Presented at the XXIV Nordic Concrete Research Symposium in Stockholm, August 17-19, 2022.

1. Voids ratio of manufactured sand
– influence of test method, grain
shape and size distribution
Tor Arne Martius-Hammer 1), Rolands Cepuritis 2, 3), Stefan Jacobsen 2)
and Ola Skjølsvold 1)
1) SINTEF Community
2) NTNU Department of Structural Engineering
3) Norcem, Brevik
Paper presented at XXIV NCR, Stockholm 16.-19. August 2022

2. Background and Purpose
• MIKS-project: Research Council of Norway KPN project with the industrial
partners Norcem AS, Skanska Norge AS and Feiring Bruk with NTNU,
SINTEF and DTU (2016-2021, 17,5 mill NOK cash, 1 Post Doc, 1 PhD)
• This paper: Investigate and develop test to measure void space of
aggregate for the Particle Matrix Method (PMM) for concrete proportioning
• “gigantic work done in SINTEFS lab, presented in app. 10 minutes!”
• PMM presented in detail by Rolands Cepuritis later in this session – stay
tuned!
2(14)

3. Basics about aggregate void space
Bulk aggregate unit volume:
Minimum voidspace emin = 1- (rbulk agg/ragg particle )
Maximum packing = (1- emin) = Fmax
Aggregate > 0.125mm (= particles in PMM) in concrete unit volume:
Vmatrix
Vagg > 0.125mm
3(14)

4. sphericity
Shape effect on aggregate void space
(Powers 1968)
4(14)

5. 4 void space methods investigated –
all with «light compaction»
• EN 1097-3; Determination of loose bulk density and voids
• "Well" defined filling procedure to avoid compaction and segregation. Operator
dependency seems to be low. Easy to use.
• EPP 4C-”Eigen Packing of Particles for 4C packing” (DTI); Experimental determination of
eigenpacking
• Gives "light compacted" voids ratio. The "compaction" procedure seems not to be well
specified, which may cause uncertainty concerning operator dependency. Seems easy to
use.
• New Zealand Flow Cone. Includes also possibility of friction assessment
• Several authors have confirmed good correlation between the flow time and flowability of
corresponding mortars. Seems easy to use and the operator dependency seems low.
• Norbetong method; Prosedyre for bestemmelse av pakningsgrad tilslag
• Easy and practical. Uses water to measure voidspace. Filling procedure as in
EN 1097-3 applied in this work due to uncertainty concerning operator
dependency. Lack of experience
5(14)

6. NZFC EPP and NorBet EN 1097-3
All four tests were run with 3 parallel specimens with
consistent results / very low scatter
6(14)

7. Materials used:
4 sands 0-4 mm in 3 gradings (GSD)
 "Årdal": Natural rounded (glacial deposit)/crushed; 60/40; "Årdal 1, 0-8
mm", as reference. Mean particle circularity of 0.84 (measured on the
0,125-4 mm fraction)
 "Velde": Crushed Granite "Velde Industri, 0-8 mm". Mean particle
circularity of 0.80 (measured on the 0,125-4 mm fraction)
 "Lørenskog": Crushed Gneiss/Granite "Lørenskog 0-8 mm". Mean particle
circularity of 0.77 (measured on the 0,125-4 mm fraction)
 "Lørenskog VSI": Crushed Gneiss/Granite" Lørenskog VSI 0-8 mm".
Mean particle circularity 0.81 (measured on the 0,125-4 mm fraction)
7(14)

8. Shape and Specific Surface Area (SSA)
Dynamic Image Analysis CAMSIZER P4 (ISO 13322-2), red
camera for larger particles, blue (zoom) camera for smaller particles
SSA was calculated from Grain Size Distributions (GSD) 8(14)

9. The 3 gradings of each sand
9(14)

10. A few results: void space for different
aggregates, gradings and methods
10(14)

11. Shape - void content
11(14)

12. GSD (by SSA) - void content
12(14)

13. Conclusions
Even small differences in filling/compaction procedures give
considerably different voids content, but the differences seem not to
be clearly influenced by neither GSD nor grain shape (sand types).
Decreasing circularity and increasing SSA increase void content, the
influence of circularity is more pronounced at high SSA
A moderate SSA increase from a low value (here from 7.9 to 11.3
mm2/mm3) does not clearly influence the voids ratio.
13(14)

14. Acknowledgements
The work was part of the MiKS project – Mikroproporsjonering med Knust Sand
(Norwegian for Microproportioning with Crushed Sand). MiKS is a competence
project for the industry funded by the Research Council of Norway, contract No.
247619, and the industrial partners Norcem AS, Skanska Norge AS and Feiring
Bruk with NTNU, SINTEF, DTU and NIST as research partners and NTNU as project
leader. The authors would like to thank the research council and the industrial
partners for their financial support and for facilitating the interaction between
research and industry.
14(14)