GeotechnicalLightweightFillCompetitionOverviewLightweightgeotechnicalfillhasbeenusedinplaceofsoilforbuildingroadwayembankments,retainingwalls,andasbackfillaboveburiedpipelinesasamoreeconomicallyviableandlightweightmaterial.Expandedpolystyrene,alsocalledgeofoam,istypicallyusedintheseapplications.Apartfrommanyadvantages,usinggeofoamhasdrawbacksincluding:adverseenvironmentalimpact,incompatibilitywithpetroleumproducts,flammability,etc.Researchregardingrecycledlightweightfillhasbeenconductedtoinvestigatetheopportunitytoreplacegeofoamwithamoresustainableandeconomicallyviablematerial.Divertingpotentiallyrecyclablematerialfromlandfillsandrepurposingitforuseincivilengineeringapplicationsoffersmanyenvironmentalbenefits,aswellassavingmanufacturingandprocessingcosts.Forexample,oneprojectusedPETbottlesassubgradeforbiketrails,buttheproofofconcepthasnotyetbeenexpandedtoroadwayprojects(Graettinger,2005).ObjectiveTheobjectiveoftheGeotechnicalLightweightFillCompetitionistocreateanewsustainablelightweightfillandexplorethemechanicalproperties,sustainability,andconstructabilityofthisnewmaterialasalightweightgeotechnicalfill.Theparticipantswillcreateanewrecycledlightweightfillmaterial,characterizethematerial,andtestthematerialstrengththroughanunconfinedcompressiontest.EligibilityEachteammayconsistofamaximumoffour(4)members,one(1)ofwhichmaybeagraduatestudent.MaterialsMaterialsrequiredforthiscompetitionare:

• Calculator• Pen/Pencil• Recycledmaterialusedinlightweightfill• Bindingagent

ExecutionConstructionGuidelinesEachteamwillconstructone2ft.x2ft.x2ft.cubefromrecycledmaterialpriortothecompetition.Teamsmustuseeasilyaccessiblerecyclablematerialthatcanbeheldtogetherwithabindingagent.Eachmaterialusedmustbelistedonthematerialbreakdownformandjustifiedassustainable,recyclable,andconstructibleonthematerialpropertiesform.Therecannotbeanyliquidinthelightweightfillcubes.Figure1(a)showsanexampleoflightweightfillcubesthatwereconstructedfromemptyplasticbottlesusingvariousbindingagents.TestingProcedureEachteamwillbringitslightweightfillcubetothedesignatedtestingareaatthecompetition.Beforetesting,eachcubeoflightweightfillwillhavetofitcompletelyinsidea2ft.x2ft.x2ft.moldinallorientations.Cubesthatcannotfitthroughthemoldwillbedisqualified.Note:Allteammembersmustbewearinglongpantsandclosedtoedshoestobeadmittedintothetestinglab.

1. Totalweightofthecube:Eachteamwillrecordaweightforthelightweightfillcubeonthematerialpropertiesform.Totalweightmaynotexceed100pounds.

2. Unconfinedcompressiontest:Thecubeswillbesubjectedtoanunconfinedcompressiontest.Duetotimeconstraints,cubeswillbetestedtoamaximumstrainof15%andamaximumcompressiveloadof16,000pounds.Thecubeswillbecompressedataloadingrateof3%strainperminute.Cubesmustmeetaminimumloadof1,000poundsat15%strain.

3. Calculateweight/loadratio:Basedontheloadanddisplacementvaluesgeneratedthroughoutthecompressiontest,studentswillreceiveastressvs.straincurve,amaximumunconfinedcompressiveloadvalue,andaYoung’smodulusvaluegeneratedfromthetest.Thepeakstress(max4,000lb/ft2)andpeakstrain(max15%)valueswillbeusedtocalculatetheweight/loadratio.Themaximumunconfinedcompressivestrength,Young’smodulus,andweight/loadratiowillberecordedonthematerialpropertiesform.

4. Justification:Studentswilljustifythesustainabilityandconstructabilityofthelightweightcubebywritingajustificationstatementonthematerialpropertiesform.Teamsshouldconsidercostpercubicfoot,second-useapplications,regionalavailability,renewability,durability,andaddressanybarriersthatwouldpreventthewidespreaduseofthematerialasalightweightfill.Thestatementmaybehandwritteninthespaceprovidedonthematerialpropertiesformortypedpriortothecompetitionandbroughttothetesting

location.Thetypedstatementshouldbesingle-spaced,12pointfont,andamaximumofone(1)pagelong.

TheUniversityofAlabamawillsupplythetestingapparatus,showninFigure1(b),aswellastechnicianswhowillrunthetest.Onceeachteamsubmitsitscube,theywillnotbeabletomakechangestoit.

Figure1.(a)Examplelightweightfillcubes(b)CubeswillbetestedbyverticallyloadingthetopandbottomofthesampleusingaMTSAllianceRF/150testingmachine.

RequirementsTheconstructionandtestingrequirementsaresummarizedbelow.

• Cubemustfitinsidea2ft.x2ft.x2ft.moldinalldirectionspriortocompetition.

• Cubemustbemadeprimarilyofrecycledmaterial.(Itisatthejudges’discretionwhatconstitutesarecycledmaterial,majorityrules)

• Weightmaynotexceed100pounds.• Cubemaynotincludeanyliquid.

