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Internal Curing of Concrete Pavements
Thursday, February 16, 2017 2:00-3:30 PM ET
TRB WEBINAR PROGRAM
The Transportation Research Board has met the standards and
requirements of the Registered Continuing Education Providers Program.
Credit earned on completion of this program will be reported to RCEP. A
certificate of completion will be issued to participants that have registered
and attended the entire session. As such, it does not include content that
may be deemed or construed to be an approval or endorsement by RCEP.
Purpose
Discuss the internal curing of pavements, the process by which the curing water comes from the aggregates within the concrete. The presenters will discuss the concepts of internal curing, practical applications, mixture design, construction, and quality control.
Learning Objectives
At the end of this webinar, you will be able to: • Understand the fundamentals of internally cured concrete
pavements and their applications. • Understand the materials used for internally cured pavement
applications including mixture design and properties of IC concrete. • Understand the process of construction of internally cured concrete
pavements.
PDH Certificate Information
• This webinar is valued at 1.5 Professional Development Hours (PDH)
• Instructions on retrieving your certificate will be found in your webinar reminder and follow-up emails
• You must register and attend as an individual to receive a PDH certificate
• TRB will report your hours within one week • Questions? Contact Reggie Gillum at [email protected]
All Attendees Are Muted
Questions and Answers
• Please type your questions into your webinar control panel
• We will read your questions out loud, and answer as many as time allows
Can’t locate the GoToWebinar Control Panel?
Having Trouble Logging On?
Panelists Presentations
http://onlinepubs.trb.org/onlinepubs/webinars/170216.pdf
After the webinar, you will receive a follow-up email
containing a link to the recording
Today’s Participants
• Sam Tyson, Federal Highway Administration, [email protected]
• Jason Weiss, Oregon State University, [email protected]
• Dennis Morian, Quality Engineering Solutions, [email protected]
• Steven Gillen, Illinois Tollway, [email protected]
Get Involved with TRB • Getting involved is free! • Join a Standing Committee (http://bit.ly/2jYRrF6)
– AFD50 (Design and Rehabilitation of Concrete Pavements), AFH50 (Concrete Pavement Construction and Rehabilitation), and AFD70 (Pavement Rehabilitation)
• Become a Friend of a Committee (http://bit.ly/TRBcommittees) – Best way to become a member – Ultimate networking opportunity
• For more information: www.mytrb.com – Create your account – Update your profile
97th TRB Annual Meeting: January 7-11, 2018
Internal Curing for Concrete Pavements
Transportation Research Board Webinar 2:00 PM – 3:30 PM
Thursday, February 16, 2017
Sam Tyson, P.E. Concrete Pavement Engineer
FHWA Office of Asset Management, Pavements, and Construction
Internal Curing for Concrete Pavements
TRB Committee/Webinar Sponsors – • AFD50 – Design and Rehabilitation of
Concrete Pavements • AFH50 – Concrete Pavement Construction
and Rehabilitation
Internal Curing for Concrete Pavements
Background: FHWA Publication – Internal Curing for Concrete Pavements FHWA-HIF-16-006, July 2016 https://www.fhwa.dot.gov/pavement/concrete/pubs/hif16006.pdf
and numerous references cited in that document.
Internal Curing for Concrete Pavements
Jason Weiss, Oregon State University
Dennis Morian, Quality Engineering Solutions
Steven Gillen, Illinois Tollway
Internal Curing for Concrete Pavements
• Introduction and Background • Mixture Design • Quality Control • Emerging Potential Benefits • Pavement Applications
Samuel S. Tyson, P.E. Concrete Pavement Engineer
Office of Asset Management, Pavements, and Construction Federal Highway Administration
1200 New Jersey Avenue, S.E. – E73-440 Washington, DC 20590
E-mail: [email protected]
Phone: 202-366-1326
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 1 of 36 1 1
INNOVATIVE SOLUTIONS TO COMPLEX PROBLEMS
Internal Curing for Concrete Pavements
Jason Weiss, Dennis Morian, Shree Rao
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 2 of 36
Associated Technical Brief
• This presentation was developed to accompany FHWA Tech Brief HIF-16-006
• It will discuss concepts of IC for concrete pavements including: mixture design, construction, and quality control
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 3 of 36
Outline for Today’s Talk
• We want to discuss what internal curing is and where Internal Curing may have applications
• Mixture Design • Quality Control • Emerging Potential Benefits
– Reduce Joint Damage – Reduce ASR Damage (dilution/accomodation) – Reduced Built in Stress and Curing Times
• Pavement Applications ASR = Alkali Silica Reaction
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 4 of 36
What is Internal Curing?
