Applications & Design of RCC P tPavements

Wayne Adaska, P.E. Director, Public WorksPortland Cement Association

RCC Pavements

Introduction ApplicationsMix DesignMix DesignThickness DesignPerformancePerformance

Cement-Based Pavement M t i lMaterials

Roller-Compacted Conventional

tent

pConcrete Concrete

PerviousConcrete

nt C

ont

Soil-Cement

Concrete

Cem

en

Flowable Fill

Water Content

Definition

“R ll C t d C t (RCC) i l“Roller-Compacted Concrete (RCC) is a no-slump concrete that is compacted by vibratory rollers.”

Zero slump (consistency of dense graded aggr.)No formsNo formsNo reinforcing steel No finishinggConsolidated with vibratory rollers

Concrete pavement placed in a different way!

Benefits of RCCPBenefits of RCCP

Fast construction with minimum laborFast construction with minimum laborHigh load carrying abilityEli i t tti & k b dEliminates rutting & spans weak subgradesEarly strength gainDurableLow maintenanceLow maintenanceLight surface reduces lighting requirementsE i lEconomical

Project ConsiderationsProject Considerations

P j t iProject sizeSite geometryLoading characteristicsEnd useClientClient expectations

Surface AppearanceSurface Appearance

Not as smooth as conventional concreteImportant to precognize differenceSimilar appearanceSimilar appearance to asphalt only light grey instead of blackgrey instead of black

Engineering Propertiesg g p

Compressive strength (f’c)–4,000 to 10,000 psi

Flexural strength (MR)–500 to 1,000 psi500 to 1,000 psi–MR = C(f’c)1/2 where C = 9 (up to 11)

Modulus of elasticityModulus of elasticity–3,000,000 to 5,500,000 psi

E C (f’ )1/2 h C 57 000 ( t 67 000)–E = CE(f’c)1/2 where CE = 57,000 (up to 67,000)

Compaction Very ImportantCompaction Very Important

ApplicationsApplications

Log Sort YardsLog Sort Yards

Vancouver Island, BC, 1978

Military Facilities

Ft. Lewis, WA ,1986 Ft. Carsons, CO, 2008

Ft. Drum, NY, 1990

Intermodal FacilitiesIntermodal Facilities

Central Station, Detroit, MI

Burlington Northern, Denver, CO

CN Intermodal Yard, CalgaryCN Intermodal Yard, Calgary

RCC decreased t k it ti f truck wait time from

8 to 2 hours

Unsurfaced aggregateis difficult to maneuverand presents safetyand presents safetyhazard

Port Terminals

Port of Houston, TX, 2007

Norfolk International Terminal, VA, 2006

, ,

Distribution CentersDistribution Centers

18 acre distributioncenter in Austin, TX

10 years after construction

Warehouse FacilitiesWarehouse Facilities

RCC sed as orking

Warehouse, Appleton, WI

RCC used as working platform for cast-in-place

tilt-up walls

Parking Areas

207 acres Honda facility, AL 2001

134 ki f ili134 acre parking facility at Saturn plant, TN, 1988

Streets & Interchanges

I t ti l tIntersection replacement Calgary, AB

Residential streetResidential street Columbus, OH

Highway Shoulders

I-285 HighwayAtlanta, GA

Dams

C.E. Siegrist Dam, PA

Overtopping ProtectionOvertopping Protection

Lake Lanape, PABoney Falls Dam, MI

Waste Handling Facilities

25 acre sludge drying basins in Austin, TX

5 acre composting yard near Toronto

1 acre composting yard in North Augusta, SC

Mixture DesignMixture Design

Mixture DesignMixture Design

Modification needed in conventionalModification needed in conventional concrete mixture procedures

N t i t i d–Not air-entrained–Zero (negative) slump–Lower paste content–Higher fines content (2 to 6%)–Nominal max. size aggregate +/- 5/8 in.

