’Agostino - International Cement Microscopt...

Binders by Alternative Cementitious Materials

F. Goetz-Neunhoeffer, S. Klaus & J.

Neubauer

Hydration of a ternary binder model system and the influence of citric acid on phase evolution

L. Gobbo & L. M. Sant’Agostino Industrial white cement properties suitable to raw material variation

S. Stöber, G. Redhammer, S. Schorr & H. Pöllmann

Modular Mn - perovskite type structures of modified calcium aluminate cements

C. O. Mangassy, G. Beuchle & P. Stemmermann

Development of a Microstructural Investigation Routine on Hydraulic Binders

A. Lo Presti, T. Cerulli, M. Dragoni, A.

Biancardi, E. Moretti, D. Salvioni

Interaction of polycarboxylate-based superplasticizers with cements : an introduction

F. Curto, T. Cerulli, S. Carrà, A. Lo Presti, M. Dragoni, D. Salvioni

Interaction of polycarboxylate-based superplasticizers with cements : a rheological point of view

M. Ecker A new highly precise temperature control in the range of 0 – 80 °C for XRD sample holders

H. Pöllmann, R. Maier & D. Götz X-ray Tomography of cementitious samples and natural stones using laboratory X-ray powder diffractometer

H. Al Nageim & M. A. Abbas Stiffness and deformation properties of a composite asphalt concrete surface pavement layer containing cement coated aggregates

A.I. Korobkova, O.A. Shilova & O.V. Frank-Kamenetskaya

Microstructure and mineralogical composition of portland cement materials with nanodiamond additives

T. Howind, J. J. Hughes & W. Zhu Correlation of Ca/Si and micromechanical properties in leached grey and white cement pastes.

D. H. Campbell Clinker and cement - microscopical quality control with Ono’s method

M. Boehm Effects of AFR on clinker properties

K. Peterson Regressions in portland cement clinker microscopy – clinker from 1906: a snapshot of the early american portland cement and road construction industries

F. Sorrentino Effects of the simultaneous presence of minor and trace elements on the mineralogy of Portland cement clinker

J. Soedje Effect of alternative fuel combustion on refractories in cement rotary kilns

T. Staněk & P. Sulovský The combined influence of minor oxides on the portland clinker properties

S. Ibrahimi, N. B. Jamaa, M. Bagane Influence of raw material’s parameters on the clinker’s grindability and cement quality

T. Westphal & T. A. Bier Phase and structure development in rapid

setting mortars

Table of contents

P. Stemmermann Reducing the CO2Footprint of Inorganic

J. Neubauer & F. Neunhoeffer New Findings on Early OPC Hydration using G-Factor Rietveld Refinement of XRD Data

T. Witzke Quantification of cements by rietveld-full pattern methods

M. Fylak & H. Pöllmann Application of Cryo Scanning Electron Microscopy for the Investigation of Early OPC-Hydration

T. Ramlochan & R. D. Hooton Use of X-ray Diffraction to Investigate the Early Stiffening of Cement Pastes

B. E. Möser Nanoscale Building Material Characterization by means of High-Resolution SEM Imaging Techniques

B. Raab & H. Pöllmann Synthesis and characterization of nanoscale hydraulic high reactive phases of Portland cements and calcium aluminate cements

A. Rodrigue, B. Fournier & J. Duchesne Microscopic analysis of secondary reaction products in concrete incorporating sulphide-bearing aggregates

S. Al-Busaltan & H.Alnageim Use of SEM and XRD for characterisation of the engineering properties of a new CMEM’s containing cementitious fillers

M. Dragoni, A. Lo Presti, T. Cerulli, A. Biancardi, E. Moretti & D. Salvioni

Interaction of polycarboxylate-based superplasticizers with cements: synthetic calcium carbonate as a model to investigate the structural evolution of C-S-H

T. Sibbick & C. LaFleur Determination of water to cementitious (w/cm) binder ratios by the use of the fluorescent microscopy technique in hardened concrete samples: Part II

H. A. Heinemann & O. Copuroglu Historic lime-binders: an example of 19th century Dutch plain concrete

M. Sadique & H. Al-Nageim Identification of Mineralogical Changes towards Advanced Reactivity of Fly Ashes for Mechanical Activation

F. H. Shrimer & A. Bromley Pyritic heave in Ireland: the role of petrography

V. Bams Study of pop-outs in concrete caused by secondary aggregates

M. Dragoni, A. Lo Presti, T. Cerulli, A. Biancardi, E. Moretti & D. Salvioni

Interaction of polycarboxylate-based superplasticizers with cements: effect of the polymer on structural rearrangement of the C-S-H gel during the hydration of portland cement

P. Laugesen An on-line in-situ ASR investigation of the pylons of an 80 years old concrete bridge

F. Cella, C. Maltese, C. Pistolesi, D. Salvioni, A. Bravo, T. Cerulli & E. Moretti

Analytical and technological study of a grout used for water tighting of dam upstream face

M. Schmidt, H. Poellmann & A. Egersdoerfer

The use of a recycled glass powder and a foam glass containing metakaolin in different binder systems

T. A. Bier Pore structure of hardened mortars based on different cementitious materials

J. Meinhardt & M. Zötzl Analyses in monument preservation - Characterisation of historical mortars and concrete by microscopy

T. Dealy Photomicrographs of Common Oilfield Cementing Additives

Reducing the CO2Footprint of InorganicBinders by Alternative CementitiousMaterials

Peter Stemmermann (Karlsruhe Institute of Technology-Germany)

Abstract

The global demand for cement-based building materials in general and concrete in particular has strongly increased in the last decades. The corresponding CO2 emissions face the cement manufacturers with difficult ecological challenges and economic ones are also likely to come. In addition to the use of energy, it is the calcination of lime which is critical in the clinker burning process. In the last decade therefore, there have been great efforts to strongly increase the use of secondary raw materials such as fly ash and blast furnace slag to replace Portland cement clinker. However, especially with respect to blast furnace slag this approach is limited due to the quantities available and its disputable CO2 footprint.

New sustainable solutions must keep up with an extremely competitive product. In particular, resources to produce alternative bindersmust be worldwideavailable, manufacturing must be possible at a competitive price and with globally deployable technology. Its application should be as simple and universal as OPC. At present a variety of approaches is being developed worldwide, which differ more or less from conventional systems. Very close to conventional binders is e.g. the production of latent hydraulic substitutes from natural raw materials. Other approaches, such as the use of magnesium silicate-based systems and geopolymers are also improved.

At the Karlsruhe Institute of Technology (KIT) the Celitement process has been developed that, like traditional cements,is based on the formation of calcium silicate hydrates upon hardening. Celitement is made from conventional raw materials, but in a completely new two-stage process. The first step comprises the synthesis of calcium silicate hydrates in an autoclave as used in the aerated concrete industry. In the second step, the products from the autoclave are mechanically activated. In this way half of energy and CO2-emissions associated with conventional clinker production can be saved. As of today, there will be more than one successful solution, depending on the particular location and the locally prevailing requirements in construction.

Keywords: Sustainable cement, CO2, embedded energy, alternative cements

Literature:

Garbev, K.; Beuchle, G.; Schweike, U.; Stemmermann, P. (2011): Hydration Behavior of Celitement®: Kinetics, Phase Composition, Microstructure and Mechanical Properties. ICCC 2011.Madrid, 06.07.2011.

Stemmermann, P.; Beuchle, G.; Garbev, K.; Schweike, U. (2011): Celitement® – A new sustainable hydraulic binder based on calcium hydrosilicates. ICCC 2011.Madrid, 06.07.2011.

Stemmermann, Peter; Schweike, Uwe; Garbev, K.; Beuchle, G.; Möller, H. (2010): Celitement - a sustainable prospect for the cement industry. In: Cement International 8 (5), S. 52–66.

Corresponding author: [email protected]

Hydration of a ternary binder model system and the influence of citric acid on phase evolution

Friedlinde Goetz-Neunhoeffer, Sebastian Klaus, Juergen Neubauer

Friedlinde Goetz-Neunhoeffer, University Erlangen-Nuernberg, GeoZentrum Nordbayern,

Lehrstuhl für Mineralogie, Schlossgarten 5a, 91056 Erlangen Email: [email protected]

Mixes were prepared from synthesized calcium aluminates CA and C3A, which represent calcium aluminate cement and silicate-free OPC together with calcium sulfates. The mixes were investigated with respect to the question of the influence of citric acid on hydration and ettringite formation. For better comparison of the technical with the model system an inert filler was added to be able to use similar w/s ratios and citric acid concentrations as for technical applications. The interesting calcium sulfates, bassanite und anhydrite II, were synthesized from gypsum by temperature dehydration processes. The temperatures were chosen according to Seufert et al. (2009). Reagent grade gypsum was dehydrated at 85 °C for 144 h in order to get pure bassanite und at 550 °C for 16 h in order to obtain pure anhydrite II. The cement phases CA and C3A were synthesized from CaCO3 and α-Al2O3 at 1400°C and ground to an appropriate specific surface area (Blaine 3800 resp. 4700 cm2/g). The calcium sulfates were investigated by XRD at 7 % rel. humidity, CA and C3A under atmospheric conditions. The obtained data were refined by Rietveld analysis. From the starting single phases model mixtures were produced which represent an OPC/CAC ratio of 9:1 with respect to the aluminates content. The ternary binder mixes were investigated by heat flow calorimetry and for their quantitative phase evolution during the first 24 h of hydration with deionized H2O with and without citric acid. During hydration of the mixes ettringite and minor amounts of monosulfate 14-hydrate are forming. A low amount of 0.1 wt% citric acid in the mixing water leads to more precipitated ettringite during the first 15 min. After the initial hydration of the ternary binder model mix more C3A is found to be dissolved. But then the dissolution of C3A is not proceeding up to 2 h of hydration and then continues again up to 3 h. The dissolution of CA is only little affected when citric acid is dissolved in the mixing water. Bassanite cannot be detected in the pastes after mixing nor with H2O neither in the citric acid containing solution. Kinetics of ettringite formation is strongly influenced by the presence of citric acid in contrast to its formation in pure H2O. After 3 h the maximum ettringite content is reached with citric acid. In comparison the maximum ettringite for pure H2O solution was already reached after 1.5 h. This shows that citric acid is acting as an accelerator during the initial hydration and as a retarder between 15 min and 3 h. S. Seufert, C. Hesse, F. Goetz-Neunhoeffer, J. Neubauer, Quantitative determination of anhydrite III from dehydrated gypsum by XRD. Cement and Concrete Research, Vol. 39 (2009), 936-941.

