Asphalt Won’t Work for a Bridge Abutment – How to Design ... · Concrete Mix Design & Analysis...

Concrete Mix Design & Analysis 2008 Local Roads Seminar

Steve Waalkes, PEMichigan Concrete Paving Association

Asphalt WonAsphalt Won’’t Work for a Bridge t Work for a Bridge Abutment Abutment –– How to Design, How to Design, Specify, Inspect and Test Specify, Inspect and Test

ConcreteConcrete2009 Michigan County Engineers 2009 Michigan County Engineers

Workshop Workshop

Mt. Pleasant, MIMt. Pleasant, MIFebruary 19, 2009February 19, 2009

Cary T. Keller, P.E. Cary T. Keller, P.E. InstructorInstructor

Alpena Community College/World Center for Concrete TechnologyAlpena Community College/World Center for Concrete Technology

Presentation OverviewPresentation Overview

►► ConcreteConcrete’’s sustainability can make your county more s sustainability can make your county more ““greengreen””

►► The economies of concrete pavementsThe economies of concrete pavements►► The various ways that concrete pavements can be The various ways that concrete pavements can be

used in your county, including:used in your county, including:ӨӨ New ConstructionNew Construction

or Reconstructionor ReconstructionӨӨ CConcrete overlaysoncrete overlaysӨӨ Concrete roundabouts and intersectionsConcrete roundabouts and intersections

►► Specifications and materials for concrete pavementsSpecifications and materials for concrete pavements►► Construction inspection and testingConstruction inspection and testing



ConcreteConcrete’’s Sustainabilitys Sustainability

►► Improvements in Manufacturing ProcessImprovements in Manufacturing Process

Cement manufacturing accounts for about 1.5% of Cement manufacturing accounts for about 1.5% of manmade COmanmade CO22 and itand it’’s getting better with a reduction of s getting better with a reduction of 35% of CO35% of CO22 production since 1975.production since 1975.

►► Recycling Key Focus to Improve Manufacturing Recycling Key Focus to Improve Manufacturing ProcessProcess

The industry utilizes more than 20 million tons of coal The industry utilizes more than 20 million tons of coal combustion bycombustion by--products like flyproducts like fly--ash and bottom ash ash and bottom ash

In 2006, the Construction Materials Recycling Association In 2006, the Construction Materials Recycling Association estimated that approximately 125 to 140 million tons of estimated that approximately 125 to 140 million tons of concrete are recycled annuallyconcrete are recycled annually



ConcreteConcrete’’s Sustainabilitys Sustainability

►► Durability Means Longer Lasting, More Efficient Durability Means Longer Lasting, More Efficient StructuresStructures

►► Concrete Reflectivity Means Energy SavingsConcrete Reflectivity Means Energy Savings

Minimizes the effects that produce urban heat islands. Minimizes the effects that produce urban heat islands.

Light colored pavements also require less site lighting to Light colored pavements also require less site lighting to provide safe nightprovide safe night--time illumination levels, whether on time illumination levels, whether on parking lots, driveways, or sidewalks.parking lots, driveways, or sidewalks.

Concrete costs less in the Concrete costs less in the long runlong run

►► Federally funded studies show that concrete Interstate pavementsFederally funded studies show that concrete Interstate pavementscost 13cost 13--28% less in the long run than asphalt Interstate pavements.28% less in the long run than asphalt Interstate pavements.

►► Recent University of Minnesota studies in Olmsted and Waseca Recent University of Minnesota studies in Olmsted and Waseca counties show that the use of concrete pavement saved up to 19% counties show that the use of concrete pavement saved up to 19% in the long run over the cost of using and maintaining similar ain the long run over the cost of using and maintaining similar asphalt sphalt roads. roads.

►► The same studies shows that maintenance costs were reduced 75% The same studies shows that maintenance costs were reduced 75% when concrete was used to pave roads in these counties.when concrete was used to pave roads in these counties.

►► Advancements in concrete technology have reduced the cost of Advancements in concrete technology have reduced the cost of concrete paving while improving performance greatlyconcrete paving while improving performance greatly



Recent Trends in MichiganRecent Trends in Michigan

20%For 2008

12%



Concrete for CountiesConcrete for Counties

►►New Construction or ReconstructionNew Construction or Reconstruction

►►Concrete OverlaysConcrete Overlays

►►Concrete Intersections and RoundaboutsConcrete Intersections and Roundabouts

Concrete Pavement Types for Concrete Pavement Types for CountiesCounties

►►Jointed PlainJointed PlainUndoweledUndoweledDoweledDoweled

►►Jointed ReinforcedJointed Reinforced



Jointed PlainJointed Plain

10 – 20 ft

Plan

Profile

or

Jointed ReinforcedJointed ReinforcedPlan

Profile

25 – 100 ft



Concrete PavementsConcrete PavementsThickness DesignThickness Design

►► AASHTO Design MethodAASHTO Design Method

WinPAS softwareWinPAS software

►► ACPA StreetPave softwareACPA StreetPave software

►► Typical Thicknesses:Typical Thicknesses:

Major/Minor Arterials: 8Major/Minor Arterials: 8”” to 10to 10””

Collectors: 7Collectors: 7”” to 9to 9””

Residential: 5Residential: 5”” to 7to 7””

►► Many consultants and engineers are knowledgeable in concrete desMany consultants and engineers are knowledgeable in concrete design ign in your area. Also, contact Michigan Concrete Paving Associatioin your area. Also, contact Michigan Concrete Paving Association for n for assistance with your projectassistance with your project

Family of Concrete OverlaysFamily of Concrete Overlays

Bonded Concrete Overlay

Unbonded Concrete Overlay

Existing PavementConcrete

Conventional Whitetopping

Overlay

Ultra-Thin Whitetopping

Overlay

ConcreteOverlays

Existing Pavement

Asphalt



Unbonded Concrete OverlayUnbonded Concrete Overlay

........

........

....

....

....

..

..

..

►► Consists of thick concrete layer (5Consists of thick concrete layer (5”” or greater) or greater) on top of an existing concrete pavement.on top of an existing concrete pavement.

►► Uses a Uses a ““separation interlayerseparation interlayer”” to separate new to separate new overlay and existing concrete.overlay and existing concrete.

UnbondedUnbonded OverlayOverlay



When to Use When to Use UnbondedUnbonded OverlaysOverlays

►►Little or no remaining structural lifeLittle or no remaining structural life►►Extensive and severe durability Extensive and severe durability

distressdistress►►Medium to very heavy truck trafficMedium to very heavy truck traffic►►Very weak or wet Very weak or wet subgradesubgrade►►Other obstacles to reconstructionOther obstacles to reconstruction

Benefits

UnbondedUnbonded OverlayOverlay

►► Little preLittle pre--overlay repair neededoverlay repair needed►► Improved Structural Capacity.Improved Structural Capacity.

Very Strong Base that can maintain trafficVery Strong Base that can maintain trafficReduced Faulting, Pumping, & Loss of SupportReduced Faulting, Pumping, & Loss of Support

►► Can place on pavement in bad condition.Can place on pavement in bad condition.i.e. "D" cracked pavements, ASR, etc.i.e. "D" cracked pavements, ASR, etc.No future reflective cracking.No future reflective cracking.

►► Avoids reconstruction problemsAvoids reconstruction problemsLess construction timeLess construction time



UnbondedUnbonded OverlayOverlayPrePre--overlay Repairoverlay Repair

UnbondedUnbonded overlays are less sensitive to underlying overlays are less sensitive to underlying pavement condition than any other overlay typepavement condition than any other overlay type

May be needed:May be needed:Repair/replace shattered or rocking slabsRepair/replace shattered or rocking slabsRepair Repair punchoutspunchouts in CRCPin CRCP

Probably not needed:Probably not needed:Repair of other slab crackingRepair of other slab cracking

Repair of joint Repair of joint spallingspallingLoad transfer restoration Load transfer restoration

UnbondedUnbonded Concrete OverlayConcrete Overlay

►► Allows layers to act independently.Allows layers to act independently.

►► Prevents distresses from reflecting into Prevents distresses from reflecting into overlay. overlay.

►► Materials that work:Materials that work:Asphalt concreteAsphalt concreteSome surface treatments Some surface treatments

►► Existing AC overlayExisting AC overlaycan be used as interlayercan be used as interlayerbut may need to be milledbut may need to be milledif excessively rutted, etc.if excessively rutted, etc.

Separation Interlayer:



JointingUnbondedUnbonded OverlaysOverlays

►►Mismatch joints.Mismatch joints.►►Saw joints d/3.Saw joints d/3.

3 FT.3 FT.

Overlay joints should bemismatched from working cracks too

UnbondedUnbonded Concrete OverlayConcrete Overlay

►►Very GoodVery Good►►Can be expected to perform for 20+ Can be expected to perform for 20+

years. years. Most failures are due to the use of Most failures are due to the use of inadequate separation layers.inadequate separation layers.

Performance



Concrete Overlays in MichiganConcrete Overlays in Michigan

►► WhitetoppingWhitetopping (concrete on asphalt)(concrete on asphalt)►►Thin Thin UnbondedUnbonded Concrete OverlaysConcrete Overlays

Good choice for many city/county roads & Good choice for many city/county roads & streetsstreets

Existing concrete or composite pavementExisting concrete or composite pavement

Concrete Concrete WhitetoppingWhitetopping

MillMill and and FillFill with Concretewith Concrete




►► Consists of thin concrete layer (Consists of thin concrete layer (typtyp. 4 in. or less) on . 4 in. or less) on top of an existing asphalt pavement. top of an existing asphalt pavement.

