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120-8.1 Embankment Construction – LOTs
What is the maximum length of a LOT?
• Mainline pavement lanes, turn lanes, ramps,
parking lots, concrete box culverts and retaining
wall systems
• A LOT is defined as a single lift of finished embankment
not to exceed 500 feet.
• Shoulder-Only areas, bike/shared use paths, and
sidewalk areas
• A LOT is defined as 2000 feet or one Day’s Production,
whichever is greater. Effective July 14
1-2

Where is RAP prohibited?
◦ Construction areas that are below the
seasonal high groundwater table
elevation.
◦ Behind and below MSE Wall backfill.
◦ Base Material other than on Shoulders
1-3
◦ Embankment above the water table
 Soil & RAP mixture120-8.4.2
 Not allowed in the upper 12 inches of
Embankment
 Alternate Layer Construction 120-8.4.3
◦ Shoulder Base 283
◦ Stabilizing Material 160
1-4
Base or final grade
Top Zone - Up to the subgrade or final grade
Soil Envelope
(No Thick Lift)
1 foot above pipe
Cover
Zone
PIPE
Bedding Zone 4” below the pipe (Can be 12” when
backfilling for removal of rocks or other hard material
Lowest Zone
1-5
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Compaction requirements are the same for both
Concrete and Metal Pipe
Top of pipe is less than 15 inches below base
◦ 100% standard proctor within cover zone

Top of pipe is greater than 15 inches below base
◦ 95% standard proctor within cover zone

Structure backfill requires 100% of Standard
proctor regardless of the depth
1-6
Base or Pavement
Soil Envelope
(No Thick Lift)
Top Zone Minimum Density
=100% Std. Proctor
Top Zone
Cover
Zone
Top of pipe to bottom
of base < 15 inches
PIPE
Bedding Zone
Bottom of
Trench
Lowest Zone
1-7
Base or Pavement
Soil Envelope
(No Thick Lift)
Top Zone Minimum Density
=100% Std. Proctor
Cover
Zone
Top of pipe to bottom
of base >= 15 inches
PIPE
Bedding Zone
Bottom of
Trench
Lowest Zone
1-8
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125-8.1.1 states “Backfill for structures and pipe
compacted in one operation will be considered as
one LOT within the cover zone”
Drainage structures require 100% density
regardless of the depth.
If pipe and structure are compacted in one
operation one density test that meets 100%
density may represent both pipe and structure.
◦ Density tests must be taken at random locations along
Structure and pipe
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Test Strip Requirements for 12 inch thick compacted lifts.
125-8.1.6 – In the soil envelope - maximum allowed thickness of backfill is 6
inches.
Requirements for max. 12 inch thick compacted
Earthwork
Section
A-3 and A-2-4
soils with up to
15% fines
A-1, Plastic
materials, and A-24 Materials with
greater than 15%
fines
Embankment
120-8.2
Pipe Backfill
125-8.1
No Test strip
required
Test strip required
Test strip required
12 inch compacted
lifts are only
allowed above the
soil envelope
110

How many passing density tests are required
before the contract allows Reduced Frequency
Density Testing for:

Pipe backfill?

Embankment?
112
Reduced Frequency in Pipe Backfill and Embankment
Roadway
Pipe
Backfill
# of passing tests required before Reduced Frequency can 12
be considered
6
Reduced Test Frequency
1 per 2
LOTs
1 per 2
Yes
Yes
Select test locations randomly from one of the two (or four) Yes
LOTs under consideration
Yes
Requires Engineers permission to place more than one
LOT over an untested LOT
Yes
Required to use the same compactive effort on the
untested LOTs as the LOT that is tested
Yes
* For projects let after July 2014 Reduced
frequency for pipe backfill in the trench box is
reduced to one per four LOTs
*
LOTs
 Commercial Material - Approved Source
(usually Aggregate Base) 160-2.1
 Existing Base 160-2.3
 Local Materials 160-2.2 (Local Materials as
defined in 914)
114

