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Recent Advances in the Design & Construction of Roller Compacted

Concrete Pavements

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AGENDA

• Roller Compacted Concrete• What is it? Where has it Been Used? and Why?

• RCC Construction Process

• Recent Advances / Changes

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ROLLER COMPACTED CONCRETE IS A ZERO SLUMP CONCRETE

With A Long History Of Good Performance On Heavy Duty Pavements

• Concrete Pavement, Placed more efficiently• No Slump, low water content• Consistency of cement treated base• Placed by asphalt pavers• Compacted with vibratory rollers• No forms• No reinforcing steel • No finishing• Normal concrete strength• Low W/C ratio = limited shrinkage cracks

Roller Compacted Concrete

Pavements

• Intermodal Port/ Freight/ Manufacturing• Ports of Houston, Long Beach, LA, Jacksonville• Central Freight – Austin, TX• Honda, Kia, BMW, Saturn – GA, TN, SC• Jack Daniel’s– Lynchburg, TN• Proctor & Gamble - PA• Lowe’s– Rome, GA• Kansas City Southern, CSX, Norfolk Southern

Historical RCC Uses

Port of Houston – 2008

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• Owner: Lowe’s• Use Type: Distribution Center• Year Built: 2012• Size: 69 Acres• Volume: 65,000 CY

Project Information

• Thickness: 7” RCC / 6” Aggregate Base• Traffic: 400 Trucks / day• Paved 30 ft wide, 150 to 180 CY/ hour• RCC paving completed in 2 months, 11

days (Calendar)• Saved $3.5 M versus asphalt with concrete

dolly strips

Additional Details

PORTS, INTERMODALS & DISTRIBUTION CENTERS ARE USING RCC FOR DURABILITY, SPEED OF CONSTRUCTION, & COST SAVINGS

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Lowe’s Distribution CenterRome, GA

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USE OF RCC PAVEMENTS IN USRCC utilization began growing in early 2000’s & is now growing at a faster rate

1975 - 1999 2000-2010 2011-2013# of Projects 71 99 172

SY 2,999,771 8,933,250 4,993,296

PAVEMENT TYPES & OWNERS ARE CHANGINGIndustrial Still Remains Largest Application Type, But Roadway are Increasing

5

12

7

27

9

24

13

2

16

5

29

57

11

Commercial Industrial Intermodal Port Roadway

# of Projects

Application Type

2011

2012

2013

34 

17 

48 

15 

42 

15 

Private Public

# of Projects

Owner Type

2011

2012

2013

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EAST WETLANDS HIKE TRAILYuma, AZ

• Owner: City of Yuma• Use Type: Trail• Year Built: 2013• Thickness: 5” RCC / Compacted

Subgrade• Quantity: 1,700 CY

Pavement Design

Information

• City Park, environmentally sensitive area

• Did not want Asphalt due to hydrocarbons

• Lacked funds for conventional concrete

• RCC made it feasible

Additional Details

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LAMESA DRIVEMIDLAND, TX

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OVER THE PAST 10 YEARS, DOT’S HAVE PAVED SHOULDERS & SURFACE ROADS USING RCC

I-85 Interchange – Lagrange, GA SR 6 – Powder Springs, GA

US 78 – Aiken, SC

I 285 – Atlanta, GA

I 385 - Greenville, SC I 75 – Tift, GA

South Carolina DOT ProjectsUS 21 Greystone

BlvdUS 25 SC 5

New StateRoad

S. BeltlineBlvd

SC 9

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I-285 SHOULDER REPLACEMENTAtlanta, GA

•35 Lane Miles of 10’ Shoulder•38500 CY of material placed•Material placed on weekends only

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ADDITIONAL PROJECTS COMPLETED BY GDOT

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ADDITIONAL PROJECTS COMPLETED BY GDOT

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• Owner: South Carolina DOT• Use Type: US Highway • Year Built: 2009• Thickness: Milled 10” asphalt

Placed 10” RCC• Traffic: 6000 ADT, 4 lanes• Speed: 45 mph

Pavement Design

Information

• Replaced 27,500 SY in 15 days• Placed 10” RCC in 1 lift• All milled areas were paved within same

day• Maintained 1 lane open in each direction

• Transverse Joints : 20 ft, early entry saw cut within 3 hours

• Traffic re-opened within 24 hours

Additional Details

Richland Ave (US 78)Aiken, SC - 2009

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RICHLAND AV. (US 78) AIKEN, SCCompleted Project

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AGENDA

• Roller Compacted Concrete• What is it? Where has it Been Used? and Why?

