2. INTRODUCTION 1
AMERICAN CONCRETE INSTITUTE (ACI) METHOD 4
GENERAL 5
LIMITATION ACI METHOD 5
REQUIRED PARAMETERS OF INGREDIENTS 5
EQUIPMENT AND APPARATUS 6
DESIGN GUIDE LINE 7
SUMMARY OF DESIGN PROCEDURE 12
MIX DESIGN DATA SHEET 13
DESIGN STEPS 14
COMPRESSIVE STRENGTH TEST OF SAMPLE 17
GRAPHICAL DETERMINATION OF REQUIRED
W/C RATIO 18
HIGH STRENGTH MIX METHOD 19
GENERAL 20
FEATURE OF DESIGN 20
LIMITATION OF HIGH STRENGTH DESIGN 21
REQUIRED PARAMETERS OF INGREDIENTS 22
DESIGN PROCEDURE 23
EQUIPMENT AND APPARATUS 24
MIX DESIGN DATA SHEET 27
DESIGN STEPS 28
Contents
2
3. INTRODUCTION
1. American Concrete Institute (ACI)
2. High Strength Mix
Cement concrete is an artificial rock which can be made of required
size, shape, and strength for the structure in construction work. It is the
most widely used construction material and is very hard to find its
substitution . Technologists may select this construction material as their
requirement such as strength, permanance, durability, impermeability, fire-
resistance, abrasion resintance etc. Regarding these required properties of
concrete, it is very important to determine the proportion as well as quality
of its constituents. Determining process of selecting suitable ingredients,
its proportion, producing minimum strength and durability as economically
as possible is called mix design.
In Nepal, still we adopt the arbitrary proportional ratio method in
many organizations of HMG departments, municipalities, private buildings
and other small scaled projects. But most of the large scaled foreign aid
projects can not ignore the necessity of mix design of the concrete for
precise supervision. The arbitrary proportinal method may always not
govern the true proportion of ingredients and cause segregation, bleeding,
uneconomic and weaker or over strength. People are not conscious to hire
Basic concept of mix design prevails on the relationship between
two essential ingredients i.e. aggregates and paste. Paste is not termed as
solution of cement in water, but the suspension of cement particles. Hence
the degree of dilution of paste may affect workability and strength of the
concrete. The more dilute the paste, the greater the spacing between
cement particles and thus the weaker will be ultimate paste structure. It is
therefore helpful to consider more closely the structure of the paste. It is
important that as little paste as possible should be used and here lies the
importance of grading of aggregates. Excess of paste cause high cost,
greater shrinkage, greater susceptibility to percolation of water and
therefore attack by aggressive waters and weathering action. This is
achieved by minimising the voids by well gradation.
There are several methods of mix design to adopt, but here we
describe only two of them in detail which are more effective and viable in
the contest of Nepal. Most of the renowned projects and agencies of Nepal
have been adopting these two mix-design methods widely as per their
requisites of the concrete materials. These methods are -
3
4. 1. Cement:
a) Portland cement, of possibly 53 grade
b) Specific gravity 3.15
2. Fine Aggregate
a) Required size and well-graded and washed.
b) Saturated surface dry condition (SSD)
c) Very less weathering, alluvial (glacier) blueish grey:
Specific gravity 2.65 to 2.67 Absorption 1.0%
d) Less weathering, alluvial deposit (perennial river), yellowish grey:
Specific gravity 2.62 to 2.64 Absorption 1.5%
e) Less weathering, alluvial deposit (stream), pale yellow:
Specific gravity 2.59 to 2.61 Absorption 2.0%
f) Washed crushed rock:
Specific gravity 2.62 to 2.65 Absorption 1.5%
g) Fineness modulus (FM)
coarser 3.1, moderate 2.9, fine 2.6, very fine 2.3
3. coarse Aggregate
a) Required size and well-graded and washed.
b) Saturated surface dry condition (SSD)
c) Alluvial / glacier (fresh deposit):
Specific gravity 2.67 to 2.72 Absorption 0.3%
d) Alluvial / common perennial river (fresh deposit):
Specific gravity 2.62 to 2.66 Absorption 0.5%
e) Alluvial (loose conglomerate):
Specific gravity 2.62 to 2.65 Absorption 0.7%
f) Washed crushed rock (stream),
Specific gravity 2.62 to 2.65 Absorption 0.7%
a technician to conduct the supervision and rely on a head mason who will
be contractor of their private construction. In Terai region of Nepal, most of
these masons have tendency of using more sand with large size coarse
aggregate and less sand with small size aggregate which is absolutely
wrong approach . Due this reason, people find their construction defective
after all.
Regarding these common problems all over the country, it is highly
necessary to follow the technical way of construction wheather it's small or
huge construction. Possibly, it is needed to conduct the test of concrete
materials to obtain true design parameters. Otherwise adopt in design
these parameters for concrete materials, if conducting the test is not
possible. These parameters are here tabulated below according to practice
and records.
4
5. g) Compacted density (Kg/m3
):
Aggregate
Sp.gr. 2.62 - 2.65 2.66 - 2.69
50 mm
16001600
17001750 1800
1650 1400
Crushed rock:
1650 1650
1550
From the above statement, a technical person can easily decide the
nearest true properties of concrete material according to its possession
regarding location, appearance etc. After conforming these data
tentatively, here we can proceed the mix design calculation as per our
requirements. It may give more accurate proportion and workability than
the arbitrary ratio gives. If little bit difference in volume or workability is
found, it may be adjusted very easily.
