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European Geopolymer Network

Limoges – June, 15th 2016



PROGRAM OF THE FIRST EUROPEAN GEOPOLYMER NETWORK 9h00 Opening session

09h30 Joseph Davidovits: Geopolymers based on natural and synthetic metakaolin. A critical review 09h55 Lubica Kriskova et al.: Towards porous inorganic polymers: kinetics of the foaming process 10h20 Cengiz Bagci et al.: TEM Studies of Silicon-Based Ceramic Nano-Particles Synthesized from Sodium Geopolymers

10h40 coffee break and poster session

11h15 Marco Natali et al.: Photocatalytic activity of TiO2 degussa P25 in different geopolymer matrices 11h40 Isabel Sobrados et al.: Electrochemical behaviour of hybrid sol-gel steel embedded in carbonated and chloride contaminated alkali-activated fly ash mortars 12h05 Trudy Kriven et al.: Status Quo of Metakaolin-based Geopolymers Containing Inorganic or Biological Reinforcements

12h30 lunch and poster session 14h00 Visite of the European ceramic Center

14h30 Wallid Hajjaji et al.: Reuse of red mud and lamp glass waste in geopolymers 14h55 Silvania Onisei et al.: Slags in the binary FeOx-SiO2 and ternary FeOx-CaO-SiO2 system 15h20 Najet Saidi et al.: Recycling of geopolymer waste: influence on geopolymer formation and mechanical properties 15h45 Claudio Ferone et al.: Synergistic use of reservoir management wastes to obtain geopolymer bricks

16h10 Round table 17h30 End of the congress



LIST OF THE POSTERS P1 Elettra Papa et al.: Porosity and insulating properties of silica-fume based foams P2 Valentina Medri et al.: Tailoring and study of the porosity in geopolymer based materials P3 Marilyne Soubrand et al.: Importance of geopolymers for the valorization of various type of inorganic waste P4 Julie Peyne et al.: Improving the clay bricks production: experimental clay mixtures and geopolymer binders P5 Alexandre Autef et al.: Study of the geopolymerization rate by thermal experiments P6 Laetitia Vidal et al.: Alkaline silicate solutions properties and their effect on sand agglomeration and geopolymer formation P7 Francisca Puertas et al.: Re-use of waste glass in the preparation of geopolymer: as alternative alkaline solution and solid precursor P8 Nicoletta Toniolo et al.: Geopolymer incorporate silicate waste P8 Giamarco Taveri et al.: Fly-ash/borosilicate glass based geopolymers P9 Jihène Nouairi et al.: Using lakhouat (NW Tunisia) mine tailing in metakaolin based geopolymers P10 Ioanna Papayianni et al.: Alkali activation of high calcium by-products and applications



Geopolymers based on natural and synthetic metakaolin. A critical review Joseph Davidovits

Institut Géopolymère, 02100-Saint-Quentin, France Much of the original research into geopolymers was conducted on calcined kaolinitic clay precursors

known under the generic term of metakaolin. Although metakaolin reacts in alkaline as well as in acidic

medium, the present issue focusses exclusively on the alkaline route.

Forty years ago, in October 1975, in our CORDI laboratory (later Cordi-Géopolymère) in Saint-Quentin,

France, we were testing a new French metakaolin brand named Argical®. It was manufactured with an

advanced technology in a flash calciner instead of being roasted in a rotary kiln or a vertical multiple-

hearths oven. We discovered that this metakaolin was reacting very well with soluble alkali silicates. I

recognized the potential of this discovery and presented an Enveloppe Soleau for registration at the

French Patent Office. It was the first mineral resin ever manufactured. Chapter 1 of the book

Geopolymer Chemistry and Applications describes this major milestone. The title of the patent, Mineral

polymer, was self-evident (Davidovits, 1979). In 1983, at the Central laboratory of Lone Star Industries,

Houston, USA, we started the development of advanced cementicious materials. This research yielded

the discovery of the first metakaolin-based geopolymer cement (the cement PYRAMENT).

However, we had to test at least 10 different metakaolin brands in order to find the right product, which

would react as a geopolymeric precursor, in alkaline medium. Indeed, at that time, the bulk of the various

metakaolins was used essentially as fillers in the paper making and plastic industry. Its specific chemical

reactivity towards alkalis remained confined in the production of very special products, namely synthetic

zeolites, especially the type Zeolite A. In addition, it was striking to discover that the metakaolin sources

for zeolite manufacture were according to Breck (1974) of two types, one calcined at 550°C (low

temperature metakaolin) and the second at 925°C (high temperature metakaolin). Both metakaolins

reacted weakly compared to the metakaolin we had been working with in France. We recognized that

we had had luck when starting the geopolymer research, in Saint-Quentin. We had tested the right source

of metakaolin, from the beginning.

And we became aware of one major parameter in geopolymer science, namely the calcining temperature

of the geological kaolinitic clays. The chemical formula for kaolinite is Si2O5Al2(OH)4. From a

geopolymer standpoint we may write Si-O-Al-(OH)2 with the covalent aluminumhydroxyl - Al-(OH)2

side groups of the poly(siloxo) hexagonal macromolecule [Si2O5]n. This new structural approach has

profound consequences with regard to a better understanding of geopolymerization mechanisms. In

particular, according to the reaction:

Si2O5Al2(OH)4 Si2O5Al2O2 + 2H2O

Metakaolin results from the dehydroxylation of the OH groups in kaolinite. The reactive molecule is an

alumino-silicate oxide Si2O5Al2O2, coined MK-750 in order to pinpoint the calcination temperature.

However, in addition to temperature control, it is the kiln technology, which determines the feasibility

and production of the alumino-silicate oxide MK-750. In calcination carried out in a rigid vertical

multiple-hearths calciner, a sufficiently low water vapour pressure is maintained during the entire

roasting process, providing the desired chemical reactivity (Al in 5-fold coordination). Same for

products manufactured in a flash calciner. This is not the case for metakaolins obtained in a rotary kiln,

commercialized as Portland cement additives. Unfortunately, this later product is more and more used

in geopolymer research because it is easily available. This raises new concerns in terms of reactivity and

reproducibility of the results obtained with this raw material essentially tailored for Portland cement

applications, not for geopolymer technologies. The geopolymer chemistry was invented 40 years ago

because we had the luck to get the right geological raw material and the appropriate calcination process.

