Robert Zimmerman, 560709-0270
Aggrregate quality and prospecting
Bilaga A
AGGREGATE QUALITY AND PROSPECTING
S P E C IF IC A I M
P A RT 1. T IL L
The aim of this project is to develop methods for
characterization of aggregate quality, for use in
prospecting for both rock mass and till deposits that
would, if exploited, yield good quality aggregate.
The methods should be easily implemented and
interpreted. Thus, these methods will be important
tools in assisting the selection of the best site
available in the local area of an engineering
construction for aggregate production. This requires
a suite of interrelated studies that attack the subject
of aggregates from different disciplines. The project
is divided into four parts. Part 1 - till properties as
an indicator of the potential quality of local bedrock
as aggregate; Part 2 - development of a geophysical
methods for interpretation of frequency of
horizontal or sub horizontal discontinuities in the
rock mass; Part 4 - geophysical characterization and
occurrence of coarse grained and thick deposits of
till; Part 3 - Image Analysis to determine aggregate
size and shape distribution and for interpreting the
Los Angeles and Micro Deval tests. A future
project will deal with testing the prospecting
potential of the methods developed in this project.
I N TRO D UC T IO N
AND
B A C K G RO U N D
The source of aggregates is changing from natural
to crushed rock. This has lead to several difficulties.
Our present day standards are often based on the
knowledge gained from decades of use of natural
aggregates. However, crushed aggregates do not
have the same characteristics as natural aggregates.
Thus, there is a need to be able to quantitatively
characterize the quality of aggregates. The choice of
a rock quarry is dependent upon the rock quality
and its potential usage as aggregate material. Since
most bedrock in Sweden is covered by Quaternary
sediments, bedrock maps can be misleading. New
methods are needed that aid in the best choice of
placement of a rock quarry. The better the rock
aggregate, the longer will be the life of engineering
products, and the lower will be the demand for
aggregates – thus, fewer and smaller quarries will be
needed. It is both economically and environmentally important that new and better methods for
aggregate quality and aggregate prospecting are
developed.
P RO P E RI T IE S V E R S U S
A G G RE G A TE Q UA LI TY O F LO C A L
B E D RO C K
Introduction – Till varies greatly in composition,
grain-size distribution, and boulder content, as well
as petrographic composition. The size, shape and
frequency of the coarse particles should be
dependent on the rock-mass quality. The fractures
in the rock play a very important role in glacial
erosion. The boulders transported away from the
source rock are broken and crushed to finer
particles; the size decreases with increased distance
from the source. Till is primarily composed of local
bedrock material and is transported only a few
kilometers. Thus, a study of the till will give
important information about the local rock mass,
and can be used to determine its quality with respect
to suitability as aggregate material.
The aim – of this part is to determine a
relationship between till properties and potential
aggregate quality of the local bedrock.
Theoretically, the size, shape, and frequency of till
cobbles and boulders should be related to the
bedrock composition and fracture frequency. Strong
rocks with few joints should yield many large
boulders, whereas weak rocks with numerous joints
should yield smaller boulders. Also, the mineral
composition and grain shape of the silt-to-gravel
fraction of the till will represent the crushed rock
mass. Furthermore, the percentage of coarse versus
fine particles should be related to the physical
properties of the local bedrock. Strong rocks
produce coarser till, whereas weaker rock produces
clay-rich till. Thus, samples from the local till can
give important information about the potential
aggregate quality. This can be difficult to determine
from just a few isolated drill holes in the rock mass.
The composition of the till can allow us to detect
the occurrence of unwanted rock mass.
Boulder size and frequency will be studied and
correlated to the rock mass strength and fracture
frequency of the local bedrock (associated with
parts 2 and 4). The silt-to-gravel fractions in the till
will be studied to determine the predominant
mineralogy and particle form (Lindqvist et al., 2001,
2003; Åkesson et al., 2001a,b). It will be possible to
determine if the local rock mass, when crushed, will
produce extensive free mica, free quartz, clay
minerals, alkali-silica reactive minerals or particles
shapes which are not optimal for high quality
aggregates.
