The hydration of an Ordinary Portland Cement (OPC) and the influence of selected polymers [Elektronische Ressource] : a mineralogical study using an external standard method for quantitative X-ray diffraction = Die Hydratation eines Portlandzementes und der Einfluss ausgewählter Polymere/ Daniel Jansen. Betreuer: Friedlinde Götz-Neunhoeffer

De
The hydration of an Ordinary Portland Cement (OPC) and the influence of selected polymers: A mineralogical study using an external standard method for quantitative X-ray diffraction Die Hydratation eines Portlandzementes und der Einfluss ausgewählter Polymere: Mineralogische Charakterisierung mittels einer externen Standard Methode zur röntgenographischen Quantifizierung Der Naturwissenschaftlichen Fakultät der Friedrich%Alexander%Universität Erlangen%Nürnberg zur Erlangung des Doktorgrades Dr.rer.nat. vorgelegt von Daniel Jansen aus Bamberg Dissertation Daniel Jansen, University Erlangen%Nünrberg, 2011 Als Dissertation genehmigt von der Naturwissenschaftlichen Fakultät der Friedrich%Alexander%Universität Erlangen%Nürnberg Tag der mündlichen Prüfung: 18.11.2011 Vorsitzender der Promotionskommission: Prof. Dr. Rainer Fink Erstberichterstatter: Prof. Dr. Friedlinde Götz%Neunhoeffer Zweitberichterstatter: Prof. Dr. Jürgen Neubauer % 2 % Dissertation Daniel Jansen, University Erlangen%Nünrberg, 2011 List of abbreviations ......................................................................................................................... - 4 - Abstract .............................................................................................................................................. - 6 - Zusammenfassung .........................................................
Publié le : samedi 1 janvier 2011
Lecture(s) : 51
Source : D-NB.INFO/1018308970/34
Nombre de pages : 144
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The hydration of an Ordinary Portland Cement (OPC) and the influence of selected
polymers: A mineralogical study using an external standard method for quantitative X-
ray diffraction

Die Hydratation eines Portlandzementes und der Einfluss ausgewählter Polymere:
Mineralogische Charakterisierung mittels einer externen Standard Methode zur
röntgenographischen Quantifizierung




Der Naturwissenschaftlichen Fakultät der
Friedrich%Alexander%Universität Erlangen%Nürnberg
zur
Erlangung des Doktorgrades Dr.rer.nat.

vorgelegt von

Daniel Jansen
aus Bamberg




Dissertation Daniel Jansen, University Erlangen%Nünrberg, 2011






Als Dissertation genehmigt von der Naturwissenschaftlichen Fakultät der Friedrich%
Alexander%Universität Erlangen%Nürnberg








Tag der mündlichen Prüfung: 18.11.2011
Vorsitzender der
Promotionskommission: Prof. Dr. Rainer Fink
Erstberichterstatter: Prof. Dr. Friedlinde Götz%Neunhoeffer
Zweitberichterstatter: Prof. Dr. Jürgen Neubauer



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Dissertation Daniel Jansen, University Erlangen%Nünrberg, 2011
List of abbreviations ......................................................................................................................... - 4 -
Abstract .............................................................................................................................................. - 6 -
Zusammenfassung ............................................................................................................................ - 7 -
1. Introduction ............................................................................................................................... - 8 -
2. Aim of the Research Work ..................................................................................................... - 10 -
3. State of Knowledge ................................................................................................................. - 14 -
3.1. Ordinary Portland Cement (OPC) CEMI 52.5 R ................................................................ % 14 %
3.2. Polymers ............................................................................................................................ % 16 %
3.3. Heat Flow Calorimetry ....................................................................................................... % 17 %
3.4. Powder Diffraction and the Rietveld%Method ................................................................... % 19 %
4. Results (Publications) ............................................................................................................ - 22 -
4.1. Does Ordinary Portland Cement contain amorphous phase? (Published in PDJ) ............ % 22 %
4.2. XRD Quantification of cement hydration using an external standard (Published in CCR) % 43 %
4.3. The hydration of alite (Published in JAC) .......................................................................... % 64 %
4.4. The early hydration of Ordinary Portland Cement (Published in CCR) ............................ % 81%
4.5. Influence of PDADMAC on the hydration of CEMI 52.5R( Submitted to CCC) ................. % 98 %
4.6. Influence of superplasticizers on the hydration of CEMI 52.5 R (Published in CCR) ..... % 117 %
5. Conclusion ............................................................................................................................ - 134 -
Acknowledgement ......................................................................................................................... - 144 -




