CIVIL ENGG.

1. DEPARTMENT OF CIVIL ENGINEERING, REC BIJNOR
Rajkiya Engineering College, Chandpur,
Bijnor
Mix design of Concrete: IS method

2. General Outline
• The IS 10262 method
• Example
DEPARTMENT OF CIVIL ENGINEERING, REC BIJNOR

3. Factors Influencing Choice of Mix Design
• According to IS 456:2000 and IS 1343:1980 the important
influencing the design of concrete mix are
 Gradeof Concrete
 Typeof Cement
 Maximum nominal Size ofAggregate
 Gradingof Combined aggregate
 MaximumWater/CementRatio
 Workability
 Durability
 Quality Control.

4. IS METHOD
Step 1: f t =f ck + 1.65
The standard deviations are:
M10-M15: 3.5 MPa
M20-M25: 4.0 MPa
M30-M50: 5.0 MPa
DETERMINE FROM SITE DATA, 30 CUBES
DEPARTMENT OF CIVIL ENGINEERING, REC BIJNOR

5. IS METHOD
DEPARTMENT OF CIVIL ENGINEERING, REC BIJNOR
Step 2 : selection of w/c from curves

6. IS METHOD
DEPARTMENT OF CIVIL ENGINEERING, REC BIJNOR
Step 2 :
selection
of w/c
from
curves

7. Step 3: Estimate water content & sand
contents for concrete grades up to M35/
above M35
IS METHOD
DEPARTMENT OF CIVIL ENGINEERING, REC BIJNOR
M.S.A(mm) Water kg/m3 Sand
Proportion=Fagg
Vol (%of Total)
10 208 40
20 186 35
40 165 30

8. Step 3: Estimate water content & sand
contents for concrete grades up to M35/
above M35
IS METHOD
M.S.A (mm) Water
kg/m3
p=Fagg vol
(%of Total)
10 200 28
20 180 25
DEPARTMENT OF CIVIL ENGINEERING, REC BIJNOR

9. IS METHOD
Step 3: Estimate water content & sand
contents for concrete grades up to M35/
above M35
The Tables are for:
Crushed CA
Fine aggregate Zone II
w/c =0.6(up to M35) & 0.35 (>M35)
Compaction factor =0.8
DEPARTMENT OF CIVIL ENGINEERING, REC BIJNOR

10. Step 3: Estimate water content & sand
contents for concrete grades up to M35/
above M35 (Adjustments)
IS METHOD
Condition Adjusments
Δwater Δp (%)
Fine Sand ZoneI,III,IV 0 + 1.5 percent for zone I
-1.5 percent for zone III
-3.0 for zone IV
CF(±) 0.1 3%(±) 0
w/c (±) 0.05 0 ±1%
Rounded agg 15kg/m3 -7%
DEPARTMENT OF CIVIL ENGINEERING, REC BIJNOR

11. Step 4: Calculate cement content, Aggregate
contents,
w/c*= Min (w/ccurve, w/cdurability) .
 C=Max(W/ w/c*, Cdurability).
IS METHOD
1
1000
 
C SFagg 
Fagg
V  W 
S
1000
1
C

1
p
1

C SCagg 
Cagg
(1 p)
C
V  W 
S

DEPARTMENT OF CIVIL ENGINEERING, REC BIJNOR

12. V=1-air content
IS METHOD
M.S.A (mm) Air content
(%)
10 3.0
20 2.0
40 1.0
DEPARTMENT OF CIVIL ENGINEERING, REC BIJNOR

13. IS METHOD (Example)
DEPARTMENT OF CIVIL ENGINEERING, REC BIJNOR
M25 concrete
Cement 43 grade
Moderate exposure
sand Zone III
Compaction factor 0.9
20 mm m.s.a rounded aggregate

14. IS METHOD (Example)
Step 1: f t =f ck + 1.65
=4
Grade SD TMS
25 4 31.6
f t= 32 MPa
DEPARTMENT OF CIVIL ENGINEERING, REC BIJNOR

15. IS METHOD
Step 2 :
selection
of w/c
from
curves
w/c =0.43
DEPARTMENT OF CIVIL ENGINEERING, REC BIJNOR

16. IS requirements (RCC)
Exposure Min Cement Max w/c Min Grade
Mild 300 0.55 M 20
Moderate 300 0.50 M 25
Severe 320 0.45 M 30
Very severe 340 0.45 M 35
Extreme 360 0.40 M40
DEPARTMENT OF CIVIL ENGINEERING, REC BIJNOR
Step 2: w/c*=0.43,

17. Step 3: Estimate water content & sand
contents for concrete grades up to M35/
above M35
IS METHOD
m.s.a (mm) Water
kg/m3
p=Fagg(%of
Total)
10 208 40
20 186 35
40 165 30
DEPARTMENT OF CIVIL ENGINEERING, REC BIJNOR

18. Step 3: Adjustments
water =(0.9-0.8)/0.1×0.03*186-15 = -9.2 kg/m3
 p (%)=-1.5+(0.43-0.6)×0.01/0.05-7 = -11.9
IS METHOD
Condition Adjusments
Water p (%)
Sand ZoneI,III,IV 0 -1.5% /zone(+ for I)
CF(±) 0.1 3%(±) 0
w/c (±) 0.05 0 ±1%
Rounded agg -15 -7
DEPARTMENT OF CIVIL ENGINEERING, REC BIJNOR

19. IS METHOD
• Step 4:
w/c*= Min (0.43, 0.50)=0.43 . W=186-9.2177kg/m3
 C=Max(177/ 0.43, 300). =411.6412 kg/m3
p= 35-11.9=23.1 Fagg=419.25 kg/m3
1
3.15 0.231 2.7 1000

412

1(1 0.02) 

177
Fagg

1412 1

2.6 10003.15 (10.231)
 
0.98  
177
Cagg
Cagg= 1344.0kg/m3
DEPARTMENT OF CIVIL ENGINEERING, REC BIJNOR

20. IS METHOD
 W=186-9.2177kg/m3
Cement =Max(177/ 0.43). =411.6412 kg/m3
Fagg=419.25 kg/m3
Cagg= 1344.0kg/m3
Total= 2352 kg/m3
DEPARTMENT OF CIVIL ENGINEERING, REC BIJNOR

21. IS METHOD
Actual water to be added =177-water (present –
absorption) in aggregate in kg/m3
Actual quantity of aggregate in the mix
shall be Aggregate content + extra due to
(moisture content- absorption)
 Trial mix and final adjustment
DEPARTMENT OF CIVIL ENGINEERING, REC BIJNOR

22. THANK YOU FOR
HEARING
DEPARTMENT OF CIVIL ENGINEERING, REC BIJNOR