砂石级配的测定英文版Word文件下载.docx

砂石级配的测定英文版Word文件下载.docx

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20℃

Airhumidity:

60%

atmospheric 

pressure:

100.92KPa

Introduction

Aimofexperiment：

Learnhowtodeterminethedistributionofsand,andcalculate

thegradationandfinenessmodulusofsand.

ExperimentPrinciples:

Sand，whoseparticlesizeislessthan5mm，isfineaggregatein

concrete.Sandcanbedividedintothreetypes,namednaturalsand,artificial

sandandmixedsand.sandarerequiredtohaveagoodgradingandcertain

finenessmodulusinordertoimprovetheworkabilityofconcrete.Thegrading

ofsandrepresentsthedistributionofsand’sgrainsize.Anunreasonablesand

gradingresultintheincreaseofcementdosageinunitvolumeconcreteand

thedecreaseofconcreteworkability.Thedegreeoffinenessmodulusrepresentsthedegreeofsandthickness.Sandwhosefinenessmodulusisgreaterthan3.7orlessthan0.7isnotusedforconcrete.Thesmallerthefinenessmodulusofsandis,themorecementwillbeusedwhentheconcertaremixedup.Sievingmethodareusuallyusedtotestthegradingofsand.Aseriesofsieveswhosemeshsizearedifferentareusedwhentestingsand

gradationbythemethodofsieving.themeshsizeofthesievesinclude

4.75mm,2.36mm,1.18mm,0.60mm,0.30mm,0.15mm,0.075mm.Thes

andsamplegothroughthesievesinorder.Wehavetoweighthesand

remainedineverysieves.Thancalculatethepercentageofsinglescreened

residue（a1.a2.a3.a4.a5.a6.a7）andpercentageofcumulativescreenedresidue（A1.A2.A3.A4.A5.A6.A7）.Thanwecangetthegradationandfinenessmodulusofsand.Thefollowingareformulasforthegradationandfinenessmodulusofsand.

Thegradationofsand:

a=m/M

4.75mm

m1

a1

A1=a1

2.36mm

m2

a2

A2=a1+a2

1.18mm

m3

a3

A3=a1+a2+a3

0.60mm

m4

a4

A4=a1+a2+a3+a4

0.30mm

m5

a5

A5=a1+a2+a3+a4+a5

0.15mm

m6

a6

A6=a1+a2+a3+a4+a5+a6

0.075mm

M7

a7

A7=a1+a2+a3+a4+a5+a6+a7

Finenessmodulusofsand:

U=[（A2+A3+A4+A5+A6）-5A1]／（100-A1）

Measurement 

Procedures 

1.Take1100gramsofsand,andputthemintotheoventodrythemupat105degreesCelsius 

.Ittakesabout15-20minutes.

Thenscreenthedrysandinsievewhosemeshis9.50mm.Dividetherestsandintotwopartsthatwillbeusedlater.

2.take500gramsofsandthathavebeendriedup,accuratetowithin1gram.Thenputthesampleonthesievessortedbymeshsizefromlargesttosmallestandsievethemout.

3.Putthesieveswithsandinthesieveshaker.Thanopenthesieveshaker.Shutdownthesieveshaker10minuteslaterandthantakethesieveswithsanddown.Afterthisprogress,thesievesshouldbescreenedbyhandfromthelargestonetothesmallestone.

4.Weightheremainedsandineverysieveandrecordthem 

inthetable.Ifthesieveresidueismorethan200grams,thesampleshouldbedividedintotwopartstobescreenedonemoretime.

5..Thancalculatethepercentageofsinglescreenedresidue,percentageofcumulativescreenedresidueandfinenessmodulusofsand.

6.Twoexperimentsshouldbedonetotaketheaverage,Ifthesumofremainedsandislessthan495grams,Anotherexperimentshouldbedone.

Equipment 

and 

Experimental 

Setup

1.Blastoven

2.Balance（accurateto0.001grams）

3.enameldiscandbrush

4.sieveshaker

5.sieves（meshsize:

4.75mm.2.36mm.1.18mm.0.60mm.0.30mm.0.15mm.0.075mm）

DatarecordsandDataprocessing

Thetableofexperimentaldatarecords

9.50mmsieveallowance10g

Screenresiduepercentage

Thesizeofsieve’shole

4.75

2.36

1.18

0.60

0.30

0.15

0.075

Group1

M

41

19

136

105

88

91

9

10

percentageofsinglescreenedresidue

8.2%

3.8

%

27.2%

21.0%

17.6

18.2

1.8

20

percentageofcumulativescreenedresidue

12.

0%

39.2%

60.2%

77.8

96

97.8%

99.8%

finenessmodulus

2.66

Group

2

Sieveallowance

135

106

89

27.0%

21.2%

17.8%

18.2%

2.0

12.0%

39.0%

78.0%

96.2%

98.0%

100

a1=41÷

500=8.2%

a2=19÷

500=3.8%

a3=136÷

500=27.2%

a4=105÷

500=21.0%

a5=88÷

500=17.6%

a6=91÷

500=18.2%

a7=9÷

500=1.80%

A1=a1=8.2%

A2=a1+a2=8.2%+3.8%=12.0%

A3=a1+a2+a3=8.2%+3.8%+27.2%=39.2%

A4=a1+a2+a3+a4=8.2%+3.8%+27.2%+21.0%=60.2%

A5=a1+a2+a3+a4+a5=8.2%+3.8%+27.2%+21.0%+17.6%=77.8%

A6=a1+a2+a3+a4+a5+a6=8.2%+3.8%+27.2%+21.0%+17.6%+18.2%=96.0%

u1=