A Contractors Update

on Full Depth

Reclamation

FDR

Presented to APWA Annual Conference

Barry McKeon

Technical Manager

Hubbard Construction Company

April 2013

Presentation Outline Introductions / Brief Overview of The Hubbard Group

Common Types of Asphalt Recycling

FDR (Full Depth Recycling)

The Process

The Advantages

CIR (Cold In-Place Recycling)

Equipment Overview

Project Applications

Contractors Quality Control

Economic & Environmental Benefits

Conclusions

Common Types of Roadway Recycling in the

US

Hot Recycling (HR) Hot Mix Asphalt (HMA)

Hot-In-Place Recycling (HIR)

Full Depth Reclamation (FDR)

Cold-In-Place Recycling (CIR)

Cold-In-Plant Recycling (CIP)

The Hubbard Group are Members of the

Asphalt Recycling & Reclaiming Association arra.org

Full Depth Reclamation

FDR

FDR- 6”–12” blend of asphalt and

base materials

Full Depth Reclamation (FDR)

Cold Full-Depth Reclamation (FDR)

Full-Depth Reclamation is an

economical, recycling technique in

which the full flexible (asphalt)

pavement section and a portion of

the underlying base materials are

uniformly pulverized, blended and

then stabilized with a bonding

agent

Typically Utilizes 1.5% - 3.5%

emulsion or foamed asphalt

material as a bonding agent.

Cement can also be used to

enhance bitumen, modify soils to

CBR/LBR or produce Soil Cement

(Rigid Base).

Others- Fly ash, Lime…..

The FDR Process

Advantages

Uses 100% of existing materials – Extremely GREEN process.

Eliminates Cracks and Resists Future Fatigue Cracking.

Much quicker than traditional base reconstruction methods.

Load bearing strength of existing base section can be increased.

More Advantages

Very effective on projects requiring widening.

longitudinal re-profiling and grade correction can be accomplished.

Cross slope corrections can be realized.

Base courses constructed using the FDR process can result in more moisture tolerant base courses.

Moisture Susceptibility

Florida Limerock FDR with 3% emulsion

Cold-In-Place

Recycling

(CIR)

CIR Equipment

CIR: 4”-6”, 100% Asphalt, on well supported base.

Creates new asphalt base layer.

FDR: 6” – 12” blend of asphalt and base material.

Creates new base structure layer.

CIR vs. FDR – “What’s The

Difference?”

Recycled Materials at Auger

Recycled material at Auger before screed, well mixed and well graded material

CIR Finished Surface

Recycled Material Surface Finish / Mix

FDR Equipment Overview

Pulverizing, Injection & Stabilization:

Wirtgen 2500 S Cold Recycler & Stabilizer.

2 Pumps with 2 Spray Bars – 1 for emulsion (or water) & 1 for foam.

Capable of Cold FDR with Emulsion or Foam injection.

Drum width = 8’

Cutting Depth: Up to 20” depth.

TEREX Reclaimer

Cutting & Injection

No Cross Mixing

Transferring & Monitoring Materials

Steering Considerations

Recycling Train

2009/10 FDR Field

Application

County Road 609

Martin County, Florida

Existing Roadway Conditions

Initial Pulverization & Widening

Widening Trench

Shaping & Compacting

Elevation Changes Required by

Plans

18”

Injection of Emulsion

Existing Material with 2% Emulsion

Injected

Final Grading & Compaction

Primed FDR with Temporary Stripes

2.5” Superpave HMA Overlay

Other overlay options for rural applications:

- Double Chip Seal

- Cape Seal

- Micro-surfacing

Average recycling speed for the

project 27.5 ft/min.

This average speed at a depth

of 6 ins and a width of 12.5ft

equates to an hourly recycling

tonnage of 610 tons per hours.

Application & Production

Average Depth: 7”

Emulsion Content = 2%

Daily average production:

Pulverization -8,000 SY / Day *

Emulsion Injection – 5,000 SY / Day

All materials were metered electronically by the machine.

