Concrete Mix Design – M70 Grade of Concrete (OPC 53 Grade)
Concrete mix design – M70 grade of concrete provided here is for
reference purpose only. Actual site conditions vary and thus this should
be adjusted as per the location and other factors.
A. Design Stipulation:
Characteristic comprehensive Strength @ 28 days = 70 N/mm2
Maximum size of aggregate = 20 mm
Degree of workability = Collapsible
Degree of quality control = Good
Type of exposure = Severe
Minimum cement content as per is 456-2000
B. Test data for concrete ingredients
Specific gravity of cement = 3.15
Specific gravity of fly ash = 2.24
Specific gravity of microsilica = 2.21
Setting time of cement initial = 165 min, final = 270min
Cement compressive strength =
39.0 N/mm2 @ 3 days
51.0 N/mm2 @ 7 days
64.2 N/mm2 @ 28 days
Specific gravity of coarse aggregates (ca) and fine aggregates (fa)
20 mm 2.729
10 mm 2.747
R/sand 2.751
C/sand 2.697
Water absorption
20 mm 1.540, 10mm 1.780, R/sand 3.780, C/sand 4.490
Characteristic strength @ 28 days 70 N/mm2
Target mean strength : Depend upon degree of quality control “good” and considering (std. Dev.As 5 N/mm2)
Characteristic strength given by the relation 70 +(1.65 *5 ) = 78.25 N/mm2
C. Quantities of ingredients (By Absolute Volume Method )
Actual cement used = 486 kg/cum
Actual fly ash used = 90 kg/cum
Actual microsilica used = 24 kg/cum
W/C fixed = 0.26
Absolute volume of cement = 0.154
Absolute volume of air = 0.02
Absolute vol of water. = 0.156
Absolute vol of fly ash. = 0.040
Absolute vol of microsilica = 0.011
Total volume of CA and FA used = 1.00-(0.155+0.044+0.022+0.02 +0.154)
= 0.619 Cum
D. Aggregate percent used.
20 Mm = 24, 10 mm = 36, r/sand = 20, c/sand = 20
(2.729*0.24) + (2.747*0.36) +(2.751* 0.20 )+(2.697*0.20) *0.619*1000
405+612+340+334=1691
Aggt: cement = 2.82 : 1
Mix proportion = 0.26:1:0.57:0.56:1.02:0.67
E. Abstract:
20 mm = 405 kg/cum
10 mm = 612 kg/cum
r/sand = 340 kg /cum
c/sand = 334 kg/cum
water = 154 kg/cum
Admixture 0.50 % BY WT OF (C+F+MS) ASTP-1 OF BASF
Cube Compressive Strength (N/mm2)
3 days = 49.13
7 Days = 59.57
28 Days = 81.49
Note: Mix design is same for Crane bucket and Pump concrete only admixture dosage will fine tuned by 0.05 to 0.10%
We are thankful to Deshmukh D S for submitting this very useful mix design information to us.
Dear All
Again I am back with M-20 Mix Designs as per IS-10262-2009
Dear All
Again I am back with M-25 Mix Designs as per IS-10262-2009.
Dear All
Again I am back with M-30 Mix Designs as per IS-10262-2009
The mix design for M35 Grade Of Concrete for pile foundations provided here is for reference purpose only. Actual site conditions vary and thus this should be adjusted as per the location and other factors.
Grade of Concrete : M35
Characteristic Strength (Fck) : 35 Mpa
Standard Deviation : 1.91 Mpa*
Target Mean Strength : T.M.S.= Fck +1.65 x S.D.
(from I.S 456-2000) = 35+ 1.65×1.91
= 38.15 Mpa
Test Data For Material:
Aggregate Type : Crushed
Specific Gravity
Cement : 3.15
Coarse Aggregate : 2.67
Fine Aggregate : 2.62
Water Absorption:
Coarse Aggregate : 0.5%
Fine Aggregate : 1.0 %
Select Water Cement Ratio = 0.43 for concrete grade M35
(From Fig 2. of I.S. 10262- 1982)
Select Water Content = 172 Kg
(From IS: 10262 for 20 mm nominal size of aggregates Maximum Water Content = 186 Kg/ M3 )
Hence, Cement Content= 172 / 0.43 = 400 Kg / M3
Formula for Mix Proportion of Fine and Coarse Aggregate:
1000(1-a0) = {(Cement Content / Sp. Gr. Of Cement) + Water Content +(Fa / Sp. Gr.* Pf )}
1000(1-a0) = {(Cement Content / Sp. Gr. Of Cement) + Water Content +Ca / Sp. Gr.* Pc )}
Where Ca = Coarse Aggregate Content
Fa = Fine Aggregate Content
Pf = Sand Content as percentage of total Aggregates
= 0.36
Pc = Coarse Aggregate Content as percentage of total Aggregates.
= 0.64
a0 = Percentage air content in concrete (As per IS :10262 for 20 mm nominal size of
aggregates air content is 2 %) = 0.02
Hence, 1000(1-0.02) = {(400 /3.15) + 172 +(Fa / 2.62 x 0.36)}
Fa = 642 Kg/ Cum
As the sand is of Zone II no adjustment is required for sand.
Sand Content = 642 Kg/ Cum
1000(1-0.02) = {(400 /3.15) + 172 +(Ca / 2.67 x 0.64)}
Hence, Ca = 1165 Kg/ Cum
From combined gradation of Coarse aggregates it has been found out that the proportion of 53:47 of 20 mm & 10 mm aggregates produces the best gradation as per IS: 383.
Hence, 20 mm Aggregates = 619 Kg
And 10 mm Aggregates = 546 Kg
To obtain slump in the range of 150-190 mm water reducing admixture brand SP430 from Fosroc with a dose of 0.3 % by weight of Cement shall be used.
Hence the Mix Proportion becomes:
Units – Kg/ M3
A. Design Stipulation:
Characteristic comprehensive Strength @ 28 days = 70 N/mm2
Maximum size of aggregate = 20 mm
Degree of workability = Collapsible
Degree of quality control = Good
Type of exposure = Severe
Minimum cement content as per is 456-2000
B. Test data for concrete ingredients
Specific gravity of cement = 3.15
Specific gravity of fly ash = 2.24
Specific gravity of microsilica = 2.21
Setting time of cement initial = 165 min, final = 270min
Cement compressive strength =
39.0 N/mm2 @ 3 days
51.0 N/mm2 @ 7 days
64.2 N/mm2 @ 28 days
Specific gravity of coarse aggregates (ca) and fine aggregates (fa)
20 mm 2.729
10 mm 2.747
R/sand 2.751
C/sand 2.697
Water absorption
20 mm 1.540, 10mm 1.780, R/sand 3.780, C/sand 4.490
Characteristic strength @ 28 days 70 N/mm2
Target mean strength : Depend upon degree of quality control “good” and considering (std. Dev.As 5 N/mm2)
Characteristic strength given by the relation 70 +(1.65 *5 ) = 78.25 N/mm2
C. Quantities of ingredients (By Absolute Volume Method )
Actual cement used = 486 kg/cum
Actual fly ash used = 90 kg/cum
Actual microsilica used = 24 kg/cum
W/C fixed = 0.26
Absolute volume of cement = 0.154
Absolute volume of air = 0.02
Absolute vol of water. = 0.156
Absolute vol of fly ash. = 0.040
Absolute vol of microsilica = 0.011
Total volume of CA and FA used = 1.00-(0.155+0.044+0.022+0.02 +0.154)
= 0.619 Cum
D. Aggregate percent used.
20 Mm = 24, 10 mm = 36, r/sand = 20, c/sand = 20
(2.729*0.24) + (2.747*0.36) +(2.751* 0.20 )+(2.697*0.20) *0.619*1000
405+612+340+334=1691
Aggt: cement = 2.82 : 1
Mix proportion = 0.26:1:0.57:0.56:1.02:0.67
E. Abstract:
20 mm = 405 kg/cum
10 mm = 612 kg/cum
r/sand = 340 kg /cum
c/sand = 334 kg/cum
water = 154 kg/cum
Admixture 0.50 % BY WT OF (C+F+MS) ASTP-1 OF BASF
Cube Compressive Strength (N/mm2)
3 days = 49.13
7 Days = 59.57
28 Days = 81.49
Note: Mix design is same for Crane bucket and Pump concrete only admixture dosage will fine tuned by 0.05 to 0.10%
We are thankful to Deshmukh D S for submitting this very useful mix design information to us.
