Delft University of Technology
Stereological Methods In Cement-Based Materials TechnologyA Survey Of My Research Group’s Activities During The Past Half Of A CenturyStroeven, Piet
DOI10.5566/ias.2207Publication date2019Document VersionFinal published versionPublished inImage Analysis and Stereology
Citation (APA)Stroeven, P. (2019). Stereological Methods In Cement-Based Materials Technology: A Survey Of MyResearch Group’s Activities During The Past Half Of A Century. Image Analysis and Stereology, 38(3), 201-211. https://doi.org/10.5566/ias.2207
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Image Anal Stereol 2019;38:201-211 doi: 105566/ias.2207 Communications
201
STEREOLOGICAL METHODS IN CEMENT-BASED MATERIALS TECHNOLOGY A survey of my research group’s activities during the past half of a century
PIET STROEVEN Faculty of Civil Engineering and Geosciences, Delft University of Technology, Delft, the Netherlands e-mail: [email protected] (Received June 23, 2019; revised October 27, 2019; accepted October 27, 2019)
ABSTRACT
Four topics of high engineering relevance in which we were involved are introduced herein. Aggregate packing in concrete is of obvious relevance: denser packings lead to reduced cement demands, while modern developments in the (super) high performance range of cementitious materials are based on particle packing. Fiber reinforcement efficiency in concrete that we have studied extensively offers a relatively simple stereological problem for which Cauchy laid down the fundament. In the third problem of damage analysis the dispersion of small cracks in concrete is at issue. Insight into damage characteris-tics would be relevant in all (fracture) mechanical experiments. This topic can equally be linked to Cau-chy. In both cases, the data acquisition by stereological methods is indicated. The fourth topic is of high actual relevance. It involves porosimetry in computer-simulated (virtual) cementitious materials, ultimate-ly aiming permeability estimation. The stereological problems involved are indicated, and - again – Cauchy can be linked to finding solutions. Finally, new, mostly yet unpublished developments are indi-cated aiming for more economic procedures as well as improving reliability of permeability estimates by nano-packing of globules, so that ultimately this methodology could replace the laborious and expensive (and biased) experimental route.
Keywords: Cauchy, aggregates, fibers, cracks, pores
INTRODUCTION
This paper is intended as a “farewell message” to my dear colleagues and friends in the ISS community, focusing on what I personally learned in this ISS community and showing to which engineering problems I applied it in the concrete technology world during the past half of a century. Hence, I herewith want to show my gratitude to the very community: it enriched my life, as a concrete technologist and as a human being!
I enjoyed my first experiences with STEREOLO-GISTS in the ISS community during the Bern conference in 1971. I was involved in an extensive study in the concrete materials field for my PhD study that I completed in 1973. For most PhD committee members out of “my” field, the 329 pages of my dissertation were probably outside their capabilities, and the stereological approach made this an even more serious problem. Although I received my PhD degree –yet not without some overt animosity– for my colleagues in Delft I was considered for the rest of my
active life an outsider who always knew better… As a consequence, the appointment in 1997 to professor was due to cooperation partner Beijing Jiaotong University in China, not to my home institution…
So, I figured that as a young Dr. I should convince colleagues that stereology was a powerful tool for solving practical engineering problems in the field of concrete technology. A highly relevant field was steel fibre reinforced concrete (SFRC), which presented the simplest stereological conditions I could imagine: dispersed lineal elements in space. This task was supposedly easier than doing so for the damage analysis problems I had faced earlier in my PhD study. Motivation to accept this mission was also coming from serious violations to stereological concepts I had discovered in both fields.
Looking backwards, the research efforts in the previous period involved four major engineering topics with stereological background. The two selected ‘promotion’ topics (SFRC and damage analysis) are nowadays quite established. Other contributions came from all over the world. The ‘French school’ can
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y due to sawirealcrete.
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decades late. In doing sthe grains coxperimental ds were found
oeven, 1973, ven, 2012).
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he nearest nei200 mm sam
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203
ggregate; (lefr 4~8 were se
ter on so, the
ould be data as
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curately
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Fig. 5. S-V cuof composite pGuo (1988) wget an even bfrom an exp2006).
