thickness and particle size

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1、ThicknessandparticlesizeFirst,thedegreeofthicknessandgranularity:1)?????????????????????Thethicknessandgranularityof9:Sizeofsand:thesizeoftheaverageparticlesizeofthegranuleswithdifferentgrainsizes.Usually,thevalueisnotequaltotheaverageparticlesize,bu

2、tcanaccuratelyreflectthethicknessofthesand.ThelargerthedegreeoffinemodulusMx,thethickerthesand,thesmallerthetotalsurfacearea(orthesurfacearea)oftheunitweight;ThesmallertheMx,thebiggerthesandis.Particlegradingofsand:theratioofsandgrainstodifferentgrai

3、nsizes.Goodgradingreferstothegapofthecoarseparticleisrightbythegrainfilling,theparticlesjustbyfineparticlesfillthegap,sostagefillingsand(asshowninfigure4-1)toformtheaccumulationofthefineandclosecondition,thevoidfraction,thelowestbulkdensityreachesthe

4、maximumvalue.Thiswillachievethegoalofsavingcementandimprovingtheoverallperformanceofconcrete.Therefore,theparticlesizeofthesandparticlereflectsthesizeofthegap.Thethicknessofsandandthesizeoftheparticlesizearemeasuredbythesieveanalysismethod,andthedegr

5、eeofthicknessisindicatedbythedegreeoffinenessmodulus,andthegradingareaisusedtoindicatethegradingofsand.Accordingtothebuildingsand"(GB/T14684-2001),sieveanalysisistouseanapertureof5.00,2.5,1.25,0.63,0.315,0.160mmstandardscreen,willbe500gramsofdrysandf

6、romcoarsetofinesieveinturn(seetest),weighingthesievesieveallowancemi(g),calculatethesinglescreenresidueonsieverate(%),theai(eachsievesieveallowanceonthepercentageofthetotalweightsample),tocalculatethecumulativerateoftriageai(%)(thickerthanthescreenan

7、dvariousscreenofthesumofallpercentagepointsmorethanmeterscreenscreen).Thecomputationalrelationshipbetweenaiandaiisshownintable4-3.Table4-3?ThecalculationrelationshipbetweenthesieveresidueandthemetersieveiscalculatedScreensize(mm)Sieveallowance(g)Mete

8、r(%)Cumulativescreen(%)5.00m12.50m21.25Them30.630Them40.315Them50.160m6chassisMlowThefinenessmodulusiscalculatedfromthefollowingcalculation(to0.01):ScalethesandaccordingtothesizeofthesizeMx:Mx>3.7?Coarsesand;Mx=3.1~3.7coarsesand;Mx=3.0~2.3middlesand;