• RCC Construction Process

• Recent Advances

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THE FINAL SURFACE TYPE WILL DICTATE THE NECESSARY TECHNIQUES & EQUIPMENT NEEDED TO BE SUCCESSFUL

Natural RCC Diamond Ground RCC Asphalt

• Speed Limit < 35 mph• Ports• Distribution centers• Industrial yards• Residential roads• Parking lots

• Speed Limit > 35 mph• Collector / Arterial local roads• Highway Shoulders• State routes

• Any pavement type

• Lowest Cost• Most sensitive to contractor

skill level• Least smooth• “Asphalt” appearance

• Medium cost increase• Increased construction time• Improved smoothness, skid

resistance• Reduced noise

• Highest cost• Increased construction time• Least sensitive to contractor

skill level• Improved smoothness, skid

resistance

App

licat

ions

Fact

ors

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THE FINAL SURFACE TYPE DICTATES THE NECESSARY TECHNIQUES & EQUIPMENT NEEDED TO BE SUCCESSFUL

Natural RCC Diamond Ground RCC Asphalt

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THE SURFACE APPEARANCE AND TEXTURE OF RCC IS SIMILAR TO ASPHALT PAVEMENT

HMARCCPCC

• Similar appearance & texture as asphalt only light grey instead of black

• Surface texture depends on aggregate gradation and paste content

• Diamond ground RCC is similar to diamond ground concrete

• Trowelled RCC similar appearance as conventional concrete

Diamond Ground RCCDiamond Ground Conventional Concrete

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RCC MIX DESIGN USES SAME MATERIALS AS CONVENTIONAL CONCRETE, HOWEVER IN DIFFERENT COMBINATIONS

Achieves Similar or Better Engineering Properties Than Conventional Concrete

Typical Engineering Properties

Conventional (psi)

RCC(psi)

Compressive Strength 3,000 - 5,000 4,000 -10,000

Flexural Strength (MOR)

500 – 700 500 - 1,000

Elastic Modulus 3.0 – 5.0 million

3.0 – 5.5 million

15

47

30

712

36

46

3

0

10

20

30

40

50

60

Cement + FA Coarse Agg Fine Agg Water

% T

otal

Wei

ght

Typical Mix Design

Roller Compacted Concrete

Conventional Concrete

Conventional Concrete RCC

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MIXTURE DESIGN PROCEDUREStep 1: Chose well – graded aggregates

• Most important aspect of mix design (85% of mixture)• Selection based on gradation test results of available aggregates• Quantity of aggregate sources depends on # of aggregate bins at production plant• Impacts stability, workability, compactibility, segregation potential, and strength plus everything else• Need to achieve a balance of angularity and surface appearance

• Rounded aggregates increase workability but reduce stability• Typically prefer crushed coarse aggregate and natural sand

• Maximum top size is ¾”, recently began using as small as ½”

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MIXTURE DESIGN EXAMPLE

Step 2: Evaluate Combined Gradation

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

100.0

Perc

ent P

assi

ng (%

)

Sieve Size

RCC

Spec Upper Limit

Spec Lower Limit

1/2 in Power 45

3/4 in Power 45

1 in Power 45

3/4"1/2"3/8"# 4#16#100#200 1"

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MIXTURE DESIGN PROCEDURE

Step 3: Develop moisture – density relationship plots• Minimum 450 lbs cement / CY• 12% Type I Portland cement is selected for the

first trial batch• Based % on weight, so make enough and do

not worry about volumes yet• Mix the cement dry, and then add water

(ASTM D1557)

• Perform a modified Proctor test at the selected cement content

• Construct moisture-density relationship curve (Use spreadsheet)

• Determine Maximum Dry Density (MDD) and Optimum Moisture Content (OMC)

Opt

imum

Moi

stur

e

Maximum Dry Density

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MIXTURE DESIGN EXAMPLE

Develop Mix Volumetrics

145.0152.85.4%

11.5%11.5%0.0%

205525

Batch Size (CF) 27

Batch Weight (lbs/CY)

Bulk Specific Gravity (OD)

Absolute Volume (CF)

450 3.150 2.2890 2.350 0.000

693 2.650 4.1911906 2.630 11.612866 2.620 5.299211 1.000 3.388

Soil Mechanics

Mix Quantities

Target Aggregate #3 %

Target Coarse Aggregate %Target Fine Aggregate%

% Fly Ash (of cement replace)

% Cementitious

Total Water content (lbs)

Fine AggregateIntermediate Aggregate

Coarse Aggregate

CementFly Ash

Max Wet Density (lbs/CF)Optimum % Moisture

Ingredient

% Cement

Max Dry Density (lbs/CF)Mix Weight Per CY

Water Weight = (152.8-145.0) x 27

Total Dry Materials = 145.0 x 271. Select Cement content2. CA = (Total Dry-cement) x % Target

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MIXTURE DESIGN PROCEDUREStep 4: Cast samples to measure compressive strength

(ASTM C 1435)• Calculate trial mix proportions• Batch RCC materials

– Maintain percent Optimum Moisture Content as determined in step 3

– Use varying cementitious contents such as 10, 12 and 14 percent

• Make compressive strength test cylinders for each cement content

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Intended Goals of the Research• Increase haul time while maintaining workability• Retain moisture• Improve surface finish• Increase compressive strength• Increase density behind paver• Currently using Grace VSC500 @ 3 cwt

