Status of the first experiment at the PaveLab

Fabricio Leiva-Villacorta, PhDJose Aguiar-Moya, PhDLuis Loria-Salazar, PhD

August 31st, 2015

Research Philosophy…

NANO

FULL SCALE

MICRO

MACRO

Phase I Experiment

• 4 Different pavement structures, 8 sections• Compare

– Asphalt concrete thicknesses– Granular vs. cement treated base

• Evaluate construction practices• Painting evaluation under tropical climate

HMA HMAHMA HMA

GBGB

CTBCTB

SB SBSB SB

0

5

10

15

20

25

0

10

20

30

40

50

60

70

AC1 AC2 AC3 AC4

Thic

knes

s, in

Thic

knes

s, cm

Test Section

Real pavement

Phase I Experiment

Sifón-La Abundancia

Instrumentation

• Laser profiler• Pavement Strain Transducers (PAST)• Soil Pressure Transducers (SOPT)• Multi-Depth Deflectometer (MDD)• Road Surface Deflectometer (RSD)• Thermocouples

Subgrade

Subbase

GB/CTB

HMA

60 cm

MDD MDD

30 cm

Thermocouple

90 cm

Section Length = 6.0 m

Gauge Array

20,000 bi-directional load repetitions per day Carriage speed: 10 km/hr Applied load: 40, 60, 70, 80 kN Test tire: Dual 11R22-5 Wheel wandering: 100 mm Dry condition 23/7

Test Settings

Facility improvements

Material Properties

Property Subgrade Subbase Base Base for CTB CTBWopt (%) 52.5 8.9 8.6 11.5 11.5

gd max (kg/m3) 1056 2204 2217 2013 2013

LL 56 - - 24.8 - PI 16 NP NP 4.4 -

CBR, % 6.6 95 95 Pend. 35 kg/cm2

QC SpecsNMAS, mm 19

AC, % 4.9 VMA 14.9 Min 14%VFA 72 65-75%

Estability, Kg 1482 Min 800

Flow 30 20-35 cm/100DP 1.04 0.8-1.3

Sieve Passing, % Specs25.4 mm 100 10019.1 mm 99 90-10012.7 mm 77 70-809.5 mm 65 55-65

N 4 41 35-43N 8 28 22-30

N 16 20 16-22N 30 14 11-17 N 50 10 7-14

N 200 4.9 2-5.8

Granular and CTB

HMA

FWD

FWD0 200 400 600 800 1000 1200 1400 1600 1800 2000

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

AC1

AC2

AC3

AC4 Sensor Location (mm)

Defl

ectio

n (m

m E

-2)

Layer M (MPa) M (ksi)HMA 3800 551CTB 1200 174Base 170 25

Subbase 140 20Subgrade 70 10

HMA HMAHMA HMA

GBGB

CTBCTB

SB SBSB SB

0

5

10

15

20

25

0

10

20

30

40

50

60

70

AC1 AC2 AC3 AC4

Thic

knes

s, in

Thic

knes

s, cm

Test Section

Laser Profile

MDD´s

Permanent Deformation-Laser

Average deformation (entire section)

10.16

2.57

12.64

6.13

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

0 5 10 15 20

Perm

anen

t def

orm

ation

, mm

MESALs

AC1

AC4

AC2

AC3

HMA HMA HMA HMA

GBGB

CTBCTB

SB SBSB SB

0

5

10

15

20

25

0

10

20

30

40

50

60

70

AC1 AC2 AC3 AC4

Thic

knes

s, in

Thic

knes

s, cm

Test Section

IRI

Average of wheelpath

2.46

1.17

2.50

1.99

0.00

0.50

1.00

1.50

2.00

2.50

3.00

0 5 10 15 20

IRI (

m/k

m)