Conventional Concrete vs RCCConventional Concrete vs RCC

Mixture DesignMixture Design

Dry enough to support vibratory rollerWet enough to permit adequate distribution of paste

Proportioning MethodsProportioning Methods

S l th d il blSeveral methods available:

–Concrete consistency testsConcrete consistency tests

–Soil compaction method

–Optimal paste volume method

–Solid suspensions model

Always allow time and money for field trialAlways allow time and money for field trial

Aggregate SelectionAggregate Selection

Aggregate selection very importantResponsible for mix workability, segregation, ease of consolidationPre-blended or stored separately

Aggregate SelectionAggregate SelectionSelect a sound, well-graded aggregate

– For stability under vibratory roller, aggregate interlock for load transfer, flexural strength

Highway base course asphalt or concreteHighway base course, asphalt or concrete aggregates can be used5/8” maximum size aggregate5/8 maximum size aggregate

– For smooth surface, less segregation

Higher fines contentHigher fines content – Provides additional paste to fill voids and maintain tight

surface– Avoid plastic (clay) fines

Aggregate GradationAggregate Gradation

1” 3/8” #4 #16 #2005/8”

80%

100%1 3/8 #4 #16 #2005/8

Pas

sing

60%

80%

RCCC i l

Per

cent

20%

40%RCCConventional

0 010 11101000%

20%

0.010.1110100

Sieve Size (mm)

Optimum Combined Gradation (Shilstone Method)

The Coarseness Factor Chart provides on overview of the mixtureoverview of the mixture

The 0.45 Power Chart shows a trend

Percent of aggregate retained on individual sieves (8/18 rule) shows detailsindividual sieves (8/18 rule) shows details

Aggregate GradationAggregate Gradation

Sieve Size Percent Passing Actual PercentSieve Size Percent Passing Actual Percent in mm Minimum Maximum Gradation Retained1" 25 100 100 100 0.0

3/4" 19 95 100 100 0.01/2" 12.5 75 90 85.2 14.83/8" 9.5 65 85 75.0 10.23/8 9.5 65 85 75.0 10.2#4 4.75 40 60 57.0 18.0#8 2.36 25 50 43.5 13.5

#16 1 18 20 40 34 2 9 3#16 1.18 20 40 34.2 9.3#30 0.6 10 30 24.3 9.9#50 0.3 7 20 10.6 13.7#100 0.15 5 15 2.1 8.5#200 0.075 2 6 0.7 1.4

*

Coarseness Factor (CF) = % retained on 3/8 in. ÷ % retained on # 8 sieve x 100

Workability Factor (WF) = % passing #8 sieve + [ 2.5 x (lb/yd3 of cementitious material – 564) / 94]

( )25% /56.5% x 100 = 44.2%

43.5% pass #8 sieve; 2.5 (500-564)/94 = -1.7; 43.5 -1.7 = 41.8%

Soil Compaction MethodSoil Compaction Method

Determine moisture content–Construct moisture/density curveConstruct moisture/density curve–Modified proctor ASTM D1557

A di t t t (–Assume a median cement content (e.g. 500 pcy)

Moisture-Density RelationshipMoisture Density Relationship

143

144

cf)

142

143

nsit

y (l

b/

140

141

Dry

De

140

2% 3% 4% 5% 6% 7% 8%

Moisture Content

High Density Ensures Superior StrengthHigh Density Ensures Superior Strength

6,000 800

5,000

ngth

(psi

)

600

ngth

(psi

)

4,000

ssiv

e St

ren

nsile

Stre

n

Compressive Strength

3,000

Com

pres 400

Split

Ten

Tensile Strength

2,00094% 96% 98% 100%

Wet Density (% Modified Proctor)

200

y (% )

Soil Compaction MethodSoil Compaction Method

D t i titi t i l t tDetermine cementitious materials content–Use optimum moisture content–Run cement series

• e.g., 11%, 13%, 15%, 17%

–Select cement content which yields appropriate strength.