Of coursento the (supeexceeding th
particle packphysical (vanMore materialpacking of paralready proodiscussed subj
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der Waals) l developmenrticles. Howef the relevaject.
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Herein
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centuries lanalysis metho
Our firstmethod involv
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ig. 6. (bottompecimen of 70ne grids.
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2'L AP L
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L FIBRE CRETE
rmulated in nology. The oe problem” isould readily pression by we analyzed
is the avera
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f the image. Sater his direodology that i
t applicationved the anar types in SFght (w/c=0.4 e aggregate ximum grainmodulus (FM
m) X-ray radio0x200x1000 m
el fiber reis well as theadditional fibfibers in orCauchy conce
planes is paralndicular to it a
It was foundased on the so
L
REINFO
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be transforwhich fiber
age number
fiber projectio6. Further, Lular to the grSaltikov propcted (and rais making use
n of the Balysis of theFRC. Two w
and 0.6) an(f=3.27 and
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inforced 3-e splitting tenber dispersionrthogonal seepts (Cauchyllel to the fraand parallel td, as an examo called Stroe
STROE
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em relevant ement of the troeven and Hrmed into tdistributions
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of intersectio
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Buffon/Saltike dispersion water to cemend two finene
f=3.89), we8 mm. Note thmpirical figu
“vertical sliceompaction by
point bendinsile tests wn characteristctions. This
y, 1882). Oneacture plane, tto the bottommple, that fibeven concept
EVEN P: Stere
204
for so
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(1)
ons
ray otal per han ants
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e” (totaling 10y gravitation w
ing ere tics
is e of the
m of ber (in
this cfiberstensil(Fig. See, otherreinfo
Nin sp
eological meth
ned by addinn aggregate rees, and dividimens, measurolled testedved from thet of about ted from eacVisualizationottom) of pying orthogoneven, 1979c
even and Da; Stroeven ang other thinorcement effindered possvior of the SF
The remainining experimegth tests in eiific informatiibution parameven, 1979c
even and Da).
0 in this case)was in vertica
case a mixturs), was directle strength at7) (Stroeven
e.g., Stroever relevant corcement in c
Note further tpace and in
hods in cemen
ng the total petained on eacing the sum
uring 70x200d to beyon
testing machequally size
ch full-size sn was by waypre-loaded cnal grids. For; 2009; Stro
alhuisen, andnd Słovik; Sngs, it proviiciency of theible to inte
FRC specimen
ng prisms weents and the cither one of oion on crack
meters of the ; 2009; Stro
alhuisen, 199
) of a test-loaal direction. A
re of 2D and tly reflected bt increasing vn and Babut,n (2009) for ontributions
concrete.
that in SFRC n the forthco
nt-based mater
ercentages ofch of a specif
m by 100. A 0x1000 mm, nd ultimate,hine and sectied prismaticspecimen (Fy of X-rayingconcrete sper detailed infooeven and S
d Stroeven 1Stroeven andided informae different fiberpret phenoens in structur
ere subjectedcubes to spli
orthogonal dirk developmen
full-size speoeven and S
96; Stroeven
aded (and craAnalysis is by
3D “randomby anisotropyvolume fracti, 1986; Stroea large selecto the fie
C we deal withoming dama
rials
f the samplefied series of
total of 48 were strain- thereupon ioned so that c specimens ig. 6 at the
g slices (Fig. cimens and ormation see Shah, 1978;996; Babut,
d Hu, 2007).ation on the ber types and menological ral terms.
d to 3-point itting tensile rections. For nt and fiber ecimens, see Shah, 1978;
and Babut,
acked) SFRC y orthogonal
mly” oriented y in splitting ion of fibers even, 1993). ction of also ld of fiber
h line length age analysis
Image Anal Stereol 2019;38:201-211
205
approach with surface area in space. Cauchy provided the relationships that are at the basis of counting observations and determination of total line length (SFRC) and total surface area (Damage analysis), respectively (Cauchy, 1882).
