Diseño Estructural y Comportamiento de

Recubrimientos Delgados de Hormigón

Prof. Jeffery Roesler, Ph.D., P.E.

Department of Civil & Environmental Engineering

University of Illinois Urbana-Champaign

President, International Society of Concrete Pavements

Pasado, Presente y Futuro de la Sociedad Internacional para Pavimentos de Concreto (ISCP)

Dr. Jeffery Roesler, P.E.

President, International Society for Concrete Pavements (ISCP)

27 Octubre 2016

Nuestra Misión

La misión del ISCP es “facilitar el avance de conocimiento

y tecnología relacionados a pavimentos de concreto a través

de la educación, el intercambio de tecnología y la

investigación a nivel internacional.

Breve Historia sobre la ISCP

• Concebida después de la sexta conferencia de Purdue (Noviembre 1997)

• Incorporada en Mayo de 1999 como un grupo voluntario sin ánimo de lucro

• Ha organizado Conferencias Internacionales en Orlando, 2011, Colorado Springs, 2005, San Francisco, 2008, Quebec City, 2012, San Antonio, 2016

• Ha sido anfitriona/patrocinadora de Conferencias Regionales/Talleres en

AustraliaSouth AfricaChinaBrazil, Chile, PeruU.S.Spain, CzechGuatemala…….

• Diálogo activo en línea

Nuevo sitio interactivo

• Ruptura de la Barrera de Lenguaje

Guía para Capas de Refuerzo con Concreto en español

• Transferencia de Tecnología en el Sitio

Participar en eventos como este

Onceava Conferencia Internacional

• Transferencia de Tecnología En Línea

Seminario técnico y patrocinado en línea

concretepavements.org/11thiccp

Actividades

Comité de Ejecutivo - ISCP

President: Dr. Jeff Roesler, University of Illinois

Vice-President: Byran Perrie, The Concrete Institute (South Africa)

Treasurer-Secretary: Dr. Jake Hiller, Michigan Tech Univ. (USA)

Past President: Dr. Neeraj Buch, Michigan State (USA)

Miembros de Board - ISCP

Dr. Lev Khazanovich, University of Minnesota (USA)

Corey Zollinger, CEMEX (USA)

Dr. Rolf Breitenbücher, Ruhr-University (Germany)

Leif Wathne, American Concrete Pavement Association (USA)

Juan Pablo Covarrubias, TCPavements, Ltda. (Chile)

George Vorobieff, RTA (Australia)

Dr. Someyah Nassiri, Washington State (USA)

Tim Smith, Lafarge-Holcim (Canada)

Luc Rens, EUPAVE (Belgium)

Sherry Sullivan, Cement Association of Canada

Erwin Kohler, 3ipe (Chile)

Anne-Carin Brink, AECOM (Australia)

Dr. Peter Taylor, Iowa State University (USA)

100+ technical papers

14 Podium Sessions (~56 papers)

4 Poster Sessions (~45 posters)

Student Posters (~20 posters)

11 Workshops – practical, applied content (repeated)

Site visits – Steel plant, cement plant

Visitános• Nueva y mejorada página web

www.concretepavements.org

• Miembro Individual

• Miembro Corporativo

-Gold

-Silver

-Bronze

Recapados de Hormigón (O/L)

(Vista general)

Overlay Design Objectives

Overlay Design Guides

Inputs & critical variables

Bonded Concrete Overlays

Concrete-Asphalt

Performance of Illinois O/L

Unbonded Concrete Overlays

Summary of Overlay Design

References for O/L design

Diseño de Recapados de Concreto: Objetivos

Achieve desired concrete pavement overlay

service life given:

Existing pavement condition

Expected traffic

Layer and material properties

Interface condition

Slab geometry

Climatic conditions

SCinitialSCOverlay

SCeffective

SCfuture traffic

Load Applications

Estados con Experiencia en Recapados

With concrete overlay experience (mainly overlays on asphalt)

With little known concrete overlay experience

Illinois

Recapados de Hormigón

en Illinois (2015)

17

Overlay Type - 97

Bonded (PCC/PCC)(12)

Unbonded (PCC/Comp.)(11)

Whitetopping (UB) (15)

UTW or WT (B) (46)

UTW/Unbonded Hybrid (13)

http://www.ilacpa.com/Whitetopping%20Links/Project_List.pdf

Como minimo 1000 proyectosrecapados en EEUU.

