Project on Concrete Mix Design for various grades of Concrete
1. The Concrete Mix Design for M35 grade concrete with fly ash :
Aim & Introduction: To caculate the concrete mix design for M35 concrete with fly ash
Procedure for details in mix proportion of M35 grade concrete used in IS code :
I. Stipulation of proportioning :
- Grade designation : M35
- Type of cement : OPC M43 grade conforming to IS 8112
- Type of mineral admixture : Fly ash conforming to IS 3821 (part 1)
- Maximum nominal size of aggregate : 20mm
- Mminimum cemen content: 320Kg/m^3
- Maximum water cement ratio: 0.45 ( from table 5 of IS 456-2000 - Exposure condition)
- Worability : 100 mm ( slump value for pumbable concrete)
- Exposure condition: Severe ( for reinforced concrete)
- Method of concrete placing: pumbing
- Degree of supervision: Good
- Type of aggregate: crushed angular aggregate
- Maximum cement content: 450 kg/m^3
- Chemical admixture type: superplastizier
II. Test Data for Material:
- Cement used : OPC 43 grade of cement conforming to IS 8112
- Specific gravity of cement 3.15
- Fly ash conforming to IS 3812 (part 1)
- Specific gravity of fly ash: 2.2
- chemical admixture : superplastizier conforming to IS 9103
- specific gravity of coarse aggregate : 2.74, and fine aggregate : 2.74
- water absorbtion for Coarse aggregate : 0.51 %, and fine aggregate : 1.0 %
- fresh surface moisturefor coarse aggregate : nil , and fine aggregate : nil ,
- and coarse aggregate found as per Table:2 IS 283, fine aggregate : conforming fron grading zone1, zone2, zone3 of table 4 IS 383
III. Target strenght for mix proportion using to formula :
f'ck = fck+1.65 s
where,
f'ck: Target average compressive strenght at 28days
fck: Characterisitic compressive strenght at 28 days
s: Standard deviation
so from table 1 of IS 10262 : 2009 standard deviarion is clculate for M35 concrete : s= 5N/mm^2
therefore Target strenght : 35+1.65*5=43.25N/mm^2
VI. Selection of water/cement ratio:
from the table 5 of IS 456:2000 for severe exposurer maximum water/cement ratio=ratio is 0.40and aslothe water cement ratio the lesser the water cement ratio vlue is camsider for mix design
0.40 < 0.45, Hence ok
V. Selection of water concent:
From the table 2 of IS 10262:2009 maximum water content for 20mm aggregate: 186 Litre
( for 25mm to 50mm aslump range)
and for addition slump 3% make added for every 25mm slump for estimate water content for 100mm slump
= 186+6/100*186
=197 litre
As superplasticizer is used to water centent can be reduce up to 20% and above based on triale watr content reduction of 29% is achieverd with plasticizer
Hence we have clculate the arrived water concent
= 197*0.71=140 litre
As super plasticizer is used, the water content can be reduced up to 30%
Based on trials water content reduction of 29% is achieved with plasticizer.
Hence the arrived water content = 197*0.71 = 140 litre
VI. Calculation of cement content:
water cement ratio: 0.4
Cement content= 140 litre
Cementitious material(Cement+fly ash)content = 140/0.04= 350 kg/m^3
which from table 5 of IS 456 minimum cement content for 'severe' exposure condition = 320Kg/m^3
Now to proportion a mix containing fly ash the following steps are suggested:
- The percentage of l=fly as needs to be decided based on project requirement and quality of materials
- In some case increase in cementitious materrial can be waranted. Increase in cementitous material content and its percentage may be based on experience and trial (This example is with increase of 10% cementitious material content)
Cementitious material content = 350*1.10=385 Kg/m^3
Water content = 140 Kg/m^3
So, Water-cement ratio = 140/385 = 0.364
flly as @ 30% total cementitious material content = 385*30%=115 Kg/m^3
Cement (OPC) = 385-115=270 Kg/m^3
Saving of cement while using fly ash = 350-270=80 Kg/m^3 and
Fly ash being utilized = 115 Kg/m^3
VII. Proportion of valume of coarse aggregate content:
- which is calcuate from Table 3 of IS 10262: 2009, colume of coarse aggregate correspoding to 20 mm sie aggregate need to be icreased to decrease to fine aggregae content