Mix Design For Concrete Roads As Per IRC-15-2002
ABSTRACT:
The stresses induced in concrete pavements are mainly flexural. Therefore flexural strength is more often specified than compressive strength in the design of concrete mixes for pavement construction. A simple method of concrete mix design based on flexural strength for normal weight concrete mixes is described in the paper.
INTRODUCTION:
Usual criterion for the strength of concrete in the building industry is the compressive strength, which is considered as a measure of quality concrete. however, in pavement constructions, such as highway and airport runway, the flexural strength of concrete is considered more important, as the stresses induced in concrete pavements are mainly flexural. Therefore, flexural strength is more often specified than compressive strength in the design of concrete mixes for pavement construction. It is not perfectly reliable to predict flexural strength from compressive strength. Further, various codes of the world specified that the paving concrete mixes should preferably be designed in the laboratory and controlled in the field on the basis of its flexural strength. Therefore, there is a need to design concrete mixes based on flexural strength.
The type of aggregate can have a predominant effect, crushed rock aggregate resulting in concrete with higher flexural strength than uncrushed (gravel) aggregates for comparable mixes, assuming that sound materials are used. The strength of cement influences the compressive and flexural strength of concrete i.e. with the same water-cement ratio, higher strength cement will produce concrete of higher compressive and flexural strength.
MIX DESIGN DETAILS
IRC: 15-2002 specified that for concrete roads OPC should be used. This code also allowed PPC as per IS: 1489 may also be used. Accordingly OPC + fly ash may be used in concrete roads. However, IS: 456-2000 specified that fly ash conforming to grade-1 of IS-3812 may be used as part replacement of OPC provided uniform blended with cement is essential. The construction sites where batching plants are used this may be practicable. In ordinary sites where mixer or hand mixing are done uniform blending of fly ash with cement is not practicable. At such construction sites, PPC may be used.
TEST DATA FOR MATERIALS AND OTHER DETAILS
1. The grading of fine aggregate, 10 and 20 mm aggregates are as given in Table. 1 ( given in the end). Fine aggregate is of zone-II as per IS:383-1970. 10 and 20 mm crushed aggregate grading are single sized as per IS: 383-1970.
2. Properties of aggregates
3. Target average flexural strength for all A, B and C mixes
S = S’+ Jao-
= 4.5 + 1.65 x 0.5
= 5.3 N/mm2 at 28 days age
4. For Mix A and B free W/C ratio with crushed aggregate and required average flexural target strength of 5.3 N/mm2 at 28 days from Fig. 1 Curve D ( Figure shown in the end) found to be 0.42. This is lower than specified maximum W/C ratio value of 0.50
Note: In absence of cement strength, but cement conforming to IS Codes, assume from Fig. 1
Curve A and B - For OPC 33 Grade
Curve C and D - For OPC 43 Grade
Take curves C and D for PPC, as PPC is being manufactured in minimum of 43 Grade of strength.
5. Other data’s: The Mixes are to be designed on the basis of saturated and surface dry aggregates. At the time of concreting, moisture content of site aggregates are to be determine. If it carries surface moisture this is to be deducted from the mixing water and if it is dry add in mixing water the quantity of water required for absorption. The weight of aggregates are also adjusted accordingly.
DESIGN OF MIX-A WITH PPC
a) Free W/C ratio for the target flexural strength of 5.3 N/mm2 as worked out is 0.42
b) Free water for 30 mm slump from Table 2 for 20 mm maximum size of aggregate.
2/3*165 + 1/3*195
= 175 kg/m3
From trials it is found that Retarder Super plasticizer at a dosages of 15gm/kg of cement may reduce 15% water without loss of workability
Then water = 175 – (175 x 0.15) = 148.75 kg/m3
For trials say 149 kg/m3
c) PPC = 149/0.42 = 355 kg/m3
This is higher than minimum requirement of 350 kg/m3
d) Formula for calculation of fresh concrete weight in kg/m3
UM = 10 x Ga (100 – A) + CM(1 – Ga/Gc) – WM (Ga – 1)
Where,
Um = Weight of fresh concrete kg/m3
Ga = Weighted average specific gravity of combined fine and coarse aggregate bulk, SSD
Gc = Specific gravity of cement. Determine actual value, in absence assume 3.15 for OPC and 3.00 for PPC (Fly ash based)
A = Air content, percent. Assume entrapped air 1.5% for 20 mm maximum size of aggregate and 2.5% for 10mm maximum size of aggregate. There are always entrapped air in concrete. Therefore ignoring entrapped air value as NIL will lead the calculation of higher value of density.
Wm = Mixing water required in kg/m3
Cm = Cement required, kg/m3
Note:- The exact density may be obtained by filling and fully compacting constant volume suitable metal container from the trial batches of calculated design mixes. The mix be altered with the actual obtained density of the mix.
Um = 10 x Ga (100 – A) + Cm (1 – Ga/Gc) – Wm (Ga – 1)
= 10 x 2.65 (100 – 1.5) + 355(1- 2.65/3.00) – 149 (2.65 -1)
= 2405.9 kg/m3
Say 2405 kg/m3
e) Aggregates = 2405 – 355 – 149 = 1901 kg/m3
f) Fine aggregate = From Table 3 for zone-II Fine aggregate and
20 mm maximum size of aggregate, W/C ratio = 0.42, 30 mm slump found to be 35%.
Fine aggregate = 1901 x 0.35 = 665 kg/m3
Coarse aggregate = 1901 – 665 = 1236 kg/m3
10 and 20 mm aggregate are single sized as per IS: 383-1970. Let they be combined in the ratio of 1.2:1.8 to get 20 mm graded aggregate as per IS: 383-1970
10 mm aggregate = 1236×1.2/3 = 494 kg/m3
20 mm aggregate = 1236×1.8/3 = 742 kg/m3
g) Thus for 4.5 N/mm2 flexural strength quantity of materials per cu.m. of concrete on the basis of saturated and surface dry aggregates:
Water = 149 kg/m3
PPC = 355 kg/m3
Fine Aggregate (sand) = 665 kg/m3
10 mm Aggregate = 494 kg/m3
20 mm Aggregate = 742 kg/m3
Retarder Super Plasticizer = 5.325 kg/m3
MIX- B WITH OPC
a) Water = 175 – (175 x 0.15) = 149 kg/m3 say 149 kg/m3
b) OPC = 149/0.42 = say 355 kg/m3
c) Density: 10 x 2.65 (100 – 1.5) + 355 (1 – 2.65/3.15) – 149 (2.65 – 1)
= 2420.8 kg/m3 say 2420 kg/m3
d) Total Aggregates = 2420 – 355 – 149 = 1916 kg/m3
Fine Aggregate = 1916 x 0.35 = say 670 kg/m3
Coarse aggregate = 1916 – 670 = 1246 kg/m3
10 mm Aggregate = 1246×1.2/3 = 498 kg/m3
20 mm Aggregate = 1246×1.8/3 = 748 kg/m3
e) Thus for 4.5 N/mm2 flexural strength quantity of materials per cu.m of concrete on the basis of SSD aggregates are given below:
Water = 149 kg/m3
OPC = 355 kg/m3
Fine Aggregate (sand) = 670 kg/m3
10 mm Aggregate = 498 kg/m3
20 mm Aggregate = 748 kg/m3
Retarder Super Plasticizer = 3.550 kg/m3
MIX. C WITH OPC + FLYASH
With the given set of materials increase in cementitious materials = 10.7%
Total cementitious materials = 355×1.107 = 393 kg/m3
Fine Aggregate = 0.6994 – 0.4702 = 0.2292
= 0.2292 x 2650 = 607 kg
Note:-
1. Specific gravity of Normal Superplasticizer = 1.15
2. Addition of Flyash reduces 5% of water demand.
Note:-
1. For exact W/C ratio the water in admixture should also be taken into account.
2. The W/C ratio of PPC and OPC is taken the same assuming that the strength properties of both are the same. If it is found that the PPC is giving the low strength then W/C ratio of PPC have to be reduce, which will increase the cement content. For getting early strength and in cold climate the W/C ratio of PPC shall also be required to be reduced.
