Project on Concrete Mix Design for various grades of Concrete

AIM

CALCULATE THE CONCRETE MIX DESIGN FOR M35 GRADE CONCRETE WITH FLY ASH

CALCULATE THE CONCRETE MIX DESIGN FOR M50 GRADE CONCRETE WITHOUT FLY ASH

PROCEDURE:

1)STIMULATION FOR PROPORTIONING

A) GRADE DESTIGNATION:M35

B)TYPE OF CEMENT:OPC 43 GRADE IS 8112-1989

C)MINIMUM NOMINAL SIZE OF AGGREGATE :20MM

D)MINIMUM CEMENT CONTENT:320KG/m3(FROM TABLE 5 OF IS 456:2000-EXPOSURE CONDITION)

E)MAXIMUM WATER CEMENT RATIO:0.45(FROM TABLE 5 OF IS 456:2000-EXPOSURE CONDITION)

F)WORKABILITY:100MM(SLUP VALUE FOR PUMPABLE CONCRETE)

G)TYPE OF MINARAL ADMIXTURE:FLY ASH (IS 3812)(PART1)

H)EXPOSURE CONDITION :SEVERE(FOR REINFORCED CONCRETE)

I)METHOD OF CONCRETE PLACING :PUMPING

J)DEGREE OF SUPERVISION :GOOD

K)TYPE OF AGGREGATE:CRUSHED ANGULAR AGGREGATE

L)MAXIMUM CEMENT CONTENT :450KG/mm3

M)CHEMICAL ADMIXITURE TYPE :SUPER PLASTICIZER(IS9103)

TEST DATA FOR MATERIAL

A) CEMENT USED :OPC 43 GRADE (IS 8112:1989)

B)SPECIFIC GRAVITY OF CEMENT:3.15

C)SPECIFIC GRAVITTY OF FLY ASH:2.2

D)CHAMICAL ADMIXTURE :SUPER PLASTICIZER (IS 9103)

E)SPECIFIC GRAVITY OF

1)COARSE AGGREGATE:2.74

2)FINE AGGREGATE:2.74

F)WATER ABSORPTION:

1)COARSE AGGREGATE:0.5%

2)FINE AGGREGATE:1%

G)FREE SUREFACE MOISTURE:

1)COARSE AGGREGATE:NILL

2)FINE AGGREGATE :NILL

H)SIEVE ANALYSIS:

1)COARSE AGGREGATE:CONFORMING TO ALL IN AGGREGATE TO TABLE 2 OF IS 383

2)FINE AGGREGATE:CONFORMATION TO GRADING ZONE 1 OF TABLE 4 OF IS 383

CALCULATION

STEP:1 TARGATE MEAN STRENGTH FOR MIX PROPORTION

Ft=Fck+1.65S

WHERE

Ft:TARGET AVERAGE COMPRESSIVE STRENGTH AT 28 DAYS

Fck=CHARACTERISTICS COMPRESSIVE STRENGTH AT 28 DAYS

S:STANDARED DEVIATION

(FROM TABLE 1 OF IS 10262:2009 S IS 5N/mm2)

therfore,

Ft=35+1.65*5

=43.25N/mm2

STEP:2 SELECTION OF WATER -CEMENT RATIO

FROM TABLE 5 OF IS 456 FOR SEVERE EXPOSURE CONDITION MAXIMUM WATER CEMENT RATIO IS :0.45

BASED ON EXPERIENCE ADOPTED MAXIMUM WATER CEMENT RATIO IS 0.42

0.42<0.45 HENCE OK

STEP :3 SELECTION OF WATER CONTENT

FROM TABLE 2 OF IS 10262:2009 MAXIMUM WATER CONTENT FOR 20 MM AGGREGATE =186 LITER (FOR 25 TO 50 MM SLUMP RANGE)

ESTIMATED WATER CONTENT FOR 100 MM SLUMP:

186+6/100*186

197 LITER

BASED ON TRIALS WITH SUPER PLASTISIZER WATER CONTENT REDUCTION IS 29% HAS BEEN ACHIVED HENCE THE ARRIVED WATER CONTENT

=197*0.71

=140 LITER

STEP:4 CALCULATION OF CEMENT CONTENT

ADOPTED W/C RATIO =0.42

CEMENT CONTENT=140/0.42

=333KG/m3

FROM TABLE 5 OF IS 456 MINIMUM CEMENT CONTENT FOR SEVER EXPOSURE CONDITION IS 320KG/m3

=333>320KG/m3 HENCE OK

NOW TO PROPORTION TO MIX CONTAINNG FLAY ASH THE FOLLOWING STEP ARE SUGGESTED

A)THE PERCENTAGE OF FLY ASH NEED TO BE DECIDE BASED ON PROJECT REQUIREMENT AND QUALITY OF MATERIAL

B) IN SOME CASES INCREASE IN CEMENTITIOUS MATERIAL CAN BE WARRETED INCREASE IN CIMENTITIOUS MATERIAL CONTENT AND ITS PERCENTAGE MAY BE BASED ON EXPERIENCE MAY BE BASED ON EXPERIENCE AND TRAIL HERE WILL TAKE INCREASE OF 10% CEMENTITIOUS MATERIAL CONTENT.

CEMENTITIOUS MATERIAL CONTENT

=333*1.10

=366KG/m3

WATER CONTENT IS 140 KG/m3

SO NEW W/C RATIO IS

=140/366

=0.38

FIY ASH@30% OF CEMENTITIOUS MATERIAL=366*30/100

=110KG/m3

CEMENT =366-110

=256KG/m3

SAVING OF CEMENT WHILE USING FLY ASH=333-256

=77KG/m3

FLY ASH UTILIZED =110KG/m3

STEP:5 PROPORATION OF VOLUME OF COARSE AND FINR AGGREGATE CONTENT

FROM TABLE 3 IS 10262:2009 VOLUME OF COARSE AGGREGATE CORRESPONDING TO 20 MM SIZE AGGREGATE AND FINE AGGREGATE (ZONE 2) FOR WATER CEENT RATIO OF 0.62

IN HE PRESENT CASE WATER CEMENT RATIO IS 0.42

THERE FOR VOLUME OF COARSE AGGREGATE IS REQUIRED TO BE INCREASED TO DECEASE THE FINE AGGREGATE COTENT

[0.5-W/C/0.05*0.01]+VOLUME

=[0.5-0.42/0.05*0.01]+0.62

=0.64

FOR PUMPABLE CONCRETE THESE VALUE SHOULD BE REDUCED UP TO 10%

THERE FOR VOLUME OF COARSE AGGREGATE IS

=0.64*0.9

=0.576

VOLUME OF FINE AGGREGATE CONTENT

=1-0.576

=0.424

STEP:6 MIX PROPORTION

A)VOLUME OF CONCRETE :1m3

B)VOLUME OF CEMENT=[MASS OF CEMENT/SPECIFIC GRAVITY OF CEMENT]*1/1000

=[256/3.15]*1/1000

=0.081m3

C)VOUME OF FLY ASH =[MASS OF FLY ASH/SPECIFIC GRAVITY OF FLY ASH]*1/1000

=[110/2.2]*1/1000

=0.05m3

D)VOLUME OF WATER =[MASS OF WATER/SPECIFIC GRAVITY OF WATER]*1/1000

=[140/1]*1/1000

=0.140m3

E) VOLUME OF CHEMICAL ADMIXTURE:[MASS OF CHAMICAL ADMIXTURE/SPECIFIC GRAVITY OF ADMIXTURE]*1/1000

2% OF CEMENTITIOUS MATERIAL

[366*2/100]

=7.32

THEREFORE

=[7.32/1.145]*1/1000

=0.006m3

F) VOLUME OF ALL IN AGGREGATE=[A-(B+C+D+E)]

=[1-(0.081+0.05+0.140+0.006)]

