welcome apwa 2015northernca.apwa.net/content/chapters/northernca... · distressed pavements...

All Data & analysis courtesy of John Bryce of Harris & Associates

WELCOME APWA 2015

Dennis Rogers, TensarPavement Maintenance Manager, West

How Best to Protect Asphalt Overlays with Interlayers -

Delay Deterioration and

Extend Pavement Life

11-18-15

All Data & analysis courtesy of John Bryce of Harris & Associates

Pavement Optimization

Embankment StabilizationReinforced Slopes

Retaining Walls

Subgrade Stabilization & Pavement Optimization

Erosion Control

Geosynthetics Used in Construction

Distressed Pavements

Pavement Deterioration

Deteriorating Forces

Pavement Deterioration

1. Water intrusion

2. Crack Forces

Base

3.Traffic Loading

4.Thermal Movement

PA

VE

ME

NT

SE

CT

ION

37 days/YR

Near 50% Loss

“One major factor that degrades a roadbed’s ability to function is the infiltration of water into the base

material.” Caltrans Pavement Evaluation Manual

Pavement Condition Survey John Poppe

Moisture intrudes through pavement: 33-67%

Deteriorating Impact of Moisture Intrusion

Asphalt up to 50% Concrete up to 67%

FHWA REPORT: FHWA/RD-73/14

Reflective Cracking

PCC Joint Cracking Thermal Cracking Lane Widening

It is important to understand the type of movements associated with a particular crack type

Types of Deteriorating Cracks

Point Load Distribution

Interlayer Functions that Delay Deterioration

Mitigate Impact of

Top

HMA-WMA

Layers

Aggregate Base

Protected from moisture saturation

Stress Absorbing/Dispersing Paving Interlayer

Bottom

HMA

Layers

Mitigates Weather /

Environmental Effects

Stops water intrusion

Thermal

Movement Return and Severity

Delay

Crack

Pavement Deterioration Delay

Polypropylene

Chopped Fiber

12.5 kN 30 kN 50 kN 25 kN 50 kN

80 kN 50, 100kN 50, 100 kN 50, 100, 200 kN 50, 100, 200 kN TF

Paving Interlayer Types

MATS

FABRICS

Continuous Strand Fiberglass

Self AdhesiveFabric plus Grid

Uncoated Glass Protective Coated Glass

Protective Coated GlassUncoated Glass

COMPOSITE GRIDS GRIDS

Mills + Recycles

into new mixTensile

Reinforcement

Interlayer Selection by Function

Stress

Absorbing

Stress Absorbing Geosynthetic Interlayer

FunctionMoisture

Barrier

Membrane

Crack Stress Relief and Delay

Fab

ric

Polypropylene YES Low NO Maybe*

Ma

t

Fiberglass/Polyester YES Med Up to 50kN YES

Composite Grid YES Med-High Up to 100kN Maybe*

PreCoated Self Adhesive NO High Up to 200kN YES

PreCoated Self Adhesive TF YES Max High Up to 200kN YES

*Claim is that when fully saturated with asphalt will mill and recycle completely, Need independent confirmation.

Grid

s

Fiberglass Tensile Reinforcing Geosynthetic Interlayers

Caltrans– Paving Mat Spec

Interlayer Index Property Measures

In-Place Validation Testing

4 Point Strain

Controlled

Beam Test

Interlayer Performance Measures

Plate Load Testing


4 Point Notched Beam Testing


4 Point Notched Beam Test Repeatability

0

200

400

600

800

1000

1200

1400

1600

0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16

Load

(lb

s)

Displacement (Inches)

GP50#3

GP50#1

GP50#2


4 Point Notched Beam Testing

4 Point Overlay Test


Interlayer Effectiveness

Comparison of reflective cracks Texas DOT TRB, January 1989

75 % / 30% / 20% @ 6 yrs

1 ¼” AC w Fabric—Cost 31% more/45% less cracks + moisture barrier

2 ½” AC--Cost 100% more/55% less cracks/NO moisture barrier

$5.71

$7.50

$11.43

Pavement Age (Time In Years)

Excellent

Good

Fair

Poor

Failed

Pavement

Pa

ve

me

nt

Co

nd

itio

n

Time For New Overlay

Possibly Recycle

Original Pavement HMA Overlay w/

Interlayers

HMA Overlay Only

Yr X Yr Y

Interlayer Effectiveness

No Interlayer

NEW or REHAB OVERLAY PAVEMENT

Delay Deterioration - Extend Life (Yr Y – Yr X):