3. PPC reduces 5% water demand. If this is found by trial then take reduce water for calculation.
4. If the trial mixes does not gives the required properties of the mix, it is then required to be altered accordingly. However, when the experiences grows with the particular set of materials and site conditions very few trials will be required, and a expert of such site very rarely will be required a 2nd trial.
5. It may be noted that, for the fly ash concrete the total cementation material is greater but the OP cement content is smaller, the coarse aggregate content is deliberately, the same, the water is reduced and the density is reduced, because of the lower density of fly ash compared with OPC.
CONCLUSION
1. For 4.5 N/mm2 flexural strength concrete having same material and requirement, but without water reducer, the PPC and OPC required will be 175/0.42 = 417kg/m3
2. With the use of superplasticizer the saving in cement is 62 kg/m3 and water 26 lit/m3 for PPC and OPC.
3. In the Fly ash concrete the saving in cement is 122 kg/m3 and water 33 lit/m3 including utilization of 98 kg/m3 of fly ash witch is a waste material.
4. In the financial year 2009-2010 India has produces 200 million tonnes of cement. In India one kg of cement produce emitted 0.93 kg of CO2. Thus the production of 200 million tonnes of cement had emitted 200 x 0.93 = 186 million tonnes of CO2 to the atmosphere.
5. If 50 million tonnes cement in making concrete uses water reducers 7500000 tonnes of cement can be saved. 3750000 KL of potable water will be saved and the saving of Rs. 3300 crores per year to the construction Industry. 6975000 tonnes of CO2 will be prevented to be emitted to the atmosphere. The benefits in the uses of water reducers not limited to this. When water reduces shrinkage and porosity of concrete are reduces which provides the durability to concrete structures.
6. India is facing serious air, water, soil, food and noise pollution problems. Every efforts therefore are necessary to prevent pollution on top priority basis.
7. As the stress induced in concrete pavements are mainly flexural, it is desirable that their design is based on the flexural strength of concrete. The quality of concrete is normally assessed by measuring its compressive strength. For pavings, however, it is the flexural strength rather than the compression strength of concrete which determine the degree of cracking and thus the performance of road, and it is imperative to control the quality on the basis of flexural strength.
REFERENCES:
Table. 1: Grading of Aggregates
Table. 2: Approximate free-water content (kg/m3) required to give various levels of workability for non-air-entrained (with normal entrapped air) concrete.
Note:- When coarse and fine aggregate of different types are used, the free water content is estimated by the expression.
2/3Wf+1/3Wc
Where,
Wf = Free water content appropriate to type of fine Aggregate
Wc = Free water content appropriate to type of coarse aggregate.
Table. 3: Proportion of fine aggregate (percent) with 10mm and 20mm maximum sizes of aggregates and slump 15-45 mm.
Dear All,
Here i am giving the mix designs as per IS-10262-2009 which gives to change the procedure for calculating the concrete ingredients
The stresses induced in concrete pavements are mainly flexural. Therefore flexural strength is more often specified than compressive strength in the design of concrete mixes for pavement construction. A simple method of concrete mix design based on flexural strength for normal weight concrete mixes is described in the paper.
INTRODUCTION:
Usual criterion for the strength of concrete in the building industry is the compressive strength, which is considered as a measure of quality concrete. however, in pavement constructions, such as highway and airport runway, the flexural strength of concrete is considered more important, as the stresses induced in concrete pavements are mainly flexural. Therefore, flexural strength is more often specified than compressive strength in the design of concrete mixes for pavement construction. It is not perfectly reliable to predict flexural strength from compressive strength. Further, various codes of the world specified that the paving concrete mixes should preferably be designed in the laboratory and controlled in the field on the basis of its flexural strength. Therefore, there is a need to design concrete mixes based on flexural strength.
The type of aggregate can have a predominant effect, crushed rock aggregate resulting in concrete with higher flexural strength than uncrushed (gravel) aggregates for comparable mixes, assuming that sound materials are used. The strength of cement influences the compressive and flexural strength of concrete i.e. with the same water-cement ratio, higher strength cement will produce concrete of higher compressive and flexural strength.
MIX DESIGN DETAILS
IRC: 15-2002 specified that for concrete roads OPC should be used. This code also allowed PPC as per IS: 1489 may also be used. Accordingly OPC + fly ash may be used in concrete roads. However, IS: 456-2000 specified that fly ash conforming to grade-1 of IS-3812 may be used as part replacement of OPC provided uniform blended with cement is essential. The construction sites where batching plants are used this may be practicable. In ordinary sites where mixer or hand mixing are done uniform blending of fly ash with cement is not practicable. At such construction sites, PPC may be used.
| 1 | Characteristic Flexural Strength at 28 days | 4.5N/mm2 |
| 2 | Cement | Three mixes are to be designed |
| MIX-A With PPC (Flyash based) conforming to IS:1489-part-I-1991. 7 days strength 37.5N/mm2. Specific Gravity: 3.00 |
||
| MIX-B With OPC-43- Grade conforming to IS: 8112-1989. 7 days strength 40.5N/mm2. Specific Gravity : 3.15 |
||
| MIX-C With OPC of Mix-B and Fly ash conforming to IS:3812 (Part-I)-2003 Specific Gravity : 2.20 |
||
| Note Requirements of all the three mixes are the same. Fine Aggregate, Coarse Aggregate and Retarder Super plasticizer are the same for all the three mixes. | ||
| 3 | Fly ash replacement | 25% Fly ash is required to be replaced with the total cementitious materials. |
| 4 | Maximum nominal size of aggregates | 20 mm Crushed aggregate |
| 5 | Fine aggregate | River sand of Zone-II as per IS:383-1970 |
| 6 | Minimum cement content | 350 kg/m3 including Fly ash |
| 7 | Maximum free W/C Ratio | 0.50 |
| 8 | Workability | 30 mm slump at pour the concrete will be transported from central batching plant through transit mixer, at a distance of 20 Km during June, July months. The average temperature last year during these months was 400C. |
| 9 | Exposure condition | Moderate |
| 10 | Method of placing | Fully mechanized construction |
| 11 | Degree of supervision | Good |
| 12 | Maximum of cement content (Fly ash not included) | 425 kg/m3 |
| 13 | Chemical admixture | Retarder Super plasticizer conforming to IS:9103-1999. With the given requirements and materials, the manufacturer of Retarder Super plasticizer recommends dosages of 10 gm per kg of OPC, which will reduce 15% of water without loss of workability. For fly ash included cement dosages will be required to be adjusted by experience/ trials. |
| 14 | Values of Jaxo- | 1.65 x 0.5 N/mm2 |
TEST DATA FOR MATERIALS AND OTHER DETAILS
1. The grading of fine aggregate, 10 and 20 mm aggregates are as given in Table. 1 ( given in the end). Fine aggregate is of zone-II as per IS:383-1970. 10 and 20 mm crushed aggregate grading are single sized as per IS: 383-1970.