Today, there exist new methods based on the synthesis of alumino-silicates. In short, we have: -

Geopolymers based on natural metakaolins MK-750 and - Geopolymers based on synthetic metakaolins

SMK-750;

The review discusses the correlation between reactivity and calcination methods, MAS-NMR

spectroscopy, reaction mechanism and applications. The details were already published online in the

second issue of the Virtual Journal on Geopolymer Science, hosted by the

platform MaterialsToday from Elsevier. (See at http://www.geopolymer.org/news/2nd-virtual-journal-

on-geopolymer-science/).

http://www.materialstoday.com/



Towards porous inorganic polymers: kinetics of the foaming process

Kriskova, L.1,*, Denissen, J.1,2, Pontikes, Y.1

1Department of Materials Engineering, KU Leuven, 3001 Heverlee, Belgium 2Faculty of Engineering Technology, Campus Group T Leuven, 3000 Leuven, Belgium

*[email protected] The present paper deals with the synthesis of porous inorganic polymers (IP) from a secondary copper

slag and its main focus lies on the investigation of various parameters (alkali activator molarity and

curing temperature) and their effect on the kinetics of foaming. Since, it had been previously shown that

a porous IP could indeed be synthesised from this type of slag;1 the motivation of the work was to

identify the most crucial parameters influencing the foaming kinetics, as well as to find conditions under

which a stable, well developed foam could be formed, within an industrial operating environment. For

this purpose, a FeO-SiO2 based secondary copper slag was activated with Na-silicate alkali activator

with a SiO2/Na2O molar ratio varying between 1.0 to 1.4, keeping the water content steady at 75 wt.%.

Foaming was achieved by the oxidation of the aluminium in the alkaline environment, liberating H2

gas, and the subsequent gas entrapment. The temperature of the environment during foaming was

controlled by having all the installation inside a water tank with controlled temperature.

In order to determine foaming kinetics, the foaming process was recorded by means of a camera and the

height of the synthesised foam was measured every 5 sec. Results presented in Fig. 1 showed that the

SiO2/Na2O ratio had a major influence on foaming kinetic regardless of the temperature at which the

foaming was performed, e.g. for an increasing the SiO2/Na2O ratio foaming initiated later The increased

SiO2/Na2O ratio had a positive effect on the foaming itself, as could clearly be seen by comparing the

originally introduced amount of material with the final foam volume. The volume increased about 2

times for SiO2/Na2O of 1.0 but about 3.5 times for the ratio of 1.4.

40 60 80 100 120 140 160 180100

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Figure 1 : Change of the foam height over a time as a function of an activating solution at a) 20 °C

and b) 40 °C

The effect of SiO2/Na2O ratio as well as of the curing temperature on the reaction kinetics was also

evaluated by means of isothermal calorimetry. It was revealed, that the higher SiO2/Na2O ratio resulted

in slower reaction and smaller amount of released heat. This is most probably a consequence of lower

dissolution rate caused by lower Na2O content, combined with an expected higher viscosity. Similarly,

lowering the temperature of environment, resulted in later initiation of the reaction.

References 1 L. Kriskova, et al., Synthesis and characterisation of porous building materials from FeO-SiO2 based slag, 2015,

Proceedings of the 4th International Slag Valorisation Symposium, 229-237.

a) b)



TEM Studies of Silicon-Based Ceramic Nano-Particles Synthesized from Sodium

Geopolymers

Cengiz Bagci1,2 and Waltraud M. Kriven1

1Department of Material Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA 2Department of Metallurgical and Materials Engineering, Hitit University, Corum, 19030, TURKEY Recently, geopolymers (GPs) are being considered as precursors to ceramic formation.1,2 Pure sodium

geopolymers were converted to a high strength ceramic material on heating to develop their mechanical properties

for use in structural applications. Namely, NaGPs crystallized into nepheline (Na2O•Al2O3•2SiO2) plus glass, on

heating at 900-1100 °C.1 By incorporating carbon nano-powders into GPs, we have well achieved to produce

silicon carbide nano-particles.3 In this study, 9 or 18 moles of carbon nano-powder were incorporated into NaGPs

at the stage of GP resins or powdered GPs after curing to make GP carbon precursors for carbothermal reduction,

respectively by the well-known geopolymer route under ambient temperature. Subsequently, GP carbon precursors

were carbothermally reacted in an atmosphere controlled tube furnace at temperatures of 1400°-1600 °C for 2 h

under high purity argon or nitrogen (99.99%) flowing. Depending on GP preparation and carbothermal reduction

conductions, this study revealed that the formation of high yield nano-sized silicon-based ceramic powders by

confirming TEM studies by following standard analysis. Fig.1 shows TEM micrograph corresponding selected

area patterns (SAD) of SiAlON from NaGP9C by confirming ex-situ XRD.

a) b)

Figure 1 : TEM micrographs of NaGP9C heated at 1400 °C /2h under nitrogen (a) SAD pattern of the region (b).

Fig.2 represents TEM SAD patterns of the SiC converted from NaGP18C by confirming ex-situ XRD.

a) b)

Figure 2 : TEM micrographs of NaGP18C heated at 1600 °C /2h under argon (a) SAD pattern of the region (b).

The nanocrystals of these silicon based ceramics (<100 nm) with different morphologies and the crystallite were

determined by TEM corresponding SAD.

REFERENCES 1C. Kuenzel, L. M. Grover, L. Vandeperre, A. R. Boccaccini, C. R. Cheeseman, J. Eur. Ceram. Soc., 2013, 33,

251-8. 2J. L. Bell, P. E. Driemeyer and W. M. Kriven, J. Am. Ceram. Soc., 2009, 92 [3] 607-15. 3C. Bagci, G. P. Kutyla, K. C. Seymour, and W. M. Kriven, J. Am. Ceram. Soc.,2016, 1-10 DOI:

10.1111/jace.14254.



Photocatalytic activity of TiO2 degussa P25 in different geopolymer

matrices

M. Natali 1, A. Galenda 1, , S. Tamburini 1

1 National Research Council - Institute for Energetics and Interphases (CNR-IENI)

Corso Stati Uniti 4 - 35127 - Padova ITALY The use of photocatalytic self-cleaning materials in particular for building facades is of paramount importance because of their continuous exposure to air pollution, degrading their aesthetic appearance. Numerous studies have been conducted on photocatalytic coatings and photocatalytic cements, in particular by adding TiO2 nanopowders to cements [1-3]. Only very few studies exist on the formulation of geopolymers with photocatalytic activity [4,5]. This is quite surprising considering the emerging role of geopolymers as a green building material able to substitute ordinary portland cement in many fields. We here present our preliminary results on a screening of the photocatalytic activity of different geopolymer formulations, both alkaline and phosphate based ones, incorporating TiO2 Degussa P25 nano powder at different levels up to 10% weight. The photocatalytic activity was evaluated by monitoring the bleaching of ethylene blue dye spots deposited on geopolymer samples exposed to UV radiation at 365 nm in air. Comparison was made between samples having different TiO2 contents, samples kept in the dark, as prepared and treated samples. The photocatalytic activity of the examined samples ranged from 4 % to 30 % for UV exposure of 1000 min and was lower than for cement and stucco samples investigated for comparison (54% and 60% degradation respectively). In an effort to understand the observed results samples were characterized by XRD in grazing incidence and SEM-EDS.