Strength vs Cement ContentStrength vs. Cement Content

6,000

6,500

sive

725

697

5 000

5,500

,

Com

pres

sng

th (

psi)

667

636

4,500

5,000

28

-Day

CS

tren 636

603

5694,00010% 12% 14% 16% 18%

Cement Content

569

Admixtures

Fly ash, slag, silica fume have been used

Retarders can be used to increase working time

W t d d t i k bilitWater reducers used to increase workability

Air entrainment very difficult in the field, but y ,– Experience has shown RCC can be made F/T resistant

Fibers seldom usedFibers seldom used – Increased difficulty with mixing & compaction

Sample RCC Mix Designs

Port of TacomaUnits

Port of Tacoma Intermodal Yard CTL Mix Canada Mix

Coarse Aggregate lb/cy 1,700 2,106 2,210Fine Aggregate lb/cy 1,700 1,378 1,338

MSA in 5/8 3/4 1/2% Finer Than #200 % 3 - 7 2 1

Cement lb/cy 450 504 470Fl A h lb/ 100 0 36 ( ili f )Fly Ash lb/cy 100 0 36 (silica fume)Water lb/cy 257 211 172

Admixture oz/cwt none none 5 (WR)w/c ratio - 0 47 0 42 0 34w/c ratio - 0.47 0.42 0.34

Unit Weight lb/cy 154.3 152.0 153.1Compressive: 3 day psi 1,810 5,460 -Compressive: 28 day psi 6,050 7,900 -

Flexural: 3 day psi 525 690 1,205Flexural: 28 day psi 770 900 1,640

ThicknessDesign

Thickness Design of RCC Pavements

Follows rigid pavement design methodsPlain undoweled unreinforced concretePlain, undoweled, unreinforced concrete pavementThi k ff t d b fl l t thThickness affected by flexural strength and fatigue behaviorPCA’s Structural Design of RCC for Industrial PavementsPCA RCC-PAVE Program

Slab Tensile Stress is CriticalSlab Tensile Stress is Critical

Stress is affected by:• Load• Load• Tire pressure, spacing• Slab thickness

S bb t• Subbase support• Concrete stiffness

Design AssumptionsDesign Assumptions

Interior loadingInterior loadingMonolithic slab action for multi-layer

t ticonstructionLoad transfer across joints/cracksConservatism:–Design curve below fatigue testsDesign curve below fatigue tests–Strength gain with age

Fatigue FactorFatigue Factor

Fatigue: Material failure which occursFatigue: Material failure which occurs when it ruptures under continued repetitions of loads that cause stressrepetitions of loads that cause stress less than material strengthFl l (t il ) t th t l fFlexural (tensile) strength controls for pavements.Stress ratio: Flexural stress/strength

Engineering PropertiesFatigue

1

0.8

s R

atio

, SR

50%95%Conv Design

0.6

Stre

ss

gRCC Design

0.41.0E+01 1.0E+02 1.0E+03 1.0E+04 1.0E+05 1.0E+06 1.0E+07

Load Applications to Failure, Npp

Thickness Design ProcedureThickness Design Procedure

Support strength of subgrade (k value)Vehicle characteristics–Wheel loads–Wheel spacing–Wheel spacing–Tire characteristics

Number of load repetitions during design life–Number of load repetitions during design lifeFlexural strengthModulus of elasticity

Thickness Design ProcedureThickness Design Procedure

Subgrade SupportSubgrade Support–“k” value in units of pci

U l t l d t t ti t d–Use plate load test, or estimated relationships

V hi l L dVehicle Loads–Normally, heaviest wheel load controls–Contact area: wheel load/tire pressure–Wheel spacing: per manufacturerp g p

Thickness Design ProcedureThickness Design Procedure

Typically 90-day flexural strength used

Allowable pavement stress < Design pavement stresspavement stress

Allow stress = (stress ratio) x (flex str)Allow stress = (stress ratio) x (flex str)

