Project on Concrete Mix Design for various grades of Concrete
Calculate the Concrete Mix Design for M35 grade concrete with fly ash & M50 grade concrete without Fly ash
MIX DESIGN FOR M35 GRADE CONCRETE WITH FLY ASH
Aim: Mix design for M35 grade concrete with fly ash
procedure:
STEP:1
Stipulations for proportioning
a. Grade designation : M35
b. Type of cement : OPC 43 grade conforming to is 8112
c. Type of mineral admixute : fly ash confirming to is 3812 (part 1)
d. Maximum naminal size of aggregate :20mm
e. Minimum cement content : 320kg/m³ (Table :5is 456-2000, based on exposure condition )
f. Maximum water-cement ratio : 0.45 (Table : 5is 456-2000, based on exposure condition )
g. Workability : 100mm slump value of pump able concrete
h. Exposure condition: severe ( for reinforced concrete )
i. Method of concrete placing: pumping
j. Degree of supervision: Good
k. Type of agggregate : Crushed angular aggregate
l. Maximum cement content : 450 kg/m³.
m. Chemical admixure type: Superplasticizer.
Step : 2
Test data for materials
a. Cement used : OPC 43 grade confirming tois 8112
b. Specific gravity of cement : 3.15
c. Fly ash : Confirming to is 3812 part 1
d. Specific gravity of flyash: 22
e. Chemical admixure : Superplasticizer confirming to is 9103
f. Specific gravity of : Coarse aggregate : 2.74
Fine aggregate : 2.2
g. Water absorption : Coarse aggregate : 0.5%
Fine aggregate : 1%
h. Free surface moisture : Coarse aggregate : Nil
Fine aggregate : Nil
i. Seive analysis coarse aggregate:
IS seive size analysis of coarse aggregate % of different fraction Combined confirming to Remarks
(mm) fraction to table 2 of is 383
I II III
20 100 100 60 40 10
10 0 712 28.5
4.75 9.4 3.7
2.36 0
Fne aggregate: confirming to grading zone 1 of table 4 is 383.
step: 3
to find target mean strenght for mix proportioning
Target mean strenght f'ck = f'ck +1.65s
=35+1.65*5=43.25N/m m2
fck-Characteristic compressive strenght
s-Standard deviation
step: 4
selection of water-cement ratio
Maximum water-cement ratio= 0.45(for severe condition , from table 5 to is 456-2000)
on experiance water- cement ratio = 0.4
0.4 < 0.45 Hence ok.
step: 5
calculatio of water content
Maximum water content for 20mm aggregate = 186 liters ( table 2 of is 1026:2009) for 25mm to 500mm slump rangre
For 100mm slump,=186+(6/100)*186=197liters
As superplasticizer is used, the water content is reduced up to 30%
Based on trials water content reduction of 29% is achieved with plasticizer
Hence arrived water content = 197*0.71=140liters
step: 6
calculation of cement content
Water-cement ratio=0.4
cementatious material ( cement + flyash ) = 140/0.4=350kg/m³
In table 5 of is 456-2000, the cement content for severe exposure= 320kg/m³
350kg/m³>320kg/m³
Hence ok.
To proportionthe mix containing flyash the following steps are suggested:
a. The peercentage of flyash need to be decided based on project requirement and quality of materials.
b. In some cases increase in cementatious materials can be warrned. increase in cementatious material content and its
percentage may be based on experiance and trial
in this increase of 10% cementatious material content is considered.
Cementatious materail content = 350*1.1=385kg/m³
Water content = 140kg/m³
So, water -cement ratio= 140/385=0.364
fly ash at 30% total cementatious material coontent = 35-30%=115kg/m³
cement (opc)=385-115= 270kg/m³
saving of cement while using flyash= 350-270 = 80kg/m³
Fly ash bein utilized = 115kg/m³
step: 7
proportion of volume of coarse aggregate and fine aggregate content
From table 3 of is 1026:2009, volume of coarse aggregate correspondig to 20mm size aggregate and fine aggregate
(zone1) for water-cement ratio=0.6
In present case the water - cement ratio is 0.4
Therefore the volume of coarse aggregate needs to be increased to decrease the fine aggregate content.