1850 1750
2.62 - 2.65 2.66 - 2.69 2.70 - 2.72
1450 1500
1700 1550
38 mm 1750
10 mm
20 mm
1450
1800 1600
Screened gravel
5
7. GENERAL
F
F
F
LIMITATION ACI METHOD
F It is better to design a concrete mix only up to 35 MPa of plastic state.
F
F
REQUIRED PARAMETERS OF INGREDIENTS
A. CEMENT
1. Grade and type as ACI - classification
2. Specific Gravity
B. FINE AGGREGATE
1. Gradation (Sieve Analysis)
2. Fineness Modulus (FM i.e. 2.4 to 3.1preferable)
3. Specific Gravity (SSD Bulk)
4. Absorption
Type-I, non air-entraining (OPC) as per ASTM/C-150, Specific Gravity
of 3.15
Coarse aggregate:- Gradation as per ASTM/C-33, Specific Gravity of
2.68, Absorption of 0.5%.
Fine Aggregate :- Gradation as per ASTM/C-33, Specific Gravity of
2.64, Absorption of 0.7%, FM of 2.8
The American Concrete Institute (ACI) has recommended an efficient
procedure of concrete mix design considering more economical use of
locally avilable materials to produce desirable workability, durability and
strength. The ACI method is able to produce concretes from very stiff to
fluid state workability as it is required in different conditions.The design
tables incorporating the basic relationships between the parameters, are
useful in selecting optimum combinations of the ingredients of non air-
entrained or air-entrained concrete mixes. The following design criteria are
assumed in formulating the design tables:
Though the specific gravity of coarse aggregate is taken 2.68 in this
ACI manual but if it is different see footnote of table-4.
It is important to note that the mix design tables serve as a guide in
selecting proportions and suitable minor adjustments should be
effected in the field for any departures in quality of aggregates and
type of cement used.
Before starting to design a concrete mix, it is very much important to have
all informations about concrete ingredients i.e physical test reports. These
physical parameters may be obtained by own laboratory test or by the
manufacturer. Basicaly for the design mix, the following parameters should
be available in the time.
7
8. C. COARSE AGGREGATE
1. Gradation (Sieve Analysis)
2. Dry Rodded Unit Weight
3. Specific Gravity (SSD Bulk)
4. Absorption
D. WATER
1. Chemical content(free of salt and alkalies)
2. Turbidity (potable or clear)
EQUIPMENT AND APPARATUS
A. SLUMP TEST 2. Mixer or mixing pan
1. Slump cone 3. Triple beam balance (1 g.)
2. Base plate 4. Scoop
3. Tamping rod 5. Straight edge
4. Graduated scale 6. Tamping rod or
5. Straight edge 7. Vibrator plate
6. Mixer (1 cft.) or 8. Rubber mallet
7. Mixing pan with shovel 9. Weighing containers
8. Scoop 10. Thermometer
9. Triple beam balance (1 g.) C. STRENGTH TEST
10. Weighing containers 1. Compressive St. machine
B. SAMPLE PREPARATION 2. Triple beam balance (1 g.)
1. 6 nos. cylinder or cube mould 3. Rubber sheet
To perform a mix design, the following equipment or apparatuses must be
available in advance:
10
15
20
25
30
35
40
45
50
0.36 0.40 0.44 0.48 0.52 0.56 0.60 0.64 0.68 0.72 0.76 0.80
CYLINDERSTRENGTHIN28DAYS(MPa)
WATER CEMENT RATIO
fig.- 1
RELATIONSHIP OF W/C RATIO TO STRENGTH
Non Air Entarined Mix
Air Entarined Mix
8
9. DESIGN GUIDE LINE
F
F
Percentage of
recommended average total air content.
F
3.5 3.08.0 7.0 6.0 5.0
112 to 56
56 to 28
4.5 4.0
Drop Table
Revolutions
160
170
175
185
180
190
135
-
150
160
155
165
165 160 145 140 135 120
80 - 100
150 - 180
180 175
190
205
200
215
20 - 50
Maximum Size of Coarse Aggregates (mm)
Air Entrained Concrete
20 25 40 50
0.3 0.2
percentage amount of entrapped air in non air entrained concrete.
Approximate
145
160
170
200
210
180
195
205
80 - 100
155
170
180
125
140
-
175
240 230150 - 180
225 215
Table : 1 Approximate Mixing of Water (Kg/m 3
of Concrete)
Requirements for Different Slumps and Maximum Size of Aggregates
Slump
(mm)
185
150
0.53 2 1.5 12.5
Non Air Entrained Concrete
10 12.5
205 200 185 16020 - 50
70
3 to 0
-
0.90
0.95
Compacting
Factor
-
0.70
0.75
0.85
Slump
25 - 50
75 - 100
150 - 175
Vebe
(Sec.)
32 to 18
18 to 10
10 to 5
5 to 3
Plastic
Flowing
(mm)
0 - 25
-
-
Extremely dry
Very stiff
Stiff
Stiff plastic
Firstly, to know the water cement ratio of concrete mix, find out it by
coinciding the required designed strength (i.e. minimum required
strength plus strength for safety factor as specified or assumed) to the
appropriate graph line mentioned in figure -1 above.
