LTPP and Pavement Preservation

MWPPP Annual Meeting Kansas City, Missouri Monday – September 28, 2015

Gonzalo Rada, Ph.D., P.E. Amec Foster Wheeler E&I, Inc. Principal Investigator

Agenda

1. Background

2. Overview of Experiment Approach & Key Considerations

3. Experimental Designs & Project Layouts

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1. Background

3

LTPP Mission

Increase pavement life by investigation of various designs of pavement structures and rehabilitated pavement structures, using different materials and under different loads, environments, subgrade soil, and maintenance practices

“Understand how pavements behave and why they behave as they do”

4

Design pavement preservation experiments for the LTPP program

Enable LTPP to provide short- and long-term performance data on pavements relative to preservation technology

Verify preservation as a viable technology in extending pavement life

Document impacts of preservation to enable development and implementation of important products and tools

Project Objective

Phase I • Expert Task Group (ETG) • Experiment Designs • Materials Sampling & Testing Plans

Phase II • Performance Monitoring Requirements • Construction Requirements for RSCs • Other Data Collection Needs • Technical Support & Marketing

Project Activities

Provide review/feedback throughout development of experiment

Expert Task Group (ETG)

Anita Bush (Nevada DOT)

Colin Franco (Rhode Island DOT)

Morgan Kessler (FHWA) David Luhr (Washington

State DOT)

Magdy Mikhail (Texas DOT)

Jim Moulthrop (FP2) Larry Scofield (IGGA) Roger Smith (Texas

A&M University)

2. Overview of Experiment Approach & Key Considerations

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LTPP Pavement Preservation Experiments

SPS-11 AC Pavement Preservation Study

SPS-12 PCC Pavement Preservation Study

Two experiments; consistent with other LTPP experiments

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Experimental Approach Segregate treatment types and pavement

project locations into discrete groups Apply same preservation treatment, at

different times, on same pavement structure LTPP focus is on timing/distress propagation

rates, while NCAT/MnROAD studies and others focus on treatment comparisons…

LTPP and NCAT/MnROAD studies complement / supplement each other

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Example SPS-11 Project 6 test sections – 1 control (no overlay) and 5 treatment sections:

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Trea

tmen

t Tes

t Sec

tion

5 (8

yea

rs)

Trea

tmen

t Tes

t Sec

tion

3 (4

yea

rs)

Trea

tmen

t Tes

t Sec

tion

1 (0

yea

rs)

Con

trol

Tes

t Sec

tion

Trea

tmen

t Tes

t Sec

tion

2 (2

yea

rs)

Trea

tmen

t Tes

t Sec

tion

4 (6

yea

rs)

Traffic

AC Pavements (SPS-11)

• Thin HMA overlays (< 1”) • Chip seals • Micro Surfacing

Preservation Treatments

PCC Pavements (SPS-12) • Diamond grinding & DBR • Joint sealants • Joint penetrating sealers

Pavement Types

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SPS-11: • AC overlay of existing AC pavement (AC/AC)

SPS-12 : • Original jointed plain concrete pavement

(JPCP)

Climate Thresholds: Precipitation of 20

inches/year Freezing Index of

150°F-days/year

MERRA data

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Traffic SPS-11 experiment considers both

volumes and ESALs, while SPS-12 only considers ESALs

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100,000 200,000 300,000 400,000 500,000 600,000 700,000 800,000 > 900,0001,0002,0003,0004,0005,0006,0007,0008,000

> 9,000

Annual ESALsV

eh

icle

s p

er

Da

y

LOW

HIGH

Replicates, Repeats & Supplemental

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Replicates: Two per experimental cell; will depend on

funding Repeat: Control test section plus test sections that

have not received treatment Supplemental: Highly encouraged; will be supported and

monitored by LTPP

3. Experimental Designs & Project Layouts

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SPS-11 Matrix

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Mois

ture

Tempe

ratu

re

Sub-Experiment / Treatment

High Low High Low High Low High LowTra

ffic

Wet Dry

Freeze No Freeze Freeze No Freeze

Thin AC OverlayChip SealMicro-Surfacing

Typical SPS-11 Layout

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Trea

tmen

t Tes

t Sec

tion

5 (8

yea

rs)

Trea

tmen

t Tes

t Sec

tion

3 (4

yea

rs)

Trea

tmen

t Tes

t Sec

tion

1 (0

yea

rs)

Con

trol

Tes

t Sec

tion

Trea

tmen

t Tes

t Sec

tion

2 (2

yea

rs)

Trea

tmen

t Tes

t Sec

tion

4 (6

yea

rs)

Traffic

SPS-12 Matrix

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Mois

ture

Tempera

ture

Treatment High Low High Low High Low High LowTra

ffic

Freeze No Freeze Freeze No Freeze

DryWet

Diamond Grinding & Dowel Bar Retrofit

Joint Sealant

Joint Penetrating Sealers

Diamond Grinding & DBR

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Diam

ond

Grin

ding

(5

yea

rs)

Diam

ond

Grin

ding

&

DBR

(5 y

ears

)

Con

trol

Tes

t Se

ctio

n

Diam

ond

Grin

ding

(0

yea

rs)

Diam

ond

Grin

ding

&

DBR

(0 y

ears

)

Diam

ond

Grin

ding

(1

0 ye

ars)

Diam

ond

Grin

ding

&

DBR

(10

year

s)

Traffic

Joint Sealant

22

Seal

ant C

appe

d @

10

Yea

r Int

erva

ls

Seal

ant R

epla

ced

@ 1

0 Ye

ar In

terv

als

Con

trol

: No

Seal

ant

Cont

rol:

Seal

ant

Mai

ntai

ned

Cont

rol:

Seal

ant

kept

As-

Is

Seal

ant C

appe

d @

5

Year

Inte

rval

s

Seal

ant R

epla

ced

@ 5

Yea

r Int

erva

ls

Traffic

(Cap/Replace Sealant)

Penetrating Sealer

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Seal

er a

t Yea

r 5; R

e-

Appl

y @

5 y

ear I

nter

vals

Seal

er a

t Yea

r 5; D

o N

ot

Re-A

pply

Con

trol

: No

Join

t Se

alan

t (re

mov

e if

pres

ent);

No

Seal

erCo

ntro

l: Jo

int S

eala

nt

Mai

ntai

ned;

No

seal

er

Cont

rol:

Join

t Sea

lant

@

Year

0, b

ut N

ot

Mai

ntai

ned;

No

seal

er

Seal

er a

t Yea

r 0; R

e-

Appl

y @

2 y

ear I

nter

vals

Seal

er a

t Yea

r 0; D

o N

ot

Re-A

pply

Traffic

(Silanes or Siloxanes)

Typical Test Section

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100 ft 50 ft 500 ft 50 ft 100 ft

Sam

plin

g Ar

ea

Buff

er A

rea

Test

Sec

tion

Buff

er A

rea

Sam

plin

g Ar

ea

Summary Phase I: Experiment Designs and MS&T

Plans will be completed shortly Phase II: has been approved and work will

commence shortly Project Schedule: construction and data

collection guidelines will be completed by next fall and, once done, will start to recruit projects

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