Fig. 7. Anisometry in steel fiber dispersion (top) and anisotropy of splitting tensile strength fs in N/mm2 of steel fiber reinforced cubes at increasing fiber volume fraction Vf (bottom).
For the fibre case of Fig. 6, upon application of the Stroeven concept of a mixture of 2D and 3D fibre portions, the following equation is obtained (Stroeven, 1979c; 2009)
' 1 2 1
2 2V VL L
(2)
where is the total length ratio of the 2D fibre portion over that of the total amount of fibres. Mono-size fibers are assumed in this case, however, also for multi-size and curved fibers, similar models have been expanded. In eq. (2), LV is the total fiber length per unit of volume and LV’ the component in the plane of the 2D portion; so, in the case of Fig. 6 oriented perpendicular to the compaction direction of the prismatic specimen. Consequently, it is the effective part of the fiber reinforcement because loading direction will be perpendicular to the plane of the X-ray image.
DAMAGE ANALYSIS
Buffon/Saltikov provided also the basis for quantitative analysis of cracks in concrete. By as well adopting the Stroeven concept for spatial crack development (combining at maximum, 1D, 2D and 3D portions), the orthogonal measurements of intersections of line grids with the cracks can be interpreted in spatial terms. Fig. 8 concerns the case of direct compression, requiring only a 3D and 1D portion, the latter having its axis of orientation coinciding with that of the loading. Hence, the solution for the spatial interpretation of cracking can be based on a section parallel to the loading direction in which the orthogonal observations LP Pand LP suffice (Fig. 8, at the left).
In mathematical terms, it is found that the crack surface area per unit of volume, SV, is related to orthogonal measurements in the mid-section of the compressed specimen by
41
2V L LS P P
P (3)
In tension testing, a combination of 3D and 2D portions is required. Again, an axial section can be sampled by an orthogonal line grid. For methodological details and results of applications, see (Stroeven, 1973; 1979b; Stroeven and Słovik; Stroeven and He, 2011a; 2011b). Of course, any (fracture) mechanical investigation on cementitious materials can profit from the structural research efforts discussed herein, since it will promote the understanding of the recorded phenomenological behavior.
Note that these labour-intensive contributions to the aforementioned topics had to be terminated at the end of last century, because physical experimenting became too expensive. Therefore, I figured we should instead use modern computer facilities. So, the last subject is hot, actual and highly relevant. My PhD student and son, Martijn, developed the first professional Discrete Element Method (DEM) - SPACE - in our group that became operational around the millennium break (Stroeven, M., 1999). During the next years, a series of my PhD students have used it (and an upgraded version, HADES) in studies on virtual cementitious materials (compucrete). Particle packing problems (as discussed earlier) and particularly permeability estimation were the issues of interest and engineering relevance.
0
4
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NA observed
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0
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ig. 8 (right) Pmall cracks vcomplete, ce
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In Stroevlaborated onereological r
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have expliciHowever,
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our engineeri
EABILITY
pts for 3D atural analysis. More recenand predicti
oeven 2017aose, our virtulement MethAddition (RSd in concrbiased partiep is hydratiegrated Partipherical cemeted grains (aspart from int
206
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ed prismatic cent spray. (lsections). Or
cle interferenand Scrivene
9. Simulated
concrete specleft) Manuallyrthogonal line
nces (Navi aner, 2005) (Fig
hydrated blen
cimen reveally copied crace grids are su
nd Pignat, 1g. 9).
nded cement
s myriads of ck pattern of uperimposed
996; Pignat,
paste
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Fig. 10. (tpaste with300 m2/kgcomplex psystem afteM., 1999).
Pore tby DRaMStructuringdevelopmeand pore s(SVM), insalso the In
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9;38:201-211
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on 2x105 “raubes. The sme sizes by SVrk analysis, ty (Stroeven aet al., 2017s visualized
207
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ucture of cemd mono-size crowth mechy XIPKM; (bglobules. Amhe two cases.
