Project on Concrete Mix Design for various grades of Concrete
1. Grade of concrete - M35
cement - OPC 53
Type of admixture -Flyash
Maximum nominal size of aggregate-20 mm
Minimum cement content-340kg/m3
Maximum ce,ent content-450 kg/m3
Partial replacement of cement by flyash -30%
W/C ratio - 0.45
Workability- 100 mm
Chemical admixture - PCS type
test data
Specific gravity of cement- 3.15
Specific gravity of fly ash - 2.9
Chemical admixture - 0.6%
Specific gravity of CA-2.74
Specific gravity of FA-2.74
Specific gravity of admixture PCE - 1.12
Water absorption of CA-0.5%
Water absorption of FA-1%
Sieve analysis FA- Zone 2
Target mean strength for mix proportion ft=fck+1.65S
=35+(1.65*5)
ft= 43.25 N/mm2
adopted water/cement ratio from IS-456 = 0.45
Maximum Watercontent = 186 ltr from IS-10262
Above water-content is for 25 to 50mm slump but the slump we require is 100mm. hence we need to increase the water
content to get the required slump for good workability. Clause 4.2 of IS1026 suggests an increase of 3% of water content
from its original value for every increase of 25mm. Here we have a 50mm increase in the water content hence we have to
increase the water content by 6 %.
Hence Watercontent for 100 mm slump= 186+6%
=197.16 ltr
Since superplasticizers are used water content can be reduced to get good strength of concrete. The percentage of reduction
of water depends on the type of superplasticizers used in the concrete.
% reduction in water content = 20%
=197.16-20%
=157 ltrs
Adopted water content = 160 ltrs
Calculation of cement and Fly ash content
W/C ratio=0.45
Total cement content (cement +flyash)= Watercontent/w/c ratio
= 160/0.45
= 355.55 kg
Increase by 1.1 % = 355.55+1.1%= 391.6 kg > 340 kg hence ok
Flyash content requirement =391.6* 30%=118 kg
Cement content= 391.6-118=274.12 kg
Superplasticizers = 391.6*0.6%= 2.35 kg
CA ratio=0.62 as per IS-10262 table 3 for w/c ratio-0.5
CA ratio =0.63 adding 0.01 for decrease of 0.05 in w/c ratio
FA ratio = 0.37 (1-0.63)
A) Volume of concrete=1 m3
B)Volume of cement =mass/sg*1000=275/(3.15*1000)=0.087 m3
C)Volume of flyash = 118/(2.5*1000)=0.041 m3
D)Volume of water =160/(1*1000)=0.15 m3
E)Volume of super plasticizer =2.35/(1.121*1000)=0.002 m3
F)Total aggregates requirement =A-(B+C+D+E)
=1-(0.087+0.041+0.16+0.002)
=0.71 m3
CA = F *CA ratio*Sg*1000=0.71*0.63*2.74*1000=1225.6 KG
FA= F*FAratio *sg*1000= 0.71*0.37*2.74*1000= 719.8 kg
Materials
Cement=275 kg
Flyash= 118 kg
Water = 160 ltr
FA= 720 KG
CA=1226 KG
SUPER PLASTICIZER PCE =2 LTR
Mix ratio = cement: flyash:fa:ca:water=1:0.4:2.6:4.46:0.58.
2. M 50 GRADE WITHOUT FLYASH
cement - OPC 53
Maximum nominal size of aggregate-20 mm
Minimum cement content-340kg/m3
Maximum cement content-450 kg/m3
W/C ratio - 0.45
Workability- 50 mm
Wxposure condition =severe
Chemical admixture - PCS type
test data
Specific gravity of cement- 3.15
Chemical admixture - 2% by mass po
Specific gravity of CA-2.74
Specific gravity of FA-2.74
Specific gravity of admixture - 1.145
Water absorption of CA-0.5%
Water absorption of FA-1%
Sieve analysis FA- Zone 2
Target mean strength for mix proportion ft=fck+1.65S
=50+(1.65*5)
ft= 58.25 N/mm2
adopted water/cement ratio from IS-456 = 0.45
Maximum Watercontent = 186 ltr from IS-10262
adopted water content=186 ltr
Calculation of cement and Fly ash content
W/C ratio=0.45
Total cement content = Watercontent/w/c ratio
= 186/0.45
= 413.33 kg > 320 kg hence ok
CA ratio=0.62 as per IS-10262 table 3 for w/c ratio-0.5
CA ratio =0.63 adding 0.01 for decrease of 0.05 in w/c ratio
FA ratio = 0.37 (1-0.63)
A) Volume of concrete=1 m3
B)Volume of cement =mass/sg*1000=413/(3.15*1000)=0.13 m3
C)Volume of water =186/(1*1000)=0.186 m3
E)Volume of ADMIXTURE =2.35/(1.121*1000)=0.002 m3
F)Total aggregates requirement =A-(B+C+D+E)
=1-(0.087+0.041+0.16+0.002)
=0.77 m3
CA = F *CA ratio*Sg*1000=0.77*0.63*2.74*1000=1022 KG
FA= F*FA ratio *sg*1000= 0.77*0.37*2.74*1000= 835 kg
Materials
Cement=413 kg
Water = 200 ltr
FA= 835KG
CA=1022 KG
Admixture =1.65 kg
ratio= 1:2.35:2.86 cement:fa:ca