2. Properties of aggregates
|
Tests
|
Fine aggregate
|
10mm aggregate
|
40mm aggregate
|
| Specific Gravity |
2.65
|
2.65
|
2.65
|
| Water Absorption % |
0.8
|
0.5
|
0.5
|
S = S’+ Jao-
= 4.5 + 1.65 x 0.5
= 5.3 N/mm2 at 28 days age
4. For Mix A and B free W/C ratio with crushed aggregate and required average flexural target strength of 5.3 N/mm2 at 28 days from Fig. 1 Curve D ( Figure shown in the end) found to be 0.42. This is lower than specified maximum W/C ratio value of 0.50
Note: In absence of cement strength, but cement conforming to IS Codes, assume from Fig. 1
Curve A and B - For OPC 33 Grade
Curve C and D - For OPC 43 Grade
Take curves C and D for PPC, as PPC is being manufactured in minimum of 43 Grade of strength.
5. Other data’s: The Mixes are to be designed on the basis of saturated and surface dry aggregates. At the time of concreting, moisture content of site aggregates are to be determine. If it carries surface moisture this is to be deducted from the mixing water and if it is dry add in mixing water the quantity of water required for absorption. The weight of aggregates are also adjusted accordingly.
DESIGN OF MIX-A WITH PPC
a) Free W/C ratio for the target flexural strength of 5.3 N/mm2 as worked out is 0.42
b) Free water for 30 mm slump from Table 2 for 20 mm maximum size of aggregate.
2/3*165 + 1/3*195
= 175 kg/m3
From trials it is found that Retarder Super plasticizer at a dosages of 15gm/kg of cement may reduce 15% water without loss of workability
Then water = 175 – (175 x 0.15) = 148.75 kg/m3
For trials say 149 kg/m3
c) PPC = 149/0.42 = 355 kg/m3
This is higher than minimum requirement of 350 kg/m3
d) Formula for calculation of fresh concrete weight in kg/m3
UM = 10 x Ga (100 – A) + CM(1 – Ga/Gc) – WM (Ga – 1)
Where,
Um = Weight of fresh concrete kg/m3
Ga = Weighted average specific gravity of combined fine and coarse aggregate bulk, SSD
Gc = Specific gravity of cement. Determine actual value, in absence assume 3.15 for OPC and 3.00 for PPC (Fly ash based)
A = Air content, percent. Assume entrapped air 1.5% for 20 mm maximum size of aggregate and 2.5% for 10mm maximum size of aggregate. There are always entrapped air in concrete. Therefore ignoring entrapped air value as NIL will lead the calculation of higher value of density.
Wm = Mixing water required in kg/m3
Cm = Cement required, kg/m3
Note:- The exact density may be obtained by filling and fully compacting constant volume suitable metal container from the trial batches of calculated design mixes. The mix be altered with the actual obtained density of the mix.
Um = 10 x Ga (100 – A) + Cm (1 – Ga/Gc) – Wm (Ga – 1)
= 10 x 2.65 (100 – 1.5) + 355(1- 2.65/3.00) – 149 (2.65 -1)
= 2405.9 kg/m3
Say 2405 kg/m3
e) Aggregates = 2405 – 355 – 149 = 1901 kg/m3
f) Fine aggregate = From Table 3 for zone-II Fine aggregate and
20 mm maximum size of aggregate, W/C ratio = 0.42, 30 mm slump found to be 35%.
Fine aggregate = 1901 x 0.35 = 665 kg/m3
Coarse aggregate = 1901 – 665 = 1236 kg/m3
10 and 20 mm aggregate are single sized as per IS: 383-1970. Let they be combined in the ratio of 1.2:1.8 to get 20 mm graded aggregate as per IS: 383-1970
10 mm aggregate = 1236×1.2/3 = 494 kg/m3
20 mm aggregate = 1236×1.8/3 = 742 kg/m3
g) Thus for 4.5 N/mm2 flexural strength quantity of materials per cu.m. of concrete on the basis of saturated and surface dry aggregates:
Water = 149 kg/m3
PPC = 355 kg/m3
Fine Aggregate (sand) = 665 kg/m3
10 mm Aggregate = 494 kg/m3
20 mm Aggregate = 742 kg/m3
Retarder Super Plasticizer = 5.325 kg/m3
MIX- B WITH OPC
a) Water = 175 – (175 x 0.15) = 149 kg/m3 say 149 kg/m3
b) OPC = 149/0.42 = say 355 kg/m3
c) Density: 10 x 2.65 (100 – 1.5) + 355 (1 – 2.65/3.15) – 149 (2.65 – 1)
= 2420.8 kg/m3 say 2420 kg/m3
d) Total Aggregates = 2420 – 355 – 149 = 1916 kg/m3
Fine Aggregate = 1916 x 0.35 = say 670 kg/m3
Coarse aggregate = 1916 – 670 = 1246 kg/m3
10 mm Aggregate = 1246×1.2/3 = 498 kg/m3
20 mm Aggregate = 1246×1.8/3 = 748 kg/m3
e) Thus for 4.5 N/mm2 flexural strength quantity of materials per cu.m of concrete on the basis of SSD aggregates are given below:
Water = 149 kg/m3
OPC = 355 kg/m3
Fine Aggregate (sand) = 670 kg/m3
10 mm Aggregate = 498 kg/m3
20 mm Aggregate = 748 kg/m3
Retarder Super Plasticizer = 3.550 kg/m3
MIX. C WITH OPC + FLYASH
With the given set of materials increase in cementitious materials = 10.7%
Total cementitious materials = 355×1.107 = 393 kg/m3
|
Materials
|
Weight (kg/m3)
|
Volume (m3)
|
| OPC = 393 x 0.75 |
295/3150
|
0.0937
|
| Flyash = 393 x 0.25 |
98/2200
|
0.0445
|
| Free Water = 149 x 0.95 |
142/1000
|
0.142
|
| Retarder Super Plasticizer = 6.2 kg |
6.2/1150
|
0.0054
|
| Air = 1.5% |
0.015
|
|
|
Total
|
0.3006
|
|
| Total Aggregates = 1 – 0.3006 |
0.6994
|
|
|
|
||
| Coarse Aggregate |
1246/2650
|
0.4702
|
= 0.2292 x 2650 = 607 kg
Note:-
1. Specific gravity of Normal Superplasticizer = 1.15
2. Addition of Flyash reduces 5% of water demand.
For 4.5 N/mm2 flexural strength quantity of material per cu.m of concrete on the basis of saturated and surface dry aggregates of
Mix ‘A’, ‘B’ and ‘C’ are given below:
|
Materials
|
MIX. ‘A’ with PPC
|
Mix. ‘B’ with OPC
|
Mix. ‘C’ with OPC+Flyash
|
| Water kg/m3 |
149
|
149
|
142
|
| PPC kg/m3 |
355
|
–
|
–
|
| OPC kg/m3 |
–
|
355
|
295
|
| Flyash kg/m3 |
–
|
–
|
98
|
| Fine Agg. kg/m3 |
665
|
670
|
607
|
| 10mm Agg. kg/m3 |
494
|
498
|
498
|
| 20 mm Agg. kg/m3 |
742
|
748
|
748
|
| Retarder Super- plasticizer kg/m3 |
5.325
|
3.550
|
6.2
|
| W/Cementations ratio |
0.42
|
0.42
|
0.361
|
1. For exact W/C ratio the water in admixture should also be taken into account.
2. The W/C ratio of PPC and OPC is taken the same assuming that the strength properties of both are the same. If it is found that the PPC is giving the low strength then W/C ratio of PPC have to be reduce, which will increase the cement content. For getting early strength and in cold climate the W/C ratio of PPC shall also be required to be reduced.
3. PPC reduces 5% water demand. If this is found by trial then take reduce water for calculation.
4. If the trial mixes does not gives the required properties of the mix, it is then required to be altered accordingly. However, when the experiences grows with the particular set of materials and site conditions very few trials will be required, and a expert of such site very rarely will be required a 2nd trial.