To know the quantity of water for 1 m3
of fresh concrete made in
screened river gravel, find out that required quantity with regarding the
desirable workability (slump) mentioned in table -1 below. This table
does not entertain crushed aggregate.
The way of inspection and testing of consistency or workability of
concrete may differ as the specification quotes in different projects, so
compare the following consistency as it requires.
28 to 14
14 to 7
7
-
Table : 2 Comparison of Consistency Measurements by Various Methods
Consistency
Description
9
10. F
0.53 #
Exposure Condition *
The exposure condition of structure may be affected by the climatic
condition, chemicals in contact (such as sulphate, salt, water etc) or
air. It means that durability of concrete should be considered as its
exposure condition that governs the strength of concrete (required w/c
ratio will be selected from the table-3 below).
Table : 3 Maximum Permissible Water Cement Ratios for Different Types
of Structures and Degrees of Exposure
Type of structures
At the water line or with in
the range of fluctuating
water level or spray
Severe wide range in
temperature, or frequent
alternations of freezing and
thawing (air entrained concrete
only)
In
air
At the water line or with in
the range of fluctuating
water level or spray
In fresh
water
In sea water or
in contact with
sulphates1
Mild temperature rarely below
freezing, or rainy, or aid.
In sea water or
in contact with
sulphates1
In fresh
water
In
air
1
Soil or ground water containing sulphate concentrations of more than 3.2%.
**When sulphate resisting cement (as per ACI type-V) is used, maximum water/cement ratio may be increased
by 0.13 litres per bag.
# Water/cement ratio should be selected on basis of strength workability requirements.
0.39
Concrete which will later be protected by
enclosure or backfill what which may be
exposed to freezing and thawing for
several years before such protection is
offered. 0.53 - - # - -
# - #
*Air entrained concrete concrete should be used under all conditions involving severe exposure and may be
used under mild exposure conditions to improve workability of the mixture.
Concrete protected from weather,
interiors of buildings, concrete below
ground. - - -
0.44
Concrete slabs laid on the ground. -- - -
Concrete deposited by tremie under
water - 0.44 0.44
0.44**
Exterior portions of heavy (mass)
sections. 0.57 0.48 0.44 # 0.53 0.44**
- 0.44
0.53 0.48
# 0.53
0.390.44
Thin sections, such as railings, curbs,
sills, ledges, ornamental or architectural
concrete, reinforced piles, pipes and all
sections with less than 25 mm. Concrete
cover reinforcing.
Moderate sections, such as retaining
walls, abutments, piers, girders, beams. 0.53 0.48 0.44**
0.48
10
11. F
Where,
VA = apparent vol. of solid particles per unit volume of concrete
g1 = used specific gravity
VD = Vol. of dry rodded agg. per unit volume of concrete
F
for example:
VC = f x VA = 1.15 x 0.62 = 0.71
Where,
VC = corrected vol. of aggregate in per unit vol. of stiff concrete
f = multiplying factor from table-5 (next page)
VA = apparent vol. of solid particles per unit volume of concrete from table-4
0.65 0.63
0.6620 0.60 0.58
0.5912.5 0.53 0.51
0.5010 0.44 0.42
Table : 4 Volume of Dry Rodded Coarse Aggregates per Unit
Volume of Concrete (V D ) only for Plastic Consistency
Maximum Size of
Coarse Aggregate 2.60 3.00 3.202.802.40
Fineness Modulus (FM) of Sand
Find out the volume of aggregate for per unit volume of concrete with
respect to the fineness modulus of sand and nominal maximum size of
aggregate. The value not given in following table will be determined by
interpolation of given value which are only for the particular aggregate
with specific gravity of 2.68. If our specific gravity is different then, see
the note of table 4.
0.70 0.68
50 0.76 0.72 0.70
0.74 0.72
0.74
40
To determine the exact volume of coarse aggregate in per unit volume
of concrete in non-plastic consistency (i.e. in stiff condition), select the
appropriate multiplying factor (f) listed below to the volume mentioned
in table-4. For example, see note#
of table-5 in next page.
0.77
0.83
Note: The volume of dry rodded coarse aggregate recommended in above table, applies to the aggregate of the
given specific gravity g which in this case is 2.68. If the aggregate used has a specific gravity g 1 , the volume of
coarse aggregates specified in the table should be multiplied by the ratio (g 1 /g ) to account for gross apparent
volume (VA) of solid particles. i.e. V A = g 1 /2.68xV D
0.75 0.73
150 0.85
0.71
0.76
0.78
0.81 0.7970
25
0.46
0.55
0.62
0.67
0.48
0.57
0.64
0.69
0.81 0.790.87
If it is to prepare a concrete mix with a slump (0 - 25 mm) and 20 mm aggregate in a
sand with FM 2.8 then the corrected volume of coarse aggregate per unit volume of
11
12. F
10 12 20 25 40
177 168 158 148 137
188 182 168 158 148
196 192 177 168 158
206 196 182 177 162
226 217 203 192 177
240 226 212 203 188
3.0 2.5 2.0 1.5 1.0
158 148 137 133 123
168 158 148 137 133
177 168 158 148 137
182 177 162 152 143
203 192 177 168 158
212 203 188 177 168
8.0 7.0 6.0 5.0 4.5
Percentage of approximate amount of entrapped air in non-air - entrained concrete,
Air-Entrained Concrete
78
83
88
106
0.91
0.95
Stiff plastic 92
Plastic
Flowing
75 - 100
150 - 175
100
-
0.70
0.75
0.85
Non - Air-Entrained Concrete
Workability
-
112 - 56
56 - 28
28 - 14
14 - 7
7
-
18 to 10
10 to 5
5 to 3
3 to 0
Factors for Maximum Size of Coarse Aggregate (mm)
1.09
1
11
12.5
1.7
Water, Kg. Per m3
for
indicated maximum size
of C. A. (mm)
Relative
Water
content
(%)
1.06
1
1
40
1.3
1.25
1.21.15
25
1.4
1.25
1.15
Consistence
1
1.45
1.3
10
1.9
1.6
1.35
20
1.45
1.3
1.08 1.06
Drop
Table
Revolutions
Compacting
Factor
Fluid
1
0.97
Plastic (Reference)
0.98
1.04
Table : 6 Approximate Mixing of Water (Kg/m 3
of Concrete) Required for
Different Consistencies and Maximum Size of Aggregates *
Stiff
Very stiff
Extremely dry
Extremely dry
1
-
Slump
(mm)
Vebe,
(sec.)
