Mix Design With Superplasticizers
Posted in Mix Design, Research Papers  Email This Post By
Er. Kaushal Kishore ,
Materials Engineer, Roorkee
INTRODUCTION
Superplasticizers belongs to a class of water reducer chemically different from the normal water reducers and capable of reducing water content by about 30%. The Superplasticizers are broadly classified into four groups: sulfonated melamine formaldehyde condensate (SMF), sulphonated naphthalene formaldehyde condensate (SNF), modified lignosulphonate (MLS) and others including sulphonic acid ester, polyacrylates, polystryrene sulphonates, etc. The benefits obtained by Superplasticizers in the reduction of water in the concrete mixes are best illustrated by the following examples.
MIX DESIGN DETAILS
1  Grad of Concrete  :  M40 
2  Cement  :  Three mixes are to be designed 
MIXA
With PPC (Flyash based) conforming to IS:1489partI1991. 7 days strength 38.5 N/mm^{2}. Specific Gravity : 3.00 

MIXB
With OPC43 Grade conforming to IS: 81121989. 7 days strength 40.7 n/mm^{2}. Specific Gravity : 3.15 

MIXC
With OPC of MixB and Fly ash conforming to IS:3812 (PartI)2003 Specific Gravity : 2.25 

Note: Requirements of all the three mixes are the same. Fine Aggregate, Coarse Aggregate and normal Super plasticizer are the same for all the three mixes.  
3  Fly ash replacement  :  30% 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 ZoneII as per IS:3831970 
6  Minimum cement content  :  360 kg/m^{3} including Fly ash 
7  Maximum free W/C Ratio  :  0.40 
8  Workability  :  50 mm slump 
9  Exposure condition  :  Extreme for RCC work 
10  Method of placing  :  Site mixing 
11  Degree of supervision  :  Good 
12  Maximum of cement content (Fly ash not included)  :  450 kg/m^{3} 
13  Chemical admixture  :  Super plasticizer conforming to IS:91031999. With the given requirements and materials, the manufacturer of Normal Super plasticizer recommends dosages of 20 gm per kg of OPC, which will reduce 28% of water without loss of workability. For fly ash included cement dosages will be required to be adjusted by experience/ trials. 
TEST DATA FOR MATERIALS
1. The grading of fine aggregate, 10 and 20 mm aggregates are as given in Table. 1. Fine aggregate is of zoneII as per IS:3831970. 10 and 20 mm crushed aggregate grading are single sized as per IS: 3831970.
2. Properties of aggregates
Tests 
Fine aggregate 
10 mm aggregate 
40 mm aggregate 
Specific Gravity 
2.65 
2.65 
2.65 
Water Absorption % 
0.8 
0.5 
0.5 
3. Target strength for all A, B and C mixes
fck = fck + 1.65 x S
40 + 1.65 x 5
= 48.3 N/mm^{2} at 28 days age
4. For Mix A and B free W/C ratio with crushed aggregate and required target strength of 48.3 N/mm^{2} at 28 days from Fig. 1 Curve D found to be 0.4 Taking into the consideration of water in admixture,let it be 0.39. This is lower than specified maximum W/C ratio value of 0.4
Note:
In absence of cement strength, but cement conforming to IS Codes, assume from Fig. 1 and Fig. 2.
Curve A and B – OPC 33 Grade
Curve C and D – OPC 43 Grade
Curve E and F – OPC 53 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 MIXA WITH PPC
a) Free W/C ratio for the target strength of 48.3 N/mm^{2} as worked out is 0.39.