5. It may be noted that, for the fly ash concrete the total cementation material is greater but the OP cement content is smaller, the coarse aggregate content is deliberately, the same, the water is reduced and the density is reduced, because of the lower density of fly ash compared with OPC.
CONCLUSION
1. For 4.5 N/mm2 flexural strength concrete having same material and requirement, but without water reducer, the PPC and OPC required will be 175/0.42 = 417kg/m3
2. With the use of superplasticizer the saving in cement is 62 kg/m3 and water 26 lit/m3 for PPC and OPC.
3. In the Fly ash concrete the saving in cement is 122 kg/m3 and water 33 lit/m3 including utilization of 98 kg/m3 of fly ash witch is a waste material.
4. In the financial year 2009-2010 India has produces 200 million tonnes of cement. In India one kg of cement produce emitted 0.93 kg of CO2. Thus the production of 200 million tonnes of cement had emitted 200 x 0.93 = 186 million tonnes of CO2 to the atmosphere.
5. If 50 million tonnes cement in making concrete uses water reducers 7500000 tonnes of cement can be saved. 3750000 KL of potable water will be saved and the saving of Rs. 3300 crores per year to the construction Industry. 6975000 tonnes of CO2 will be prevented to be emitted to the atmosphere. The benefits in the uses of water reducers not limited to this. When water reduces shrinkage and porosity of concrete are reduces which provides the durability to concrete structures.
6. India is facing serious air, water, soil, food and noise pollution problems. Every efforts therefore are necessary to prevent pollution on top priority basis.
7. As the stress induced in concrete pavements are mainly flexural, it is desirable that their design is based on the flexural strength of concrete. The quality of concrete is normally assessed by measuring its compressive strength. For pavings, however, it is the flexural strength rather than the compression strength of concrete which determine the degree of cracking and thus the performance of road, and it is imperative to control the quality on the basis of flexural strength.
REFERENCES:
| 1 | IS : 383-1970 | Specifications for coarse and fine aggregates from natural sources for concrete (second revision) BIS, New Delhi | ||
| 2 | IS: 456-2000 | Code of practice for plain and reinforced concrete (fourth revision), BIS, New Delhi | ||
| 3 | IS: 9103-1999 | Specification for admixtures for concrete (first revision) BIS, New Delhi | ||
| 4 | IS: 8112-1989 | Specifications for 43 Grade ordinary portland cement (first revision) BIS, New Delhi | ||
| 5 | IS: 2386 (Part-III) 1963 | method of test for aggregate for concrete. Specific gravity, density, voids, absorption and bulking, BIS, New Delhi | ||
| 6 | IS: 3812 (Part-I) 2003 | Specification for pulverized fuel ash: Part-I for use as pozzolana in cement, cement mortar and concrete (second revision) BIS, New Delhi | ||
| 7 | IS: 1489-Part-I 1991 | Specifications for portland pozzolana cement (Part-I) Flyash based. (Third revision), BIS, New Delhi | ||
| 8 | IRC: 15-2002 – Standard specifications and code of practice for
construction of concrete road (third revision) |
|||
| 9 | Kishore Kaushal, “Concrete Mix Design Based on Flexural Strength for Air-Entrained Concrete”, Proceeding of 13th Conference on our World in Concrete and Structures, 25-26, August, 1988, Singapore. | |||
| 10 | Kishore Kaushal, “Method of Concrete Mix Design Based on Flexural Strength”, Proceeding of the International Conference on Road and Road Transport Problems ICORT, 12-15 December, 1988, New Delhi, pp. 296-305. | |||
| 11 | Kishore Kaushal, “Mix Design Based on Flexural Strength of Air-Entrained Concrete”. The Indian Concrete Journal, February, 1989, pp. 93-97. | |||
| 12 | Kishore Kaushal, “Concrete Mix Design Containing Chemical Admixtures”, Journal of the National Building Organization, April, 1990, pp. 1-12. | |||
| 13 | Kishore Kaushal, “Concrete Mix Design for Road Bridges”, INDIAN HIGHWAYS, Vol. 19, No. 11, November, 1991, pp. 31-37 | |||
| 14 | Kishore Kaushal, “ Mix Design for Pumped Concrete”, Journal of Central Board of Irrigation and Power, Vol. 49, No.2, April, 1992, pp. 81-92 | |||
| 15 | Kishore Kaushal, “Concrete Mix Design with Fly Ash”, Indian Construction, January, 1995, pp. 16-17 | |||
| 16 | Kishore Kaushal, “High-Strength Concrete”, Bulletin of Indian Concrete Institute No. 51, April-June, 1995, pp. 29-31 | |||
| 17 | Kishore Kaushal, “Concrete Mix Design Simplified”, Indian Concrete Institute Bulletin No. 56, July-September, 1996, pp. 25-30. |
|||
| 18 | Kishore Kaushal, “Concrete Mix Design with Fly Ash & Superplasticizer”, ICI Bulletin No. 59, April-June 1997, pp. 29-30 | |||
| 19 | Kishore Kaushal. “Mix Design for Pumped Concrete”, CE & CR October, 2006, pp. 44-50. | |||
|
IS Sieve Designation
|
Percentage Passing
|
||
|
Fine Aggregate
|
Crushed Aggregate
|
||
|
10 mm
|
20 mm
|
||
| 40 mm |
–
|
–
|
100
|
| 20 mm |
–
|
–
|
100
|
| 12.5 mm |
–
|
100
|
–
|
| 10 mm |
100
|
89
|
0
|
| 4.75 mm |
98
|
6
|
|
| 2.36 mm |
86
|
0
|
|
| 1.18 mm |
71
|
|
|
| 600 Micron |
40
|
|
|
| 300 Micron |
21
|
|
|
| 150 Micron |
5
|
|
|
| Maximum size of aggregate(mm) |
Type of aggregate
|
Slump(mm)
|
15-45
|
|
10
|
Uncrushed Crushed | 185 215 | |
| 20 | Uncrushed Crushed | 165 195 |
2/3Wf+1/3Wc
Where,
Wf = Free water content appropriate to type of fine Aggregate
Wc = Free water content appropriate to type of coarse aggregate.
Table. 3: Proportion of fine aggregate (percent) with 10mm and 20mm maximum sizes of aggregates and slump 15-45 mm.
