Project on Concrete Mix Design for various grades of Concrete

Concrete Mix Design for M35 grade concrete with fly ash

1.Stipulation for proprtioning

a.Grade designation : M35

b.Type of cement : OPC 43 grade conforming to IS8112

c.Type of mineral admixture : Fly ash conforming to IS3812(part 1)

d.Maximum nominal size of aggregate : 20mm

e.Minimum cement content : 320kg/m^3

f.Maximum water cement ratio :0.45

g.Workability : 100mm(slump value for pumpable concrete)

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/m^3

m.Chemical admixture type : Superplasticizer

2.Test data for materials:

a.Cement used : OPC 43 grade conforming to IS8112

b.Specific gravity of cement :3.15

c.Fly ash : Conforming to IS3812(part 1)

d.Specific gravity of fly ash : 2.2

e.Chemical admixture : Superplasticizer conforming to IS9103

f.Specific gravity of :

coarse aggregate : 2.74

fine aggregate : 2.74

g.Water absorption :

coarse aggregate :0.5%

fine aggregate :1.0%

h.Free surface moisture :

coarse aggregate : NIL

fine aggregate : NIL

i.Sieve analysis:

3.Target Strength for mix proportioning:

f'ck=fck + 1.65S

=35+1.65(5)

f'ck=43.25N/mm^2

4.Selection of water cement ratio:

From table 5 of IS456:2000 for serve exposure maximum water cement ratio=0.45

Based on exoerience adopt water cement ratio as 0.40

0.40<0.45,Hence ok

5.Selection of water content:

From table 2 of IS 10262: 2009, maximum water content for 20mm aggregare =186 litre (for 25mm to 50mm slamp range)

Estmate water contant for 100mm slamp=186+6/100x186=197 lit

As super plasticizer is used, the water content can be redued up to 30%

Based on trials water content reduction of 29% is achicred with plastieizer

Hence the arrived water content=197x0.71=140 litre

6.Calculation of cement content:

Water cement ratio=0.4

Cementitious material (cement & fly ash) content=140/0.4=350kg/m^3

From table 5 of IS 456 minimum cement content for severe exposure condition= 320 kg/m^3

350 kg/m^3> 320kg/m^3, Hence ok

Cementitious material content=350x1.10=385kg/m^3

Water content=140kg/m^3

So, water cement ratio =140/385=0.364

Fly ash @ 30% total cementitious material content=385x30%=115kg/m^3

Cement (opc) =385-115=270kg/m^3

Saving of cement while using fly ash =350-270=80kg/m^3 and

Fly ash being utilized =115kg/m^3

7. Proportion of volume of coarse aggregate and fine aggregate content:

From table 3 of IS 10262=2009, volume of coarse aggregate corresponding to 20mm size aggregate and fine aggregate (zone 1) for water -cement ratio=0.6

In the present case the water cement ratio is 0.40

There fore,corrected volume of coarse aggregate for the water-cement ratio of 0.40=0.62

For pumpable concrese these values are reduced by 10%

There for, volume of coarse aggregate=0.62x0.9=0.56

Volume of fine aggregate content=1.056=0.44

8.Mix calculation:

The mix calculation per unit volume of concrete shall be as follow

a) Volume of concrete = 1m^3

b) Volume of cement = mass of amount/ Spacifice gravity of amount x1/1000 =270/3.15x1/1000

=0.086m^3

c) Volume of fly ash = mass of fly ash/ specific gravity of fly ash x1/1000

= 115/2.2 x 1/1000

= 0.052m^3

d) Volume of water = mass of water / specifice gravity of water x 1/1000

= 140 / 1 x 1 / 1000

= 0.140 m^3

e) Volume of aggregate (FA + CA)=mass of chemical admixture/specific gravity of admixturex1/1000

= 7.6/1.145 x 1 / 1000

= 0.006m^3

f) Volume of aggregate (FA+CA) = ( a - ( b+c+d+c) )

= ( 1-(0.086 + 0.052 + 0.140 + 0.006) )

= 0.716m^3

g) Mass of coarse aggregate = f x volume of coarse aggregate x specific gravity of C.A x1000

= 0.716 x 0.56 x 2.74 x 1000

= 1098kg/m^3

h) Mass of fine aggregate = f x volume of fine aggregate x specific gravity of F.A x 1000