Robert Zimmerman, 560709-0270
Aggrregate quality and prospecting
Field study – Three sites will be chosen, in
cooperation with the Swedish Geological Survey
Rock Quality Map project, where the bedrock is
expected to yield aggregates of different qualities:
very good, moderate, very poor. We will study both
the bedrock and the till down-ice from the rock
outcrops. The till will be studied in three areas,
down-ice, from the rock outcrop. The primary
target of the study is the petrography, size, shape
and frequency of the boulders on the ground
surface. Secondly, the till matrix composition will be
determined, including mineralogy, grain-size and
grain-form distribution.
The till boulders – will be evaluated with respect
to petrography, to determine which percent
originates from the local bedrock or from a more
distal source. The microstructures will be studied in
thin sections (Lindqvist et al., 2001, 2003; Åkesson et
al., 2001a,b) and related to LA and MD values. In
association with Part 4, the size and shape of the
particles will be determined, and LA and MD tests
preformed, using EU standard methods and
Fernlund’s 3-D IA method (Fernlund, 2005a,b,c).
In association with Part 2, the local bedrock
composition and fracture frequency will be studied.
This will allow an evaluation of the till properties
with respect to the properties of the local bedrock.
The till matrix – We will study the mineralogy,
microscope analysis, of the till matrix and compare
this to the bedrock petrography. We will especially
check for reactive minerals such as sulfates and
strained quartz and % free mica.
Study of the bedrock – The bedrock composition
and fractures will be studied, in association with
Part 2. The resistance to impact and wear, LA and
MD values, will be determined, in association with
Part 4.
P A RT 2. F RA C TU RE
F RE Q U E N C Y O F
RO C K S
Introduction – The fracture frequency of rocks can
be assessed on rock outcrops with different
techniques. It is difficult, however, to assess
horizontal fracture frequencies from the surface of
the rock outcrops. The frequency of horizontal
fractures downward in the rock mass are not
observed; instead, their frequency is normally
estimated. The intensity of fracturing is related to
several physical properties of the rock: electric
resistivity,
seismic
sound
velocity
and
electromagnetic wave velocity (Zimmerman and
King, 1985; Zimmerman et al., 1994; Zimmerman
and Main, 2004). At present there is no established
correlation between fracture frequency and
aggregate qualities. This should be able to be
determined by applying several geophysical methods
Bilaga A
that indirectly measure rock fracture frequency. In
connection with aggregate production, a depth
range up to ca 10 meters is sufficient.
The aim – of this project is to evaluate the threedimensional fracture frequency on outcrops using
window mapping, radar measurements and electromagnetic resistivity measurements.
Methods – To establish the possible correlation
between results of geophysical methods and
fractures a study of vertical sections is needed.
Horizontal fractures can be observed in the vertical
section; thus, we can assess how well the methods
detect horizontal fractures. Suitable localities would
be road cuts and rock quarries. Localities with
variable fracture frequency, from strongly fractured
to sparsely fractured, will be studied. Lithological
features that affect physical properties will be
analyzed in thin section. This includes the content
of conductive minerals like graphite and sulphides,
and the mica content. At each site the fracture-fill
minerals will be identified, and several cores of unfractured rock will be taken to provide a reference
for interpretation of the various physical properties.
The design of the geophysical measurements has to
take into account the sampling bias caused by
structural anisotropy and by the orientation of
fracture sets. This project will be carried out in close
cooperation with Raicon Malå Geoscience AB
regarding the radar aspect of fracture frequency
estimation.