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208
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Hence, my ged with fulrimenting in he very laboysis problemgn counter-py years in erence procee
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oncrete is intie fiber topic mining the l
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hardened cemules dispersed
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SIONS
“stereologicall ambition the framewor
orious particlms in concretparts on SFR
a couple edings and iny thousand
n to show stefor solving enon this topic y of Techno
ui, 2001). Of imately relate(due to the
ength of a liace, by av
ll topics - asesulted in seuch as in IAS; Hu and
ong others wrand new devas simulating ment paste cd in fractal-ligists! Yet, r
to economation using oned in this pvik).
ally be stresd topics werethose years. ned here, bec
n of “hard” tem the discusssustainabilit
t la letter”. ASri Lanka wile laboratoryof cooperatio
with Viete Dutch Gochanges in th
accepted projetive was to rPortland cem
nt-based mater
al life” startinto extensi
ork of my PhDle packing ate) and ther
RC. It resulteof hundred
in journals inds available ereology a vengineering prwas Shui Zh
ology who rf course, damed in stereolotwo Cauchy ine or area o
veraging of
s already meeries of pubS (Stroeven, Stroeven, 20
with Kai Li, velopments ca
the outer hydconsisting oike “arms” (Frecently, we
omic develo– again – Ca
paper (see als
ssed that thee not the onlAt least, one
cause it may oechnology acsed topics. Tty aspects
Application foith Architect
y research waon with Tanztnam. The overnment (he country reect) in signifreduce CO2 e
ment by fine-
rials
ted when I ive physical D study (i.e.and damage reupon with ed over the
papers in n the SFRC worldwide),
ery practical roblems. My honghe from received his
mage analysis ogical terms concepts of
of a surface, their total
entioned for blications in et al., 2012; 006). Some
are still in an hereby be dration layer
of nano-size Fig. 11); real
have given opments in auchy’s 3-D
so: Stroeven;
e mentioned ly ones that e other topic offer nuance ctivities that
This one was in concrete ocussed on a tural student as conducted zania, Brazil
latter was (1982-2002), sulted in our
ficant budget emissions by grained rice
Image Anal Stereol 2019;38:201-211
209
husk ash (Bui, 2001) or non-commercial metakaolin (Vu, 2002). Mind that this was significantly before such CO2 emissions were internationally declared leading to global warming, hence it was hard in our case to find moral and, particularly, financial support. Note that the given examples are particle packing-driven. This illustrates again the actual relevance of the first topic discussed herein!
At the final end of this paper it should be men-tioned that promotion of stereology in my field was also explicitly in my mind during the many years that I participated in the ISS community as “regional representative” and as Editorial Board member for Acta Stereologica and Image Analysis and Stereology.
REFERENCES
Bui DD (2001). Rice hush ash as a mineral admixture for high performance concrete. PhD Thesis Delft Univ. Techn , Delft, the Netherlands.
Carcassès M, Ollivier JP, Ringot E (1989). Analysis of microcracking in concrete, Acta Stereol 8(2):307-127.
Cauchy A (1882). Mémoires sur rectification des courbes et la quadrature des surfaces courbes. Univ Press, Cambridge, UK. (in French).
Dequiedt AS, Redon C (2001). Some fields of application of automatic image analysis in civil engineering. Cem Concr Comp 23:157-69.
Erdogan ST, Quiroga PN, Fowler DW, Saleh HA, Livingston RA, Garboczi EJ, et al. (2006). Three dimensional shape analysis of coarse aggregates: new techniques for and preliminary results on several different coarse aggregates and reference rocks. Cem Concr Res 36:1619-27.
Garboczi EJ, Bullard JW (2004). Shape analysis of a reference cement. Cem Concr Res 34:1933-37.
Granju JL, Ringot E (1989). Amorphous iron reinforced concretes and mortars, comparison of the fiber arrangement. Acta Stereol 8:579-847.
Gundersen HJG et al. (1988). Some new and efficient stereological methods and their use in pathological research and diagnosis. Acta Pathol Microbiol Immun Scand 96:379-94.
Guo W (1988). Some material parameters on numerical statistical continuum mechanics of concrete. TU Delft Report 25-88-38, Delft.
He H, Stroeven P, Pirard E, Courard L (2015). On the shape simulation of aggregate and cement particles in a DEM system. Adv Mat Sci Engrn, Art ID 692768, 7 pages.