911 Items filtered from 1207

Guía en Métodos Existentes de Diseño de

Recapados

Not a design procedure

Background on

recommended overlay

design methods

18 pages

Detailed design examples

35 pages

StreetPave12 released

after this guide

http://www.cptechcenter.org/technical-library/documents/Overlays_Design_Guide_508.pdf

Cómo empezar el diseño del concreto O/L?

Roadway site evaluation

Existing pavement structure

New pavement performance objectives

Select potential Overlay Options

Collect input data & choose design features

Support layers, Slab size, etc.

Use appropriate overlay design methods

Optimize design

Write construction specifications to reflect design

objectives

Recapados de Concreto: Tipos Generales

Whitetopping (unbonded) Bonded Concrete Overlay Asphalt (BCOA)

Bonded Concrete to Concrete Unbonded Concrete w/ Separation Layer

Not common

Guía para Recapados con Hormigón, Tercera

EdiciónContents

Overview of Overlays

Overlay types and uses

Evaluations & Selections

Six Overlay Summaries

Design Section

Misc. Design Details

Overlay Materials Section

Work Zones under Traffic

Overlay Construction

Accelerated Construction

Specification Considerations

Repairs of Overlays

http://www.cptechcenter.org/technical-library/documents/Overlays_3rd_edition.pdf

Opciones de Pavimentos de Hormigón

Bonded

Concrete

Resurfacing

of

Asphalt

Pavements

Bonded

Concrete

Resurfacing

of

Composite

Pavements

Bonded Overlay Systems

Unbonded

Concrete

Resurfacing

of Concrete

Pavements

Unbonded

Concrete

Resurfacing

of Asphalt

Pavements

Thinner

Concrete

Pavement or

Short Slabs

Unbonded Systems

ACPA BCOA or BCOA ME

h=8 to 15cm

L=1.2 to 1.8 m

Thin

Concrete

Inlay -

Preservation

h=5 to 9 cm

L=1.2 to 1.8 m

Emerging

Colorado Method

15cm x 1.8x1.8m2

Opti-Pave

h= 6 to 23cm

L= 1.2 to 2.8m

¿Qué metodo(s) de Recapados con concreto?

Concrete Overlay Type Design Methods

Unbonded on Asphalt,

Composite, or Concrete

AASHTO ME, ACPA StreetPave 12,

AASHTO 93, OptiPave 2.0

Bonded on Asphalt or

Composite

ACPA BCOA, ACPA StreetPave 12,

BCOA ME, CO 6x6x6, IDOT Chpt 53

Bonded on Concrete AASHTO ME, ACPA StreetPave 12,

AASHTO 93

• Slab thickness

• Concrete Strength, CTE, Modulus, fibers

• Concrete-Asphalt Interface

• Support layers (surface, base/subbase, soil)

• Joint Spacing

• Edge Support

• Load Transfer

• Subgrade Support

• Traffic & Design Life

• Climate

¿Cuáles son los principales factores de diseño para

las Recapados con Concreto?

Hamilton County, IL

Pre-overlay Repair & Reflective Crack Control

Subsurface drainage

Structural vs. Functional Overlays

Recycling Existing Pavement (PCC & AC)

Existing PCC Slab Durability

PCC Overlay Reinforcement

PCC Overlays Bonding / Separation Layers

Overlay Design Reliability Level

Pavement Widening

Traffic Disruptions and User Delay Costs

Otras Consideraciones Importantes

en el Diseño de Recapados

UTW vs. Whitetopping

Whitetopping (h > 15cm)

Slab sizes (3.5m to 4.5m)

35+ years experience

No interface bond assumed

Ultra-Thin Whitetopping (h ≤ 15cm)

20 years experience

Smaller slab sizes (<2m)

PCC/AC bond is essential

Now called Bonded Concrete Overlay of Asphalt (BCOA)

Mecánica del Comportamiento de Materiales

Compuestos

Unbonded

“Whitetopping”

Neutral Axis

PCC

AC

Bonded

Bonded Concrete Overlay Asphalt

PCC

AC

Soluciones con Capas de Refuerzo:

Rehabilitación y Mantenimiento

Visita al Sitio: Condición del Pavimento Existente

¿Por qué usar losas pequeñas?