The field studies of the bedrock will include fracture
mapping on a horizontal surface and a vertical
surface (road cut). Several geophysical tests will be
made: seismic, geo-radar, geo-electric and gamma
ray spectrometry. New geo-radar methods will be
tested on the horizontal surface. The geo-radar
measurements can facilitate a 3-D fracture
frequency assessment when combined with surface
estimates. We hope to determine the occurrence of
nearly horizontal joints and fractures which are very
important, since they define the third dimension of
potential blocks that can be plucked by the ice. The
gamma spectrometer measurements allow a
determination of the uranium content and its
variance to assess the potential radon risk if the
aggregate is used in construction of homes. Finally,
electromagnetic and seismic measurements are the
tools that can be used in a prospecting situation to
characterize the bedrock to a certain depth (King et
al., 1988). The measurements made, in a wellcontrolled test, are used to calibrate the analysis
particularly aiming at rock quality aspects. Cores of
the rock will be studied in the lab for mineralogical
composition, microstructure and strength. LA and
MD tests will be made in association with part 4.
The results will be compared to the till
characteristics, in association with part 1.
Robert Zimmerman, 560709-0270
Aggrregate quality and prospecting
P A RT 3. G E O P HY SIC A L
IN V E S T IG A TIO N S F O R
D E T E R M IN A T IO N O F C O A R SE G RA IN E D
A N D TH IC K D E P O S I T S O F TI L L
Introduction – The size distribution of the till mass
as well as the thickness of the till is difficult to
determine from surface analysis. In order to be
suitable as a source of aggregate the till should have
a high proportion of coarse particles as well as be
sufficiently thick so that excavation is both
economically and environmentally feasible. This
project will apply geophysical methods to study
both the composition and thickness of till deposits.
The aim – of this project is to develop geophysical
methods to characterize till-types suitable for
aggregate production, resulting in a prospecting
method for coarse grained and thick deposits of till.
Methods – Geophysical measurements will be
made at sites with till of variable grain-size
distributions and thicknesses. To verify the results,
the till will be excavated. The geophysical
measurements, seismic, geo-radar, geo-electric, and
gamma spectrometry, will provide information
about the thickness and the physical properties of
the till. The till composition, petrography, size
distribution and mineralogy can be coupled to the
results of the geophysical measurements. Several
methods will be used in combination to constrain
the major geological features represented, i.e., the
depth to the water-enriched zone of the till and the
depth to the basement interface, which are expected
to be represented in the seismic, geo-radar, and geoelectric data.
Seismic – Refraction-seismic measurements are
required to obtain a precise measure of the depth to
the bedrock interface, which constrains the
interpretation of the geo-radar and geo-electric data.
Geo-electric methods – Characterization of the till
can be made using several methods based on
electrical resistivity variations. The clay content in
till, together with the variation of the content of
coarse material, is reflected in the electric resistivity.
The electric resistivity can indirectly be assessed
with both direct current measurements carried out
as 2D and/or 3D imaging/tomography and
electromagnetic methods operating with several
radio frequencies, such as radio-magnetotelluric
(RMT) measurements. The calibration of the
relation between clay content and resistivity can be
established by measurements of till with a large
variation of clay content (Al-Mjeni et al., 2002).
Geo-electric methods can also be used to determine
the thickness of the till above the bedrock as well as
the occurrence of zones where groundwater is
abundant. More reliable results can be achieved,
however, by combining these with other
Bilaga A
geophysical methods such as refraction seismics
(e.g., King et al., 1988).
Geo-radar – Measurements with geo-radar
technique should be tested to identify, in the
uppermost ten meters, any correlation between
patterns extracted from radargrams and till
properties. It is important to identify radargram
characteristics that are associated with coarsegrained till and its thickness.
Gamma radiation – Assessment of the uranium
content, which is associated with radon risk, is
essential. A correlation between the rock types and
the gamma radiation can be made by image analysis;
combining bedrock type, outcrops, and airborne
gamma radiation measurements using GIS. The
method requires strategies that admit fuzzy
boundaries and that can incorporate estimated
errors in aircraft position, in order to minimize the
variance related to rock types and to identify
varieties of the same rock type that may have
different uranium contents.