He H, Stroeven P, Stroeven M, Sluys LJ (2011a). Influence of particle packing on fracture properties of concrete. Comp Concr 8(6):677-92.
He H, Stroeven P, Stroeven M, Sluys LJ (2011b). Influence of particle packing on elastic properties of concrete. Mag Concr Res 64:163-75.
Hu J, Stroeven P (2006). Shape characterization of concrete aggregate. Image Anal Stereol 25:43-53.
Jennings HM (2000). A model for the microstructure of calcium silicate hydrate in cement paste. Cem Concr Res 30:101-16.
Jennings H M (2008). Refinements to colloid model of C-S-H in cement: CM-II. Cem Concr Res 38:275-89.
Kak AC, Slaney M (2001). Principles of computerized tomographic imaging. SIAM, Philadelphia.
LaValle SM, Kuffner JJ (2001). Randomized kinodynamic planning. Int J Robotics Res 20(5):378-400.
Le LBN (2015). Micro-level porosimetry of virtual cementitious materials. Structural impact on mechanical nd durability evolution. PhD. Thesis, Delft Univ Techn, Delft.
Le LBN, Stroeven P (2012). Strength and durability evaluation by DEM approach of green concrete based on gap-graded cement blending. Adv Mat Res 450/451:631-40.
Li K (2017). Numerical determination of permeability in unsaturated cementitious materials. PhD thesis, Delft Univ. Techn, Delft.
Li K, Stroeven P, Le LBN (2015). Methodology for porosimetry in virtual cementitious composites to economically and reliably estimate permeability. Image Anal Stereol 34(2):73-86.
Li K, Stroeven P (2017a). Systematic research on compucrete can shed light on some contro-versal isseus in concrete technology. J Heron 62(1):47-59.
Li K, Stroeven P (2017b). Herons Fountain 18: 200 Years old Cauchy concept pointed the route to optimizing concrete porosimetry in virtual reality. J Heron 62(2):121-27.
Li K, Stroeven P (2018). RSA vs DEM in view of particle packing-related properties of cementitious materials. Comp Concr 22(1):83-91.
Li K, Stroeven P. Modern approach to surface layer modifications of hydrated cement for improving permeability estimates of virtual concrete. Adv Cem Res (submitted for publication).
Li K, Stroeven P*. Bridging the gap between structural levels in concrete technology - Principles of geometric averaging. J Mat Charact (submitted for publication).
STROEVEN P: Stereological methods in cement-based materials
210
Li K, Stroeven M, Stroeven P, Sluys LJ (2017). Effects of technological parameters on permeability estimation of partially saturated cement paste by DEM approach. Cem Concr Comp 84:222-31.
Navi P, Pignat C (1996). Simulation of cement hydration and the connectivity of the capillary pore space. Adv Cem Based Mats, 4(2):58-67.
Pignat C, Navi P, Scrivener K (2005). Simulation of cement paste microstructure, hydration, pore space characterization and permeability determination. Mat Struct 38:450-66.
Shui ZH (2001). Some aspects of low content mono- and hybrid-fiber reinforced cementitious composites. PhD Thesis Delft Univ. Techn., Delft, the Netherlands.
Stroeven M (1999). Discrete numerical modelling of composite materials – Application to cementitious materials. PhD Thesis Delft Univ. Techn., Delft, the Netherlands.
Stroeven P (1973). Some aspects of the micromechanics of concrete. PhD. Thesis, Delft Univ. Techn., Delft.
Stroeven P (1979a). Morphometry of fibre reinforced cementitious materials. Part II: Inho-mogeneity and anisometry of partially oriented fibre structures. Mat Struct 12(67):9-20.
Stroeven P (1979b). Geometric probability approach to the examination of microcracking in plain concrete. J Mat Sci 14:1141-51.
Stroeven P (1979c). Micro- and macro-mechanical behaviour of steel fibre reinforced mortar in tension. J Heron 24(4):7-40.
Stroeven P (1990). Some observations on microcracking in concrete subjected to various loading regimes. Eng Fract Mech 35(4/5):1775-82.