• Internal curing water is simply water curing where the water is provided from inside the concrete
• In the US this is typically done currently by placing water inside the porous LWA
• This can also be done using superabsorbent polymers (SAP), absorptive fibers, or recycled concrete
• However currently these technologies are not as readily available for use in pavements as is fine LWA
LWA = Lightweight Aggregate SAP = Superabsorbent Polymer
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 5 of 36
External and Internal Curing
Cast
ro e
t al.
2009
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 6 of 36
Where Has Internal Curing Been Used Water Tanks - Bates et al. 2012 Bridge Decks - DiBella et al. 2011
Pavements - Friggle et al. 2011 Patches - Barrett et al. 2014
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 7 of 36
Outline for Today’s Talk
• We want to discuss where Internal Curing may have applications
• Mixture Design • Quality Control • Emerging Potential Benefits
– Potential to Reduce Joint Damage – Potential to Reduce ASR Damage (dilution/accom.) – Reduced Built in Stress and Curing Times
• Pavement Applications
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 8 of 36
How Is IC Concrete Made
• Except for LWA, IC concrete mixture design generally is identical to that of conventional concrete with similar air content, water content, and coarse aggregate content.
• Currently, IC in North America is typically achieved by replacing a portion of the conventional fine aggregate (i.e., sand) with a pre- wetted lightweight fine aggregate. IC = Internal Curing
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 9 of 36
Outline for Today’s Talk
• We want to discuss where Internal Curing may have applications for
• Mixture Design • Quality Control • Emerging Potential Benefits
– Reduce Joint Damage – Reduce ASR Damage (dilution/accomodation) – Reduced Built in Stress and Curing Times
• Pavement Applications
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 10 of 36
Mixture Design for Internal Curing
• similarities and differences between the design of a conventional 6-bag mixture (water-to-cement ratio of 0.36 and 6 percent air) and an IC mixture
• assumes 15% absorption of the FLWA
• 7 lb of IC water for every 100 lb of cementititious materials.
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 11 of 36
Simple Mixture Proportioning
• Convert an existing paving mixture or a bridge deck mixture to an IC Mixture
Materials Weight SG (SSD) Volume, ft3Cement 564 3.15 2.869GGBFS 115 2.99 0.616Fly Ash 0 2.64 0.000
Silica Fume 25 2.2 0.182Sand 591 2.623 3.613
Lightweight Aggregate 413 1.750 3.780Coarse Aggregate 1 1700 2.763 9.860Coarse Aggregate 2 0 2.763 0.000
Water 258 1 4.135Air 0 0 1.755
Σ 3666 - 26.810
IC Mixture Design
LWA Absorption: 15.0%LWA Desorption: 85.0%
LWA Specific Gravity 1.750Cement Factor 704
Chemical Shrinkage: 0.065Degree of Hydration 1
SSD LWA Replacement 413SSD Sand Replaced 619
Internal Curing Properties
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 12 of 36
Outline for Today’s Talk
• We want to discuss where Internal Curing may have applications for
• Mixture Design • Quality Control • Emerging Benefits
– Potential to Reduce Joint Damage – Potential to Reduce ASR Damage (dilution/accom.) – Reduced Built in Stress and Curing Times
• Pavement Applications
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 13 of 36
Measuring Aggregate Properties
• Aggregate Moisture • Surface Moisture • Aggregate Absorp. • Specific Gravity
(Relative Density) • Desorption
• Spreadsheet and
Step by Step Process (Miller et al 2014)
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 14 of 36
Outline for Today’s Talk
• We want to discuss where Internal Curing may have applications for
• Mixture Design • Quality Control • Emerging Potential Benefits
– Reduce Joint Damage – Reduce ASR Damage (dilution/accomodation) – Reduced Built in Stress and Curing Times
• Pavement Applications
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 15 of 36
Joint Damage and the Role of IC • Concrete pavement joints damaged by salt
3Ca(OH)2 + CaCl2 + 12H2O CaCl2·3Ca(OH)2·12H2O Calcium Oxychloride
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 16 of 36
IC and Calcium Hydroxide (CaOH2; CH)
• Ca(OH)2 forms in solution and deposits in/on aggregate • Ca(OH)2 deposits on aggregate surfaces (few to 20 µm)
as stage III begins (before set) • Ca(OH)2 will react with deicing salt
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 17 of 36
Reaction of SCM and the Role of IC
• IC provides additional water that can help to increase the cement that hydrates as well as the SCM that hydrates