1.2m 1.2m1.2m>3m

•Interface bond assumption for bonded overlays-Reduce de-bonding of concrete and asphalt at early ages

•Short slab sizes reduce bending and curling stresses

Diseño del Espesor de Recapados

Highways/Roads

AASHTO Pavement ME (2011) or MEPDG

StreetPave 12 (ACPA)

ACPA (Whitetopping/UTW) – 1998

Illinois DOT (2009) – new fatigue eqn. & fibers

Chapter 53-4.08

BCOA Calculator (2012) – add climate database

BCOA ME (2012) – Univ. of Pittsburg

AASHTO (1993)

Opti-Pave 2.0 (Covarrubias)

Airports:

Federal Aviation Administration (FAARFIELD)

Opciones de Recapados Adheridas

Thinner overlays (8 to 15 cm)

Constructed over concrete,

asphalt, and composite

sections.

Existing pavement condition

fair to good not poor!

Interface Bond is Critical!

Bonded

Concrete

Resurfacing

of

Concrete

Pavements

Bonded

Concrete

Resurfacing

of

Asphalt

Pavements

Bonded

Concrete

Resurfacing

of

Composite

Pavements

Bonded Overlay Options

X

Capa de Refuerzo de Concreto: Adherida al

Asfalto Metodos

AASHTO 1993

Not applicable

AASHTO Pavement ME (2011)

Thickness 15 cm

Slab length 3 m

ACPA (2012);IDOT (2009);Pitt BCOA ME (2013)

Ultra-Thin Whitetopping

Thickness 15 cm

Slab length 1.8 m

Unbonded Concrete

Overlay of HMAX

Capas Delgadas de Refuerzo con Concreto

para Pavimentos de Asfalto (UTW) Relatively Thin Slabs

(8 to 15cm)Square Slabs

(1.2mx1.2m to 1.8mx1.8m)

Milled Surface

preferred

HMA

PCC

Base

40kN 40kN

EAC, uAC

EPCCst

eAC

Subgrade k-value

Bonded

hPCC

hAC

UTW Lugares Críticos (Concreto y Capas AC)

st

If you lose bond

With bond,

corner loading

critical

L

Concrete Fatigue Model - UTW

217.024.10

0112.0

)1log(log

pSRN f

Model Statistics

N = 87

R2 = 91 percent

RMSE = 0.31 (log N)

Nf = Allowable repetitions to failure

SR = stress ratio (s/MOR)

p = probability of failure

Riley et al. (2005)

How to account for % Slabs Cracked?

217.024.10

0112.0

*)log(log

RSR

N total

PCC

)FMOR

σSR TOTAL

total 150

150(

5.0

)1(1* crPR

R

Note:

R = (1-p)

R*=effective reliability

Pcr = % slabs cracked

= residual strength (FRC)

Riley et al. (2005)

Altoubat et al. (2008); Roesler et al. (2008)

Riley (2006)

150

150F

Fibras Estructurales vs. no-estructurales (plastic

shrinkage)

Structural

Macro-Fibers

Micro-Fibers

(non-structural)

0

1

2

3

4

5

0 10 20 30 40CMOD (mm)

Load (

kN

)

MACRO-Fiber Reinforcement BenefitsConcrete Pavements

Increase in structural capacity of slab reduces required slab thickness (e.g., overlays)

Maintain crack/joint widths

Non-uniform support condition

Tie longitudinal/transverse contraction joints Avoid slab migration

Reduce deterioration rates after initial cracking slab deflect and displace more easily

thin concrete overlays deteriorate more rapidly under traffic

Should I use fibers on every concrete pavement projects? NO

ASTM C1609-10Flexural Performance of Fiber-Reinforced Concrete (Third-Point Loading)

Need:

Deflection controlled loading frame

Mid-span deflection gauge

Pin/roller supports

Recommendations:

Beam sizes 150x150x500 mm (6x6x20 in.)