(a)

(b)

• Teamsmusttaketheircubewiththemafterithasbeenscored.Cubesmaynotbedisposedofoncampusorleftinthetestinglabaftertheconclusionofthecompetition.

Itemssubmittedtothejudgesduringthecompetition:• 2ft.x2ft.x2ft.lightweightfillcube• Materialpropertiesform• Justificationwrite-up(ifnothandwrittenonthematerialpropertiesform)• Materialbreakdownform

MaterialBreakdownFormThematerialbreakdownformshouldbecompletedpriortothecompetitionandsubmittedalongwiththeotheritemstothejudgesduringthecompetition.EachmaterialandbindingagentusedinconstructingthecubeshouldbelistedintheMaterialcolumn.Foreachmaterial,calculatethepercentofthetotalvolumeandthepercentofthetotalweightthatthematerialrepresentsinthesample.Estimatetheunitcostpercubicfootoflightweightfillandthesub-totalforeachmaterial.Apriceforanydonatedorfreematerialsshouldbeincludedinthecost.Sumthesub-totalvaluestocalculateatotalcostforthelightweightfillsample.Specifyagrainsizerangeinthespaceprovided.Forexample,ifPETbottlesareused,therangemaybefrom12ouncebottlestogallonjugs.Usingthetotalcostofthelightweightfillsample,estimatethecosttoconstructaroadwayembankmentrequiring100,000cubicyardsoflightweightfill.JudgingTherewillbeaminimumofthree(3)judgesforthecompetition.Itwillbethejudges’dutyandresponsibilitytoevaluatetheteamsfairlyandconsistently.TheteamswillbeevaluatedbasedonthecriteriaoutlinedintheScoringsectionincludedbelow.Thejudges’rulingwillbefinalforallcompetitors.ScoringTeamswillbescoredbasedontheunitweight,strength,constructability,andeconomyoftheirlightweightcube.Anytypeofrecycledmaterialcanbeusedinthecompetition,buttheteamwiththemostcreativematerialwillbeawardedabonusoffive(5)points.PleasereferencetheScoringSummarySheetforaspecificbreakdownofpoints.

DisqualificationsAnyteamthatdoesnotabidebytheregulationspresentedaboveorperformsunethicallywillbedisqualified.

ReferencesGraettinger,AndrewJ.,etal."Recyclingofplasticbottlesforuseasalightweightgeotechnicalmaterial."ManagementofEnvironmentalQuality:AnInternationalJournal16.6(2005):658-669.

MaterialPropertiesFormASCEStudentOrganization:_______________________________________TotalWeight(lb):UnitWeight(lb/ft3):MaxUnconfinedCompressiveLoad(lb):MaxUnconfinedCompressiveStrength(lb/ft2):Young’sModulus(lb/in2):Weight/LoadRatio(lb/lb):JustificationStatement:(responsescancontinueontothebackofthissheet)

MaterialBreakdownFormASCEStudentOrganization:_______________________________________Note:Apriceforanydonatedorfreematerialsshouldbeincludedinthebreakdown.Thisinformationsheetshouldbecompletedpriortothecompetition.

Whatisthegrainsizerangeofthesample?Usethecostinformationforonelightweightfillcubetoestimatewhatitwouldcosttoconstructaroadwayembankmentthatrequires100,000cubicyardsoflightweightfill.$_______________

Material(recycledcomponents&

bindingmaterial)%Volume %

Weight

UnitCost(perft3ofLWfill)

SubTotal(for8ft3ofLW

fill)

TOTAL

ScoringSummarySheetASCEStudentOrganization:_______________________________________

MaterialBreakdownandJustificationStatement Score1.Totalcost

o Lowcost=15pointso Averagecost=10pointso Highcost=5points

/15

2.Estimatecostfor100,000cubicyards /5

3.Justificationstatement /20Cost&ConstructabilitySub-Total /40

MaterialProperties Score1.Unitweight

o Ultra-Lightweight(lessthan3lb/ft3)=10pointso Lightweight(3.00-10.00lb/ft3)=5pointso Greaterthan10lb/ft3=0points

/10

2.Maximumstrengtho 3000-4000lb/ft2=15pointso 1500-2999lb/ft2=10pointso 250–1499lb/ft2=5pointso Lessthan250lb/ft2=0points

/15

3.Young’sModuluso Allresultswillbesplitintoquartilesandscoredaccordingly:o 1stQuartile(highestvalues):10pointso 2ndQuartile:7.5pointso 3rdQuartile:5pointso 4thQuartile(lowestvalues):2.5points

/10

4.Weight/LoadRatioo Allresultswillbesplitintoquartilesandscoredaccordingly:o 1stQuartile(lowestvalues):20pointso 2ndQuartile:15pointso 3rdQuartile:10pointso 4thQuartile(highestvalues):5pointso Ifcompressiveload<1000lb:0points

/20

5.FailureMode

o Cubedeformed,thenregainedoriginalshape=5pointso Cubedeformed,didnotregainoriginalshape=2.5pointso Catastrophicfailure=0points

/5

7.BONUS:Mostcreativematerial(judges’choice) /5

MaterialPropertiesSub-Total /60Cost&ConstructabilitySub-Total /40

OverallScore /100