MESALs

AC1 AC4

AC2 AC3

HMA HMAHMA HMA

GBGB

CTBCTB

SB SBSB SB

0

5

10

15

20

25

0

10

20

30

40

50

60

70

AC1 AC2 AC3 AC4

Thic

knes

s, in

Thic

knes

s, cm

Test Section

Stress @ subgrade

0

5

10

15

20

25

30

35

40

0 2 4 6 8 10 12 14 16 18 20

Pres

sure

, kPa

MESALS

AC1

AC2

AC4

AC3 pressure cell did not workHMA HMA

HMA HMA

GBGB

CTBCTB

SB SBSB SB

0

5

10

15

20

25

0

10

20

30

40

50

60

70

AC1 AC2 AC3 AC4

Thic

knes

s, in

Thic

knes

s, cm

Test Section

MDD´s

-0.3

-0.25

-0.2

-0.15

-0.1

-0.05

0

0.05

0 1 2 3 4 5 6

Defl

ecti

on, m

m

Distance, m

mdd1-0

mdd1-180

mdd1-450

mdd1-700

mdd2-60

mdd2-300

mdd2-600

mdd2-900

60 cm

MDD MDD

30 cm

Thermocouple

90 cm

Section Length = 6.0 m

Max. Deflection @ 40 kN - MDDs

00.20.40.60.8

11.21.4

0 5 10 15 20

MD

D S

urfa

ce

Defl

ecti

on, m

m

MESALS

AC1AC4AC2AC3

0

0.1

0.2

0.3

0.4

0.5

0 5 10 15 20

MD

D S

ubgr

ade

Defl

ecti

on, m

m

MESALS

AC1AC4AC2AC3

Surface

Subgrade

HMA HMAHMA HMA

GBGB

CTBCTB

SB SBSB SB

0

5

10

15

20

25

0

10

20

30

40

50

60

70

AC1 AC2 AC3 AC4

Thic

knes

s, in

Thic

knes

s, cm

Test Section

MDD Backcalculaded Layer Moduli

1

10

100

1000

10000

0 250000 500000 750000 1000000

Back

calu

late

d M

odul

us, M

Pa

Repetitions

M1 M2 M3 C

y = 1.0016xR² = 0.9962

0

100

200

300

400

500

600

700

0 100 200 300 400 500 600 700Es

tim

ated

Defl

ecti

on, m

m-3

Measured Deflection, mm-3

DeflectionEquality

n

dSR MPa

CE

1.0

Average “n” value = -0.4

Deflections @ 40 kN

AC1

CR-ME

RSD-AC1

00.10.20.30.40.50.60.70.80.9

1

0 100000 200000 300000 400000 500000 600000 700000 800000 900000 1000000

Defl

ecti

on, m

m

Repetitions

N1 S1 N2 S2

60 cm

MDD MDD

30 cm 90 cmRSD – N1 RSD – N2

RSD – S2RSD – S1

100 cm

Construction variability !!!

Deflections @ 40 kN

RSD-AC4

2 different locations along the center line

10

100

1000

10000

0 5 10 15 20

Back

calc

ulat

ed M

odul

us,

MPa

MESALs

HMA CTB SBG SG10

100

1000

10000

0 5 10 15 20

Back

calc

ulat

ed M

odul

us,

MPa

MESALs

HMA CTB SBG SG

Strain Transducers

AC2 @ 2k rep.

-200

-100

0

100

200

300

400

500

0 1 2 3 4 5 6

Mic

rost

rain

Distance, m

LongitudinalTransverse

-200

-100

0

100

200

300

400

500

0 1 2 3 4 5 6

Mic

roSt

rain

Distance, m

Longitudinal

Transverse

AC2 @ 1M rep.

