COLD IN-PLACE RECYCLING

Dennis McElroy - CIR Operations Manager

Specification & Research Papers

Overview

What is CIR?

When to use CIR and the Benefits

CIR Basics/Misc info

Order of Operations

Project Examples

“It is a beautiful thing when the Green Solution is also

the most cost effective one.”

Michael J. Murdter, P.E., Director County of Santa

Clara Roads and Airports Department

What is Cold In-Place Recyling (CIR)?

CIR is the processing and treatment with bitimious

and/or chemical additives of existing HMA

pavements without heating to produce a restored

pavement layer.

Wirtgen – 3800

“Single Unit Recycler”

CIR – Foamed Asphalt

“Welded or Bonded Product”

Oil Pump and Control Unit 12.5’ Down Cutting

Milling Drum

Microprocessor/Computer to

control Oil Percentage and

water delivery

Rear Tamping Screed

Or pickup machine

and paver

CIR – Depths

CIR – Foam

Depth: 3”minimum – 6” maximum

AC, AB, AC/AB blends

Eliminating the potential for reflective cracking = lowers costs in the long run on your Pavement Maintenance System

Typical AC/AB Section Typical AC/CIR/AB

Section

CIR (Foam) – How the mixing Chamber works

12.5’ (fixed)

Down Cutting

Drum

CIR Basics – How it Works

Bitumen (Oil)

PG 64-10 at 170 C

+ Water = Foam

Range 2% - 2.5%

Cement

Portland Type II

Range 1% - 1.5%

When to use it?

Bridging the gap between Maintenance Methods and Complete Reconstruction.

Alternate Method to:

Thick Overlays

Remove and Replace

Over 25% Digouts

Average Production Rates

Urban Environments:

50,000 SF – 70,000

SF per shift

Rural Environments:

65,000 – 130,000 SF

per shift

= 1 – 2 lane miles per shift

= Approximately 30 - 50% reduction in

construction times for the pavement rehabilitation

portion of the project

Benefit: Cost/Trucking/Emissions Savings

Reducing off haul costs/materials associated with conventional Remove and Replace

Emissions Savings from trucking, hot plants, and additional equipment needed during R&R – Environmentally Friendly

Benefit: Lowers User Delays

Immediate access for

pedestrians, vehicles,

driveway access, and

emergency personnel

safe and convenient.

Cold material, wont

pick up on car tires.

Benefit: Lowers User Delays

CIR- Foam (Night Work Acceptable)

Cost Savings (20% - 40%)

An example comparison between conventional rehabilitation with overlay and CIR with foamed asphalt for a project (Catamaran Street, Foster City with 149,600 ft2 paved surface area):

Conventional Rehabilitation:

32,000 ft2 of existing asphalt concrete repair= $176,000

3” asphalt concrete overlay= $252,824

Total = $428,824 (would’ve taken 5 days to complete).

CIR-foam:

4” CIR with foamed asphalt = $157,080

2” asphalt concrete overlay = $171,666

Total = $328,746 (took about 2 days to complete).

This project was bid using conventional methods and Value Engineered delivering a Net saving through using CIR-foam=$100,078 (~23%) while eliminating 3 days of traffic closures.

Where can you CIR?

Collector Roads County Rural Roads Major Arterials

Universities Residential

Order of Work

Preliminary Investigation:

(1) Conduct visual pavement inspection and coring

(2) Perform sampling of existing roadway materials to account for changes in the pavement, and

(3) perform mix design in the laboratory.

Order of Work

Public Notifications

Lower all existing utilities +/- 3” below CIR depth

Wedge Cut / Conforms/ Milling

Trim outside edge of roadway to make room for overlay or other surface treatment

Address Severe Base Failures at this time.

CIR - The Process

Cement spreading- The

cement spreader

is usually ahead of the

equipment train by

about 50 ft spreading

cement over a pre-

dampened pavement

surface, at an average

rate of about 1% by weight

of RAP.

CIR - The Process

During CIR Activities

Single Lane Closure

Pulverize/Process/

Place/Compact

Existing Materials

12.5’ (fixed) Down

Cutting Drum

CIR – The Process

Water Truck with Paver

CIR – The Process

Material is compacted

to a minimum of 98%

using two (2) 12 – ton,

steel drum vibratory

rollers

A 12 – ton pneumatic

(rubber tire) roller is

used to finish the surface

and prepare it for

traffic.

