Project on Concrete Mix Design for various grades of Concrete
1.
concrete mix design for m 35 with fly ash
Data required:
Grade designation: m 35 with 10% of flyash
Type of cement: opc 43 grade confirming to IS 8112
Maximum nominal size of aggregate column 20 mm
exposure type: very severe
Minimum cement content column 340 kg per m^3
Walkability: 100 mm slump
Method of concrete placing: pumping
Type of aggregate: crashed angular
Maximum cement content call 450 kg per metre cube
Chemical admixture: superplasticizer
Sir gravity of cement: 3.15
Specific gravity of flyash: 2.2
specific gravity of fine aggregate column 2.61
specific gravity of coarse aggregate column 2.73
Course and fine aggregate: grade 1
target strength:
f'ck = fck+1.65s
s=5 from table 1 of IS 10262 2009
f'ck = 35+(1.65*5)=43.25N/mm^2
selection of water cement ratio:
From Table 5 IS:456-2000 for severe exposure condition maximum water cement ratio is 0.45
Adopt water cement ratio = 0.41
selection of water content:
Maximum water content = 186 liters from table 2, 10262- 2009
For 75mm slump, water content = 186 + (6/100)*186) ~ 197
super plasticiser reduces 29% of water content
Hence new water content = (71/100)*197 = 139.87
calculating cement content:
Water/cement = 0.41
cementitious content =139.87/0.41=341.14>340kg/m^3
Thefore cementitions content =341.14kg/m^
Here cement is replaced by 20% fly ash, therefore increase the total cementitious content by 10%
Cementitious content = 1.10*341.14 = 375.25 kg/m^3
New water cement ratio = 139.87/375.25 = 0.37
20% Flyers of cement is content = 75.05kg/m^3
cement=375.25-75.05=300.2kg/m^3
2% of superplasticizer of cementitious content=(2/100)*375.25=7.505kg/m^3
proportioning of volume of coarse and fine aggregate:
from Table 3 IS 10262 2009, for 0.5 water cement ratio, volume of coarse aggregate = 0.6
As per IS 10262-2009 for water cement ratio 0.37 volume of coarse aggregate =0.626
Since the concrete is pumpable volume of coarse aggregate is reduced by 10%
Volume of coarse aggregate = 0.626*0.9= 0.56
Volume of fine aggregate= 1 - 0.56=0.44
mix calculation:
a. Volume of concrete=1m^3
b.Volume of cement= (mass of cement/specific gravity of fly ash)*(1/1000)=(300.2/3.15)*(1/1000)=0.095m^3
c.volume of flyash= (mass of flyash/ specific gravity of flyash)*(1/1000)=(75.05/2.2)*(1/1000)=0.034m^3
d.volume of water =(mass of water/specififc gravity of water)*(1/1000)=(139.87/1)*(1/1000)=0.139m^3
e.super plasticizer is upto 2% of mass of total cementitious content=(7.505/1.15)*(1/1000)=0.006m^3
f.volume of aggregate=a-(b+c+d+e)=1-(0.095+0.034+0.139+0.006)=0.726m^3
g.mass of coarse aggregate=f*volume of coarse aggregate*specific gravity of coarse aggregate=0.726*0.56*2.73*1000=1110kg
h.mass of fine aggregate=f*volume of fine aggregate*specific gravity of fine aggregate=0.726*0.44*2.61=834kg
mix proportioning:
cement =300.2kg/m^3
flyash=75.05kg/m^3
fine aggregate=834kg/m^3
coarse aggregate=1110kg/m^3
w/c =0.37
admixture=7.505kg/m^3.
2.
concrete mix design for m50 without flyash
data required :
Grade designation: m 35 with 10% of flyash
Type of cement: opc 43 grade confirming to IS 8112
Maximum nominal size of aggregate column 20 mm
exposure type: extreme reinforced
Minimum cement content column 360 kg per m^3
Walkability: 100 mm slump
Method of concrete placing: pumping
Type of aggregate: crashed angular
Maximum cement content call 450 kg per metre cube
Chemical admixture: superplasticizer
Sir gravity of cement: 3.15
Specific gravity of flyash: 2.2
specific gravity of fine aggregate column 2.61
specific gravity of coarse aggregate column 2.73
Course and fine aggregate: grade 1
target strength:
f'ck = fck+1.65s
s=5 from table 1 of IS 10262 2009
f'ck = 50+(1.65*5)=58.25N/mm^2
selection of water cement ratio:
From Table 5 IS:456-2000 for severe exposure condition maximum water cement ratio is 0.40
Adopt water cement ratio = 0.33
selection of water content:
Maximum water content = 186 liters from table 2, 10262- 2009
For 75mm slump, water content = 186 + (6/100)*186) ~ 197
super plasticiser reduces 29% of water content
Hence new water content = (71/100)*197 = 139.87
calculating cement content:
Water/cement = 0.33
cementitious content =139.87/0.33=424>360kg/m^3
Thefore cementitions content =424kg/m^3
2.5% of superplasticizer of cementitious content=(2.5/100)*424=10.6kg/m^3
proportioning of volume of coarse and fine aggregate:
from Table 3 IS 10262 2009, for 0.5 water cement ratio, volume of coarse aggregate = 0.6
As per IS 10262-2009 for water cement ratio 0.33 volume of coarse aggregate =0.636
Since the concrete is pumpable volume of coarse aggregate is reduced by 10%
Volume of coarse aggregate = 0.636*0.91= 0.578
Volume of fine aggregate= 1 - 0.578=0.421
mix calculation:
a. Volume of concrete=1m^3
b.Volume of cement= (mass of cement/specific gravity of fly ash)*(1/1000)=(424/3.15)*(1/1000)=0.134m^3
c.volume of water =(mass of water/specififc gravity of water)*(1/1000)=(139.87/1)*(1/1000)=0.139m^3
d.super plasticizer is upto 2% of mass of total cementitious content=(10.6/1.15)*(1/1000)=0.0092m^3
e.volume of aggregate=a-(b+c+d)=1-(0.134+0.139+0.0092)=0.717m^3
f.mass of coarse aggregate=f*volume of coarse aggregate*specific gravity of coarse aggregate=0.717*0.578*2.73*1000=1131kg
g.mass of fine aggregate=f*volume of fine aggregate*specific gravity of fine aggregate=0.717*0.421*2.61=787kg
mix proportioning:
cement =424kg/m^3
fine aggregate=787kg/m^3
coarse aggregate=1131kg/m^3
w/c =0.33
admixture=10.6kg/m^3.