P A RT 4. E V A L UA T IO N
O F I MA G E
A N A L Y S I S ME T HO D A P P L I E D TO SIZ E
A N D S H A P E D I ST R IB UT I O N S A N D
E V A L UA T IO N O F T HE L O S A N G E LE S
A N D M IC RO D E V A L T E S T S
Introduction and general overview of the
subject – The new EU standards for railroad
aggregates include several tests, including size
distribution, shape and resistance to wear and
impact (LA and MD values). Theoretically,
Fernlund’s 3-D Image Analysis method (Fernlund,
2005,a,b,c) can replace several of the EU Standard
tests for roads and railroads. The size distribution
for all three axes of each particle can be determined.
All the shape tests can be carried out simultaneously
to the size distribution. Additionally, the method
can be used to evaluate the results of both the Los
Angeles and micro Deval tests. The IA test is very
fast and accurate. Only one test is needed instead of
numerous tests, and results yield detailed
information about individual particles and not just a
bulk value. This means that the quality of the
aggregate is more accurately determined than by the
traditional methods. In the future, standards can be
developed which require aggregates that are best
suited for a specific application. This will increase
the life expectancy of the engineering construction
and decrease the total demand of aggregates needed.
It can potentially be a dynamic tool in aggregate
quality control and prospecting. These results will
be useful for aggregate used in bound or unbound
form, as aggregate size and shape are known to be
key factors in controlling the mechanical properties
Robert Zimmerman, 560709-0270
Aggrregate quality and prospecting
of concrete (Zimmerman et al., 1986, Lutz et al.,
1997).
The aim – is to study the potential aggregates, from
Part 1, 2, and 3 - different types of rocks from
different places in Sweden, both with the EU
standard tests and Image Analysis test. The purpose
of this project is to compare the results and
determine if this new 3-D IA method is more
accurate, is better able to quantify the quality of
aggregates, and is more cost efficient.
Methods – Field-sampling sites will be those
studied in Parts 1, 2, and 3 from different regions
of Sweden. The aim is to test rocks that are
different with respect to their petrology and physical
characteristics. The choice of sites will be made
together with Mattias Göransson from Swedish
Geological Survey, SGU and with Jan Erik
Lindqvist from the Swedish National Testing and
Research Institute, SP, working with Los Angeles
tests and their correlation with petrography. The
size distribution, the shape aspects and surface
texture and angularity all will be determined both
before and after the LA and MD tests.
Tests to be done at KTH before and after the LA and
MD tests
Image analysis – is very simple and inexpensive. It
requires a digital camera, a box, sand and glow-inthe-dark beads. A 5 cm thick layer of sand is placed
in the box and covered with the glow-in-the-dark
beads. The particles are first imaged by laying them
on top of the beads in a dark room; in the field a
dark drop cloth is used. Then, the particles are
turned on end, by hand stuck into the bed of sand
and beads so the longest axis is perpendicular to the
sand bed and the smallest projected area is imaged.
Particles are not touching, and there is high contrast
between the background and the particles. Thus, no
preprocessing is required for the image analysis. The
results are very accurate. The images will be
analyzed using “particles” software (Wang, 1999).
EU standard tests will be done: Sieve analysis,
L/T index, grain shape, maximum grain dimension,
comparison to silhouette charts. Other tests to be
done include Weight, and Danish Box test.
The largest part of the project will be the evaluation
of the results. Statistical analysis will be conducted.
Each method will be evaluated.
Some of the important questions that need to be
addressed are:
 Sieve size and IA size are not exactly the same.
Fernlund (in prep) shows conversion of IA size to
sieve size is dependent upon the shape relationships
of the individual particles that govern whether or
not it would be retained on a sieve. The data
Bilaga A
obtained in this project will help us evaluate how
the particles pass or are retained on a sieve.
 The L/T index is a value that represents the
length-to-thickness ratio of the particle samples as a
whole. In contrast, with IA we can determine the
L/T ratio for each particle, and thus report the
frequency distribution with respect to all the
particles. We will evaluate the importance of such
detailed results compared to the traditional bulk
L/T index.