REFERENCES: 1 A. Folli, I. Pochard, A. Nonat, U.H. Jakobsen, A.M. Shepherd and D.E. Macphee, 2010, J. Am. Ceram. Soc., 93

, 3360–3369. 2 A.R. Khataee, A.R. Amani-Ghadim M. Rastegar Farajzade & O. Valinazhad Ourang, 2011, Journal of

Experimental Nanoscience, Volume 6, Issue 2, 1745. 3 A. Strini, S. Cassese and L. Schiavi, 2005, Appl. Catal. B-Environ. 61, 90-9. 4 J.R. Gasca-Tirado et al.2012, Microporous and Mesoporous Materials 153, 282–28. 5 Yao Jun Zhang, Li Cai Liu, Yong Xu, Ya Chao Wang, De Long Xu,2012, Journal of Hazardous Materials 209–21,

146–150.



Electrochemical behaviour of hybrid sol-gel steel embedded in carbonated and chloride contaminated alkali-activated fly ash

mortars.

M. Criado 1,2, I. Sobrados1, J. M. Bastidas3, J. Sanz1

1 Materials Science Institute of Madrid (ICMM), CSIC, Sor Juana Inés de la Cruz 3, 28049

Cantoblanco-Madrid, Spain

2 Department of Materials Science and Engineering, The University of Sheffield, Sir Robert

Hadfield Building, Sheffield S1 3JD, UK

3 National Centre for Metallurgical Research (CENIM), CSIC, Avda. Gregorio del Amo 8, 28040

Madrid, Spain

Corrosion of reinforcement steel is one of the main causes of the premature degradation of

reinforced concrete structures. Thus the construction sector is very interested in the development of new

cement binder materials as an alternative to ordinary Portland cement (OPC). In this respect, the most

promising emerging approach is based on raw materials suitable for alkaline activation, essentially

alkali-activated fly ash (AAFA), which originate new binding materials known generically as alkaline

cements.

The protection of metals from their surrounding environment is usually achieved by deposition of

protective coatings on the metal surface to establish a physical barrier against aggressive ions.

The aim of this work was to study the corrosion behaviour of hybrid organic-inorganic coatings

applied on carbon steel embedded in carbonated ordinary Portland cement (OPC) and alkali-activated

fly ash (AAFA) mortars and immersed in a 3 wt% NaCl solution using electrochemical methods. The

sol-gel coatings were prepared by condensation and polymerization of TEOS/MPTS, TEOS/MTES,

TMOS/MPTS and TMOS/MTES mixtures using a molar ratio of 1.0 and deposited by dip-coating on

carbon steel substrates.

Interesting results indicate that corrosion of coated steel rebar embedded in carbonated OPC and

AAFA mortars in the presence of chloride ions was not only dependent on the type of the cementitious

system but also on the nature of reagents forming the coating. Carbon steel reinforcements are

compatible with AAFA mortars, where they show corrosion rates even lower than those recorded in

OPC mortars.



Status Quo of Metakaolin-based Geopolymers Containing Inorganic or

Biological Reinforcements

Waltraud M Kriven,2, 1University of Illinois at Urbana-Champaign, Department of Materials Science and

Engineering, Urbana,, IL USA Metakaoline-based geopolymer composites have been reinforced with a variety of inorganic or organic

reinforcements which can be categorized in terms of their dimensionality i.e. particulates, short fibers,

chopped fibers, randomly oriented longer fibers to form a permiable mat, aligned long fibers and weaves.

Table 1. Summary of Geopolymer Composites containing Inorganic Reinforcements

Reinforcement % addition Flexure strength (MPa)

Chamotte (25 m) 50 wt% 15.33

Dolomite (45 m) 20 wt % 15.92

Mica phlogopite platelets 20 wt% 11.4

Granite powder 55 wt. % 10.3

Dicalcium phosphate (DCP) 15 wt% 9.8

Hydroxyapatite bone ash 15 wt % 9.5

Alumina platelet grinding media 70 wt % 20 (40 at 1000 °C)

Alumina chopped fibers 20 wt % 20

Basalt chopped fibers (1/4 “) 10 wt % 19.5

Basalt chopped fibers (1/2 “) 10 wt % 27

Basalt felt 10 wt % 22.2

Fiberglass felt 10 wt % 5.6

Basalt strand mat 20 vol % 31

Basalt fiber weave 30 vol % 41

E-glass Leno weave 25 wt % 25.6

Carbon fiber weave 20 vol % 269

Nextel 610 alumina (8 satin weave) 50 wt% 45.8

Nextel 720 mullite +15 vol % alumina 50 wt% 46

Table 2 : Summary of Geopolymer Composites containing Biological Reinforcements

Reinforcement % addition Flexure strength (MPa)

Abaca (banana leaf random fibers) 8.0 wt% 52

Corn husk fibers 13 wt % 7.6 (7 % strain to failure)

Jute weave 30 wt % 20.5

Colombian fique / sisal (unidirectional) 50 wt % 11.4

Amazon malva (unidirectional) 5.5 wt % 31.55

Amazon curaua (unidirectional) 8.3 wt % 18.86

Amazon chopped bamboo in Amazonian clay 15 wt % 7

Cork particulates 60 wt % 2.5 (0.75 % strain to failure)

K-based Geopolymer reinforced

with chopped Saffil ® alumina fibers

REFERENCES:

W. M. Kriven, in Comprehensive Composite Materials, to be published by John Wiley, (2016).



REUSE OF RED MUD AND LAMP GLASS WASTE IN

GEOPOLYMERS

W. Hajjaji1,2, C.S. Costa1, S. Andrejkovičová1, J. A. Labrincha3, F. Rocha1 1 Geobiotec, Geosciences Dept, University of Aveiro,3810-193 Aveiro, Aveiro 3910-193, Portugal

2 Natural Water threatment Laboratory CERTE, 273, 8020 Soliman, Tunisia 3 Department of Materials and Ceramic Engineering & CICECO – Aveiro Institute of Materials,

University of Aveiro, Aveiro, Aveiro 3810-193, Portugal

Geopolymers, a class of largely amorphous aluminosilicate binder materials, have been studied

extensively over the past several decades. Incorporation of wastes and by-products, as red mud and

fluorescent lamp glass, was studied to elaborate new metakaolin based geopolymer formulations thought

sodium alkaline activation. The main raw material is metakaolin 1200S (MK) (AGS Mineraux, France),

as alumino-silicate source (geopolymer GMK).The red mud and fluorescent lamp waste glass were used

as additive at different ratio (GR; 10 and 25% for red mud and GG; 25 and 50 % for lamp glass).