- surface that water cement ratio is lower by 0.01 the proportion of volume of concrete is increased by 0.02 ( as the ratio of -/+ 0.01 for over +/- 0.05 change in water cementraio)
- so the corrected valume of coarse aggregate for the w/c ratio of 0.04 +0.02 and ,mainly we have to keep in mind that the coarse aggregate is agular type the calume of coarse aggregate we requiest to be increared based on angulars type then again the calime of coasre aggregate to incfeas suitably so this is how we ha ve clculate the callume of coarse aggregate and cimne aggregate using the table
- so wet pumbing concrete and valume are reduce by 10%
therefore, volume of coarse aggregate : 0.62*0.9=0.56
volume of fine aggregate content= 1-0.56=0.44
VIII. Mix calculation:
The mix calculation for unit volume of concrete shall be a follows
- Volume of concrete: 1m^3
- Volume of cement: Mass ofcement / surface gravity of cement*1/1000 , =270/3.15*1/1000 =0.086 m^3
- Volume of Fly ash = Msdd of fly ash/Specific gravity of fly ash* 1/1000 = 115/2.2*1/1000= 0.052 m^3
- Volume of water: Mass if water/surface gravity of water*1/1000, = 140/1*1/1000=0.140 m^3
- Volume of chemical admixture : Mass of admixture /surface gravity of admixture *1/1000, = 7.6/1.145*1/1000= 0.006 m^3
- Volume of total aggregate ( fine aggregate & coarse aggregate) = (a-(b+c+d)) = (1-(0.086+0.052+0.140+0.006)) =0.716m^3
- Mass of coarse aggregate = f*volume of Coarse aggregate *surface gravity of Fine aggregate *1000 ,= 0.716*0.56*2.74*1000=1098 Kg/m^3
- Mass of fine aggregate: f*volume of fine aggregate*surface gravity of fine aggregate * 1000 = 0.716*0.44*2.74*1000 = 863 Kg/m^3
IX. Mix proportion for trail number1:
Cement = 270 kg/m^3
Fly ash = 115 Kg/m^3
Water = 140 kg/m^3
Fine aggregate = 863 kg/m^3
Coarse aggregate = 1098 kg/m^3
Chemicl admixture = 7 kg/m^3
W/C ratio= 0.364
Trail mix ratio 1:2.24 :2.85
X. The slump shall be measured and the water conctent and dosage of admixture shall be adjusted for achieving the required slump on trial. The mix proportion shall be reworked for the actual water content and checked for durability requirements
XI. Two moe trials having variation of 10% of water-cement rattio in clause X shall be carried out and graph between three water-cement rations and corresponding strenghts shall be plotted to work ou the mix proportions or the given target strength for field trials. However, durability shall be met.
Result for mix proportion of M35 concrete with using Fly ash:
Cement = 270 kg/m^3
Fly ash = 115 Kg/m^3
Water = 140 kg/m^3
Fine aggregate = 863 kg/m^3
Coarse aggregate = 1098 kg/m^3
Chemicl admixture = 7 kg/m^3
W/C ratio= 0.364
Trail mix ratio 1:2.24 :2.85
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2. The Concrete Mix Design for M50 grade concrete without Fly ash:
Aim & Introduction: To caculate the concrete mix design for M50 concrete:
Procedure for details in mix proportion of M50 grade concrete used in IS code :
I. Stipulation of proportioning :
- Grade designation : M50
- Type of cement : OPC M43 grade conforming to IS 8112
- Maximum nominal size of aggregate : 20mm
- Mminimum cemen content: 320Kg/m^3
- Maximum water cement ratio: 0.45 ( from table 5 of IS 456-000 - Exposure condition)
- Worability : 100 mm ( slump value for pumbable concrete)
- Exposure condition: Severe ( for reinforced concrete)
- Method of concrete placing: pumbing
- Degree of supervision: Good
- Type of aggregate: crushed angular aggregate
- Chemical admixture type: superplastizier
II. Test Data for Material:
- Cement used : OPC 43 grade of cement conforming to IS 8112
- Specific gravity of cement 3.15
- chemical admixture : superplastizier conforming to IS 9103
- specific gravity of coarse aggregate : 2.74, and fine aggregate : 2.74
- water absorbtion for Coarse aggregate : 0.51 %, and fine aggregate : 1.0 %
- fresh surface moisturefor coarse aggregate : nil , and fine aggregate : nil ,and coarse aggregate found as per Table:2 IS 283, fine aggregate : conforming fron grading zone1, zone2, zone3 of table 4 IS 383
III. Target strenght for mix proportion using to formula :
