requirement
Sieve Analysis
Fiber length(1) 6 mm (0.25 inch) max mean test value
Thickness(2) 0.005 mm (0.0002 inch) max mean test value
Shot content(3)
250 micron (No. 60) sieve 95 percent passing (min)
63 micron (No. 230) sieve 65 percent passing (min)
(1) The fiber length is determined according to the Baur McNett fractionation.
(2) The fiber diameter is determined by measuring at least 200 fibers in a phase contract microscope.
(3) Shot content is a measure of non-fibrous material. The shot content is determined on vibrating sieves. Two
sieves, No. 60 and No. 230, are typically utilized; for additional information see ASTM C 612.
2.3 MIX DESIGN
NOTE: Select bracketed AASHTO Superpave compaction test methods for vehicle
pavement. Select bracketed Asphalt Institute Marshall compaction test methods
for airfield pavement.
Develop the mix design. The asphalt mix shall be composed of a mixture of coarse and fine aggregate, mineral
filler, a stabilizer, and asphalt material. The aggregate fractions shall be sized, handled in separate size
groups, and combined in such proportions that the resulting mixture meets the grading requirements of the job
mix formula (JMF). No SMA for payment shall be produced until a JMF has been approved. The SMA shall be designed
using [AASHTO M 325, AASHTO R 46, and AASHTO T 312] [hand-held Marshall Hammer procedures contained in AI MS-02
] and meeting the criteria shown in Table 8. The aggregate quality requirements given in this specification
shall be used instead of those given in AASHTO M 325. If the Tensile Strength Ratio (TSR) of the composite mixture,
as determined by ASTM D 4867/D 4867M, is less than 75, the aggregate stripping tendencies shall be countered
by the use of hydrated lime or by treating the bitumen with an approved antistripping agent as furnished by the
Contractor. The hydrated lime will be considered as mineral filler and will be considered in the gradation requirements.
The amount of hydrated lime or antistripping agent added to the bitumen will be determined during development
of the JMF and will be sufficient to produce a TSR greater than 75 percent. Use of additional antistripping
agent may be directed during the progress of work, if necessary. Provide an anti-strip agent, if required, at
no additional cost. Sufficient materials to produce 90 kg 200 pounds of blended mixture shall be provided to
the Contracting Officer for verification of mix design at least 14 days prior to construction of test section.
2.3.1 JMF Requirements
NOTE: In Table 9, use a 50 blow (compactive effort) Marshall Mix for all SMA
pavements. If the JMF is designed using the hand-held Marshall Hammer according
to AI MS-02, delete element t, as given below.
Submit the job mix formula in writing, for approval, at least 14 days prior to the start of the test section
including as a minimum:
a. Percent passing each sieve size.
b. Percent of asphalt cement.
c. Percent of each aggregate and mineral filler to be used.
d. Asphalt viscosity grade, penetration grade, or performance grade.
e. Type and amount of stabilizer.
f. Laboratory mixing temperature.
g. Lab compaction temperature.
h. Temperature-viscosity relationship of the asphalt cement.
i. Plot of the combined gradation on the 0.45 power gradation chart, stating the nominal maximum size.
j. Specific gravity and absorption of each aggregate.
k. Percent particles with one and two or more fractured faces (in coarse aggregate).
l. Fine aggregate angularity.
m. Percent flat or elongated particles (in coarse aggregate).
n. Tensile Strength Ratio (TSR).
o. Antistrip agent (if required) and amount.
p. List of all modifiers and amount.
q. Percent draindown of mixture.
r. Dry-rodded-in-the coarse aggregate (VCADRC).
s. Voids-in-the coarse aggregate mixture (VCAMix).
t. Number of revolutions of SGC compactor.
Table 8 SMA Mix Design Criteria
Test Property 50 Blow Mix
Air voids, percent 3.0-4.0
Percent Voids in mineral aggregate (minimum) 17.0(1)
Tensile Strength Ratio (TSR), minimum percent 75
Draindown, percent (maximum) 0.3 (1 hour reading)(2)
(1) Calculate VMA in accordance with AI MS-02, based on ASTM D 2726 bulk specific gravity for the aggregate.