=0.723m3

G) MASS OF COARSE AGGREGATE=F*VOLUME OF COARSE AGGREGATE*SPECIFIC GRAVITY OF COARSE AGGREGATE*1000

=0.723*0.576*2.74*1000

=1141KG/m3

H) MASS OF FINE AGGREGATE=F*VOLUME OF FINE AGGREGATE*SPECIFIC GRAVITY OF FINE AGGREGATE*1000

=0.723*0.424*2.74*1000

=840KG/m3

MIX PROPORATION TRIAL 1

CEMENT:256KG/m3

FLYASH:110KG/m3

WATER:140KG/m3

FINE AGGREGATE:840KG/m3

COARSE AGGREGATE:1141KG/m3

CHEMICAL ADMIXTURE:7.32KG/m3

WATER CEMENT RATIO:0.42

MIX PROPORTION BY WEIGHT: C:F.A:C.A

=1:2.29:3.12

ANS: CALCULATION FOR M50 GRADE WITHOUT FLY ASH

1)STIMULATION FOR PROPORTIONING

A) GRADE DESTIGNATION:M50

B)TYPE OF CEMENT:OPC 53 GRADE IS 8112-1989

C)MINIMUM NOMINAL SIZE OF AGGREGATE :20MM

D)MINIMUM CEMENT CONTENT:320KG/m3(FROM TABLE 5 OF IS 456:2000-EXPOSURE CONDITION)

E)MAXIMUM WATER CEMENT RATIO:0.45(FROM TABLE 5 OF IS 456:2000-EXPOSURE CONDITION)

F)WORKABILITY:100MM(SLUP VALUE FOR PUMPABLE CONCRETE)

G)TYPE OF MINARAL ADMIXTURE:FLY ASH (IS 3812)(PART1)

H)EXPOSURE CONDITION :SEVERE(FOR REINFORCED CONCRETE)

I)METHOD OF CONCRETE PLACING :PUMPING

J)DEGREE OF SUPERVISION :GOOD

K)TYPE OF AGGREGATE:CRUSHED ANGULAR AGGREGATE

L)MAXIMUM CEMENT CONTENT :450KG/mm3

M)CHEMICAL ADMIXITURE TYPE :SUPER PLASTICIZER(IS9103)

TEST DATA FOR MATERIAL

A) CEMENT USED :OPC 53 GRADE (IS 8112:1989)

B)SPECIFIC GRAVITY OF CEMENT:3.15

C)CHAMICAL ADMIXTURE :SUPER PLASTICIZER (IS 9103)

D)SPECIFIC GRAVITY OF

1)COARSE AGGREGATE:2.74

2)FINE AGGREGATE:2.74

E)WATER ABSORPTION:

1)COARSE AGGREGATE:0.5%

2)FINE AGGREGATE:1%

F)FREE SUREFACE MOISTURE:

1)COARSE AGGREGATE:NILL

2)FINE AGGREGATE :NILL

G)SIEVE ANALYSIS:

1)COARSE AGGREGATE:CONFORMING TO ALL IN AGGREGATE TO TABLE 2 OF IS 383

2)FINE AGGREGATE:CONFORMATION TO GRADING ZONE 1 OF TABLE 4 OF IS 383

CALCULATION

STEP:1 TARGATE MEAN STRENGTH FOR MIX PROPORTION

Ft=Fck+1.65S

WHERE

Ft:TARGET AVERAGE COMPRESSIVE STRENGTH AT 28 DAYS

Fck=CHARACTERISTICS COMPRESSIVE STRENGTH AT 28 DAYS

S:STANDARED DEVIATION

(FROM TABLE 1 OF IS 10262:2009 S IS 5N/mm2)

therfore,

Ft=50+1.65*5

=58.25N/mm2

STEP:2 SELECTION OF WATER -CEMENT RATIO

FROM TABLE 5 OF IS 456 FOR SEVERE EXPOSURE CONDITION MAXIMUM WATER CEMENT RATIO IS :0.45

BASED ON EXPERIENCE ADOPTED MAXIMUM WATER CEMENT RATIO IS 0.39

0.39<0.45 HENCE OK

STEP :3 SELECTION OF WATER CONTENT

FROM TABLE 2 OF IS 10262:2009 MAXIMUM WATER CONTENT FOR 20 MM AGGREGATE =186 LITER (FOR 25 TO 50 MM SLUMP RANGE)

