A) Stipulations for proportioning:- a) Grade designation: M30, b) Standard deviation, s=5, c) Type of cement: OPC 43 grade conforming to IS8112, d) Workability: 75 mm (slump), e) Degree of supervision: Good, f) Type of aggregate: Angular coarse aggregate, g) Maximum cement content: 450 kg/m3.
B) Test data for Materials:
a) Specific gravity of cement: 3.15, b) Specific gravity of:
i) Coarse aggregate-2.74
ii) Fine aggregate-2.74
c) Water absorption:-
i) Coarse aggregates - 0.5%
ii) Fine aggregates - 1.00%.
d) Free surface moisture:
i) Coarse aggregates - Nil (absorbed moisture also nil)
ii) Fine aggregates ?Nil
e) Sieve analysis:
i) Coarse aggregate:
IS Sieve Sizes (mm) | Analysis of Coarse Aggregate Fraction | Percentage of different Fraction | Remarks | |||
I | II | I (60%) | II (40%) | Combined (100%) |
Confirming of Table 2 of IS 383 |
|
20 10 4.75 2.36 |
100 0
|
100 71.2 9.40 0 |
60 0
|
40 28.5 3.7
|
100 28.5 3.7
|
ii) Fine aggregate: Conforming to grading zone I
C) Design considerations:
Table 1: From IS 10262; Maximum water content per cubic meter of concrete:
Sr. No. | Nominal Maximum Size of Aggregate | Maximum Water Content (kg) |
(i) (ii) (iii) |
10 20 40 |
208 186 165 |
Table 2: From IS 10262; Volume of Coarse Aggregate per Unit Volume of Total Aggregate:
Sr. No. (1) |
Nominal Maximum Size of Aggregate (mm) (2) |
Volume of Coarse Aggregate per Unit Volume of Total Aggregate for Different Zones of Fine Aggregate | |||
Zone IV | Zone III | Zone II | Zone I | ||
(i) (ii) (iii) |
10 20 40 |
0.50 0.66 0.75 |
0.48 0.64 0.73 |
0.46 0.62 0.71 |
0.44 0.60 0.69 |
Table 3: From IS 456; Different exposure conditions for reinforced concrete:
Sr. No. | Exposure | Minimum cement content (kg/cubic m) | Maximum free water cement radio | Minimum grade of concrete |
(i) (ii) (iii) (iv) (v) |
Mild Moderate Severe Very Severe Extreme |
300 300 320 340 360 |
0.55 0.50 0.45 0.45 0.40 |
M20 M25 M30 M35 M40 |