Project on Concrete Mix Design for various grades of Concrete
aim:mix design for M 53 grade concrete with fly ash
step:1
stipulations for proportioning
grade designation:M35
type of cement:opc 43 grade conforming to IS 8112
type of mineral admixture:fly ash conforming to IS 3812
maximum nominal size of aggregates:20mm
minimum cement content:320kg/m^3
maximumwater-cement ratio:0.45
workability:100mm slump value of pumpable concrete
exposure condition:severe
method of concrete placing:pumping
degree of supervision:good
type of aggregate:crushed angular aggregate
maximum cement content:450kg/m^3
chemical admixture type:superplaticizer
step:2
test data for materials
cement used:opc 43 grade confirming to IS 8112
specific gravity of cement:3.15
fly ash:conforming to IS 3812 part 1
specific gravity of flyash:2.2
chemical admixture:superplaticizer conforming to IS 9103
specific gravity of:
coarse aggregate:2.47
fine aggregate:2.47
water absorption:
coarse aggregate:0.5%
fine aggregate:1%
free surface moisture
coarse aggregate:nil
fine aggregate:nil
seive analysis
coarse aggregates:
IS analysis of % of
seive size coarse aggregate differnt remarks
(mm) fraction fraction
l ll l ll combined conforming
20 100 100 60 40 100 to
10 0 71.2 0 28.5 28.5 table 2
4.74 9.4 3.7 3.7 of
2.36 0 IS 383
fine aggregate:conformin to
gradin zone 1 of table 4 IS 383
step:3
target mean strength of mix proportioning
target mean strength fck=fck+1.65
=35+1.65*5
=43.25n/m m^2
fck-characteristic compressive strength
s-standard deviation
sytep-4
selection of water-cement ratio
maximum water cement-cement ratio=0.45
on experience water-cement ratio=0.4
0.4<0.45
step:5
maximum water content for 20mm
aggregate=186 litres(table 2 0f IS 1026:2009)for 25mm to 50mm slump range
for 100mm slump=186+(6/100)*186
=197 litres
as superplaticizer is used,the water content is reduced upto 30%
based on trials water content reduction of 29% is achieved with plasticizer
hence arrived water content=197*0.71=140 litres
step:6
calculation of cement content
water- cement ratio=0.4
cementatious materials ( cement+flyash)=140/0.4=350 k g/m^3
in table 5 of IS 456:2000,the cement content foe
severe exposure =320 k g/m^3
350 k g/m^3 >320 k g/m^3
to poroportion the mix containing flyash the flowing steps are suggested
in this increase of 10% cementatious material content is considered.
cementatious material content=350*1.1=385k g/m^3
water content =140k g/m^3
flyash at 30% total cementatious
material content=35-30%=115k g/m^3
cement(opc)=385-115=270k g/m^3
saving of cement while using flyash=
350-270=80k g/m^3
fly ash being utilized=115k g/m^3
step:7
volume of coarse aggregate and fine aggregate content
frome table 3 of IS 1026:2009,volume of coarse
aggregate corrsponding to 20mm size aggregate
and fine aggregate fpoe wqater-cement ratio=0.6
in present case the water-cement ratio is 0.4
as the water-cement ratio is lowered by 0.1,the proportion of volume oof coarse aggregate is increased by 0.02
for pumpable concrete,these are reduced by 10%
volume of coarse aggregate =o.64*0.9=0.576
volume of fine aggregate =1-0.576=0.424
step:8
mix calculations
mix calculation per unit volume of concrete
volume of concrete =1m^3
volume of cement =(mass of cement/specific gravity of cement)*1/1000
=(270/3.15)*1/1000
=0.086m^3
volume of flyash =(mass of cement/specific gravity of flyash)*1/1000
=0.052m^3
volume of water =(mass of water /specific gravity of flyash)*1/1000
=(140/1)*1/1000=0.140m^3
volume of chemical admixture=(mass of admixture / specific gravity of admixture)*1/1000
