References of "Michel, Frédéric"
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See detailMEASUREMENT OF MOISTURE DIFFUSIVITY BY INVESTIGATION OF SORPTION ISOTHERM AND MODELING MOISTURE TRANSFER OF MORTAR SUBMITED TO CONVECTIVE DRYING
Kahlerras, Loubna ULg; BELHAMRI, Azeddine; Fraikin, Laurent ULg et al

in Proceedings of The 20th International Drying Symposium (IDS 2016) (2016, August 08)

This work reports the results of experimental study concerning convective drying of cement mortar and the influence of water-to cement ratios (W/C) used for the preparation of mortar, on moisture changes ... [more ▼]

This work reports the results of experimental study concerning convective drying of cement mortar and the influence of water-to cement ratios (W/C) used for the preparation of mortar, on moisture changes. The first experimental campaign was a convective dryer; in the purpose to obtain the drying curves of mortar and the influence of water to cement ratios (W/C) on drying kinetics. A second experimental campaign aims to characterize from textural and hydric point of view, the materials, by mean of DVS (dynamic vapor sorption) In order to obtain sorption cycles and identify the moisture diffusivity coefficient of mortar. The pore size distribution is obtained from sorption cycles and completed by MIP. The contribution of each components of the microstructure to the diffusion is studied. Finally X-ray microtomography is used to measuring the moisture content in the internal structure of mortars during drying. [less ▲]

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See detailCiments ternaires à haute teneur en calcaire
Pierre, Christian; VanHamme, Géraldine; Lauch, Kim-Séang et al

Report (2016)

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See detailInfluence de la fraction granulaire et de l'origine des granulats recyclés sur leurs propriétés
Zhao, Zengfeng ULg; Courard, Luc ULg; Michel, Frédéric ULg et al

in Courard, Luc; Collin, Frédéric; Cerfontaine, Benjamin (Eds.) RUGC 2016 (2016)

De très grandes quantités de déchets de construction et de démolition sont produites chaque année. Afin de faire bon usage des granulats recyclés (GR) dans le béton, il est très important d’étudier ... [more ▼]

De très grandes quantités de déchets de construction et de démolition sont produites chaque année. Afin de faire bon usage des granulats recyclés (GR) dans le béton, il est très important d’étudier l’influence de la fraction granulaire et de l’origine des granulats recyclés sur leurs propriétés. Dans cette étude, les granulats recyclés de blocs (GR_Blocs) et de hourdis (GR_Hourdis) ont été concassés et puis séparés en 4 fractions granulaires (0/2, 2/6,3, 6,3/14, 14/20mm). Chaque fraction granulaire des GR a été caractérisée. Les résultats montrent que la teneur en pâte de ciment durcie des GR augmente lorsque la taille des particules diminue. Les sables recyclés possèdent ainsi des teneurs en pâte de ciment nettement plus élevées que les gravillons recyclés. Les sables recyclés possèdent en particulier un coefficient d’absorption d’eau très élevé par rapport aux gravillons recyclés. Les valeurs de teneur en pâte de ciment durcie obtenues pour les GR_Blocs sont plus faibles que celles mesurées sur les GR_Hourdis, ce qui provient d’une plus faible quantité de pâte de ciment initiale du bloc. Les résultats montrent que pour toutes les fractions des GR, les GR_Hourdis sont plus anguleux que les GR_Blocs. [less ▲]

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See detailImproving properties of recycled concrete aggregates by accelerated carbonation
Zhao, Zengfeng ULg; Remond, Sébastien; Damidot, Denis et al

in Proceedings of the 4th International Conference on Sustainability Construction Materials and Technologies (2016)

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See detailResearch Self-Evaluation Report of the Department ArGEnCo
Collin, Frédéric ULg; Dewals, Benjamin ULg; Elsen, Catherine ULg et al

Report (2015)

Evaluation is nowadays a general trend in the European Universities. At the University of Liège, the evaluation process is threefold: fist there is the evaluation of the bachelor and master degrees, then ... [more ▼]