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Dissertation Daniel Jansen, University Erlangen%Nünrberg, 2011
LIST OF ABBREVIATIONS

XRD X%ray Diffraction
wt.%% weight percent
OPC Ordinary Portland Cement
w/c%ratio water/cement%ratio

Cement minerals and hydration products of OPCs

Alite C S Ca (SiO ) 3 3 5
Belite C S Ca (SiO ) 2 2 4
Aluminate C A Ca Al O 3 3 2 6
Brownmillerite C AF Ca Al Fe O 4 4 2 2 10
Gypsum CsH CaSO *2H O 2 4 2
Bassanite CsH CaSO *1/2H O 0.5 4 2
Anhydrite Cs CaSO 4
Quartz S SiO 2
Calcite Cc CaCO 3
Arcanit e Ks K SO 2 4
Ettringite C A 3Cs H Ca Al (SO ) (OH) I26H O 3 32 6 2 4 3 12 2
Portlandite CH Ca(OH)2

Polymers

PDADMAC Polydiallyldimethylammonium chloride, cationic homopolymer of
% %
diallyldimethylammonium chloride, (Cl can be substituted by e.g. OH
2%,SO ) 4
SP Superplasticizer, in the present work polycarboxylate ether based
superplasticizers (PCE)

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Dissertation Daniel Jansen, University Erlangen%Nünrberg, 2011

Professional Journals

PDJ Powder Diffraction Journal
CCR Cement and Concrete Research
JAC Journal of Applied Crystallography
CCC Cement and Concrete Composites













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Dissertation Daniel Jansen, University Erlangen%Nünrberg, 2011
ABSTRACT

The influence on the hydration of a commercial Portland cement of two different
polymers used in dry%mix%mortar technology was examined by means of X%rdayiffr action. To
this end an external standard method was used and evaluated which turned out to be the
most elegant method available when working with cement pastes containing amorphous
phases. The external standard method was also used in order to examine the amorphous
content of the dry cement powder.
It was found that several structural parameters, such as atomic dislocation and
microstrain of the structure models, used for quantitative Rietveld analysismight lead to the
determination of false “amorphous” content. No actual amorphous content (phase with
missing crystalline structure) could be proven in the cement examined.
It turned out that the hydration process can be precisely examined using the
externalstandard method evaluated in this research. New insights into the hydration process
of a commercial OPC could be achieved. The heat resulting from the hardening of the
cement with water could be assigned to different reactions, namely the silicate reaction, the
dissolution of the aluminates, and the precipitation of ettringite.
The cationic polymer (PDADMA%X) which was used affects the hydration o fthe
cement as a function of the anionic counterion. The influence of the polymer is due to the
interaction of the polymer with the anions in the pore solution indirectly influencing the
cationic composition of the latter.
The polycarboxylate%based superplasticizer leads to a retardation of all reacionst
during cement hydration, without thereby showing a higher influence on any specific reaction.
Both the silicate reaction and the aluminate reaction are retarded where the superplasticizer
is present. Thus it is very conceivable that an interaction may here occur between the
2+
superplasticizer and the Ca ions from the cement pore solution, though other mechanisms
are also conceivable.

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Dissertation Daniel Jansen, University Erlangen%Nünrberg, 2011
ZUSAMMENFASSUNG