The compressive strength (Figure 1) gave initial maximum values (at 1 day curing) around 8 MPa for

the standard metakaolin based products (GMK) and 10% red mud confectioned one (GR10). The amount

of RM had a variable effect on the mechanical properties of geopolymer. The resistance of sample GR25,

for instance, decreased to minimum values below 5 MPa. By extending the curing time, the mechanical

strength increased considerably from day 1 to day 28 for the samples GR10. Longer curing time

improves the geopolymerization state resulting in higher compressive strength1. Once hardened,

specimens based in fluorescent lamp glass (both 25% and 50% added) showed high compressive

strength and toughness at first stage (1 day curing) in respect to metakaolin based one (Figure 1). This

toughness tends to decrease with curing time before stabilizing at 28 days.

Table 1.Compressive strength of tested geopolymers.

Acknowledgement: The work was supported by FCT-Grant SFRH/BPD/72398/2010 co-financed by Programa Operacional Potencial Humano POPH. REFERENCES: 1 W. Hajjaji, S. Andrejkovicová, C. Zanelli, M. Alshaaer, M. Dondi, J.A. Labrincha, F. Rocha. Materials and Design,

2013, 52, 648-654.

http://www.scopus.com/source/sourceInfo.url?sourceId=17797&origin=resultslist



Slags in the binary FeOx-SiO2 and ternary FeOx-CaO-SiO2 system

as precursors for inorganic polymers

Onisei, S.*, Crijns, W., Pontikes, Y.

Department of Materials Engineering, KU Leuven, 3001 Heverlee, Belgium *[email protected]

Unlike “geopolymers”1 where the binding phase is almost exclusively an aluminosilicate with Al and Si

in tetrahedral coordination, inorganic polymers (IPs) can exhibit a wider chemistry, thus the former can

be seen as a subset of the latter.2 Of interest for the particular work are Fe-rich IPs, considering that Fe-

silicates are industrially produced by the non-ferrous metallurgy in substantial volumes and remain not

exploited yet as a secondary resource. Apart from the environmental motivation, the role of Fe in these

IPs remains obscure, thus, there is a need to provide insights in their microstructure and resulting

properties.

To address the above, 3 synthetic slags were synthesized, one in the binary FeOx-SiO2 and two in the

ternary FeOx-CaO-SiO2. After water quenching the melt, the semi-vitreous slags were characterised and

their reactivity was assessed. Subsequently, the slags were mixed with a Na-silicate solution and IPs

were formed after curing at room temperature. The properties and microstructure of these IPs were

studied by means of compressive strength measurements, FTIR and SEM, for different curing times.

Results are already presented in Figure 1, where it is demonstrated that the addition of calcium leads to

higher slag reactivity, i.e. dissolution kinetics, and increases the strength of the samples.

Figure 1 : a) Compressive strength of the inorganic polymers from the 3 synthetic slags and b)

Microstructure of the samples

REFERENCES: 1J. Davidovits, Geopolymer Chemistry and Applications, Geopolymer Institute, 2008. 2J.S.J. van Deventer, J.L. Provis, P. Duxson, D.G. Brice, Chemical Research and Climate Change as Drivers in

the Commercial Adoption of Alkali Activated Materials, Waste and Biomass Valorization, 1 (2010) 145-155.

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RECYCLING OF GEOPOLYMER WASTE: INFLUENCE ON GEOPOLYMER FORMATION AND MECHANICAL PROPERTIES

N. Essaidi1, L. Vidal, A. Gharzouni, E. Joussein2 and S. Rossignol1

1 Univ Limoges, CNRS, ENSCI, SPCTS, UMR7315, 87000 Limoges, France.

2 Univ Limoges, GRESE, EA 4330 F-87000 Limoges, France

In recent years, the growth of waste production associated with the awareness of the environmental

problems and the need of sustainable development make waste management a priority [i]. Recycling

has drawn great interest as a way to solve waste problems, reduce environmental pollutions and preserve

natural resources. In this context, geopolymer materials are a new class of binders having the advantage

of using industrial by-products and recycled waste. So far, extensive research on geopolymer has been

conducted since the last decade, the generation of geopolymer waste increases. In this context, an

innovative use of geopolymer waste is their incorporation in different geopolymer formulations which

is in accordance with the “cradle to cradle” concept. Moreover, the possibility to reuse these

geopolymers allows reducing of the amount of raw materials used. Recycling of waste and their use as

aluminosilicate sources seems to be profitable in term of economic and environmental benefits, leading

to greener manufacturing and global sustainable development.

These binders are generated from the activation of an aluminosilicate source with an alkaline solution

[ii iii]. Their formation implies the dissolution of aluminosilicate species in an alkaline environment to

form an amorphous three-dimensional geopolymer network by polycondensation reaction. Based on

such a unique structure, geopolymers may exhibit good mechanical, chemical and thermal properties

making them a promising alternative for a variety of applications [iv].

The present work aims to evaluate the suitability of using crushed geopolymer in addition or substitution

of metakaolin to produce K-based geopolymers materials. For this, the used raw materials were

characterized. Then, the feasibility of consolidated materials was evaluated. Several samples were

prepared by varying the proportion of geopolymer waste. The structural evolution of the reactive

mixtures was monitored by FTIR spectroscopy. Finally, the consolidated materials were characterized

by compression tests. A feasibility study allowed retaining 20% as the waste percentage added or

substituted to the metakaolin to still obtain geopolymer materials. Moreover, it was shown that the

incorporation of the geopolymer waste may disturb the polycondensation rate which was proved to

strongly depend on the solid to liquid ratio and the Si/K ratio of the alkaline solution. Finally,

relationships were demonstrated between the compressive strengths and the chemical compositions of

the different samples. The low reactivity of geopolymer waste can be compensated with the use of highly

reactive alkaline solution or the increase of the amount of metakaolin in the mixture.