Stiff plastic
-
0 - 25
25 - 50
Very Stiff
Stiff
Table:5 Factor ( f ) to Applied to the Volume of Coarse Aggregate
Calculated on the Basis of Table:4, for Mixes of Consistence Other than
Plastic
32 to 18
To know the quantity of water for 1 m3
of fresh concrete made in
crushed aggregate, find out that required quantity with regarding the
desirable workability (slump) mentioned in table -6 below. This table
does not entertain the aggregate produced by screened river gravel.
Extremely dry - 32 to 18 112 - 56 - 78
Stiff 0 - 25 10 to 5 28 - 14
Very Stiff - 18 to 10 56 - 28 0.70 83
0.75 88
0.85 92
0.91 100
Stiff plastic 25 - 50
Plastic 75 - 100 3 to 0 7
5 to 3 14 - 7
0.95 106
Recommended average total air content, percent (%)
Flowing 150 - 175 - -
* These quantities of mixing water are use in computing factors for trial batches. They are for reasonably well-
shaped angular coarse aggregates graded within limits of accepted specifications. If more water is required
than shown, the cement factor, estimated from these quantities, should be increased to maintain desired water-
cement ratio, except as otherwise indicated by laboratory tests for strength.
12
14. F
FM = 284.40 /100 = 2.84
SUMMARY OF DESIGN PROCEDURE
F
F
F
F
F
F
F
F
F
F
F
% of Retained
Now prepare three sample after varying W/C ratio with 5% more & 5%
less but keeping the quantity of water same in two of them.
Test these three sample in specified time and plot graph strength vs
W/C ratio. Here it is determined the actual W/C ratio required for min.
design strength graphically.
% of
Passing
Similarly, multiplying the dry rodded density to volume required as per
table-4, find out the quantity of coarse aggregate required.
Determine the min. design strength including safety factor for site.
25 to 60
10 to 30
2 to 10
Find the fineness modulus (FM) of sand from the sieve analysis report
prepared in laboratory same as demonstrated in table-7 below.
Now calucate the absolute volume of concrete by using the respective
specific gravity of materials excluding sand.
Find out the W/C ratio as per strength consideration using fig.-1 or as
per durability in exposer consideration table-3, whichever is lower.
Determine the quantity of water required and percentage of air
entraining using table-1 or table-6 as the coarse aggregate is used.
Find out the volume of coarse aggregate using table-4 and table-5,
with respect to FM value as well as specific gravity of sand.
Thus find out the quantity of cement having value of W/C ratio and
water required for 1 m3
of concrete.
50 to 85
6.414.2
Table : 8 Example , Determination of Fineness Modulus of Fine Aggregate
(Sand) from Sieve Analysis Report
ACI Specification
Limit (ASTM:C-
33)
95 to 100
80 to 100
% cum.
Retained
0.0
8.5
Mass of
Retained
(gms)
0.0
60.0
-
100.0
91.5
63.1
20.6
2.8
-
97.2
100.0
42.6
3.5
2.820.0
200.0
300.0
100.0
25.0
36.9
0.0
8.5
28.4
79.4
93.6
No # 8 2.36
No # 16
No # 30 0.60
No # 50 0.30
Sieve Size
BS mm
No # 100 0.15
Pan
1.18
No # 4 4.75
TOTAL 705 284.4
Collect the all the properties of concrete materials by conducting
necessary tests.
Then subtracting that absolute volume in 1 m3
volume, the remaining
value will be determined as the volume of sand which is converted in
weight by using the specific gravity of sand.