=(7.6/1.14)*1/1000=0.006m^3
volume of aggregate (fine and coarse)=a-(b+c+d+e)
=1-(0.086+0.052+0.140+0.006)=0.716m^3
mass of coarse aggregate =f*volume of coarse aggregate *specific gravity of fine aggregate *1000
=0.716*0.576*2.74*1000=1130k g/m^3
mass of fine aggregate=f*volume of fine aggregate*specific gravity of fine aggregate*1000
= 0.716*0.424*2.74*1000=831k g/m^3
step:9
cement=270k g/m^3
fly ash=115k g/m^3
water=140k g/m^3
fine aggregate=831k /m^3
coarse aggregate=1130k g/m^3
chemical admixture=7k g/m^3
water-cement ratio=0.364
mix ratio 1:2.15:2.94
result:the mix design for m35 grade of concrete with flyash is 1:2.15:2.94
design of m 50 grade concrete
aim:mix design of m50 grade concrete
step:1
stipulation for proportioning
grade designation:M50
type of cement:opc grade 43 conforming to IS 8112
maximum nominal sizeof aggregate:20mm
minmum cement content:320k g/m^3
maximum water-cement ratio:0.45(table 5 IS 456-2000, based onexposure condition)
workability:100mm,slum value of pumpable concrete
exposure condition:severe ,for reinforced concrete
method of concrete placing:pumping
degree of supervision:good
type of aggregate :crushed angular aggregate
maximum cement content:450 kg/m^3
chemical damixture type:superplaticizer
step:2
test data for materials
cement used:opc 43 grade confirming to IS 8112
specific gravity of cement:3.15
chemical admixture:superplaticizer conforming to IS 9103
specific gravity of:
coarse aggregate:2.74
fine aggregate:2.74
water absorption:
coarse aggregate:0.5%
fine aggregate:1%
step:3
target mean strength
fck=fck+1.65s
=50+1.65
=58.25 n/m m^2
step:4
from table:5 of IS 456-2000
severe condition is considered
maximum water-cement ratio=0.45
based on experience water-cement ratio=0.4
step:5
maximum water content for 20mm
aggreate =186 litres for 25mm to 50mm slump range
for 100mm slump =196+(6/100)*186
=197 liters
as superplaticizer is used the water content is reduced upto 30%
based on trials water content reduction of 29% is achieved with plasticizer
hence arrived water content =197*0.71=140 liters
step:6
calculation of cement content
water-cement ratio=0.4
cement content =140/0.4=350k g/m^3
in table 5 of IS 456-2000
the cement content for severe exposure=320k g/m^3
350k g/m^3 >320k g/m^3
step:7
volume of coarse aggregate and fine aggregate content
table 3 of IS 1026:2009,volume of coarse aggregate coresponding to 20mm size
aggregate and fine aggregate for watewr-cement ratio=0.6
present case the water=cement ratio is 0.4
therefore the volume of coarse aggregate needs to be increased to decreased the fine aggregate content
the corrected value of coarse aggregate for the water- cement ratio=0.64
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
unit volume of concrete
volume of concrete =1m^3
volume of cement=(mass of cement/specific gravity of cement)*1/1000
=(350/3.15)*1/1000
=0.11m^3
volume of water=(mass of water/specific gravity of water)*1/1000
=(140/1)*1/1000
=0.140 m^3
volume chemical admixture=(mass of admixture/specific gravity of admixture)*1/1000
=(7.6/1.145)*1/1000=0743 m^3
volume aggregate =a-(b+c+d)
=1-(0.111+0.140+0.006)=0.743 m^3
mass of coarse aggregate=e* volume of coarse aggregate*specific gravity of coarse aggregate*1000
=0.743*0.576*2.47*1000=1173k g/m^3
mass of fine aggregate =e* volume of fine aggregate *specific gravity of fine aggregate*1000
=0.743*0.424*2.47*1000=863 k g/m^3
step:9
mix proportion
cement=350k g/m^3
water=140 kg/m^3
fine aggreagte=863k g/m^3
coarse aggregate=1173k g/m^3
chemical admixture=7k g/m^3
water cement ratio=0.4
mix ratio=1:2.46:3.35