Fibers length < 3*D

Test process:

Load at constant deflection rate until L/150 reached

L = span of beam

D = depth of beam

Flexural Beam Results150x150x550mm

2bd

PLMOR

0

1

2

3

4

5

6

0 0.5 1 1.5 2 2.5 3

Beam Deflection (mm)

Str

ess (

MP

a)

.35% Hooked End Steel Fiber

.50% Crimped Steel Fiber

.32% Synthetic Fiber

.48% Synthetic Fiber

Plain

ASTM C1609-10

Beams:

150x150x530mm

Span: 450mm

L/150 = 3 mm

%100*150

%100*

2

150

150150

150,

150

150

2

2

150

150

150

150150

150

1

bdMOR

TR

orMOR

fR

bd

LPf

bd

LPMOR

T

Slab Test Setup

0

25

50

75

100

125

150

175

200

225

250

0 1 2 3 4 5 6 7 8 9 10 11 12 13

Maximum Surface Deflection at the Slab's Center (mm)

Lo

ad

(k

N)

Plain

0.48% Synthetic Fiber

0.32% Synthetic Fiber

0.35% Hooked End Steel Fiber

0.50% Crimped Steel Fiber

WWR

0

25

50

75

100

125

150

175

200

225

250

0 1 2 3 4 5 6 7 8 9 10 11 12 13

Maximum Surface Deflection at the Slab's Center (mm)

Lo

ad

(kN

)

Plain

0.48% Synthetic Fiber

0.32% Synthetic Fiber

0.35% Hooked End Steel Fiber

0.50% Crimped Steel Fiber

WWR

Peak Load – Plain Concrete

Concrete Slab

Load Capacity

Failure Load Summary (kN)

Slab Type Tensile Flexural Ultimate

Plain 75 108 135

Synthetic

(0.48%)70 143 195

Synthetic

(0.32%)75 135 174

Hooked Steel

(0.35%)70 141 228

Crimped Steel

(0.50%)90 167 220

WWR 65 122 201

Slab/Beam

Flex. Strength

1.39

2.09

1.82

2.01

2.22

1.53

Roesler et al. (2004)

Effect of Fibers on Concrete Slab Flexural Strength

• Fibers improve flexural cracking load over plain concrete

Increase over Plain Concrete Slab

• Synthetic (0.5%) 32%

• Synthetic (0.32%) 25%

• Hooked (0.35%) 31%

• Crimped (0.5%) 55%*

• WWR (6x6-W2.9) 13%*higher concrete strength

Macro-fibers in Concrete Slabs can …

• Reduce slab thickness for same performance

• Increase slab performance for same thickness

• Increase slab size for same performance

• Post-cracking serviceability.

• Structural enhancements depend on fiber performance in specific concrete!

Modified Strength Equations

MOR’ = (MOR + )

MOR = plain concrete flexural strength

F150 = residual strength at L/150 deflection

MOR’ = effective flexural strength of FRC

= 1.0 MPa (for example)

MOR = 5.0 MPa

Stress Ratio (SR) = (Total Stress)

( + MOR)

150

150F

Bordelon and Roesler(2012)Altoubat et al. (2007)

150

150F

150

150F

Cálculo IDOT del Espesor del Concreto

Variable

Design Traffic Factor (BDE Manual, Figure 54-4C) TF 2.50

Modulus of Rupture (3-point bending, 14-day average) MOR 750 psi MOR

FRC Residual Strength Ratio 20%

Remaining Thickness of Asphalt h ac 3.0 in.

Joint Spacing L 72 in. L

Elastic Modulus of Concrete E c 3,600,000 psi E c

Coefficient of Thermal Expansion CTE 5.50E-06 in./in./°F CTE

Elastic Modulus of Asphalt E AC 350,000 psi

Modulus of Subgrade Reaction k 100 pci

k

Thickness of Concrete h c 5.48in.

Solved

Note 1: The design MOR is the mean design strength, not the minimum 550 psi flexural strength (center-point loading)

specified for opening to traffic. Also note that as MOR increases the risk of debonding increases and the effectiveness of

synthetic fibers decreases.

PCC Inlay / Overlay Design Sheet, Required Thickness of PCC

5.50 x 10-6

in./in./°F

E AC

100,000 psi (poor)

350,000 psi (moderate)

3,600,000 psi

0% (w/o fiber reinforcement)

20% (w/ fiber reinforcement)

600,000 psi (good)

100 pci

Default InputsDefault Value

750 psi (Note 1)

48 in. or 72 in.