14
15. Mix Design Data Sheet
TRIAL MIX TM-….… A
Project A1
Location A2
Structure A3
Member A4
Concrete Class A5
Type and Brand of Cement A6
Source of Fine Aggregate A7
Type of Coarse Aggregate A8
Source of Coarse Aggregate A9
Specific Gravity of Cement A10
Specific Gravity of Fine Aggregate A11
Fineness Modulus (FM) of F.A. (as determined in table-7) A12
Nominal Max. Size of Coarse Aggregate (mm) A13
Specific Gravity of Coarse Aggregate A14
Rodded Unit Weight of Coarse Aggregate (Kg/m3) A15
Minimum Cylinder Strength Required #
(MPa) A16
Percentage of Safety Factor Specified (%) A17
Net Design Cylinder Strength (MPa) A18
Water Cement Ratio (wc1) - [whichever is lower below] A20
Strength Consideration (fig.-1) or Durability Consideration (table-2 )
Desirable Workability (Slump) (mm) A21
*Required Weight of Water (table-1or 6) (Kg/m3) A22
*Entrained Air in Concrete (table-1 or 6) (%) A23
(* If the coarse aggregate is crushed rock i.e angular shape, use table-6)
Volume of Coarse Aggregate Required (table-4) A24
TRIAL MIX TM-….… B
Water Cement Ratio (wc2) - [10% more than specified] A25
TRIAL MIX TM-….… C
Water Cement Ratio (wc3) - [10% lesser than specified] A26
A16 + (A17/100)xA16
( # If cube strength is required, select 80% of cylinder strength above i.e Cube Strenght = 1.2 x Cyl. Strength )
A20 + 0.10 x A20
A20 - 0.10 x A20
15
16. Design Steps
TRIAL MIX TM-….… A
Weight of water Required (Kg/m3
) B1
Weight of Coarse Aggregate Required (Kg/m3) B2
Weight of Cement Required (Kg/m3) B3
Solid Volume of Cement in Concrete (cc) B4
Solid Volume of Water in Concrete (cc) B5
Solid Volume of Coarse Aggregate in Concrete (cc) B6
Volume of Entrained Air in Concrete (cc) B7
Total Volume of Ingredients (except F. Agg.) (cc) B8
Required Volume of Fine Aggregate in Concrete (cc) B9
Weight of Fine Aggregate Required (Kg/m3) B10
ESTIMATED BATCH QUANTITY
Cement (Kg)
Water (Kg)
Fine Aggregate (Kg)
Coarse Aggregate (Kg)
Density of Fresh Concrete (Kg/m3
)
0.007 x B1
For 1 m3
Volume
Ingredients
NOTE: Here, check the slump of this TRIAL-A. If the desirable slump range is not obtained,
recalculate by increasing or decreasing the weight of water by 5% again and again until the slump is
maintained but keeping the W/C ratio same. After maintaining the desirable slump, prepare six nos. of
sample (cylinder or else) for strength test and then proceed to TRIAL -B.
0.04 x B2B2
0.04 x B10B10
B3+B1+B10+B2
0.007 x B2
0.007 x B10
40 Litres for Lab.
Sample
B1
7 Litres for Slump
Test
0.007 x B3
0.04 x B1
0.04 x B3B3
B3 x 1000 / A10
A23 /100 x 1000000
B4+ B5+ B6+ B7
1000000 - B8
B9 x A11 /1000
B2 x 1000 / A14
A24 x A15
A22
B1 / A20
B1 x 1000
16
17. Design Steps
TRIAL MIX TM-….… B
Weight of water Required (Kg/m3
) C1
Weight of Coarse Aggregate Required (Kg/m3) C2
Weight of Cement Required (Kg/m3) C3
Solid Volume of Cement in Concrete (cc) C4
Solid Volume of Water in Concrete (cc) C5
Solid Volume of Coarse Aggregate in Concrete (cc) C6
Volume of Entrained Air in Concrete (cc) C7
Total Volume of Ingredients (except F. Agg.) (cc) C8
Required Volume of Fine Aggregate in Concrete (cc) C9
Weight of Fine Aggregate Required (Kg/m3) C10
ESTIMATED BATCH QUANTITY
Cement (Kg)
Water (Kg)
Fine Aggregate (Kg)
Coarse Aggregate (Kg)
Density of Fresh Concrete (Kg/m3
)
Note: Prepare minimum 6 nos. of samples (cube or cylinder). 3 nos for 7 days and 3 nos. for 28 days.
C1 / A25
C3 x 1000 / A10
A23 /100 x 1000000
C9 x A11 /1000
0.04 x C1
A22
Ingredients
For 1 m3
Volume
7 Litres for Slump
Test
40 Litres for Lab.
Sample
C3 0.007 x C3 0.04 x C3
C4+ C5+ C6+ C7
1000000 - C8
C1 x 1000
C2 x 1000 / A14
A24 x A15
C10 0.007 x C10 0.04 x C10
C1 0.007 x C1
C3+C1+C10+C2
C2 0.007 x C2 0.04 x C2
17
18. Design Steps
TRIAL MIX TM-….… C
Weight of water Required (Kg/m3
) D1
Weight of Coarse Aggregate Required (Kg/m3) D2
Weight of Cement Required (Kg/m3) D3
Solid Volume of Cement in Concrete (cc) D4
Solid Volume of Water in Concrete (cc) D5
Solid Volume of Coarse Aggregate in Concrete (cc) D6
Volume of Entrained Air in Concrete (cc) D7
Total Volume of Ingredients (except F. Agg.) (cc) D8
Required Volume of Fine Aggregate in Concrete (cc) D9
Weight of Fine Aggregate Required (Kg/m3) D10
ESTIMATED BATCH QUANTITY
Cement (Kg)
Water (Kg)
Fine Aggregate (Kg)
Coarse Aggregate (Kg)
Density of Fresh Concrete (Kg/m3
)
Note: Prepare minimum 6 nos. of samples (cube or cylinder). 3 nos for 7 days and 3 nos. for 28 days.
