References of "Courard, Luc"
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See detailUtilisation du béton recyclé dans la formulation des bétons auto-compactants
Bouarroudj, Mohamed Elkarim ULg; Colman, Charlotte ULg; Robinet, Eva ULg et al

Scientific conference (2017, July 06)

Notre travail porte sur l'étude du comportement des bétons auto-compactants ou auto-plaçants réalisés à base de sable recyclé et de sable recyclé broyé. La première étape consiste en une caractérisation ... [more ▼]

Notre travail porte sur l'étude du comportement des bétons auto-compactants ou auto-plaçants réalisés à base de sable recyclé et de sable recyclé broyé. La première étape consiste en une caractérisation physico-chimique et minéralogique (masse volumique, absorption d’eau, teneur en sulfates, composition chimique...) d’un sable de béton recyclé. Dans un deuxième temps, une étude des propriétés rhéologiques et mécaniques est réalisée sur des mortiers afin de réduire la quantité de matériaux naturels utilisés. La composition du mortier de base est dérivée d’une formulation type de béton auto-compactant préalablement vérifié sur la base de différents critères classiques (étalement au cône, t500, teneur en air,…). Notre étude s’intéresse d’une part aux impacts de la substitution du filler calcaire par du sable recyclé broyé (série 1) et d’autre part aux impacts de la substitution du sable naturel par du sable recyclé (série 2). [less ▲]

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See detailInfluence of granular fraction and origin of recycled concrete aggregates on their properties
Zhao, Zengfeng ULg; Courard, Luc ULg; Michel, Frédéric ULg et al

in European Journal of Environmental and Civil Engineering (2017)

Large quantities of construction and demolition wastes are produced each year. In order to make good use of recycled concrete aggregates (RCA) in concrete, it is very important to study the influence of ... [more ▼]

Large quantities of construction and demolition wastes are produced each year. In order to make good use of recycled concrete aggregates (RCA) in concrete, it is very important to study the influence of the granular fraction and the origin of RCA on their properties. In this study, RCA from industrial produced blocks (RCA_Blocks) and slabs (RCA_Slabs) were crushed and then separated into four granular fractions (0/2, 2/6.3, 6.3/14, 14/20 mm). Each granular fraction of RCA was physically characterised. Real RCA from recycling plant were also used for comparison. The results showed that recycled sands offered significantly higher cement paste content (higher bound water content) than coarse recycled aggregates. The fine RCA had therefore a higher water absorption coefficient compared to coarser fractions of RCA. The water absorption of finer fraction of RCA could be extrapolated precisely from the relationship between water absorption and cement paste content (or bound water content) of three coarse fractions of RCA. The values of hardened cement paste content obtained for the RCA_Blocks were lower than those measured on the RCA_Slabs, which was due to a smaller amount of initial cement paste content in blocks. The results showed that RCA_Slabs were more angular than RCA_Blocks. [less ▲]

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See detailDevelopment of Specifications and Performance Criteria for Surface Preparation Based on Issues Related to Bond Strength
Bissonnette, Benoît; Courard, Luc ULg; Garbacz, Andrzej et al

Report (2017)

In addition to the development of a satisfactory test procedure and recommendations to improve the overall quality of concrete repair works, the authors of this proposal intend to collaborate with various ... [more ▼]

In addition to the development of a satisfactory test procedure and recommendations to improve the overall quality of concrete repair works, the authors of this proposal intend to collaborate with various representatives from public agencies and from the industry to facilitate technological transfer. Presentations will be made in conferences and workshops in North America and Europe. At the end of the project, the results shall include two MSc theses and at least two papers in major journals, such as Concrete International or ACI Materials Journal. Also, the project should provide the basis towards a standard procedure for the evaluation of superficial cohesion of concrete, in relation with surface preparation and concrete removal techniques. Finally, recommendations and specifications could be incorporated in future versions of the ACI-ICRI Manual of Concrete Repairs as well as in DOT’s specifications. [less ▲]

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See detailAdhérence des réparations en béton: concepts, facteurs d'influence et évaluation
Bissonnette, Benoît; Courard, Luc ULg; Garbacz, Andrzej

