Earthwork

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

LOTs

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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

Reclaimed Asphalt Pavement (RAP)

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◦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

RAP is allowed:

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Pipe Zones 125-8.3

Bedding Zone 4” below the pipe (Can be 12” when backfilling for removal of rocks or other hard material

PIPE

Top Zone - Up to the subgrade or final grade

CoverZone

1 foot above pipe

Lowest Zone

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Base or final grade

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

125 – Pipe Backfill Density – Effictive July 13

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100% Density in Cover Zone and Top Zone

Bedding Zone

PIPE

Top of pipe to bottom of base < 15 inches

CoverZone

Lowest ZoneBottom ofTrench

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Base or Pavement

Top ZoneTop Zone Minimum Density

=100% Std. Proctor

95% Density in Cover Zone

Bedding Zone

PIPE

Top of pipe to bottom of base >= 15 inches

CoverZone

Lowest ZoneBottom ofTrench

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Base or Pavement

Top Zone Minimum Density =100% Std. Proctor

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

125 – Pipe and Structure compacted in one operation

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.

Max. Lift Thickness

Requirements for max. 12 inch thick compacted Earthwork

Section Embankment 120-8.2

Pipe Backfill125-8.1

A-3 and A-2-4 soils with up to 15% fines

No Test strip required Test strip required

12 inch compacted lifts are only

allowed above the soil envelope

A-1, Plastic materials, and A-2-4 Materials with greater than 15% fines

Test strip required

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Trench Box Construction

How many passing density tests are required before the contract allows Reduced Frequency Density Testing for:

Pipe backfill?

Embankment?

Reduced Frequency Testing

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* For projects let after July 2014 Reduced frequency for pipe backfill in the trench box is reduced to one per four LOTs

Reduced Frequency in Pipe Backfill and Embankment Roadway Pipe Backfill

# of passing tests required before Reduced Frequency can be considered

12 6

Reduced Test Frequency 1 per 2 LOTs

1 per 2

LOTs*Required to use the same compactive effort on the untested LOTs as the LOT that is tested

Yes Yes

Select test locations randomly from one of the two (or four) LOTs under consideration

Yes Yes

Requires Engineers permission to place more than one LOT over an untested LOT

Yes Yes

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)

Stabilization Materials

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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. 

RAP or RAP Blend Stabilizing Material

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

RAP as a Stabilization Material

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◦ 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

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RAP or RAP Blend Stabilizing Material

RAP or RAP Blend

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

Accept Material

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

Asphalt Content <= 4.7%

Remove Material

Yes

No

Decide if the material is RAP/RAP Blended material (Jump to Step 2) or treat as Local Material (clay)

Yes

No

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

Review the plan with the District Materials Engineer.

Prepare stockpiles for materials testing

Existing Rock 200-2.2

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.

Existing Rock 200-2.2

Retaining Wall Systems

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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.

LOT Definition for Retaining Wall Systems

Changes to 548

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.

More LOT details

http://www.dot.state.fl.us/construction/CONSTADM/Guidelist/InspectGuidelist/FY1213/MSE-Wall-Inspectors-Handbook.pdf

Changes to 548

Example

Straps

3 foot zone

6’ max between straps

500’

• 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?

150’80’

270’380’

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

548-8.5.2 Flowable Fill: ◦Metallic wall components must be completely

encapsulated by the flowable fill.

Optional Materials for Wall Backfill

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

Optional Materials

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.

Optional Acceptance for backfill

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

Filter fabric – Changes Jan 15

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.

Excerpt from FM 1-T267

A4

Clay as Stabilizer

Step 1: SourceSample 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

Continue to meet acceptance criteria

in 160-4

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

Reject source

Pass

Remove Stabilizing Material

No

Yes

No

Yes