►► Specific steps are taken to Specific steps are taken to bondbond the new concrete to the new concrete to the existing asphalt and to the existing asphalt and to saw short joint spacingsaw short joint spacing..

May or may not contain fibersMay or may not contain fibers

........

........

....

..

..


►► Designed to be a cost competitive midDesigned to be a cost competitive mid--term fixterm fix

Actual initial cost bid pricesActual initial cost bid pricesHas been shown to last longer than alternative Has been shown to last longer than alternative paving materialspaving materials

►► Designed for minimal impact on Designed for minimal impact on traveling publictraveling public

No earthwork requiredNo earthwork requiredWeekend closuresWeekend closures



Thin Concrete Overlays of Composite Thin Concrete Overlays of Composite Pavements or Existing Concrete Pavements or Existing Concrete

PavementsPavements

New Concrete Overlay

Asphalt Separator Layer

Old Concrete Pavement

Concrete OverlaysConcrete Overlays

►►Not hard to constructNot hard to construct►►Do not require extensive engineering Do not require extensive engineering

expense expense –– more field engineering than more field engineering than plans & surveyplans & survey

►►Initial cost is competitive with other Initial cost is competitive with other rehab optionsrehab options

►►Can be constructed quickly with Can be constructed quickly with minimal traffic impactminimal traffic impact



M-3 (Gratiot Ave.), Detroit

Scoping/Design IssuesScoping/Design Issuesfor for WhitetoppingWhitetopping and Thin and Thin UnbondedUnbonded


►►PrePre--Design InvestigationDesign InvestigationVisual examination of pavementVisual examination of pavement►►Check the profile grade lineCheck the profile grade line►►Repairs not typical, only needed for areas of Repairs not typical, only needed for areas of

extremely poor support, extremely poor support, subgradesubgrade failurefailure

CoresCores►►The more, the betterThe more, the better




Concrete OverlaysConcrete Overlays►►MillingMilling

Reduces need for adj. structures, tieReduces need for adj. structures, tie--ins to ins to driveways, overhead clearances, etc.driveways, overhead clearances, etc.Roughened surface enhances bondRoughened surface enhances bond

►►SupportSupportAdequate asphalt thickness after milling?Adequate asphalt thickness after milling?►►Minimum 3 inches desiredMinimum 3 inches desired

Thicken up Thicken up whitetoppingwhitetopping in areas of weak in areas of weak support (over culverts, support (over culverts, subgradesubgrade failures)failures)



►►ThicknessThickness4 inches typical in Michigan4 inches typical in Michigan3.5 inches common (2x4 forms)3.5 inches common (2x4 forms)

►►Design LifeDesign LifeCan be estimated/predicted with softwareCan be estimated/predicted with software10 to 15 years is target10 to 15 years is targetProperly designed & constructed, can be >20 Properly designed & constructed, can be >20 yearsyears



Construction StepsConstruction Steps

►►Mill and clean the asphaltMill and clean the asphalt►►Place, finish, and cure the concretePlace, finish, and cure the concrete►►EarlyEarly--entry saws for control jointsentry saws for control joints►►Open to trafficOpen to traffic

1500 to 3000 1500 to 3000 psipsi compressive, orcompressive, or350 to 550 350 to 550 psipsi flexuralflexural►►Actual number depends on amount of heavy Actual number depends on amount of heavy

commercial trafficcommercial traffic

Traverse City, Traverse City, CornillieCornillie Concrete Concrete 3.5" UTW, 19963.5" UTW, 1996



CornillieCornillie Concrete, 2004Concrete, 2004

CornillieCornillie Concrete, 2004Concrete, 2004



CornillieCornillie Concrete, 5/2/07Concrete, 5/2/07

Why Concrete for Intersections?Why Concrete for Intersections?

►►Use where asphalt has not performedUse where asphalt has not performed



Construction of Concrete Construction of Concrete IntersectionsIntersections

Construction: MOT OptionsConstruction: MOT Options

Complete Closure with Detours

ROAD CLOSEDUSE DETOUR

• Clear and understandable signing • Sign indicating when reopens




Partial Closure with Detours

• Only one-leg closed• Allow traffic on major roadway

ROAD CLOSEDUSE DETOUR


Complete Closure During Time-Window

• Typically 7 p.m. to 6 a.m. window• Night construction in sequences• May require temporary pavement

CLOSEDREOPENS 6 A.M.




