Project on Concrete Mix Design for various grades of Concrete

MIX DESIGN FOR M35 GRADE CONCRETE WITH FLY ASH

 1.  TARGET MEAN STRENGTH

    F'ck= fck +1.65x s

   s = 5 N/mm2 from table 1 IS 10262:2009, standard deviation, s 

   fck = 35N/mm2

    F'ck = 35 +1.65 x5 =43.5N/mm2

2.  WATER CEMENT RATIO

assume atmospheric condition = extreme

tabel 5 - IS456 2000

at extreme the w/c ratio=0.40

M35= w/c ratio =0.45

since 0.40 is lesser than 0.45, the w/c ratio with better workability is 0.40

3. MINIMUM CEMENT CONTENT

360kg/m3 for 0.40 w/c ratio

water content = nominal size of aggregates = 20mm

table IS10262 2009

minimum water content = 186kg

slump ranges from 25 to 50mm

As superplasticizers(20% reduced= 100-20= 80%)

186x80%= 148.8 ~ water content , W= 149L

4. CEMENT + FLYASH

w/c ratio =0.40

W = 149kg

Cement + flyash =149/0.40 =372.5~ 370kg/m3

minimum cement content = 360kg/m3

360<370 , hence okay

increase by 10% = 370x0.10 +370 = 407kg/m3

W = 149kg,

water cement ratio =149/407= 0.366

flyash at 30%, total cementitious material content

= 407x30/100 = 122Kg/m3

cement = 407-122= 285kg/m3

saving for cement using fly ash= 370 -285 = 85kg/m3

fly ash =122kg/m3

5. VOLUME OF FINE AND COARSE AGGREGATES(FA AND CA)

FA -> ZONE 1 TABLE 4,  IS383 

CA -> TABLE 2 IS 383

nominal size of aggregates= 20mm

Fine aggregates Zone 1, therefore 

Volume of coarse aggregates = 0.60

water cement ratio = 0.4(+/-0.01 for every +/- 0.005)

so volume of CA =0.62

volume of FA = 1-0.62 =0.38

6. VOLUME OF CONCRETE =1m3

VOLUME OF CEMENT =285/3.15 X 1/1000 =0.090m3

VOLUME OF FLYASH =122/2.2 X 1/1000=0.055m3

VOLUME OF WATER =149/1 X 1/1000 =0.149m3

VOLUME OF ADMIXTURE =7.6/1.145 X 1/1000=0.006m3

VOLUME OF CA AND FA = a -(b+c+d+e)=1-(0.090+0.055+0.149+0.006)=0.7m3

MASS OF COARSE AGGREGATE =0.7X0.62X2.74X1000= 1189.16kg/m3

MASS OF FINE AGGREGATE =0.7X0.38X2.74X1000 =728 kg/m3

7. RESULTS

CEMENT =785kg/m3

FLYASH =122kg/m2

WATER =149 kg

COARSE AGGREGATE =1189 kg/m3

FINE AGGREGATE = 728 kg/m3

CHEMICAL ADMIXTURE = 7.6kg/m3

WATER CEMENT RATIO = 0.366

TRIAL MIX RATIO = 285 :728:1189 = 1:2.55:4.17 =C:FA:CA

trial mix ratio should match the workability , durability and minimum working strength of M35 grade concrete , if not further trials should be done.

 CONCRETE MIX DESIGN FOR M50 WITHOUT FLYASH

1. TARGET MEAN STRENGTH

F’ck = fck + 1.65 x  S …………………….. S= standard deviation from the table 1 IS10262:2009 = 5

= 50 +1.65 X 5 =58.25 N/mm2

2. WATER CEMENT RATIO

        TABLE 5 IS456:2000

        Extreme exposure condition ; W/C RATIO = 0.40

        M50 ; W/C =0.40

        Lower the ratio better the workability, there the w/c ratio = 0.40

       MINIMUM CEMENT CONTENT

        FOR M 50 -> 360 kg/m3

3. WATER CONTENT

Nominal size of aggregates = 20mm

Minimum water content  W= 186 L

Slump ranges from 25 – 50mm

As superplasticisers used , 20% reduced

100-20 =80%

186x80% =148.8 ~ water content = 149L

4. CEMENT CONTENT

 Water cement ratio = 0.4

  W = 149L

  CEMENT CONTENT =C = 149/0.40 =372.5 ~ 375 kg/m3

  Minimum cemnt content = 360kg/m3

 Since 360 <370, hence okay.

5. VOLUME OF COARSE AGGREGATE AND FINE AGGREGATE

  COARSE AGGREGATE = ZONE 1 TABLE 4 IS383

   FINE AGGREGATE = TABLE 2 IS383

   According to table 3 IS10262 :2009

   Nominal Size of aggregates =20mm

  Fine aggregates , Zone 1 ;

  Volume of coarse aggregate =0.60

Water cement ratio = 0.40

(+/-0.01 for every +/-0.005)

Volume of coarse aggregate = 0.62

Volume of fine aggregate =1-0.62 =0.38

6. MIX CALCULATION

VOLUME OF CONCRETE =1m3

VOLUME OF CEMENT =375/3.15 X 1/1000 =0.118m3

VOLUME OF WATER =149/1 X 1/1000 =0.149m3

VOLUME OF ADMIXTURE =7.6/1.145 X 1/1000=0.006m3

VOLUME OF CA AND FA = a -(b+c+d+e)=1-(0.118+0.149+0.006)=0.727m3

MASS OF COARSE AGGREGATE =0.727X0.62X2.74X1000= 1235.02kg/m3

MASS OF FINE AGGREGATE =0.727X0.38X2.74X1000 =756.9 kg/m3

7. RESULT

CEMENT =375 kg/m3

WATER =149 kg

COARSE AGGREGATE =1235 kg/m3

FINE AGGREGATE = 756.9kg/m3

CHEMICAL ADMIXTURE = 7.6kg/m3

WATER CEMENT RATIO = 0.40

TRIAL MIX RATIO = 375:757:1235= 1:2.01: 3.29=C:FA:CA

trial mix ratio should match the workability , durability and minimum working strength of M50 grade concrete , if not further trials should be done.