| Grading Zone of F.A |
W/C Ratio
|
10 mm aggregate
|
20 mm aggregate
|
|
I
|
0.3
|
47-57
|
37-45
|
|
0.4
|
49-59
|
39-47
|
|
|
0.5
|
51-61
|
41-49
|
|
|
II
|
0.3
|
39-48
|
30-37
|
|
0.4
|
41-50
|
32-39
|
|
|
0.5
|
43-52
|
34-41
|
|
|
III
|
0.3
|
32-38
|
25-30
|
|
0.4
|
34-40
|
27-32
|
|
|
0.5
|
36-42
|
29-34
|
|
|
IV
|
0.3
|
28-32
|
22-26
|
|
0.4
|
30-34
|
24-28
|
|
|
0.5
|
32-36
|
26-30
|
M 15 Mix Designs as per IS-10262-2009
Dear All,
Here i am giving the mix designs as per IS-10262-2009 which gives to change the procedure for calculating the concrete ingredients
|
M-15 CONCRETE MIX DESIGN
|
||
|
As per IS 10262-2009 & MORT&H
|
||
|
A-1
|
Stipulations for Proportioning | |
|
1
|
Grade Designation | M15 |
|
2
|
Type of Cement | OPC 53 grade confirming to IS-12269-1987 |
|
3
|
Maximum Nominal Aggregate Size | 20 mm |
|
4
|
Minimum Cement Content (MORT&H 1700-3 A) | 250 kg/m3 |
|
5
|
Maximum Water Cement Ratio (MORT&H 1700-3 A) | 0.5 |
|
6
|
Workability (MORT&H 1700-4) | 25 mm (Slump) |
|
7
|
Exposure Condition | Normal |
|
8
|
Degree of Supervision | Good |
|
9
|
Type of Aggregate | Crushed Angular Aggregate |
|
10
|
Maximum Cement Content (MORT&H Cl. 1703.2) | 540 kg/m3 |
|
11
|
Chemical Admixture Type | Superplasticiser Confirming to IS-9103 |
|
A-2
|
Test Data for Materials | |
|
1
|
Cement Used | Coromandal King OPC 53 grade |
|
2
|
Sp. Gravity of Cement | 3.15 |
|
3
|
Sp. Gravity of Water | 1.00 |
|
4
|
Chemical Admixture | Not Used |
|
5
|
Sp. Gravity of 20 mm Aggregate | 2.884 |
|
6
|
Sp. Gravity of 10 mm Aggregate | 2.878 |
|
7
|
Sp. Gravity of Sand | 2.605 |
|
8
|
Water Absorption of 20 mm Aggregate | 0.97% |
|
9
|
Water Absorption of 10 mm Aggregate | 0.83% |
|
10
|
Water Absorption of Sand | 1.23% |
|
11
|
Free (Surface) Moisture of 20 mm Aggregate | nil |
|
12
|
Free (Surface) Moisture of 10 mm Aggregate | nil |
|
13
|
Free (Surface) Moisture of Sand | nil |
|
14
|
Sieve Analysis of Individual Coarse Aggregates | Separate Analysis Done |
|
15
|
Sieve Analysis of Combined Coarse Aggregates | Separate Analysis Done |
|
15
|
Sp.Gravity of Combined Coarse Aggregates | 2.882 |
|
16
|
Sieve Analysis of Fine Aggregates | Separate Analysis Done |
|
A-3
|
Target Strength for Mix Proportioning | |
|
1
|
Target Mean Strength (MORT&H 1700-5) | 25N/mm2 |
|
2
|
Characteristic Strength @ 28 days | 15N/mm2 |
|
A-4
|
Selection of Water Cement Ratio | |
|
1
|
Maximum Water Cement Ratio (MORT&H 1700-3 A) | 0.5 |
|
2
|
Adopted Water Cement Ratio | 0.5 |
|
A-5
|
Selection of Water Content | |
|
1
|
Maximum Water content (10262-table-2) | 186 Lit. |
|
2
|
Estimated Water content for 25 mm Slump | 135 Lit. |
|
3
|
Superplasticiser used | nil |
|
A-6
|
Calculation of Cement Content | |
|
1
|
Water Cement Ratio | 0.5 |
|
2
|
Cement Content (135/0.5) | 270 kg/m3 |
|
|
Which is greater then 250 kg/m3 | |
|
A-7
|
Proportion of Volume of Coarse Aggregate & Fine Aggregate Content | |
|
1
|
Vol. of C.A. as per table 3 of IS 10262 | 62.00% |
|
2
|
Adopted Vol. of Coarse Aggregate | 65.00% |
|
|
Adopted Vol. of Fine Aggregate ( 1-0.65) | 35.00% |
|
A-8
|
Mix Calculations | |
|
1
|
Volume of Concrete in m3 | 1.00 |
|
2
|
Volume of Cement in m3 | 0.09 |
|
|
(Mass of Cement) / (Sp. Gravity of Cement)x1000 | |
|
3
|
Volume of Water in m3 | 0.135 |
|
|
(Mass of Water) / (Sp. Gravity of Water)x1000 | |
|
4
|
Volume of Admixture @ 0% in m3 | nil |
|
|
(Mass of Admixture)/(Sp. Gravity of Admixture)x1000 | |
|
5
|
Volume of All in Aggregate in m3 | 0.779 |
|
|
Sr. no. 1 – (Sr. no. 2+3+4) | |
|
6
|
Volume of Coarse Aggregate in m3 | 0.507 |
|
|
Sr. no. 5 x 0.65 | |
|
7
|
Volume of Fine Aggregate in m3 | 0.273 |
|
|
Sr. no. 5 x 0.35 | |
|
A-9
|
Mix Proportions for One Cum of Concrete (SSD Condition) | |
|
1
|
Mass of Cement in kg/m3 | 270 |
|
2
|
Mass of Water in kg/m3 | 135 |
|
3
|
Mass of Fine Aggregate in kg/m3 | 711 |
|
4
|
Mass of Coarse Aggregate in kg/m3 | 1460 |
|
|
Mass of 20 mm in kg/m3 | 1051 |
|
|
Mass of 10 mm in kg/m3 | 409 |
|
5
|
Mass of Admixture in kg/m3 | nil |
|
6
|
Water Cement Ratio | 0.5 |
|
|
||
M-20 Mix Designs as per IS-10262-2009
Dear All
Again I am back with M-20 Mix Designs as per IS-10262-2009
|
M-20 CONCRETE MIX DESIGN
|
||
|
As per IS 10262-2009 & MORT&H
|
||
|
A-1
|
Stipulations for Proportioning | |
|
1
|
Grade Designation | M20 |
|
2
|
Type of Cement | OPC 53 grade confirming to IS-12269-1987 |
|
3
|
Maximum Nominal Aggregate Size | 20 mm |
|
4
|
Minimum Cement Content (MORT&H 1700-3 A) | 250 kg/m3 |
|
5
|
Maximum Water Cement Ratio (MORT&H 1700-3 A) | 0.5 |
|
6
|
Workability (MORT&H 1700-4) | 25 mm (Slump) |
|
7
|
Exposure Condition | Normal |
|
8
|
Degree of Supervision | Good |
|
9
|
Type of Aggregate | Crushed Angular Aggregate |
|
10
|
Maximum Cement Content (MORT&H Cl. 1703.2) | 540 kg/m3 |
|
11
|
Chemical Admixture Type | Superplasticiser Confirming to IS-9103 |
|
A-2
|
Test Data for Materials | |
|
1
|
Cement Used | Coromandal King OPC 53 grade |
|
2
|
Sp. Gravity of Cement | 3.15 |
|
3
|
Sp. Gravity of Water | 1.00 |
|
4
|
Chemical Admixture | Not Used |
|
5
|
Sp. Gravity of 20 mm Aggregate | 2.884 |
|
6
|
Sp. Gravity of 10 mm Aggregate | 2.878 |
|
7
|
Sp. Gravity of Sand | 2.605 |
|
8
|
Water Absorption of 20 mm Aggregate | 0.97% |
|
9
|
Water Absorption of 10 mm Aggregate | 0.83% |
|
10
|
Water Absorption of Sand | 1.23% |
|
11
|
Free (Surface) Moisture of 20 mm Aggregate | nil |
|
12
|
Free (Surface) Moisture of 10 mm Aggregate | nil |
|
13
|
Free (Surface) Moisture of Sand | nil |
|
14
|
Sieve Analysis of Individual Coarse Aggregates | Separate Analysis Done |
|
15
|
Sieve Analysis of Combined Coarse Aggregates | Separate Analysis Done |
|
15
|
Sp. Gravity of Combined Coarse Aggregates | 2.882 |
|
16
|
Sieve Analysis of Fine Aggregates | Separate Analysis Done |
|
A-3
|
Target Strength for Mix Proportioning | |
|
1
|
Target Mean Strength (MORT&H 1700-5) | 30N/mm2 |
|
2
|
Characteristic Strength @ 28 days | 20N/mm2 |
|
A-4
|
Selection of Water Cement Ratio | |
|
1
|
Maximum Water Cement Ratio (MORT&H 1700-3 A) | 0.5 |
|
2
|
Adopted Water Cement Ratio | 0.5 |
|
A-5
|
Selection of Water Content | |
|
1
|
Maximum Water content (10262-table-2) | 186 Lit. |
|
2
|
Estimated Water content for 25 mm Slump | 145 Lit. |
|
3
|
Superplasticiser used | nil |
|
A-6
|
Calculation of Cement Content | |
|
1
|
Water Cement Ratio | 0.5 |
|
2
|
Cement Content (145/0.5) | 290 kg/m3 |
|
|
Which is greater then 250 kg/m3 | |
|
A-7
|
Proportion of Volume of Coarse Aggregate & Fine Aggregate Content | |
|
1
|
Vol. of C.A. as per table 3 of IS 10262 | 62.00% |
|
2
|
Adopted Vol. of Coarse Aggregate | 65.00% |
|
|
Adopted Vol. of Fine Aggregate ( 1-0.65) | 35.00% |
|
A-8
|
Mix Calculations | |
|
1
|
Volume of Concrete in m3 | 1.00 |
|
2
|
Volume of Cement in m3 | 0.09 |
|
|
(Mass of Cement) / (Sp. Gravity of Cement)x1000 | |
|
3
|
Volume of Water in m3 | 0.145 |
|
|
(Mass of Water) / (Sp. Gravity of Water)x1000 | |
|
4
|
Volume of Admixture @ 0% in m3 | nil |
|
|
(Mass of Admixture)/(Sp. Gravity of Admixture)x1000 | |
|
5
|
Volume of All in Aggregate in m3 | 0.763 |
|
|
Sr. no. 1 – (Sr. no. 2+3+4) | |
|
6
|
Volume of Coarse Aggregate in m3 | 0.496 |
|
|
Sr. no. 5 x 0.65 | |
|
7
|
Volume of Fine Aggregate in m3 | 0.267 |
|
|
Sr. no. 5 x 0.35 | |
|
A-9
|
Mix Proportions for One Cum of Concrete (SSD Condition) | |
|
1
|
Mass of Cement in kg/m3 | 290 |
|
2
|
Mass of Water in kg/m3 | 145 |
|
3
|
Mass of Fine Aggregate in kg/m3 | 696 |
|
4
|
Mass of Coarse Aggregate in kg/m3 | 1429 |
|
|
Mass of 20 mm in kg/m3 | 1029 |
|
|
Mass of 10 mm in kg/m3 | 400 |
|
5
|
Mass of Admixture in kg/m3 | nil |
|
6
|
Water Cement Ratio | 0.5 |
M-25 Mix Designs as per IS-10262-2009
Dear All
Again I am back with M-25 Mix Designs as per IS-10262-2009.