D2 0.007 x D2 0.04 x D2
D4+ D5+ D6+ D7
1000000 - D8
D9 x A11 /1000
Ingredients
For 1 m3
Volume
7 Litres for Slump
Test
D3+D1+D10+D2
D10 0.007 x D10 0.04 x D10
D1 0.007 x D1 0.04 x D1
40 Litres for Lab.
Sample
A22
A24 x A15
D1 / A26
D3 x 1000 / A10
D1 x 1000
D2 x 1000 / A14
A23 /100 x 1000000
D3 0.007 x D3 0.04 x D3
18
19. Compressive Strength Test of Sample
TRIAL MIX TM-….… A
"
"
"
"
"
TRIAL MIX TM-….… B
"
"
"
"
"
TRIAL MIX TM-….… C
"
"
"
"
" " s6 = p6 / a
W/CRatio
Compressive
Load (N)
p1
p2
p3
p4
p5
p6
X28=(S1+S2+S3)/35 28 " s5 = p5 / a
6 28
4 28 " s4 = p4 / a
3 7 "
Age of
Sample
(day)
W/CRatio
Compressive
Load (N)
s3 = p3 / a
Sectional
Area
(mm2
)
Compressive
Strength (Mpa)
28 p6
s4 = p4 / a
s2 = p2 / a
7 "
7
Age of
Sample
(day)
p4
p5
Sectional
Area
(mm2
)
p2 "
" s6 = p6 / a
1 7
6
Remarks
1 7 a s1 = p1 / a
X7=(S1+S2+S3)/32
Sample
No.
s2 = p2 / a
X28=(S1+S2+S3)/3
4 28 "
Average
Strength (Mpa)
5 28 " s5 = p5 / a
p3
Average
Strength (Mpa)
Remarks
X7=(S1+S2+S3)/3
3 7 " s3 = p3 / a
Sample
No.
" s6 = p6 / ap6
X28=(S1+S2+S3)/3
2
Compressive
Strength (Mpa)
p1 a s1 = p1 / a
p4 " s4 = p4 / a
p3
" s5 = p5 / ap5
2
Sample
No.
Age of
Sample
(day)
W/CRatio
Compressive
Load (N)
7 p1
7 p2
Remarks
"
1
X7=(S1+S2+S3)/3
Sectional
Area
(mm2
)
Compressive
Strength (Mpa)
" s3 = p3 / a
a
5
6
7
28
28
28
3
4
s1 = p1 / a
Average
Strength (Mpa)
s2 = p2 / a
19
20. Graphical Determination of Required W/C Ratio
Summary of Designed Mix
TRIAL MIX TM-….… B
TRIAL MIX TM-….… A
TRIAL MIX TM-….… C
TRIAL MIX TM-11, B
TRIAL MIX TM-11, A
TRIAL MIX TM-11, C
Mix Design W/C Ratio
7 Days Strength
(Mpa)
28 Days Strength
(Mpa)
as per design
Remarks
W/C2 w/c=5% more
W/C Ratio
7 Days Strength
(Mpa)
28 Days Strength
(Mpa)
W/C1
18 25 w/c=5% more
Remarks
Example: A tipical required value of W/C ratio (as shown in fig.-2) for
minimum design strength is determined by the observed data as
demontrated below.
W/C3 w/c=5% less
Mix Design
0.52 21 30 as per design
0.48 27 39 w/c=5% less
0.56
10
15
20
25
30
35
40
45
50
0.560.520.48
CompressiveStrength(MPa)
W/C Ratio
Fig.- 2
Determination of Actual W/C Ratio
Design Strength
RequiredW/CRatio
Example:
For Design Str. = 32 Mpa
Requires W/C Ratio = 0.51
20
22. GENERAL
FEATURE DESIGN
F
F
F
In general, only a natural sand is needed for use of fine aggregate
because high strength are rarely obtained with crushed rock fine
aggregate.
Crushed aggregate (possibly granite) is more preferred than that use
of irregular gravel coarse aggregate for strength assurance.
Low workability is introduced instead of high degree of workability.
This high strength concrete mix design has been developed by B. W.
Shacklock and H. C. Erntroy in 1954. For designing concrete mix of low
and medium grade compressive strength i.e. up to 35 MPa, it is assumed
the strength of fully compacted concrete at a required age to be dependent
only on the w/c ratio of the mix. However, compressive strength of high-
strength mix above 35 MPa is mainly influenced by the properties of
aggregates in addition to that of w/c ratio. The methods of mix design used
for medium grade concrete cannot therefore, govern to lead to an accurate
estimate of the required mix proportions for high strength concrete under
all circumstances.
The methods of high strength design-mix has been developed on the basis
of these following features:
0
10
20
30
40
50
60
70
80
90
0 10 20 30 40 50 60 70
COMPRESSIVESTRENGTH(MPa)
REFERENCE NUMBER
Fig.1
IRREGULAR GRAVEL COARSE AGGREGATE WITH NATURAL
SAND AND ORDINARY PORTLAND CEMENT
22
23. F
F
LIMITATION OF HIGH STRENGTH DESIGN
F
F
F Graphical tables are used instead of analytical formulas or so on.
F
Combined grading of total aggregates may be assumed to be constant
with 30% passing in No. #4 sieve (4.75 mm size sieve).
No concrete of plastic consistency is suggested to design but only stiff
mix is preferred to get high strength.