b) Free water for 50 mm slump from Table 2 for 20 mm maximum size of aggregate.
2/3*180 + 1/3*210
= 190 kg/m^{3}
From trials also it is found that Normal Super plasticizer at a dosages of 21gm/kg of cement may reduce 28% water without loss of workability
Then water = 190 – (190 x 0.28) = 136.8 kg/m^{3}
for trials say 137 kg/m^{3}
c) PPC = 137/0.39 = 351 kg/m^{3} This is lower than minimum requirement of 360 kg/m^{3}. Then take 360 kg/m^{3}.
Then W/C = 137/360 = 0.38
d) Formula for calculation of fresh concrete weight in kg/m^{3}
U_{m}= 10 x G_{a} (100 – A) + CM(1 – G_{a}/G_{c}) – WM (G_{a} – 1)
Where,
U_{m} = Wight of fresh concrete kg/m^{3}
G_{a} = Weighted average specific gravity of combined fine
and coarse aggregate bulk, SSD
G_{c} = 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% for 40 mm maximum size of aggregate, 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.
W_{m} = Mixing water required in kg/m^{3}
C_{m} = Cement required, kg/m^{3}
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.
U_{m} =10 x G_{a} (100 – A) + C_{m} (1 – G_{a}/G_{c}) – W_{m} (G_{a} – 1)
=10 x 2.65 (100 – 1.5) + 360(1 2.65/3.00) – 137 (2.65 1)
2426 kg/m^{3}
e)Aggregates = 2426 – 360 – 137 = 1929 kg/m^{3}
f) Fine aggregate = From Table 3 for zoneII Fine aggregate and
20 mm maximum size of aggregate, W/C ratio = 0.39, 50 mm slump found to be for trial 33%.
Fine aggregate = 1929 x 0.33 = 637 kg/m^{3}
Coarse aggregate = 1929 – 637 = 1292 kg/m^{3}
10 and 20 mm aggregate are single sized as per IS: 3831970. Let they be combined in the ratio of 1.2:1.8 to get 20 mm graded aggregate as per IS: 3831970
10 mm aggregate = 517 kg/m^{3}
20 mm aggregate = 775 kg/m^{3}
g) Thus for M40 Grade of concrete quantity of materials per cu.m.
of concrete on the basis of saturated and surface dry aggregates:
Water=137 kg/m^{3}
PPC = 360 kg/m^{3}
Fine Aggregate (sand) = 637 kg/m^{3}
10 mm Aggregate = 517 kg/m^{3}
20 mm Aggregate = 775 kg/m^{3}
Normal Super Plasticizer = 7.560 kg/m^{3}
MIX B WITH OPC
a) Water = 190 – (190 x 0.28) = 136.8 kg/m^{3} say 137 kg/m^{3}
b) OPC = 137/0.39 = 351 kg/m^{3}
Minimum content specified = 360 kg/m^{3}
Then take 360 kg/m^{3}
c) Density:
10 x 2.65 (100 – 1.5) + 360 (1 – 2.65/3.15) – 137 (2.65 – 1)
= 2442 kg/m^{3}
d) Total Aggregates = 2442 – 137 – 360 = 1945 kg/m^{3}
Fine Aggregate = 1945 x 0.33 = 642 kg/m^{3}
Coarse aggregate = 1945 – 642 = 1303 kg/m^{3}
10 mm Aggregate = 1303×1.2/3 = 521 kg/m^{3}
20 mm Aggregate = 1303×1.8/3 = 782 kg/m^{3}
e) Thus for M40 Grade of concrete quantity of materials per cu.m of concrete on the basis of SSD aggregates are given below:
Water = 137 kg/m^{3}
PPC = 360 kg/m^{3}
Fine Aggregate (sand) = 642 kg/m^{3}
10 mm Aggregate = 521 kg/m^{3}
20 mm Aggregate = 782 kg/m^{3}
Normal Super Plasticizer = 7.2 kg/m^{3}
MIX. C WITH OPC + FLYASH
With the given set of materials increase in cementitious materials = 12%
Total cementitious materials = 360 x 1.12 = 403 kg/m^{3}
Materials 
Weight (kg/m^{3}) 
Volume (m^{3}) 
OPC = 403 x 0.70 
282/3150 
0.0895 
Flyash = 403 x 0.30 
121/2250 
0.0538 
Free Water = 137 x 0.95 
130/1000 
0.13 
Normal Super Plasticizer = 8.2kg 
8.2/1150 
0.0071 
Air = 1.5% 