f'ck = fck+1.65 s
where,
f'ck: Target average compressive strenght at 28days
fck: Characterisitic compressive strenght at 28 days
s: Standard deviation
so from table 1 of IS 10262 : 2009 standard deviarion is clculate for M50 concrete : s= 5N/mm^2
therefore Target strenght : 50+1.65*5=58.25 N/mm^2
VI. Selection of water/cement ratio:
from the table 5 of IS 456:2000 for severe exposurer maximum water/cement ratio=ratio is 0.40and aslothe water cement ratio the lesser the water cement ratio vlue is camsider for mix design
0.40 < 0.45, Hence ok
V. Selection of water concent:
From the table 2 of IS 10262:2009 maximum water content for 20mm aggregate: 186 Litre
( for 25mm to 50mm aslump range)
and for addition slump 3% make added for every 25mm slump for estimate water content for 100mm slump
= 186+6/100*186
=197 litre
As superplasticizer is used to water centent can be reduce up to 20% and above based on triale watr content reduction of 29% is achieverd with plasticizer
Hence we have clculate the arrived water concent
= 197*0.71=140 litre
VI. Calculation of cement content:
water cement ratio: 0.4
Cement content= 140 litre
=140/0.4=350Kg/m^3
350Kg/m^3 > 320Kg/m^3 ,Hence ok
which from table 5 of IS 456 minimum cement content for severe exposure condition = 320Kg/m^3
VII. Proportion of valume of coarse aggregate content:
- which is calcuate from Table 3 of IS 10262:colume of coarse aggregate correspoding to 2mm sie aggregate need to be icreased to decrease to fine aggregae content
- surface that water cement ratio is loqwer by 0.01 the proportion of volume of concrete is increased by 0.02 ( as the ratio of -/+ 0.01 for over +/- 0.05 change in water cementraio)
- so the corrected valume of coarse aggregate for the w/c ratio of 0.04 +0.02 and ,mainly we have to keep in mind that the coarse aggregate is agular type the calume of coarse aggregate we requiest to be increared based on angulars type then again the calime of coasre aggregate to incfeas suitably so this is how we ha ve clculate the callume of coarse aggregate and cimne aggregate using the table
- so wet pumbing concrete and valume are reduce by 10%
therefore, volume of coarse aggregate : 0.62*0.9=0.56
volume of fine aggregate content= 1-0.5=0.44
VIII. Mix calculation:
The mix calculation for unit volume of concrete shall be a follows
- Volume of concrete: 1m^3
- Volume of cement: Mass ofcement / surface gravity of cement*1/1000 , =350/3.15*1/1000 =0.111m^3
- Volume of water: Mass if water/surface gravity of water*1/1000, = 140/1*1/1000=0.140 m^3
- Volume of chemical admixture : Mass of admixture /surface gravity of admixture *1/1000, = 7.6/1.145*1/1000= 0.006 m^3
- Volume of total aggregate ( fine aggregate & coarse aggregate) = (a-(b+c+d)) = (1-(0.111+0.140+0.006)) =0.746m^3
- Mass of coarse aggregate = e*volume of Coarse aggregate *surface gravity of Fine aggregate *1000 ,= 0.74*0.56*2.74*1000=1140 Kg/m^3
- Mass of fine aggregate: e*volume of fine aggregate*surface gravity of fine aggregate * 1000 = 0.743*0.44*2.74*1000 = 896 Kg/m^3
IX. Mix proportion for trail number1:
Cement = 350 kg/m^3
Water = 140 kg/m^3
Fine aggregate= 896 kg/m^3
Coarse aggregate= 1140 kg/m^3
Chemicl admixture = 7 kg/m^3
W/C ratio= 0.4
Trail mix ratio 1:2.56:3.36
X. The slump shall be measured and the water conctent and dosage of admixture shall be adjusted for achieving the required slump on trial. The mix proportion shall be reworked for the actual water content and checked for durability requirements
XI. Two moe trials having variation of 10% of water-cement rattio in clause X shall be carried out and graph between three water-cement rations and corresponding strenghts shall be plotted to work ou the mix proportions or the given target strength for field trials. However, durability shall be met.
Result for mix proportion of M50 concrete without using Fly ash:
Cement = 350 kg/m^3
Water = 140 kg/m^3
Fine aggregate= 896 kg/m^3
Coarse aggregate= 1140 kg/m^3
Chemicl admixture = 7 kg/m^3
W/C ratio= 0.4
Trail mix ratio 1:2.56:3.36
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