Strains @ 40 kN

AC2Strains @ 40 kN

0

100

200

300

400

500

600

700

800

0 1 2 3 4 5 6 7 8 9 10

Mic

rost

rain

MESALS

Longitudinal

Transverse

Water added to surface

Strain Transducers

AC2

AC3Strains @ 40 kN

0

100

200

300

400

500

600

700

800

900

0 2 4 6 8 10 12 14

Mic

rost

rain

MESALS

Longitudinal

Transverse

Evidence of fatigue cracking

Strain Transducers

Fatigue cracking

AC3

Just over 50 Million ESALs

Test section Repetitions ESALS

001 AC1 1 000 000 10 708 004

002 AC4 1 500 000 21 550 195

003 AC2 1 000 000 9 350 541

004 AC3* 1 240 000* 11 066 122*

*Until August 2015

Deflection Analysis

0

100

200

300

400

500

0 500 1000 1500 2000

Defl

ecti

on, m

m-3

Sensor Location, mm

FWD

RSD

MDD

0

400

800

1200

1600

2000

0 200 400 600 800

Sens

or L

ocati

on, m

m

Surface Modulus, MPa

FWD

RSD

MDD

Initial state

Captures non-linear behavior of the lowers layers.

Deflection Analysis

Failure State

0

200

400

600

800

1000

1200

1400

0 500 1000 1500 2000

Defl

ecti

on, m

m-3

Sensor Location, mm

FWD

RSD

MDD

0

400

800

1200

1600

2000

0 50 100 150 200 250

Sens

or L

ocati

on, m

m

Surface Modulus, MPa

FWD

RSD

MDD

2.5 – 3 times higher More intensified non-linear behavior of the lowers layers. Exhibits the presence of the test pit concrete support layer (shallow rigid layer).

Lab. Characterization

Sample

APA (AASHTO TP 63) HWT (AASHTO T324) FN (AASHTO TP 79-11)

% Air Voids PD, mm % Air Voids PD, mm FN @ 58 °C FN @ 52 °C FN @ 46 °C

Plant Produced 7.7 2.751 7.5 3.35 178 418 1523

Lab Prepared 7.9 2.121 8 8.28 153 307 1493

Sample

TSR (AASHTO T283) Mr (AASHTO TP31-96/ASTM 4123)

1 Cicle 3 Cicles 6 Cicles % Air Voids Mr @ 5 °C, MPa

Mr @ 25 °C, MPa

Mr @ 40 °C, MPa

Plant Produced 101 85 77 7.7 17362 5703 2207Lab Prepared 96 78 62 7.2 17522 5619 2121

100

1000

10000

100000

1000000

0 200 400 600 800 1000

Repe

titi

ons

Strain

4PBB Test (AASHTO T321)

Plant 30°CPlant 20°CPlant 10°CLab 30°CLab 20°CLab 10°C

• Perm. Def. HMA

Transfer functions𝜀𝑝𝜀𝑟 = e−10.919𝑇2.961𝑁0.355

𝑁𝑓 = e37.352ሺ𝜖ሻ−4.554𝑒0.094𝑇 • Fatigue HMA

𝜀𝑝 = 10−4,998 ∗𝑁0,069 ∗𝜎𝑑 1,687 ∗𝜎30,077 ∗%𝑤1,881 • Perm. Def. Gran. Base

𝜀𝑝 = 10−32,954 ∗𝑁0,040 ∗𝜎𝑑 2,041 ∗𝜎30,421 ∗%𝑤16,983 • Perm. Def. Subgrade

Lab developed models are being calibrated with HVS results

MLET

Linked to software development

HMA MASTER CURVES SOFTWARE

AppRIGID CR-ME 2.0 –EXCEL BASED-

FUTURE

Climatic Condition Chamber- Infrared + UV: Temperature +

aging- Raining system moisture- Water table simulation

Summary

• Increase in Deflections• Increase in vertical stress• Increase in horizontal strain

• Visible low severity cracks (fatigue) within effective section for AC2, AC3 (granular base).

• Cracking pattern initiates with transverse cracks @ 30 cm, then @15, finally blocks are formed

Cumulative damage

Thank You!

http://www.lanamme.ucr.ac.cr/pavelab

APT 2016

Important dates

1. October 9, 2015: Deadline for submission of full paper for peer review

2. January 15, 2016: Comments, notification of acceptance/rejection of

full paper

3. March 11, 2016: Submission of full, revised paper

September 19-21, 2016: APT 2012 Conference