References of "Restoration of Buildings and Monuments = Bauinstandsetzen und Baudenkmalpflege"
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See detailStatic Detection of Thin Layers into Concrete with Ground Penetrating Radar
Van der Wielen, Audrey ULg; Courard, Luc ULg; Nguyen, Frédéric ULg

in Restoration of Buildings and Monuments = Bauinstandsetzen und Baudenkmalpflege (2012), 18(3/4), 247-254

Ground Penetrating Radar (GPR) is a nondestructive technique particularly well adapted to the inspection of concrete structures and can help to determine the structure inner geometry or to detect damaged ... [more ▼]

Ground Penetrating Radar (GPR) is a nondestructive technique particularly well adapted to the inspection of concrete structures and can help to determine the structure inner geometry or to detect damaged areas. When the GPR is used on structures containing thin layers, for example the sealing layer of a concrete bridge deck or the void into a masonry wall, it is important for the radar user to know the minimum thickness required to detect and estimate the thickness of those layers. The theory of thin layer detection is based on a sine wave but, in reality, most commercial GPR systems emit a large frequency band wavelet, which undergoes attenuation into the layer. To analyze the influence of those realistic conditions on the reflection coefficient of a thin layer, we combined experimental measurements and numerical FDTD simulations. The experimental results matched the numerical predictions well, presenting a fast attenuation compared to the theoretical predictions. Nevertheless, for thicknesses inferior to λ/11, the reflection coefficient could still be considered as linearly dependent of the thickness to wavelength ratio. [less ▲]

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See detailChurches and concrete in Liège district: history, architecture and pathologies
Courard, Luc ULg; Paquet, Pierre ULg; Gillard, Anne

in Restoration of Buildings and Monuments = Bauinstandsetzen und Baudenkmalpflege (2011), 17(1), 314

Reinforced concrete is a key element of the architectural evolution and has been specifically involved in the development of religious architecture. Since its discovery in the nineteenth century, this ... [more ▼]

Reinforced concrete is a key element of the architectural evolution and has been specifically involved in the development of religious architecture. Since its discovery in the nineteenth century, this invented material, economic and fire resistant, however showed its limits: cracks, spalling and disintegration are some of the degradations we may observe today. It therefore seems necessary to worry about the current state of churches: these monuments are indeed the testimony of architectural evolution but also landmarks for the neighborhood. In Liege district, Belgium, nine parish churches have been identified as mainly concrete based. For each church, a visual inspection has been realized: this overview let us to make an assessment of the monument, with regard to concrete and reinforced concrete situation. This inspection is the first step for further investigations included into a restoration or renovation process. [less ▲]

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See detailSurfology: what does it mean for polymer concrete composites?
Courard, Luc ULg; Garbacz, Andrzej

in Restoration of Buildings and Monuments = Bauinstandsetzen und Baudenkmalpflege (2010), 16(4/5), 1-12

Surfology is a scientific concept including all surface properties of materials and its influence on adhesion. The study of adhesion of polymer concrete composites is on the border - interface - between ... [more ▼]

Surfology is a scientific concept including all surface properties of materials and its influence on adhesion. The study of adhesion of polymer concrete composites is on the border - interface - between materials science and engineering. Interface quality is clearly influenced by surface properties of materials. Quality is uneasy to define but, at the level of interface, it could integrate all what favours the contact between concrete and polymers, like shrinkage, rigidity, surface roughness, wettability, viscosity…etc. Surfology contributes to understand what will make the contact effective or not, and allow interactions of variable intensities between the materials. Different scales of observation – micro to macro - are needed to exactly represent what happens when materials are put into contact. The objective of the paper is to analyse the effect of surface parameters (surfology) on polymer concrete composites. Influence of water content, roughness and type of material will be taken into account as factor influencing wettability and thermodynamic properties of surface. Viscosity and shear level of resinous materials will be considered in the same way. Engineering point of view will be taken into account through adhesion evaluation and correlated to surface material properties. [less ▲]

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See detailRelation between bond quality and impact-echo frequency spectrum
Piotrowski, Tomasz; Garbacz, Andrzej; Van der Wielen, Audrey ULg et al

in Restoration of Buildings and Monuments = Bauinstandsetzen und Baudenkmalpflege (2010), 16(4/5), 303-314

According to EN 1504-10 and ACI Concrete Repair Manual, bond strength and interface quality are the main features of repair system necessary to be assessed. Pull-off test is most commonly used for bond ... [more ▼]

According to EN 1504-10 and ACI Concrete Repair Manual, bond strength and interface quality are the main features of repair system necessary to be assessed. Pull-off test is most commonly used for bond strength evaluation but growing interest in nondestructive techniques (NDT) is recently noted. Impact-echo (IE) is treated as the most promising one for this purpose. The aim of this paper is to analyze an effect of bond quality on stress wave propagation in repair systems. A group of samples has been prepared in order to obtain repair systems of different bond quality. Prior to repair, quality of concrete substrates has been characterized according different techniques: compressive strength, superficial cohesion, surface roughness index and cracking quantification. Than a polymer-modified repair mortar has been applied. After hardening, IE signals have been recorded and pull-off bond strength determined. The relationships between parameters characterizing surface quality, bond strength, IE frequency spectrum and results of wavelet analysis of IE signal have been analyzed. [less ▲]

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