Scientific conference (2017, February 20)

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See detailMesure de l'adhérence et principaux paramètres d'influence
Bissonnette, Benoît; Courard, Luc ULg; Garbacz, ANdrzej

Scientific conference (2017, February 20)

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See detailNotions de compatibilité relatives au développement de l'adhérence
Courard, Luc ULg; Garbacz, Andrzej; Bissonnette, Benoît

Scientific conference (2017, February 20)

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See detailSurface characterization methods for quality control of repair
Garbacz, Andrzej; Bissonnette, Benoît; Courard, Luc ULg

Scientific conference (2017, February 20)

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See detailAn investigation on the use of coarse volcanic scoria as sand in Portland cement mortar
Juimo Tchamdjou, Willy Hermann; Grigoletto, Sophie ULg; Michel, Frédéric ULg et al

in Case studies in Building Materials (2017), 7

In this study, the utilization of coarse volcanic scoria CVS as sand in Portland cement mortar was investigated. The aim of this study is to give some physical properties, mechanical properties and ... [more ▼]

In this study, the utilization of coarse volcanic scoria CVS as sand in Portland cement mortar was investigated. The aim of this study is to give some physical properties, mechanical properties and durability properties of CVS mortars investigated at short term of curing in comparison with a reference mortar. Investigation was carried out on three groups of mortar samples according to the proportion of fine particles on the coarse volcanic scoria, “low” for the first group MCVS1, “average” for the second group MCVS2 and “high” for the third group MCVS3. The reference mortar has been made with standard sand. The water–cement w/c ratio and sand/cement s/c ratio used in the mixtures were 0.5 and 3, respectively according to European Standard EN 196-1- 2005. The particle size of CVS aggregates used to prepare mortar mixtures were between 0.08 mm and 2.00 mm like in the standard sand. Compressive and flexural strengths were tested at mortar age of 28 days. The results revealed improved compressive and flexural strengths, which were maximal for the MCVS3 samples. Unit weight increased with the ratio of fine CVS size between 0.08–1.00 mm. Sorptivity and carbonation depth decrease as the ratio of fine CVS increase. Based on these results, using Cameroonian volcanic scoria in the appropriate particles size ratio composition will improve these mortar characteristics. CVS mortars can be used for more applications for building construction in Cameroon and all over the world, especially in regions where volcanic scoria resources are abundant. [less ▲]

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See detailSpecification guidelines for surface preparation of concrete prior to repair
Courard, Luc ULg; Bissonnette, Benoît; Garbacz, Andrzej

in High Tech Concrete: Where Technology and Engineering Meet (2017)

The repair of concrete requests specific preparation operations needed for guaranteeing compatibility between substrate and new materials as well as the development of adhesion properties. These ... [more ▼]

The repair of concrete requests specific preparation operations needed for guaranteeing compatibility between substrate and new materials as well as the development of adhesion properties. These specification guidelines contain design and construction recommendations for surface preparation of concrete for repair and overlay. The paper summarizes current knowledge, best practices and results of the research concerning the surface preparation of concrete prior to application of repair/overlay materials. The specifications are applicable to repairing damaged or deteriorated concrete structures, correcting design or construction deficiencies, or upgrading a structure for new uses, or to meet more restrictive code requirements. This is based on 10 years research activities on this topic through scientific cooperation programs between Wallonia, Quebec and Poland and support of American Concrete Institute. [less ▲]

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See detailInfluence of hydrophobic treatments applications on the concrete carbonation delay
Courard, Luc ULg

in De Schutter, Geert (Ed.) Proceedings RILEM PRO 107 (2017)

Water-repellents are increasingly used in the recent years. Those ones are generally used to reduce the degradation caused by freeze / thaw, by alkali-aggregates reaction or by chloride ions. The ... [more ▼]