Evaluation is nowadays a general trend in the European Universities. At the University of Liège, the evaluation process is threefold: fist there is the evaluation of the bachelor and master degrees, then the second evaluation concerns the internal administrations and finally Research activities are being evaluated. This quality policy at the different levels of the Institution is organized by the Vice-Rector for Quality, Pr. Freddy Coignoul and the SMAQ service (Service de Management et d’Accompagnement à la Qualité), which aims to promote, coordinate and disseminate within the University of Liège a culture of the Quality, founded on the values of the Institution. The Research assessment is a procedure undertaken by the University in order to promote the quality of the research in the Departments or research centres. Within the Faculty of Applied Sciences, the evaluation of the Bachelor and Master degrees in Engineering was carried out in 2013 by the AEQES (Agence pour l’Evaluation de la Qualité de l’Enseignement) and CTI (Commission des Titres d’Ingénieur - France). The present report is dedicated to the evaluation of research led in the Education and Research Department (DER) ArGEnCo. The present evaluation report proposes a global presentation of all our research activities. At the Department level, one of the elected members of the Executive Bureau is in charge of the Research, covering both evaluation and quality policy. In October 2013, the Executive bureau appointed a research steering committee, whose fist task was to coordinate the present evaluation report, following the guidelines of the SMAQ service. The draft of such a document arises from the work of the steering committee but also from the contributions of all Department members, who were asked to contribute to the report or to complete databases. The progress of this evaluation report was presented by the Steering committee to the Department Council and during the General Assembly of the Department. Moreover, two Focus groups were organized by the SMAQ service, in order to get the feedback of technician and administrative members on one hand and scientific members on the other hand, on the general organization of the research in the ArGEnCo Department. The reports of these two Focus groups (Appendix 4 in French) underpinned our thinking about our research management. This report is therefore the fist evaluation of the research led in the Department, the present effort should be pursued, and deepened, within the coming years. Some of the databases necessary for the evaluation have been developed in the frame of this procedure. This has resulted in a huge amount of work for every Department members to collect all the data. New procedures in the management of the Department will help establishing the next research evaluation reports systematically, in particular for the collection of the complete dataset. Following the guidelines of the SMAQ service, this evaluation report is divided into two main parts: the fist one focuses on a self-evaluation report of the research activities and the second part presents the Action Plan of the Department for the next five years to come. The self-evaluation report is composed of four Sections: Section one presents the Research organization and topics of the Department, Section two focuses on the Research activities, Section three gives an overview of the mobility (in and out), the attractiveness and the scientific recognition of the Department and finally Section four is dedicated to the resources available in ArGEnCo Department. Each Section ends up with a SWOT analysis. The Action Plan proposed by the Steering Committee results from the analysis of the self-evaluation report, insofar as it synthesizes and prioritizes the actions of the Department for the next fie years. These priorities are formulated as proposals following a contractual approach between research entities and Institution authorities, to whom the report will be presented. [less ▲]

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See detailCarbonated concrete blocks for CO2 captation
Courard, Luc ULg; Parmentier, Véronique; Michel, Frédéric ULg

in Materialy Budowlane (2015), 10

The CO2 captation process called carbonation, improves specific properties of the concrete during the conversion of carbon dioxide CO2 into calcium carbonate CaCO3. Current environmental concerns motivate ... [more ▼]

The CO2 captation process called carbonation, improves specific properties of the concrete during the conversion of carbon dioxide CO2 into calcium carbonate CaCO3. Current environmental concerns motivate the study of carbonation in order to maximize the absorption of carbon dioxide. Moreover, lightweight concrete with bio-based products knows an interesting development in the construction field, especially as thermal insulation panels for walls in buildings. Concrete blocks produced with miscanthus mineralized aggregates offer interesting mechanical properties and minimal environmental impact. [less ▲]

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See detailStudy of water diffusivity during drying of mortar
Kahlerras, Loubna ULg; Courard, Luc ULg; Michel, Frédéric ULg et al

in Proceedings of the 5th European Drying Conference (EuroDrying'2015) (2015)

