1. CONCRETE MIX-DESIGN ACI-211.1-91
Standard Practice for Selecting Proportions for Normal, Heavyweight, and Mass Concrete

2. Principles of Mix-Proportioning Design
PLACEABILITY
STRENGTH
DURABILITY
ECONOMY

3. PLACEABILITY CONSISTENCY WORKABILITY
Table A Recommened Slumps For Various Types of Construction
WORKABILITY

4. Table A1.5.3.1 -Recommended Slumps For Various Types of Construction
Type of Construction
Slump, mm
Maximum*
Minimum
Reinforced foundation wall and footing 75 25
Plain footings, caissons, and substructure walls
Beam and reinforced walls
100
Building Columns
Pavement and slabs
Mass concrete
* May be increased 25 mm for methods of consolidation other than vibration

5. STRENGTH & STIFFNESS Compressive Strength (f’c 28 day)
Flexural/ Tensile Strength
Elastic Modulus

6. Concrete Durability
“ Concrete must be able to endure those exposures that may deprive it of its serviceability ”
Freezing and thawing
Wetting and drying
Heating and cooling
Chemicals
Deicing Agents

7. Concrete Durability Spalling of concrete structure due to
Freeze-Thaw Deterioration

8. Concrete Durability Spalling of concrete structures due to Carbonation
structure due to
Sulfate Attack

9. Types of Gradations * Uniformly graded - Few points of contact
- Poor interlock (shape dependent)
- High permeability
* Well graded
- Good interlock
- Low permeability
* Gap graded
- Only limited sizes
- Good interlock
- Low permeability

10. Aggregate Size Definitions
% Passing
% Passing
100 99 89 72 65 48 36 22 15 9 4
100 90 72 65 48 36 22 15 9 4
Nominal Maximum Aggregate Size
one size larger than the first sieve to retain more than 10%
Maximum Aggregate Size
one size larger than nominal maximum size
For HMA pavements these are the definitions for gradations.

11. 3. Estimation of mixing water
Mix-Design Flowchart
1. Choice of Slump
TableA
2. Choice of max. size
of aggregate
3. Estimation of mixing water
TableA
No.
4.Selection of W/C ratio
TableA 9 5

12. 5. Calculation cement content (5) = (3) / (4)
6. Estimation of coarse aggregate
(6) = Volume of CA(TableA ) x dry-rodded unit mass
7.1 Mass Basis
Wt. of sand = wt. of conc.(A ) –
total wt. of all materials
7. Estimation of fine aggregate
7.2 Absolute volume Basis
Vol. of sand= Vol. of concrete - (Vw+VC+VCA+Vair) 8

13. 8. Adjusted weight from moisture of sand and coarse aggregate7
8. Adjusted weight from moisture of
sand and coarse aggregate
9. Trial batch
Check properties of fresh and
Harden concrete
No. 2
Yes
Stop

14. Example 1.
Concrete is required for portion of structure that will be below ground level in a location where it will not be exposed to severe weathering or sulfate attack. Structural considerations require it to have an average 28-day compressive strength of 24 MPa with slump of 75 to 100 mm. the materials properties are as follows
nominal max. size of coarse aggregate = 37.5 mm.
dry rodded mass of 1,600 kg/m3
cement type I : S.G. = 3.15
bulk specific gravity of coarse aggregate = 2.68, absorption = 0.5%
bulk specific gravity of sand = 2.64, absorption = 0.7%, F.M. = 2.8
Determine the quantities ingredients per m3 of concrete.

15. Example 1. Step 1 From A1.5.3.1 Slump = 75-100 mm.
Step 2 Given max size = 37.5 mm.
Step 3 From A , estimate mixing water = 181 kg/m3
Step 4 From A (a) W/C = 0.62
Step 5 Cement = 181/0.62 = 292 kg./m3
Step 6. From A and fineness modulus (FM) of sand = 2.8 and max. size of coarse aggregate = 37.5 mm, Volume of CA = 0.71
dry mass of CA = 1600 x 0.71 = 1,136 kg.
Step 7.1 Mass Basis
From A the mass of cubic meter of concrete = 2410 kg
Water = 181 kg
Cement = 292 kg
CA = 1136 kg
Total = 1609 kg, hence mass of sand = = 801 kg.

16. Example 1. Step 7.2 Absolute Volume Basis
V of water = 181/1000 = m3
V of cement = 292/(3.15*1000) = m3
V of CA = 1136/(2.68 x 1000) = m3
V of entrapped air = 0.01 x 1 = m3
Total solid volume of ingredients except fine aggregate = m3
V of sand = 1.0 – = m3
Required weight of dry sand = x 2.64 x 1000 = 771 kg

17. Example 1.
Step 8. Adjusted weight from moisture of sand and coarse aggregate
= 5.3 %
0.7 %
SAND
absorption
surface water CA
0.5 %
= 1.5 %
CA wet = 1.02 x 1136 = 1159 kg.
Sand wet = 1.06 x 771 = 849 kg.
Add water =181-(0.015 x 1136 ) – (0.053 x 771) = 122 kg.

18. Example 1.
The estimate batch masses for a cubic meter of concrete are :
Added water = 122 kg
Cement = 292 kg
Wet coarse aggregate = 1159 kg
Wet sand = 849 kg
Total = 2422 kg