Project on Concrete Mix Design for various grades of Concrete
M35 GRADE CONCRETE MIX DESIGN WITH FLY ASH
AIM :
THE AIM OF M35 GRADE CONCRETE MIX DESIGN WITH FLY ASH IS TO DETERMINE THE WORKABILITY AND STRENGTH OF CONCRETE WHEN USING FLY ASH AS ADMIXTURE.
INTRODUCTION:
IN THIS PROJECT, THE USE OF FLY ASH FOR PARTICULAR HIGH STRENGTH CONCRETE IS INVESTIGATED. THE USE OF FLY ASH AS A PARTIAL REPLACEMENT OF PORTLAND CEMENT IN HSC SEEMS A VALID SOLUTION IN PARTICULAR FOR A SUSTAINABLE CONSTRUCTION DESIGN, CONSIDERING THE INTERESTING HIGH STRENGTH PERFORMANCES AND THE ECONOMIC ASPECTS. THE MIX DESIGN CALCULATION OF M35 GRADE CONCRETE WITH FLY ASH ADMIXTURE AS PER INDIAN STANDARD CODEBOOK IS10262 (2009)-GUIDELINES FOR CONCRETE MIX DESIGN PROPORTIONING.
DESIGN PROCEDURE:
- STUPULATION FOR PROPORTIONING OF CONCRETE:
|
A |
GRADE DESIGNATION |
M35 |
|
|
B |
TYPE OF CEMENT |
OPC53 |
|
|
C |
TYPE OF ADMIXTURE |
FLY ASH |
|
|
D |
MAX. NOMINAL SIZE OF AGGREGATE |
20mm |
|
|
E |
MIN. CEMENT CONTENT |
340kg |
TABLE 5-IS456 |
|
F |
MAX. CEMENT CONTENT |
450kg |
AS PER CODE |
|
G |
EXPOSURE CONDITION |
VERY SEVERE |
|
|
H |
PARTIAL REPLACEMENT OF CEMENT BY FLY ASH |
30% |
|
|
I |
WORKABILITY |
100mm |
|
|
J |
MAX. W/C RATIO |
0.45 |
TABLE 5-IS456 |
|
K |
CHEMICAL ADMIXTURE |
PCS TYPE |
- TEST DATA FOR MATERIALS:
MATERIALS SHOULD BE TESTED IN LABORATORY AS PER TESTS GIVEN IN THE CODEBOOK AND THEIR PROPERTIES SHOULD BE FOUND.
|
A |
CEMENT USED |
OPC53 |
IS8112 |
|
B |
SP. GRAVITY OF CEMENT |
3.15 |
TEST – IS:2720 |
|
C |
MINERAL ADMIXTURE |
FLY ASH |
CONFIRMING TO IS 12089 |
|
D |
SPECIFIC GRAVITY OF FLY ASH |
2.90 |
|
|
E |
SP. GRAVITY OF |
TEST – IS2386 |
|
|
COARSE AGGREGATE |
2.74 |
||
|
FINE AGGREGATE |
2.74 |
||
|
ADMIXTURE |
1.12 |
||
|
F |
WATER ABSORPTION |
TEST – IS2386 |
|
|
COARSE AGGREGATE |
0.5% |
||
|
FINE AGGREGATE |
1% |
||
|
G |
SIEVE ANALYSIS |
TEST – IS2386 |
|
|
COARSE AGGREGATE |
CONFIRMING TO TABLE 2-IS383. |
||
|
FINE AGGREGATE |
ZONE II |
CONFIRMING TO TABLE 4-IS383 |
- TARGET STRENGTH FOR MIX PROPORTIONS:
Fck = fck + 1.65S
Where,
S – STANDARD DEVIATION FROM TABLE 1-IS10262
Fck = 35 + 1.65x5
Fck = 43.25N/mm2.
- SELECTION OF WATER CEMENT RATIO:
The water cement ratio for different grades of concrete is given in Table 5-IS456. The water cement ratio directly affects the strength of concrete.
MAX. WATER CEMENT RATIO = 0.45, FROM TABLE 5-IS456
ADOPTED WATER CEMENT RATIO = 0.45
- SELECTION OF WATER CONTENT:
MAX. WATER CONTENT = 186 L, FROM TABLE 2-IS10262
Above water content is for 25 to 50mm slump but that slump we require is 100mm. hence we need to increase the water content to get the required slump for good workability. Here we have 50mm increase in the water content hence we have to increase the water content by 6%.
WATER CONTENT FOR 100mm SLUMP = 186 + (0.06X186)
= 197.16 L
Since superplasticizers are used water content can be reduced to get good strength of concrete.
PERCENTAGE OF REDUCTION IN WATER CONTENT = 20%
WATER CONTENT REQUIRED AFTER SP = 198 – (0.20X198)
= 157.73 L
ADOPTED WATER CONTENT = 160 L
- CALCULATION OF CEMENT AND FLY ASH CONTENT:
ADOPTED WATER CEMENT RATIO = 0.45
TOTAL CEMENTITIOUS MATERIAL = WATER CONTENT/WATER CEMENT RATIO
= 160/0.45
= 355.55kg.