150150R

Compute Concrete

Thickness

Help

150150R

http://www.dot.state.il.us/desenv/pdp.html

Efecto del Espesor del Asfalto

0

1

2

3

4

5

6

1E+04 1E+05 1E+06 1E+07

ESALs

Co

ncre

te T

hic

kn

ess h

c (

in)

hac = 3 in

hac = 4 in

hac = 5 in

hac = 6in

k = 100 pci

MOR = 650 psi

R150 = 0%

Eac = 350,000 psi

L = 4 ft

ΔT/h = -0.65 °F/in

35 % time

R150= Relación de Resistencia Residual (Fibras)

0

1

2

3

4

5

6

1E+04 1E+05 1E+06 1E+07

ESALs

Co

ncre

te T

hic

kn

ess h

c (

in)

R150,3 = 0%

R150,3 = 15%

R150,3 = 20%

R150,3 = 25%

k = 100 pci

MOR = 650 psi

Eac = 350,000 psi

hac = 3 in

L = 4 ft

ΔT/h = -0.65 °F/in

35 % time

Efecto del Tamaño de la Losa (L)

0

1

2

3

4

5

6

7

8

1E+04 1E+05 1E+06 1E+07

ESALs

Co

ncre

te T

hic

kn

ess h

c (

in)

L = 12 ft

L = 6 ft

L = 4 ft

k = 100 pci

MOR = 650 psi

R150 = 0%

Eac = 350,000 psi

hac = 3 in

ΔT/h = -0.65 °F/in

35 % time

ACPA Adherido O/L de Asfalto

http://apps.acpa.org/applibrary/BCOA/ (2012)

http://www.engineering.pitt.edu/Vandenbossche/BCOA-ME/

BCOA ME Modos de Fallo1.5 to 2.1 m

Long. & Diag

Crack

Positive ΔT Negative ΔT

< 1.4 m

Corner Break

Positive ΔT

3m x 3.6m

3.6m x 3.6m

3.6m x 4.5m

Trans. Crack

Vandenbossche (2013)

Preparación de la Superficie

Milling AC surface

Remove rutting

Restore profile

Enhance bond

Minimum AC thickness remaining after milling: 6.5 cm to 8 cm

Surface cleaning

Waterblast - preferred

Sweeping

Guía sobre Capas de

Refuerzo para

Estacionamientos (2012)

www.rmc-foundation.org/images/Concrete_Overlay_Guide_11-14-12.pdf

Contents:

Parking Lot Features

Existing Pavement Condition

Concrete Overlay Design

Jointing

Parking lot details

Materials

Construction

Fibers

University of Illinois: Estacionamiento E-15

(2006)

8 cm overlay over existing 6.4 cm HMA surface

1.2m x 1.2m panels

1.8 kg/m3 structural synthetic fibers

2012

Estacionamiento – 7 years later (2013)

Nueva sección UTW (1 year - 2013)

2007 Proyecto Estacionamiento McKinley

Estacionamiento McKinley (6 años)

2013

DESEMPEÑO DE SECCIONES UTW

(WHITETOPPING

ULTRA-DELGADO)

Proyectos Visitados en Illinois (20)

Decatur, IL: Intersección de US 36 y

Oakland Avenue (1998)

Major distresses

Longitudinal, transverse or corner cracking in

33.8% of slabs

Faulting throughout the project in joints and

cracks

Three to five instances of partial slab blowups

due to slab migration

Slab migration

Inside five rows of slabs had migrated into the

intersection from 2.5 to almost 15cm at the

end of the project

Use of structural fibers likely could have

locked the panels in and prevented this

movement

2012

Tuscola, IL: US 36 (1999)

Major Issues

Slab migration in opposite directions

in the EB and WB lanes

Water buildup between the outside

slabs and the shoulder

High severity faulting

Joints falling in the wheelpath

Longitudinal, transverse or corner

cracking in 25.6% of slabs

Slab misalignment magnifies

roughness

2012

Kane County, IL: Carretera North Lorang (2004)

11 cm thick concrete overlay of 7.5-9 cm of HMA over

aggregate base

2.4 kg/m3 synthetic macro-fibers

Square 1.5m x 1.5m panels

Project built to serve a quarry: average of 30 trucks/day (peak

of 280/day)

2012

Mundelein, IL: Schank Avenue (2005)

10cm. concrete overlay of a composite pavement (5.7-16.5cm

HMA over 12-23.5cm PCC)

Square 1.2m x 1.2m panels

2.4 kg/m3 synthetic macro-fibers

High truck traffic volume (no data available, but comparable

to Lorang Road and more general traffic)

2012

Hamilton County, IL (2014)

FRC UTW (10cm)