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See detailEvaluation of the durability of hydrophobic treatments on concrete architectural heritage
Lucquiaud, Vincent ULg; Courard, Luc ULg; Gérard, Olivier et al

in Restoration of Buildings and Monuments = Bauinstandsetzen und Baudenkmalpflege (2014), 20(6), 395404

The protection of historical concrete structures is a challenge for the coming years. Hydrophobic treatment may reduce the deterioration process while providing protection against water penetration ... [more ▼]

The protection of historical concrete structures is a challenge for the coming years. Hydrophobic treatment may reduce the deterioration process while providing protection against water penetration. Existing commercial products —mainly silane or siloxane in either water or solvent based formulations– were submitted to different ageing processes including UV radiation, dry-wet cycles, thermal shocks, freeze-thaw cycles, carbonation and their effectiveness has been evaluated on the basis of contact angle, vapour and chloride permeability and, capillarity water absorption. The results obtained clearly show that hydrophobic treatments display a good behaviour under the main ageing conditions. [less ▲]

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See detailExperimental study of the drying kinetic of mortar
Kahlerras, Loubna ULg; Michel, Frédéric ULg; Courard, Luc ULg et al

Poster (2014, August 24)

This work reports the results of an experimental study concerning on one hand the influence of water-to cement ratios (W/C), and the role of aggregates on the other hand on the drying kinetics of cement ... [more ▼]

This work reports the results of an experimental study concerning on one hand the influence of water-to cement ratios (W/C), and the role of aggregates on the other hand on the drying kinetics of cement pastes during thermal drying. Three types of cement pastes were realized and studied; cement pastes with ratios W/C 0.4, W/C 0.5 and mortar with ratio W/C 0.5. These tries present the advantage to reproduce the natural conditions met in the problems of interaction atmosphere and material. Cylindrical samples of cement of size (17 X 13) mm are dried in a convective dryer. The sample is continuously weighed during the drying test and its mass is recorded every 60 s, in the purpose to obtain the drying curves. The results show that the increase of the W/C ratio leads to an increase of the drying rate due to the increase of the initial porosity. The effect of the introduction of aggregates is observable by the comparison of the drying curve obtained for the mortar and the cement pastes. The results show a decrease of the drying kinetics with mortars. The results also show that the air drying temperature has a large impact on the drying process, increasing the temperature leading to significant drying time reduction. The Effective diffusion coefficient is calculated by comparison between the experimental results and the analytical solution of Fick’s equation written for a finite medium. [less ▲]

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See detailLimestone fillers cement-based composites: effects of blast furnace slags on fresh and hardened properties
Courard, Luc ULg; Michel, Frédéric ULg

in Construction and Building Materials (2014), 51

Limestone filler is a raw material that is already used in several applications like paints, bricks, bituminous mixtures…etc. Moreover, and particularly in Belgium, classical additions for concrete like ... [more ▼]

Limestone filler is a raw material that is already used in several applications like paints, bricks, bituminous mixtures…etc. Moreover, and particularly in Belgium, classical additions for concrete like fly ashes and granulated blast furnace slags are becoming rare; there is a need for new additions that could have a positive effect on the properties of the fresh and hardened cementitous composites. Substitution of limestone filler in Portland cement and Granulated blast furnace slag cement has been realized between 15 and 27 % in mass. In addition to the characterization of the powder itself – specific mass, specific surface and laser granulometry – the problem of the water demand has been analysed: it seems that it remains constant with the substitution rate. Electric conductivity has also been performed in order to study the evolution of the “dormant” period. Tests on hardened mortars were performed with regard to mechanical properties and evolution of the porosity. Test results indicate that the porosity seems to be finer in the case of granulated blast furnace slags cements, partially due to a very low diameter of the slags particles. Oxygen permeability doesn’t seem to be influenced by the filler while capillary absorption increases with substitution rate. Finally, carbonation rate, sulphate resistance and chloride penetration show quite interesting behaviours, leading to the conclusion that limestone fillers maybe a good substitution material. [less ▲]