INDUSTRIAL WHITE CEMENT PROPERTIES SUITABLE TO RAW MATERIAL VARIATION

Gobbo,L.A. (e-mail: [email protected])

Sant’Agostino, L.M. (e-mail: [email protected])

White Portland clinker is composed of three basic oxides (CaO, Al2O3 and SiO2) and minor components such as Na2O, K2O, SO3, etc, crystallized as alite (C3S) and belite (C2S) and surrounded by C3A, in cubic or orthorhombic (when enriched in alkalies)crystaline systems. Orthorhombic C3A lead to variations in the initial and final settings of the cement. The aim of this research is to show the differences among the clinkers and cements produced with two different raw materials, one with tonalite rock as Al2O3 and SiO2 source and other with quartzite rock, enriched in Al2O3. Microscopy showed morphological differences between samples of the two groups. Microanalysis allowed the correlation of alkali grade with the C3A polymorphs. The XRD-Rietveld method was an important and precise tool on quantification, allowing the quantification of different aluminate types. Cement properties as strengths and settings were also analysed and compared showing different performances for the samples.

MODULAR Mn - PEROVSKITE TYPE STRUCTURES OF MODIFIED CAL-

CIUM ALUMINATE CEMENTS

Stefan Stöber1, Günther Redhammer2, Susan Schorr3,, Herbert

Pöllmann1

1Martin - Luther - Universität Halle Institut für Geowissenschaften Mineralogie/Geochemie Von Secken-

dorff - Platz 3 06120 Halle (Saale) 2Universität Salzburg FB Materialforschung und Physik Abt. Mineralogie Hellbrunnerstrasse 34 A - 5020

Salzburg 3Freie Universität Berlin FB Geowissenschaften Mineralogie/Petrologie Malteserstrasse 74 - 100, Haus N

12249 Berlin Abstract

During the melting process of Mn - modified Calcium Aluminate Cement crystallize Calcium Alu-

minate and different perovskite phases with the chemical composition Ca2(Al,Fe,Mn)2O5+d and

Ca(Fe,Mn,Ti)O3-d [3], [4]. Due to the variable oxygen fugacity of the gas phase during the cooling process

Manganese can adopt different oxidation levels which influences the perovskite structure. Brownmillerite

type phases with a tetrahedron (t) - octahedron (o) sequence t-o can change to a t-o-o or o-o sequences

which are common in so called “oxygen frustrated perovskites”[2] and in ternary perovskites. The forma-

tion of those phases must be seen as a result of the generation and ordering process of oxygen voids in the

perovskite - type structure [1]. In order to investigate these phases, different samples of solid solution se-

ries in the system CaO-Fe2O3-Mn2O3-TiO2 were synthesized. For those purposes, the phases were synthe-

sized applying oxides and in a further step applying sol-gel methods. The mean oxygen content was inves-

tigated by iodometric titrations and the iron valence state was investigated using Mössbauer - spectroscopy.

Neutron diffraction experiments were performed at the BENSC instrument E6 Helmholtz-Centre Berlin

for Materials and Energy, in order to refine the crystal structures.

Development of a Microstructural Investigation Routine on Hydraulic Binders

Chérif O. Mangassy, Günter Beuchle and Peter Stemmermann (Karlsruhe Institute of Technology-Germany)

Abstract

The microstructural investigation on hydraulic binders is a complicated and problem-specific topic, especially interesting for e.g. pore structure evolution and binding of aggregates. Many authors have tried to describe the internal structure of Portland cement with different and presumably suitable methods. Further on, the processes occurring during the hydration of Portland cement were interpreted. Unfortunately, not only methods for preparation and analytics but also the interpretations differ from each other. Microstructural investigations mostly require microscopic imaging. However, these alone are not sufficient for expressive interpretations. Other tools are necessary to determine chemical composition, porosity and for identifying the hydrates: i.e. X-ray diffractometry, spectroscopic analytics and mercury-intrusion porosity. The different analytical approaches are often applied on differently prepared samples and require quite often pre-treatment, which can lead to artefacts and disturbances.

That is why we have developed a type of preparation, which allows for application of all necessary analytics on one sample, usually with a disc-like geometry.

After gauging, the cement mixture is poured in to a circular metal mould then covered with a plastic lid and stored in an exsiccator at 100% relative humidity up to the desired time of hydration. At that time, samples are unmoulded. X-ray diffractometry is performed on the underside of the disc. Fracturing of the disc generates a fresh surface and gives access to the inside of the sample for imaging. Since mercury intrusion porosity is applied on powders, the hydration disc is ground and then examined. Because of the planarity of the underside, it can be used for spectroscopic methods like Raman and Infrared spectroscopy and mapping, too.

We present results of investigations on hydration discs, e.g. of ordinary Portland cement CEM I 32,5R, prepared by the described method. The samples were all mixed with a water/cement ratio of 0.3. To reduce the amount of air voids we added 1 wt.% of superplasticizer. The measurements were made after 1d, 7d, and 28d hydration. The methods used were X-ray diffractometry, mercury porosity and scanning electron microscopy. We also employed cryogenic microscopy for imaging of the microstructures in order to reduce contamination; fresh surfaces can be obtained as well by cutting. X-ray diffractometry was used for the identification of the occurring minerals. Information about the pore size distribution was obtained by mercury intrusion porosity.

Data could be retrieved from the same sample with the three used methods and thereby getting meaningfully results. The pore size distribution of the mercury intrusion porosity could be reconstructed on the SEM images. The minerals were assigned with the help of the X-ray analysis. Due to the good correlation of the results, a description of the processes involved in the hydration of ordinary Portland cement was possible.

This preparation method is easy, free of chemicals for preparation and applicable for a range of analytical methods. It merely assumes that the samples harden. It is suitable for the investigation of hydration times of 12 hours and above.

Keywords: preparation, cement, hydration, microstructure, cryo-microscopy.

Literatures

Locher, F. W.: Zement: Grundlagen der Herstellungund Verwendung. Verlag Bau+Technik, Düsseldorf (2000). Taylor, H.F.W.: Cement Chemistry. Academic Press, London 1997. Jürgen Göske; Susanne Winter; Herbert Pöllmann; Richard Wenda (2009): Hydraulische Reaktionen des Zements in Mörtel bei verschiedenen Parametern Analytische Betrachtungen mittels Kryotransfer-Rasterelektronenmikroskopie. 17 ibausil, Weimar (2009). Corresponding author: [email protected]

Phase and structure development in rapid setting mortars

Torsten WESTPHAL1, Thomas A. BIER1

1 Institut für Keramik, Glas- und Baustofftechnik, TU Bergakademie Freiberg, Leipziger Straße 28, D- 09596 Freiberg,

Germany, [email protected], phone +49-3731-39-3132 Fax +49-3731-39-2223

Abstract

Rapid setting grouting mortars are used e.g. for anchoring machines or manhole frames. Besides

rapid setting and excellent flow properties, high early strength and volume stability is desired. To

achieve these properties, such mortars are a complex mixture of active components. Usually they

consist of a mixture of Portland Cement (OPC), Calcium Aluminate Cement (CAC) and a sulphate

carrier as binder with a super plasticiser, accelerator, retarder, and stabiliser fine tuning setting and

workability. Also fine fillers such as limestone powder can contribute to technical properties and

phase and microstructure development.

Commercially, such mortars are niche products. Therefore, there is only some knowledge publically

available about formulations and technical properties. But systematic knowledge about the

influence of the active components on the hydration process is largely missing. Studies were carried

out to better understand and to improve these mortars. Model formulations with systematically

varied composition have been used to study phase and structure development during the first 24

hours. The dynamics of phase and structure development of these model mixtures were described

and compared.

INTERACTION OF POLYCARBOXYLATE-BASED SUPERPLASTICIZERS WITHCEMENTS : AN INTRODUCTION

A. Lo Presti, T. Cerulli, M. Dragoni, A. Biancardi, E. Moretti, D. Salvioni

Mapei S.p.A. R & D Central Laboratory, Milan , Italy

ABSTRACT

An understanding of the mechanical performance of Portland cement-based materials requires

knowledge of the microstructural modifications that occur during the early stages of the hydration

process. When water is added to the cement powder, the reactions which occur are mostly

exothermic. We can get an indication of the rate at which the different phases are reacting by

monitoring the heat evolution and thus observing the time-temperature curve.