CIR - The Process

Apply Fog Seal (SS1 cut 50/50), Temp Striping, Sand Blotter to treated Surface

Reconstructed Roadway is ready to surface in 2-3 days after initial cure period

No Deflection or Rutting, No Supplemental Compaction

OPEN TO TRAFFIC IMMEDIATELY

Fog Seal Sand Blotter

Example: Monterey Rd., San Jose (2011) Project Specifications

638,040 Sf

Conventional R&R

3” Mill

6” Digouts

Leveling Course / R-HMA Overlay

Total: $2,540,470.00

Cold In-Place Recycling

2” Wedge Cut

Minimal 6” Digouts (Areas

innaccessbible)

4” CIR – EAM (Foam)

2” RHMA Overlay

Total: $2,122,400.00

NET SAVINGS: 16% or $418,070.00

Monterey Rd., San Jose

Existing Pavement Conditions

Alligator Cracked Surface

Years of patching

Raveling/Potholes

Aged Oxidized Pavement

Type II Slurry Seal

Areas of Petro mat

Benefits

Elimination of costs for 780 truckloads of importing and off haul costs of over 15,600 tons of aggregates to and from landfill and/or asphalt plant or quarry.

Conventional R&R method would have taken approximately 18 days, whereas the CIR method took only 9 days.

BEFORE

FINAL CIR SURFACE

Monterey Rd., San Jose

Skid Marks on final CIR

Surface – No Raveling

Foamed CIR

Monterey Rd. Photos Taken on 3/22/2016

R-HMA Overlay was placed in the intersection (without an underlying CIR layer) and it is already showing signs of fatigue, cracking, early failures.

4” CIR – Foam w/ Leveling Course & R-

HMA Overlay Section

Holsclaw Rd – Santa Clara County

Constructed - Sept. 2011

Holsclaw Rd (Leavesley Rd – Gilman Rd, Gilroy CA)

Santa Clara County

6,000’ x 24’ = 144,000 SF Recycled using Foamed Asphalt

X2 Shifts (72,000 SF per Shift)

+/- 3” – 3.5” CIR layer using Foamed Asphalt

Chip Seal wearing course x1 (2’x2’) pothole/driveway scuffed

Pg. 10

x4 small locations chip seal worn, subgrade problems

Pg. 11

Holsclaw Rd – Before

May – 2011 Photo Taken off of

google Earth

Photo Taken 1-2-2013

Photo Taken 3-22-2016

Beginning of CIR Section at Leavesley Rd

3-22-2016

Beginning of CIR Section at Gilman Rd

3-22-2016

Skid marks – CIR layer still intact

Adjusted Utilities – No Settling

Consistent throughout the entire project

CIR Joint

CIR Layer

OLD AC Section, road was

reconstructed with (2) 12’

passes off of centerline.

No shoulder backing was

spec’d by the county

- No separation at the joint

Photo Taken 1-2-2013 Photo Taken 3-22-2016

Scuffed driveway entrance to farm

(1) HMA patched

pothole (2’ x 2’)

(1) location approx 30’

long in the SB lane with

4 small areas where the

chip seal has started to

wear and expose CIR

layer to elements. Soft

subgrade may also be

an issue here.

Note: Sharp Turn,

shaded by trees

Gilman Rd

(Chip Seal placed on top of existing pavement Sept 2011 – NO CIR)

Photo Taken 1-2-2013 Photo Taken 3-22-2016

Gilman Rd – Chip Seal Only

Final –Other Considerations

Work Hour Windows – Need to be

minimum 8 hrs. to be cost effective

Temperature: 50 degrees and rising

Widths outside of 12’ require a

supplemental milling machine

Recommend a discussion with a

contractor during the design

phase

Surface Layer is necessary

HMA / R-HMA Overlay

Chip Seals / Cape Seals in specific

areas

Questions and Answers

Dennis McElroy

CIR Operations Manager

Cell: 408-639-8063

dmcelroy@graniterock.com