= 0.716 x 0.44 x 2.74 x 1000

= 863 kg/m^3

9. Mix Proportions for trial number 1 :

Cement = 270kg/m^3

Fly ash = 115 kg/m^3

Water = 140 kg/m^3

Fine aggregate = 868 kg /m^3

Coarse aggregate = 1098 kg/m^3

Chemical admixture = 7 kg/m^3

Water cement ratio = 0.364

Mix ratio = 1: 2.24: 2.85

Concrete Mix Design for M50 grade concrete without flyash

1.Stipulations of proportationing:

a.Grade designation :M50

b.Type of cement :OPC 43 grade conforming to IS 8112

c.Maximum nominal size of aggregate: 20mm

d.Minimum cement content :320Kg/m^3

e.Maximum water cement ratio :0.45

f.Workability :100mm

g.Exposure condition :Severe

h.Method of concrete placing :Pumping

i.Degree of supervision :Good

j.Type of aggregate :crushing angular aggregate

k.Maximum cement content :450Kg/m^3

l.Chemical admixture type : Superplasticizer

2.Test data for material:

a.Cement used : OPC 43 grade conforming to IS 8112

b.Specific gravity of cement :3.15

c.Chemical admixture :Superplasticizer conforming to IS9103

d.Specific gravity of:

Coarse aggregate:2.74

Fine aggregate :2.74

e.Water absorption:

Coarse aggregate :0.5%

Fine aggregate :1.0%

f.Free surface moisture :

Coarse aggregate :Nil

Fine aggregate :Nil

i.Sieve analysis:

3.Target strength for mix proportioning:

f'ck=fck+1.65S

= 50+1.65(5)

f'ck=58.25N/mm^2

4.Selection of water cement ratio :

From table 5 of IS456:2000 for severe exposure maximum water cement ratio=0.40

Based on experience adopted water cement ratio is 0.40

Hence ok

5.Selection of water content:

From table2 of IS10262:2009,maximum water content for 20mm aggregate=186litre(for 25mm to 50mm slump range)

Estimated water content for 100mm slump=186+6/100 x 186=197 litre

As superplasticizer is used the water content can be reduced up to 20% and above

Based on trails water content reduced of 29% is achieved with plasticizer

Hence the arrived water content =197x0.71=140litre

6.Calculation of cement content:

water cement ratio:0.4

Cement contrent =140/0.4=350Kg/m^3

From table 5 of Is 456 minimum cement content for severe exposure condition=320Kg/m^3

350Kg/m^3>320Kg/m^3

Hence ok

7.Proportion of volume of coarse aggregate and fine aggregatr content:

From table 3 of IS10262:2009 volume of coarse aggregate correponding to 20mm size aggregate and fine aggregate for water cement ratio=0.6

In the present case the water cement ratio is 0.40

Therfore corrected volume of coarse aggregate for the water cement ratio of 0.40=0.62

For pumpable concrete these values are reduced by 10%

Therefore volume of coarse aggregate=0.62x0.9=0.56

volume of fine aggregate content=1-0.56=0.44

8.Mix calculation:

The max calculation per unit volume of concrete shall be as follows

a. Volume of concrete = 1 m^3

b. Volume of cement = mass of cement / specific gravity of cement x 1/1000

= 350 / 3.15 x 1 / 1000 = 0.111m^3

c. Volume of water = mass of water / specific gravity of water x 1 / 1000

= 140 / 1 x 1 / 1000 = 0.140 m^3

d. Volume of chemical admixture = mass of chemical asmixture /specific gravity of admixture x 1 / 1000

= 7.6 / 1.145 x 1 / 1000 = 0.006m^3

e. Volume of aggregate (FA+CA) = (a- (b+c+d))

= (1-(0.111+0.140+0.006))

= 0.743m^3

f. mass of coarse aggregate = e x Volume of coarse aggregate x specific gravity of coarse aggr x 1000

= 0.743 x 0.56 x 2.74 x 1000

= 1140 kg/m^3

g. mass of fine aggregate = e x Volume of fine aggr x specific gravity of fine aggr x 1000

= 0.743 x 0.44 x 2.74 x 1000

= 896 kg/m^3

9.Mix proportions for trial number 1:

Cement = 350Kg/m^3

Water = 140Kg/m^3

fine aggregate =896Kg/m^3

Coarse aggregate =1140Kg/m^3

Chemical admixture =7Kg/m^3

Water cement ratio = 0.4

Trial mix ratio =1:2.56:3.26