Nominal maximum size of aggregate(NMSA) is taken only up to 20
mm. Maximum.
These graphs used (to find out the Reference Number) in this method
are obtained from the aggregates containing 30% of material passing
through the 4.75 mm sieve. If other grading are used, suitable
adjustment have to be made as shown in fig. - 7.
An arbitrary reference number is determined from a graph connecting
average design strength and reference number which is needed to
know the required water cement ratio (w/c) for the particular strength.
0
10
20
30
40
50
60
70
80
90
0 10 20 30 40 50 60 70
COMPRESSIVESTRENGTH(MPa)
REFERENCE NUMBER
Fig. 2
CRUSHED GRANITE COARSE AGGREGATE WITH NATURAL
SAND AND ORDINARY PORTLAND CEMENT
23
24. REQUIRED PARAMETERS OF INGREDIENTS
A. CEMENT
1. Grade and type
2. Specific Gravity
B. FINE AGGREGATE
1. Gradation (Sieve Analysis)
2. Specific Gravity (SSD Bulk)
3. Absorption
C. COARSE AGGREGATE
1. Gradation (Sieve Analysis)
2. Specific Gravity (SSD Bulk)
3. Absorption
As usual for designing a concrete mix, it is very much important to be
known all information about concrete ingredients i.e. physical test reports.
These physical parameters may be obtained by own laboratory - test or by
the manufacturer. Basically for the high strength design mix, the following
parameters should be available in the time.
0
10
20
30
40
50
60
70
80
90
0 10 20 30 40 50 60 70
COMPRESSIVESTRENGTH(MPa)
REFERENCE NUMBER
Fig. 3
IRREGULAR GRAVEL COARSE AGGREGATE WITH NATURAL
SAND AND RAPID HARDENING PORTLAND CEMENT
24
25. D. WATER
1. Chemical content(free of salt and alkalis)
2. Turbidity (potable or clear)
DESIGN PROCEDURE
F
F
F
F
F
Find out the arbitrary reference number according to necessity and
availability of concrete materials using fig. 1, 2, 3, 4.
Determine the water/cement ratio (w/c) in terms of reference number
using fig. 5, 6.
Knowing the type of aggregate, size of aggregate, degree of workability
and water cement ratio (w/c), find the aggregate/cement ratio using
table- 1 or table- 2.
Plot the gradation (percentage passing) of available materials i.e. fine
aggregate and coarse aggregate as shown in fig. 7 and then determine
the required fine aggregate/total aggregate ratio connecting with 30%
passing line.
Estimate the average design strength using standard deviation or as it
is specified for the special job.
0
10
20
30
40
50
60
70
80
90
0 10 20 30 40 50 60 70
COMPRESSIVESTRENGTH(MPa)
REFERENCE NUMBER
Fig. 4
CRUSHED GRANITE COARSE AGGREGATE WITH NATURAL SAND
AND RAPID HARDENING PORTLAND CEMENT
25
26. EQUIPMENT AND APPARATUS
For preparing the sample following euipments are needed:
1. 6 nos. Cylinder or Cube Mould 4. Scoop 7. Rubber Mallet
2. Mixer or Mixing Pan 5. Straight Edge 8. Tamping Rod or Vibrator
3. Triple Beam Balance (1 g.) 6.Thermometer 9. Weighing Containers
To find out the strength of specimens following equipment are needed :
1. Compressive Strength Machine
2. Triple Beam Balance (1 g.)
3. Rubber Sheet (Filler)
To perform a mix design, no special equipment or apparatus is required
more than it requires for normal mix design except a special vibrating
machine is needed to compact the stiff concrete-sample. For the stiff
concrete no hand-mixing is suggested to come true reporting results and
hence is always preferred laboratory mixer to mix vigorously.
0.30
0.32
0.34
0.36
0.38
0.40
0.42
0.44
0.46
0.48
0.50
0 10 20 30 40 50 60 70
WATER/CEMENTRATIO
REFERENCE NUMBER
Fig. 5
20 mm. AGGREGATE
Degree of Workability
26
27. 3.0 2.4 3.3 2.9
3.8 2.5 3.2 4.0 2.6 3.6 2.3
4.5 3.0 2.5 3.9 2.6 4.6 3.2 2.6 4.2 2.8 2.3
5.2 3.5 3.0 2.5 4.6 3.1 2.6 5.2 3.6 3.1 2.6 4.7 3.2 2.7 2.3
4.0 3.4 2.9 5.2 3.5 3.0 2.5 4.1 3.5 2.9 5.2 3.6 3.0 2.6
4.4 3.8 3.2 3.9 3.3 2.7 4.5 3.8 3.2 4.0 3.3 2.9
4.9 4.1 3.5 4.3 3.6 3.0 4.9 4.2 3.5 4.4 3.6 3.1
5.3 4.5 3.8 4.7 3.9 3.3 5.3 4.5 3.7 4.8 3.9 3.3
4.8 4.1 5.1 4.2 3.6 4.8 4.0 5.1 4.2 3.6
5.2 4.4 5.4 4.5 3.8 5.1 4.2 5.5 4.5 3.8
5.5 4.7 4.8 4.0 5.4 4.5 4.7 4.0
* Natural sand used in combination with both types of coarse aggregates.