* 2 WR 2500’s in Tandem

FDR Project Overview – CR 609 in Martin

County

Total Contract Price:

$2,117,145.96

Length: 9.2 Miles (18.4 Lane

Miles)

Completion Time: 60 Days

Bumby Avenue Full Depth

Reclamation Project

City of Orlando, Florida

Bumby Ave. Project Description

Heavily traveled urban roadway on the east side of Downtown Orlando

Approximately 4,800’ long x 60’ wide (5 Lanes) = 32,000 Square Yards

18,000 square yards existing soil cement base

14,000 square yards existing lime rock base

Curb and gutter & utilities throughout project

Work to be performed in 9 phases due to City’s concerns:

Impact on businesses

Experience with previous contractors

Contract time = 180 Calendar Days

All work performed during normal business (daylight) hours

Project

Location

Description of Work:

Pulverize 11” of existing base and pavement

Remove 3” of material from site

Inject remaining 8” with emulsion

Grade new materials to 2% cross slope matching curb & utilities

Prime and sand new base

Allow 48-hour cure

Overlay with 3” SuperPave Hot Mix Asphalt

2” 12.5 TL-C structure course

1” 9.5 TL-C surface course

New pavement markings

Completion of FDR & HMA Work

Bumby Avenue, City of Orlando

Contract time allowed 180 Calendar

Days

All structural asphalt completed 83

Calendar Days / 51 Working Days

Plymouth Ave.

20,146 Square Yards

High Traffic Volume

Asphalt from 8” to 2”

Base Materials – Lime Rock

and Snail Shell

2 Mix Designs

Soil Cement

Volusia County 2012

Carlton Avenue

Douglas Avenue

Forest Avenue

Howry Avenue

Volusia County

5,756 Sys Total – Residential Area

Low Traffic Volume

Stevens Avenue

3,200 Sys – Residential Area

Low Traffic Volume Asphalt Thickness: 1.5” to 2.5”

Cement Spread Rate: 15lb/SY

Base Material: Clayey Sand

RMI Cement Spreader

Volusia County Projects

2012

Minnesota

Avenue

Volusia County 6 Foot Widening

Excess Lime Rock Material

from Plymouth

Blended into Existing Base Asphalt Thickness: 1.5” to 2.5”

Cement Spread Rate: 15lb/SY

Base Material: Clayey Sand

Uniform across new 22’

width

Minnesota Ave

Before and After

Minnesota

Avenue

Downtown Tampa

Cores and Mixer Sample

Good base under very thin asphalt did not require any additive.

Desoto Memorial Hospital

Before

Resurfaced with Double Chip and Cape Seal

Pre-Mixing and Re-Grading

Cement Spread

Mixing and Compacting

Checking Gradation of Pre-Mixed

Materials

LBR Samples

Roadway Surfaces Favorable For In-Place

Recycling

Block Cracking

Caused by insufficient asphalt thickness,

weak structural base, heavy traffic & aging

roadway

Minor Rutting

Caused by insufficient thickness of asphalt,

poor asphalt mix design formulation,

improper compaction methods or heavy

traffic

Major Rutting

Caused by very heavy traffic conditions,

deficient structural capacity, deficient

compaction or deficient drainage conditions

Block Cracking Minor Ruts

Major Ruts Ravelin

g

Materials and Mix Design

Marshall Stability Tensile Strength

Specifications & References for Mix Design Procedures

The Wirtgen Cold Recycling Manual

Published in many languages &

utilized all over the world.

Other Primary References:

ARRA Basic Asphalt Recycling

Manual

Asphalt Institute – Asphalt Cold Mix

Manuals (MS 14 and MS 19)

PCA Soil Cement Laboratory

Handbook

Mix Design Methods for FDR

Laboratory Mix Design Methodology:

Steps Required for Mix Design Development:

Cut cores or exploration windows to obtain representative materials

Pulverized materials for gradation characterization

Binder selection (emulsion or foam usually required by contract

specifications)

Determine optimun water content

Determine optimun asphalt binder determination

Determine optimun cement/lime binder content (if needed)

71

Sampling

Obtaining Materials for Design

Requirements

Perform enough cores to

determine if variables exists

Depending on size of area &

known base types, cut or mill

windows to obtain

representative samples needed

to prepare mix design(s)

Documentation of Existing Roadway

Conditions

Existing Asphalt Ranged

From 2.5” to 6” deep.