Construction Under Traffic - by Lane

Phase 1 Phase 2 Phase 3 Phase 4


Construction Under Traffic - by Quadrant

Phase 1 Phase 2 Phase 3 Phase 4



ExampleExample

Stage 1Stage 1



Stage 2Stage 2

Stage 3Stage 3



Construction Under ClosureConstruction Under Closure

Concrete Roundabouts for Local Concrete Roundabouts for Local AgenciesAgencies

►► Alternative to traffic Alternative to traffic signal and cost signal and cost associated with associated with installation and installation and maintenancemaintenance

►► Concrete handles Concrete handles turning movements turning movements better than asphaltbetter than asphalt



2-LanePinwheel

Concrete RoundaboutConcrete RoundaboutOpened to TrafficOpened to Traffic



Concrete Specifications and MaterialsConcrete Specifications and Materials

Durability by Design and Materials

Concrete Mix DesignConcrete Mix Design

►►Key requirements:Key requirements:DurabilityDurabilityRight strength at the right timeRight strength at the right timeWorkability / Workability / PlaceabilityPlaceabilityCost effectivenessCost effectiveness



Concrete DurabilityConcrete Durability

►►Need to ensure:Need to ensure:Proper air content (more is better!!)Proper air content (more is better!!)Proper mixingProper mixingNo addition of waterNo addition of water►►To the mixer at the siteTo the mixer at the site►►To the surface of the slabTo the surface of the slab

Proper & timely curingProper & timely curing

Concrete StrengthConcrete Strength

►► Pavements donPavements don’’t fail t fail due to due to lowlow strength strength –– they fail due to they fail due to durabilitydurability problemsproblems

►► Need to focus less Need to focus less on strength, more on on strength, more on producing durable producing durable concreteconcrete



What are we looking for in a What are we looking for in a concrete specification? concrete specification?

►► Well defined and achievable requirements.Well defined and achievable requirements.

What concrete specifications are What concrete specifications are currently available to us? currently available to us?

►► MDOT specifications, 2003 Spec BookMDOT specifications, 2003 Spec BookDivision 3 Division 3 -- BasesBasesDivision 6 Division 6 –– Portland Cement Concrete PavementsPortland Cement Concrete Pavements

Section 601 PCC Pavement MixturesSection 601 PCC Pavement MixturesSection 602 Concrete Pavement ConstructionSection 602 Concrete Pavement ConstructionSection 603 Concrete Pavement RestorationSection 603 Concrete Pavement RestorationSection 604 Contractor Quality Control for ConcreteSection 604 Contractor Quality Control for ConcreteSection 605 Concrete Quality AssuranceSection 605 Concrete Quality Assurance

Division 7 Division 7 –– StructuresStructuresSection 701 Portland Cement Concrete for StructuresSection 701 Portland Cement Concrete for Structures

Division 8 Division 8 –– Incidental ConstructionIncidental ConstructionSection 801 Concrete DrivewaysSection 801 Concrete DrivewaysSection 802 Concrete Curb, Gutter and DividersSection 802 Concrete Curb, Gutter and DividersSection 803 Concrete Sidewalk, Ramps and StepsSection 803 Concrete Sidewalk, Ramps and Steps

Division 9 Division 9 –– MaterialsMaterialsSection 901 Cement and LimeSection 901 Cement and LimeSection 902 AggregatesSection 902 AggregatesSection 903 Admixtures and Curing MaterialsSection 903 Admixtures and Curing Materials



What concrete specifications are What concrete specifications are currently available to us? currently available to us?

►► MDOT P1 Modified (High Performance MDOT P1 Modified (High Performance Concrete) Special Provision Concrete) Special Provision

►► Industry recommended or developed Industry recommended or developed specifications and special provisions.specifications and special provisions.

MCPA Durability Spec for Local Agencies (2006)MCPA Durability Spec for Local Agencies (2006)MCPA Cold Weather Guide Spec (2007)MCPA Cold Weather Guide Spec (2007)MCPA Local Ride Quality SpecMCPA Local Ride Quality SpecMCPA Concrete MCPA Concrete WhitetoppingWhitetopping SpecSpecACPA, PCA Guide SpecificationsACPA, PCA Guide Specifications

P1 Modified (High Performance P1 Modified (High Performance Concrete Pavement)Concrete Pavement)

►►Improved Workability Improved Workability –– finishers love itfinishers love it►►Increased Strength with Less Cement Increased Strength with Less Cement ––

better durability; lower costbetter durability; lower cost►►Decreased Permeability Decreased Permeability –– less moisture less moisture

in pavementin pavement►►Helps Admixture Effectiveness Helps Admixture Effectiveness –– better better

airair►►Assures Consistency of Mix Assures Consistency of Mix –– lower lower

segregation potentialsegregation potential



Sample Mix Design SubmittalSample Mix Design SubmittalCONCRETE MIX DESIGNCONCRETE MIX DESIGN