(2) Calculate Draindown in accordance with ASTM D 6390 determination of draindown characteristics in uncompacted
asphalt mixtures.
2.3.2 Adjustments to JMF
The JMF for each mixture shall be in effect until a new formula is approved in writing by the Contracting Officer.
Should a change in sources of any materials be made, a new mix design shall be performed and a new JMF approved
before the new material is used. The Contractor will be allowed to adjust the JMF within the limits specified
below in Table 5 to optimize mix volumetric properties. If adjustments are needed that exceed these limits,
a new mix design shall be developed. Tolerances given above may permit the aggregate grading to be outside the
limits shown in Table 1; this is acceptable.
Table 9 Job Mix Tolerances
Material Tolerance, Plus or Minus
Aggregate passing 4.75 mm or larger sieves 3 percent
Aggregate passing 2.36 mm or smaller sieves 2 percent
Asphalt cement 0.25 percent
Temperature of mixing 14 degrees C
Table 9 Job Mix Tolerances
Material Tolerance, Plus or Minus
Aggregate passing No. 4 or larger sieves 3 percent
Aggregate passing No. 8 or smaller sieves 2 percent
Asphalt cement 0.25 percent
Temperature of mixing 25 degrees F
PART 3 EXECUTION
3.1 CONTRACTOR QUALITY CONTROL
NOTE: The Contractor may be able to meet the specified quality control requirements
with in house capability or may have to hire a material testing firm to provide
the required quality control testing.
3.1.1 General Requirements
Develop an approved Quality Control Plan. SMA for payment shall not be produced until the quality control plan
has been approved. Address in the plan all elements which affect the quality of the pavement including, but
not limited to:
a. Mix Design and unique JMF identification code.
b. Aggregate Grading.
c. Quality of Materials.
d. Stockpile Management and procedures to prevent contamination.
e. Proportioning.
f. Mixing and Transportation.
g. Mixture Volumetric.
h. Moisture Content of Mixtures.
i. Placing and Finishing.
j. Joints.
k. Compaction.
l. Surface Smoothness.
m. Truck Bed Release Agent
3.1.2 Testing Laboratory
Provide a fully equipped asphalt laboratory, located at the plant or job site, equipped with heating and air
conditioning units to maintain a temperature of 24 degrees C ± 2.3 degrees C 75 degrees F ± 5 degrees F. Laboratory
facilities shall be kept clean and all equipment shall be maintained in proper working condition. The Contracting
Officer shall be permitted unrestricted access to inspect the Contractor's laboratory facility, to witness quality
control activities, and to perform any check testing desired. The Contracting Officer will advise the Contractor
in writing of any noted deficiencies concerning the laboratory facility, equipment, supplies, or testing personnel
and procedures. When the deficiencies are serious enough to adversely affect test results, the incorporation
of the materials into the work shall be suspended immediately and will not be permitted to resume until the deficiencies
are corrected.
3.1.3 Quality Control Testing
Perform all quality control tests applicable to these specifications as set forth in the Quality Control Program.
The testing program shall include, but shall not be limited to, tests for the control of asphalt content, aggregate
gradation, temperatures, aggregate moisture, moisture in the asphalt mixture, laboratory air voids, in-place
density, grade and smoothness. Develop a Quality Control Testing Plan as part of the Quality Control Program.
3.1.3.1 Asphalt Content
A minimum of two tests to determine asphalt content will be performed per lot (a lot is defined in paragraph
QUALITY ASSURANCE) by one of the following methods: extraction method in accordance with ASTM D 2172, Method
A or B, the ignition method in accordance with the ASTM D 6307, or the nuclear method in accordance with ASTM D 4125
, provided that each method is calibrated for the specific mix being used. For the extraction method, the weight
of ash, as described in ASTM D 2172, shall be determined as part of the first extraction test performed at the
beginning of plant production; and as part of every tenth extraction test performed thereafter, for the duration
of plant production. The last weight of ash value obtained shall be used in the calculation of the asphalt content
for the mixture.