It is interesting to observe how the curve profile changes when adding a polycarboxylate-based

superplasticizers: the first peak, usually attributed to the formation of an aluminate-rich gel and to

the formation of small needles of ettringite does not change its position but can vary its intensity,

while the following period of a few hours of relatively low heat evolution, that corresponds to the

second peak, became longer. It is well known that the nucleation of crystalline products from an

amorphous layer depends on particular circumstances and admixtures may enter the gel modifying

its structure in terms of quality and quantity.

To better understand the reasons of this behaviour, some experiments have been carried on.

A Quantitative X-Ray Diffraction analysis (QXRD) showed that the consumption kinetics of the

phases is strongly affected by the superplasticizers and in the same way also the morphology of the

hydrates, as observed by electronic microscopy. In particular the C3S hydration seems to be the

more influenced by the presence of these admixtures.

INTERACTION OF POLYCARBOXYLATE-BASED SUPERPLASTICIZERS WITHCEMENTS : A RHEOLOGICAL POINT OF VIEW

F. Curto, T. Cerulli, S. Carrà, A. Lo Presti, M. Dragoni, D. Salvioni.


ABSTRACT

Rheological techniques are commonly aimed at test pumpability and workability of cement based

products. In this work they have been used in order to evaluate the viscosity and the cement

reactivity. The rheological study has been carried out following a measurement protocol that

provides an oscillatory and continuous procedure to characterize reactivity and flowability when

admixtures are added.

Different behaviours have been observed; to investigate the reasons of this phenomenon others

techniques have been combined such as a Quantitative X-Ray Diffraction analysis (QXRD) and

morphological observations made by electronic microscopy (ESEM).

Microscopy showed how a superplasticizer can affect the habit of the hydration products. Besides, a

correlation between rheological and diffractometric results has also been found

A new highly precise temperature control in the range of 0 – 80 °C for XRD sample holders

Michael Ecker, MESICON The ambient temperature has a strong influence on the kinetics and phase formation during the hydration of hydraulic binders [1]. Therefore for the description of hydraulic reactions, the strict observance of exact temperatures is necessary. Climate cameras for many XRD applications and with a wide temperature range are available since many years. But there was no tool especially suited for the demands of the hydration reaction investigations in cement chemistry. For this reason a compact sample holder with a temperature range of 0 – 80 °C was developed. To enable tempering direct at the sample, heating and cooling is done by a peltier element. The sample holder with about 80 mm in diameter and a height of 30 mm has only a weight of 150 g and is inserted in the XRD device like a normal sample holder. The sample is prepared in a so called sample carrier of PMMA. This sample carrier is placed in the stainless steel sample holder which is tempered by the peltier element. During cooling the sample, the hot site of the peltier element is cooled by a water cooling system. The temperature of the sample holder is measured by a temperature sensor Pt 100. Additionally the temperature of the cooler and the ambient temperature are measured. Temperature control is not done by a commercial controller, but by computer interfaces and software. With this system it is possible to adapt the controlling algorithm exactly to the conditions of tempering by a peltier element. Inaccuracies have been minimized by using Pt 100 temperature sensors with an accuracy of 0.1 or 0.03 °C. The resolution of the temperature interface is 16 bit (0.003 °C). The controller allows controlling of the temperature with a deviation of ± 0.02 °C from the target temperature. Main sources of error are the temperature transition between the steel of the sample holder and the PMMA of the sample carrier and the temperature gradient within the sample. This deviation can be corrected by measuring the temperature within the sample at different temperatures and ambient conditions and make an automatic correction by the controller software. Another difficult point is to reach and to hold temperatures exactly, which are very close to room temperature. For this case a technical solution was developed. Literature: [1] Hesse, C.; Degenkolb, M.; Gäberlein, P.; Götz-Neunhoeffer, F.; Neubauer, J.; Schwarz, V.: Investigations into the influence of temperature and w/c ratio on the early hydration of white cement. Cement International 6 (2008), pp 68-78

Abstract for ICMA meeting in Halle/Saale

X-ray Tomography of cementitious samples and natural stones using laboratory X-ray powder diffractometer

Herbert Pöllmann, Roger Maier*, Detlev Götz*

University of Halle/Saale

*Panalytical/Almelo

A laboratory X-ray diffractometer system was used to characterize different cementitious samples and some natural rocks for phase analysis and x-ray tomography.

The X-ray experiments were accompanied by different other methods like SEM, microscopy and chemical methods. A typical X-ray tomographic sample is shown in figure 1.

Fig.1: Vizualization of voids in mortar sample

1

Stiffness and deformation properties of a composite asphalt concrete surface pavement layer containing cement coated aggregates

Professor Al Nageim H1, Dr. Abbas M. A2

1. Professor of Structural Engineering, Head of Liverpool Centre for Materials Technology

School of the Built Environment, Liverpool John Moores, LJMU, Byrom Street, Liverpool L3 3AF, UK

2. LJMU Graduate 2010

ABSTRACT This paper reports the finding of an extensive study on the design and characterization of

asphalt concrete composite surface layer made from Open Graded Friction Course asphalt

mixtures (OGFC) containing modified secondary aggregates, with cement paste, for use as

road pavement material. Three aggregate types were considered in this study; Arcow (as a

control), Croxden aggregates (as a secondary material) and cement coated Croxden

aggregates (as a material under investigation). One aggregate gradation was designed for

all aggregate types and the adopted aggregate gradation had a nominal maximum aggregate

size of 14mm. The binder used was a 100/150 pen binder. The primary objective of this

research study was to investigate the mechanical and deformation properties of pavement

layer made from cement coated secondary aggregates under different loading and traffic

environmental conditions. Stiffness and deformation properties of the control and new

composite pavement layer were measured using triaxial and wheel track at testing

temperature of 200C, 300C and 450C. The results confirmed that the new composite

pavement layer is suitable for use in road surfacing materials and thus significant

economical and environmental benefits can be achieved.

Keywords: Stiffness modulus, Secondary aggregates, composite materials, Deformation,

Wheel tracking.

MICROSTRUCTURE AND MINERALOGICAL COMPOSITION OF PORTLAND CEMENT MATERIALS WITH NANODIAMOND ADDITIVES

A.I. Korobkova*1,2, O.A. Shilova1, O.V. Frank-Kamenetskaya2 1 ICS RAS, 199034, St.Petersburg, Russia

2 SPb State University, 199034, St.Petersburg, Russia *e-mail: [email protected]

The specificity of carbon nanoparticles structure and properties causes more and more growing interest in applying them as additives in various materials. It is known adding carbon nanoparticles (as a sol, fullerenes, nanotubes, nanodiamonds and schungites) to cement material increase their strength. However physico-chemical mechanism of this effect is investigated not enough.

In the paper the results of researching synthesized hydrous Portland cement materials doped detonation

nanodiamond (DND) by methods of powder X-Ray Diffraction and light and scanning electron microscopy are

presented. The main aim was to research phase composition and microstructure of new Portland cement materials and

find out a relation with their strength.

There were two series of materials based on the clinker from Suhologsky work syntheses doped DND (0; 0,1;

0,2; 0,5; 1 – 9 wt. %), that were distinguished by the absence (1st series) or presence (2nd series) of gypsum

CaSO4*2H2O addition in the amount of 5 wt. %. Phase composition was determined by X-Ray method (STOE

STADI P powder diffractometer, transmission geometry, Cukα1=1,54056, 2θ=5-55°, ∆2θ=0,02°, exposition 100 sec.)

Besides, to identify features of DND particles distribution in hydrated samples scanning electron microscopy (Quanta

200 3D) was used. SEM research was carried out in reflected electrons (high vacuum, U=15-20kV, analyst S.J.

Yanson).

The phase composition in samples of the 1st series is alite Ca3SiO5, belite Ca2SiO4, calcium aluminate

Ca3Al 2O6, brownmillerite Ca4(Al,Fe)4O10: there are four major phases of Portland cement clinker, portlandite

Ca(OH)2 – product of alite and belite hydration and also calcite plus aragonite CaCO3. In speciments of 2nd series it is

the same, but also ettringite Ca6Al 2(SO4)3(OH)12*26H2O – the product of calcium aluminate and gypsum hydration is

absent. The amount of portlandite and calcium carbonates in different samples is not the same. In 1st series their

maximum content is achieved in samples with 0.1 – 0.5 wt. % DND and another maximum of portlandite is at 4 - 5

wt. % DND. In 2nd series there is a gradual increase of these minerals up to 9 wt. % DND. There are no peaks of

another hydration product – calcium hydrosilicate on the X-Ray picture because of this X-Ray amorphous. But there

is dark fringe of calcium hydrosilicates around the grains of cinker’s phases at SEM images. Besides we can see, that

portlandite is coincided with the nanodiamonds aggregations.

Maximum compressive strength in 1st series is in samples with 0.1 – 0.5 and 4 - 5 wt. % DNA, at higher

contents of DND material becomes brittle and disintegrates. Maximum strength in 2nd series is observed at 0.1 wt. %

DND. The destruction of the material in investigative range isn’t observed.

On the one hand, portlandite alters the rate of material hydration, on the other hand, takes part in reaction with

DND, which’s a large concentrations can be course of incomplete hydration of another clinkers phases and low

strength. The investigation of physico-chemical mechanisms is in progress now.

Nevertheless, the results had shown the addition of nanodiamond affected on the phase composition and

strength characteristics of Portland cement materials significantly. Such materials can be used in strategically

important facilities constructing, which is need to have a high strength. Relatively small concentrations of DND,

which have most effect on cement’s properties cause low price of new materials and economic benefits of their

production.

Correlation of Ca/Si and micromechanical properties in leached grey and white cement

pastes.