Project:Project: Broadway Ave. ReconstructionBroadway Ave. Reconstruction

Contractor:Contractor: Concrete Paving LLCConcrete Paving LLC

Mix Type:Mix Type: Mainline Mainline SlipformSlipform PavingPaving

Design Strength:Design Strength: 3500 3500 psipsi @ 28 days@ 28 days

Air Content:Air Content: 6.5% 6.5% ±± 1.5%1.5%

Mix Design ID:Mix Design ID: P1Mod#1P1Mod#1

MaterialMaterial TypeType SourceSource Sp. Gr.Sp. Gr. SSD Wt. (lb)SSD Wt. (lb) Yield (ftYield (ft33))

CementCement ASTM C 150 Type IASTM C 150 Type I EssrocEssroc 3.153.15 368368 1.871.87

Fly AshFly Ash ASTM C 618 Class FASTM C 618 Class F ReliantReliant 2.552.55 00 0.000.00

SlagSlag ASTM C 989 Gr. 120ASTM C 989 Gr. 120 LafargeLafarge 2.892.89 158158 0.880.88

Fine Fine AggAgg.. MDOT 2NSMDOT 2NS Pit 75Pit 75‐‐55 2.672.67 14001400 8.408.40

IntermedIntermed. . AggAgg.. MDOT 26AMDOT 26A Pit 75Pit 75‐‐55 2.672.67 762762 4.574.57

Coarse Coarse AggAgg.. MDOT 6AAMDOT 6AA Pit 41Pit 41‐‐152152 2.662.66 970970 5.845.84

WaterWater PotablePotable MunicipalMunicipal 1.001.00 238238 3.813.81

FibersFibers FibermeshFibermesh PropexPropex 0.910.91 1.51.5 0.030.03

Air Entrain.Air Entrain. ASTM C 260ASTM C 260 AximAxim 1.751.75

38983898 27.1627.16

AdmixturesAdmixtures

Air EntrainmentAir Entrainment 1.41.4 oz./cwt.oz./cwt. AximAxim AE260AE260

Water ReducerWater Reducer ASTM C 494 Type AASTM C 494 Type A BASF BASF MasterBuildersMasterBuilders PolyheedPolyheed 900900

4.04.0 oz./cwt.oz./cwt. 2" slump 2" slump ±± 1"; 1"; slipformslipform

8.08.0 oz./cwt.oz./cwt. 5" slump 5" slump ±± 1"; handwork1"; handwork

w/cm ratiow/cm ratio 0.450.45

Proportion

Mix Design SubmittalsMix Design Submittals

Should also contain:Should also contain:►►Strength resultsStrength results

OverdesignOverdesign for chance of low strength for chance of low strength test results means that their strengths test results means that their strengths may need to be significantly higher than may need to be significantly higher than the design.the design.



First Items to Check in a Mix First Items to Check in a Mix Design SubmittalDesign Submittal

MDOT Qualified Products List in the MDOT Qualified Products List in the Materials Source GuideMaterials Source Guide

Aggregate pit numbersAggregate pit numbers

Cement, slag, and fly ash manufacturers / Cement, slag, and fly ash manufacturers / sourcessources

Cement content; total Cement content; total cementitiouscementitious contentcontentWater / Water / cementitiouscementitious ratioratioIf yield numbers given, check air contentIf yield numbers given, check air contentAny other spec requirementsAny other spec requirements

Mix Design Approval ChecklistMix Design Approval ChecklistConcrete Mix Design Approval Checklist

Cementitious materials:

From facility or manufacturer on MDOT Approved Manufacturers List? www.michigan.gov/mdot/

click “doing business” (on left) click “Construction and Technology” click “Manuals & Guides” (down the page) click “Materials Source Guide”

Cementitious materials content minimized (≤ 564 lb/cyd i.e. ≤ 6‐sack; max. of 658 lb/cyd i.e. ≤ 7‐sack)?

Fly ash content ≤ 25% of total cementitious content?

Slag cement (GGBFS) content ≤ 40% of total cementitious content?

Total SCM (slag + fly ash) content ≤ 50% of total cementitious content?

w/cm ratio ≤ 0.50 for fixed form or hand pours; w/cm ratio ≤ 0.45 for slipform? Aggregates:

From certified pits? (see Approved Manufacturers in Materials Source Guide)

Combined, the coarse and fine aggregates make up 60% to 75% of the total concrete volume?

Proportion (by weight) of coarse‐to‐fine aggregate is around 60/40; roughly 55% to 65% coarse, and 35% to 45% fine?

Combined aggregate gradation analyzed; mix design in a good zone on workability chart?

Fineness modulus of fine aggregate (sand) analyzed and in higher range (2.7 and above, 3.0 to 3.5 or higher works best)?

Other:

Admixtures from Qualified Products List? (see Materials Source Guide)

Admixture dosage within limits? (check QPL for specifics) o Air entrainment usually around 1.0 to 3.0 oz/cwt to achieve 5‐8% o Type A water reducer usually up to 4.0 oz/cwt o Mid‐range water reducer usually up to 8.0 oz/cwt o High‐range (superplasticizer) not usually recommended except for pumping or very low

w/cm ratio

Air content checked against yield calcs?

