1. CEMENT CONCRETE MIX DESIGN*
CEMENT CONCRETE MIX DESIGN by
Ajit kumar
CLASS-D2 C3
Roll No 1

2. *
Cement Concrete Mix Design means, determination of the proportion of the concrete ingredients i.e. Cement, Water, Fine Aggregate,Coarse Aggregate which would produce concrete possessing specified properties such as workability, strength and durability with maximum overall economy. 2

3. Methods of Concrete Mix Design*
Methods of Concrete Mix Design
I.S. Method
British Method
A.C.I. Method etc. 3

4. These Methods are based on two basic assumptions*
These Methods are based on two basic assumptions
Compressive Strength of Concrete is governed by its Water-Cement Ratio
Workability of Concrete is governed by its Water Content 4

5. Data required for concrete mix design*
Data required for concrete mix design
Grade of Concrete
Eg: RCC-M30-A20
Slump required in mm
Eg: 25 – 75 mm
Degree of Site Control
Eg: Good
Type of Exposure
Eg: Moderate
Grade of Cement
Eg: OPC 43 Grade 5

6. your text Placing Conditions Degree of Workability Slump (mm) 1 2 3*
your text
Placing Conditions
Degree of Workability
Slump (mm) 1 2 3
Blinding Concrete;
Shallow Sections;
Pavements using pavers
Very Low
See 7.1.1
Mass Concrete;
Lightly reinforced sections in Slabs, Beams, Walls, Columns; Floors;
Hand placed Pavements;
Canal lining; Strip Footings
Low
25-75
Heavily reinforced sections in Slabs,
Beams, Walls, Columns;
Slip form work; Pumped Concrete.
Medium
50-100
Trench fill; In-Situ Piling; Tremie Concrete
High 6

7. your text Good Site control having proper storage of cement;*
your text
Good
Site control having proper storage of cement;
weigh batching of all materials;
Controlled addition of water,
regular checking of all materials,
aggregate grading and moisture content;
And periodical checking of workability and strength.
Fair
Site control having deviation from the above. 7

8. STEPS INVOLVED IN CONCRETE MIX DESIGN*
STEPS INVOLVED IN CONCRETE MIX DESIGN
Step I:- Determine the physical properties of
concrete ingredients.
CEMENT (OPC 43 Grade)
1.Grade designation -m40
2.type of cement opc 43 grade
3.maximum nominal size of aggregate -20mm
4.minimum cement content kg/m3
5.Maximum w/c ratio
6.workability mm (slump)
7.exposure condition -severe
8.Method of concrete placing - pumping
9.Degree of supervision -good
10.Type of aggregate -crushed angular aggregate
11.Maximum cement content kg/m3
12.Chemical admixture type - superplasticizers 8

9. Test data for materials:- 1.Specific gravity of cement-3.15*
Test data for materials: Specific gravity of cement-3.15
2.sp. gr. Of course aggregate sp. gr. Of fine aggregate-2.74
4.Water absorption by ca-0.5 %
5.Water absorption by fa-1%

10. Step II:- Compute Target Mean Compressive Strength:*
Step II:- Compute Target Mean Compressive Strength:
Fck = fck + t * S
Fck = Target Mean Compressive Strength at 28 days in
N/Sq.mm
fck = Characteristic Compressive Strength at 28 days in
S = Standard Deviation in N/Sq.mm
t = A Statistic, depending on accepeted proportion of
low results.
= for 1 in 20 accepted proportion of low
results 10

11. Accepted proportion of low results*
Values of t
Accepted proportion of low results t
1 in 5, %
0.84
1 in 10, 10%
1.28
1 in 15, %
1.50
1 in 20, 5%
1.65
1in 40, %
1.86
1 in 100, 1%
2.33 11

12. Assumed Standard Deviation*
Assumed Standard Deviation
(Table 8, IS: )
Grade of Concrete
Assumed Standard Deviation
(N/Sq.mm)
Good Site Control
Fair Site Control
M10, M15
3.5
4.5
M20, M25
4.0
5.0
M30, M35
M,40,M45
M50
6.0 12

13. Step III:- Select the Water-Cement ratio of trial mix from experience*
Step III:- Select the Water-Cement ratio of trial mix from
experience S.
No.
Concrete
Grade
Minimum expected W/C 1
M10
0.9 2
M15
0.7 3
M20
0.55 4
M25
0.50 5
M30
0.45 6
M35
0.40 7
M40
0.35 8
M45
0.30 13

14. Maximum size of Aggregate Water Content per cubic metre of concrete*
Step IV:- Select the water content per cubic metre of
concrete from table2 of I.S:
Maximum size of Aggregate
(mm)
Water Content per cubic metre of concrete
(Kg) 10
208 20
186 40
165 14

15. Maximum Size of Aggregate*
Approximate water content (Kg)
per cubic metre of concrete
(Table 32, SP: )
Slump
(mm)
Maximum Size of Aggregate 10 20 40
30-50
205
185
160
80-100
225
200
175
240
210 15

16. Volume of Coarse Aggregate per Unit Volume of Total Aggregate*
Volume of Coarse Aggregate per
Unit Volume of Total Aggregate
(Table 3, IS: )
Maximum Size of Aggregate
(mm)
Volume of Coarse Aggregate per Unit Volume of Total Aggregate
Zone IV
Zone III
Zone II
Zone I 10
0.50
0.48
0.46
0.44 20
0.66
0.64
0.62
0.60 40
0.75
0.73
0.71
0.69 16

17. Cement = ------------- Water*
= 140 /. 35=400kg/m3
W/C Ratio
Cement =
Water
Step V:- Compute the quantity of cement as follows. 17

18. *
Step VI:- Then we find the quantities of Fine & Coarse aggregate by absolute volume method.
V = (W+C/Sc+(1/p) * (fa/Sfa)) * (1/1000) (Eq.1)
and
V = (W+C/Sc+(1/(1-p)) * (ca/Sca)) * (1/1000) (Eq.2)
Where
V = Absolute volume of fresh concrete = 1 m3
W = Mass of Water (Kg) per m3 of concrete
C = Mass of Cement (Kg) per m3 of
concrete
p = Percentage of fine aggregate.
fa = Mass of fine aggregate
ca = Mass of coarse aggregate
Sc = Specific gravity of cement.
Sfa = Specific gravity of fine aggregate.
Sca = Specific gravity of coarse aggregate. 18

19. Substituting all the values in Eq(1), we get *
Substituting all the values in Eq(1), we get
Mass of fine aggregate (fa ) = 896 kg 19

20. Substituting all the values in Eq(2), we get *
Substituting all the values in Eq(2), we get
Mass of course aggregate (ca) = 1140 kg 20

21. So the mix proportion works out to be W : C : fa : ca *
So the mix proportion works out to be
W : C : fa : ca
= 140 : 400 : 896: 1140
= : 0.5 : 2.24 : 2.80
This mix will be considered as Trial Mix 21

22. *
Thank you!