3.1.3.2 Gradation and Specific Gravity
Aggregate gradations shall be determined a minimum of twice per lot from mechanical analysis of recovered aggregate
in accordance with ASTM D 5444. When asphalt content is determined by the nuclear method, aggregate gradation
shall be determined from hot bin samples on batch plants, or from the cold feed on drum mix plants. For batch
plants, aggregates shall be tested in accordance with ASTM C 136 using actual batch weights to determine the
combined aggregate gradation of the mixture. The specific gravity of each aggregate size grouping shall be determined
for each 18,000 metric tons 20,000 tons in accordance with ASTM C 127 and ASTM C 128. All samples will be taken
in accordance with ASTM D 75.
3.1.3.3 Temperatures
Check temperatures at least four times per lot, at necessary locations, to determine the temperature at the dryer,
the asphalt cement in the storage tank, the asphalt mixture at the plant, and the asphalt mixture at the job
site.
3.1.3.4 Moisture Contents
Determine the moisture content of aggregate used for production a minimum of once per lot in accordance with
ASTM C 566.
3.1.3.5 Laboratory Air Voids
Take mixture samples at least four times per lot and compact them into specimens, using [50 blows per side with
the hand-held Marshall hammer as described in AI MS-02] [the Superpave Gyratory Compactor as described in AASHTO T 312
]. After compaction, determine the laboratory air voids of each specimen.
3.1.3.6 In-Place Density
Conduct any necessary testing to ensure the specified density is achieved. A nuclear gauge may be used to monitor
pavement density in accordance with ASTM D 2950.
3.1.3.7 Grade and Smoothness
Conduct the necessary checks to ensure the grade and smoothness requirements are met in accordance with paragraphs
PERCENT PAYMENT and QUALITY ASSURANCE.
3.1.3.8 Additional Testing
Any additional testing, which the Contractor deems necessary to control the process, may be performed at the
Contractor's option.
3.1.3.9 QC Monitoring
Submit all QC test results to the Contracting Officer on a daily basis as the tests are performed. The Contracting
Officer reserves the right to monitor any of the Contractor's quality control testing and to perform duplicate
testing as a check to the Contractor's quality control testing.
3.1.4 Sampling
When directed by the Contracting Officer, sample and test any material which appears inconsistent with similar
material being produced, unless such material is voluntarily removed and replaced or deficiencies corrected by
the Contractor. Perform all sampling in accordance with standard procedures specified.
3.1.5 Control Charts
NOTE: If the JMF was designed according to AASHTO M 325, delete the requirements
for plotting stability and flow.
For process control, establish and maintain linear control charts on both individual samples and the running
average of last four samples for the parameters listed in Table 10, as a minimum. These control charts shall
be posted as directed by the Contracting Officer and shall be kept current at all times. The control charts
shall identify the project number, the test parameter being plotted, the individual sample numbers, the Action
and Suspension Limits listed in Table 10 applicable to the test parameter being plotted, and the Contractor's
test results. Target values from the JMF shall also be shown on the control charts as indicators of central
tendency for the cumulative percent passing, asphalt content, and laboratory air voids parameters. When the
test results exceed either applicable Action Limit, take immediate steps to bring the process back in control.
When the test results exceed either applicable Suspension Limit, halt production until the problem is solved.
Use the control charts as part of the process control system for identifying trends so that potential problems
can be corrected before they occur. Decisions concerning mix modifications shall be made based on analysis of
the results provided in the control charts. The Quality Control Plan shall indicate the appropriate action,
which shall be taken to bring the process into control when certain parameters exceed their Action Limits.