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See detailEffects of limestone fillers on surface free energy and electrical conductivity of the interstitial solution of cement mixes
Courard, Luc ULg; Michel, Frédéric ULg; Perkowicz, Sylwia et al

in Cement and Concrete Composites (2014), 45

Most of concrete formulations actually contain mineral additives that are used as an inert filler or supplementary cementitious material (as type II addition). These materials are generally used in order ... [more ▼]

Most of concrete formulations actually contain mineral additives that are used as an inert filler or supplementary cementitious material (as type II addition). These materials are generally used in order to increase concrete performances both in its fresh and hardened states. The mineral additives usually improve the consistency and workability of fresh concrete and reduce the water demand for a required concrete slump because of an additional volume of fines. The way of action depends on the physical and chemical characteristics of fillers. The study of surface free energies and electric conductivities of interstitial solutions of cement mixes modified by blast furnace slags and limestone fillers contributes to a better knowledge of hardening and interaction process. [less ▲]

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See detailDurability of hydrophobic treatments on concrete monuments
Courard, Luc ULg; Lucquiaud, Vincent ULg; Gérard, Olivier et al

in Proceedings of 7th International Conference on Water Repellent Treatment and Protective Surface Technology for Building Materials (2014)

The protection of concrete historical structures is a challenge for the coming years. Hydrophobic treatment may induce a delay in degradations progress as well as a protection against water penetration ... [more ▼]

The protection of concrete historical structures is a challenge for the coming years. Hydrophobic treatment may induce a delay in degradations progress as well as a protection against water penetration. Existing products - mainly silane and siloxane based – have been submitted to different ageing processes including UV radiation, moistening cycles, thermal shocks, freeze-thaw cycles, carbonation and efficiency has been evaluated on the base of contact angle, vapour and chloride permeability and, capillarity absorption. Investigation results clearly show a good behaviour of hydrophobic treatments under main ageing conditions. [less ▲]

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See detailParticle size distribution of limestone fillers: granulometry and specific surface area investigations
Courard, Luc ULg; Michel, Frédéric ULg

in Particulate Science and Technology (2014), 32(4),

Mineral fillers can be defined as “inert materials included in a mix design for some useful purpose”. They can be added to compounds in order to complete a large variety of final properties without ... [more ▼]

Mineral fillers can be defined as “inert materials included in a mix design for some useful purpose”. They can be added to compounds in order to complete a large variety of final properties without increasing costs or to improve specific characteristics like hardness, brittleness, impact strength, compressive strength, softening point, fire resistance, surface texture, electrical conductivity, …etc. In Belgium, locally available limestone fillers are specifically very well-adapted for the optimisation of particle packing and flow behaviour of cementitious pastes in concrete mixes. Limestone fillers may be easily characterized in terms of chemical and mineralogical properties. These properties are fundamental for the study of the behaviour of concrete mixes in fresh state and for understanding interactions existing at the level of the Interfacial Transition Zone between aggregates and cement paste. These properties are however insufficiently discriminant and particle size, as well as shape distribution, seem to have a potential influence on physical phenomena which happen during the setting process. The aim of this paper is to compare five major techniques used to quantify the size and the shape of limestone fillers particles: laser diffraction scattering, wet sieving and image analysis for particle size measurement and BET adsorption and Blaine permeability methods for specific surface area. [less ▲]

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See detailInfluence of particle shape on size distribution measurements by 3D and 2D image analyses and laser diffraction
Califice, Arnaud ULg; Michel, Frédéric ULg; Dislaire, Godefroid ULg et al

in Powder Technology (2013), 237

This paper highlights the fact that particle size distribution (PSD) is not unique for the same product, and is dependent on the chosen measurement technique, especially for asymmetric shapes. Laser ... [more ▼]

