KTH
Mark- och Vattenteknik
KTH / Department of Land and Water Resources Engineering / Research projects
Title...
Project leader: Joanne Fernlund
Participants: Björn Lagerblad, Weixing Wang
Key words: Characterisation of Geological materials, image analysis, laser analysis, aggregates, grainsize distribution
Project period: 2002 - 2006
Funder: Application for funding to the Swedish Research Council
Background
The goal of the project is to develop new methods for the characterization of geological materials. The
traditionally the methods used for determining the size distribution of geological materials has been
sieve or sedimentation analysis. These methods are easy to perform and have been used for many
years. However in truth they do not measure any dimension of any of the grains in an aggregate
material; they give a rough idea of the materials “size”. With the computer new possibilities have
arisen; image and laser analysis.
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Relevance
Image and laser methods entail detailed measure of numerous parameters of the individual particles in
a material. The detail is so great and the parameters so numerous that we have a new problem to face;
what is relevant and what is size? Size is not a simple quality but involves overall dimensions, irregular
shape, surface texture as well as weight. If you think of the size of a person the concept is somewhat
more simple than it is for particles of sand and gravel; your height and weight usually give a good
picture of your size. But this is not possible with particles that have irregular shapes. Some means of
classifying size and shape needs to be developed and furthermore these parameters should be relevant
for people in industry who use the aggregate in concrete, asphalt and other engineering applications
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Methods
Image analysis and laser scanning are the two main methods used in this project. The size of the
particles range from clay to cobble and even boulder size. For the fine grain sizes microscopes are
needed to obtain images of the particles otherwise digital cameras are sufficient.
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Material/Data bases
The results of the analysis are saved in data files. These are further processed and statistically
evaluated.
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Title...
Project leader: Joanne Fernlund
Participants: Lars Stenlid, Weixing Wang
Key words: Characterisation of wear by LA tests on railroad aggregates using image analysis
distribution
Project period: 2002 - 2003
Funder: Funding not confirmed
Background
Wear of aggregates for railroads is often tested using a LA drum (LA stands for Los Angeles). In general
aggregates are placed in a drum which is rotated for a certain number of revolutions after which the
aggregates are removed and sieved. The change in size reflects some measure of their resistance to
wear. This method uses sieve analysis twice: first to select the particles to be put in the drum and then
to evaluate their change in size. Sieve analysis however does not really measure the size or shape of the
particles, it only is an indirect measure of size.
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Relevance
Image analysis is to be used to measure the size, shape and surface texture of the particles both prior
to and after the LA drum test. Since image analysis can measure many parameters for each particle the
actual effect of wear will be able to be studied in detail. This is very important for aggregates used in
areas where wear is a prime concern such as is the case in railroad aggregates.
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Methods
Image analysis and Los Angeles milling tests
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Material/Data bases
The results of the analysis are saved in data files. These are further processed and statistically
evaluated.
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Partners
The above research projects have close contact both with Lars Stenlid at the Skanska aggregate lab in
Bålsta and Per Murėn, Vice president of technology Ballast at NCC.
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Publications/Presentations
This research project is still in the planning stage, funding has been applied for but not confirmed. The
past research in this field has resulted in the following masters, licentiate and doctorate thesis.
Passi Tolppanen, 2001, 3-D characterization and degradation analysis of rock aggregates, Doctoral
Thesis, Division of Engineering Geology, Department of Civil and Environmental Engineering,
Royal Institute of Technology.
Anna Klingberg, 2001, Variationer hos materialparametrar inom Balastindustrin, Licentiate thesis,
Division of Engineering Geology, Department of Land and Water Recourses Engineering, Royal
Institute of Technology.
Maria Teresa Font Jimenez, 2001, Influence of fine aggregate’s shape on mortar theology, Masters
Thesis, Division of Engineering Geology, Department of Land and Water Recourses Engineering,
Royal Institute of Technology.
Patrick Ebeling, 2001, Characterization of aggregate degradation by 3-D laser scanning, Masters Thesis,
Division of Engineering Geology, Department of Civil and Environmental Engineering, Royal
Institute of Technology.
Mattias Widenbrant, 2000, Sjölvkompakterande betong med bergkrossmaterial – kornformens inverkan
på betongens reologi, Masters Thesis, Division of Engineering Geology, Department of Land and
Water Recourses Engineering, Royal Institute of Technology.
Sabina Hassenruck, 1999, Influence of aggregate shape on fresh concrete rheology, Masters Thesis,
Division of Engineering Geology, Department of Land and Water Recourses Engineering, Royal
Institute of Technology.
Joanne Fernlund, 1988, The effect of particle form on sieve analysis, a test by image analysis,
Engineering Geology 50, 111-124.
Lennart Ljungström, 1998, Image analysis of road surfaces, Licentiate Thesis, Division of Engineering
Geology, Department of Land and Water Recourses Engineering, Royal Institute of Technology.
The picture is of railroad aggregates.
Sidansvarig: Mark- och Vattenteknik, KTH, Infomaster@aom.kth.se
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The picture is of railroad aggregates.
Sidansvarig: Mark- och Vattenteknik, KTH, Infomaster@aom.kth.se