Howind, T., *Hughes, J. J. and Zhu, W.

School of Engineering, University of the West of Scotland, Paisley Campus, PA1 2BE

*corresponding author, [email protected] , +44 141 848 3268

Grey and white Portland cement pastes were prepared and hydrated for 28 days and then

partially Ca leached in ammonium nitrate. The samples were then subjected to

micromechanical and compositional analysis. Polished surfaces were interrogated using

nanoindentation for Young’s Modulus and Hardness. Indents and hydration structures were

then imaged by FESEM, and EDS applied for elemental analysis across a traverse from the

exterior to interior of the samples to ascertain the degree of change to Ca/Si in non-

degraded and degraded portions of samples. A good agreement is seen between Ca/Si and

mechanical properties. The microstructure of the degraded parts shows evidence of

increased porosity and alteration to unhydrated binder components. Adequate sample

preparation was a critical factor for nanoindentation, to ensure high flatness of the sample

surface prior to testing. This results also in an improvement in SEM imaging, and phase

discrimination.

CLINKER AND CEMENT-- MICROSCOPICAL QUALITY CONTROL WITH ONO’S METHOD

Donald H. Campbell*

Campbell Petrographic Services DBA Campbell Petrographics Dodgeville, Wisconsin USA

ABSTRACT After a partial review of Ono’s contribution to our industry, emphasis in this paper is given to the use of the microscope, studying grain mounts and polished sections in reflected and transmitted light, sometimes called “Ono's Method.” The Ono Method emphasizes interpretation of kiln conditions, specifically, the heating rate, maximum temperature, time at high temperature, and cooling rate. A revised set of microscopical parameters for these interpretations of kiln conditions, based largely on Ono’s microscopical work and that of the author, is offered. To this is added certain characteristics of raw meal, namely, Q45, C125, Q125, and R45. Improved methods of sample preparation, ranging from polished clinker nodules to powders, use of KOH-sugar solution residues, sieving with polyester cloth, and time-saving methods of particle counting are described. Other microscopical data that help to explain cement performance are: silicate crystal sizes, percentages of tightly packed belite nest fragments, alite-to-belite ratios, C3A abundance and crystal size, added sulfate mineralogies and their percentages, free lime abundance, and many other items. Properly performed, according to Ono, the method provides a valuable prediction of 28-day mortar strength with a correlation coefficient of approximately 0.91, with a standard deviation of roughly 17.1 kg/cm2. This paper is based on the writer's Chapter 9.3 of the Portland Cement Association's “Innovations in Portland Cement Manufacturing” (2011).

Abstract for the 34th ICMA Conference, Halle, Germany

EFFECTS OF AFR ON CLINKER PROPERTIES By: Matthias Boehm VDZ Duesseldorf, Germany

Significant amounts of alternative fuels and raw materials (AFR) are used today in the production process of Portland cement clinker. These materials not only can lead to economic benefits, but also lower the consumption of natural resources and the emission of carbon dioxide due to the combustion of fossil fuels and the calcination of limestone. However, AFR can lead to changes in the clinker mineralogy and microstructure. The incorporation of raw material and fuel ash particles in the clinker granules and their contribution to the clinker phase formation is dependant on the granularity of the particles, their distribution in the kiln feed and their chemical composition. The analysis of different clinker samples (technical and laboratory clinker) with optical microscopy showed how the local enrichment of different oxides can change the clinker microstructure. Due to their combustion properties some alternative fuels can locally lead to reducing burning conditions in the clinker bed, which can cause changes in the phase composition of clinker. The reliable identification of such local reducing conditions in the kiln is only achievable with clinker microscopy. An example shows that even the identification of the specific material causing the reducing conditions is possible. Therefore clinker microscopy is a powerful tool to reveal the influences of AFR on the clinker microstructure and to rectify possible quality losses.


REGRESSIONS IN PORTLAND CEMENT CLINKER MICROSCOPY –CLINKER FROM 1906: A SNAPSHOT OF THE EARLY AMERICAN PORTLAND CEMENT AND ROAD CONSTRUCTION INDUSTRIES By: Karl Peterson University of Toronto Toronto, Ontario, Canada For some people, staring down a microscope at reflections from clinker (or at light passing through clinker) is like staring into the fiery depths of the rotary kiln itself. From Le Chatelier to the microscopists of today, the development of the art and science of cement microscopy has been rich and varied. Don Campbell, for whom this symposium is organized, has contributed everything from lectures to literature, from hands-on demonstrations to technical innovations, from micrographs to monographs. From him the community of cement producers, users, and researchers have learned so much. To celebrate, this paper describes the examination of a core from a hundred-year-old concrete pavement, and efforts to determine the provenance of the cement used in this historic roadway.

Effects of the simultaneous presence of minor and trace elements on the mineralogy of Portland cement clinker

François Sorrentino

www: mineralresearchprocessing.fr Meyzieu, France

The present study is a part of a wide project aiming at understanding the influence of minor and trace elements on the mineralogy of Portland cement clinker. Many papers have dealt with the minor elements that are independently present in cement clinker and the individual effects of these elements on the clinker formation. Despite the extensive literature on the subject, available data are incomplete (particularly Cu, Ni, Sn or Zn). On the other hand, we find only a few records on the evaluation of the simultaneous impact of these minor elements. In a first step, the maximum amount of these elements (Cu, Ni, Sn or Zn) that could be incorporated individualy into the major phases of a standard laboratory clinker has been measured and a threshold limit was determined. In a second step, Na, K, Mg, Mn, Ti, P, S, Zn, Zr, Sn, Pb, Bi, V, Cr, Cu and Ni have been added simultaneously to the same standard clinker and the quantity of elements dissolved as a solid solution was measured in each phases by SEM. In this paper we discuss the variation of the threshold limits of each of these trace elements due to simultaneous presence of the others elements in their environment.


EFFECT OF ALTERNATIVE FUEL COMBUSTION ON REFRACTORIES IN CEMENT ROTARY KILNS By: Dr. Johannes Soedje Refratechnik Cement GmbH Gottingen, Germany

The substitution of primary fuels by alternative fuels in the cement industry leads to changes in the process conditions. the alterations additionally have significant influences onto the refractory lining. The presentation shows examples of different wear phenomena which are connected with the use of alternative fuels.

THE COMBINED INFLUENCE OF MINOR OXIDES ON THE PORTLAND CLINKER PROPERTIES

Theodor Stan ěk 1, Petr Sulovský 2,

Abstract

The paper is aimed at the assessment of the influence of P2O5 combined with other minor oxides (SO3, MgO, K2O a Na2O) on the formation and phase composition of Portland cement clinker. The results were obtained using optical and electron microscopy, microprobe and X-ray diffraction. It was determined, that some oxides and their combinations partially eliminate the negative influence of P2O5 on the phase composition of clinker and especially on the formation of alite. It is stated, that the combination of P2O5 with certain minor oxides leads to cements with better technological properties than cements prepared from clinkers doped only with P2O5. The positive influence lies especially in acceleration of hydration and increase of early strengths, caused by higher content of alite, increased sulfate modulus and higher content of soluble alkalis.

1STANĚK Theodor, RNDr., Ph.D., Research Institute of Building Materials, JSC., Hněvkovského 65, 617 00 Brno, Czech Republic, [email protected] 2SULOVSKÝ Petr, RNDr., Ph.D., Department of Geology, Faculty of Science, Palacký University, tr. 17. listopadu 12, 771 49 Olomouc, Čzech Republic, [email protected]

INFLUENCE OF RAW MATERIAL’S PARAMETERS ON THE CLINK ER’S GRINDABILITY AND CEMENT QUALITY .

Soumaya Ibrahimi1, Nejib Ben Jamaa1, Mohamed Bagane2

1 Environment Catalyses and Analyzes of Processes Unit Research (ECAP), National School of Engineers of Gabes, Tunisia.

[email protected] 2 Applied Thermodynamics Unit Research, National School of Engineers of Gabes, Tunisia.

[email protected]

ABSTRACT . The aim of the present research is to improve the manufacturing conditions of cement and therefore its quality. For this purpose, various reference samples of clinker were produced in the normal manufacture’s conditions considered by the Company of Cement of Gabes, then compared to other samples which are variable in the Lime Saturation Factor (LSF) and the raw material’s fineness. All the samples are analyzed by XRF, DRX and optical microscopy including a study of measurement of clinker’s crystal sizes. Besides, tests of compressive strength were made after 2, 7 and 28 days. Finally, a study of clinker’s grindability enabled us to evaluate the probability of grinding of these samples. In all cases, the best clinker is the one that has a vintage’s fineness close to 13-15% for the refusal of 100 µm. This latter gives a well-formed clinker nodules, well homogenized phases and indicating a good quality of cement.This clinker presentsalso the best grindability.

RESUME. Le but de ce présent travail de recherche était l’amélioration des conditions de fabrication du ciment ainsi que sa qualité. Pour cet objectif, divers échantillons du clinker de référence ont étés produits dans les conditions de fabrication normales considérés par la société des ciments de Gabès puis comparés à d’autres échantillons variables au niveau du facteur de saturation en chaux (LSF) et de la finesse du cru. Tous ces échantillons ont étés analysés par fluo X, par DRX et par microscopie optique incluant une étude de mesure de tailles des cristaux du clinker. Par suite, des essais de résistance à la compression ont été faits à 2, 7 et 28 jours. Enfin, une étude de broyabilité du clinker nous a permis d’évaluer la probabilité de broyage de ces échantillons. L’interprétation des essais a montré que le meilleur clinker est celui qui a une finesse du cru proche de 13 à 15 % pour le refus de 100 µm. Ce clinker donne des nodules bien faits avec une distribution homogène de ces phases. Il présente aussi, une meilleure surface spécifique de Blaine et une bonne résistance à la compression et aptitude au broyage.