What is the most recycled material in the United
States?
According to the EPA asphalt pavement is the most recycled
product in the United States by weight.
 Local Materials 160-2.2 (Local Materials
as defined in 914)
 Acceptance requires:
 Source investigation Material ID 440A
 Sample & test from the roadway for
material acceptance 160-3.2.1
Material ID 440B
119
◦ Source Investigation (440A)
 Evaluate the stockpile as a local material - 160-2.2
 If failing organic content is due to the asphalt content of RAP or RAP
Blended material the department may modify acceptance at the
roadway
 Modified Acceptance for RAP or RAP Blend (440/440B)
 Sample and test for Asphalt Content (FM 5-563) after Mixing
 The upper limit for FM 5-563 in the mixed Subgrade is 4.7%
 Failure may indicate too much Asphalt or the presence of a
material with a high organic content
120
RAP or
RAP
Blend
Decide if the material is RAP/RAP
Blended material (Jump to Step 2)
or treat as Local Material (clay)
Yes
Step 1: Source Sampling / Engineer
inspection: (i.e. stockpiles, plant
millings). Sample and test 440A
comparing results to Section 914.
QC/VT collect 3 separate pint
samples and test for OC, LL/& PI.
Test for T27 if necessary
Step 2: Field Testing: If the
RAP or RAP Blended material
is uncontaminated, acceptance
may be based on Asphalt
Content by ignition oven (FM
5-563) after mixing.
Pass
Remove Material
No
No
Asphalt
Content
<= 4.7%
Accept
Material
Yes
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Requires a “Process Control Plan” from the
Contractor including
◦ Location of the existing rock and where it will be used.
◦ Methods of handling the rock
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Review the plan with the District Materials
Engineer.
Prepare stockpiles for materials testing

QC and District Materials Office each collect 3
samples for materials testing.
◦ All tests must meet the material requirements for the
base

If 10 consecutive LBR tests are greater than 120
and no individual test is less than 120 the
sampling requirements may be reduced to one
sample per stockpile.
124

A LOT is defined as a single lift of finished
embankment not to exceed 500 feet in length or
cumulative length of continuous, interconnected
walls.

Backfill within 3 feet from the panels and backfill
beyond 3 feet from the panels are separate LOTs.

Strips up to 8 feet wide between two retaining wall
volumes constructed with the same material in one
operation may be considered as one LOT with the
retaining wall volumes.

Overlapping retaining wall volumes may be
considered one LOT, excluding the 3 feet width
behind the panels.
500’
150’
80’
6’ max between straps
3 foot zone
380’
270’
•The contractor places this area in one lift and compacts in each
zone in one operation. What is the minimum number of Density
tests for one lift in this scenario?
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548-2.6.4 Coarse Aggregate Backfill:
◦ Use Size 57 to 89 (unless restricted in the plans
◦ Must test aggregate for pH, resistivity, sulfate, and
chloride content – Effective July 14
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548-8.5.2 Flowable Fill:
◦ Metallic wall components must be completely
encapsulated by the flowable fill.

548-8.5.1 Compacted Select and Coarse
Aggregate Backfill:
◦ Within 3 feet of wall
 Equipment must weight at least 600 lbs and less than 1000
lbs.
 Minimum three passes
◦ Greater than 3 feet away from wall
 Requires vibratory compaction with centrifugal force >= 7500
lbs.
 Minimum two passes

548-9.4.1 Optional Acceptance Criteria for A-3
and A-2-4 Materials: Obtain a minimum density
of 95% of the maximum dry density as determined
by AASHTO T99 within 3 feet behind the wall face
and obtain a minimum density of 100% of the
maximum dry density as determined by AASHTO
T99 beyond 3 feet behind the wall face.
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Beneath rip rap, pipe wrap, MSE Wall Joints,
Ditch Lining
The material properties have been removed from
Design Standard 199 and added to specification
985.
Allowable materials will be listed in the QPL
Will still require a submittal to State Materials
Office
Appendix
A3

2. When testing other materials from the roadway for
project acceptance a sample is made up of three
subsamples:
◦ a. Replace the word “sample” with “subsample” in
AASHTO T 267.
◦ b. Randomly select a location along the roadway and collect three
subsamples across the roadway. When collecting a subsample,
sample the full depth of the lift taking care to exclude any
underlying material.
◦ c. In the laboratory, perform loss on ignition for each subsample.
Record the individual results. Determine individual maximum and
average organic content for the subsamples collected in (b). If
required, the remaining material may be combined for other
testing.
A4
Clay as
Stabilizer
Reject source
No
Step 1: Source
Sample and test the source (440A).
Compare results to 914. QC/VT
collect 3 separate pint samples and
test for OC and LL/PI. Sample and
test for T27 if necessary
Pass
Yes
Remove Stabilizing
Material
No
Step 2: Material at the roadway (After spreading
and before mixing) Sample and test 440B
meeting the frequency of section 160-3.4. Take 3
1 pint samples across the road at a random
location and test for OC and LL/PI. Sample and
test for T27 if necessary (rocks > 3 ½ inch)
Pass
Yes
Continue to meet
acceptance criteria
in 160-4