This paper highlights the fact that particle size distribution (PSD) is not unique for the same product, and is dependent on the chosen measurement technique, especially for asymmetric shapes. Laser diffraction and 2D image analysis are commonly used PSD measurement techniques. However, the resultsmay not be representative of the true physical dimensions of the particles. The influence of particle shape on PSD results obtained from 2D/3D image analysis and laser diffraction was investigated. Two metallic powders presenting extreme shape properties (round and elongated particles) were analyzed, as well as a blend of the two pure products. 2D image analysis and laser diffraction results were compared to 3D image analysis (measuring the true particle size). This paper compares the PSD results obtained from the three methods. Some commonly used size parameters in image analysis software did not give meaningful results in regard of the true physical dimensions of the particles. The existence of the two populations (products with extremely different shape and size characteristics) could not be identified with such size parameters, and laser diffraction also performed poorly. The PSD obtained from more precise size parameters (image analysis) better corresponded to the true dimensions of the particles. This study highlights the strengths and weaknesses of particle size analysis techniques when studying products presenting diverse particle shapes, and points out that caution is required in the choice of the size parameters, and in the interpretation of PSD results. [less ▲]

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See detailDetermination of Moisture Diffusivity During Drying of Mortar Cement: Experimental and Modeling Study
Bennamoun, Lyes ULg; Kahlerras, Loubna ULg; Michel, Frédéric ULg et al

in International Journal of Energy Engineering (2013), 3(1), 1-6

The aim of this study is the experimental characterization of the behaviour of a mortar during convective drying. We focalise on mortar that has a rate water-cement of 0.5. The drying tests are developed ... [more ▼]

The aim of this study is the experimental characterization of the behaviour of a mortar during convective drying. We focalise on mortar that has a rate water-cement of 0.5. The drying tests are developed in a micro-convective dryer that can use samples weighing from 0 to 8g. The advantage of these experiments is to reproduce the natural conditions that can be found during the treatment of the mortar-atmosphere problems. The response of the drying curve or the drying kinetic depends on the applied drying conditions. So, the temperature of the air varies from 60°C to 130°C, the velocity of the air is changed from 2 m.s-1 to 5 m. s-1and the relative humidity is kept less than 1.7%. The comparison between the experimental results and the proposed analytical solutions of the equation of diffusion represented by Fick’s law, applied for a finite shape, allows determination of the values of the diffusion coefficient. It has a value of 1.71×10-10 m2.s-1 at 60°C, 13.69×10-10 m2.s-1 at 90°C and 16.27×10-10 m2.s-1 at 130°C. Calculation of the activation energy and the D0 constant are also possible. [less ▲]

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See detailFixation du CO2 dans les blocs de béton à base de granulats recyclés
Parmentier, Véronique; Michel, Frédéric ULg; Courard, Luc ULg

in Gagné, Richard (Ed.) Actes de la 14ème édition des Journées Scientifiques (2013)

A l’heure où l’industrie cimentière est majoritairement responsable de la production de CO2 dans le secteur de la construction, il s’avère utile de compenser cette production par un phénomène inverse: la ... [more ▼]

A l’heure où l’industrie cimentière est majoritairement responsable de la production de CO2 dans le secteur de la construction, il s’avère utile de compenser cette production par un phénomène inverse: la captation du CO2. Ce processus d’absorption de CO2, appelé carbonatation, améliore certaines propriétés du béton lors de la conversion du dioxyde de carbone CO2 en carbonate de calcium CaCO3. Les préoccupations environnementales actuelles motivent l’étude de la carbonatation dans le but de maximiser l'absorption du dioxyde de carbone. Les granulats recyclés, produits à base de déchets de béton concassés mécaniquement, peuvent prendre place dans de nouvelles applications en béton. Ils peuvent remplacer les granulats naturels en tout ou en partie, épargnant ainsi l’extraction des matières premières naturelles. La combinaison des deux approches vise à élaborer un produit dont l’impact environnemental est réduit au minimum. [less ▲]

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See detailUse of contaminated recycled aggregates for concrete design: properties and durability
Courard, Luc ULg; Michel, Frédéric ULg; Debieb, Farid

in Zajc, Andrej (Ed.) Doseganje posebnih lastnosti betonov z uporabo odpadlih materialov (2012, May 23)

Construction waste management is a quite important economic and environmental deal for our societies. More than 2 million tons demolition and construction wastes are annually produced only in Wallonia ... [more ▼]