0.015 
Total 
0.2954 

Total Aggregates = 1 – 0.2954 

0.7046 

1.00 

Coarse Aggregate 
1303/2650 
0.4917 
Fine Aggregate = 0.7046 – 0.4917 = 0.2129
= 0.2129 x 2650 = 564 kg
Note:
1. Specific gravity of Normal Superplasticizer = 1.15
2. Addition of Flyash reduces 5% of water demand.
M40 Grade of concrete 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/m^{3} 
137 
137 
130 
PPC kg/m^{3} 
360 
— 
— 
OPC kg/m^{3} 
— 
360 
282 
Flyash kg/m^{3} 
— 
— 
121 
Fine Agg. kg/m^{3} 
637 
642 
564 
10mm Agg. kg/m^{3} 
517 
521 
521 
20 mm Agg. kg/m^{3} 
775 
782 
782 
Normal Super plasticizer kg/m^{3} 
7.560 
7.2 
8.2 
W/Cementations ratio 
0.38 
0.38 
0.323 
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.
Table. 1: Grading of Aggregates
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 
85 
4 
4.75 mm 
99 
5 
0 
2.36 mm 
88 
0 

1.18 mm 
74 


600 Micron 
43 


300 Micron 
24 


150 Micron 
6 


Table. 2: Approximate freewater content (kg/m3) required to give various levels of workability for nonairentrained (with normal entrapped air) concrete.
Maximum size of aggregate (mm)  Type of aggregate  Slump (mm) Degree of workability 
— vary low 
2575 … Low 
50100 … Medium 
100180 … High 
10 
Uncrushed Crushed 
150 180 
205 235 
220 250 
240 265 

20 
Uncrushed Crushed 
140 170 
180 210 
195 225 
210 245 

40 
Uncrushed Crushed 
120 155 
160 190 
175 205 
190 220 
Note: When coarse and fine aggregate of different types are used, the free water content is estimated by the expression.
2/3W_{f}+1/3W_{c}
Where,
W_{f}=Free water content appropriate to type of fine
Aggregate and W_{c}=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 with different workability.
Table. 4: Proportion of fine aggregate (percent) with 40 mm maximum sizes of Aggregates and with different workability.
Grading Zone of F.A 
W/C Ratio 
40 mm aggregate Workability 

