Project on Concrete Mix Design for various grades of Concrete
Data required for mix design
1) Grade of concrete :- M35
2)Max. size of agg.:- 20 mm
3) Min. cement content :- 320kg
4) max. w/c ratio:- 0.45
5) Workability of slump :- 100mm
6) Exposure condition :- Sever
7) Max. cement content :- 450 kg
8) Type of agg. :- Angular
9) Addmixture :- Superplastisizer
10) Specific gravity of material
cement :- 3.15
coarse agg.:- 2.74
fine agg.:- 2.74
fly ash :- 2.2
Procedure :-
1 . Target mean strength
fck'= fck + 1.65 S
= 35 + 1.65 x5
= 43.25 N/mm2
2. Selection of w/c ratio
The max. w/c ratio is 0.45 we can take 0.4 w/c
3. Selection of water content
for 20 mm agg we can take 186 lit/m3 water and slump in between 25 to 50 mm we cant add the water but above 50 mm , for every 25mm we can add 3% of water , here 50 mm slump increase so we can add 6% of water
= 186 +6/100x186
= 197.16 lit
using superplastisizer we can reduce water content 29%
= 197.16 x 0.71
=139.98 i.e 140 lit
4. Calculation of cement and fly ash content
water cement ratio = 0.4
Cementious material content ( cement + fly ash)= 140/0.4
= 350 kg
we take min cement content 320kg
hence 320kg < 350 kg ok
for project requirement we can increase 10% cementious material,also increase fly ash per project requirement
=350 x1.1
=385 kg/m3
now water cement ratio = 140/385
= 0.36
add 30% of fly in cementious material = 385 x 30/100
= 115 kg/m3
Cementious material content ( cement + fly ash) = 385
cement + 115 = 385
cement = 385-115.5
= 270 kg/m3
5. Volume of coarse and fine aggregate
from table no 3. volume of 20mm and fine agg. is confirming zoneI so w/c ratio 0.5=0.6
but present w/c is 0.4. It is lowered by 0.1 so volume of coarse agg.in aincresed by 0.02
now volume of coarse agg. = 0.02+.06
= 0.62
For pumpable concrete we can reduce 10% of value
volume of coarse agg.= 0.62 x 0.9
volume of coarse agg= 0.56
Volume of fine agg = 1- 0.56
= 0.44
6. Mix calculation
a) Volume of concrete = 1m3
b) volume of cement = mass of cement /sp.gravity of cement x 1/1000
= 270/3.15x1/1000
=0.086 m3
c) volume of fly ash = mass of Fly ash /sp.gravity of Fly ash x 1/1000
= 115/2.2x1/1000
=0.052 m3
d) Volume of water = mass of water /sp.gravity of water x 1/1000
= 140/1 x 1/1000
= 0.14m3
e) Volume of chemical = mass of chemical /sp.gravity of chemical x 1/1000
= 7/1.145 x 1/1000
= 0.007m3
where mass of chemical = 2% of cementious material
f) volume of all agg = a - ( b+c+d+e)
= 1- ( 0.086+0.052+0.14+0.007)
= 0.715 m3
g) Mass of coarse aggregate= f x volume of coarse agg. x specific gravity of coarse agg. x 1000
= 0.715 x 0.56 x 2.74 x 1000
= 1097 kg
h) Mass of fine aggregate= f x volume of fine agg. x specific gravity of fine agg. x 1000
= 0.715 x 0.44 x 2.74 x 1000
= 862 kg
Mix proportion
Cement = 270kg/m3
Fly ash = 115 kg/m3
Fine agg.= 862kg/m3
Coarse agg.=1097kg/m3
chemical = 7 kg/m3
i.e mix proportion is 270: 115:862:1097
i.e. 1:0.42:3.19:4.06
Data required for mix design
1) Grade of concrete :- M50
2)Max. size of agg.:- 20 mm
3) Min. cement content :- 320kg
4) max. w/c ratio:- 0.45
5) Workability of slump :- 100mm
6) Exposure condition :- Sever
7) Max. cement content :- 450 kg
8) Type of agg. :- Angular
9) Addmixture :- Superplastisizer
10) Specific gravity of material
cement :- 3.15
coarse agg.:- 2.74
fine agg.:- 2.74
water:- 1
Procedure :-
1 . Target mean strength
fck'= fck + 1.65 S
= 50 + 1.65 x5
= 58.25 N/mm2
2. Selection of w/c ratio
The max. w/c ratio is 0.45 we can take 0.4 w/c
3. Selection of water content
for 20 mm agg we can take 186 lit/m3 water and slump in between 25 to 50 mm we cant add the water but above 50 mm , for every 25mm we can add 3% of water , here 50 mm slump increase so we can add 6% of water
= 186 +6/100x186
= 197.16 lit
using superplastisizer we can reduce water content 29%
= 197.16 x 0.71
=139.98 i.e 140 lit
4. Calculation of cement
water cement ratio = 0.4
Cementious material content = 140/0.4
= 350 kg
we take min cement content 320kg
hence 320kg < 350 kg ok
5. Volume of coarse and fine aggregate
from table no 3. volume of 20mm and fine agg. is confirming zoneI so w/c ratio 0.5=0.6
but present w/c is 0.4. It is lowered by 0.1 so volume of coarse agg.in aincresed by 0.02
now volume of coarse agg. = 0.02+.06
= 0.62
For pumpable concrete we can reduce 10% of value
volume of coarse agg.= 0.62 x 0.9
volume of coarse agg= 0.56
Volume of fine agg = 1- 0.56
= 0.44
6. Mix calculation
a) Volume of concrete = 1m3
b) volume of cement = mass of cement /sp.gravity of cement x 1/1000
= 350/3.15x1/1000
=0.111 m3
c) Volume of water = mass of water /sp.gravity of water x 1/1000
= 140/1 x 1/1000
= 0.14m3
d) Volume of chemical = mass of chemical /sp.gravity of chemical x 1/1000
= 7/1.145 x 1/1000
= 0.007m3
where mass of chemical = 2% of cementious material
e) volume of all agg = a - ( b+c+d+e)
= 1- ( 0.111+0.14+0.007)
= 0.742 m3
f) Mass of coarse aggregate= f x volume of coarse agg. x specific gravity of coarse agg. x 1000
= 0.742 x 0.56 x 2.74 x 1000
= 1138 kg
g) Mass of fine aggregate= f x volume of fine agg. x specific gravity of fine agg. x 1000
= 0.742 x 0.44 x 2.74 x 1000
= 894 kg
Mix proportion
Cement = 350kg/m3
Fine agg.= 894kg/m3
Coarse agg.=1138kg/m3
chemical = 7kg/m3
i.e mix proportion is 350:894:1138
i.e. 1:2.55:3.25