• As such, IC will reduce (Ca(OH)2) and reduce joint damage
0.25 0.30 0.35 0.40 0.45 0.50w/c
Internal CuringSealed
0.4
0.5
0.6
0.7
Deg
ree
of H
ydra
tion
at 7
2 h
(Hea
t / M
axim
um th
eore
tical
hea
t)
Castro et al. 2010
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 18 of 36
Outline for Today’s Talk
• We want to discuss where Internal Curing may have applications for
• Mixture Design • Quality Control • Emerging Potential Benefits
– Reduce Joint Damage – Reduce ASR Damage (dilution/accomodation) – Reduced Built in Stress and Curing Times
• Pavement Applications
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 19 of 36
Alkali Silica Reaction (ASR) and IC • Internal Curing Benefits –
– decreases porosity through hydration, – accommodation space allows gel without pressure, – dilution (replaces reactive aggregates)
• Internal Curing Disadvantages – – Higher RH/moisture
which would enable more ASR reaction to occur
RH = Relative Humidity
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 20 of 36
Alkali Silica Reaction (ASR) and IC • Reactive (R) – Most reactive and expansive • Non Reactive Aggregate Replacement at 15 & 28% (m) –
Reduces expansion due to dilution • Internal Curing – LWA Replacement at 15 & 28% % (N)) –
more effective even than non reactive aggregate LWA provides space for expansive gel to form
• 15% replacement is CS volume Sh
in e
t al.
2010
CS = Chemical Shrinkage
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 21 of 36
Outline for Today’s Talk
• We want to discuss where Internal Curing may have applications for
• Mixture Design • Quality Control • Emerging Potential Benefits
– Reduce Joint Damage – Reduce ASR Damage (dilution/accomodation) – Reduced Built in Stress and Curing Times
• Pavement Applications
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 22 of 36
Benefits of IC - Thermal • IC makes concrete less susceptible to thermal
cracking, as “built-in” stress is reduced
Schlitter et al. 2010
Plain Concrete IC Concrete
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 23 of 36
Patching and Full Depth Panel Repair
• Field trials performed in Indiana in 2014 used IC with expanded slag aggregate in high early strength, full-depth concrete pavement patches
• Application of IC in the high early-strength patches provided a concrete with two distinct benefits when compared with conventional concrete: 1) reduced built-in stress and cracking caused by
the restraint of shrinkage, and 2) increased water curing (from inside the concrete)
after the patches are covered with curing compound and opened to traffic. 23
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 24 of 36
Patching and Full Depth Panel Repair
24
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 25 of 36
Outline for Today’s Talk
• We want to discuss where Internal Curing may have applications for
• Mixture Design • Quality Control • Emerging Potential Benefits
– Reduce Joint Damage – Reduce ASR Damage (dilution/accomodation) – Reduced Built in Stress and Curing Times
• Pavement Applications
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 26 of 36
CRCP Pavements
• Potential reduction in shrinkage, modulus and curling • May result in thinner sections or increased mechanical
performance and fatigue capacity • Initial crack spacing was approximately 3x longer than
those developed in conventional sections • Longer term monitoring has shown that this difference
in crack spacing decreases over time until the spacing is on the order of 20 to 30 percent longer than that in conventional concrete.
• Cracks in internally cured concrete remain tighter than those in conventional concrete
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 27 of 36
JPCP Pavements
• IC may improve durability by reducing moisture loss and improving hydration, from the extended moisture supply provided.
• IC reduces early age shrinkage and associated plastic shrinkage cracking
• Another potential benefit to jointed pavements is a reduction in upward slab curling resulting from internal slab moisture gradients and stresses locked in at the time of set resulting from temperature gradients during curing.
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 28 of 36
Applications of IC in Pavements 1
• A number of IC pavement have been placed, primarily in the Dallas-Fort Worth area using a relatively small substitution of intermediate aggregate sizes with lightweight aggregate.
• A residential subdivision in south Fort Worth, Windsor Park, constructed in 2006-2007. A survey after 8 years in service identified no significant longitudinal or transverse cracking, plastic shrinking cracking, spalling, or other defects. In general, the pavement was in excellent condition.
