Project on Concrete Mix Design for various grades of Concrete
Ans.MIX DESIGN M35 CONTAINING FLY ASH GRADE CONCRETE
1. STIPULATION FOR PROPORTIONING
Grade Designation = M35
Type of cement = OPC 43 Grade Confirming IS 8112
Maximum Nominal Size of agreegate =20mm
Minimum Cement Content =340kg/m^3 (for Very Severe Exposure Condition IS 456 :2000 Table 5)
Maximum water cement ratio=0.45
workability of concrete = 100mm Slump
Exposure Condition = Very Severe For RCC
Method of Concrete placing = Pumping
Degree of supervisison = Good
Type of Agreegate = Angular Agreegate
Maximum Cement Content =450 kg/m^3
Chemical admixture =Superplasticizer
TEST DATA FOR MATERIALS
Cement used = OPC 43 Grade
Specific gravity of cement =3.15
Fly Ash = Confirming IS 3812 part 1
Specific Gravity of Fly-Ash= 2.2
Chemical Admixture = Superplasticizer Confirming IS 9103
Specific gravity of Agreegates
1. Coarse Agreegate=2.74
2. Fine Agreegate =2.74
Water absorption:
1. Coarse agreegate =.5
2. Fine agreegate =1.0
Free Surface moisture
1. Coarse agreegate =NIL
2. Fine agreegate =NIL
TARGET MEAN STRENGTH
fck+1.65*s
(s= 5 standard deviation taken from table 1 IS 10262:2009)
35+1.65*5
F =43.25 N/mm^2
SELECTION OF WATER CEMENT RATIO
From Table 5 IS 456:2000
Maximum water cement Ratio =0.45
Based on Experience adopt water cement ratio= 0.40
0.40<0.45 hence OK
SELECTION WATER CONTENT
From table 2 IS 10262:2009
Maximum water content = 186 litre (for nominal size of agreegate 20mm) for 25 to 50 mm slump
Estimated water content =186+(6/100)*186
= 197 Litre
As we add superplastisizer in concrete water content can be reduced by 30%
Based on trials with superplastisizer water content reduction 29% achieved
than
=.71*197
=140 Litre
CALCULATION CEMENT AND FLY ASH CONTENT
Water cement ratio (Note 4.1 IS 10262:2009) =140/0.40
=350 kg/mm^2
350kg/m^3>340 kg/m^3 (Table 5 IS 456:2000) foe very Severe Exposure Condition
Hence OK
now to proporation a mix containing fly ash the following steps done
Increase 10 percent of cement cementious material content
than Cementious material Content - 1.1*350
= 385 kg/m^3
So the water cement ratio = 140/385
= .364
Fly ash taken 30 percent of total cement content
= .30*385
=115 kg/m^3
Cement = 385-115
=270 kg/m^3
Saving of cement while using Fly ash =350-270
= 80 kg/m^3
Flu ash used = 115 kg/m^3
PROPORTION OF VOLUME OF COARSE AGREEGATE AND FINE AGREEGATE CONTENT
From Table 3 IS 10262:2009
Volume of coarse agreegate corresponding to 20mm size agreegate and fine agreegate (Zone 1) for water cement ratio .5 =.60
In present case water cement ratio used is 0.40 so that volume of coarase agreegate is required to be increase to decrease the fine agreegate content. As the water cement ratio is lower by .10 then the volume of coarse agreegate is increased by .02 for -/+ 0.01 for every change in water cement ratio of .40=.62
For Pumpable concrete these values should be reduced by 10 percent
Therefore, Volume of Coarse agreegate = 0.62*.9
=.56
Volume of fine agreegate content= 1-0.56
= 0.44
MIX CALCULATION
mix calculation per unit volume of concrete shall be as follows
a)Volume of concrete = 1 m^3
b)
Volume of cement = (Mass of cement /Specific gravity of cement )*(1/1000)
= (270/3.15)*(1/1000)
= 0.086 m^3
c)
Volume of Fly ash= (Mass of fly ash/Specific gravity of fly ash)*(1/1000)
= (115/2.2)*(1/1000)
= 0.052 m^3
d).Volume of Water =(Mass of water/specific gravity of water)*(1/1000)
= (140/1)*(1/1000)
= 0.007
e).Volume of cement Admixture(superplasticizer)@ 2% by mass of cementitious Material = (7/1.145)*(1/1000)
= 0.006 m^3
f).Volume of all in agreegate = ( a-(b+c+d+e)
= (1-(0.086+0.052+0.140+0.006)
= 0.716