New Findings on Early OPC Hydration using G-Factor Rietveld Refinement of XRD Data Juergen Neubauer, Friedlinde Goetz-Neunhoeffer, University Erlangen-Nuernberg, GeoZentrum Nordbayern, Mineralogy, Erlangen, Germany. E-mail: [email protected]

The quantitative phase analysis during early hydration (24h) of Ordinary Portland Cement (OPC) is challenging due to the presence of variable amounts of different amorphous phases and water [1]. For some phases which are crystalline like monosulphate 14-hydrate structural data are not available. Classical use of Rietveld refinement does not deal with that challenge because the calculation of fitted phases is always normalized to 100 wt.-%. The use of an internal standard is not appropriate due to the known filler effect on the hydration of the OPC. Therefore a remastered external standard method using the G-factor can be employed [2]. We made use of Silicon as an external standard material. The G-factor can be derived from equation 1:

Eq. 1 with: SSi = Rietveld scale factor of silicon ρSi = Density of silicon VSi = Unit-cell volume of silicon cSi = Silicon content(100 wt.-%) µ*

Si = Mass attenuation coefficient (MAC) of silicon

By determination of that G-factor any single phase might now be calculated from the equation 2 [3]:

Eq. 2 cj = sjρ jVj

2µ*SAMPLEG

Data needed can be extracted from Rietveld results. Only the µ*SAMPLE has to be calculated from the chemical composition which was determined in our investigation by XRF of the dry cement and the amount of mix water. Using that technique we followed the hydration reaction of OPC during the first 24h after contact with water. The quantitative data show an enormous accuracy with errors smaller than 0.1 wt.-% within one preparation. Main advantage of the method is the independent phase determination of any phase without normalization to 100 wt.-%. These accurate phase content was compared to the heat evolution of the cement measured by isothermal calorimetry. The multiple heat flow events in the pattern could be assigned with the help of the quantitative phase evolution. In a next step heat flow (HF) patterns were calculated from the quantitative phase data using equation 3.

Eq. 3 with

= Derivative of the phase content from G-factor ΔHR = Enthalpy of reaction

Heat flow calculated from the change of phase content during hydration time determined by G-factor analyses fit very well the measured heat flow curves. [1] D. Jansen, Ch. Stabler, F. Goetz-Neunhoeffer, S. Dittrich, J. Neubauer, Powder Diffraction 2011, 26 (1), 31-38. [2] D. Jansen, F. Goetz-Neunhoeffer, Ch. Stabler, J. Neubauer, Cement and Concrete Research 2011, 41, 602-608. [3] B.H. O´Connor, M.D. Raven, Powder Diffraction 1988, 3, 2-6.

si

sisisisi c

VsG*2µρ

=


QUANTIFICATION OF CEMENTS BY RIETVELD-FULL PATTERN METHODS By: Thomas Witzke PANalytical B.V. Lelyweg 1,NL-7602 EA Almelo, The Netherlands X-ray techniques get a more and more important role in the cement manufacturing process. Especially the successful attempts to reduce the CO2 emissions is a major task in the cement industry for the 21st century. One fast achievable step for the reduction of the emissions is the production of blended cements and composite cements. The quantification of components or phases in these cements is necessary for the production and to achieve a constant quality. The various possibilities of the quantification of these cements by Rietveld-full pattern methods, including the determination of the amorphous content, is demonstrated.

Application of Cryo Scanning Electron Microscopy for the Investigation of Early OPC-Hydration M. Fylak1, H. Pöllmann2 1 Schwenk Zement KG, Karlstadt, Germany 2 Martin-Luther-Universität, Halle, Germany Advanced Cryo-preparation techniques open new ways for SEM investigations on hydrating cementitious systems. Common SEM analyses are not practicable at early hydration times because of the hydrous or liquid state of cement pastes. Preparation and analysis of older specimens often cause a formation of artefacts. The Cryo-preparation allows setting liquid, beam and vacuum sensitive specimens into a stable state by shock-freezing. Thus this method enables proper SEM preparations for all kinds of cementitious systems. Fast freezing processes allow sample preparations at very low hydration times and high resolution imaging of cement particles and hydration products. Already after a few seconds of reaction investigations of crystal structures, characterisations of microstructure and EDX analyses are possible. The article shows results of Cryo-SEM investigations combined with in-situ XRD and isothermal Heat-Flow Calorimetry. The different methods are combined for early time hydration studies of Portland cements from one minute to three days reaction time. Results are crosslinked to receive detailed information about microstructure, phase development and hydration kinetics. The focus lies on very early hydration products (first minutes), changes in Ettringite morphology, AFm formation and C-S-H microstructures. Applications and possibilities of Cryo-preparation techniques are discussed.

Use of X-ray Diffraction to Investigate the Early Stiffening of Cement Pastes

Terrence Ramlochan1* and R. Doug Hooton1

1Dept. of Civil Engineering, University of Toronto, CANADA 2Nicolas J. Popoff

2St. Marys Cement, Detroit, MI, USA * Deceased

Abstract X-ray diffraction analysis with quantitative Rietveld analysis was used to determine the cause of early stiffening of portland cements that were also associated with setting problems of concrete in the field. The mineral phases in the cement that promote early stiffening and the early hydration products that form in the cement paste, which are responsible for the loss of plasticity, were identified and quantified. It was found that cements with high contents of K2O, syngenite was precipitated in the first few minutes leading to more persistent early stiffening. When calcium langbeinite was present in the cement, the formation of syngenite in the first few minutes of hydration seemed to be strongly favoured to the extent that much of the initially solubilized sulphate was consumed and the aluminate reaction was not adequately controlled.

1 Corresponding author: email [email protected]; Tel. 1-416-978-5912

Nanoscale Building Material Characterization by means of High-Resolution SEM Imaging Techniques

B. E. Möser

F. A. Finger-Institute for Building Materials Science, Bauhaus-University Weimar, Germany

Two types of microscopes namely a FEI XL-30 ESEM-FEG and a FEI Nova NanoSEM 230, were

used. These devices are capable of different high-resolution imaging and analytical techniques (EDS,

EBSD) in order to characterize water containing and charging building materials. In this field the

environmental-SEM (ESEM) technology in connection with high-resolution electron microscopy is

especially important, because water vapor can be used as gas in the sample chamber. The ESEM-

FEG can operate under a high water vapor pressure up to 13.3 mbar. By means of a Peltier stage the

in-situ characterization of dynamic processes such as crystallization, dissolution, hydration (e. g.

calcium sulfate hemihydrates) as well as a quasi continuous screening of the microstructural

development of fresh cement pastes etc. become possible. Comparative studies between

conventional high vacuum and ESEM conditions show that the water containing microstructures and

phases are changed in their morphologies and their chemical compositions. This is caused by loss of

capillary, adsorptive and chemically bound water under high vacuum conditions. The above

mentioned process even leads in some cases to the destruction of the lattice structure. The mineral

ettringite e. g. has 32 molecules chemically bound water and loses approximately 20 molecules in

high vacuum.

The Nova NanoSEM 230 combines magnetic immersion lens technology with ESEM technology.

As shown in Fig.1 the combined effect and the usage of a Helix gaseous secondary electron detector

[1] yields unique high resolution low vacuum characterization capabilities of insulating samples in a

water vapor environment under low voltage conditions (smaller than 5 kV). Low energy electrons

reduce beam penetration and optimize the amount of surface information carried by the signal. Only

by deploying very low accelerating voltages of smaller than 1.5 kV it becomes possible to

distinguish between the C-S-H phases and the pore solution in the microstructure of cementitious

materials.

This microscope can also be used as a cryo-SEM for the investigation of aqueous samples in high

vacuum environment. The high pressure freezing technique used in this context has been adapted

from life sciences [2] to satisfy the needs for building material research. The cryo-SEM, the low

vacuum SEM (up to 1.6 mbar) as well as the ESEM (up to 13.3 mbar) methods have their own

merits and are helpful when they are used together. High resolution, low-voltage SEM (LV-SEM) is

also a powerful tool for studying very dense and compact microstructures of ultra-high performance

concrete (UHPC [3], Fig. 2) as well as the nano-scale phases in it. Another aspect is the visualization

of nano-sized reactive materials such as silica fume (as shown in Fig. 3), aerosol, nanogel, carbon

nanotubes, metakaolin (as shown in Fig. 4), C-S-H-seeds and their reaction behavior in the

cementitious matrix.

Because LV-SEM provides images having a clear topographic contrast even on specimens

containing phases with low density, such as hydrates, the confusion of structural overlap does not

occur. Furthermore, in microanalytical measurements the application of the LV-SEM mode reduces

the excitation volume of the electrons up to a range of smaller than 500 nm and achieves a better X-

ray emission for light elements.

References

[1] B.L. Thiel et al., Microsc. Microanal. 10 (Suppl. 2) (2004) 1058.

[2] H. Schatten et al., Biological low-Voltage Scanning Electron Microscopy, Springer

Science+Business Media, LLC, New York, 2008

[3] B.E. Moeser et al., 3rd

International fib Congress and Exhibition, Washington DC, 2010.

FIG. 1. Artefact-free low voltage, low vacuum

imaging of C-S-H phases - the hydration product

of C3S – by means of a Helix detector.