Existing Asphalt Concrete (7.5cm)

Cement Treated Soil (20cm)

Natural Soil

Built in 2013

Built in 9/2014

Built in 9/2014

Uruguay – Ruta 24 de Transporte Forestal (2011)

15 cm slab thickness (south)

13cm slab thickness (north)

1.8m x1.8m slab size

2.5 kg/m3 fibers

Ruta 24 – 23 Octubre 2016

15 cm slab thickness

1.8m x1.8m slab size

2.5 kg/m3 fibers IRI = 2.0m/km

Rt53 (Will County) Detalles del Proyecto

6.9 km section, four lane

divided highway

Design 10 cm concrete inlay of

asphalt over old PCC

1.2m x 1.2m panels

ADT: 7,750 (2013)

Trucks: 12.3% SU, 19.35% MU

(intermodal facilities nearby)

Synthetic macro-fiber

reinforcement: 2.4 kg/m3

Encuesta de Deterioro

Severe distresses near lane-shoulder joint

along right edge of the northbound pavement

Encuesta de Deterioro

Distresses in inner wheel path of right lane,

also in northbound pavement

UTW Testigos (Cores)

Average layer thicknesses from cores taken in

Summer 2014

9 cores in each direction (right lane, center panels)

Difference between concrete and asphalt layer

thicknesses in NB & SB directions statistically

significant with 95% confidence

Direction UTW Concrete

Thickness

(inches)

Asphalt

Thickness

(inches)

Old Concrete

Thickness

(inches)

Northbound 3.86 4.03 9.0

Southbound 4.56 5.06 5.7

Resumen: IL 53 fallas prematuras

Cross slope (pendiente) <1.0% in northbound

Water entered longitudinal joints

1.2mx1.2m slab size detrimental

Very old asphalt layer directly beneath slabs

Signficant de-bonding of concrete-asphalt layers

Heavier trucks than anticipated

Note, southbound lanes are fine

-no major distresses

Retrocálculo de UTW

What do we expect from FWD tests?

What assumptions do we need to make?

What equations do we use?

UTW Modelado de Pavimento

Fixed Input Parameters

Load, P 9,000 lb

Plate Radius, a 6.0 in

Modulus of Subgrade Reaction, k 100 psi/in

Poisson’s Ratio, ν 0.15

Modulus of Elasticity, E 5,000,000 psi

UTW pavement

system was modeled in

Illislab as an effective

concrete slab over

subgrade• Derive relationships

that determine heff

Equaciones de Retrocálculo

𝐴𝑅𝐸𝐴24 = 6 1 + 2𝑑12𝑑0

+𝑑24𝑑0

10 15 20 25 30 35 40 45

16

17

18

19

20

21

22

23

24 LTE=100

LTE=80

LTE=50

LTE=0

AR

EA

-24 (

in)

Radius of Relative Stiffness, l (in)

𝑊𝑖𝑛𝑡 =𝑑0𝑘𝑙

2

𝑃= 𝑓

𝑎

0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45

100

200

300

400

500

600

700

800

LTE=100

LTE=80

LTE=50

LTE=0

Win

t (-

)

a/l (-)

=𝐸ℎ3

12 1 − 𝜈2 𝑘

1/4

King and Roesler (2014) Transportation Research Record: Journal of the Transportation Research Board, No. 2457, pp. 72–79.

Estacionamiento Talbot Lab (1998)

Effective thickness dropped 8.4% from 2008 to 2012

Statistically significant to 90% confidence interval

BUT test sections were not identical for each FWD test

Deteriorating support conditions – original asphalt layer was thin and

now there is panel cracking (22% of all panels)

2012 survey: good condition, still functional

0

2

4

6

8

10

12

14

16

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Effe

ctiv

e T

hic

kne

ss, h

eff(i

n.)