Since the fly ash is used the amount of cementitious material shall be increased to get good workability and strength. The percentage of increase depending on experience and research. Here we increased the cementitious content by 1.1%
FINAL CEMENTITIOUS CONTENT = 356x1.1
= 391.6kg
MIN.CEMENT CONTENT REQUIRED FOR SEVERE EXPOSURE = 340kg , FROM TABLE 5-IS456
ADOPTED CEMENTITIOUS CONTENT = 391.6kg > 340kg.
FLY ASH CONTENT REQUIREMENT = 391.6 x 0.30, 30% REPLACEMENT.
= 117.48~118kg.
CEMENT CONTENT REQD. = CEMENTITIOUS CONTENT - FLY ASH
= 391.6 – 117.48
= 274.12kg.
CALCULATION OF SUPERPLASTICIZER @ 0.6 PERCENT TO THE MASS OF CEMENTITIOUS CONTENT = 391.6x(0.6/100) = 2.35kg.
- COARSE AND FINE AGGREGATE:
COARSE AGGREGATE RATIO = 0.62 (TABLE 3-IS10262 FOR W/C = 0.5)
COARSE AGGREGATE RATIO FOR 0.45 W/C RATIO = 0.63 (ADDING 0.01 FOR EVERY DECREASE 0.05 AND VICE VERSA)
FINAL FINE AGGREGATE RATIO = 0.37 (1-0.63) = 0.37.
- MIX CALCULATION:
VOLUME OF CONCRETE = 1 m3.
TOTAL VOL. OF CEMENT = CEMENT/(SP.Gx1000)
= 275/(3.15x1000)
= 0.087 m3.
TOTAL VOL. OF FLY ASH = FLY ASH/(SP. Gx1000)
= 118/(2.5x1000)
= 0.041 m3.
VOL. OF WATER = WATER/(SP.Gx1000)
= 160/(1x1000)
= 0.160 m3.
VOL. OF SUPERPLASTICIZERS = 2.35/(1.12x1000)
= 0.002 m3.
TOTAL AGGREGATE REQD. = A – (B+C+D+E)
= 1 – (0.087+0.041+0.160+0.002).
COARSE AGGREGATE = FxC.A RATIOxSP. Gx1000
= 0.71x0.63x2.74x1000
= 1225.6kg.
FINE AGGREGATE = FxF.A RATIOxSP. Gx1000
= 0.71x0.37x2.74x1000
= 719.8kg.
RESULT:
- MIX PROPORTIONS:
|
S.NO |
MATERIALS |
QUANTITY |
|
1. |
CEMENT |
275kg |
|
2. |
FLY ASH |
118kg |
|
3. |
FINE AGGREGATE |
720kg |
|
4. |
COARSE AGGREGATE(20mm) |
1226kg |
|
5. |
WATER |
160 L |
|
6. |
PCE BASED SUPERPLASTICIZER |
2 L |
- MIX RATIO:
CEMENT : FLY ASH : F.A : C.A : WATER = 1 : 0.4 : 2.6 : 4.46 : 0.58.
CONCLUSION:
THIS TRIAL MIX RATIO SHOULD MATCH THE WORKABILITY, DURABILITY, MIN. STRENGHT OF M35 GRADE CONCRETE.
IF IT DOES NOT SATISFY THE ABOVE CRITERIA TWO OR MORE TRIALS FOR INCREASE OF 10% SHOULD BE DONE.
M50 GRADE CONCRETE MIX DESIGN
AIM :
THE AIM OF M50 GRADE CONCRETE MIX DESIGN IS TO DETERMINE THE WORKABILITY AND STRENGTH OF CONCRETE.
INTRODUCTION:
THE MIX DESIGN CALCULATION OF M50 GRADE CONCRETE AS PER INDIAN STANDARD CODEBOOK IS10262 (2009)-GUIDELINES FOR CONCRETE MIX DESIGN PROPORTIONING.
DESIGN PROCEDURE:
- STUPULATION FOR PROPORTIONING OF CONCRETE:
|
A |
GRADE DESIGNATION |
M50 |
|
|
B |
TYPE OF CEMENT |
OPC53 |
|
|
C |
MAX. NOMINAL SIZE OF AGGREGATE |
20mm |
|
|
D |
MIN. CEMENT CONTENT |
360kg |
TABLE 5-IS456 |
|
E |
MAX. CEMENT CONTENT |
450kg |
AS PER CODE |
|
F |
EXPOSURE CONDITION |
EXTREME |
|
|
G |
DEGREE OF SUPERVISION |
30% |
|
|
H |
WORKABILITY |
100mm |
|
|
I |
MAX. W/C RATIO |
0.35 |
TABLE 5-IS456 |
- TEST DATA FOR MATERIALS:
MATERIALS SHOULD BE TESTED IN LABORATORY AS PER TESTS GIVEN IN THE CODEBOOK AND THEIR PROPERTIES SHOULD BE FOUND.