 How the IA measure of the longest dimension
compares to the longest dimension as measured in
true 3-D.
 The overall shape and angularity determined by
comparison to silhouette charts will be compared to
the Image Analysis 3-D shape and surface texture
analyses.
 How the increased information from the IA
evaluation can be compared to the LA and MD
values. To what extent is there a potential use of
this increased information.
P R E L I M IN A RY
RE SU L TS
Project coordinator Zimmerman has worked for
several years on image analysis of geological
materials, and its use in estimating physical
properties (Sisavath et al., 2001; Lock et al., 2002).
The correlation between fracture frequency and the
electro-magnetically resistivity has been studied for
strongly brecciated rocks at the Lockne impact
structure (Bäckström, 2004) and at the Björkö
structure (Bäckström and Henkel, 2003). The 3-D
fracture frequency calculation based on 2-D data
could be confirmed from drill cores.
Petrographic studies have shown that there is a
correlation between the LA value and the
microstructures in the rock. The research team at
SP has worked with image analysis and with
petrographic studies of microstructures in rocks
(Lindqvist et al, 2001, 2003, Åkesson et al, 2001a, b).
They have carried out Los Angeles and resistance to
impact tests on the rocks, and have suggested a
correlation between the LA value and the
microstructures.
Fernlund (2005a) gave a detailed presentation of the
new 3-D Image Analysis method for size
determination of coarse aggregates. Fernlund
(2005b) presented how the 3-D IA method can be
applied to shape determinations of coarse
aggregates. Fernlund (2004, 2005c) presented the
results of applying the 3-D IA method to the
evaluation of the Los Angeles Test. Fernlund (in
prep) describes the comparison of the size
distribution based on Image Analysis to sieve
analysis. This work shows that it is not necessary to
Robert Zimmerman, 560709-0270
Aggrregate quality and prospecting
accurately determine the mass of the particles, and
that the difference between these methods is due
solely to the how size is measured. “Size” with IA is
defined as the intermediate axis of the particle,
whereas for sieve analysis it is a complex
relationship dependent upon shape and size.
Fernlund (1998) showed that sieve analysis results
were highly dependent on particle shape.
P RO J E C T R E LE V A N C E ,
P A R TS
1-4
Part 1 – The bedrock in Sweden is almost entirely
covered by glacial sediments, predominately till.
Theoretically the till composition would be the
same as the local bedrock when crushed. If this
correlation is established, then the quality of the
bedrock can be determined from analysis of till, and
not be dependent upon a few drill hole core
analyses. The till composition should reflect the
average composition of the local bedrock, whereas
the drill cores are only pinholes in the rock mass.
This can be a helpful aid in prospecting for
aggregate sites. It will be possible to established if
the rock mass would produce unwanted minerals
such as reactive quartz and flaky mica. It is
important that the rock quarries produces aggregate
of high quality, and not lots of waste material.
Parts 2 and 3 – Increased use of detailed
geophysical measurements for applications in soil
and rock properties for prospecting is a new and
exciting subject. In the future it will be increasingly
important to locate aggregate sources at a low cost.
The existing methods are not sufficient; it is difficult
to quantify the quality of the rock mass based on
only a few isolated drill hole cores. It is
environmentally un-acceptable that quarries are
opened that yield poor quality aggregate and result
in extensive waste rock that will end up in land fills.
The geophysical methods will be an added tool in
identification of rock masses that potentially will
yield high quality aggregates.
Part 4 – The development of Image Analysis
methods provides a means to more accurately and
quantitatively describe the quality of aggregates. It is
economically important for our society that the
aggregates used in our engineering endure and
function for as long as possible. Environmentally,
there are two aspects that are enhanced by
exploitation of high quality aggregate. Firstly, if the
life expectancy of the construction is longer then
there will be a lower demand for aggregate, and so
fewer and smaller quarries will be needed. Secondly,
waste material is produced during the maintenance
and reconstruction process. If our engineering
constructions last longer, due to the use of higher
quality aggregates, the amount of waste material will
be decreased.