|
M-25 CONCRETE MIX DESIGN
|
||
|
As per IS 10262-2009 & MORT&H
|
||
|
A-1
|
Stipulations for Proportioning | |
|
1
|
Grade Designation | M25 |
|
2
|
Type of Cement | OPC 53 grade confirming to IS-12269-1987 |
|
3
|
Maximum Nominal Aggregate Size | 20 mm |
|
4
|
Minimum Cement Content (MORT&H 1700-3 A) | 310 kg/m3 |
|
5
|
Maximum Water Cement Ratio (MORT&H 1700-3 A) | 0.45 |
|
6
|
Workability (MORT&H 1700-4) | 50-75 mm (Slump) |
|
7
|
Exposure Condition | Normal |
|
8
|
Degree of Supervision | Good |
|
9
|
Type of Aggregate | Crushed Angular Aggregate |
|
10
|
Maximum Cement Content (MORT&H Cl. 1703.2) | 540 kg/m3 |
|
11
|
Chemical Admixture Type | Superplasticiser Confirming to IS-9103 |
|
A-2
|
Test Data for Materials | |
|
1
|
Cement Used | Coromandal King OPC 53 grade |
|
2
|
Sp. Gravity of Cement | 3.15 |
|
3
|
Sp. Gravity of Water | 1.00 |
|
4
|
Chemical Admixture | BASF Chemicals Company |
|
5
|
Sp. Gravity of 20 mm Aggregate | 2.884 |
|
6
|
Sp. Gravity of 10 mm Aggregate | 2.878 |
|
7
|
Sp. Gravity of Sand | 2.605 |
|
8
|
Water Absorption of 20 mm Aggregate | 0.97% |
|
9
|
Water Absorption of 10 mm Aggregate | 0.83% |
|
10
|
Water Absorption of Sand | 1.23% |
|
11
|
Free (Surface) Moisture of 20 mm Aggregate | nil |
|
12
|
Free (Surface) Moisture of 10 mm Aggregate | nil |
|
13
|
Free (Surface) Moisture of Sand | nil |
|
14
|
Sieve Analysis of Individual Coarse Aggregates | Separate Analysis Done |
|
15
|
Sieve Analysis of Combined Coarse Aggregates | Separate Analysis Done |
|
15
|
Sp. Gravity of Combined Coarse Aggregates | 2.882 |
|
16
|
Sieve Analysis of Fine Aggregates | Separate Analysis Done |
|
A-3
|
Target Strength for Mix Proportioning | |
|
1
|
Target Mean Strength (MORT&H 1700-5) | 36N/mm2 |
|
2
|
Characteristic Strength @ 28 days | 25N/mm2 |
|
A-4
|
Selection of Water Cement Ratio | |
|
1
|
Maximum Water Cement Ratio (MORT&H 1700-3 A) | 0.45 |
|
2
|
Adopted Water Cement Ratio | 0.43 |
|
A-5
|
Selection of Water Content | |
|
1
|
Maximum Water content (10262-table-2) | 186 Lit. |
|
2
|
Estimated Water content for 50-75 mm Slump | 138 Lit. |
|
3
|
Superplasticiser used | 0.5 % by wt. of cement |
|
A-6
|
Calculation of Cement Content | |
|
1
|
Water Cement Ratio | 0.43 |
|
2
|
Cement Content (138/0.43) | 320 kg/m3 |
|
|
Which is greater then 310 kg/m3 | |
|
A-7
|
Proportion of Volume of Coarse Aggregate & Fine Aggregate Content | |
|
1
|
Vol. of C.A. as per table 3 of IS 10262 | 62.00% |
|
2
|
Adopted Vol. of Coarse Aggregate | 62.00% |
|
|
Adopted Vol. of Fine Aggregate ( 1-0.62) | 38.00% |
|
A-8
|
Mix Calculations | |
|
1
|
Volume of Concrete in m3 | 1.00 |
|
2
|
Volume of Cement in m3 | 0.10 |
|
|
(Mass of Cement) / (Sp. Gravity of Cement)x1000 | |
|
3
|
Volume of Water in m3 | 0.138 |
|
|
(Mass of Water) / (Sp. Gravity of Water)x1000 | |
|
4
|
Volume of Admixture @ 0.5% in m3 | 0.00134 |
|
|
(Mass of Admixture)/(Sp. Gravity of Admixture)x1000 | |
|
5
|
Volume of All in Aggregate in m3 | 0.759 |
|
|
Sr. no. 1 – (Sr. no. 2+3+4) | |
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6
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Volume of Coarse Aggregate in m3 | 0.471 |
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Sr. no. 5 x 0.62 | |
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7
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Volume of Fine Aggregate in m3 | 0.288 |
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Sr. no. 5 x 0.38 | |
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A-9
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Mix Proportions for One Cum of Concrete (SSD Condition) | |
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1
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Mass of Cement in kg/m3 | 320 |
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2
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Mass of Water in kg/m3 | 138 |
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3
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Mass of Fine Aggregate in kg/m3 | 751 |
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4
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Mass of Coarse Aggregate in kg/m3 | 1356 |
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Mass of 20 mm in kg/m3 | 977 |
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Mass of 10 mm in kg/m3 | 380 |
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5
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Mass of Admixture in kg/m3 | 1.60 |
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6
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Water Cement Ratio | 0.43 |
M-30 Mix Designs as per IS-10262-2009
Dear All
Again I am back with M-30 Mix Designs as per IS-10262-2009
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M-30 CONCRETE MIX DESIGN
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As per IS 10262-2009 & MORT&H
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A-1
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Stipulations for Proportioning | |
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1
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Grade Designation | M30 |
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2
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Type of Cement | OPC 53 grade confirming to IS-12269-1987 |
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3
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Maximum Nominal Aggregate Size | 20 mm |
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4
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Minimum Cement Content (MORT&H 1700-3 A) | 310 kg/m3 |
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5
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Maximum Water Cement Ratio (MORT&H 1700-3 A) | 0.45 |
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6
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Workability (MORT&H 1700-4) | 50-75 mm (Slump) |
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7
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Exposure Condition | Normal |
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8
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Degree of Supervision | Good |
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9
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Type of Aggregate | Crushed Angular Aggregate |
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10
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Maximum Cement Content (MORT&H Cl. 1703.2) | 540 kg/m3 |
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11
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Chemical Admixture Type | Superplasticiser Confirming to IS-9103 |
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A-2
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Test Data for Materials | |
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1
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Cement Used | Coromandal King OPC 53 grade |
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2
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Sp. Gravity of Cement | 3.15 |
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3
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Sp. Gravity of Water | 1.00 |
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4
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Chemical Admixture | BASF Chemicals Company |
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5
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Sp. Gravity of 20 mm Aggregate | 2.884 |
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6
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Sp. Gravity of 10 mm Aggregate | 2.878 |
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7
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Sp. Gravity of Sand | 2.605 |
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8
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Water Absorption of 20 mm Aggregate | 0.97% |
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9
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Water Absorption of 10 mm Aggregate | 0.83% |
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10
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Water Absorption of Sand | 1.23% |
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11
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Free (Surface) Moisture of 20 mm Aggregate | nil |
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12
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Free (Surface) Moisture of 10 mm Aggregate | nil |
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13
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Free (Surface) Moisture of Sand | nil |
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14
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Sieve Analysis of Individual Coarse Aggregates | Separate Analysis Done |
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15
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Sieve Analysis of Combined Coarse Aggregates | Separate Analysis Done |
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15
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Sp. Gravity of Combined Coarse Aggregates | 2.882 |