Water-repellents are increasingly used in the recent years. Those ones are generally used to reduce the degradation caused by freeze / thaw, by alkali-aggregates reaction or by chloride ions. The objective of this study is to determine if hydrophobic treatments also have an influence on the propagation of the carbonation front into the concrete. Capillary absorption tests, permeability to water-vapor and oxygen, FTIR, DSC and porosity were carried out on concrete samples. Six products with different concentrations, solvent and molecules were tested. The results showed that the application of a water-repellent delays the propagation of the carbonation front. The most efficient products were the silanes which presented a higher penetration depth. Concrete compactness and porosity played also an important role in silane penetration depth. [less ▲]

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See detailCarbonated miscanthus mineralized aggregates for reducing environmental impact of lightweight concrete blocks
Courard, Luc ULg; Parmentier, Véronique

in Sustainable Buildings (2017), 2(3),

At a time when the cement industry is largely responsible for the production of CO2 in the construction sector, it is useful to make this production a reverse phenomenon: that is CO2 capture. The CO2 ... [more ▼]

At a time when the cement industry is largely responsible for the production of CO2 in the construction sector, it is useful to make this production a reverse phenomenon: that is CO2 capture. The CO2 absorption 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 biobased products knows an interesting development in the construction field, especially as thermal insulation panels for walls in buildings. Before identifying and quantifying the basic physical characteristics of concrete made from miscanthus, it is necessary to optimize the composition of the product. The long-term stability as well as the reinforcement may be obtained by means of a mineralization process of the natural product: a preparation with a lime and/or cement-based material is necessary to reinforce the cohesion of the bio-based product. Mineralization process is described as well as the way of producing blocks for CO2 capture by means of accelerated carbonation. Finally, concrete blocks produced with miscanthus mineralized aggregates offer interesting mechanical properties and minimal environmental impact. [less ▲]

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See detailThermal Conductivity of Straw Bales: Full Size Measurements Considering the Direction of the Heat Flow
Costes, Jean-Philippe; Evrard, Arnaud; Biot, Benjamin et al

in Buildings (2017), 7(11), 1-15

The thermal conductivity of straw bales is an intensively discussed topic in the international straw bale community. Straw bales are, by nature, highly heterogeneous and porous. They can have a relatively ... [more ▼]

The thermal conductivity of straw bales is an intensively discussed topic in the international straw bale community. Straw bales are, by nature, highly heterogeneous and porous. They can have a relatively large range of density and the baling process can influence the way the fibres are organised within the bale. In addition, straw bales have a larger thickness than most of the insulating materials that can be found in the building industry. Measurement apparatus is usually not designed for such thicknesses, and most of the thermal conductivity values that can be found in the literature are defined based on samples in which the straw bales are resized. During this operation, the orientation of the fibres and the density may not be preserved. This paper starts with a literature review of straw bale thermal conductivity measurements and presents a measuring campaign performed with a specific Guarded Hot Plate, designed to measure samples up to 50 cm thick. The influence of the density is discussed thoroughly. Representative values are proposed for a large range of straw bales to support straw-bale development in the building industry. [less ▲]

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See detailOn the evaluation of interface quality in concrete repair system by means of impact-echo signal analysis
Garbacz, Andrzej; Piotrowski, Tomacz; Courard, Luc ULg et al

in Construction and Building Materials (2017), 134

According to Concrete Repair Manual as well as ACI 562-16 and European EN 1504-10 standards, a bond strength as a measure of adhesion is one the main feature of repair system necessary to be assessed. The ... [more ▼]

According to Concrete Repair Manual as well as ACI 562-16 and European EN 1504-10 standards, a bond strength as a measure of adhesion is one the main feature of repair system necessary to be assessed. The most common laboratory and engineering method for bond strength evaluation is pull-off test. This is however a semi-destructive method that needs a repair in a place of measurement. Recently, the great interest in nondestructive techniques (NDT) development is noted. Impact-Echo (IE) is considered as one of the most promising methods for this purpose. In this paper, the study on the usability the IE test based on frequency spectrum analysis for bond strength evaluation is analyzed. Both Finite Element Method (FEM) simulation and experimental tests were performed in order to obtain potential relations between IE frequency spectrum and parameters characterizing concrete substrate quality that may affect the final bond strength and the real value of pull-off bond strength measured on samples as well. It was concluded that the IE method can be a useful tool for interface quality and bond strength evaluations in concrete repair system. However, more complex signal analysis, e.g. wavelet analysis, should be considered in the future. [less ▲]