FIG. 2. UHPC microstructure after 2d hydration

time; low voltage, low vacuum imaging using a

Helix detector, notice left: matrix enlargement.

FIG. 3. Direct comparison of a pozzolanic

reaction in progress: (left) silica fume particle

with signs of dissolution and right embedded in

portlandite aggregate in its original state.

FIG. 4. Dissolution structure on the surface of

highly reactive metakaolin due to the pozzolanic

reaction in OPC after 7 days hydration time.

Synthesis and characterization of nanoscale hydraulic high reactive phases

of Portland cements and calcium aluminate cements

Bastian Raab & Herbert Pöllmann

Contact: [email protected]

High sintering temperatures of about 1450°C (OPC) and 1500°C - 1600°C (CAC) are necessary to pro-duce Ordinary Portland Cements (OPC) and Calcium Aluminate Cements (CAC). Limestone is the main raw material for the production of these cements. Due to the high sintering temperatures and the decar-bonation of CaCO3 significant amounts of CO2 are produced (0,63 tCO2/tOPC). As a consequence, process parameters were optimized, latent-hydraulic raw materials were added to the cement and alternative raw and waste materials were used for the cement production. Further, the production of cements with lower limestone content was investigated and the re-use of the dehydrated cement fraction from old concrete tested as an hydraulic binder.

The forming of OPC and CAC phases in common industrial production by grinding and homogenising of the raw materials is very well investigated. The starting materials are better homogenised by the use of some alternative raw and waste materials for the cement production or the dehydration of hydrated ce-ment compared to traditional production. Therefore, it is necessary to gain a better understanding of the forming of cement phases by using well homogenised raw materials and to understand their hydration behaviour.

As a consequence, the forming of OPC and CAC phases of very well homogenised raw materials was studied. The phases occurring at low temperatures were characterized and the hydration behaviour of these phases was determined. Different sol-gel, self-combustion and polymeric precursor methods were used for the synthesis of the cement phases. Some of these phases were synthesised at significant lower sintering temperatures and with a much higher hydraulic reactivity compared to the phases produced by the traditional high tempera-ture synthesis method. The high temperature modification α´L-C2S was produced at 650°C with total heat liberation 8 times higher than the β-C2S produced at 1100°C. High reactive iron rich Brownmillerites can be synthesized at 700°C. The metastable calcium aluminates C5A3 and CA (orthorhombic modification) crystallise at 900°C. Due to the high hydraulic reactivity all these phases are completely hydrated after the main hydration reaction.

In summary it can be stated that metastable phases and modifications were produced with less CaO in their chemical formulae and at lower sintering temperatures compared to the conventional production route. The hydraulic reactivity of these phases is high enough to be used as hydraulic binders.

Reasons for the formation of these phases at lower temperatures are the better homogenisation smaller particle and crystallite sizes of 10 nm to 50 nm of the starting material. The small crystallite size leads to a decrease of the decarbonation temperature of CaCO3 down to 550°C. The phase forming is faster be-cause the diffusion on grain boundaries is faster than inside the crystal lattice. Such is also the reason for the higher hydraulic reactivity of the cement phases. By spray drying it was possible to produce high reac-tive α´L-C2S and CA (orthorhombic modification) at the same low sintering temperatures as using the polymeric precursor method. The optimised parameters of the spray dryer allow the production of other oxides and also metallic powders with grain and crystallite sizes of 10 nm to 50 nm in higher quantity (Up-scaling). By using the optimised synthesis parameters different metastable phases can be produced at low sintering temperatures. Such enables the production of other metastable phases with new properties.

Microscopic analysis of secondary reaction products in concrete incorporating sulphide-bearing aggregates

A. Rodrigues (a), B. Fournier(a), and J. Duchesne (a)* aCentre de Recherche sur les Infrastructures en Béton (CRIB), Université Laval,

Geology and Geological Engineering Dept., 1065 ave de la Médecine, Québec, QC, G1V 0A6 Canada [email protected] [email protected] *Corresponding author. Tel.:+1-418-656-2177 E-mail address: [email protected] (J. Duchesne)

In the Trois-Rivières area (Quebec, Canada), concrete deterioration of houses and

commercialbuildings seems to be related to the use of sulphide bearing coarse aggregates. The

problematic aggregate is ananorthositicgabbro containing different proportions of sulphide

minerals (pyrrhotite, pyrite, chalcopyrite, and pentlandite), the pyrrhotite being the most

abundant sulphide mineral.

As it is known, the iron sulphide minerals react in the presence of humidity and oxygen resulting

in an oxidation reaction. This reaction leads to the formation of secondary products that have

higher volumes than the original sulphide minerals. When these sulphidesare enclosed in the

concrete aggregates, the oxidation products can promoteconcrete expansion. Moreover, the

oxidation reaction generates sulphate ions that can react with Portland cement phases to

precipitate gypsum and ettringite, products that arealso responsible from concrete expansion and

cracking. In order to study these mechanisms,different sulphide mineral samples , namely,

pyrrhotite (from the Trois-Rivières aggregate), magnetic pyrrhotite, pyrite, chalcopyrite and

pentlandite were submitted to different conditions of temperature (4°C, 21°C, 38°C and 60°C),

relative humidity (60% and 80%) and they were submitted to wet/dry cyclesin two oxidizing

solutions with different pH (bleach (pH:11) and hydrogen peroxide (pH:6)). After three months

of reaction,all samples were observed by stereomicroscope and scanning electron

microscopecoupled with an energy dispersive x-ray spectrometer (SEM/EDS) in order to identify

the generated oxidation products.

This study is the starting point for further studies that will lead to the understanding of

deterioration of concrete containing sulphide-bearing aggregates.

Use of SEM and XRD for characterisation of the engineering properties of a new CMEM’s containing cementitious fillers

Shakir Al-Busaltan1 and Hassan Alnageim2

1 Postgraduate Student, School of Built Environment, Liverpool John Moores University, [email protected] .

2 Professor of Structural Engineering, Director of studies, School of Built Environment, Liverpool John Moores

University, [email protected] .

ABSTRACT

Cold Bituminous Emulsion Mixtures (CBEM’s) offered an environmental friendly and cost effective alternative for pavement of highways and air field, if its engineering properties could be improved. The effects of Fly Ash (FA) on the engineering properties of CBEM’s containing cementisious fillers were studied by replacing of traditionally mineral filer with fly ash and new cementitous fillers. Results indicate that the engineering properties namely indirect tensile stiffness modulus (ITSM) and Creep Stiffness (CS) increased as the percentage of FA increased.

Moreover, used of the FA is significantly minimized the total curing period to an acceptable time by the road engineers to gain the ultimate strength of the CBEM’s. However, with 5.5% replacement of the traditionally mineral filler by FA, the ITSM and CS were about 6 and 26 times respectively better than the traditional CBEM’s. FA functioned to fill the pores, absorb the water and develop a secondary binding of the aggregate besides the binding associated from the bitumen residue. So, the pore filling and development of the secondary binding using SEM and XRD techniques is studied in this paper.

INTERACTION OF POLYCARBOXYLATE-BASED SUPERPLASTICIZERS WITHCEMENTS : SYNTHETIC CALCIUM CARBONATE AS A MODEL TO INVESTIGATE

THE STRUCTURAL EVOLUTION OF C-S-H.

M. Dragoni, A. Lo Presti, T. Cerulli, A. Biancardi, E. Moretti, D. Salvioni


ABSTRACT

Nucleation, growth and aggregation of the C-S-H germs play an important role in the building of anetwork with the development of the mechanical strengths. Because of the complexity of thecement systems it can be useful to apply a model to investigate how these mechanisms work.

During the hydration of a Portland cement a sulphoaluminate phase forms together with a “gel”made up of water, silicon and calcium.

The implement of a new algorithm to interpret QXRD signals clearly proves that the presence of asuperplasticizer influence the production and the shell-life of the intermediate “gel”. Someplasticizers increase the hydrated mass and stabilize it actually beyond the point of saturationwithout flocculation. On the other hand some other polymers slow down the “gel” production.According with their own characteristics, they act with a different dispersion mechanism as regardsto the polymer in use.

In this paper, a synthetic calcium carbonate has been used as a model to study the dispersionmechanism of the superplasticizers. As a matter of fact, during the early stages of its formation, thisphase develops an amorphous suspension similar to the one observed during the hydration of thePortland cement. In particular some similarities have been highlighted on the behavior of the twosystems: calcium carbonate and C-S-H.

DETERMINATION OF WATER TO CEMENTITIOUS (W/CM) BINDER RATIOS BY THE

USE OF THE FLUORESCENT MICROSCOPY TECHNIQUE IN HARDENED CONCRETE

SAMPLES: PART II.

Dr. Ted Sibbick and Callie LaFleur

W.R. Grace & Co, Cambridge, MA, USA, [email protected].

Lawrence R Roberts

Roberts Consulting Group, Acton, MA USA, [email protected]

ABSTRACT

The close relationship between the water to cement (w/c) ratio of a hydrated cement matrix and

its capillary porosity, and by association the intensity of fluorescent light in a particular sample

impregnated with fluorescent epoxy, is well documented. It is also generally reported that with

28-day old concrete samples hydrated under normal conditions this relationship is valid for w/cm

ratio assessments between 0.35 and 0.70. The first part of this investigation (Sibbick et al. 2007)

reported on the comparison of a series of new reference concrete mixes of constant cementitious

content and differing water to cementitious ratios (0.35 to 0.70), which were compared to an

older series of standard reference concretes (2001). Comparison of fluorescent resin impregnated

thin sections of both these sample sets using a light intensity-based image analysis software

system showed that there was a good broad correlation of light intensity (fluorescence) to the

water to cementitious ratio between the two sets of concrete thin sections. This confirmed the

reproducibility of the technique in different laboratories / locations and that no rapid aging effect

of the fluorescent resin existed.

