道路工程材料申爱琴版作业集料水泥英文版.docx
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道路工程材料申爱琴版作业集料水泥英文版
AssignmentforRoadEngineeringMaterials
Chapter1&Chapter2
Name:
Class:
NO.:
SCHOOLOFHIGHWAYCOLLEGE
CHANG’ANUNIVERSITY
OCTOBER31,2013
ChapteroneAggregate
1.Herearetwokindsofstone,andthetestresultsareshowninfollowingtable.Whichkindofstonehasbetterperformance?
Solution:
Step1,theporosityofthesetwostonecanbecalculatedasthefollowingformula:
Andthe
.
Step2,thevaluesaturation-watercoefficientofAstoneis0.75,whichishigherthantheBstone’s,0.65.
Step3,thehigherporosityofstoneis,thebetterwaterabsorptiongetsandtheworsefrostresistanceis.Soisthesaturation-watercoefficient.Fromwhathasbeenmentionedabove,thestoneAapparentlygetsahigherporosityofstoneandsaturation-watercoefficient,sothestoneAisworseatfrostresistance.
Conclusion:
stoneBhasbetterperformance.
2.Pleasedescribethedifferencebetweenstrengthindexesofstoneandaggregate,andthetestmethods.
Solution:
a)Themajorstrengthindexforstoneisuniaxialcompressivestrength.Theresultofmeasuringuniaxialcompressivestrengthtestisrepresentedasresilientmodulus
withtriaxialchamberwithexternalLVDT’sandloadcell.Andthepreparesamplecanbecube(inroadengineering)orcylinder(inbridgeengineering).
b)Themajorstrengthindexforaggregateiscrushingvalue.Andthetestmethodisinthebelow.
ProceduretodetermineAggregateCrushingValue
i)Theaggregatespassingthrough12.5mmandretainedon10mmISSieveareoven-driedatatemperatureof100to110oCfor3to4hrs.
ii)Thecylinderoftheapparatusisfilledin3layers,eachlayertampedwith25strokesofatampingrod.
iii)Theweightofaggregatesismeasured(Weight‘A’).
iv)Thesurfaceoftheaggregatesisthenleveledandtheplungerinserted.Theapparatusisthenplacedinthecompressiontestingmachineandloadedatauniformratesoastoachieve40tloadin10minutes.Afterthis,theloadisreleased.
v)Thesampleisthensievedthrougha2.36mmISSieveandthefractionpassingthroughthesieveisweighed(Weight‘B’).
vi)Twotestsshouldbeconducted.
Aggregatecrushingvalue=(B/A)x100%.
3.Pleasedescribetheclassificationofaggregatefromdeferentperspectives
Solution:
Solution:
Notification:
Thereissomeothertypesofaggregatebydifferentstandards
●Crashedgravel
●Crushedsand
●Stonechip
●Filler
●Slag
4.Therearetwokindsofaggregate,andthetestresultsareshowninfollowingtable.Pleasedescribethedifferenceoftheperformanceofthesetwokindsofaggregate.
Solution:
Thelowercrushingvalueis,thebetteranti-crushingperformanceaggregategets.AndsoistheLosAngelesabrasionration.So,theaggregateBhasabetteranti-crushingandanti-crushingandabrasivenessperformance.
Thehigherpolishingvalueis,thebetteranti-slipperformanceaggregategets.So,theaggregateAhasabetteranti-slipperformance.
5.Pleasedescribethedefinition,thetestandthecalculationmethodsofdensitiesofaggregate,andgivetherankofdifferentdensities.
Solution:
a)Truedensity:
Definition:
themassofaunitvolumeoftheimpermeableportionofmaterial,includingthesolidandimpermeablepore..
Test:
LeChatelierflaskmethod
Calculationmethod:
b)Apparentdensity:
Definition:
themassofaunitvolumeoftheimpermeableportionofmaterial,includingthesolidandimpermeablepore.
Test:
Wirebasketmethods
Calculationmethod:
c)Bulkdensity:
Definition:
themassofaunitvolumeofmaterialundernaturalstatus,includingsolid,permeableandimpermeablepores.
Test:
Wirebasketmethodsforcoarseaggregate
Flaskmethodforfineaggregate
Calculationmethod:
d)Stackingdensity:
Definition:
drymassperunitvolumeofaggregateundersomestackingmethods.
including:
Loosedensity,Tampingdensity,Compactiondensity
Calculationmethod:
Rank:
6.
ThegradationcurvesofthreekindsofaggregateareshowinrightFig.Pleasejudgethegradationcategories,andthestructureofasphaltmixtureconsistedoftheseaggregate
Solution:
GradationAisthegapgradation.Oneormoreintermediateparticlesizesaggregatesaremissing.
GradationBisthecontinuousgradation.Theparticlesdistributeoneachsievesizefromthelargetosmall.
GradationCistheopengradation.Theparticlesdistributeonlargersievesize.
7.DiscussthedifferencesbetweengradationandfinenessmodulusoffineaggregateHavesandAandsandB,whichhavethesamefinenessmodulus,thesamegradation?
Solution:
Gradation,theparticlesizesandsizedistribution,referstotheproportionbymassorweightofaggregateparticlesdistributedinspecialparticle-sizeranges,notonlytoindividualfineandcoarseaggregate,butalsotothecombinedormixedaggregate
Finenessmodulus,avalue