As the water-cement ratio is lowered by 0.1, the proportion of volume of coarse aggregate is increased by 0.02 (at the rate
of +/-0.01for every +/-0.05 change in water- cement ratio)
Hence the corrected value of coarse aggregate for the water- cement ratio=0.64
(If coarse aggregate is not of angular type, then also the volume of coarse aggregate may be required to be
increased suitably, based on experience)
For pumpable concrete, these are reduced by 10%
volume of coarse aggregate= 0.64*0.9=0.576
volume of fine aggregate = 1-0.576=0.424
step: 8
Mix calculation per unit volume of concrete:
a. volume of concrete=1m^3.
b. volume of cement=(mass of cement/specific gravity of cement) *1/1000=(270/3.15)*1/1000=0.086 m³
c. volume of flyash=(mass of flyash/specific gravity of flyash)*1/1000=(115/2.2)*1/1000=0.052 m³
d. volume of water=(mass of water/specific gravity of water)*1/1000=(140/1)*1/1000=0.140 m³
e. voume of chemical admixure = (mass of admixure/specific gravity of admixure)*1/1000=(7.6/1.14)*1/1000=0.006 m³
f. mass of coarse aggregate= f*volume of coarse aggregare *specific gravity of coarse aggregate *1000
=0.716*0.576*2.74*1000=1130kg/m³
h. mass of fine aggregate = f*volume of fine aggregate *specific gravity of fine aggregate*1000
=0.716*0.424*2.74*1000=831kg/m³
step: 9
Mix proportion
Cement = 270kg/m³
Fly ash =115kg/m³
Water = 140kg/m³
Fine aggregate =831kg/m³
Coarse aggregate = 1130kg/m³
Chemical admixure = 7kg/m³
Water- cement ratio= 0.364
Mix ratio 1:2.15:2.94
step : 10
The slump shall be measured and the water content and dosage of admixyure shall be adjusted for acheiving the required
slump on trial. The mix proportion shall be reworked for the actual water content and checked for durability requirements.
step: 11
Two or more trials having variation of 10% of water-cement ratio in clause10(step10) shall be carried out and a graph
between tree water-cement ratios and corresponding strenghts shall be plotted to work out he mix proportions for the
given target strenght for feild trials. However durability shall be met.
Result : The mix design for M35 grade of concrete with flyash is 1:2.15:2.94
MIX DESIGN OF M50 GRADE CONCRETE
Aim : Mix design of m50 grade concrete
procedure:
step:1
stipulation for proportioning
a. Grade designation : M50
b. Type of cement: opc grade 43 confirming to is 8112
c. maximum naminal size of aggregate: 20mm
d. minimum cement content: 320kg/m³
e. maximum water-content ratio: 0.45(table:is 456-2000, based on exposure condition)
f. Warkablity:100mm, slump value of pumpable concrete
g. Exposure condition: severe (for reinforced concrete)
h. Method of concrete placing: pumping
i. Degree of supervision : Good
j. Type of aggregate: Crushed angular aggregate
k. Maximum cement content : 450kg/m³
l. chemical admixure type : superplasticizer
step: 2
test data for materials
a. Cement used : OPC 43 grade confirming to is 8112
b. specific gravity of cement : 3.15
c. Chemical admixure: Superplasticizer conforming to is 9103
d. specific gravity of :
coarse aggregate: 2.74
Fine aggregate :2.74
e. Water absorption:
coarse aggregate: 0.5%
Fine aggregate :1%
f. Free surface moisture:
Coarse aggregate:Nil
Fine aggregate: Nil
Seive analysis coarse aggregate:
IS seive size analysis of coarse aggregate % of different fraction Combined confirming to Remarks
(mm) fraction to table 2 of is 383
I II III
20 100 100 60 40 10
10 0 712 28.5
4.75 9.4 3.7
2.36 0
Fine aggregate : Conforming to grading Zone 1 of table 4 is 383.
step: 3
To find target mean strenght for proportioning
Target mean strenght, f'ck = fck+1.65s
=50+1.6585=58.25 N/M*M²
fck=characterestic strenght
s=standard deviation
step: 4
selection of water-cement ratio
From table : 5 of is 456-2000, by exposure condition
Here severe condition is considered, Maximum water-cement ratio= 0.45
Based on experiance water- cement ratio = 0.4
0.4 < 0.45 Hence ok.
step: 5
Selection of water content
Maximum water content for 20mm aggregate = 186 liters ( table 2 of is 1026:2009) for 25mm to 500mm slump rangre
For 100mm slump,=186+(6/100)*186=197liters
As superplasticizer is used, the water content is reduced up to 30%
Based on trials water content reduction of 29% is achieved with plasticizer
Hence arrived water content = 197*0.71=140liters
step: 6
calculation of cement content
Water-cement ratio=0.4
cementatious material ( cement + flyash ) = 140/0.4=350k g/m³
In table 5 of is 456-2000, the cement content for severe exposure= 320k g/m³
350k g/m3>320k g/m³
Hence ok.
step: 7
proportion of volume of coarse aggregate and fine aggregate content
From table 3 of is 1026:2009, volume of coarse aggregate correspondig to 20mm size aggregate and fine aggregate
(zone1) for water-cement ratio=0.6
In present case the water - cement ratio is 0.4
Therefore the volume of coarse aggregate needs to be increased to decrease the fine aggregate content.