Die Hydratation eines handelsüblichen Portlandzements wurde mittels Röntgen%
diffraktometrie und Wärmeflusskalorimetrie untersucht. Dabei wurde eine Methode mit einem
externen Standard angewandt und evaluiert, welche in abbindenden Zementen noch nie zum
Einsatz kam. Die Methode stellte sich als eine sehr elegante Methode für die Untersuchung
von Zementpasten heraus.
Außerdem wurde der amorphe Gehalt eines handelsüblichen Zements untersucht. Es stellte
sich heraus, dass der Zement keinen amorphen (nicht kristallinen) Bestandteil aufweist.
Vielmehr ist es möglich mit falschen Werten für die Auslenkungsparameter der einzelnen
Atome oder den Microstrain für den Standard bzw. aller Phasen der Probe einen „falschen“
amorphen Anteil zu errechnen.
Weiterhin wurde der Einfluss zweier Polymere, welche in Trockenmörteln neben dem
untersuchten Zement eingesetzt werden, auf das Abbindeverhalten des Zements untersucht.
Dabei zeigt sich, dass das kationische PDADMA%X einen deutlichen Einfluss au fdie
Hydratation hat und diese in Abhängigkeit des anionischen Gegenions zu dem kationischen
Polymer entweder beschleunigt oder verzögert. Dabei spielt offensichtlich ein
Anionenaustausch zwischen Polymer und Zementporenlösung eine entscheidende Rolle.
Das Fließmittel (Polycarboxylat%basierend) verzögert sowohl die Silikateraktion als auch die
Aluminatreaktion während des Abbindens des Zementes.Es ist am denkbarsten, dass das
2+
Polymer durch das Entziehen von Ca %Ionen aus der Zementporenlösung verzögernd auf
das Abbinden des Zementes wirkt.






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Dissertation Daniel Jansen, University Erlangen%Nünrberg, 2011
1. INTRODUCTION

Cementitious building materials have been playing a major role in human life for
thousands of years. Binders less reactive than cement, such as lime or gypsum, have an
even longer history.
th
The introduction of cement onto the market in the 19 century provided the possibility of
new applications and products with better properties and durability.
Today Ordinary Portland Cement (OPC) is an important product in our daily life and it is
an irreplaceable part of numerous other products. It is the basis of many products of the
building industrysuch as concrete and dry%mix%mortars. The worldwide producion t of Ordinary
Portland Cement amounts to almost 3 billion tons a year. The global production of dry%mix%
mortars has already exceeded the amount of 100 mio tons a year [1].
thThe first investigations into the hydration of cements date back to the early 20
century.However, there are still many unsolved problems concerning the hydration of
cements, especially in modified cementitious systems like dry%mi%x mortars. One of the main
issues of research is to clarify the kinetics behind the hydration of Portland cement, which
can be seen from heat flow curves and the influence of all kinds of additives on the hydration
behavior.
It is a well known fact that two reactions are assumed for the hydration of an OPC with
water. The phase alite (chemically impure C S) reacts with water, forming portlandite and C%3
S%H%phase (equation 1). The sulfate carriers of the cement (anhydrite, gypsu,m bassanite)
react with C A and water, forming ettringite (equation 2). 3

Equ.1 C S + 3.9 H → C SH + 1.3 CH (silicate reaction) 3 1.7 2.6
Equ.2 C A + 3 Cs + 32 H → C A*3Cs*H [ettringite] (aluminate reaction) 3 3 32

Dry%mix%mortar systems are very important products and today’s standar d when it
comes to efficient and resource%saving construction sites [1, 2]. So%alcled ready%to%use
mortars are applied more and more often and are tending to replace job%site%mixed omrtars
at construction sites. Since they need to fulfill very different requirements for different
products, dry mortars are complex mixtures of many components such as inorganic binders
(Ordinary Portland Cements, Calcium Aluminate Cements, Sulfates), organic binders
(redispersible polymer powders, polymer dispersions), additives and aggregates. The
systematic addition of additives and functional polymers gives rise to products with a varying
field of application possibilities. The modification of concrete and mortars with polymers, in
particular, has turned out to be very advantageous.
Research into dry%mix%mortar systems is a very broad field. The bes mt eans of
improving mechanical properties, such as strength and adhesion,remain live scientific issues
[e.g. 3, 4, 5] and form the aims set by many research programs. The study of the
microstructuredevelopment of mortar systems [e.g. 6, 7, 8] is also a very important issue.
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Dissertation Daniel Jansen, University Erlangen%Nünrberg, 2011
In addition, there also exists a need to understand and investigate the influence of
numerous organic additives and aggregates on the hydration behavior of the inorganic
binders in mortar systems (references in chapter 4.5 and 4.6).
From a mineralogical point of view, OPC (a very important inorganic binder in many
products) is a mixture of several crystalline phases. During hydration (the hardening of the
cement after adding water) several crystalline phases are dissolved and hydration products
crystallize from the pore solution. The fact that OPC is a crystalline product means that
mineralogical studies using X%ray diffractometry can be helpful in examining the raw material
cement, the hardened cement stone, and also the hydration process. The quantification of
the phase development during cement hydration is a very powerful tool for demonstrating
reactions during hydration. A problem, however, for the quantification of the hydration
process is the fact that neither the water added to the cement nor the C%S%phasH% e which is
formed during hydration can, at present, be quantified by means of X%rays. This problem can
be overcome by using standard methods which also allow the quantification of the
amorphous phases (water, C%S%H%phase) in the cement paste.



