Packing density is new kind of mix design method used to design different types of concrete. To optimize the particle packing density of concrete, the particles should be selected to fill up the voids between large particles with smaller particles and so on, in order to obtain a dense and stiff particle structure.

1. A Presentation on
Concrete Mix Design by Packing Density
Method

2. OUTLINE
• CHAPTER 1- Introduction
• CHAPTER 2- Design Procedure for M20 Grade Concrete
• CHAPTER 3- Determination of Aggregate Fractions
• CHAPTER 4- Determination of Packing Density
• CHAPTER 5- Determination of Void Content
• CHAPTER 6- Determination of Paste Content
• CHAPTER 7- Determination of Aggregate Content
• CHAPTER 8- Determination of Cement & Water Content
• CHAPTER 9- Conclusion

3. CHAPTER-1
Introduction -
• Packing density is new kind of mix design method used to design different
types of concrete; Normal concrete, high strength concrete, no-fines
concrete and self compacting concrete.
• The concept of packing density as a fundamental principle for designing
High performance concrete (HPC) mixes
• HPC has become more and more popular in recent years.
• The conventional mix design methods are no longer capable of meeting the
stringent multiple requirements of HPC.

4. CONTD...
• The packing density method concept is based on the belief that the
performance of a concrete mix can be optimized by maximizing the
packing densities of the aggregate particles and the cementitious
materials.
• Multi-sized aggregate can be packed together much more effectively to
achieve a much higher packing density than single size.
• With the paste volume fixed, increase in packing density of the aggregate
increase the workability of the concrete at the same water/cementitious
ratio.
• Increase in packing density of the aggregate could also be employed to
improve the dimensional stability of the concrete.

5. CONTD...
• The concept of packing density can be extended to apply also to the
cementitious materials.
• The packing density of the cementitious materials has great impact on the
strength of the concrete produced.
 Lower water/cementitious ratio
 Better packing would reduce the permeability
 Reduce the porosity of the transition zone
• Major factors affecting the packing density of an aggregate; size range,
grading, particle shape, surface roughness, and effectiveness of the mixing
and compaction processes.

6. CHAPTER-2
Design Procedure for M20 Grade Concrete :-

7. CHAPTER-3
First step:- Determination of aggregate fractions :-
 Considering different coarse aggregates size.
 Determine the bulk density of coarse aggregates separately.
 Mix coarse aggregates in different proportions.
 Determine the bulk density of mix different size aggregates.
 Draw the graph of bulk density against fraction of different size
proportion aggregates.

8. CONTD...
 Based on the graph optimal aggregate fractions is selected ( fraction
corresponding to maximum bulk density)
 Two size fractions of coarse aggregates are selected for the mix
design, 20mm and 12.5mm down size, the coarse aggregate 20mm
and 12.5mm were mixed in different proportions by mass, such as
90:10, 80:20, 70:30 and 60:40 etc.

9.  Then Fine aggregate is added in the total coarse
aggregates (20mm and 12.5mm) in different
proportions, the bulk density and weight fraction of each
mixture is determined.
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10.  For Coarse Aggregates:
 From Standard Test:
10

11. From the above graph the maximum bulk density is
corresponding to fraction of x=0.3. Therefore, the coarse
aggregates proportion is (70:30).
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12.  For coarse aggregates + Fine aggregate: (60:40)
 From standard test:
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From the above graph the mamximum bulk density is
corresponding to fraction of x= 0.4 , therefore the mix
proportion is : Coarse aggregates: Fine aggregate=(60:40)
So aggregates proportion is: (42:18:40)

14.  Total packing density of the mixture is sum of packing density of
different size coarse aggregates and fine aggregate.
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CHAPTER-4
Second Step:- Determination of Packing Density:-

15. 15

16. CHAPTER-5
Third step: Determination of Voids Content:-
 The voids content in percentage volume of aggregate or
mixture of three aggregate is determined from its bulk density
from the fallowing relations.
 The value of specific gravity should be taken as average.

17. Minimum voids contents (0.2866) is corresponding to x=0.4
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18. CHAPTER-6
Fourth step: Determination of paste content:-
 Minimum paste content is sum of the void content in combined
aggregate and excess paste over and above it to coat the
aggregate particle.
 Concrete mix containing minimum paste content should be
cohesive, free from segregation and bleeding.

19.  Minimum paste contents is determined from Flow table
test (carry out for workability)
Excess 10% voids content
19

20. Fifth step: Determination of Paste Content:-
20
CHAPTER-7

21. Weight of Aggregates:-
21

22. Sixth step: Cement and water content:-
For M20 grade concrete keeping in mind the target
mean strength suitable water-cement ratio is fixed as
per trial mixes.
 W/C ratio = 0.56
22
CHAPTER-9

23. Final Mix proportions for M20 grade concrete:-
23

24. Following the above procedure all the ingredients of concrete were
obtained for 5%, 10% and 15% in excess of paste content and water
cement ratio 0.56 and 0.58, the values are presented in Table .
24

25. CHAPTER-8
Conclusion:-
• The packing density value will remain same irrespective of grade of concrete.
• In packing density method, paste content in excess of void content will
increase with the increase in grade of concrete.
• In case of packing density method water cement ratio decreases with increase
in grade of concrete.
• The water and cement content for packing density and IS code method is
nearly same for any particular grade of concrete.
• The workability of concrete achieved is more in packing density method
compared to IS code method for the same grade of concrete, as the water
cement ratio is slightly higher in packing density method than IS code
method.

26. References
• [1] Wong, H. C. H. and Kwan, K. H. A., “Packing density: A key concept for mix
design of high performance concrete”.
• [2] Wong, H. C. H. and Kwan, K. H. A. (2008) “Packing density of cementitious
materials: part 2 – packing flow of OPC + PFA + CSF”. Materials and structures,
41:773 – 784.
• [3] Fennis, S. A. A. M. and Walraven, J. C. (2008) “Measuring the packing density to
lower the cement content in concrete”.
• [4] Wong, H. C. H. and Kwan, K. H. A. (2008) “Packing density of cementitious
materials: part 1 – measurement using a wet packing method”. Materials and
structures, 41:689-701.
• [5] Indian standard code of practice for, “Specification for 53 grade ordinary Portland
cement”, IS 12269 – 1987, Bureau of Indian Standards, New Delhi.
• [6] Indian standard code of practice for, “Specification for coarse and fine aggregates
from natural sources for concrete”, IS 383 –1970, Bureau of Indian Standards, New
Delhi.

27. References
• [7] Indian standard code of practice for, “Concrete admixtures – specification”,
IS 9103 – 1999, Bureau of Indian Standards, New Delhi.
• [8] Indian standard code of practice for, “Methods of test for aggregates for
concrete”, IS 2386 (Part III) – 1963, Bureau of Indian
• Standards, New Delhi.
• [9] Indian standard code of practice for, “Methods of sampling and analysis of
concrete”, IS 1199 – 1959, Bureau of Indian Standards,
• New Delhi.
• [10] Indian standard code of practice for, “Concrete mix proportioning –
Guidelines” IS 10262 – 2009, Bureau of Indian Standards, New
• Delhi.
• [11] Indian standard code of practice for, “Methods of tests for strength of
concrete”, IS 516 – 1959, Bureau of Indian Standards, New Delhi.

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