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 29 of 36
Applications of IC in Pavements 2
• 1,400-foot section of CRCP of State Highway 121 near Dallas in 2006
• Initially the cracks in the IC had a larger spacing
• After several years, the crack spacing was similar to that of the conventional sections; however, the cracks remained much tighter
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 30 of 36
Applications of IC in Pavements 3
• A 360-acre Union Pacific intermodal terminal located 12 miles from downtown Dallas within the city limits of Hutchins and Wilmer
• Minor joint spalls and limited cracking have been
observed. Performance has been similar to the conventional sections, with both in excellent condition.
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 31 of 36
Applications of IC in Pavements 4
• A residential subdivision in north Fort Worth, Alexandria Meadows North, constructed in 2006-2007.
• Project contained streets both with and without internally cured concrete.
• A field survey revealed both the internally cured concrete and conventional pavement sections were in excellent condition, with very limited cracking.
• No slab curl was identified.
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 32 of 36
Summary - 1 • ICC has been successfully used in full-scale bridge
decks and concrete pavement patching projects. • ICC has similar workability, strength and mechanical
property development, reduced stress development and cracking, and similar or improved durability when compared with conventional concrete.
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 33 of 36
Summary - 2
• Aspects of proportioning and quality control – Excel worksheets for modifying a concrete mixture and for
quantifying the properties of the aggregate – Centrifuge test has substantial benefits in obtaining
surface dry conditions – Prewetting may need to be modified for IC pavements
due to the volume of material used
• Emerging Benefits for IC in pavement – Potential to reduce joint damage caused by salt – Potential to reduce ASR damage (dilution/accommodation) – Reduced curing times
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 34 of 36
Summary - 3
• Field trials examining the use of ICC in continuously reinforced concrete pavement, white topping, and jointed plain concrete pavements.
• Specific improvements hypothesized include: – reduced shrinkage, fewer and tighter cracks, – improved fatigue resistance, and – reduced slab curling/warping
• Pavement ME Design suggests that the performance of ICC pavements should be superior to conventional concrete pavements, resulting in improved life cycle
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 35 of 36
Additional Resources http://cce.oregonstate.edu/internalcuring
Internal Curing for Pavements Prepared by Jason Weiss, Dennis Morian and Shree Rao Slide 36 of 36
Acknowledgements and Disclaimer
• These slides were developed as a part of a series for the ARA by Jason Weiss and Dennis Morian.
• These materials are provided as general information and do not constitute legal or other professional advise.
• Any use of this information in the design or selection of materials for practice should be approved by the project owner and engineering-of-record.
Internal Curing of Concrete Pavements at the Illinois Tollway
Steve Gillen, Tollway Materials Manager February 16, 2017
About the Illinois Tollway
292-mile system comprised of five tollways
Opened in 1958 as a bypass around Chicago to connect Indiana and Wisconsin
Carries more than 1.6 million vehicles per day
User-fee system • Only customers who use the
Tollway pay for the Tollway • No state or federal tax dollars
used for maintenance and operations
2 Presented by Steve Gillen on February 16, 2017
Internal Curing at the Illinois Tollway
Bridge decks since 2013
Presented by Steve Gillen on February 16, 2017 3
Pavement since 2016
Bridge Decks
Proportioning • Performance-related mix design special provision
• Time to cracking greater than or equal to 28 days according to ASTM C 1581
• Reduced early age shrinkage
Field performance • No placement or finishing issues • Significantly reduced early age cracking in bridge decks
Presented by Steve Gillen on February 16, 2017 4
Pavement
Ongoing research project on continuously reinforced concrete pavement (CRCP) • Collaboration between University of Illinois (Professor J. Roesler),
Oregon State University (Profesor W.J. Weiss) and Texas A&M University (Professor D. Zollinger)
• Three-year partnership (2015 to 2017)
Multi-year study with following components • Laboratory concrete material research • Innovative structural design • Construction process improvements • Field test section monitoring and evaluation
Additional partners • CMC Inc. • ESCSI Inc.
