Project on Concrete Mix Design for various grades of Concrete
- AIM : Design mix design for M35 grade of concrete with flyash
INTRODUCTION : We design M35 grade of concrete with replacement of 25% flyash. Before designing we need to know the properties of cement, fine aggregate,course aggregate. For that we have to test the materials in lab.
Materials used in making M35 grade of cube concrete:-
1. cement (psc)
2. course aggregate
3. fine aggregate
4. water
5. flyash
6. admixture
Materials testing for concrete cube
The following tests are carried out for :
1. cement (psc)
.) fineness test
.) specific gravity
.) setting time
.) standard consistency
2. Fine aggregate
.) sieve analysis
.) water absorption
.) specific gravity
.) Zone test
3. course aggregate
.) sieve analysis
.) water absorption
.) specific gravity
4. Fly ash
.) specific gravity
5. admixture
.) specific gravity
PROCEDURE : Date collection
Design stipulation :
.)Characteristics compressive strength required in the field at 28 days = 35 N/mm2
.) Maximum size of aggregate = 20mm
.) Degree of workability = 50-750mm (slump)
.) Degree of quantity control = good
.)Type of exposure = severe (RCC)
.) Type of cement = psc
.)Method of placing =hand
.) chemical admixture = Armix EmmeCreteSP111
.) Flyash
Characteristics of materials :
.)cement used PSC
.)specific gravity of cement 3.29
.) specific gravity of coarse aggregate for 20mm 2.84
.)specific gravity of fine aggregate 2.54
.)specific gravity of flyash 1.738
.)specific gravity of admixture 1.25
.)water absorption of 20mm coarse aggregate 0.2%
.)water absorption of sand 1.2%
.) Zone of sand IV
.) Free surface moisture for coarse aggregate 0%
1.) Target strength for mix design :
fck'=fck + 1.65*s
= 35+1.65*5
= 43.25 N/mm2
2.) Determination of water-cement ratio
from table 5 of IS 456 :2000, maximum water- cement ratio for severe exposure condation: 0.45
But we take here w/c: 0.43
3.) Determination of water content
From table 2, IS 10262 :2009, maximum water content for 20mm aggregate: 186 litres(for 25 to 50mm slump range)
∴ Estimated water content for 75 mm slump = 186+3%of 186
= 191.58
= 192 litres
as admixture uses, the we have to reduce water content upto 30%
so we take here :14.5%
∴ Estimated water content after water reduction = 192-14.5%of 192
= 164.16 litres
4.) Determination of cement content and flyash content
∵ w/c =0.43
∴ cementitious material = 164.16/0.43 =381.767
381.767> 320 kg/m3 , then okk
As per experience, we have to increase the cementitious materials when we use flyash
so, we increase 10% of cementitious material
∴ cementitious material content = 381.767+0.1*381.767
= 419.94 kg
∴ fly ash @25% of total cementitious material = 25%*419.9437
= 104.99 kg
∴cement content = 419.9437-104.985925=314.96 kg
5.) proportion of volume of coarse aggregate and fine aggregate content
From IS 10262.2009
Table 3, volume of coarse aggregate corresponding to 20mm size aggregate and fine aggregate zone IV for w/c ratio 0.5 = 0.66
∴ for decrease in every 0.05 w/c ratio = coarse aggregate increases by 0.01
∴ for decrease in 0.07 w/c ratio = 0.01*0.07/0.05=0.014
∴ volume of coarse aggregate = 0.66+0.014
= 0.674
∴ volume of fine aggregate = 1-0.674=0.326
6.) Mix calculation
a.) volume of concrete = 1m3
b.) volume of cement = 314.96/(3.29*1000)
= 0.0957 m3
c.) volume of water = 164.16/(1*1000)
= 0.1642 m3
d.) volume of admixture = 1% of cementitious materials/(1.25*1000)
= 0.01*419.94/(1.25*1000)
= 4.1994/(1.25*1000)
= 0.00336 m3
e.) volume of flyash = 104.99/(1.738*1000)
= 0.0604 m3
f.) volume of aggregate = [1-(b+c+d+e)]
= [1-(0.0957+0.1642+0.00336+0.0604)]
= 0.676 m3
g.) mass of coarse aggregate = 0.676*0.674*2.84*1000
= 1293.972 kg
h.) mass of fine aggregate = 0.676*0.326*2.54*1000
= 559.755 kg
i) Water absorption
for fine aggragate =1.2%
therefore, water absorbed in fine aggregate = 1.2% of 559.755 kg
=6.717kg
for coarse aggragate =1.2%
therefore, water absorbed in coarse aggregate = 0.2% of 1293.972 kg
=2.588 kg
Final water content = 164.16+6.717+2.588=173.465 kg
mass of fine aggregate = 559.755-6.717=553.038 kg
mass of coarse aggregate = 1293.972-2.588=1291.384 kg
for 1m3
| water (kg) | cement (kg) | sand (kg) | coarse ( kg) | flyash (kg) | admixture (kg) |
| 173.465 | 314.96 | 553.038 | 1291.972 | 104.99 | 4.1994 |
RESULTS : Concrete cubes of size 15cmx15cmx15cm were casted, cured under water and tested for compressive strength at 28 days in CTM. The results of individual trials of different cubes and the average strength of three cubes are tabulated in table below .