Mat 2.75 times

longer

Interlayer Impact on Pavement Deterioration Curve

Crack Delay

using an

interlayer

Interlayer Creates Moisture Barrier

Seals cracks to keep water out of base

Preserves load bearing capacity

Single chip seal

Existing Cracked

Pavement

HMA-WMA Overlay

Asphalt Saturated

Paving Interlayer

Delays reflective cracking

Eliminates surface water infiltrationSurface water

infiltration into base

• Definition:

– Increase the structural life of the asphalt overlay by using an interlayer with a modulus advantage over the asphalt

• Similar to steel in concrete

Interlayer Reinforcement

Tons SF SY

Local HMA Cost: $97.00 Ton Density 110 Lbs/Inch 0.055 $0.59 $5.34 $0.30

$/SF $/SY

$1.19 $10.67 1 2 $5.34

$/SY % + Cost $/SF $/SYAdded

Perf.*

Maint.

Savings

Added

Life²

$4.40 41% $1.67 $15.07 6 12 500% $3.00 18.0 $0.67

12.0 500% $7.11 $64.02 1 12 500% $3.00 12.0 $5.09

SY Cost

Per Year

***The industry standard is that cracks reflect through HMA at the rate of 1 inch per year on average.

BUDGETARY - Paving Mat Interlayer Cost/Benefit CalculationValue of crack mitigation, base structure preservation and maintenance savings

Per SY/Per Yr

Cost of Hot Mix Asphalt InstalledCost/In

Maintenance Cost¹

Change the RED cost numbers in this tool to the local cost to change this sample, to a job specific calculation.

²Added Life is from Cedergren Study showing that base saturation as l ittle as 10% of time can result in near 50% loss of pavement life.

¹ Crack delay and reduced severity = less road closure and maintenance. Crack fill cost is from Maryland study

* IPF=Interlayer Performance Factor from Texas Transportation Insti tute (TTI) Study comparing crack delay of di fferent interlayer types .

**The average budgetary installed cost at maximum daily production. Every job can have significant variables that will

impact the actual project cost.

Yrs to

Crack IPF*

Inch

2.0

Cost of HMA/WMA Pavement

ONLY with

NO Paving Interlayer

Total Cost Installed

50kN Paving Mat

Interlayer Added Cost Installed**

HMA/WMA thickness needed to achieve

same reflective crack reduction***

Interlayer

Thickness Added Value

Interlayer Performance Expectations

Interlayers probably would not have helped!

Extreme Pavement and Base Failures

Depressed pavement/unstable base

Slab Fracture/Uneven

Extreme Fatigue Cracking

Caution! Not all conditions interlayer appropriate!

Site Selection for Success

Mix Rutting

Wide Thermal Cracks

Paving Interlayer Performance

Installation Quality

a. Asphalt binder application

b. Overlay thickness

c. Surface prep & cleaning

d. Large wrinkles cut, laid flat

Control with Specs and QA/QC

Interlayer Installation

Typical Street

Street Prep

Spread Hot Asphalt Binder

Paving Mat Install

Crack Repair Install

Paving Overlay Install

Grid InstallPaving Overlay Install

Finished

No Interlayer

2006

2008

2012

Section 1Installed 2004

2” HMA Overlay on PCC- No Interlayer

2006 2012

Section 2 Installed 2004

2” HMA Overlay on PCC with Paving Mat

Paving Mat Install

BEFOREPaving Mat

Paving Mat Install

Lake Oswego-Boones Ferry

Sep 2007

Paving Mat Install

Oct 2012 7 Yrs AFTERLake Oswego-Boones Ferry

Jun 2014

2” HMA Overlay After 7 Years

Oct 2012 No Interlayer installed

Lake Oswego

Interlayer Advantage Summary

Interlayers delay deterioration

1. Delay & reduce crack severity

2. Preserve the base structure

3. Add flexural strength

4. Reduce maintenance cost and road

closure

Longer lasting roads = Cost savings +

Improving PCI of road inventory

BEST VALUE for Long Life Pavements

Thank You

QUESTIONS?