Avg Depth = 4.5”

Mix Design Considerations

Mix Design Methods

Modified Marshall Stability (Asphalt Inst. or ARRA)

Tensile Strength (Wirtgen)

Compressive Strength

(Soil Cement) (PCA)

CBR/LBR (AASHTO/FDOT)

(Cement Modified)

Laboratory Mix Design Methodology

Binder Options In-Place Recycling Processes:

Asphalt binders

Asphalt emulsion (CSS-1, CSS-1H, SS-1 et CMS-

2)

Foamed asphalt (usual grade without silicone )

Hydraulics agents

Cement

Hydrated lime

Composites binders

Asphalt emulsion + Cement

Asphalt emulsion + Hydrated lime

Foamed asphalt + Cement

Foamed asphalt + Hydrated lime

Pre-Bid Information

Client Provided Core Information

Client Provided Mix Design Criteria

Client Provided Additive Pay Items

Client Provided Contractor Quality Control Requirements

Quality Control Best

Practices for Full Depth

Reclamation

Barry McKeon, Technical Director

RMI/Hubbard Construction Company

Contractor Project Specific QC

Plan Description of process i.e.…FDR

Project Assessment and Site Investigation

Sampling and Mix Design

Mixing Equipment and Mixing Operations

Spreading Finishing and Compacting

Priming and Curing

Quality Control

Speedy Moisture Content

Early verification of

moisture content

Monitor throughout the

operation and adjust as

needed

Moisture content by nuclear gauge can not be used when RAP is present

Quality Control During Field Operations

? Why is Moisture Content Important?

2 Reasons

Coating and Compaction

Pre Mixing for Widening or Cross Slope

adjustments

Sampling Full Depth of Mixture

Check for Depth

Uniformity

Gradation

Maximum

Size (95% pass

2”)

Samples for

Check Cross Slopes

Compaction

Nuclear Density Tests

Establish Control

Strip

Wet Density

96% Min

Prime and Cure

Always apply

Bituminous Prime

Protects base from

weather

Holds better under traffic

Provides bond to new

surfacing (HMA, Chip,

Micro)

Cure Time to Reduce

Environmental Advantages of In-Place Recycling

Methods

Removal of trucks hauling materials to and from the project greatly reduces

congestion associated with traditional road rehabilitation projects.

Shorter construction duration & reduced equipment requirements enhance

project efficiencies & reduce fuel and energy consumption at the project site.

Elimination of the energy inputs in the manufacturing process of producing

aggregates and hot mix asphalt.

Reduction of Greenhouse Gas Emissions .

Besides the advantages to the environment, agencies also realize significant

cost savings of at least 30% associated with reduced equipment,

transportation, and labor costs

Conservation of Natural Resources & Energy

Agencies are look into more “green strategies” FHWA “Think Recycle First

and Always”

FDR offers the ideal sustainable strategies since they utilize 100% of existing

materials and require up to 80% less energy per ton as compared to hot mix

overlays, or conventional construction.

These numbers are greatly significant when designers are evaluating a

sustainable strategy for a project.

Thus, in-place processes not only provide a sustainable strategy but they also

provide a pavement section at a lower initial cost.

Reduction of Energy Use

.

The energy expended for both the traditional

Hot Mix Asphalt process, and the proposed

CIR technology.

Summary & Conclusions:

Both FDR & CIR are FHWA approved processes that have been successfully

utilized around the globe for about 15-20 years.

Environmentally, the use of the in-place recycling processes on local projects

would reduce the consumption of significant natural resources & savings

could allow for funding of additional miles of roadway maintenance.

The use of in-place recycling processes has the potential to significantly

reduce the time required to complete local reconstruction projects, while

minimizing inconvenience to the public.

Would you like additional information?

The Asphalt Recycling & Reclaiming

Association (ARRA) is a great

resource for additional information

related to CIR & Full Depth

Reclamation:

Website:

www.arra.org

Thank You Very

Much!