Fibers in the mix? o Synthetic fiber dosage rate usually 1.5 lb/cyd (1 bag per cyd)



Key Points to Examine in a Mix Key Points to Examine in a Mix Design SubmittalDesign Submittal

Cement content Cement content –– keep as low as possiblekeep as low as possibleWater / cement ratio Water / cement ratio –– keep as low as keep as low as possiblepossibleCoarse / fine Coarse / fine aggagg. ratio . ratio –– 55/45 to 65/3555/45 to 65/35Use wellUse well--graded aggregates graded aggregates –– look at look at combined gradationcombined gradationSlump Slump ≠≠ quality; Slump = workability; quality; Slump = workability; ∆∆ slump = variabilityslump = variabilityFreezeFreeze--thaw durability = good air systemthaw durability = good air system

AggregatesAggregates

►► 60% to 75% of the concrete60% to 75% of the concrete’’s volumes volume►► Proportion (by weight) of coarseProportion (by weight) of coarse--toto--fine aggregate fine aggregate

is typically around 60/40is typically around 60/40Usually ranges from 55/45 to 65/35Usually ranges from 55/45 to 65/35

►► Properties affecting concrete:Properties affecting concrete:ShapeShapeFreezeFreeze--thaw durabilitythaw durabilityLA Abrasion, soft particles, LA Abrasion, soft particles, chertchert, alkali silica reactivity, alkali silica reactivityGradationGradation



Rounded AggregatesRounded Aggregates

Cubical AggregatesCubical Aggregates



Flat, Elongated, and Angular Flat, Elongated, and Angular AggregatesAggregates

Intermediate AggregatesIntermediate Aggregates

PEA GRAVELPEA GRAVELLIMESTONE CHIPSLIMESTONE CHIPS

SLAG AGGREGATESLAG AGGREGATE



GradationGradation

GradationGradation

►► Gap Graded MixesGap Graded Mixessegregate more easilysegregate more easilydifficult to placedifficult to placehigher amount of higher amount of finesfinesrequire more cementrequire more cementgreater water greater water demanddemand



GradationGradation

►► Well Graded MixesWell Graded Mixesless prone to less prone to segregationsegregationeasier to placeeasier to placelower amount of lower amount of finesfinesrequire less cementrequire less cementless water demandless water demand

Individual Gradations Individual Gradations -- Range Range

MDOT 6AA MDOT 6AA (Coarse (Coarse AggAgg.).)Sieve % PassingSieve % Passing

1.5 in.1.5 in. 100100

1.0 in.1.0 in. 9595--100100

½½ in.in. 3030--6060

No. 4No. 4 00--88

No. 200 (LBW)No. 200 (LBW) 1.0 max1.0 max

MDOT 2NS MDOT 2NS (Fine (Fine AggAgg.).)Sieve % PassingSieve % Passing

⅜⅜ in.in. 100100

No. 4No. 4 9595--100100

No. 8No. 8 6565--9595

No. 16No. 16 3535--7575

No. 30No. 30 2020--5555

No. 50No. 50 1010--3030

No. 100No. 100 00--1010

No. 200 (LBW)No. 200 (LBW) 00--33



Individual Gradations Individual Gradations -- RangeRange

MDOT 26A MDOT 26A ((IntermedIntermed. . AggAgg.).)Sieve % PassingSieve % Passing

¾¾ in.in. 100100

½½ in.in. 9595--100100

⅜⅜ in.in. 6060--9090

No. 4No. 4 55--3030

No. 8No. 8 00--1212

No. 200 (LBW)No. 200 (LBW) 3.0 max3.0 max

Combined GradationCombined Gradation

6AA6AA 26A26A 2NS2NS CombinedCombined PercentPercent% Blend % Blend 36%36% 22%22% 0%0% 42%42% 100%100% RetainedRetainedSieve SizeSieve Size Percent PassingPercent Passing

22 100.0100.0 100.0100.0 100.0100.0 100.0100.0 100.0100.0 0.00.01 1/21 1/2 100.0100.0 100.0100.0 100.0100.0 100.0100.0 100.0100.0 0.00.0

11 96.096.0 100.0100.0 100.0100.0 100.0100.0 98.698.6 1.41.43/43/4 69.069.0 100.0100.0 100.0100.0 100.0100.0 88.888.8 9.79.71/21/2 40.040.0 98.098.0 100.0100.0 100.0100.0 78.078.0 10.910.93/83/8 4.04.0 79.079.0 100.0100.0 100.0100.0 60.860.8 17.117.1#4#4 1.01.0 25.025.0 96.096.0 97.097.0 46.646.6 14.214.2#8#8 0.00.0 8.08.0 85.085.0 85.085.0 37.537.5 9.19.1