References 1 L.A. Guerrero, G. Mass, W. Hogland, Waste Management, 2013, 33, 220-232. ii P. Duxson, A. Fernández-Jiménez, J.L. Provis, G.C. Lukey, A. Palomo, J.S.J. Van Deventer, Journal

Materials Science, 2007, 42, 2917-2933.

iii J. Davidovits, Geopolymer: Chemistry and Applications, 2nd ed., Institut Géopolymère, St-Quentin, 2008. Iv C.A. Rees, J.L. Provis, G.C. Lukey, J.S.J. Van Deventer Colloids and Surfaces A: Physicochemical and Engineering Aspects. 2008, 318, 97–105.



POSTERS



Porosity and insulating properties of silica-fume based foams

E. Papa1, V. Medri1, D. Kpogbemabou2, V. Morinière3, J. Laumonier3, S. Rossignol2

1Institute of Science and Technology for Ceramics – National Research Council of Italy (ISTEC-CNR), Via Granarolo 64, 48018, Faenza (Ra), Italy.

2Univ Limoges, CNRS, ENSCI, SPCTS, UMR7315, F-87000 Limoges, France. 3Institut PPRIME, CNRS, Université de Poitiers, ISAE - ENSMA, F 86962 Futuroscope

Chasseneuil, France The thermal resistance of geopolymers combined with the possibility to obtain lightweight structures,

exploiting the use of reactive fillers, allow the production of composite foams designed for a range of

thermo-acoustic insulating and fire-proofing applications. The use of byproducts and waste materials

combined with the choice of fast, simple and low temperature production processes are the main goals

to obtain low cost and “greener” insulating materials. Geopolymers are good candidate for this purpose,

because they may be synthetized at low temperature and from a variety of starting alluminosilicate

powders, that includes also waste materials as metallurgical slags and fly ashes [1]. Silica fume, a waste

byproduct derived from electric arc furnaces used in the manufacture of ferrosilicon or silicon metal,

was used both as starting silicate powder and pore forming agent for the production of foams. This study

shows the possibility to obtain really porous lightweight foams, with a multi-scale macroporosity, from

a potassium or sodium basic medium and metakaolin and/or silica fume starting powders. The presence

of metal silicon impurities, present in silica fume, was exploited to generate a direct foaming of the

slurry, due to the gaseous production of hydrogen caused by the oxidation, in alkaline medium, of metal

silicon [2]. A slightly elevated temperature (70°C) was enough to promote the development of hydrogen

bubbles, the increase of the viscosity and the consolidation of the foams. The reactivity of the starting

mixture and the related homogeneity greatly affected the development of the final porous structures and

the related insulating properties of the materials.

The foams were characterized in term of macro- and microstructure, porosity distribution, FTIR-ATR

spectroscopy, thermal and acoustic properties achieved. The foams showed really ultra-macroporous

structures, with roughly rounded pores and a total porosity of ≈ 80%. The low bulk densities (0.4-0.6 g

cm-3), the good thermal conductivity values (≈ 0.17 W m-1 K-1) and the acoustic behaviors make the

foams really promising as insulating materials for application, for example, in building and construction

sectors as possible insulating, heat resistance, precast panels.

Figure 1: example of the core section of a potassium silica fume based foam and related SEM microstructure. REFERENCES: 1 J.S.J. van Deventer, J.L. Provis, P. Duxson, D.G. Brice, Waste Biomass Valor. 1, 2010, 145–155. 2 V. Medri, E. Papa, J. Dedecek, H. Jirglova, P. Benito, A.Vaccari, E. Landi, Ceram. Internat. 39, 2013, 7657-7668.



Tailoring and study of the porosity in geopolymer based materials

V. Medri 1, E. Landi 1, E. Papa 1, A. Natali Murri 1, P. Benito 2, A. Vaccari 2

1 CNR-ISTEC, Institute for Science and Technology for Ceramics 2 CHIMIND, Dept. Industrial Chemistry “Toso Montanari”, University of Bologna

Geopolymers are produced by reacting an alumino-silicate powder with an aqueous alkali hydroxide

and/or alkali silicate solution. The production process in aqueous medium allows to tailor the porosity

in the nanometric to millimetric range. Water affects the intrinsic mesoporosity of the geopolymer

matrix, acting as a pore former during the polycondensation stage, while ultra-macroporosity can be

induced in the material by different methods. Hierarchical porous systems, in which mesopores are

directly connected to macro- and to ultra-macropores, can be obtained in this way.

Geopolymers are often compared with ceramics for their similar final properties arising from the

inorganic structure. The main difference, referring to the process formation of these materials, is that

ceramics are usually treated at high temperature for the final consolidation, while geopolymers have the

advantage to be consolidated through a chemical reaction that occurs at low temperature.

Methods used in the formation of porous ceramics can be adapted to obtain geopolymers with different

architectures, pore size distributions, interconnectivity, etc.; direct foaming techniques can be used to

obtain foams with rounded ultra-macroporosity. Freeze-casting, belonging to the sacrificial template

methods, can be used to obtain unidirectional anisotropic macropores, with the formation of unique

geopolymer lamellar porous structures (Fig.1). Lastly, the use of inert or partially reactive fillers results

in a further functionalization of the geopolymer, with effective production of highly macroporous

composites (as showed in Fig. 1 for the geopolymer-vermiculite composite).

The tailoring of the geopolymers porosity is of paramount importance for their potential application in

thermal insulation, filtration, catalysis, etc. Therefore, a deep characterization of the final materials, in

order to understand how the porosity may be developed or modified during the preparation, must be

performed combining different techniques, as N2 adsorption/desorption, Hg intrusion and µ-Computed

Tomography (µ-CT) (Fig.1).

Figure 1: examples of porous geopolymers and techniques to investigate the porosity.