[1] F. Leopolder, The global drymix mortar industry, ZKG International, 4 (2010) 32%45
[2] C. Winter, J. Plank, The European Drymix Mortar Industry, ZKG International, 60 (2007)
62%69
[3] J. M. Geist, S. V. Amagna, B.B. Mellor, Improved Portland Cement Mortars with Polyvinyl
Acetate Emulsions, Industrial and Engineering Chemistry, 45 (1953) 759%767
[4] J. Schulze, Influence of water%cement ratio and cement content ont he properties of
polymer%modified mortars, Cement and Concrete Research, 29 (1999) 909%915
[5] J.%H. Kim, R. E. Robertson, A. E. Naaman, Structure and prpero ties of poly(vinyl alcohol)%
modified mortar and concrete, Cement and Concrete Research, 29 (1999) 407%415
[6] J. Rottstegge, M. Arnold, L. Herschke, G. Glasser, M. Wilhelm, H.W. Spiess, W.D.
Hergeth, Solid state NMR and LVSEM studies on the hardening of latex modified tile
mortars, Cement and Concrete Research, 35 (2005) 2233%2243
[7] S. Seifert, J. Neubauer, F. Goetz%Neunhoeffer, H. Motzet, Appliatc ion of two%dimensional
XRD for the characterization of the microstructure of self%level ng i compounds, Powder
Diffraction, 24 (2009) 107%111
[8] A. Jenni, L. Holzer, R. Zurbriggen, M. Herwegh, Influence of polymers on microstructure
and adhesive strength of cementitious tile adhesive mortars, Cement and Concrete
Research, 35 (2005) 35%50

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Dissertation Daniel Jansen, University Erlangen%Nünrberg, 2011
2. AIM OF THE RESEARCH WORK

The aim of the present work was to clarify, from a mineralogical point of view, the
processes occurring in the course of the hydration of a commercial Portland cement, using
X%ray diffractometry combined with heat flow calorimetry. On this basis, there can be
examined the influence of two selected polymeric additives which are used in dry%mix%
mortars on the hydration behavior of the cement. Within the scope of the present research
work the focus was on the first 22 hours of the hydration process.
For the above%mentioned reasons, an OPC which is very often used in German dry%xm %i
mortar technology was chosen for the research performed.
The hydration of OPCs can be examined very well by means of X%ray diffracion t analysis.
Studies of this sort are nowadays helping us to understand many processes which occur
during the application of cement based products.
When working with X%rays the scientist has always to keep in mind thatonl y crystalline
phases with a known structure and sufficient peak intensities can be quantified. Although
possibilities exist for quantifying phases with partially%known or unknown cyrstal structures
[1], the mixing water introduced into the cement in order to start the hardening process
cannot be quantified by means of X%rays. Moreover, hydration products may also display
(especially during early hydration) an unsatisfying degree of crystallinity (e.g. C%S%H%phase).
These factors might lead to wrong quantitative values for the crystalline phases in a cement
paste (see chapter 4.2.).
The application of X%ray diffraction to hydrating cementitious systems was already
suggested by scientists several years ago. Neubauer et al. [2] suggested a conversion of the
data obtained from Rietveld analysis in order to get true quantitative results for the cement
paste. This method was carried on by Hesse [3]. Mitchell et al. [4] and Scrivener et al. [5],
however, suggested using an internal standard method for the quantitative analysis of
cement pastes.
Generally speaking, one of the most important aims of the scientists who work with X%ray
diffraction and hydrating cementitious systems is to find the most suitable standard method in
order to quantify the crystalline phases in a cement paste. A standard method suitable for
obtaining absolute quantities for each crystalline phase in a mixture of crystalline (clinker
phases, hydrate phases) and amorphous phases (e.g. water, C%S%H%phase) is ther ree fomost
appreciated.






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