References of "Courard, Luc"
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See detailPatch repair: compatibility issues
Garbacz, Andrzej; Courard, Luc ULg; Bissonnette, Benoît et al

in Grantham, Michael; Basheer, Muhammed; Magee, Bryan (Eds.) et al Proceedings of the 5th International Conference on Concrete Repair (2014)

Repair of any concrete structure results in formation of complex, at least two-component repair systems. Compatibility approach is treated as a basic requirement during selection of repair material ... [more ▼]

Repair of any concrete structure results in formation of complex, at least two-component repair systems. Compatibility approach is treated as a basic requirement during selection of repair material. Recently, the understanding for compatibility requirements in repair systems approach is demonstrated in many papers. The aim of this paper is analyzing the compatibility between repair materials and concrete substrate in the case of patch repair. The compatibility issues were discussed in light of the various requirements which determine the mathematical space of loads, including chemical, mechanical and other physical (mainly thermal) loads. N-dimensional compatibility space is created, taking into account selected patch material control parameters. The requirements for good compatibility between repair material and concrete substrate can be formulated by using mathematical inequalities, where the variables are the material control parameters. The effects of properties of the both repair material and concrete substrate were analyzed using computer system ANCOMP developed at Warsaw University of Technology. Usability of this approach was demonstrated using selected case study as an example. [less ▲]

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See detailEtude de la durabilité des hydrofuges de surface pour la conservation du patrimoine en béton
Lucquiaud, Vincent ULg; Courard, Luc ULg

Poster (2014)

La protection du patrimoine historique en béton est un challenge pour les années futures. Un traitement hydrofuge retarde l’apparition de pathologies du béton et apporte une protection contre la ... [more ▼]

La protection du patrimoine historique en béton est un challenge pour les années futures. Un traitement hydrofuge retarde l’apparition de pathologies du béton et apporte une protection contre la pénétration de l’eau. Les produits existants - essentiellement du silane et siloxane base - ont été soumis à différents processus de vieillissement, tels que la carbonatation accélérée, des rayons UV, des cycles d'humidification, des chocs thermiques, et des cycles de gel-dégel. Leur efficacité a été évaluée suivant la mesure de l’angle de contact, leur perméabilité à la vapeur d’eau et aux chlorures et leur absorption capillaire. Les résultats de l’étude montre un bon comportement de ces produits aux les principaux vieillissements étudiés. [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 detailArgile, miscanthus et autres matériaux bio-sourcés
Grigoletto, Sophie ULg; Courard, Luc ULg

Scientific conference (2014)

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See detailDetection of near-field, low permittivity layers with Ground Penetrating Radar: analytical estimation of the reflection coefficient
Van der Wielen, Audrey; Courard, Luc ULg; Nguyen, Frédéric ULg

in LAMBOT, Sébastien (Ed.) Proceedings of 15th International Conference on ground Penetrating Radar (2014)

The reflection coefficient of GPR waves encountering embedded thin layers is commonly estimated using a plane wave, far field approximation. But when the thin layer is situated in the near field of the ... [more ▼]

The reflection coefficient of GPR waves encountering embedded thin layers is commonly estimated using a plane wave, far field approximation. But when the thin layer is situated in the near field of the antenna, the spherical nature of the waves and the possible propagation of a lateral wave into the layer may have a strong influence on the measured reflected amplitude. In this work, we studied through 2D FDTD simulations the behavior of a radar wave interacting with thin layers of different thicknesses. The snapshots and radargrams showed a large influence of the layer thickness on the wave propagation. For the very thin layers, the evanescent wave plays a major role and the plane wave approximation gives a good estimation of the reflection coefficient. For thicker layers, the specific inclination of each multiple reflection has to be taken into account, as well as the lateral wave propagation. On the basis of these observations, we determined which analytical method should be used for the analytical prediction of the reflection coefficient, as a function of the layer thickness. [less ▲]