Stroeven P (1993). On simulation, image analysis and structural modelling of steel fibre concrete. In: Adv Techn, Elsevier Sc Publ. pp. 399-404.
Stroeven P (1994). Damage mechanisms in fibre reinforced concrete composites. In: Comptes rendus des neuvièmes journées nationales sur les composites, AMAC, France, Saint-Étienne, pp. 925-38.
Stroeven P (2009). Stereological principles of spatial modelling applied to steel fiber-reinforced concrete in tension. Amer Concr Inst Mat J 106(3):1-11.
Stroeven P (2012). Shape assessment in concrete technology by Fourier analysis. In: Brittle Matrix Composites 10. Woodhead Publ. Ltd, Cambridge and IFTR, Warsaw, pp. 233-42.
Stroeven P (2015). 50 Years’ focus on concrete – from meter- to nano-scale 1963-2013. MediaCenter, Rotterdam.
Stroeven P Probing pores by stars - An essential module in porosimetry and permeability estimation
methodology of virtual cement paste. J Heron (submitted for publication).
Stroeven P, Babut R (1986) Fracture mechanics and structural aspects of concrete. J Heron 31(2):29-43.
Stroeven P, Dalhuisen D (1996). Damage evolution characteristics of steel fibre reinforced concrete in direct tension. Eng Mech 3(4):273-80.
Stroeven P, Guo Z, Stroeven M (2007). Structural effects on meso- and micro-level of fibre concrete due to compaction by vibration. In: Experimental vibration analysis for civil Engineering structures, FEUP, Porto, pp. 1179-87.
Stroeven P, He H (2011a). Image analysis of cracks in concrete: methodology. Opportunities and pitfalls. Int J Design Ecodyn 6(2):145-61.
Stroeven P, He H (2011b). Numerical assessment of concrete damage. J Heron 56(3):123-40.
Stroeven P, He H (2011c). Impact of Brazil nut effect on concrete’s structure and its engineering properties. Chapter 7 in: Construction and building – Design, material and techniques (Ed. Sophie G. Doyle) Nova Science Publ., New York:179-94.
Stroeven P, He H (2012). Brazil nut effect and concrete: Entering terra incognita. J Heron 57(2):103-117.
Stroeven P, He H, Stroeven M (2011). Discrete element modelling approach to assessment of granular properties in concrete. J Zhejiang Univ Sci A 12(5):335-44.
Stroeven P, Hu J (2006). Review paper – stereology : Historical perspective and applicability to concrete technology. Mat Struct 39:127-35.
Stroeven P, Hu J (2007). Gradient structures in cementitious materials. Cem Concr Comp 29:313-23.
Stroeven P, Le LBN, Sluys LJ, He H (2012). Porosimetry by double-random multiple tree structuring in virtual concrete and Porosimetry by random node structuring in virtual concrete. Image Anal Stereol, 31(1):55-63 and 31(2):79-87.
Stroeven P, Li K (2016). Heron’s Fountain17: Size and shape revisited in the light of 400 years old Cavalieri principle. J Heron 61(1):57-67.
Stroeven P, Li K (2017). A modern approach to porosimetry of virtual cementitious materials. Mag Concr Res 69(23):1212-17.
Stroeven P, Shah SP (1978). Use of radiography image analysis for steel fiber reinforced concrete. In: Testing and test methods of fiber cement composites. Constr. Press, Lancaster UK, pp. 345-53.
Stroeven P, Słovik M Cauchy-based modelling in cementitious materials technology. Archives for Civil Engineering (Submitted for publication).
Image Anal Stereol 2019;38:201-211
211
Stroeven P, Stroeven M (1999). Assessment of packing characteristics by computer simulation, Cem Concr Res 29:1201-6.
Stroeven P, Li K, Le LBN, He H, Stroeven M (2015). Capabilities for property assessment on different levels of the microstructure of DEM-simulated cementitious materials. Constr Build Mat 88:105-17.
Vu DD (2002). Strength properties of meta-kaolin-blended paste, mortar and concrete. PhD Thesis Delft Univ. Techn., Delft, the Netherlands.