Dennis Rogers, Reg. Mgr.Pavement Maintenance

Cell: 760 668 3406Email: [email protected]

INTERMISSION

WELCOME

Pavement Maintenance

Dennis RogersRegional Manager, West

GRCS CAPA WebinarGeosynthetic Reinforced Chip Seal

12-2-15

Cost Effective Pavement Preservation

GRCS - Chip Sealing over Paving Interlayer

Super charged chip seal pavement preservation

treatment

Most flexible, durable preservation, longest

pavement life

No other preservation provides this level of base

protection

NO treatment can perform as well for the cost

Hot PG Asphalt Tack Application DPW

Double Chip Seal over Interlayer Application

4 Oz Paving Fabric Installation into Hot PG Asphalt Tack DPW

Double Chip Seal over Fabric Application

Paving Mat Installation into Hot PG Asphalt Tack DPW

Double Chip Seal over Mat Application

Rubber Tire Rolling to “Seat” the Interlayer DPW

Interlayer immediately rolled to ensure removal of all voids, and to get full

embedment of fabric into hot asphalt and adhesion to old pavement


Chip Oil Application

Emulsion or Hot Asphalt Chip Oil Applied on top of Interlayer


Chip application into Emulsion or Hot Asphalt

Emulsion or

Hot Asphalt

Hot

Tack

Interlayer

1st Course Chips


Rolling Chips to “Seat”, then sweep


Chip Oil Application

2nd Chip Oil Applied on top of First Chip


Emulsion Application

2nd Chip applied on top of second chip oil application


Emulsion Application

2nd rolling to seat chip, then sweep


Single chip seal

Existing Cracked

Asphalt Pavement

Double Chip Seal

Asphalt Saturated

Paving Fabric

Delays reflective cracking

Eliminates surface water infiltration

Durable, flexible system that accommodates thermal

movement, keeps cracks sealed and water out of

base, preserving load bearing capacity


The longer life difference:

Flexibility, Cracks Sealed, Base

Protected AT HALF THE COST


Function

Factors*

5 % Asphalt 13.59 % Air Voids 0

- % Fabric 0.5

95 % Rock 86

NOMoisture

BarrierYES

100%SF Cost

Differential50%

2 Yrs Flexibility 20+ Yrs * % Calculation by Wt.

2 Yrs Crack Free 20+ Yrs

2 Yrs Base Protection 20+Yrs

GRCS System Functional Capability compared to 2" HMA/WMA Overlay

Cross Section Cross Section

GRCS-Flexible Chip Seal over Fabric System

Existing base layer

Old Existing HMA LayerOld Existing HMA Layer

HMA/WMA Layer, Min. 2"

Existing base layer

Polymer Emulsion Chip Seal

Polymer Emulsion Chip Seal

MPV500 Paving Fabric

Hot PG Asphalt Binder

HMA/WMA Overlay

60

After 25 Years– Sacramento, Calif.

Cost for this Install

$1.40 to $1.80 per SF

Cost for this Install

$0.75 to $0.85 per SF

HMA Overlay GRCS

GRCS at half the cost of HMA yet double the performance!

The power to stay flexible to seal and delay cracks

After 30 Years – Sacramento, Calif.


Where GRCS Stops, 25 years later

Double Chip

Single Chip

HMA


The interlayer continues

to bridge the surface of

the underlying crack

and eliminate the need

for further crack sealing.

After 15 Years


Before Clear Lake, CA After 14 Years


Before Clear Lake, CA After 10 Years


GRCS - Chip Seal over Interlayer ApplicationInstalled 2005 Woodbridge Rd, Stockton, CA

Chip with and without Fabric after 10 Yrs.

Without FabricWith Fabric

Before Gardnerville, Nevada After 7 Years


Before Gardnerville, NV After 7 Years


With Fabric

Whitlow St, Boulder, CO

Without Fabric AFTER

8/2014

BEFORE 7/2007


Davis Transportation Research News 228

Pavement Life Extension

Added life due to moisture barrier preserving the base.

Life

Chip Seal over Interlayer Application

Chip & Crack Fill Chip/Ground Rubber Binder & Crack Fill

Yr 11 Chip & Crack Fill

Yr 5 Crack Fill

Fabric Chip Seal & Crack Fill



Yr 16 Chip Seal

$-

$1,000,000

$2,000,000

$3,000,000

$4,000,000

$5,000,000

$6,000,000

Chip Seal Rubberized Chip Seal Fabric & Chip Seal

San Diego County Chip Seal Life Cycle Cost Analysis 30 Yr

$5,206,290

$3,993,867

$2,615,032

Davis Transportation Research News 228

GRCS Use Summary

No Higher Value Preservation System

More than double life of Chip Seal treatment

Seals and protects base

Polymerized asphalt and high content

makes it flexible, durable

NO treatment for the cost can perform as well

Thank You

QUESTIONS?

Dennis Rogers, Reg. Mgr.Pavement Maintenance

Cell: 760 668 3406Email: [email protected]

welcome apwa 2015northernca.apwa.net/content/chapters/northernca... · distressed pavements...

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