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See detailDétermination des propriétés de couches minces dans le béton à l’aide d’un géoradar commercial à hautes fréquences: approche pic-à-pic et analyse fréquentielle du coefficient de réflexion
Van der Wielen, Audrey; Courard, Luc ULg; Nguyen, Frédéric ULg

in Balayssac, Jean-Paul (Ed.) Compte-rendus de Diagnobeton 2014 (2014)

The Ground Penetrating Radar (GPR) is an efficient tool for the non-destructive inspection of concrete structures. It is widely used for the detection of rebars or humid zones or for evaluating the ... [more ▼]

The Ground Penetrating Radar (GPR) is an efficient tool for the non-destructive inspection of concrete structures. It is widely used for the detection of rebars or humid zones or for evaluating the thickness of elements. But when an element contains a thin layer, the radar waves are submitted to multiple reflections on the interfaces and the layer appears in the radargram as a single reflection, whose detailed analysis can allow determining the thickness and the permittivity of the thin layer. Two approaches were considered in this paper. In the first one, the analysis is based on the peak-to-peak reflection amplitude. The second approach uses a frequency analysis of the reflection coefficient, whose amplitude and phase can then be calculated for several frequencies. With this method, the thickness and permittivity of the layer can in theory be simultaneously determined. Both methods were numerically validated through finite difference simulations and experimentally tested on concrete samples containing an air layer of variable thickness. We showed that the frequency analysis allowed to reach a higher precision in the parameters estimation for a limited additional computing cost. The method efficiency depends on the conditions and is optimal for layers with a high permittivity presenting a large contrast with the matrix. [less ▲]

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See detailNanocomposite fiber reinforced mortars
Coppola, Bartolomeo; Di Maio, Luciano; Courard, Luc ULg et al

in Proceedings of the International Conference on Composites/Nano Engineering (2014)

The use of fibers to reinforce a brittle material is an extensively studied application. In the field of cementitious materials a wide range of fibers have been investigated, from natural to synthetic ... [more ▼]

The use of fibers to reinforce a brittle material is an extensively studied application. In the field of cementitious materials a wide range of fibers have been investigated, from natural to synthetic fiber (wood, cellulose, carbon, glass, polypropylene) in order to achieve several purposes. Nowadays there is a continuing effort to take advantage of recent advances in nanotechnology, in the polymer and fiber industry. Nanoclays are some of the most affordable materials that have shown promising results in nanocomposite polymers. They are characterized by a “platelet” structure with average dimension of 1 nm thick and 70 to 150 nm wide. This work is aimed at studying the different behavior of fiber reinforced mortars, containing nanocomposite polymeric fibers. [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 detailNear-to-Surface properties affecting bond strength in concrete repair
Courard, Luc ULg; Piotrowski, Tomasz; Garbacz, Andrzej

in Cement and Concrete Composites (2014), 46

One of the main processes for repairing concrete structures is patch repair. Efficiency and durability of a repaired system depends on the bond between concrete substrate and repair material. By ... [more ▼]

One of the main processes for repairing concrete structures is patch repair. Efficiency and durability of a repaired system depends on the bond between concrete substrate and repair material. By increasing the surface roughness, the surface treatment of concrete substrate can promote mechanical interlocking that is one of the basic mechanisms of adhesion. Nevertheless, some problems may arise from “co-lateral” effects of the treatment, especially due to the development of microcracks inside the substrate. In the presented paper, the effect of concrete substrate surface preparation has been characterized by roughness measurement, description of microcracking in the near-to-surface layer and a pull-off cohesion test. After repair, pull-off bond strength has been evaluated. It is concluded that selection of a suitable surface treatment technique should be preceded by the analysis of its aggressiveness in relation to the concrete substrate strength. A procedure for bond strength estimation using multiple regression approach, based on parameters describing surface quality really generated from various roughening techniques, is then proposed. [less ▲]

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See detailRecycling and sustainable development
Courard, Luc ULg

Scientific conference (2013, December 17)

Conditions for developing recycling in good conditions (environmental, economical and social)

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See detailDe l’expérimentation à la modélisation des propriétés hygrothermiques de parois isolées en paille
Louis, Arnaud ULg; Evrard, Arnaud; Courard, Luc ULg et al

in Annales du Bâtiment et des Travaux Publics (2013)