#16#16 0.00.0 1.01.0 70.070.0 60.060.0 25.425.4 12.012.0#30#30 0.00.0 0.00.0 40.040.0 40.040.0 16.816.8 8.68.6#50#50 0.00.0 0.00.0 12.012.0 15.015.0 6.36.3 10.510.5

#100#100 0.00.0 0.00.0 3.03.0 3.03.0 1.31.3 5.05.0#200#200 0.00.0 1.01.0 1.01.0 2.02.0 1.11.1 0.20.2

Excel spreadsheet



Combined Gradation Combined Gradation –– PlotPlot

Coarseness & Workability Factors Coarseness & Workability Factors **

* per James M. Shilstone, Sr., ”Concrete Mixture Optimization,”Concrete International, June 1990

CF = Coarseness FactorWF = Workability Factor



Workability ChartWorkability Chart

0.45 Power Chart0.45 Power Chart



Fibers Fibers

Synthetic FibersSynthetic Fibers

►►Reduce shrinkage Reduce shrinkage ►►Improve impact and shatter resistanceImprove impact and shatter resistance►►Better abrasion resistanceBetter abrasion resistance►►More concrete toughness (postMore concrete toughness (post--crack crack

integrity)integrity)►►Typical dosage rate: 1.5 lb/Typical dosage rate: 1.5 lb/cydcyd



Inspection & TestingInspection & TestingKeys to a Good Concrete ProjectKeys to a Good Concrete Project

►► Open communication; good organizationOpen communication; good organization►► Consistent supply of materials = good project flowConsistent supply of materials = good project flow►► Construction is a material handling business!Construction is a material handling business!

Contractor Quality Control Contractor Quality Control Testing PlanTesting Plan

►►Sampling and Testing (at a minimum)Sampling and Testing (at a minimum)Concrete Slump, Temperature, and AirConcrete Slump, Temperature, and Air►►On the first load and on subsequent loads if On the first load and on subsequent loads if

directed by Engineer for each grade of concrete directed by Engineer for each grade of concrete delivered each day.delivered each day.

►►During placement at minimum of once per hourDuring placement at minimum of once per hour►►Quality Control tests may coincide with the Quality Control tests may coincide with the

tests required for acceptance cylinders.tests required for acceptance cylinders.

Concrete StrengthConcrete Strength►►Determine strength on samples taken at Determine strength on samples taken at

least once every 200 yards.least once every 200 yards.



Bases Bases

►► Section 301 Section 301 SubbaseSubbase (p. 163)(p. 163)301.01 Construction301.01 Construction►►Construct the Construct the subbasesubbase to plan grade within a tolerance of to plan grade within a tolerance of

plus one inch. plus one inch. ►►Do not place Do not place subbasesubbase on frozen, soft or unstable or rutted on frozen, soft or unstable or rutted

subgradesubgrade..

►► Section 302 Aggregate Base Courses (p. 164)Section 302 Aggregate Base Courses (p. 164)302.03. A. Placing and compacting302.03. A. Placing and compacting►►Tickets for each load verifying source and other Tickets for each load verifying source and other

informationinformation►►Uniform gradation with no contaminationUniform gradation with no contamination►►Compaction requirementsCompaction requirements

Mixing ConcreteMixing Concrete




►►Table 601Table 601--1, Time Between Charging 1, Time Between Charging Mixer and Placing ConcreteMixer and Placing Concrete

Type of UnitType of UnitConcrete Temperature (ASTM C Concrete Temperature (ASTM C

1064)1064)<60<60°°FF 60 to 8560 to 85°°FF >85>85°°FF

Open Top TrucksOpen Top Trucks 6060 6060 3030

Open Top Agitating UnitsOpen Top Agitating Units 6060 4545 3030

Closed Top Agitating Units and Closed Top Agitating Units and Truck MixersTruck Mixers 9090 6060 4545

Truck Mixers and Closed Top Truck Mixers and Closed Top Agitating Units with WaterAgitating Units with Water--Reducing Retarding AdmixtureReducing Retarding Admixture

120120 9090 7070

All times shown are in minutes.All times shown are in minutes.


►►Addition of Water at Placement SiteAddition of Water at Placement SiteDo not add more water than the approved Do not add more water than the approved mix design will allow based on maximum mix design will allow based on maximum water content and max water content and max w/cw/c material ratio.material ratio.Document all water being addedDocument all water being addedAllow minimum 30 revs of truck mixer at Allow minimum 30 revs of truck mixer at mixing speed before dischargemixing speed before discharge



Concrete TestingConcrete Testing►►Temperature, Slump, Temperature, Slump,

Yield, Air Content Yield, Air Content ►►Concrete must be Concrete must be

between 45 and 90 between 45 and 90 degrees F at the time it degrees F at the time it is placed.is placed.