ADMIXTURES ARE BEING USED TO IMPROVE WORKABILITY AND INCREASE HAUL TIME

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Factors to Consider• High production rates: 50 to 300+CY / hr• Excellent mixing efficiency for dry materials• Highly consistent mix properties, • Mobile – 1 load, 1 Day Set up and calibration• Need to find good location, obtain permits• Self contained – Gen set, batch house• 2 man operation• # of Aggregates depends on Feeder system

WE RECOMMEND USING A PUGMILL MIXER DUE TO HIGH PRODUCTION RATES & EFFICIENT MIXING PROCESS

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RCC IS PLACED WITH HIGH DENSITY ASPHALT PAVERSAchieving Density & Smoothness is Critical

• High density screed (Vogele or ABG Titan)• High initial density from paver (90% - 96%)• Smoother surface due to higher initial density• Less “roll down” to achieve final density• High-production (6 to 8 ft/min)• 10 to 30 ft width• Lift thick range: 4” to 9”

High Density Paver

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ROLLERS ARE USED TO ACHIEVE DENSITY AND PROVIDE FINISH

• Initial: 10 - 12 ton static & vibratory roller• Establish roll pattern (check density a lot!)• Adjust roll pattern based on moisture content • Compact to 98% density - wet• Adjust moisture content if needed – impacts

smoothness & compaction• Finer mixes achieve density easier

• Combination, dual steel or rubber tired • Maximum weight - 6 short ton

• Remove roller marks• Once completed, keep roller off of the area

Initial Compaction Finish Rolling

Fairforest WayGreenville, SCGrape Creek Road – San Angelo, TX

Fairforest WayGreenville, SC

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• Need high density paver• Attach shoe to screed• Maximum angle 15o

• Use plate tamper to improve edge durability

• No saw cutting required• Pave adjacent lane next day• Lowest cost

• Pave for 50 minutes then move back to beginning and match original lane

• Do not compact original lane within 2 ft of edge until adjacent lane is paved

• Recommend a longitudinal saw cut• Use small loader to create fresh vertical

transverse joint• Move quickly – keep moist!• Coordination is key, avoid breakdowns

Angular Cold Joint Fresh (Hot) Joints

• Pave width of lane• Saw cut full depth early next

morning • Remove with blade & loader • Expect waste

• Reduce waste with paver shoe & plate tamper

• Pave adjacent lane and match thickness of existing lane

• Good performance, limited load transfer

Vertical Cold Joint

LONGITUDINAL JOINTS CAN BE BUILT 3 DIFFERENT WAYS

2 ft

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MANHOLES & CURBS ARE EASILY INCORPORATED INTO STREETS

• Traditional curb & gutter placed before RCC• Serves as compaction aid• Joint may need to be sealed

• Alternatively, ribbon curb can be placed• Drill & grout rebar into cold RCC• Place ribbon curb afterwards

• Plywood plate is placed on top of hole before RCC is placed

• After paving, two methods are available:• Dig RCC immediately while fresh, place

manhole and re - compact material with hand tampers

• Saw cut hardened RCC, place manhole, tie in with conventional concrete

Curb & Gutter Manholes, Inlets

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QC / QA PROCESS INCLUDES TESTING FOR DENSITY, MOISTURE CONTENT & COMPRESSIVE STRENGTH

• Tested with nuclear gage in direct mode • Test density behind paver & after roller to

establish rolling patterns to achieve density• Achieve 98% of modified proctor wet density• Nuclear gage gives general moisture

fluctuation indication - Calibrate with oven dried moisture

• Oven dried is most accurate

• Cylinders prepared with vibratory hammer according to ASTM C1435

• 3 to 4 cylinders per set• Strength timing often depends on traffic

opening (1, 3, 7, 28 days)• Cores can be obtained where density is not

being achieved

Compressive StrengthMoisture & Density

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WHEN CURED & SAW CUT RCC PERFORMANCE IMPROVES

• Applied at same rate or slightly higher than conventional concrete

• Ensure uniformity with application process• Apply as soon as possible behind roller

operation• Recommend WR Meadows 1200 to 1600• Ensures durable surface

Curing Saw Cut & Fill Joints• More aesthetically pleasing• Early entry saw very effective, shortly

following placement• Recommend sawing within 2 - 6 hours to

avoid uncontrolled cracking• Depth: 1” to 2” • Spacing: Maximum 36 times thickness

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SOME FACTORS TO CONSIDER WHEN BIDDING PROJECTS

• Volume of RCC paving on the project• Site geometry• Project phasing• Pavement thickness • Pavement width• Final surface characteristics• Traffic control• Opening to traffic• Daily working schedule

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Questions?

Leslie White, P.E.

Leslie.white@cemex.com

678-388-5807

Corey J. Zollinger, P.E.

coreyj.zollinger@cemex.com

713-722-6084