Table 10 Action and Suspension Limits for the Parameters to be Plotted on Individual and Running Average Control
Charts
Running Average of
Individual Samples Last Four Samples
Action Suspension Action Suspension
Parameter to be Plotted Limit Limit Limit Limit
4.75 mm sieve, Cumulative Percent 4 5 3 4
Passing, deviation from JMF target;
plus or minus values
0.6 mm sieve, Cumulative Percent 3 4 2 3
Passing, deviation from JMF target;
plus or minus values
Asphalt content, percent deviation 0.4 0.5 0.2 0.3
from JMF target; plus or minus values
Laboratory Air Voids, percent No specific action and suspension
deviation from JMF target value limits set since this parameter is
used to determine percent payment
In-place Mat Density, percent of No specific action and suspension
maximum theoretical density limits set since this parameter is
used to determine percent payment
In-place Joint Density, percent of No specific action and suspension
maximum theoretical density limits set since this parameter is
used to determine percent payment
Table 10 Action and Suspension Limits for the Parameters to be Plotted on Individual and Running Average Control
Charts
Running Average of
Individual Samples Last Four Samples
Action Suspension Action Suspension
Parameter to be Plotted Limit Limit Limit Limit
No. 4 sieve, Cumulative Percent 4 5 3 4
Passing, deviation from JMF target;
plus or minus values
No. 30 sieve, Cumulative Percent 3 4 2 3
Passing, deviation from JMF target;
plus or minus values
Asphalt content, percent deviation 0.4 0.5 0.2 0.3
from JMF target; plus or minus values
Laboratory Air Voids, percent No specific action and suspension
deviation from JMF target value limits set since this parameter is
used to determine percent payment
In-place Mat Density, percent of No specific action and suspension
maximum theoretical density limits set since this parameter is
used to determine percent payment
In-place Joint Density, percent of No specific action and suspension
maximum theoretical density limits set since this parameter is
used to determine percent payment
3.2 PREPARATION OF ASPHALT BINDER MATERIAL
NOTE: For Performance Graded (PG) asphalt cements, insert the plant temperature
range from the Table below into the last sentence of the following paragraph.
Performance Graded Asphalt Plant Mixing Temperatures
Binder Grade Mixing Temp Range (deg F) Mixing Temp Range (deg C)
PG 46-28 240 - 295 115 - 146
PG 46-34 240 - 295 115 - 146
PG 46-40 240 - 295 115 - 146
PG 52-28 240 - 300 115 - 149
PG 52-34 240 - 300 115 - 149
PG 52-40 240 - 300 115 - 149
PG 52-46 240 - 300 115 - 149
PG 58-22 260 - 310 127 - 154
PG 58-28 260 - 310 127 - 154
PG 58-34 260 - 310 127 - 154
PG 64-22 265 - 320 129 - 160
PG 64-28 265 - 320 129 - 160
PG 64-34 265 - 320 129 - 160
PG 67-22 275 - 325 135 - 163
PG 70-22 280 - 330 138 - 166
PG 70-28 275 - 325 135 - 163
PG 76-22 285 - 335 141 - 168
PG 76-28 280 - 330 138 - 166
PG 82-22 290 - 340 143 - 171
A continuous supply of the asphalt cement material shall be supplied to the mixer at a uniform temperature.
The method of heating shall avoid local overheating of the asphalt cement material. The temperature of unmodified
asphalts shall be no more than 160 degrees C 325 degrees F when added to the aggregates. Performance-Graded
(PG) asphalts shall be within the temperature range of [_____] to [_____] degrees C F when added to the aggregates.
3.3 PREPARATION OF MINERAL AGGREGATE
The aggregate for the mixture shall be heated and dried prior to mixing. No damage shall occur to the aggregates
due to the maximum temperature and rate of heating used. The temperature of the aggregate and mineral filler
shall not exceed 175 degrees C 350 degrees F when the asphalt cement is added. The temperature shall not be
lower than is required to obtain complete coating and uniform distribution on the aggregate particles and to
provide a mixture of satisfactory workability.
3.4 PREPARATION OF STONE MATRIX ASPHALT MIXTURE
The aggregates, stabilizer, and the asphalt cement shall be weighed or metered and introduced into the mixer
in the amount specified by the JMF. The combined materials shall be mixed until the aggregate and stabilizer
obtain a uniform coating of asphalt binder and are thoroughly distributed throughout the mixture. Wet mixing
time shall be the shortest time that will produce a satisfactory mixture, but not less than 35 seconds for batch
plants. The wet mixing time for all plants shall be established by the Contractor, based on the procedure for
determining the percentage of coated particles described in ASTM D 2489/D 2489M, for each individual plant and
for each type of aggregate used. The wet mixing time will be set to achieve a minimum of 95 percent coated particles.
The moisture content of all SMA upon discharge from the plant shall not exceed 0.5 percent by total weight of
mixture as measured by ASTM C 566.