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See detailWhy and how to repair concrete? Compatibility assessment
Courard, Luc ULg

Scientific conference (2016, December 06)

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See detailEvaluation du cursus  Sciences industrielles et de l’ingénieur industriel
Courard, Luc ULg

Conference given outside the academic context (2016)

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See detailSHAPE ANALYSIS OF FINE AGGREGATES USED FOR CONCRETE
HE, Huan; Courard, Luc ULg; Pirard, Eric ULg et al

in Image Analysis and Stereology (2016), 35(3), 159-166

Fine aggregate is one of the essential components in concrete and significantly influences the material properties. As parts of natures, physical characteristics of fine aggregate are highly relevant to ... [more ▼]

Fine aggregate is one of the essential components in concrete and significantly influences the material properties. As parts of natures, physical characteristics of fine aggregate are highly relevant to its behaviors in concrete. The most of previous studies are mainly focused on the physical properties of coarse aggregate due to the equipment limitations. In this paper, two typical fine aggregates, i.e. river sand and crushed rock, are selected for shape characterization. The new developed digital image analysis systems are employed as the main approaches for the purpose. Some other technical methods, e.g. sieve test, laser diffraction method are also used for the comparable references. Shape characteristics of fine aggregates with different origins but in similar size ranges are revealed by this study. Compared with coarse aggregate, fine grains of different origins generally have similar shape differences. These differences are more significant in surface texture properties, which can be easily identified by an advanced shape parameter: bluntness. The new image analysis method is then approved to be efficient for the shape characterization of fine aggregate in concrete [less ▲]

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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 detailRéparation des bétons: principes, matériaux et techniques
Courard, Luc ULg

Scientific conference (2016, April 26)

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See detailEpuisement des ressources et construction durable
Courard, Luc ULg

Scientific conference (2016, April 15)

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See detailA quantitative approach to the concept of concrete repair compatibility
Bissonnette, Benoît; Modjabi-Sangnier, François; Courard, Luc ULg et al

in Dehn, Frank; Beushausen, Hans (Eds.) Concrete Repair, Rehabilitation and Retrofitting IV (2016)

The work reported in this paper is part of a wider research program intended to provide the repair industry with improved fundamental knowledge to implement rational design methods and rules for repairs ... [more ▼]

The work reported in this paper is part of a wider research program intended to provide the repair industry with improved fundamental knowledge to implement rational design methods and rules for repairs. In that regard, there is a strong need to study the fundamental relationships and parameters that underlie the repair compatibility concepts, in particular those relating to dimensional compatibility. In the first part of the paper, classical formulas derived for thick cylindrical specimens were used to analyze the tensile stress buildup in annular restrained shrinkage test specimens, taking into account the restraining conditions the investigated ring test method and the individual concrete properties/phenomena determined experimentally (elastic modulus, creep coefficient, drying shrinkage deformation). By comparing the ring test results with the calculated tensile stresses, the validity and accuracy of the theoretical approach could be appraised. A quantitative approach for the evaluation of the performance of concrete repair in terms of dimensional compatibility was then developed. Derived from the basic strain balance approach (ratio between the total deformability in tension and the drying shrinkage deformation), a parameter referred to as dimensional compatibility index (CI) was introduced in order to analyze the evolution of dimensional compatibility as a function of time for a given concrete mixture, taking into account the actual degree of restraint in the element. Compatibility index evolution curves were calculated for various repair concrete mixtures in order to highlight material behavior relating to composition parameters and temperature. As it requires the evaluation of a limited number of individual properties that are for most readily available (i.e. strength, elastic modulus, shrinkage), the compatibility index expressed in terms of deformation carries a lot of potential as a relatively simple and convenient analytical tool for assessing the cracking sensitivity of concrete repair materials. Overall, it can be stated that a good correlation was found between the ring test results and the tensile stress values calculated based on individual concrete properties / phenomena and that the proposed calculation method lays ground for evaluating quantitatively the dimensional compatibility of repair materials and defining suitable performance criteria. [less ▲]

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