+ EL = Extremely Low VL = Very Low L = Low M = Medium
0.46
0.48
WaterCementRatio(byweight)
0.34
0.36
0.50
Crushed GraniteIrregular Gravel
Degree of
Workability +
Type & Size
of C. A. *
EL VL L EL VL L M
20 mm Size 10 mm Size 20 mm Size
M EL VL
10 mm Size
L ML MEL VL
0.44
0.38
0.40
0.42
0.30
Table- 1: Aggregate / cement ratio (by weight) required to give four
degrees of workability with different water cement ratios using Ordinary
Portland cement
0.32
0.30
0.32
0.34
0.36
0.38
0.40
0.42
0.44
0.46
0.48
0.50
10 20 30 40 50 60 70
WATER/CEMENTRATIO
REFERENCE NUMBER
Fig. 6
10 mm. AGGREGATE
Degree of Workability
27
28. 2.6 2.9 2.5
3.4 2.2 2.8 3.6 2.4 3.2
4.1 2.7 2.3 3.5 2.4 4.3 2.9 2.4 3.9 2.5
4.8 3.2 2.8 2.3 4.2 2.9 2.4 4.9 3.4 2.9 2.4 4.5 3.0 2.5
5.5 3.7 3.2 2.7 4.9 3.3 2.8 2.3 5.5 3.9 3.3 2.7 5.0 3.4 2.9 2.4
4.2 3.6 3.0 3.7 3.0 2.6 4.2 3.6 3.0 5.5 3.8 3.2 2.7
4.6 4.0 3.4 4.1 3.5 2.9 4.7 4.0 3.3 4.2 3.5 3.0
5.0 4.3 3.7 4.5 3.8 3.2 5.1 4.3 3.6 4.6 3.8 3.2
5.5 4.7 4.0 4.9 4.1 3.5 5.5 4.6 3.9 5.0 4.1 3.4
5.0 4.3 5.2 4.4 3.7 4.9 4.1 5.3 4.4 3.7
* Natural sand used in combination with both types of coarse aggregates.
+ EL = Extremely Low VL = Very Low L = Low M = Medium
0.36
LEL VL L M M ELEL
Type & Size
of C. A. *
Irregular Gravel Crushed Granite
20 mm Size 10 mm Size 20 mm Size 10 mm Size
M
Table- 2: Aggregate / cement ratio (by weight) required to give four
degrees of workability with different water cement ratios using Rapid
Hardening Portland cement
Degree of
Workability +
EL VL L VL LM VL
WaterCementRatio(byweight)
0.46
0.48
0.50
0.38
0.40
0.42
0.44
0.32
0.34
Line of 30% Passing
RequiredRatio=24%
0
10
20
30
40
50
60
70
80
90
100
0 10 20 30 40 50 60 70 80 90 100
PercentagePassingofC.A.
10 mm
4.75 mm
2.36 mm
1.18 mm
0.60 mm
0.30 mm
0.15 mm
PercentagePassingofF.A.
10 mm
20 mm
4.75 mm
2.36 mm
28
29. Mix Design Data Sheet
TRIAL MIX: TM - …. A
Project A0
Location A1
Structure A2
Member A3
Concrete Class A4
Type and Brand of Cement A5
Source of Fine Aggregate A6
Type of Coarse Aggregate A7
Source of Coarse Aggregate A8
Specific Gravity of Cement A9
Specific Gravity of Fine Aggregate A10
Specific Gravity of Coarse Aggregate A11
Nominal Max. Size of Coarse Aggregate (mm) A12
Minimum Cylinder Strength Required # (MPa) A13
(# If cube strength is required, select 80% of cylinder strength above)
Additional Strength for Safety Factor (MPa) A14
Average Design Cylinder Strength (MPa) A15
Arbitrary Reference Number (from fig. 1, 2, 3 or 4) A16
Degree of Workability (as required) A17
Water Cement Ratio (from fig. 5 or 6) A18
Total Aggregate to Cement Ratio (from table 1 or 2) A19
% of Fine Aggregate to Total Aggregate (from fig. 7) A20
A13+A14
29
30. Design Steps
TRIAL MIX: TM - A
A : Mix Proportion by Weight (with reference to cement)
1 Cement B1
2 Water B2
3 Fine Aggregate B3
4 Coarse Aggregate B4
B : Absolute Volume (for 1 m3
)
1 Cement B5
2 Water B6
3 Fine Aggregate B7
4 Coarse Aggregate B8
B9
Required Weight of -
Cement B10
Water B11
Fine Aggregate B12
Coarse Aggregate B13
C : Batching for
CEMENT
WATER
FINE AGGREGATE
COARSE AGGREGATE
Materials Unit 1 m3
Volume
* Lab.Sample
for 40 Lit. Vol.
A18
A20/(100x A19)
{1-(A20/100)}x A19
B1/A9
B4/A11
* Note : Estimated quantity 40 liters is for 6 nos. of cylindrical moulds
(size dia. 15 cm & ht. 30 cm.). If it is to prepare 6 nos. of 15x15x15 cm.
cubical moulds, take 25 liters volume for laboratory sample.
0.04xB12
0.04xB13
B12
B13Kg
Kg
1000/B9
B3xB10
A18
B2xB10
B5+B6+B7+B8
B3/A10
1
B4xB10
Density of Fresh Concrete (Kg/m
3
) B10+B11+B12+B13
B10
B11
0.04xB10
0.04xB11
Kg
Kg
30