3.5 PREPARATION OF THE UNDERLYING SURFACE
NOTE: A SMA is used as a wearing or surface course overlying a conventional
hot-mixed asphalt (HMA). The existing HMA should be cleaned and tack-coated
before placing the SMA. Tack coat materials and procedures will need to be
addressed in the contract documents. See Section 32 12 10 BITUMINOUS TACK AND
PRIME COATS.
Immediately before placing the SMA, the underlying course shall be cleaned of dust and debris. A tack coat shall
be applied in accordance with the contract specifications.
3.6 TEST SECTION
Before full production, place a test section for each JMF used. Construct a minimum test section of [75] [150]
meters [250] [500] feet long and two paver passes wide placed in two lanes, with a longitudinal cold joint.
The test section shall be of the same depth as the course which it represents. The underlying grade or pavement
structure, upon which the test section is to be constructed, shall be the same as the remainder of the course
represented by the test section. The equipment used in construction of the test section shall be the same equipment
to be used on the remainder of the course represented by the test section. Place the test section as part of
the project pavement if approved by the Contracting Officer.
3.6.1 Sampling and Testing for Test Section
NOTE: Table 11 applies only to the test section. The limits in Tables 8, 9,
and 10, apply to a number of tests run from a lot. This is why the limits listed
in Table 11 are different from those listed in Tables 8, 9, and 10.
One random sample shall be taken at the plant, triplicate specimens compacted, and tested for density and laboratory
air voids. A portion of the same sample shall be tested for aggregate gradation and asphalt content. Four randomly
selected cores shall be taken from the finished pavement mat, and four from the longitudinal joint, and tested
for density. Random sampling shall be in accordance with procedures contained in ASTM D 3665. The test results
shall be within the tolerances shown in Table 11 for work to continue. If all test results meet the specified
requirements, the test section shall remain as part of the project pavement. If test results exceed the tolerances
shown, the test section shall be removed and replaced at no cost to the Government and another test section shall
be constructed.
3.6.2 Additional Test Sections
If the initial test section should prove to be unacceptable, make the necessary adjustments to the JMF, plant
operation, placing procedures, and/or rolling procedures. A second test section shall then be placed. Additional
test sections, as required, shall be constructed and evaluated for conformance to the specifications. Full production
shall not begin until an acceptable section has been constructed and accepted.
3.7 TESTING LABORATORY
NOTE: Include bracketed sentence for Corps-managed projects.
The laboratories used to develop the JMF, Perform CQC testing, and for Government acceptance testing shall meet
the requirements of ASTM D 3666. [The Government will inspect the laboratory equipment and test procedures prior
to the start of hot-mix operations for conformance with ASTM D 3666. The laboratory shall maintain this validation
for the duration of the project.] A certification stating that it meets these requirements or clearly listing
all deficiencies shall be signed by the manager of the laboratory and submitted to the Contracting Officer prior
to the start of construction. The certification shall contain as a minimum:
a. Qualifications of personnel: laboratory manager, supervising technician, and testing technicians.
b. A listing of equipment to be used in developing the job mix.
c. A copy of the laboratory's quality control system.
d. Evidence of participation in the AASHTO Materials Reference Laboratory (AMRL) program.
Table 11 Material and Mixture Proportions for Test Section
Property Specification Limit
Aggregate Gradation-Percent Passing
(Individual Test Result)
4.75 mm and larger JMF ± 5.0
2.36 mm and smaller JMF ± 3.0
Asphalt Content, Percent (Individual Test Result) JMF ± 0.5
Laboratory Air Voids, Percent (Average of 3 specimens) JMF ± 1.0
VMA, Percent (Average of 3 specimens) 17.0 minimum
Mat Density, Percent of Maximum Theoretical
Density (Average of 4 Random Cores) 92.0 - 96.0
Joint Density, Percent of Maximum Theoretical
Density (Average of 4 Random Cores) 90.5 - 92.5
3.8 TRANSPORTING AND PLACING
3.8.1 Transporting
NOTE: A material transfer vehicle has been shown to provide a pavement with
improved smoothness and less segregation. A material transfer vehicle is required
when doing runway construction. Remove last sentence if material transfer vehicle
is not used.