As the water-cement ratio is lowered by 0.1, the proportion of volume of coarse aggregate is increased by 0.02 (at the rate
of +/-0.01for every +/-0.05 change in water- cement ratio)
Hence the corrected value of coarse aggregate for the water- cement ratio=0.64
(If coarse aggregate is not of angular type, then also the volume of coarse aggregate may be required to be
increased suitably, based on experience)
For pumpable concrete, these are reduced by 10%
volume of coarse aggregate= 0.64*0.9=0.576
volume of fine aggregate = 1-0.576=0.424
step: 8
Mix calculation
For unit volume of concrete
a. volume of concrete=1m3
b. volume of cement= (mass of cement /specific gravity of cement )*1/1000=(350/3.15)*1/1000=0.111m³
c. volume of water= (mass of water / specific gravity of water)*1/1000=(140/1)*1/1000=0.006m³
d. volume of chemical admixures= (mass of admixure/ specific gravity of admixures)*1/1000
=(7.6/1.145)*1/1000=0.006m³
e. volume of aggregate (fine and coarse )=a-(b+c+d)=1-(0.111+0.140+0.006)=0.743m³
f. mass of coarse aggregate =ex volume of coarse aggregate x specific gravity of coarse aggregate x 1000
=0.743*0.576*2.74*1000=1173kg/m³
g. mass of fine aggregate= e*volume of fine aggregate*specific gravity of fine aggregate * 1000
=0.743*0.424*1000=863kg/m³
step: 9
Mix proportion
Cement = 350kg/m³
Water = 140kg/m³
Fine aggregate =863kg/m³
Coarse aggregate = 1173kg/m³
Chemical admixure = 7kg/m³
Water- cement ratio= 0.4
Mix ratio=1:2.46:3.35
step : 10
The slump shall be measured and the water content and dosage of admixyure shall be adjusted for acheiving the required
slump on trial. The mix proportion shall be reworked for the actual water content and checked for durability requirements.
step: 11
Two or more trials having variation of 10% of water-cement ratio in clause10(step10) shall be carried out and a graph
between tree water-cement ratios and corresponding strenghts shall be plotted to work out he mix proportions for the
given target strenght for feild trials. However durability shall be met.
Result : The mix ratio for M50 grade concrete is 1:2.46:3.35
Table used are:
1.Table :8 of is 10262
Grade Standard deviation (s) N/mm^2
M10 3.5
M15 3.5
M20 4
M25 4
M30 5
M35 5
M40 5
M45 5
M50 5
+1N/mm^2where there is deviation, when not periodically checked for workability and strength
2.Table :5 of is 456-2000
Based on exposure condition
plain cincrete reinforced concrete
SI.NO EXPOSURE min cement content max water-cement min grade of min cement max free w/c min grade
(kg/m³) ratio(kg/m³) concrete(kg/m³) c0ntent(kg/m³) ratio of concrete
1. Mild 220 0.6 - 300 0.55 M20
2. Moderate 240 0.6 M15 300 0.5 M25
3. Severe 250 0.5 M20 320 0.45 M30
4. Very severe 260 0.45 M20 340 0.45 M35
5. Extreme 280 0.4 M25 360 0.4 M40
3. Table : 2of is 10262:2009
SI.NO Nominal maximum size of aggregate (mm) Maximum water content (kg)
1. 10 280
2. 20 186
3. 40 165
4. Table :3 is 1026:2009
volume of coarse aggregate per unit volume of total aggregate for dofferent zones of fine aggregate
SI.NO NOMINAL SIZE ZONE 4 ZONE 3 ZONE 2 ZONE 1
OF AGGREGATE
1. 10 0.5 0.48 0.46 0.44
2. 20 0.66 0.64 0.62 0.6
3. 40 0.75 0.73 0.71 0.69