Bilaga A
Most of all, it is important for the aggregate
producer to be able to guarantee the quality of the
product. With the IA method being so easy and
inexpensive, more frequent tests can be made. Also,
the accuracy of the method is greater that of
traditional methods.
An added extra is that this method for size and
shape distribution can easily be carried out on site in
the field. Thus, it can be used as a control method
during construction. Samples do not need to be sent
to the lab for analysis and, due to its low cost, more
frequent tests can be made.
P RO J E C T
O RG A N I Z A T IO N
The project is designed as a PhD research student
project for four students, one for each part of the
project. The project coordinator will be Prof.
Robert Zimmerman, head of the Engineering
Geology and Geophysics group (EGG) in the
department of Land and Water Resources
Engineering at KTH. Other members of the team
will be Joanne Fernlund of the EGG group at
KTH; Jan-Erik Lindqvist at the Swedish National
Testing and Research Institute (SP); Torleif Dahlin
at the department of Engineering Geology, Lunds
Tekniska Högskola, Lunds Universitet; Herbert
Henkel at the EGG group at KTH; Mattias
Göransson, responsible for the rock quality maps at
the Swedish Geological Survey; Lars Stenlid at
Skanska’s aggregate laboratory; and Per Morén,
head of the aggregate group at NCC.
Joanne Fernlund will work actively in projects 1 and
4, particularly with the image analysis aspects and
the study of till.
Jan-Erik Lindqvist, together with Urban Åkesson
(also at SP), will work with the petrographic analysis
and the correlation between microstructures in the
bedrock and their LA and MD values, in parts 1 and
4.
Torleif Dahlin will work actively with the
geophysical studies, part 2 and 3. The geophysical
company ABEM has collaboration with Torleif and
will provide the geophysical instruments and
computer programs necessary for the project.
Herbert Henkel will work primarily with the
geophysics aspects, parts 2 and 3.
Robert Zimmerman, 560709-0270
COST
Aggrregate quality and prospecting
E S TI MA T E
The equipment for image analysis is not very
expensive (see table on right). It consists of a
computer, image analysis program, high-resolution
digital camera, a tripod, a drop cloth for making a
dark room around the sample and camera, and
some glow-in-the-dark beads. The tests: sieve
analysis, LA and MD tests, and hand measurement
of the particles for shape characteristics, are more
costly. Some of these tests can be done in
cooperation with NCC, Skanska, SP, and SGU in
association with their normal testing. The costs for
the tests are shown in the table to the right.
Sampling of rock material will require fieldwork for
documentation of the rock quarries and
transportation of the samples to the lab for detailed
analysis.
Bilaga A
Image analysis costs
Computer and IA programs
30 000
Camera
10 000
Tripod
1 000
Glow in the dark beads
2 000
Box and drop cloth for dark room conditions
Total
1 000
44 000
Laboratory tests
50 LA tests @ 2 600
125 000
50 MD tests @ 3 000
150 000
50 Petrographic thin section analysis @ 7 500
375 000
50 Sieve analysis @ 1 000
50 000
Total
700 000
C I TE D P UB L IC A T IO N S
Al-Mjeni, R., Günzel, F., Jing, X. D., Grattoni, C. A., and Zimmerman, R. W., The influence of clay fraction on
the complex impedance of shaly sands, Proc. 2002 Int. Conf. Soc. Core Analysts, Monterey, Calif., 20-23 Sept.,
paper A44, 2002.
Bäckström, A. A study of impact fracturing and electric resistivity related to the Lockne impact structure,
Sweden. In Ch. Koeberl and H. Henkel (eds) Impact Tectonics, Proceedings of the 8th workshop of the ESF program
IMPACT. Springer Verlag. pp. 389-404, 2004.