Natural variability within the cementitious pastes from the 2006 samples induced some concerns

regarding the reproducibility of the technique and accuracy with larger mixes. Further, there

remained strong indications that some of the reference sets containing SCM’s were consistently

brighter than observed in the PC only mixes.

Therefore, a third set of reference samples were produced in 2011 to the same mix designs as

used in the original 2001 mixes, but with local materials, in a laboratory controlled environment.

With the increasing use of other SCM’s, it was considered useful to see what effects (if any)

different cementitious replacements (and levels) would have on fluorescence intensity. Materials

examined include Type F and C fly ashes, slag, silica fume, metakaolin, and a ternary mix of

Portland cement, slag, and type F fly ash.

The main conclusion of this additional work is that the fluorescence technique remains a valid

and reliable tool for the determination of water to binder ratio of hardened concrete over the

range 0.35 to 0.70, regardless of the mix constituents, providing proper references are employed.

The variations observed between the Portland cement only references and the other SCM

containing mixes are clearly apparent when the samples are produced at 28 days of age; probable

causes of these variations are discussed. The fluorescence technique remains a highly useful tool

to the concrete Petrographer in the determination of w/cm ratios in hardened concretes.

Keywords: Fluorescence Microscopy, Water to cementitious ratio determination,

Hardened concrete, Reference samples.

mailto:[email protected]

Historic lime-binders: an example of 19th century Dutch plain concrete

H. A. Heinemann, Faculty of Architecture, Delft University of TechnologyO. Copuroglu Faculty of Civil Engineering and Geosciences, Delft University of Technology

AbstractBefore the general acceptance of Portland cement as the main binder for concrete structures in the late 19th century, other, locally available binders were occasionally used. In the case of the Netherlands, which did not produce Portland cement, traditional lime-based binders were not uncommon. With a strong tradition of trass production, trass-lime binders were used for hydraulic concrete structures as well. For Dutch defense works such binders were commonly used for plain concrete structures in the middle and late 19th century in the Netherlands, often in combination with broken bricks as coarse aggregate.A better understanding of the properties of such binders is relevant as historic concrete structures are currently reviewed as part of the cultural heritage, not only in the Netherlands. In practice, lack of knowledge on the application, identification and properties of less known binders such as lime and trass applied for concrete can be noticed. However, detailed material characterization is necessary for correct damage diagnosis and the development of compatible repair mortars. Additionally, such information is of historic relevance.

In this paper, the possibilities of the characterization of Dutch plain concrete dating from the middle of the 19th century made with broken bricks and a lime based binder will be discussed. A concrete example from the historical Dutch defense line will be presented and its microstructure will be characterized by microscopical and microanalytical techniques.

Identification of Mineralogical Changes towards Advanced Reactivity of Fly Ashes for Mechanical Activation

Monower Sadique2, Hassan Al-Nageim1

1Professor of Structural Engineering,Head of Liverpool Centre for Materials Technology, School of the

Built Environment, Liverpool John Moores University, UK. E-mail: [email protected] 2 PhD Researcher, School of the Built Environment, Liverpool John Moores University, UK.

E-mail: [email protected]

Abstract

Contributing an improved capability to less reactive pozzolanic materials to react with other materials in presence of water is vital for accelerated hydration. Mechanical activation is one of the most widely used techniques to achieve this by reducing crystallinity and/or increasing the amorphousness of the reacted materials. This study will investigate the changes in terms of reactivity for mechanical activation of a number of possible sustainable industrial waste to be used as supplementary cementitious material. Scanning electron microscopy (SEM), x-ray diffraction (XRD), x-ray florescence spectrometry (XRF), thermo gravimetric analysis (TGA), Brunauer, Emmett and Teller (BET) surface area measurement and laser diffraction particle size analyser has been used to characterise the mineralogical improvement.

Key word: Waste, Mineralogical properties, Reactivity, Amorphous, Pozzolanicity,

Abstract for the 34th

ICMA Conference, Halle, Germany

PYRITIC HEAVE IN IRELAND: THE ROLE OF PETROGRAPHY

By: Fred H. Shrimer, Golder Associates, Vancouver Canada

Alan Bromley, Alan Bromley Consultant, Ltd., Cornwall, U.K.

Hundreds to thousands of cases of heave of structures have been

attributed to the presence of pyrite-bearing aggregate in Ireland in

recent years. Leading to numerous lawsuits, expenses in the millions of

Euros, and untold emotional toll on thousands of people and their

families, this problem was defined through the use of petrography of

the aggregates at the center of the problem.

This paper examines the use of petrography in the investigations that

were undertaken, and discusses the means that were used to assess

the nature of the problem, as well as the differences found in the Irish

cases of heave compared with those in other countries. In addition,

due to the fine-grained nature of the aggregates, we look at the

complementary analytical techniques that were used to augment the

petrography.

B

INSTITUTE RECOGNISED

27/03/2012

Thirty-Fourth International Conference on Cement Microscopy

Study of pop-outs in concrete caused by secondary In Flanders (north of Belgium), a shortness of gravel is at hand. committee” was established to financially support projects in order to find alternatives for gravel in all its applications. With this subsidy, VITO (Flemish Institute for Technological Research) and BBRI (Belgian Building Research Institute) worked together on the resethe mechanisms of pop-outs in concrete and granulates, i.e. residues coming from different industries such as bottom ashes, slag, ... kind of research is required in order to be able to estimate the riin concrete. Once the causes identified, directives can be stated to minimize the risks of popouts. Pop-outs are esthetical and structural unwanted holes that appear on the concrete by flied off surface material. The ejectionaround an aggregate as a result of physical or chemical reactions.After mineralogical, chemical and to make concrete samples. Threeorder to evoke pop-outs in the concrete. Of the four different tested aggregatesdeveloped tests. Examining the core of the created pophydration of calcium oxides proved to be the causeshowed also an intense fissuring from which the origin could be revealed by SEMSeveral attempts to make thin sectioncomponents and up till now the cause of the fissuring remains a question mark. Veerle BAMS ________________________________________"Mineralogy & Microstructure" laboratory"Materials" division BBRI | Belgian Building Research InstituteAvenue P. Holoffe, 21 B - 1342 Limelette T +32 2 655 77 11 | F + 32 2 653 07 29

E [email protected] www.bbri.be _____________________________________

BELGIAN BUILDING RESEARCH INSTITUTE

NSTITUTE RECOGNISED IN APPLICATION OF THE DECREE LAW OF 30 JANUARY

Fourth International Conference on Cement Microscopy

abstract

outs in concrete caused by secondary aggregates

In Flanders (north of Belgium), a shortness of gravel is at hand. Therefore, the “Research established to financially support projects in order to find alternatives for

With this subsidy, VITO (Flemish Institute for Technological Research) and BBRI (Belgian Building Research Institute) worked together on the rese

outs in concrete and of the nature of the damaging secondary , i.e. residues coming from different industries such as bottom ashes, slag, ...

kind of research is required in order to be able to estimate the risks when using stony residues in concrete. Once the causes identified, directives can be stated to minimize the risks of pop

outs are esthetical and structural unwanted holes that appear on the concrete by flied off surface material. The ejection of concrete pieces is caused by the pressure that is built up around an aggregate as a result of physical or chemical reactions. After mineralogical, chemical and micro structural analysis, the selected aggregates

Three tests were developed to which the samples were outs in the concrete.

aggregates, only one lead to pop-outs and this with only one of the Examining the core of the created pop-outs with the electron microscope, the

proved to be the cause. Other than pop-outs, the damaged samples showed also an intense fissuring from which the origin could be revealed by SEMSeveral attempts to make thin sections of the concrete samples failed because of the hard slag

and up till now the cause of the fissuring remains a question mark.

________________________________________ "Mineralogy & Microstructure" laboratory

Belgian Building Research Institute

+ 32 2 653 07 29

_____________________________________

NSTITUTE ANUARY 1947

Fourth International Conference on Cement Microscopy PAG. 1/1

aggregates

Therefore, the “Research established to financially support projects in order to find alternatives for

With this subsidy, VITO (Flemish Institute for Technological Research) and BBRI (Belgian Building Research Institute) worked together on the research of

the nature of the damaging secondary , i.e. residues coming from different industries such as bottom ashes, slag, ... . This

sks when using stony residues in concrete. Once the causes identified, directives can be stated to minimize the risks of pop-

outs are esthetical and structural unwanted holes that appear on the concrete by flied of concrete pieces is caused by the pressure that is built up

aggregates were used samples were exposed in

outs and this with only one of the s with the electron microscope, the

outs, the damaged samples showed also an intense fissuring from which the origin could be revealed by SEM-analysis.

s of the concrete samples failed because of the hard slag and up till now the cause of the fissuring remains a question mark.

INTERACTION OF POLYCARBOXYLATE-BASED SUPERPLASTICIZERS WITHCEMENTS : EFFECT OF THE POLYMER ON STRUCTURAL REARRANGEMENT OFTHE C-S-H GEL DURING THE HYDRATION OF PORTLAND CEMENT

M. Dragoni, A. Lo Presti, T. Cerulli, A. Biancardi, E. Moretti, D. Salvioni


ABSTRACT

The development and the implement of a new algorithm to interpret QXRD signals clearly provesthat polymers are able to influence the hydration of the C3S in a OPC based system.