Intrinsic

geopolymer

Sacrificial template – Freeze casting μ-Computed Tomography

Direct foaming – Si0 addition

Induced ultra-macroporosity Study of the porosity

Hg intrusion porosimetry

Addition of filler - vermiculite composite SEM microstructure



Importance of geopolymers for the valorization of various type of

contaminated waste

M. Soubrand 1, E. Joussein 1, S. Rossignol

1 Univ. Limoges, GRESE, EA 3040, 123 Avenue Albert Thomas, 87060 Limoges, France 2 SPCTS, UMR 7315, 12 Rue Atlantis, 87068 Limoges Cedex, France

In a context of contaminated mineral waste management (eg mining sediment, industrial by-

product such as phosphogypsum, slags, sewage-sludge…), the valorization way seems to be

interesting particularly in terms of geopolymers since these materials are increasingly used in

construction at the large scale or simply by inerting. In an economical point, the revaluation of

which are considered as final waste could be optimal if the valorization by geopolymerization

process uses only untreated waste. Moreover these types of waste are classically highly

contaminated in metallic elements which can induce environmental and sanitary risks. In this

way, it is quite important to (i) determine the feasibility of synthesize geopolymer from various

inorganic contaminated waste in substitution to metakaolin, (ii) understand the mechanisms

involved toward two silicate solution (Na and K), and to (iii) evaluate the change in the metallic

element speciation and leaching after geopolymerisation. The raw material as well as

consolidated material were characterized by X-ray diffraction, infrared spectroscopy, and

electron microscopy. The metallic element content was determined using ICP-OES/-MS and

chemical speciation by BCR investigations. The mechanical properties were evaluated and the

leaching behavior realized according to EN12-457 or TCLP. The results evidence the role of

geopolymer to incorporate wastes and stabilize the contaminants. However, the limit of waste

incorporation is by substitution is reactive dependent of waste material, the metakaolin and the

alkaline solution used. Finally, the metallic element bearing phases are mainly dissolved during

alkaline treatment and redistributed in the geopolymer matrix. The leaching experiments clearly

evidenced the possibility to stabilize the metallic element into geopolymer matrix.



Improving the clay bricks production: experimental clay mixtures and geopolymer

binders

Julie PEYNE1,2, Jérôme GAUTRON2, Julie DOUDEAU3, Emmanuel JOUSSEIN4, Sylvie

ROSSIGNOL1 1 SPCTS, CEC, 12 rue Atlantis, 87068 Limoges Cedex, France

2Bouyer Leroux, L’établère, 49280 La Séguinière, France 3Bouyer LerouxStructure, 31 route d’Auch 31170 Colomiers, France

4Université de Limoges, GRESE EA 4330, 123 avenue Albert Thomas, 87060 Limoges, France

As part of optimized energy consumption, clay brick is the ideal solution for the building construction

and eco performance buildings. Indeed, it is characterized by insulation properties, intrinsic to the raw

clay materials used, and by its ability to regulate interior temperature due to its high thermal inertia.

With a view of sustainable development, the goal "waste zero" in the brick clay process is to be achieved.

Thus, the production optimization requires understanding of various phenoma, such as the

manufacturing technique and the impact of raw materials on the production. Nonetheless, characterizatio

methods used currently in the brick production plan don't allow the distinction between clays materials. The aim of this work is to investigate and understand the role of raw materials on the production. This

study consists thus of the use of physic and chemical characterization techniques and of the use of several

raw clays materials used initially in the brick production. First, physical and chemical characterization of the clays were studied. Moreover, the mineralogy was

determined by X ray diffraction and FTIR spectroscopy. The firing behavior was investigated by DTA

measurments. Then, experimental clay mixtures were studied in order to obtain some abacus plots to

help in the brick production understanding. Next, the waste brick products were used in geopolymer

mixtures. Finally, the impact of some clay minerals was determined and it was showed that the waste

brick products are potential aluminosilicate materials for the geopolymer binders synthesis.



Study of the geopolymerization rate by thermal experiments

A. Autef1,2, E. Joussein3, G. Gasgnier2, S. Rossignol1 1 SPCTS, CEC, 12 rue Atlantis, 87068 Limoges Cedex, France

2IMERYS Ceramic Centre, rue soyouz, France 3Université de Limoges, GRESE EA 4330, 123 avenue Albert Thomas, 87060 Limoges, France

Geopolymers are amorphous three-dimensional aluminosilicate binders, which were

named in 1978 by J. Davidovits [i]. Geopolymeric materials may be obtained by a reaction of

an aluminosilicate source (industrial wastes, metakaolin, natural mineral or fly ash) with an

alkaline solution [ii] (generally potassium or sodium silicate) at room temperature. The silicate

solution used to activate aluminosilicate plays an important role in the lifecycle of geopolymers

[iii]. The alkaline silicate created by the dissolution of silica in a basic medium (water + KOH)

was chosen because of its high stability and low cost [iv]. Additionally, the use of quartz as a

substitute for amorphous silica reduces the cost of the final product. Increasing the amount of

amorphous silica in a mixture containing silica and quartz favors a polycondensation reaction

(i.e., geopolymerization) and improves the mechanical properties of the synthesized materials

[v]. The study aimed to investigate the polycondensation reaction during the consolidation step

of geopolymer formation and examine the various equilibriums at different temperatures. In

total, eleven compositions with various amounts of amorphous silica S (high reactivity) and

quartz Q (low reactivity) (from 100%Q to 100%S) were synthesized in basic media with

metakaolin. The synthesized samples were characterized by thermal analyses and mercury

porosimetry tests. Correlations between the loss of water and the molar ratio of each

composition were investigated.

The existence of four reactions during the consolidation process was evidenced (i) the

reorganization of the species, (ii) the dissolution of the metakaolin, (iii) the formation of

oligomers and (iv) the reaction of polycondensation. Moreover, two types of networks were

shown, a silicate solution network for quartz-rich samples and a geopolymeric network for

amorphous silica-rich samples. The nature of the primary network and the reactivity of the

synthesized sample depend on the reactivity of the silica source used.



Alkaline silicate solutions properties and their effect on sand agglomeration

and geopolymer formation

L. Vidal1, E. Joussein2, J-L. Gelet3, J. Absi4, S. Rossignol1

1 ENSCI, SPCTS, UMR 7315, 12 Rue Atlantis, 87068 Limoges Cedex, France 2 Univ. Limoges, GRESE, EA 3040, 123 Avenue Albert Thomas, 87060 Limoges, France

3 MERSEN, 15 Rue Jacques de Vaucanson, 69720 Saint-Bonnet-de-Mure, France 4 Univ. Limoges, SPCTS, UMR 7315, 12 Rue Atlantis, 87068 Limoges Cedex, France

Nowadays, one of the challenges set by companies is the production of materials with low energy

consumption. Governments also encourage this trend as part of environmental respect. This work is

focused on the electrical protection domain and particularly concerns the fuse technology. In this

context, the consolidation of agglomerated sand and geopolymer formation at low temperature with

alkaline silicate solution are proposed. The agglomeration of sand and the formation of geopolymers

imply to better understand the various properties and the interactions with alkaline solutions. For this

purpose, several silicate solutions with various Si/M molar ratios (M = Na or K) and different dilutions

were studied. To determine the behavior of these alkaline solutions, several parameters were studied

such as (i) pH values, (ii) the various silicates species present in the solution which depend on the Si/M

molar ratio, (iii) the effect of adjuvant such as ammonium molybdate, and finally (iv) the microwave

treatment. A correlation between the Si-O-Si peak position, the silicon concentration and the Si/M molar

ratio (M = Na or K) of the solutions was determined by infrared spectroscopy. This relation gives nice

information about the polymerization of the solutions. 29Si MAS NMR experiments of the various

alkaline solutions evidenced the influence of the addition of ammonium molybdate or microwave

treatment on the silicate species. Then, the interactions between alkaline silicate solutions and sand or

metakaolin were determined by measuring the wetting angle. Finally, the effect of different parameters

on the microstructure and mechanical properties of consolidated sand was determined thanks to

mechanical tests and scanning electron microscopy. All these characterizations will help to determine

the parameters permitting to obtain a fuse in one process step by geopolymer coating.