Slab Number

2008

2012

Estimated PCC Thickness

Estimated PCC+AC Thickness

Resultados del Proyecto

0

2

4

6

8

10

12

14

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Eff

ecti

ve

Th

ick

nes

s, h

eff (i

nch

es)

Slab Number

Section 1

Section 2

Section 3

Estimated PCC Thickness

Project, Location (year) &

Panel Size Section

Average Modulus

of Subgrade

Reaction, k (pci)

Average

Effective Slab

Thickness (in)

Thickness

Standard

Deviation (in)

Estimated

Thickness: hPCC +

hAC = htotal (in)

North Lorang Road, Kane

County, IL (2004),

4 ft x 4 ft

1 156 5.89 1.85

4.5 (PCC only)2 394 8.39 1.32

3 379 7.47 0.801

Variable LTE affects backcalculation

Resúmen: Recapados con Concreto Parking lots = 1.2mx1.2m panels are fine w/ fibers

Maintain ~1.8m panel sizes w/ fibers

More cracking/faulting on skewed joints

Thinner saw blades

No sealing except when long. joint in wheel path

No faulting or cracking on 1.2mx1.2m or 1.8mx1.8m slab sizes with macrofibers (>2006)

FRC needs minimum revolutions at high torque in mixer

AC layer or underlying support have potential to be major issues (e.g. Schank Ave) and/or heavy truck traffic, try higher fiber dosages or fix support layer

¿Qué es Flowable Fibrous Concrete (FFC)?

218

Flowable Fibrous

Concrete

Ultra-Thin

Whitetopping

Fiber-

Reinforced

Concrete

Self-

Consolidated

Concrete

High Toughness/

Reduced Cracking

Ease of

Placement

Cost-Effective

Thin Pavement

HPFRSCC (ECC)

Conventional Paving Mixture

Flowable Fibrous Concrete (FFC) para capas

intermedias delgadas de preservación

Lower speed applications

Slab thickness < 8 cm

10-year service life

Concrete wearing surface (Preservation)

Asphalt-concrete bond essential

Loads transmitted to substrate layers

Other sustainability enhancements:

Reflectivity, skid, air pollutant reducer

Bordelon & Roesler (2010)

FFC Proyecto de Campo (ATREL)

Ensure Good Bond with Underlying HMA

Milled and cleaned surface

Measured the FFC inlay bond with 10 cm diameter core, sheared off at greater

than 500 Nm torque (HMA overlays typically ~400 Nm)

Check Workability & Constructability of FFC

Placed 5 cm thick inlay directly from truck

Vibrated with screed and bull float finish

Joint Cracking Monitored

Slabs sawcut at spacing 1.1 to 3.4 m (4 to 11 ft)

Crack widths average from 0.4 to 1 mm wide after 20 days

Demostración en el Campo 2in (5 cm)

Recapados con Hormigón Delgado

Adherido: Resúmen Existing pavement condition assessment

Select new concrete pavement type

Define interface assumption

Available structural design methods

IDOT BCOA (Chapter 53-4.08)

ACPA (BCOA Calculator)

Pitt BCOA ME

Fibers provide excellent benefits for BCOA

Surface & subsurface drainage

Construction details essential!

141 fibers 131 fibersBordelon (2011)

Agradecimientos

Illinois Department of Transportation Illinois Center for Transportation

www.ict.illinois.edu

Randell RileyIL-ACPA

Amanda Bordelon Asst. Prof. @ University of Utah

National Concrete Pavement Technology Center Dale Harrington

American Concrete Pavement Association (ACPA)

Daniel King (2012-2015) Research Assistant, UIUC

Dr. Julie Vandenbossche University of Pittsburg

Bibliografía

Harrington, D. et al. (2012), Guidance for the Design of Concrete Overlays Using Existing Methodologies, National Concrete Pavement Technology Center, Iowa State University, Ames, IA.

Roesler, J. R., Bordelon, A., Ioannides, A. M., Beyer, M., and Wang, D. (2008), Design and Concrete Material Requirements for Ultra-Thin Whitetopping, Final Report, Illinois Center for Transportation Series No. 08-016, University of Illinois, Urbana, IL, 181 pp.

Rasmussen, R., Rogers, R., Ferragut, T. (2009), Continuously Reinforced Concrete Pavements Design and Construction Guidelines, FHWA-CRSI.

Harrington, D. et al. (2014), Guide to Concrete Overlays Sustainable Solutions for Resurfacing and Rehabilitating Existing Pavements, National Concrete Pavement Technology Center, Iowa State University, Ames, IA.

Smith, K.D., H. Yu, D. Peshkin, (2002), Portland Cement Concrete Overlays: State of the Technology Synthesis, Federal Highway Administration, Washington, DC.

Vandenbossche (2011) Development of a Design Guide for Thin and Ultrathin Concrete Overlays of Existing Asphalt Pavements, TPF-5(165)