During the hydration of a Portland cement, a sulphoaluminate phase forms, together with anintermediate “gel” made up of water, silicon and calcium. This “gel”, that can be consideredamorphous, evolves and structures itself and, when it gets to a saturation point, becomes C-S-Hwith the development of portlandite and mechanical strength.

A trace element, Methylene Blue has been used to follow the structure evolution of the hydrates.The experiments carried out in UV-VIS spectroscopy find a confirmation in the qualitativeevidences from the ESEM analysis, in the quantitative data from QXRD analysis, in size dimensionanalysis and in chemical analysis.

AN ON-LINE IN-SITU ASR INVESTIGATION OF THE PYLONS OF AN 80 YEARS

OLD CONCRETE BRIDGE

Peter Laugesen Pelcon Materials & Testing ApS

ABSTRACT Prior to rehabilitation of the pylons of a 1935 concrete bridge exposed to marine waters, a large scale testing program was performed. This included in-situ testing and core analysis documenting local in-situ-stress, compressive strength, chloride contamination, cracking, condition of re-bars and concrete microstructure analysis, including assessment of ASR. Additional to and supporting the findings of this program was performed endoscopic analysis of a high number of horizontal bore holes Ø: 35mm, drilled to lengths of 3-5m into the mass concrete, allowing for ‘full size’ condition evaluation. Selected endoscope videos and results of the endoscope analysis are presented, showing the potential and limitations of the method, especially relevant for bulk concrete structures such as concrete dams, anchor blocks and pylons. The presentation is intended to open a discussion on representative sampling and analysis during condition assessment, as well as sharing with you the fantastic experience of moving around inside mass concrete, surrounded by curtains of ASR-gel.

ANALYTICAL AND TECHNOLOGICAL STUDY OF A GROUT USED FOR WATERTIGHTING OF DAM UPSTREAM FACE

F. Cella, C. Maltese, C. Pistolesi, D. Salvioni, A. Bravo, T. Cerulli, E. Moretti,


ABSTRACT

Being water tightness and stability the two main requirements a dam has to meet, the dam wall

must have sufficient strength to firstly, stand permanently under its own weight and secondly,

resist the water pressure in the lake upstream of the dam. In order to reach the performance

required, construction methods have evolved over the years. The development of Roller

Compacted Concrete (RCC) caused a major shift in the construction practice of mass concrete

dams and embankments. RCC differs from conventional concrete principally in its consistency

and in the method of placing and compacting. For effective consolidation, the concrete mixture

must be dry enough to prevent sinking of the vibratory roller equipment but wet enough to

permit adequate distribution of the binder mortar in concrete during the mixing and vibratory

compaction operations. Dams need obviously an impermeable upstream face, which can be

obtained by different techniques, among which the Grout Enriched Roller Compacted Concrete

(GERCC). This technology consists in the addition of a grout to the uncompacted RCC to

increase both workability and density vibration by immersion vibrators.

Mapei studied a specific grout formulation for this type of application, which could give

better performances compared to the simple cement-water mixture.

The technological performances of the product under investigation have been evaluated by

measuring fluidity after mixing, open time, stability to segregation of the grout besides elastic

and mechanical characteristics of GERCC. Being the mixing and curing conditions of this

binder quite different from a standard cement-based product, it was particularly interesting to

look at the microstructure and mineralogical composition of the hydrated paste, with the aim to

find a relation with its macro-properties. Making this exercise we took advantage of analytical

techniques, such as Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), Thermo-

Gravimetric Analysis (TGA).

The use of a recycled glass powder and a foam glass containing metakaolin in different binder systems

Michael Schmidt, Herbert Poellmann & Armin Egersdoerfer Contact: [email protected]

In this investigation the use of Mikrover® and Metapor® in different binder systems was investigated. Mikrover® is a reactive glass meal made by Dennert Poraver GmbH, Germany. This material is made of recycled and finely ground bottle glass. This glass is also used in the production of foam glass which is used in numerous applications of the building industry. In the production process of this foam glass kaolin is added in order to prevent coagulation of the particles. Throughout the process the kao-lin is transformed to metakaolin which is a highly pozzolanic material. In the process the metakaolin is enriched with foam glass particles as well as glass particles from the raw material (Fig.1, 2). The re-sulting product is called Metapor®. The possible use the glass meal was investigated on Cement prisms of four mixtures of a regular CEM I 42,5R and Mikrover®, according to German DIN regulations [SCHMIDT ET AL 2009]. The added glass powder (<36µm) values ranged from 2,5% to 7,5%. The sam-ples were stored under humid conditions in a climate chamber at 20°C. The compressive and bending tensile strength development of these standardized concrete prisms was investigated over a time pe-riod of one year in the interval: 1, 2, 7, 14, 28, 90, 180, 360 days. Prior to the strength investigations the properties of the glass powder and the cement were determined. The use of Metapor® was inves-tigated on Mortar prisms prepared from calcium hydroxide and Metapor® [SCHMIDT ET AL 2011]. Two qualities in terms of glass content of Metapor were used (10% & 25%). In the mixtures 6,25 % and 12,5% of the Metakaolin were replaced with equal amounts of Metapor®. All samples were stored un-der humid conditions in a climate chamber at 20°C. Compressive and bending tensile strength devel-opment of these standardized prisms will be investigated over a time period of one year in the interval: 7, 14, 28, 90, 180, 360 days. Prior to the strength investigations the properties of the product Metapor® are determined. The hydrated samples were investigated using XRD and SEM.

Fig.1: Ground bottle glass (Mikrover®) (x2000) Fig.2: Metapor® with an glass content of 10% (x500)

References:

SCHMIDT M., PÖLLMANN H., EGERSDÖRFER, A., (2009): „Untersuchungen zur Verwendung von Glasmehlen als Zusatz zu zementären Systemen“, Poster, 87. Tagung der Deutschen Mineralogischen Gesellschaft, Halle (Saale), S. 219

SCHMIDT, M., POELLMANN, H., EGERSDOERFER, A. (2011): “Investigation on the use of a foam glass containing metakaolin in a lime binder system”. Proceedings of the 33nd International Conference on Cement Microsco-py, San Francisco, (USA), p.1- 36

Pore structure of hardened mortars based on different cementitious materials

Thomas A. BIER1

1 Institut für Keramik, Glas- und Baustofftechnik, TU Bergakademie Freiberg, Leipziger Straße 28, D- 09596 Freiberg,

Germany, [email protected], phone +49-3731-39-3132 Fax +49-3731-39-2223

Abstract

Hardened mortars are porous materials their pore structure being developed during hydration as a

function of water binder ratio, the binders chemical reactions, time, temperature and pressure.

Different binder systems and as a consequence different chemical reactions will influence the pore

structure. Different binders or chemical systems such as Calcium Silicate Hydrate (CSH) formation,

Calcium Aluminate Hydrate (CAH) formation and ettringite formation are investigated with respect

to the developing pore structure. The water binder ration is kept constant while the temperature-

pressure conditions during hydration are varied. The pores structure and porosity is investigated by

different method such as sorption methods, mercury intrusion porosimetry (MIP) and secondary

electron microscopy (SEM).

The presented results show differences in microstructure based on the individual hydrates. This is

shown by SEM micrographs for those hydrates which can easily be identified by SEM. MIP

results give a picture of the overall porosity and are compared to the underlying chemical reactions

by using Powers approach to calculate capillary porosity.

Analyses in monument preservation - Characterisation of historical mortars and concrete by microscopy Jeannine Meinhardt & Matthias Zötzl

Institute for Diagnosis and Conservation on Monuments in Saxony and Saxony-Anhalt

In order to get information about the composition of historic mortars, in the field of

monument preservation in particular wet chemical processes and x-ray analytics are available.

However, not all issues can be sufficiently clarified using these processes. Because only small

samples can be taken from cultural heritage objects, microscopy is an important investigation

method in this field. Furthermore, this method can be used not only for identifying the binder

and aggregates, but also for illustration of structural characteristics, shrinkage cracks, damage

processes and also architectural history comparisons of different mortars. As historic

materials, mainly different lime mortars (hydraulic and non-hydraulic), Roman Cement and

Gypsum-Anhydrite-mortars need to be analyzed. A concept for a microscopy atlas is currently

being developed. The conference contribution will give insight into this project.

The figure below (1) shows stamped concrete with the presence of un-hydrated clinker relicts

in the concrete matrix. The sample has been taken from the Battle of Nations Monument

(Völkerschlachtdenkmal) in Leipzig.

Fig. 1 Un-hydrated cement clinker grains. Microscopic image, transmitted light, field of view 0.078 x 0.052 mm

Photomicrographs of Common Oilfield Cementing Additives

Tom Dealy, Halliburton

ABSTRACT Over 200 different cementing additives are available for inclusion with Portland cement to achieve the desired slurry performance under the myriad of conditions encountered when cementing oil and gas wells. Placement temperatures may range from near 32oF to >500oF and the cement slurry may be required to travel over 9 miles during placement. Operating temperatures after placement can vary from <32oF to >700oF. It is very desirable to be able to quickly identify the presence of these additives in a dry cement blend rather than performing common physical tests such as compressive strength, and total thickening time and then making assumptions as to blend content based on test response. An investigator can verify the presence of additives by studying a sample of a cement blend mounted on an oil-immersion slide and viewed at 100-200X magnification with a transmitted, polarized light microscope. It is desirable to also have fluorescence light capability to make identification of some additives easier. Staining the blend with a few drops of rhodamine B or methylene blue dye can also make identifying additives such as clays and polymers easier.

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