Some results of aPROpaille project are presented. The goal of this project is to improve the knowledge about hygrothermal performances of walls in which thermal insulation is mainly provided by straw ... [more ▼]

Some results of aPROpaille project are presented. The goal of this project is to improve the knowledge about hygrothermal performances of walls in which thermal insulation is mainly provided by straw. Besides an overall characterization of straw properties and two types of earth plaster, a series of tests was performed to determine the hygrothermal properties of these materials: porosity, sorption curve, water vapour diffusion, capillary absorption, total water absorption, specific heat and thermal conductivity. The determination of these parameters required sometimes the implementation of unusual protocols or unreleased materials. Numerical simulations based on the properties defined in the test campaign are also presented. Results clearly point out the influence of the type of plaster and the orientation of fibres into straw bale. [less ▲]

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See detailDe l’expérimentation à la modélisation des propriétés hygrothermiques de parois isolées en paille
Louis, Arnaud ULg; Evrard, Arnaud; Biot, Benjamin et al

Conference (2013, May 31)

First results of aPROpaille project are presented. The goal of this project is to improve the knowledge about hygrothermal performances of walls in which thermal insulation is mainly provided by straw ... [more ▼]

First results of aPROpaille project are presented. The goal of this project is to improve the knowledge about hygrothermal performances of walls in which thermal insulation is mainly provided by straw. Besides an overall properties characterization of straw and two types of earth plaster, a series of tests was performed to determine the hygrothermal properties of these materials: porosity, sorption curve, water vapour diffusion, capillary absorption, total water absorption, specific heat and thermal conductivity. The determination of these parameters required sometimes the implementation of unusual protocols or unreleased materials. Numerical simulations based on the properties defined in the test campaign are also presented. Results clearly point out the influence of the type of plaster and the orientation of fibres into straw bale. [less ▲]

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See detailMatériaux et systèmes constructifs: critères de sélection
Courard, Luc ULg

Conference given outside the academic context (2013)

Donner quelques idées sur les raisons qui amènent l'ingénieur à baser son choix des matériaux sur des critères autres que techniques

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See detailDurabilité (s) des matériaux de construction : un challenge pour l’ingénieur
Courard, Luc ULg; Bissonnette, Benoît

Conference (2013, May 10)

Le choix des matériaux utilisés dans la construction repose sur des critères techniques identifiables et quantifiables tels la résistance mécanique, le comportement chimique ou le transfert de chaleur ... [more ▼]

Le choix des matériaux utilisés dans la construction repose sur des critères techniques identifiables et quantifiables tels la résistance mécanique, le comportement chimique ou le transfert de chaleur, paramètres qui permettent non seulement de satisfaire les exigences opérationnelles de l'ouvrage, mais aussi d'en garantir la durabilité et la durée de vie utile attendues. Quoi qu'il en soit, ces critères ne sont aujourd’hui plus suffisants: énergie grise, analyse de cycle de vie, incidence sur l’environnement, qualité environnementale des constructions, etc. sont de nouveaux facteurs qui interviennent dans le caractère « durable » des constructions. L’ingénieur se doit désormais d'intégrer ces considérations dans le dimensionnement et la réalisation des ouvrages, ce qui constitue un réel challenge pour l’avenir. [less ▲]

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See detailA surface engineering approach applicable to concrete repair engineering
Garbacz, Andrzej; Courard, Luc ULg; Bissonnette, Benoît

in Bulletin of the Polish Academy of Sciences. Technical Sciences (2013), 61(1), 73-84

The objective of the paper is to analyze the effect of surface roughness and superficial microcracking upon dhesion of repair systems using concrete surface engineering approach. The results presented in ... [more ▼]