|
A |
CEMENT USED |
OPC53 |
IS8112 |
|
B |
SP. GRAVITY OF CEMENT |
3.12 |
TEST – IS:2720 |
|
C |
SP. GRAVITY OF |
TEST – IS2386 |
|
|
COARSE AGGREGATE |
2.74 |
||
|
FINE AGGREGATE |
2.56 |
||
|
D |
WATER ABSORPTION |
TEST – IS2386 |
|
|
COARSE AGGREGATE |
0.5% |
||
|
FINE AGGREGATE |
1% |
||
|
E |
SIEVE ANALYSIS |
TEST – IS2386 |
|
|
COARSE AGGREGATE |
CONFIRMING TO TABLE 2-IS383. |
||
|
FINE AGGREGATE |
ZONE II |
CONFIRMING TO TABLE 4-IS383 |
- TARGET STRENGTH FOR MIX PROPORTIONS:
Fck = fck + 1.65S
Where,
S – STANDARD DEVIATION FROM TABLE 1-IS10262
Fck = 50 + 1.65x5
Fck = 58.25N/mm2.
- SELECTION OF WATER CEMENT RATIO:
The water cement ratio for different grades of concrete is given in Table 5-IS456. The water cement ratio directly affects the strength of concrete.
MAX. WATER CEMENT RATIO = 0.35, FROM TABLE 5-IS456
ADOPTED WATER CEMENT RATIO = 0.35
- SELECTION OF WATER CONTENT:
MAX. WATER CONTENT = 186 L, FROM TABLE 2-IS10262
Above water content is for 25 to 50mm slump but that slump we require is 100mm. hence we need to increase the water content to get the required slump for good workability. Here we have 50mm increase in the water content hence we have to increase the water content by 6%.
WATER CONTENT FOR 100mm SLUMP = 186 + (0.06X186)
= 197.16 L
Since superplasticizers are used water content can be reduced to get good strength of concrete.
PERCENTAGE OF REDUCTION IN WATER CONTENT = 27%
WATER CONTENT REQUIRED AFTER SP = 197 – (0.27X197)
= 143 L
ADOPTED WATER CONTENT = 143 L
- CALCULATION OF CEMENT AND FLY ASH CONTENT:
ADOPTED WATER CEMENT RATIO = 0.35
TOTAL CEMENTITIOUS MATERIAL = WATER CONTENT/WATER CEMENT RATIO
= 143/0.35
= 410kg.
MIN.CEMENT CONTENT REQUIRED FOR EXTREME EXPOSURE = 360kg , FROM TABLE 5-IS456
ADOPTED CEMENTITIOUS CONTENT = 410kg > 340kg.
- COARSE AND FINE AGGREGATE:
COARSE AGGREGATE RATIO = 0.62 (TABLE 3-IS10262 FOR W/C = 0.5)
COARSE AGGREGATE RATIO FOR 0.35 W/C RATIO = 0.65(ADDING 0.01 FOR EVERY DECREASE 0.05 AND VICE VERSA)
FOR PUMPABLE CONCRETE, THESE VALUES SHOUKD BE REDUCED BY 10 PERCENT
VOL. OF COARSE AGGREGATE = (0.65x0.9) = 0.585
FINAL FINE AGGREGATE RATIO = 0.415 (1-0.585) = 0.415.
- MIX CALCULATION:
VOLUME OF CONCRETE = 1 m3.
TOTAL VOL. OF CEMENT = CEMENT/(SP.Gx1000)
= 410/(3.12x1000)
= 0.131 m3.
VOL. OF WATER = WATER/(SP.Gx1000)
= 143/(1x1000)
= 0.143 m3.
VOL. OF SUPERPLASTICIZERS = 8.2/(1.145x1000)
= 0.007 m3.
TOTAL AGGREGATE REQD. = A – (B+C+D+E)
= 1 – (0.13+0.143+0.007)
= 0.719m3.
COARSE AGGREGATE = FxC.A RATIOxSP. Gx1000
= 0.719x0.585x2.74x1000
= 1152.48kg.
FINE AGGREGATE = FxF.A RATIOxSP. Gx1000
= 0.719x0.415x2.56x1000
= 763.86kg.
RESULT:
- MIX PROPORTIONS:
|
S.NO |
MATERIALS |
QUANTITY |
|
1. |
CEMENT |
410kg |
|
2. |
FINE AGGREGATE |
763.8kg |
|
3. |
COARSE AGGREGATE(20mm) |
1152.48kg |
|
4. |
WATER |
143 L |
|
5. |
PCE BASED SUPERPLASTICIZER |
7 kg/m3. |
- MIX RATIO:
CEMENT : F.A : C.A : WATER = 1 : 1.86 : 2.81 : 0.35.
CONCLUSION:
THIS TRIAL MIX RATIO SHOULD MATCH THE WORKABILITY, DURABILITY, MIN. STRENGHT OF M50 GRADE CONCRETE.
IF IT DOES NOT SATISFY THE ABOVE CRITERIA TWO OR MORE TRIALS FOR INCREASE OF 10% SHOULD BE DONE.