1. CONCRETE MIX DESIGN

2. CONCRETE MIX DESIGN

3. CONCRETE MIX DESIGN

4. CONCRETE MIX DESIGN

5. CONCRETE MIX DESIGN
Basically, the problem of designing a concrete mix consists of selecting the correct proportions of cement, fine and coarse aggregate and water to produce concrete having the specified properties.
There are many properties of concrete that can be specified, eg workability, strength, density, thermal characteristics, elastic modulus and durability requirements. The properties most usually specified are:
The workability of the fresh concrete
The compressive strength at a specified age
The durability, by means of specifying the minimum cement content and/or the maximum free-water/ cement ratio and, in some cases, requiring the use of selected types of materials

6. CONCRETE MIX DESIGN - SPECIFICATION
Characteristic Compressive Strength = days
Spec. strength margin = 5 N/mm2
PC Class 42.5N
Slump Required 60 – 180mm
Max aggregate size = 10mm
Coarse aggregate = crushed
Fine aggregate = uncrushed
Relative density of aggregates (SSD) = 2.7
Fine aggregate passing a 600μ sieve = 70%

7. 40 28 5 40 5 45

8. Produce your chart

9. Free water/ cement ratio
0.53

10. 40 28 5 40 5 45
0.53
0.53
60-180 10

11. Free water Content (Coarse agg)

12. Free water Content (Fine agg)

13. 2/3 Wf + 1/3 Wc
2/ /3 250
= 233

14. 40 28 5 40 5 45
0.53
0.53
60-180 10
233

15. 233
0.53
440
440
2.7

16. Stage 4 requires an estimate of the density of the fully compacted concrete
2370

17. 233 0.53 440 440 2.7 2370 2370 233 440 1697 Wet density of concrete
Figure 5
Cement Content
Free Water Content

18. 233
0.53
440
440
2.7
2370
2370
233
440
1697 70

19. Stage 5 requires determination of the proportion of fine aggregate
40%

20. 233
0.53
440
440
2.7
2370
2370
233
440
1697 70 40
1697
40%
679
1697
679
1018
Total Aggregate

21. SUMMARY OF QUANTITIES
440
235
680
1020 1
440
235
680
1020