Construction waste management is a quite important economic and environmental deal for our societies. More than 2 million tons demolition and construction wastes are annually produced only in Wallonia, Southern Region of Belgium; recycling has clearly to be promoted. Roller Compacted Concrete (RCC) is a special dry concrete made of aggregates, water and low quantity of cement, laid down and compacted like a soil, for the construction of massive structures like dams or large horizontal surfaces like road foundations. Replacement of natural aggregates by concrete road recycled aggregates in the mix design of concrete is a solution to decrease nature depletion. Natural concrete slabs were cured in water, sea water, chloride solutions or sulphate solutions and then crushed to obtain virgin and contaminated (polluted) recycled aggregates. The aim of this research is the total replacement (100% coarse and fine) of natural aggregates (NA) by recycled concrete aggregates (RA) in the composition of a roller compacted concrete. The natural and recycled aggregates are characterised and compared. The mechanical properties and durability performances of concrete with contaminated RA are analysed. The experimental results showed that the polluted RA are much richer in chlorides than in sulphates and are leached if they are soaked in water. Significant differences were observed between the properties of original and new concrete and the results demonstrated the need of taking these contaminations into account. [less ▲]

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See detailSupplementary Cementitious Materials for Concrete: Characterization Needs
Juenger, Maria; Provis, John L.; Elsen, Jan et al

in Proceedings of the XXI International Materials Research (2012)

A wide variety of materials are currently used as supplementary cementitious materials (SCMs) for concrete, including natural materials and byproducts from various industries. Historically, natural SCMs ... [more ▼]

A wide variety of materials are currently used as supplementary cementitious materials (SCMs) for concrete, including natural materials and byproducts from various industries. Historically, natural SCMs, mostly derived from volcanic deposits, were common in concrete. In recent years, the dominant SCMs have been industrial by-products such as fly ash, ground granulated blast furnace slag (GGBFS), and silica fume. There is currently a resurgence of research into historic and natural SCMs, as well as other alternative SCMs for many reasons. The primary benefits of SCM use in improvement of long-term mechanical performance, durability, and sustainability are widely accepted, so local demand for these materials can exceed supply. This paper describes some of the SCMs that are attracting attention in the global research community and the properties and characteristics of these materials that affect their performance. Special attention is paid to the importance and demands of material characterization. Many SCMs do not necessarily lend themselves to characterization methods used in standardized test methods, which sometimes fail to describe the properties that are most important in predicting reactivity. [less ▲]

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See detailEffet de l’empilement et de la forme des additions sur les propriétés des liants à matrice cimentaire
He, Huan; Courard, Luc ULg; Michel, Frédéric ULg et al

in Georgin, Jean-François (Ed.) Recueil des communications des journées scientifiques du (RF)²B (2012)

Mélanger le ciment avec des additions minérales, en particulier avec des sous-produits industriels, permet de réduire efficacement la consommation de ciment et de réduire son impact environnemental ... [more ▼]

Mélanger le ciment avec des additions minérales, en particulier avec des sous-produits industriels, permet de réduire efficacement la consommation de ciment et de réduire son impact environnemental. Récemment, un concept novateur a été proposé en vue de remplacer les plus gros grains de ciment par les charges inertes, en vue du développement d’un ciment durable. En tant que mécanisme de base, l’empilement des particules joue un rôle important dans le remplacement ou le mélange. Dans la première partie de l'étude, l’empilement des grains de ciment, de filler calcaire (LF) et de ciment mélangé est abordé. Une nouvelle méthode, basée sur l’empilement en phase humide, est comparée à une méthode d'empilement à sec. La distribution de taille des particules (PSD) et la forme des particules des différentes poudres sont caractérisées sur base d’un système d'analyse d'image avancée. Le document présente les résultats des tests d’empilement avec l’influence du paramètre PSD, de la forme des particules, du type de ciment, de l’énergie de vibration, du mélange et du superplastifiant (Sp). Les avantages et les limites des deux méthodes sont également discutés. [less ▲]

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