Presented by Steve Gillen on February 16, 2017 5
Laboratory Materials Research
Development of typical CRCP crack spacing and widths using internally cured (IC) concrete
Effects of IC on curling and warping of concrete
Black steel vs. epoxy-coated steel on CRCP service life especially with chloride salts
Concrete mixture improvements • Combined portland cement and supplementary cementitious
materials (SCM’s) – ternary • Mixture proportioning adjustments – optimized • Evaluate freeze-thaw damage potential
Presented by Steve Gillen on February 16, 2017 6
Innovative Structural Design
Thinner CRCP slab thickness from internal curing • Minimize crack width • Non-erodible support layers • Effects of reduced steel content • Use of sawed crack induction for better crack control
Support layer properties and erodibility • Asphalt stabilized bases vs. roller compacted cement-treated
bases • Designing erosion resistant layers from recycled materials • Hamburg Wheel Load Tracking – performance tests
Presented by Steve Gillen on February 16, 2017 7
CRCP Test Sections 2016/2017
Nine three-lane test sections to be constructed on the Illinois Route 390 Tollway under three contracts • Contract I-13-4629 (2000 feet) • Contract I-14-4642 (1000 feet) • Contract I-14-4644 (1000 feet)
Presented by Steve Gillen on February 16, 2017 8
9” WMA Shoulder
6” WMA Shoulder
6” Lean Concrete Base
4” Granular Subbase Special, thickness varies under shoulders
¼” to ½” Microsurfacing Bond Breaker
10.5” CRC Pavement, Internally Cured, 0.8% steel
Typical Section for Test Section 1A (Contract 4629)
Presented by Steve Gillen on February 16, 2017 9
Contract 1-13-4629 Construction
10
Compacting 4-inch aggregate base
Paving 4-inch and 6-inch lean
concrete base
Presented by Steve Gillen on February 16, 2017
Contract 1-13-4629 Construction
11
Paving micro-surfacing layer
Paving 2-inch warm-mix
asphalt (WMA) stabilized subbase
Presented by Steve Gillen on February 16, 2017
Contract 1-13-4629 Construction
12
Placing and tying steel
Paving CRCP with internally cured
optimized ternary concrete
Presented by Steve Gillen on February 16, 2017
Typical Section for Test Section 2A (Contract 1-14-4642)
9” WMA Shoulder
9” WMA Shoulder
2” WMA Stabilized Subbase
4” Lean Concrete Base
4” Granular Subbase Special, thickness varies under shoulders
10.5” CRC Pavement, Class TL Concrete, 0.6% steel
Presented by Steve Gillen on February 16, 2017 13
Contract 1-14-4642 Construction
14
Paving 4-inch aggregate base
Paving 4-inch lean concrete
base
Presented by Steve Gillen on February 16, 2017
Contract 1-14-4642 Construction (Control Section)
15
Paving 2-inch WMA stabilized
subbase
Placing an tying steel
Presented by Steve Gillen on February 16, 2017
Contract 1-14-4642 Construction (Control Section)
16
End treatment
Paving CRCP with standard optimized
ternary concrete
Presented by Steve Gillen on February 16, 2017
Typical Section for Test Section 3A (Contract 1-14-4644)
Two Lift 9.0” CRC Pavement, Internally Cured, 0.6% steel
3” WMA Stabilized Subbase
6” Porous Granular Subbase
9” JPCP Shoulder 9” WMA Shoulder
Capping Stone – varied thickness
Capping Stone - Varied thickness
Chemically Treated Subgrade
Single Lift 9.0” CRC Pavement, Internally Cured / Fiber Reinforced, 0.6% steel
Presented by Steve Gillen on February 16, 2017 17
Lessons Learned with Mass Production of Internally Cured Concrete for Pavements Good control of the pre-wetting of lightweight fines is critical • Central mix plant
modifications likely needed for extra feed lines
• Centrifuge testing is important • Stockpiling and pre-wetting
during production must be well planned to maintain consistency
Production rates can not be slowed with internally cured concrete for pavements
Presented by Steve Gillen on February 16, 2017 18
Preliminary Conclusions – Average Crack Spacing Observations of CRC Test Sections
Presented by Steve Gillen on February 16, 2017 19
Fibe
r
Preliminary Conclusions – Average Crack Width Observations of CRC Test Sections
Presented by Steve Gillen on February 16, 2017 20
Fibe
r
Future Direction for Internal Curing With CRC Pavements
Presented by Steve Gillen on February 16, 2017 21
Central Tri-State Tollway (I-294) Corridor
Project Limits • 95th Street to Balmoral Avenue • 22 miles
Existing Lanes • Eight lanes, four in each direction
Features • 13 interchanges • 65 bridges carrying I-294
over different features • 21 bridges over I-294 • 2 oases • 5 mainline toll plazas
THANK YOU
Presented by Steve Gillen on February 16, 2017 22