VL 
L 
M 
H 

I 
0.3 
2733 
2935 
3339 
3846 
0.4 
2935 
3138 
3542 
4149 

0.5 
3138 
3341 
3744 
4352 

0.6 
3341 
3643 
3947 
4554 

0.7 
3644 
3846 
4250 
4757 

II 
0.3 
2227 
2329 
2733 
3128 
0.4 
2429 
2531 
2835 
3241 

0.5 
2531 
2733 
3037 
3443 

0.6 
2733 
2936 
3239 
3645 

0.7 
2936 
3138 
3442 
3847 

III 
0.3 
1822 
2023 
2227 
2631 
0.4 
2024 
2125 
2428 
2732 

0.5 
2125 
2327 
2530 
2934 

0.6 
2327 
2429 
2732 
3036 

0.7 
2429 
2631 
2934 
3236 

IV 
0.3 
1618 
1820 
1922 
2226 
0.4 
1720 
1921 
2024 
2427 

0.5 
1821 
2023 
2225 
2529 

0.6 
2023 
2224 
2327 
2630 

0.7 
2124 
2326 
2529 
2832 
VL = Very low workability.
L = Low workability – slump 2575 mm
M = medium workability – slump 50100 mm
H = High workability slump 100180 mm
Figures From Experimental Data
Click on the picture to zoom it.
REFERENCES
1 IS : 3831970 Specifications for coarse and fine aggregates from natural sources for concrete (second revision) BIS, New Delhi
2 IS: 4562000Code of practice for plain and reinforced concrete (fourth revision), BIS, New Delhi
3 IS: 91031999 Specification for admixtures for concrete (first revision) BIS, New Delhi
4 IS: 81121989 Specifications for 43 Grade ordinary portland cement (first revision) BIS, New Delhi
5 IS: 2386 (PartIII) 1963 method of test for aggregate for concrete. Specific gravity, density, voids, absorption and bulking, BIS, New Delhi
6 IS: 3812 (PartI) 2003 Specification for pulverized fuel ash: PartI for use as pozzolana in cement, cement mortar and concrete (second revision) BIS, New Delhi
7 IS: 1489PartI 1991 Specifications for portland pozzolana cement (PartI) Flyash based. (Third revision), BIS, New Delhi
8 Kishore Kaushal, “Design of Concrete Mixes with HighStrength Ordinary Portland Cement”. The Indian Concrete Journal, April, 1978, PP. 103104
9 Kishore Kaushal, “Concrete Mix Design”. A manual published for Structural Engineering Studies, Civil Engineering Department, University of Roorkee, 1986.
10 Kishore Kaushal, “Concrete Mix Design Based on Flexural Strength for AirEntrained Concrete”, Proceeding of 13th Conference on our World in Concrete and Structures, 2526, August, 1988, Singapore.
11 Kishore Kaushal, “Concrete Mix Design”, Indian Concrete Institute Bulletin September, 1988, pp. 2740 and ICI Bulletin December, 1988, pp. 2131.
12 Kishore Kaushal, “Method of Concrete Mix Design Based on Flexural Strength”, Proceeding of the International Conference on Road and Road Transport Problems ICORT, 1215 December, 1988, New Delhi, pp. 296305.
13 Kishore Kaushal, “Mix Design Based on Flexural Strength of AirEntrained Concrete”. The Indian Concrete Journal, February, 1989, pp. 9397.
14 Kishore Kaushal, “Concrete Mix Design”, VIII All India Builders Convention 2931, January, 1989, Hyderabad, organized by Builders Association of India, Proceeding Volume pp. 213260.
15 Kishore Kaushal, “Concrete Mix Design Containing Chemical Admixtures”, Journal of the National Building Organization, April, 1990, pp. 112.
16 Kishore Kaushal, “Concrete Mix Design for Road Bridges”, INDIAN HIGHWAYS, Vol. 19, No. 11, November, 1991, pp. 3137
17 Kishore Kaushal, “A Concrete Design”, Indian Architect and Builder, August, 1991, pp. 5456
18 Kishore Kaushal, “ Mix Design for Pumped Concrete”, Journal of Central Board of Irrigation and Power, Vol. 49, No.2, April, 1992, pp. 8192
19 Kishore Kaushal, “Concrete Mix Design with Fly Ash”, Indian Construction, January, 1995, pp. 1617
20 Kishore Kaushal, “HighStrength Concrete”, Civil Engineering and Construction Review, March, 1995, pp. 5761.
21 Kishore Kaushal, “HighStrength Concrete”, Bulletin of Indian Concrete Institute No. 51, AprilJune, 1995, pp. 2931
22 Kishore Kaushal, “Mix Design of PolymerModified Mortars and Concrete”, New Building Materials & Construction, January, 1996, pp. 1923.
23 Kishore Kaushal, “Concrete Mix Design Simplified”, Indian Concrete Institute Bulletin No. 56, JulySeptember, 1996, pp. 2530.
24 Kishore Kaushal, “Concrete Mix Design”, A Manual Published by M/S Roffe Construction Chemicals Pvt. Ltd., Mumbai, pp. 136
25 Kishore Kaushal, “Concrete Mix Design with Fly Ash & Superplasticizer”, ICI Bulletin No. 59, AprilJune 1997, pp. 2930
26 Kishore Kaushal. “Mix Design for Pumped Concrete”, CE & CR October, 2006, pp. 4450.
We are thankful to Er. Kaushal Kishore, Materials Engineer, Roorkee for submitting this very useful research to us so that other civil engineering students can take guidance from it.
thanks Mr Kaushal, this is really very useful for my project work
Glad to see a mix design with superplasticizers. I am working in Dubai from past 5 years and this data would help me work better
thanks Mr kaushal for my study,would you like to help me for the preparation of IES EXAM
My branch is civil ,i am in 2nd yr,
thanks Mr Kaushal, this is really very useful for my project work of PQC
sir im civil supervisor please mail me concerte M10 to M50 Mix Design in cft.
Thanks Sir. I am brick manufacturer. Can u kindly help me in getting a design mix for fly ash bricks. I am using right now ash, sand and cement to produce bricks. but i want to add super plasticizers un order to reduce the water consumption and produce quality bricks.
Regds
Radharaman