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16
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Sieve Analysis of Fine Aggregates | Separate Analysis Done |
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A-3
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Target Strength for Mix Proportioning | |
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1
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Target Mean Strength (MORT&H 1700-5) | 42N/mm2 |
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2
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Characteristic Strength @ 28 days | 30N/mm2 |
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A-4
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Selection of Water Cement Ratio | |
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1
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Maximum Water Cement Ratio (MORT&H 1700-3 A) | 0.45 |
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2
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Adopted Water Cement Ratio | 0.42 |
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A-5
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Selection of Water Content | |
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1
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Maximum Water content (10262-table-2) | 186 Lit. |
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2
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Estimated Water content for 50-75 mm Slump | 160 Lit. |
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3
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Superplasticiser used | 0.5 % by wt. of cement |
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A-6
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Calculation of Cement Content | |
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1
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Water Cement Ratio | 0.42 |
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2
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Cement Content (160/0.42) | 380 kg/m3 |
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Which is greater then 310 kg/m3 | |
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A-7
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Proportion of Volume of Coarse Aggregate & Fine Aggregate Content | |
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1
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Vol. of C.A. as per table 3 of IS 10262 | 62.00% |
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2
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Adopted Vol. of Coarse Aggregate | 62.00% |
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Adopted Vol. of Fine Aggregate ( 1-0.62) | 38.00% |
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A-8
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Mix Calculations | |
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1
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Volume of Concrete in m3 | 1.00 |
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2
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Volume of Cement in m3 | 0.12 |
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(Mass of Cement) / (Sp. Gravity of Cement)x1000 | |
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3
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Volume of Water in m3 | 0.160 |
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(Mass of Water) / (Sp. Gravity of Water)x1000 | |
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4
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Volume of Admixture @ 0.5% in m3 | 0.00160 |
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(Mass of Admixture)/(Sp. Gravity of Admixture)x1000 | |
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5
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Volume of All in Aggregate in m3 | 0.718 |
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Sr. no. 1 – (Sr. no. 2+3+4) | |
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6
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Volume of Coarse Aggregate in m3 | 0.445 |
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Sr. no. 5 x 0.62 | |
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7
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Volume of Fine Aggregate in m3 | 0.273 |
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Sr. no. 5 x 0.38 | |
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A-9
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Mix Proportions for One Cum of Concrete (SSD Condition) | |
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1
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Mass of Cement in kg/m3 | 380 |
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2
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Mass of Water in kg/m3 | 160 |
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3
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Mass of Fine Aggregate in kg/m3 | 711 |
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4
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Mass of Coarse Aggregate in kg/m3 | 1283 |
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Mass of 20 mm in kg/m3 | 924 |
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Mass of 10 mm in kg/m3 | 359 |
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5
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Mass of Admixture in kg/m3 | 1.90 |
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6
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Water Cement Ratio | 0.42 |
Mix Design For M35 Grade Of Concrete
The mix design for M35 Grade Of Concrete for pile foundations provided here is for reference purpose only. Actual site conditions vary and thus this should be adjusted as per the location and other factors.
Grade of Concrete : M35
Characteristic Strength (Fck) : 35 Mpa
Standard Deviation : 1.91 Mpa*
Target Mean Strength : T.M.S.= Fck +1.65 x S.D.
(from I.S 456-2000) = 35+ 1.65×1.91
= 38.15 Mpa
Test Data For Material:
Aggregate Type : Crushed
Specific Gravity
Cement : 3.15
Coarse Aggregate : 2.67
Fine Aggregate : 2.62
Water Absorption:
Coarse Aggregate : 0.5%
Fine Aggregate : 1.0 %
MIX DESIGN
Take Sand content as percentage of total aggregates = 36%Select Water Cement Ratio = 0.43 for concrete grade M35
(From Fig 2. of I.S. 10262- 1982)
Select Water Content = 172 Kg
(From IS: 10262 for 20 mm nominal size of aggregates Maximum Water Content = 186 Kg/ M3 )
Hence, Cement Content= 172 / 0.43 = 400 Kg / M3
Formula for Mix Proportion of Fine and Coarse Aggregate:
1000(1-a0) = {(Cement Content / Sp. Gr. Of Cement) + Water Content +(Fa / Sp. Gr.* Pf )}
1000(1-a0) = {(Cement Content / Sp. Gr. Of Cement) + Water Content +Ca / Sp. Gr.* Pc )}
Where Ca = Coarse Aggregate Content
Fa = Fine Aggregate Content
Pf = Sand Content as percentage of total Aggregates
= 0.36
Pc = Coarse Aggregate Content as percentage of total Aggregates.
= 0.64
a0 = Percentage air content in concrete (As per IS :10262 for 20 mm nominal size of
aggregates air content is 2 %) = 0.02
Hence, 1000(1-0.02) = {(400 /3.15) + 172 +(Fa / 2.62 x 0.36)}
Fa = 642 Kg/ Cum
As the sand is of Zone II no adjustment is required for sand.
Sand Content = 642 Kg/ Cum
1000(1-0.02) = {(400 /3.15) + 172 +(Ca / 2.67 x 0.64)}
Hence, Ca = 1165 Kg/ Cum
From combined gradation of Coarse aggregates it has been found out that the proportion of 53:47 of 20 mm & 10 mm aggregates produces the best gradation as per IS: 383.
Hence, 20 mm Aggregates = 619 Kg
And 10 mm Aggregates = 546 Kg
To obtain slump in the range of 150-190 mm water reducing admixture brand SP430 from Fosroc with a dose of 0.3 % by weight of Cement shall be used.
Hence the Mix Proportion becomes:
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Cem
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W/C
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Water
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Sand
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20mm
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10mm
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Admix
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400
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0.43
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172
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635
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619
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564
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1.2
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1
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0.43
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1.6
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1.547
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1.36
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0.003
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Cement : Sand: Coarse Aggregates = 1 : 1.6 : 2.907
Wow, This is superb informatio.
ReplyDeletemix design of concrete from India
ReplyDeleteWow, This is superb post. nice information.
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