Re-use of waste glass in the preparation of geopolymer: as alternative

alkaline solution and solid precursor

Francisca Puertas1, Manuel Torres-Carrasco2

[email protected] / [email protected] 1,2Eduardo Torroja Institute for Construction Sciences (IETcc-CSIC)-Madrid, Spain

C/ Serrano Galvache 4, 28033

There is growing production of waste glass in the world, and even though this is a fully

recyclable material, the cost and environmental impact associated with its reprocessing makes it easier

and more economically viable, in many places, to landfill it. Therefore, there is an imminent need to

develop alternatives for re-utilisation of waste glass that can bring added value, so that this becomes

more viable than disposal.

Alkaline materials are characterised by how heat of hydration, high mechanical strength

and high resistance to aggressive chemical (acid or sulphate media and so on). In addition, their

manufacture is less energy intensive than Portland cement. These alkaline materials are strongest and

most durable when the activator used is waterglass, a family of synthetic alkaline silicate hydrate

solutions whose processing is costly (because is necessary around 1300 °C to produce it) and highly

polluting (CO2 emissions). One way of improving the economic and ecological balance of alkaline

cements would be to find substitute for these alkaline activators, for instance, with the re-use of urban

and industrial waste glass1-3. The chemical composition of urban and industrial waste glass, based

essentially on SiO2 and Na2O, makes these by-product potential members of the waterglass family of

alkaline activators.

Moreover, in order to maximise the utilisation of the waste glass, this study presents the

results of experiments aiming to produce geopolymers from waste glass, a non traditional material

compared to those usually found in the manufacture of geopolymers (such as blast furnace slag, fly ash

or metakaolin).

Although, waste glass could be used as source of silica and/or alkalis in fly ash, blast

furnace slag or metakalolin-based geopolymers, the study presented here concerns the use of waste glass

alone, activated by an alkaline solution (with alternative solution from the treatment of different waste

glasses). The objectives of this feasibility investigation were multiple:

1. To study the possibility to generate solutions of sodium silicates (as potential waterglass

solutions) by the solubility of different types of waste glass.

2. Formulate geopolymers based on waste glass: as partial replacement of blast furnace slag

binders or through the use of waste glass alone, activated by alkaline solutions.

REFERENCES: 1 M. Torres-Carrasco et al, Materiales de Construcción, 2014, 64, (314), e014 2 F. Puertas and M. Torres-Carrasco, Cement and Concrete Research, 2014, 57, 95-104 3 M. Torres-Carrasco and F. Puertas, Journal of Cleaner Production, 2015, 90, 397-408



Geopolymer incorporate silicate waste

Nicoletta TONIOLO (1), Aldo. R. BOCCACCINI (2)

Institute of Biomaterials, University of Erlangen-Nuremberg, Cauerstr. 6, 91058 Erlangen, Germany

Geopolymers were primarily developed for the construction industry as non-Portland cements due to

the fact that about 5-8% of the global CO2 emissions is generated from Portland production, it is in fact

estimate that for each ton of cement 1 ton of CO2 is generated. 1

A geopolymer is a product of an inorganic polymerization in which an aluminosilicate powder reacts

with an alkaline solution to achieve a chemical composition similar to natural zeolite material but with

an amorphous microstructure instead of a crystalline one. 2

With this new technology it is possible not only to reduce the cement industries CO2 emission, but also

to use waste materials that are currently not used in other industry but are abundant and urgent to dispose

of.

For this purpose in this work fly ash, a residues generated by coal combustion in the thermal power

plants in the east of Germany, was used as aluminosilicate source.

Samples using fly ash as aluminosilicate source material and activated by sodium silicate and sodium

hydroxide solution in different formulations were prepared and characterized. Their mechanical

resistance was assessed by a compressive test after 28 days, Fourier transform infrared spectroscopy

(FTIR) spectra were acquired, crystalline phases were detected by X-ray powder diffraction (XRD) and

finally the structural characterization, pore size and crack distribution were qualitatively evaluated with

scanning electron microscopy (SEM) Fig. 1.

Fig.1. Fly ash geopolymer surface

REFERENCES:

[1] Deschner F. Reaction of siliceous fly ash in blended Portland cement pastes and its effect on the chemistry of hydrate phases and pore solution. 2014:204.

[2] Davidovits J. Geopolymer chemistry and Applications. 3rd Edition.



Fly-ash/borosilicate glass based geopolymers G. Taveri1, I. Dlouhy1

1Institute of Physics of Materials (IPM), Zizkova 22, 61662 Brno, Czech Republic Geopolymers are promising as building and structural materials, nonetheless they still turn out to be too

expensive in comparison with Portland cements. One of ways how to improve the ratio between the

production costs and service properties is to produce geopolymer materials completely from waste

materials. Fly ash from fossil flue power plants has been proved to be a compelling source of alumino-

silicate species, glass powder from wastes, ensuring the right provision of silicate for the required in the

polycondensation process [1]. Moreover, the addition of borosilicates (glassware raw material) as waste

glass source can support the geopolymerization, since boron can act as aluminate inside the process. In

fact, boron oxide can assume a 4-fold coordination, and then participating in dissolution phase in a

tetrahedral configuration, such as [Al(OH)4]– and [SiO(OH)3]– or [SiO2(OH)2]2–

[2].

In this investigation, SEM observation has been carried out on the fly ash and on the final geopolymer

products. Instrumented indentation hardness, bending test and chevron notch flexural tests were carried

out in order to characterize mechanical properties and fracture resistance. Fracture toughness has been

evaluated by using the chevron notch technique, methodology described, e.g. in [4, 5]. The fracture

surfaces of the broken specimen were observed by SEM and confocal microscopy.