The objective of the paper is to analyze the effect of surface roughness and superficial microcracking upon dhesion of repair systems using concrete surface engineering approach. The results presented in this paper have been obtained within the framework of research projetcs performed to develop a better understanding of factors affecting the adhesion of repair materials through a surface engineering approach. Based on the results of investigations, the authors showed that the durability and quality of concrete repairs depend to a large degree on the characteristics of the substrate. Mechanical preparation and profiling of the concrete surface to be repaired has to be balanced with potential co-lateral effects such as superficial cracking, too often induced as a result of inappropriate concrete removal method selection, and the loss of benefits due to better mechanical anchorage. The results obtained confirm also that Concrete Surface Engineering, as a scientific concept, will definitely contribute to shed more light on how to optimize repair bond, taking into account interactions between materials at different observation scales. [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 detailSurface properties of concrete and criteria for adhesion of repair systems
Courard, Luc ULg; Garbacz, Andrzej; Piotrowski, Tomasz et al

in Van Gemert, Dionys; Kabashi, Naser; Nushi, Violeta (Eds.) et al Proceedings of the 1st Symposium on Polymers in Concrete (2013)

Before any repair operation, an effective assessment of the concrete substrate has to be performed. Usually next to the surface reparation of concrete, evaluation of the cohesion of the superficial ... [more ▼]

Before any repair operation, an effective assessment of the concrete substrate has to be performed. Usually next to the surface reparation of concrete, evaluation of the cohesion of the superficial concrete is requested for adhesion and durability reasons. Many authors describe the influence of the surface preparation technique on the superficial cohesion of concrete or the adhesion. However, the real effects of surface preparation technique only begin to be investigated in terms of superficial microcracking or roughness quantification. This project was performed in regards to the influence of concrete substrate strength and preparation technique efficiency. The effect of the concrete removal/preparation technique is most likely dependent upon the nature and the quality of the concrete substrate. Preparation techniques are compared from the point of view of concrete removing but also potential deterioration. The visual observation of the concrete surfaces indicates that the high pressure water jetting technique induces a particular texture characterized by large waves mostly parallel to the water flow. The concrete slabs have afterwards been covered with a Self-Compacting Repair Mortar and adhesion has been characterized. [less ▲]

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See detailComparison of shear and pull-off tests for testing adhesion of different content limestone fillers mortars used as repair system
Chendes, Remus; Dan, Sorin; Courard, Luc ULg

in STOIAN, Valeriu; DAN, Daniel; BOB, Corneliu (Eds.) et al Construction sustainability: efficient solution for design, execution and rehabilitation of the building (2013)

When a repair operation is performed and a new concrete or mortar is applied on the old concrete substrate, it is very important to have a good bond between the old concrete layer and the repair concrete ... [more ▼]

When a repair operation is performed and a new concrete or mortar is applied on the old concrete substrate, it is very important to have a good bond between the old concrete layer and the repair concrete system. The bond strengths usually determinate using pure tensile tests (pull-off tests) because of the field applicability of this category of tests. However, in most of the applications, shear stress is the main reason of the bond failure. In general, bond strength under tensile is considered smaller than bond strength in shear stress conditions. The objective of this paper is to compare the results obtained from tensile and shear tests and to potentially determine a mathematical relation between shear and tension. The materials used for tests are Ordinary Portland Cement and modified limestone fillers mortars. Specific humidity storage conditions have been selected. [less ▲]

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See detailŚlad węglowy betonu
Załęgowski, Kamil; Jackiewicz-Rek, Wioletta; Garbacz, Andrzezj et al

in Materialy Budowlane (2013), 496

Different approaches of carbon foot print of concrete estimation were investigated. It was shown that value of CO2 emissions varies depending on accepted specificity of calculations. Special attention was ... [more ▼]

Different approaches of carbon foot print of concrete estimation were investigated. It was shown that value of CO2 emissions varies depending on accepted specificity of calculations. Special attention was focused on possibilities of production of concrete with decreased „carbon foot print”. Reduction of cement content by mineral additives replacement in concrete mixture as well as influence of aggregate type used, conditions of concrete transport and built in and CO2 sequestration via carbonation process du ring „pri ma ry and se cond li fe” of con - cre te we re al so ta ken in to con si de ra tion. [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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