Transport the SMA from the mixing plant to the site in clean, tight vehicles. Schedule deliveries so that placing
and compacting of mixture is uniform with minimum stopping and starting of the paver. Provide adequate artificial
lighting for night placements. Hauling over freshly placed material will not be permitted until the material
has been compacted as specified, and allowed to cool to 60 degrees C 140 degrees F. To deliver mix to the paver,
use a material transfer vehicle which is operated to produce continuous forward motion of the paver.
3.8.2 Placing
Place and compact the mix at a temperature suitable for obtaining density, surface smoothness, and other specified
requirements. Upon arrival, the mixture shall be placed to the full width by an asphalt paver; it shall be struck
off in a uniform layer of such depth that, when the work is completed, it shall have the required thickness and
conform to the grade and contour indicated. The speed of the paver shall be regulated to eliminate pulling and
tearing of the asphalt mat. Unless otherwise permitted, placement of the mixture shall begin along the centerline
of a crowned section or on the high side of areas with a one-way slope. The mixture shall be placed in consecutive
adjacent strips having a minimum width of 3 meters [10 feet]. The longitudinal joint of the SMA course shall
be offset from the longitudinal joint in the course immediately below by at least 300 mm 1 foot; however, the
joint in the surface course shall be at the centerline of the pavement. Transverse joints in the SMA course
shall be offset by at least 3 meters 10 feet from transverse joints in the previous course. Transverse joints
in adjacent lanes shall be offset a minimum of 3 meters 10 feet. On isolated areas where irregularities or unavoidable
obstacles make the use of mechanical spreading and finishing equipment impractical, the mixture may be spread
and luted by hand tools.
3.9 COMPACTION OF MIXTURE
After placing, the mixture shall be thoroughly and uniformly compacted by rolling with steel-wheel rollers.
The surface shall be compacted as soon as possible without causing displacement, cracking or shoving. The sequence
of rolling operations and the type of rollers used (with the exception noted) shall be at the discretion of the
Contractor, with the exception that the Contractor shall not apply more than three passes with a vibratory roller
in the vibrating mode. The speed of the roller shall, at all times, be sufficiently slow to avoid displacement
of the hot mixture and be effective in compaction. Any displacement occurring as a result of reversing the direction
of the roller, or from any other cause, shall be corrected at once. Sufficient rollers shall be furnished to
handle the output of the plant. Rolling shall continue until the surface is of uniform texture, true to grade
and cross section, and the required field density is obtained. To prevent adhesion of the mixture to the roller,
the wheels shall be kept properly moistened, but excessive water will not be permitted. In areas not accessible
to the roller, the mixture shall be thoroughly compacted with hand tampers. Any mixture that becomes loose and
broken, mixed with dirt, contains check-cracking, or is in any way defective shall be removed full depth, replaced
with fresh hot mixture and immediately compacted to conform to the surrounding area. This work shall be done
at the Contractor's expense. Skin patching will not be allowed.
3.10 JOINTS
The formation of joints shall be made ensuring a continuous bond between the courses and to obtain the required
density. All joints shall have the same texture as other sections of the course and meet the requirements for
smoothness and grade.
3.10.1 Transverse Joints
The roller shall not pass over the unprotected end of the freshly laid mixture, except when necessary to form
a transverse joint. When necessary to form a transverse joint, it shall be made by means of placing a bulkhead
or by tapering the course. The tapered edge shall be cut back to its full depth and width on a straight line
to expose a vertical face prior to placing the adjacent lane. The cutback material shall be removed from the
project. In both methods, all contact surfaces shall be given a light tack coat of asphalt material before placing
any fresh mixture against the joint.
3.10.2 Longitudinal Joints
Longitudinal joints that are irregular, damaged, uncompacted, cold (less than 80 degrees C 175 degrees F at the
time of placing the adjacent lane), or otherwise defective, shall be cut back a maximum of 75 mm 3 inches from
the edge with a cutting wheel to expose a clean, sound vertical surface for the full depth of the course. All
cutback material shall be removed from the project. All contact surfaces shall be given a light tack coat of
asphalt material prior to placing any fresh mixture against the joint. The Contractor will be allowed to use
an alternate method if it can be demonstrated that density, smoothness, and texture can be met.