Table 1: Micro-indentation hardness values

Table 2:

Three points

bending test results - flexural

strength

Figure 1: Micro-indentation hardness

The results revealed a low flexural strength of the material (Table 2), Vickers hardness showed also

quite low values (fig.1 and Table 1). The fracture toughness values have been found to be about 0.3

MPam1/2 according to the methodology described in [4, 5].

Taking into account the first results, the crack resistance of the prepared material was very low. One of

possible ways how to increase both the crack resistance and bending strength is to produce geopolymer

material of composite type. The idea is based on the use the product of geopolymerization as a binder

for making composites materials, similar to those investigated in [3].

REFERENCES: [1] M. Torres-Carrasco, F. Puertas, Journal of Cleaner Production, 90(2015), 397-408.

[2] L. Weng, K. Sagoe-Crentsil, J Mater Sci, (2007) 42:2997–3006.

[3] T. Alomayri, F.U.A. Shaikh, I.M. Low, Composites: Part B, 50 (2013) 1–6.

[4] J.I. Bluhm, Eng Fract Mech, (1975), 7:593–604.

[5] A.R. Boccaccini, H. Kern, I. Dlouhy, Materials Science and Engineering A, 308, 1-2, 111-117, 2001.

Sample Fmax

N

hmin

µm

hmax

µm

HV 0.2

1 2.01 9.127 11.698 77.96

2 2.03 10.862 13.453 91.76 Sample Fmax

N

FlexStrength

MPa

1 5.56 4.73 2 2.98 5.29 3 3.26 4.13



Using lakhouat (NW Tunisia) mine tailing in metakaolin based geopolymers

J. Nouairi1, W. Hajjaji2,3, C. PATINHA2, E. SILVA2, F. Rocha2, M. Medhioub1 1 Dept of Geology, Faculty of Sciences of Sfax, 3018, Sfax-Tunisia

2 Geobiotec, Geosciences Dept, University of Aveiro, 3810-193 Aveiro. Portugal 3 Natural Water Treatment Laboratory, CERTE, BP 273, 8020 Soliman, Tunisia

Since the late 19th Century, the north of Tunisia, a major lead-zinc province, has seen intense mining

activity1. The open air stored tailings contain huge amounts of potentially toxic elements. Various

natural processes led to their transfer to surrounding soils and water pools2. One imminent case,

Lakhouat (North-western Tunisia) was a lead and zinc ore mine. Its exploitation lasted almost

a century (1892- 1992) and led to huge tailing deposits (600.000 tons)3. The primary aim of this

study is the characterization of Lakhouat tailings and their impacts on the environment by the

assessment of the PTE distribution. The mineralogical analysis showed the existence of pyrite

and galena, confirmed by DRX and SEM analysis.

To neutralize the negative impact of the contaminated mining discharges of Lakhouat, tailing

were used/introduced to produce geopolymers. New metakaolin based geopolymer formulations

were elaborated by addition of mining by-products thought sodium silicate/NaOH activation. The

influence on the microstructure and mechanical properties of compositional variation with partial

replacement of metakaolin by Zn-Pb rich rejects (10-20 %) and Si/Al ratio (2.5 and 3.5) were studied.

At initial stage (7 days curing), the combination of these two amorphous materials (metakaolin and

tailing) exhibited suitable compressive strength values (around 5 MPa).

Figure 1 mining village and tailing of Lakhouat

REFERENCES: 1 SAINFELD P. (1952)- Annales des mines et de la géologie numéro 9 les Gîtes plombozincifères de la Tunisie. Imprimerie S.E.F.A.N. Tunis. 252p. 2 Babbou-Abdelmalek C., SebeiA., and Chaabani A. (2011) - Incurred environmental risks and potential

contamination sources in an abandoned mine site. African Journal of Environmental Science and

Technology Vol. 5(11), pp. 894-915 3 ONM Internal report, 2006



Alkali activation of high calcium by-products and applications I. Papayianni 1, S. Konopisi 2, F. Kesikidou 3

1,2,3 Laboratory of Building Materials, Dept of Civil Engineering, Aristotle University of Thessaloniki (AUTH), Thessaloniki, Greece.

Corresponding author: E-mail: [email protected]

The main industrial by-products in Greece are calcareous fly ash coming from the combustion of lignite

power production in Northern Greece and ladle furnace slag resulting from the domestic metallurgical

industry. These by-products are produced in significant quantities, but eventually most of them are

discarded. The aim of this research is to study the utilization of high calcium by-products in the

production of cement-less building materials.

Figure 1 : Macroscopic images of (a) calcareous fly ash and (b) ladle furnace slag

The research concerns the study of the alkaline-activated pastes (specimen dimensions 25x25x100 mm)

of fly ash and ladle slag, after treating them with a basic alkali-metal silicate solution. Trial mixes of

these by-products were produced at different proportions (10, 20, 30 and 50%) and mechanical and

physicochemical characteristics were tested, in order to detect changes in structure.

Table 1 : Compressive strength of slag, S and fly ash, FA mixtures

Compressive strength, MPa

Mixture 7 days 28 days 90 days 180 days

SFA10 6.7 14.7 20.8 12.8

SFA20 7.3 13.0 22.9 15.1

SFA30 9.9 14.4 21.5 19.4

SFA50 13.7 23.6 32.9 23.3

Based on the test results, the research proceeded to the production of slabs (slab dimensions 200x200x25

mm) designed with recycled glass aggregates, so as to be benefited from the strength and the aesthetic

characteristics of alkali-activated mixtures of industrial by-products. Control tests were performed to

the slabs, such as flexural strength, impact strength, resistance to abrasion and water absorption of the

slabs, in order to check their suitability as wall covering tiles.

REFERENCES: 1 V. M. Malhotra, P. K. Mehta, High-Performance, High-Volume Fly Ash Concrete: Materials, Mixture

Proportioning, Properties, Construction Practice, and Case Histories, 2002, Marquardt Printing Ltd., Ottawa, Canada, Page(s): 14-17. 2 A. Palomo, M. W. Grutzeck, M. T. Blanco, Alkali-activated fly ashes, a cement for the future, Cem Concr Res, Vol. 29, No. 8, 1999, Page(s): 1323-1329. 3 I. Papayianni, S. Konopisi, K. Datsiou, F. Kesikidou, Products of alkali-activated calcareous fly ash and glass cullet, 2014, Int. J. Res. In Eng. And Technology 03 (13), 43-51. 4 J. L. Provis, J. S. J. van Deventer, Alkali-activated materials: State-of-the-Art Report, RILEM TC 224-AAM, 2014, Springer, ISSN 2213- 204X.

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