Results of trial mixers M35 grade:
|
SL. NO |
CEMENT CONTENT (KG) |
FLYASH REPLACEMENT | ADMIXTURE % | WEIGHT OF CUBE (KG) | STRENGTH (mpa) |
| 1 | 341.95 | 25% | 1% | 9.4 | 37 |
| 2 | 341.95 | 25% | 1% | 9.2 | 36 |
| 3 | 341.95 | 25% | 1% | 9.3 | 37 |
AVG. WEIGHT = 9.3 KG AVG. STRENGTH =36.67 MPA
- AIM : Design mix design for M50 grade of concrete without flyash
INTRODUCTION : We design M35 grade of concrete without flyash. Before designing we need to know the properties of cement, fine aggregate,course aggregate. For that we have to test the materials in lab.
Materials used in making M35 grade of cube concrete:-
1. cement (psc)
2. course aggregate
3. fine aggregate
4. water
5. admixture
Materials testing for concrete cube
The following tests are carried out for :
1. cement (psc)
.) fineness test
.) specific gravity
.) setting time
.) standard consistency
2. Fine aggregate
.) sieve analysis
.) water absorption
.) specific gravity
.) Zone test
3. course aggregate
.) sieve analysis
.) water absorption
.) specific gravity
4. admixture
.) specific gravity
PROCEDURE : Date collection
Design stipulation :
.)Characteristics compressive strength required in the field at 28 days = 35 N/mm2
.) Maximum size of aggregate = 20mm
.) Degree of workability = 50-750mm (slump)
.) Degree of quantity control = good
.)Type of exposure = severe (RCC)
.) Type of cement = psc
.)Method of placing =hand
.) chemical admixture = Armix EmmeCreteSP111
Characteristics of materials :
.)cement used PSC
.)specific gravity of cement 3.29
.) specific gravity of coarse aggregate for 20mm 2.84
.)specific gravity of fine aggregate 2.54
.)specific gravity of admixture 1.25
.)water absorption of 20mm coarse aggregate 0.2%
.)water absorption of sand 1.2%
.) Zone of sand IV
.) Free surface moisture for coarse aggregate 0%
1.) Target strength for mix design :
fck'=fck + 1.65*s
= 50+1.65*5
= 58.25 N/mm2
2.) Determination of water-cement ratio
from table 5 of IS 456 :2000, maximum water- cement ratio for severe exposure condation: 0.45
But we take here w/c: 0.33
3.) Determination of water content
From table 2, IS 10262 :2009, maximum water content for 20mm aggregate: 186 litres(for 25 to 50mm slump range)
∴ Estimated water content for 75 mm slump = 186+3%of 186
= 191.58
= 192 litres
as admixture uses, the we have to reduce water content upto 30%
so we take here :14.5%
∴ Estimated water content after water reduction = 192-14.5%of 192
= 164.16 litres
4.) Determination of cement content
∵ w/c =0.33
∴ cement content = 164.16/0.33 =497.454
497.454> 320 kg/m3 , then okk
5.) proportion of volume of coarse aggregate and fine aggregate content
From IS 10262.2009
Table 3, volume of coarse aggregate corresponding to 20mm size aggregate and fine aggregate zone IV for w/c ratio 0.5 = 0.66
∴ for decrease in every 0.05 w/c ratio = coarse aggregate increases by 0.01
∴ for decrease in 0.17 w/c ratio = 0.01*0.17/0.05=0.034
∴ volume of coarse aggregate = 0.66+0.034
= 0.694
∴ volume of fine aggregate = 1-0.694=0.306
6.) Mix calculation
a.) volume of concrete = 1m3
b.) volume of cement = 497.454/(3.29*1000)
= 0.1512 m3
c.) volume of water = 164.16/(1*1000)
= 0.1642 m3
d.) volume of admixture = 1% of cement content/(1.25*1000)
= 0.01*497.454/(1.25*1000)
= 4.974/(1.25*1000)
= 0.00398 m3
e.) volume of aggregate = [1-(b+c+d)]
= [1-(0.1512+0.1642+0.00398)]
= 0.681 m3
f.) mass of coarse aggregate = 0.681*0.694*2.84*1000
= 1342.224 kg
g.) mass of fine aggregate = 0.681*0.306*2.54*1000
= 529.3 kg
h) Water absorption
for fine aggragate =1.2%
therefore, water absorbed in fine aggregate = 1.2% of 529.3 kg
=6.352kg
for coarse aggragate =1.2%
therefore, water absorbed in coarse aggregate = 0.2% of 1342.224 kg
=2.684 kg
Final water content = 164.16+6.352+2.684=173.196 kg
mass of fine aggregate = 529.3-6.352=522.948 kg
mass of coarse aggregate = 1342.224-2.684=1339.54 kg
for 1m3
| water (kg) | cement (kg) | sand (kg) | coarse ( kg) | admixture (kg) |
| 173.196 | 497.454 | 522.948 | 1339.54 | 4.974 |
RESULTS : Concrete cubes of size 15cmx15cmx15cm were casted, cured under water and tested for compressive strength at 28 days in CTM. The results of individual trials of different cubes and the average strength of three cubes are tabulated in table below .
Results of trial mixers M35 grade:
|
SL. NO |
CEMENT CONTENT (KG) |
ADMIXTURE % | WEIGHT OF CUBE (KG) | STRENGTH (mpa) |
| 1 | 497.454 | 1% | 10.2 | 52 |
| 2 | 497.454 | 1% | 10.1 | 56 |
| 3 | 497.454 | 1% | 10.2 | 55 |
AVG. WEIGHT = 10.17 KG AVG. STRENGTH =55 MPA
THANK YOU