ESTIMATED WATER CONTENT FOR 100 MM SLUMP:

186+6/100*186

197 LITER

BASED ON TRIALS WITH SUPER PLASTISIZER WATER CONTENT REDUCTION IS 29% HAS BEEN ACHIVED HENCE THE ARRIVED WATER CONTENT

=197*0.71

=140 LITER

STEP:4 CALCULATION OF CEMENT CONTENT

ADOPTED W/C RATIO =0.39

CEMENT CONTENT=140/0.39

=359KG/m3

FROM TABLE 5 OF IS 456 MINIMUM CEMENT CONTENT FOR SEVER EXPOSURE CONDITION IS 320KG/m3

=359>320KG/m3 HENCE OK

STEP:5 PROPORATION OF VOLUME OF COARSE AND FINR AGGREGATE CONTENT

FROM TABLE 3 IS 10262:2009 VOLUME OF COARSE AGGREGATE CORRESPONDING TO 20 MM SIZE AGGREGATE AND FINE AGGREGATE (ZONE 2) FOR WATER CEENT RATIO OF 0.62

IN HE PRESENT CASE WATER CEMENT RATIO IS 0.39

THERE FOR VOLUME OF COARSE AGGREGATE IS REQUIRED TO BE INCREASED TO DECEASE THE FINE AGGREGATE COTENT

[0.5-W/C/0.05*0.01]+VOLUME

=[0.5-0.39/0.05*0.01]+0.62

=0.64

FOR PUMPABLE CONCRETE THESE VALUE SHOULD BE REDUCED UP TO 10%

THERE FOR VOLUME OF COARSE AGGREGATE IS

=0.64*0.9

=0.576

VOLUME OF FINE AGGREGATE CONTENT

=1-0.576

=0.424

STEP:6 MIX PROPORTION

A)VOLUME OF CONCRETE :1m3

B)VOLUME OF CEMENT=[MASS OF CEMENT/SPECIFIC GRAVITY OF CEMENT]*1/1000

=[359/3.15]*1/1000

=0.113m3

C)VOLUME OF WATER =[MASS OF WATER/SPECIFIC GRAVITY OF WATER]*1/1000

=[140/1]*1/1000

=0.140m3

D) VOLUME OF CHEMICAL ADMIXTURE:[MASS OF CHAMICAL ADMIXTURE/SPECIFIC GRAVITY OF ADMIXTURE]*1/1000

2% OF CEMENTITIOUS MATERIAL

[366*2/100]

=7.18

THEREFORE

=[7.18/1.145]*1/1000

=0.006m3

E) VOLUME OF ALL IN AGGREGATE=[A-(B+C+D)]

=[1-(0.113+0.140+0.006)]

=0.741m3

F) MASS OF COARSE AGGREGATE=F*VOLUME OF COARSE AGGREGATE*SPECIFIC GRAVITY OF COARSE AGGREGATE*1000

=0.741*0.576*2.74*1000

=1169KG/m3

G) MASS OF FINE AGGREGATE=F*VOLUME OF FINE AGGREGATE*SPECIFIC GRAVITY OF FINE AGGREGATE*1000

=0.741*0.424*2.74*1000

=860KG/m3

MIX PROPORATION TRIAL 1

CEMENT:359KG/m3

WATER:140KG/m3

FINE AGGREGATE:860KG/m3

COARSE AGGREGATE:1169KG/m3

CHEMICAL ADMIXTURE:7.18KG/m3

WATER CEMENT RATIO:0.39

MIX PROPORTION BY WEIGHT: C:F.A:C.A

=1:2.39:3.25

RESULT:

MIX PROPORTION OF M35 GRADE OF CONCRETE WITH FLY ASH IS1:2.29:3.12 AND ITS W/C RATIO TO BE 0.42

MIX PROPORTION OF M50 GRADE OF CONCRETE WITHOUT FLY ASH IS1:2.39:3.25 AND ITS W/C RATIO TO BE 0.39