Design for Stress RatioDesign for Stress Ratio

Stress Ratio = critical applied tensile stressModulus of Rupture (flexural strength)Modulus of Rupture (flexural strength)

where:

critical applied stress is the maximum tensile stress at the bottom of the concrete pavement slab, and

Modulus of Rupture is the tensile strength of a concreteModulus of Rupture is the tensile strength of a concrete beam tested using 1/3-point loading at 90 days

Design Example

Design ExampleContainer Carrier, Single WheelAxle load: 52 000 psi Wheel load: 26 000 psiAxle load: 52,000 psi, Wheel load: 26,000 psiTire pressure: 100 psiTi t t 26 000/100 260 iTire contact area: 26,000/100 = 260 sq inSubgrade modulus: 100 pciRCC flex str: 700 psiRCC modulus of elasticity: 4,000,000 psiy pLoad frequency: 20 reps/dayDesign life: 20 years, therefore;Design life: 20 years, therefore;20 yr x 365 x 20 reps/day = 146,000 total reps

0.45 146 K

Design ExampleDesign Example

Subgrade Strength

Flex Strength Total Stress ThicknessStrength

(pcf)Strength

(psi)Total Reps

Stress Ratio

Thickness (in.)

100 700 146,000 0.45 10100 900 146,000 0.45 9300 700 146,000 0.45 9.5100 700 Unlimited 0 41 11100 700 Unlimited 0.41 11100 500 146,000 0.45 12.5100 700 Unlimited 0.41 13.5

RCC - PAVE Computer Program

PerformancePerformance

Freeze-Thaw DurabilityField performance excellent, although not air entrainedMinor surface paste (1/16”) erodes, then stabilizesstabilizesRCC results variable under ASTM C666 (F/T) and C672 (Deicer scaling)and C672 (Deicer scaling)Tests appear to be too severe based on

t l iactual experienceDurability tests used for masonry concrete and precast units possibly more appropriate

Freeze-Thaw Durability TestsFreeze Thaw Durability Tests

Conventional Concrete (ASTM C666)

Brick and Structural Clay Tile (ASTM C67)Brick and Structural Clay Tile (ASTM C67)

Concrete Paving Units (ASTM C936)

Concrete Masonry Units (ASTM C1262)

Soil-Cement (ASTM D560)

Freeze-Thaw Durability

Roller Compacted ConcreteRoller-Compacted Concrete Pavements–

A Study of Long Term PerformancePerformance

PCA Research Report RP 366PCA Research Report RP 3661999

Research ParametersResearch Parameters

P j t d i f 3 t 20Projects ranged in age from 3 to 20 yearsVariety of applications and loading conditionsDifferent climatic conditionsTotal of 34 projects inspected in both U.S. and Canadaand CanadaSynopsis of 18 projects included in report

Surface Texture & ConditionSurface Texture & Condition

Thin layer of surface fines

llnormally worn away in first 2-3 yearsStabilizes thereafterStabilizes thereafterCoarse aggregate exposed, butexposed, but embeddedProvides traction

BN Yard, Denver - 13 years

Surface Texture & Condition

Some patches of more extensive surfaceextensive surface erosion occur which are likely due toare likely due to aggregate segregation

Ft. Drum, NY - 11 years

Surface will vary inSurface will vary in texture

BN Yard, Denver - 13 years

Joints/Cracks

RCC cracks betweenRCC cracks between 15 ft to 60 ftCracks are transverse to pavement directionLongitudinal cracks at paving lanesIf RCC surfacedIf RCC surfaced, cracks will reflect

112th St., Edmonton, ABCrack through asphalt

Joints/Cracks

Cracks have remained very narrow/tighty gMost cracks not sealedSome raveling especially g p yalong longitudinal jointsVirtually no faulting

Ft. Drum, NY - 11 yearsy g

found. Good apparent load transferVirtually no maintenance for most pavements

O’Hare Reservoir, IL - 3 years

SurfacingCentral Freight

Hornsby Bendy

Brownsville

More Information

www.cement.org/pavements

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