Bäckström, A. and Henkel, H., Geology and rock physical properties in the Björkö (Mälaren) area. Dep. Of Land
and Water Resources Engineering, Royal Institute of Technology Report to the Swedish Energy Agency,
2003.
Fernlund, J. M. R., The effect of particle form on sieve analysis: a test by image analysis. Eng. Geol., vol. 50,
pp. 111-124, 1998.
Fernlund, J. M. R., Image analysis method for evaluation of the Los Angeles Drum test, GFF, vol. 126, pp. 143144, 2004.
Fernlund, J. M. R., 3-D image analysis size and shape method applied to the evaluation of the Los Angeles test,
Eng. Geol., vol. 77, pp. 57-67, 2005a.
Fernlund, J. M. R., Image-analysis method for determining 3-D size-distribution of coarse aggregates, Bull. Eng.
Geol. & Environment, vol. 64, pp. 000-000, DOI: 10.1007/s10064-004-0251-8, 2005b.
Fernlund, J. M. R., Image-analysis method for determining 3-D shape of coarse aggregate, Cement Concr. Res., vol.
35, pp. 000-000, 2005c.
King, M. S., Zimmerman, R. W., and Corwin, R. F., Seismic and electrical properties of unconsolidated
permafrost, Geophys. Prospect., vol. 36, pp. 349-64, 1988.
Lindqvist, J. E., Snäll, S., Solyom, Z., and Schouenborg, B., Quantitative determination of quartz in aggregate
samples, in Aggregate 2001 -Environment and Economy, 2001.
Lindqvist J. E., Åkesson, U., Malaga, K., Schouenborg, B., and Göransson, M., Assessment of mechanical
durability properties of rock materials using quantitative microscopy and image analysis, SP Rapport 2003:06,
2003.
Lock, P. A., Jing, X. D., Zimmerman, R. W., and Schlueter, E. M., Predicting the permeability of sandstone from
image analysis of pore structure, J. Appl. Phys., vol. 92, pp. 6311-6319, 2002.
Lutz, M. P., Monteiro, P. J. M., and Zimmerman, R. W., Inhomogeneous interfacial transition zone model for
the bulk modulus of mortar, Cement Concrete Res., vol. 27, pp. 1113-22, 1997.
Sisavath, S., Lock, P. A., Jing, X. D., and Zimmerman, R. W., Use of image analysis to study the effect of pore
roughness on the hydraulic conductivity of reservoir rocks, Proc. 5th Nordic Symp. Petrophys. (Copenhagen, 1920 Aug. 1999), Nordisk Energiforskning, pp. 149-156, 2001.
Wang, W., Image analysis of aggregates, Computers and Geosciences, vol. 25, no. 1, pp. 71-81, 1999.
Robert Zimmerman, 560709-0270
Aggrregate quality and prospecting
Bilaga A
Zimmerman, R. W., and King, M. S., Propagation of acoustic waves through cracked rock, Proc. 26th U. S. Rock
Mech. Symp., A. A. Balkema, Rotterdam, pp. 739-45, 1985.
Zimmerman, R. W., and Main, I. G., Hydromechanical behaviour of fractured rocks, in Mechanics of FluidSaturated Rocks, Y. Guéguen and M. Boutéca, eds., Elsevier Academic Press, San Diego and London, pp. 363421, 2004.
Zimmerman, R. W., King, M. S., and Monteiro, P. J. M., Elastic moduli of mortar as a porous-granular material,
Cement Concr. Res., vol. 16, pp. 239-45, 1986.
Zimmerman, R. W., Myer, L. R., and Cook, N. G. W., Grain and void compression in fractured and porous
rocks, Int. J. Rock Mech., vol. 31, pp. 179-84, 1994.
Åkesson, U., Lindqvist, J., Göransson, M., and Stig, J., Relationship between texture and mechanical properties
of granites, central Sweden, by the use of image analysis techniques, Bull. Eng. Geol. & Environment, vol. 60,
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