Project on Concrete Mix Design for various grades of Concrete
Mix design for m-35 with fly ash
Data assume
Grade of concrete = 35
Type of slume = 50 mm
Nominal aggregate size = 20 mm
Expose condition = severe
Chemical admixture = super plastizer
Step 1:- target mix strength
Fc'k = fck + 1.65 s
= 35+ 1.65*5 = 43.25 n/mm2
Step 2 :-selection of w/c ratio
= 0.4 w/c
Water content :- 186 lit.
Super plastizer chemical used so amount of water will redused
186*0.75= 140 litre
Step 3:- water content
W/c= 0.4 c= 350 kg/m3
Step 4. :- fly ash added in concrete
Cement content 350*1.10= 385 kg/m3
Water content = 140 kg/m3
W/c ratio. = 140/385 =0.364
Fly ash 30% of material = 385*0.3= 115 kg/m3
Cement = 385-115 = 270 kg/m3
Saving cement = 350-270= 80 kg/m3
Fly ash = 385-270= 115 kg /m3
5 ) for pumpable concrete volume will be reduse
Volume of C.A. :- 0.62*0.9= 0.56
Volume of F.A. :- 1-0.56= 0.44
6). Mass of concrete = 1m3
Volume of cement :-. (Mass of concrete / sp. Gravity of cement)*(1/1000)
(270/3.15)*(1/1000). = 0.086 m3
Volume of water :- (Mass of water / sp. Gravity of water )*(1/1000)
(140/1000) = 0.140 m3
Volume of fly ash :- (Mass of fly ash / sp. Gravity of fly ash)*(1/1000)=
(115/2 .3)*(1/1000) = 0.005 m3
Chemical admixture :- (Mass of chemical / sp. Gravity of chemical)*(1/1000)
(7/1.145)*(1/1000)
= 0.0007 m3
Volume of F.A.= 1-(0.007+0.56+0.086+0.140)
0.762
Mass of c.a.:-. 0.762*0.44*2.74*1000= 918.66 kg/m3
Cement :- 270 kg/m3, water :- 140 kg/m3 , F.A. :-. 918.66 kg/m3, fly ash :- 115 kg/m3 , C.A. :- 1169 kg/m3 , wc ratio :- 0.364
Mix grade. 1:3.4:4.32
2 )mix design for m 50 with out fly ash
- 1 ) target min strength
Fc'k = fck + 1.65 s
= 50 + 1.65*5 = 58.25 n/mm2
Step 2 :-selection of w/c ratio
= 0.4 w/c
Water content :- 186 lit.
Super plastizer chemical used so amount of water will redused
186* 0.75= 140 litre
Slump valvue = 75 mm so add 3% water amount. 140*1.3= 144.2 litre
Step 3:- water content
W/c= 0.4 c= 360.5 kg/m3
Step 4 for pumpable concrete volume will be reduse
Volume of C.A. :- 0.62*0.9= 0.56
Volume of F.A. :- 1-0.56= 0.44
Step 5 . Mass of concrete = 1m3
Volume of cement :-. (Mass of concrete / sp. Gravity of cement)*(1/1000)
(360.5/3.15)*(1/1000). = 0.114m3
Volume of water :- (Mass of water / sp. Gravity of water )*(1/1000)
(144.2/1000) = 0.1442 m3
Chemical admixture :- (Mass of chemical / sp. Gravity of chemical)*(1/1000)
(7/1.145)*(1/1000)
= 0.0007 m3
Volume of F.A.= 1-(0.007+0.1442+0.144)
0.7048
Mass of c.a.:-. 0.7048*0.56*2.74*1000= 1081.44kg/m3
Mass of f.a :- 0.7048*0.44*2.74*1000=849.70 kg/m3
Cement :- 360.5 kg/m3, water :- 144.2 kg/m3 , F.A. :-. 849.70g/m3, , C.A. :- 1081.44 kg/m3 ,
Mix grade. 1:1.74: 2.223