►Slump – not to exceed 3 inches typically

►Yield within limits -0% to +2%

Air ContentAir Content

►► Pressure meter or rollPressure meter or roll--aa--metermeter

►► 5% to 8% (6.5% 5% to 8% (6.5% ±±1.5%)1.5%)

Stay on high sideStay on high side

SpotSpot--check the incheck the in--place place air content behind air content behind concrete placementconcrete placement



Inspection also Inspection also needed for:needed for:

Placing FormsPlacing Forms

Placing ConcretePlacing Concrete

TexturingTexturing

CuringCuring

VibrationVibration



DonDon’’t bless the slabt bless the slab

DonDon’’t be cheap with the curing t be cheap with the curing compoundcompound



Key PointsKey Pointsfor Good Durabilityfor Good Durability

►►Start with good, durable materialsStart with good, durable materials►►Air = freezeAir = freeze--thaw durabilitythaw durability►►Mix it properlyMix it properly►►Minimize cement content; use Minimize cement content; use SCMSCM’’ss at at

appropriate amounts & timesappropriate amounts & times►►Minimize waterMinimize water►►Cure!!!Cure!!!

SummarySummary

►► Design Design –– keep it simplekeep it simple►► Specs Specs –– use MDOT specs, special provisions use MDOT specs, special provisions

where neededwhere needed►► Mix Design Mix Design –– look at gradationslook at gradations►► Inspection Inspection –– open communication, open communication,

teamwork is key; keep an eye on air contentteamwork is key; keep an eye on air content►► Durability Durability –– good air system and good good air system and good

curing are critical; finishing techniques, curing are critical; finishing techniques, minimizing use of water also keyminimizing use of water also key



ItIt’’s all in the design!!s all in the design!!

Alpena Community College and the Alpena Community College and the World Center for Concrete World Center for Concrete

TechnologyTechnology



WORLD CENTER FOR WORLD CENTER FOR CONCRETE CONCRETE

TECHNOLOGYTECHNOLOGY

ALPENA COMMUNITY COLLEGEALPENA COMMUNITY COLLEGEALPENA, MICHIGANALPENA, MICHIGAN

www.wcct.netwww.wcct.net989989--358358--72387238

What is the WCCT?What is the WCCT?►► Over 43,000 square feet of training facility Over 43,000 square feet of training facility

dedicated to the education and training of dedicated to the education and training of concrete industry personnel concrete industry personnel

►► Fully automated, computer controlled concrete Fully automated, computer controlled concrete masonry production facilitymasonry production facility

►► Testing laboratories using stateTesting laboratories using state--ofof--thethe--art art equipment for soils, aggregates, and concreteequipment for soils, aggregates, and concrete

►► Modern classrooms with full computer access for Modern classrooms with full computer access for delivering classes around the worlddelivering classes around the world

►► Opened in 2000, 10 year anniversary activities Opened in 2000, 10 year anniversary activities planned for 2010!!!!planned for 2010!!!!



ACCACC’’s A.A.S. Degree in s A.A.S. Degree in Concrete TechnologyConcrete Technology

Started in late 1960Started in late 1960’’s as one of original s as one of original associateassociate’’s degree programs by Portland s degree programs by Portland Cement AssociationCement Association


►►22--year degree program covering:year degree program covering:

►►Construction Inspection and TestingConstruction Inspection and Testing►►AggregatesAggregates►►CementitiousCementitious materialsmaterials►►Concrete MasonryConcrete Masonry►►ReadyReady--mixed Concretemixed Concrete►►AdmixturesAdmixtures►►PrecastPrecast and and PrestressedPrestressed




Job Opportunities:Job Opportunities:►►ManagementManagement►►Quality ControlQuality Control►►InspectionInspection►►SalesSales►►Research & DevelopmentResearch & Development►►Technical ServiceTechnical Service►►Production/SupervisionProduction/Supervision►►EngineeringEngineering

DEVELOPING A DEVELOPING A SKILLED SKILLED

WORKFORCEWORKFORCE



What is happening now at ACC What is happening now at ACC and the WCCT?and the WCCT?

►►Online coursesOnline courses►►CementitiousCementitious MaterialsMaterials►►Concrete Masonry TechnologyConcrete Masonry Technology►►Admixtures for ConcreteAdmixtures for Concrete►►Optimizing Concrete MixesOptimizing Concrete Mixes►►Aggregates Aggregates ►►Basic Concrete Mix ProportioningBasic Concrete Mix Proportioning►►Introduction to Concrete TechnologyIntroduction to Concrete Technology►►And many more upcoming!!!And many more upcoming!!!

We have qualified students now We have qualified students now for summer internships and fullfor summer internships and full--

time employmenttime employment

For more information on the For more information on the program and hiring interns or program and hiring interns or graduates, see me or email to graduates, see me or email to

[email protected]@alpenacc.edu!!!!!!



Questions / Discussion?Questions / Discussion?

Thank you for your time.Thank you for your time.

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