Mass of Coarse agreegate = f*volume of coarse agreegate*specific gravity of coarse agreegate*1000
= 0.716*0.56*2.74*1000
= 1098 kg
Mass of Fine agreegate = f*volume of coarse agreegate*specific gravity of coarse agreegate*1000
= 0.715*0.44*2.74*1000
= 863 kg
MIX PROPORTION FOR TRIAL NUMBER ONE For 1 cubic Meter
Cement =350 kg
water =140 kg
fine agreegate = 863 kg
coarse agreegate =1098 kg
Admixture =9.87 kg
Water cement ratio =0.40
MIX DESIGN M50 GRADE CONCRETE
1. STIPULATION FOR PROPORTIONING
Grade Designation = M50
Type of cement = OPC 43 Grade Confirming IS 8112
Maximum Nominal Size of agreegate =20mm
Minimum Cement Content =340kg/m^3 (for Very Severe Exposure Condition IS 456 :2000 Table 5)
Maximum water cement ratio=0.45
workability of concrete = 100mm Slump
Exposure Condition = Very Severe For RCC
Method of Concrete placing = Pumping
Degree of supervisison = Good
Type of Agreegate = Angular Agreegate
Maximum Cement Content =450 kg/m^3
Chemical admixture =Superplasticizer
TEST DATA FOR MATERIALS
Cement used = OPC 43 Grade
Specific gravity of cement =3.15
Chemical Admixture = Superplasticizer Confirming IS 9103
Specific gravity of Agreegates
1. Coarse Agreegate=2.74
2. Fine Agreegate =2.56
Water absorption:
1. Coarse agreegate =0.5
2. Fine agreegate =1.0
Free Surface moisture
1. Coarse agreegate =NIL
2. Fine agreegate =NIL
TARGET MEAN STRENGTH
fck+1.65*s
(s= 5 standard deviation taken from table 1 IS 10262:2009)
50+1.65*5
F =58.25 N/mm^2
SELECTION OF WATER-CEMENT RATIO
Based on experience assume water cement ratio=0.35
and by graph IS 10262:2019
SELECTION WATER CONTENT
From table 2 IS 10262:2009
Maximum water content = 186 litre (for nominal size of agreegate 20mm) for 25 to 50 mm slump
Estimated water content =186+(6/100)*186
= 197 Litre
As we are adding superplasticizer the water content should be reduced by 20-30%
Based on experimental studies 29% reduction of water content takes place
So that =0.71*197
= 140 litre
CALCULATION CEMENT
Water cement ratio (Note 4.1 IS 10262:2009) =140/.35
=400kg
400kg> 340 kg Hence ok
PROPORTION OF VOLUME OF COARSE AGREEGATE AND FINE AGREEGATE CONTENT
From Table 3 IS 10262:2009
Volume of coarse agreegate corresponding to 20mm size agreegate and fine agreegate (Zone 1) for water cement ratio .5 =.60
In present case water cement ratio used is 0.40 so that volume of coarase agreegate is required to be increase to decrease the fine agreegate content. As the water cement ratio is lower by .10 then the volume of coarse agreegate is increased by .02 for -/+ 0.01 for every change in water cement ratio of .35=.63
For pumpable concrete value should be reduced by 10%
=0.9*0.63
Therefore volume of coarse agreegate = 0.57
Volume of fine agreegate = 1-0.57
=0.43
MIX CALCULATION
mix calculation per unit volume of concrete shall be as follows
a)Volume of concrete = 1 m^3
b)
Volume of cement = (Mass of cement /Specific gravity of cement )*(1/1000)
= (400/3.15)*(1/1000)
= 0.126 m^3
d).Volume of Water =(Mass of water/specific gravity of water)*(1/1000)
= (140/1)*(1/1000)
= 0.140
e).Volume of cement Admixture(superplasticizer)@ 2% by mass of cementitious Material = (8/1.145)*(1/1000)
= 0.00698m^3
f).Volume of all in agreegate = ( a-(b+c+d+e)
= (1-(0.126+0.0+0.140+0.00698)
= 0.72702
Mass of Coarse agreegate = f*volume of coarse agreegate*specific gravity of coarse agreegate*1000
= 0.727*0.57*2.74*1000
= 1135.4 kg
Mass of Fine agreegate = f*volume of coarse agreegate*specific gravity of coarse agreegate*1000
= 0.727*0.43*2.74*1000
= 856.55 kg
MIX PROPORTION FOR TRIAL NUMBER ONE For 1 cubic Meter
Cement =400kg
water =140 kg
fine agreegate = 856kg
coarse agreegate =1113 kg
Admixture =7.99 kg
Water cement ratio =0.35